FePt-based magneto-optical recording medium of mixed

Title: FePt-based magneto-optical recording medium of mixed Author: Dong Kaifeng Degree-granting units: Huazhong University of Science and Technology Keywords: magneto-optical hybrid storage;; perpendicular magnetic recording media;; FePt-based films;; micromagnetic Abstract:
Magneto-optical hybrid storage technology can break the limit of ferromagnetic materials, superparamagnetic limit, which greatly improved the hard disk neodymium magnets recording density. It benefits
Coercivity of ferromagnetic materials with the temperature characteristics, the use of laser-assisted thermal magnetic writing, the signal read out the high sensitivity of GMR heads Inspection
Approach to measuring flux. The key to achieve magneto-optical storage is one of mixed hybrid magneto-optical recording media research and development, this focus on
FePt-based magneto-optical hybrid recording media research and preparation, completion of major studies, including:
Record for the magneto-optical characteristics of mixed
And requirements, prepared by rf magnetron sputtering a different series of FePt films, the films by vacuum annealing heat treatment
Formed L1_0 ordered structure, measurement and analysis of the different sputtering conditions by state and after annealing the film properties and microstructure characteristics
Include: different Ag film thickness and the bottom of the vertical orientation of the FePt single layer film effects; different cooling rates and different retirement annealing
Fire time magnetic properties of FePt film; http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php different film structure of [Fe / Pt] _n and [FePt / Ag] _ (10) Magnetic multilayers studied
; Ni doping on the FePt magnetic properties and Curie temperature. Test results show that: the preparation of FePt single-layer and Ag / FePt bilayers with
Good vertical orientation; annealing process of the cooling rate can significantly affect remanence squareness; Fe / Pt multilayer films can effectively reduce
Ordering temperature of FePt films; by Ni doping method can effectively reduce the Curie temperature of FePt film.
Micro-magnetic method
To simulate the magnetization flip FePt film, the description of a magnetic flip magnetic moment at different times during the distribution of the film
Perpendicular coercivity changes in the relationship with the angle θ (θ is the easy magnetization axis and the angle between the field), and the coercivity with particle size relationship;
Simulated [FePt / X] _ (10) (where X is a non-magnetic material) multilayer film thickness changes in the X multilayer coercivity of the impact; in this
Based on the study of particle size on the noise parameters of the transition zone, the noise parameters of the transition zone, including the transition zone width, perpendicular to the
Record length and location of the track direction of the associated offset parameters. The results show that: FePt single-layer magnetic thin film flip line SW model; with
The grain size increases, the film coercivity gradually reduced, the transition zone noise increases. Degree Year: 2009

Φ-mapping topological current theory and its application in cutting-edge physics

Title: Φ-mapping topological current theory and its application in cutting-edge physics Author: tension of Degree-granting units: Lanzhou University Keywords: superconductors: 4638, bifurcation point: 3840, Vortex: 3659, Vector field: 3348, limit points: 3081, Implicit function theorem: 2661, Evolution
Process: 2525, Equilibrium: 2507, Topology entry: 2267, scalar field: 2175 Abstract:
This paper made use of Professor Duan Neodymium Magnets Yishi the φ-mapping topological current theory, research the ferromagnetic spin-triplet superconductors, two-gap
Superconductor, with two complex scalar field Abelian Chern-Simons model, cosmic string model film world, as well as the steady-state vector field
Bifurcation process.
First, the use of φ-mapping topological current theory, we have come to a ferromagnetic spin-triplet superconductors allow unstable
The conclusion of the formation of magnetic monopoles. We define the topology of a magnetic monopole current, and it is proved that the topological magnetic monopole particles stream flow,
The flow of non-zero value means that the topological magnetic monopoles exist, and the corresponding flow topology is conserved topological charge corresponding to the magnetic monopole magnetic charge.
To make an unlimited volume of the ferromagnetic spin-triplet superconductor with finite energy magnetic monopole monopole anti-monopole can only exist in the form of
. In such a pair of magnetic monopoles, the magnetic monopole and anti-monopole will be Dirac string or a two-quantum vortex connection. That the Dirac
String belongs to SO (3) of the first homotopy group ordinary topology class. In addition, we also pointed out the limits of φ-mapping is precisely this point and the bifurcation point
These magnetic monopole space-time http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets point interaction.
Secondly, we derive the exact two-gap superconductors revised London equation, and with
The single-gap corresponds to the equation were compared. We show that two-gap superconductor in the vortex of soft-core vortex (or vortex called the nuclear row). Special
Do not, we discussed the finite energy vortex (class-Abrikosov vortex) topology, and found that they can be seen as baby
skyrmion in the third direction of extension of the product. In addition, we also pointed out that in the two-gap superconductors, the kink soliton is reversed two
Cycles smooth connection endpoint class-Abrikosov vortex. Finally, we briefly discuss about class-Abrikosov vortex and magnetic single
Great relationship.
Third, we introduce two complex scalar field with the Abelian Chern-Simons model, and the use of φ-
Flow theory, topology mapping, discussed the model self-dual vortex. For each scalar field, we analytically derive a band
With the exact topology of the non-trivial term equation. This topology is, in many literature items are overlooked. In addition, we also received by
Topology of two scalar field equation of their own items contact. We calculated the angular momentum of the vortex system, the result is a single scalar field
Vortex angular momentum of the promotion. We also calculated the system under different boundary conditions, magnetic flux. Further, we briefly discuss
The evolution of the vortex model. As the scroll and found the existence of molecules, the details of the model in the vortex evolution, than the corresponding
Single scalar field model in the vortex evolution is much more complex.
Fourth, the use of φ-mapping topological current theory, we
Abelian Higgs model has been the vortex structure. Thus the film world cosmic string system provides an effective way to describe. This
Kind of approach has the advantage described in the topology associated with the system of physical quantities can be analytically expressed, and the relationship between these quantities
Can be strictly proved. Therefore, the topological properties of cosmic strings for description purposes, this description is very important. In addition, the results
Combined U (1) gauge potential decomposition results, we use a different method again confirmed the previous literature, two conclusions.
Finally,
The use of φ-mapping topological current theory, we introduce a topology to describe the flow properties of vector field topology. In this description, the vector field
Equilibrium can be seen as the topological charge is the winding number, with the parameters change in the phase space moving particles. Based on this
A description, we qualitatively discuss a wide range of steady-state vector field bifurcation process, and found a general method to determine the points
Bifurcation curve of limit points and bifurcation points in the number and direction. Degree Year: 2009

Fetal functional magnetic resonance imaging study

Title: Fetal functional magnetic resonance imaging study Author: Sun Ziyan Degree-granting units: Huazhong University of Science and Technology Keywords: fetus;; magnetic resonance imaging;; spectroscopy;; pregnancy;; prenatal; fetus;; magnetic resonance imaging;; spectroscopy;; pregnancy;; prenatal Abstract:
Part of fetal brain single voxel proton Magnetic lifter spectroscopy of the feasibility study
Dynamic magnetic resonance imaging with the purpose of
Of fetal brain single voxel magnetic resonance spectroscopy is feasible. Materials and methods 50 cases of fetal gestational age 20-40 the number of points according to amniotic fluid volume
Into three groups (more than 6 cases of amniotic fluid volume, normal amniotic fluid group, 21 cases and 23 cases of amniotic fluid less), dynamic magnetic resonance imaging using SSFSE vector film
Like surface observation of fetal head movement, magnetic resonance spectroscopy in the positioning of the fetus on the basis of three orthogonal planes using single voxel point-resolved spectroscopy
(PRESS) sequence line single voxel MR spectroscopy acquisition (TE = 144ms), MRS acquisition is triggered using the breathing technique. Results of multiple amniotic fluid volume,
Normal group and the amniotic fluid http://www.999magnet.com/products/131-magnetic-lifter amniotic fluid amniotic fluid index less groups, respectively (8.0 ± 0.7) cm, normal amniotic fluid volume group and too little amniotic fluid amniotic fluid group
Index, respectively (5.7 ± 1.4) cm and (3.8 ± 1.4) cm, the differences were statistically significant (F = 17.95, P <0.001), polyhydramnios
Frequent fetal movement group, MR imaging can be observed film fetal body parts of more than flip, stretch, and turned around, collecting magnetic resonance spectroscopy to distinguish
, Lower, metabolites on the line split into a jagged peak, spectrum a success rate of 0 (0 / 6), amniotic fluid volume normal fetal head movement
Reduced, lower resolution magnetic resonance spectroscopy acquisition, metabolites can be distinguished in the spectrum, but has obvious noise, the success rate of spectral
42.58% (9 / 21), oligohydramnios, fetal activity was limited group, magnetic resonance spectroscopy acquisition success rate, metabolites on the line to distinguish
Rate. 95.65% success rate spectrum (22/23), normal amniotic fluid volume and amniotic fluid group composed of the power difference was less significant
(X ~ 2 = 4.21, P <0.05). Conclusion proton spectroscopic imaging of fetal brain is feasible, in the normal fetal brain development and disease diagnosis side
Surface has an important value.
The second part of the normal fetal brain development in magnetic resonance spectroscopy study
Objective To investigate the normal fetal
Child brain development and changes in metabolite levels. Methods 35 cases of pregnant women met the inclusion criteria, of which 12 cases of mid-pregnancy, late pregnancy 23
Cases, gestational age 20 weeks to 40 weeks, mean gestational age 34.6 weeks. Within 1-2 days after ultrasound use single-shot fast spin-echo sequence
(SSFSE) line of conventional MR scanning of fetal brain, fetal brain scanning plane including axial, coronal and sagittal. Three orthogonal in the fetal brain
Plane location on the basis of the basal ganglia and the semi-oval center region of interest (VOI) were triggered using breathing techniques, the use of fixed-point resolution wave
Spectral sequence (PRESS) single voxel ~ 1H MRS line scan, (TE, respectively 144ms and 35ms). MRS measurements are given automatically by the machine, the measured
Set of metabolites, including N-acetyl aspartate (NAA), choline (Cho), creatine compounds (Cr), inositol (mI), Valley
Acid and glutamine (Glx), etc. Other parameters include the rms noise (RMS noise) and the creatine signal to noise ratio (Cr SNR). Select
Segment of the study group with gestational age matched 16 normal fetuses as controls. Results of normal fetal head circumference, biparietal diameter line, abdominal circumference, femur length and
No significant difference between the control group, brain MRI and post-natal examination found no abnormalities, TE = 144ms, the fetal brain MRS can detect three
Major peaks, respectively, Cho peak, located at 3.2ppm, Cr peak, located at 3.0ppm, NAA peak, located at 2.02ppm. Cho peak for the first
Peak before 34 weeks pregnant, Cr peak for the second peak after 34 weeks pregnant, NAA peak for the second peak, and the newborn after birth, similar spectrum, NAA
Peak at 22 weeks pregnant can already tell, can not detect lactic acid or a lower peak level, MI peaks can be detected, located 3.56ppm; TE = 35ms
, Can be detected Cho peak, Cr peak, MI peak, NAA peak and the peak of glutamate and glutamine (Glx). As gestational age increases, TE = 144
Time, NAA / S increased (P = 0.007, r ~ 2 = 0.20), Cho / S reduced (P = 0.005, r ~ 2 = 0.22), Cr / S changes with gestational age is unknown
Significant (P = 0.96, r ~ 2 = 0.001). TE = 35ms, when, NAA / S increased (P = 0.05, r ~ 2 = 0.21), Cho / S decreased (P = 0.014,
r ~ 2 = 0.17), MI peak decreased (P = 0.045, r ~ 2 = 0.12), Cr / S did not change significantly with gestational age (P = 0.2, r ~ 2 = 0.049).

The third part of the normal fetal brain development of MRI and DTI research
The purpose of combined single-shot spin-echo sequence and diffusion tensor imaging
Observe the performance of normal fetal brain development. Methods SSFSE sequence and diffusion tensor imaging of 17 cases of 20 to 39 weeks of normal fetal intrauterine
Child brain. Gestational age assessment based on the maturity of the brain back, gray and white matter of stratification, ADC maps and FA maps in different parts of the brain tissue level measurement
Both diffusivity and fractional anisotropy values, and its statistical analysis. Results (1) 20 to 23 weeks of fetal brain structures form the basic shape
Into, this section shows that the brain showed a gestational age of five-layer structure of a typical 24 to 27 weeks of gestation the fetus was a typical three-layer structure. Remaining 27 weeks leave after 2
Layer structure. (2) 20 weeks cortex is smooth, lateral fissure can be seen, with increasing gestational age, cortical tortuous, concave, gradually gyrus
, Followed by the formation of sulci are deeper, 30 weeks gyri, sulci obvious. (3) frontal lobe, occipital lobe white matter and basal ganglia ADC Mean
Were 1.83 ± 0.3μm ~ 2/ms, 1.75 ± 0.1μm ~ 2/ms and 1.65 ± 0.1μm ~ 2/ms, the mean ADC value of CSF
2.9 ± 0.6μm ~ 2/ms. Basal ganglia and the frontal lobe, occipital lobe white matter mean ADC significantly. Frontal lobe, occipital lobe and basal ganglia
Mean ADC value decreased with increasing age, a linear negative correlation with age. (4) 20 weeks pregnant can be traced to the sensory-motor fibers in the brain
Paraventricular, located in the middle of the band, as gestational age increased, the bilateral internal capsule limb of the sensory-motor fibers can clearly show the direction of the head and tail was
. After 20 weeks of pregnancy can be traced to the knee and press the corpus callosum white matter fibers, internal capsule, with the hind legs of the FA values ​​increased with increasing gestational age. Conclusion Alliance
And DTI imaging sequence together SSFSE accurate and comprehensive evaluation of the fetal brain can be real with the gestational age of maturation process variation.

The fourth part of the fetal three-dimensional magnetic resonance imaging study
Objective To investigate the three-dimensional magnetic resonance imaging in normal and abnormal structure of the fetal
Aspects of clinical value. Methods 50 cases of ultrasound diagnosis of fetal congenital malformations or suspected fetal maternal line of MRI, aged 21 to 32 years,
Average of 25.4 years, 20 to 38 weeks gestational age, average 28.6 weeks. MR imaging using single-shot fast spin-echo sequence (SSFSE), in pregnant
Abdominal three-plane positioning of women on the basis of routine fetal head and chest and abdomen axial, coronal and sagittal scans, 41 patients with three-dimensional fast
Imaging steady state precession sequence (3D-FIESTA) line of three-dimensional fetal imaging. 9 cases using three-dimensional spoiled gradient echo sequence (3D-FSPGR) sequence
Line three-dimensional imaging of fetal colon, three-dimensional image transmission to the image post-processing workstation. MRI, ultrasound examination at 1 to 2 days
, MRI examination of the fetal autopsy and follow-up. 2D and 3D ultrasound and MR images by two physicians and two ultrasound
Radiologists double-blind analysis. After the results of autopsy and follow-up study of fetal malformations in 58 cases, of which 44 single malformation cases,
4 cases of two malformations, 2 cases of three malformations, (of which eight cases of anencephaly, meningoencephalocele 3 cases, small head malformation, cervical cystic lymph
The tumor in 9 cases, conjoined twins in 4 cases, 5 cases of congenital diaphragmatic hernia, Hirschsprung's disease in 4 cases, 6 cases omphalocele, A ventral cleft in 4 cases, different body pedicle
Normal in 1 case, clubfoot five cases), 3D-US checks true positive rate was 89.66% (52/58), specificity of 98.11% (52/53),
3D-MRI examination of true-positive rate was 93.10% (54/58), specificity of 98.18%, the difference was not statistically significant. However, a total of three-dimensional magnetic
Resonance imaging field of vision, organization, high resolution, multi-plane can observe the surface structure of the fetus and fetal disease. Discuss the three-dimensional MRI can clearly
To the surface structure of the fetus surface reconstruction, can visualize the structure of the surface features of interest, three-dimensional shape and surface structure between the bit
Relation that can serve as an important supplement to two-dimensional imaging, ultrasound, especially for those who can not be confirmed or ambiguous cases, the diagnosis side
Law is an effective supplement. Degree Year: 2009

The physical properties of magnetized water and the biological effects

Title: The physical properties of magnetized water and the biological effects of Author: Bo Deng Degree awarded by: University of Electronic Science and Technology Keywords: magnetic treatment of water;; Magnetic lifter magnetic field;; infrared spectroscopy;; biological effects Abstract:
Water is one of the most familiar substances, is the basis for the existence of life, and the organism in about 70 to 80% in the proportion of
. It can be said, there is no life without water. But the water in the end, what kind of molecular structure? What features it has? Are worthy of our full
Face in-depth study. After the magnetic field changes the characteristics of the water has been followed for many years. Meanwhile, the magnetic treatment of water for biological or human
Have no effect on the body? What kind of impact? Its biological effects that? And other issues that researchers have been interested. Therefore, it is
Necessary for the magnetic field of the physical properties of water to do more comprehensive research. In this paper, we use the technique of infrared spectroscopy
A magnetic field on the physical properties of water, water and organic molecules such as ethanol interaction characteristics and produce some of the phenomena, and to explore the
Are reasons for these phenomena. Finally, the use of Fourier transform infrared spectroscopy and other methods of magnetic treatment of water to do some preliminary study of the biological effects
. The main work of this paper summarized as the following sections:
1. A semiconductor tester, contact angle, infrared spectroscopy, ultraviolet
Spectroscopy and X-ray diffraction study of http://www.999magnet.com/products/131-magnetic-lifter the magnetic field on water and other physical properties. It was found that: the magnetic field can increase the conductivity of water,
And the longer the magnetic treatment, the greater the increase in conductance. By measuring the contact angle of water and found water in the hydrophobic surface of the copper and graphite
After the contact angle slightly decreases in the magnetic field, indicating that the magnetic field treated water through surface tension decreases, resulting in easier on the solid surface
Infiltration. And the magnetic field can significantly change the spectral characteristics of the water. Water treatment by magnetic field intensity of UV absorption enhancement, and over time
Increased with the increase, it decreases with the wavelength of the exponential increase. X-ray diffraction experiments confirmed that the water can have a magnetic field, magnetic office
Water management and interaction with the magnetic nano-Fe_3O_4, thus confirming the existence of water molecules that can be magnetized group. Magnetic treatment
Water and water in the far, in the infrared and near infrared absorption and Raman scattering spectra are significantly different, only the intensity increased, and the occurrence
The absorption peak of the frequency shift as well as some new absorption peaks at 2800 ~ 5500cm ~ (-1) of infrared absorption peak intensity with that
Obvious saturation effect and the relaxation effect, 8050cm ~ (-1) at a new strong absorption peak. In short, experimental results show that the magnetic field
Does change some of the characteristics of water, these are not observed in the past a new phenomenon.
2. IR study of static
Magnetic field on water and ethanol, methanol and acetone mixture of organic molecules. And not the result of the applied magnetic field in a mixture of comparison,
Water and ethanol, methanol and acetone mixture of the infrared absorption spectrum changed significantly, but it is also different from ethanol, methanol and acetone
The infrared absorption spectrum, indicating that the magnetic field changes of ethanol, methanol and acetone and their own molecular structure and the interaction between water molecules
With the formation of a ketone - water and alcohol association complex - water-association complex structure, resulting in changes in the infrared absorption spectrum.
3. Profit
Professor Pang Xiaofeng the water with the theory of magnetization mechanisms, analysis of magnetic water treatment has been the nature of the experimental results and the root causes
, And describes the mechanism to generate these properties change.
4. On the biological effects of magnetic treatment of water has been studied, results show that the magnetic
Treated water has a significant biological effects. In the magnetic treatment of water on the biological effects of immunocompromised mice study found that magnetic treatment of water to avoid
Epidemic of low immune function and digestive function of the number of indicators have improved significantly and facilitating role. By IR experiments, found
Rats drinking magnetized water will not be long-term liver lung and spleen tissue structure of its impact. Degree Year: 2009

Considering the effect of non-uniform critical current density of high-temperature superconductors and AC loss of flux jump theory

Title: Considering the effect of non-uniform critical current density of high-temperature superconductors and AC loss of flux jump theory Author: Zhao Yufeng Degree-granting units: Lanzhou University Keywords: high-temperature superconducting material;; flux jump;; AC losses;; high-temperature superconducting thin films;; non-uniform distribution of critical current density effect;; Bean model;; Kim model;; flux dynamics;; transmission loss ;; magnetization loss;; hysteresis loop;; magnetic thermal instability;; Norris equation;; Maxwell equations Abstract:
High-temperature superconductors at very Magnetic lifter low temperature environment of the flux jump instability phenomena and conditions in effect under alternating energy loss is directly related to the superconducting device and system security and stability, superconductor applications are the fundamental issues of concern His research has been highly valued. As the high-temperature superconducting materials in the preparation process there is inevitably a large number of various types of lattice defects caused by the pinning potential within the superconductor critical current density and uneven distribution, then the associated loss of flux jumps and exchanges become Superconducting devices and systems security design and optimization of key scientific issues. In this paper, the local magnetic thermal insulation is assumed from the perspective of the interaction of non-uniform distribution of critical current density effect on the flux jumps and the impact of exchange losses and high-temperature superconducting thin films of magnetic field and current density distribution and loss of in-depth study , and obtained some meaningful results.
First, for high-temperature superconductors the critical current density of magnetic flux jumps non-uniform distribution of effects, from the perspective of the magnetic interaction of environmental hot initial rate of change of temperature and magnetic field effects by solving the first flux jump prediction equation established a critical flux jump effects of non-uniform distribution of current density the theoretical model, while the critical state theory in the context in which heat distribution and temperature response shows high-temperature superconductors magnetic flux jumping resolution representation. In this paper, the theoretical model can predict the existing experimental data and numerical results and theoretical calculations found: non-uniform distribution of the critical current density effects seriously affect the flux jump phenomenon, the generation of magnetic flux jumps are inhibited, http://www.999magnet.com/products/131-magnetic-lifter and with the the characterization of the critical current density in different regions of the parameters intensity difference γ = J_ (cw) / J_ (cs) increases, the inhibition becomes more significant.
Second, consider the self-field equations based on the role of Norris, the critical current density analysis of the effects of non-uniform distribution of high-temperature superconducting wire transfer cylinder exchange loss of influence. Calculated that: superconducting critical current density along the wire cylinder radial increments from the inside and outside the non-uniform way to effectively reduce the transmission loss. When the normalized transport current is larger or close to the critical current, critical current density of the non-uniform effect on the transmission loss of more significant; when the normalized transport current is small, its impact under normal circumstances is negligible. Critical current density along the radial cross-section from the inside and outside the square a linear way and loss of behavioral change and to step-like way different. In particular, cylindrical cross section of superconducting critical current density at the boundary of the distribution is extremely important for reducing the transmission loss.
Finally, consider the two-dimensional high-temperature superconducting thin film superconductivity and magnetic field effects and the distribution of current density characteristics of the AC losses of superconducting thin films non-uniform distribution of critical current density effect. Calculated that: flat and thin-film superconducting samples of external applied magnetic field and transport current of the electromagnetic response is essentially the difference. Strong magnetic field, respectively, linear and nonlinear superconducting plate in the form of penetrating and film. No flat field in the superconducting region is zero and the critical current density to J_c transport current in the film critical current density of J_c field area in the non-zero and not its continuous change. Film transmission loss of the critical current density on the qualitative effect of non-uniform distribution of geometric shapes with other superconductors are basically the same, when the film magnetization in the high field critical current density loss of non-uniform effects gradually disappear.
In short, through this paper, high-temperature superconducting materials, AC losses of the flux jump and the critical current density non-uniform distribution of effects research, and correctly predict the accurate measurement of field flux jump occurs, the exchange loss and other performance parameters provide a good theoretical basis, and this study of high-temperature superconducting devices and high-temperature superconducting thin film devices for accurate design and application of great significance.

Marine reconnaissance robot propulsion system of anti-control chaos

　　Title: Marine reconnaissance robot propulsion system of anti-control chaos
　　Author: Meng Zhaojun
　　Degree-granting units: Shenyang University
　　Keywords: chaotic anti-control;; nonlinear control;; marine reconnaissance robots;; anti-detection capabilities;; propulsion systems;; differential geometry theory
　　Abstract:
　　The research of marine propulsion systems Chaotic reconnaissance anti-robot control problems, improved anti-chaos control method, and the Neodymium Magnets application of the propulsion system presents a pre-research program.
　　Marine reconnaissance robot propulsion system is a typical multi-variable nonlinear time-varying systems, nonlinear systems dynamics in this in-depth study of chaos is bound to involve research. Motor system at home and abroad in the chaos of the research in the early stages of exploration, reconnaissance robot for underwater propulsion system chaotic motion studies is facing enormous difficulties. How to chaos science applied to the robot propulsion system which, when it comes to harmful chaos control, chaos and beneficial anti-controlled two issues. Anti-control propulsion system, that of chaos, is a challenging and interdisciplinary nature of the new issues, the study has important theoretical and practical value. This reconnaissance robot for marine propulsion system produces a unique sound pattern to reduce the hidden problem, the application of its anti-control chaos active in the anti-detection research, the main contents are summarized as follows:
　　First, the use of wavelet phase space reconstruction of chaotic attractors determine whether the system is chaotic, which is chaotic anti-control study of the most important issue. Marine reconnaissance robot propulsion system when running in deep-sea noise and chaotic signals generated by essentially different. To solve the existing time series phase space reconstruction methods reconstruct information redundancy, the paper will be introduced to the wavelet transform into the phase space reconstruction. Confirmed that the wavelet phase space reconstruction method can not only accurately reconstruct the chaotic characteristics of the original system, the system can reconstruct the original period features, double period features and characteristics of the proposed cycle is an effective way to determine the chaos.
　　Second, the differential geometry theory is introduced to the permanent magnet propulsion motor system, the control object is difficult to solve nonlinear control problems. The subject of the use of state coordinate transformation and state feedback transformation, completed the permanent magnet propulsion motor of the non-interactive multi-input multi-output control design. On this basis, adaptive feedback linearization theory will be applied to permanent magnet propulsion motor system parameter uncertainty in the study. The results showed that: the theory of differential geometry can be permanent magnet propulsion motor nonlinear systems without any loss of useful information into a linear system under the conditions, based on differential geometry theory of nonlinear control techniques used in its rich field of motor control research tools.
　　Third, the system controller for brushless motor of serious non-linear, and reconnaissance robot propulsion system on the stability of the overall impact on the system, including permanent magnet brushless motor, propeller, three parts of a complete underwater robotic reconnaissance mathematical model of the robot system equivalent transformation, the application of the theory of differential geometry can be accurately analyzed the conditions for linearization. According to the study pointed out the underwater reconnaissance robot translation between the equation and the propulsion system does not directly relevant, and accordingly Conclusion precise time delay state feedback linearization technique proposed an underwater surveillance robot propulsion of Chaos anti-control method. Simulation shows that: to ensure the normal operation of the basic premise of the robot, propulsion Lee chaotic attractor shape chaos chaotic state by adjusting the parameters to change the anti-controller.
　　Fourth, the time delay state feedback exact linearization chaotic anti-control method, based on reconnaissance robot to solve the underwater propulsion motor of the low-pass filter characteristics, presents a propulsion motor for the time delay state feedback control of chaotic pulse anti-control method. By changing the anti-chaos parameter controller and rectifier method and then change the input signal is proposed to change the propeller noise, a unique line spectrum characteristic of technical solutions to the unique characteristics of the noise from the chaotic state into a moment of change, so as to achieve The purpose of confusing the enemy. Anti-control of chaos in the application of marine reconnaissance robots do try.
　　Finally, the proposed control strategy to do the simulation and experimental platform developed in the group and carried out experiments on the prototype, computer simulation and experimental results are basically consistent with theoretical expectations.
　　Degree Year: 2009

Si-based diluted magnetic semiconductors X-ray absorption spectroscopy study

　　Title: Si-based diluted magnetic semiconductors X-ray absorption spectroscopy study
　　Author: Jiang Yong
　　Degree awarded: China University of Science and Technology
　　Keywords: X-ray absorption fine structure;; Fe_xSi_ (1-x);; Mn_xSi_ (1-x);; diluted magnetic semiconductors;; magnetron sputtering;; molecular beam epitaxy;; XRD;; Raman
　　Abstract:
　　This thesis using synchrotron radiation X-ray absorption fine structure spectroscopy (XAFS) technique, combined with X-ray diffraction (XRD) and Raman spectroscopy joint study of experimental methods of sputtering magnetron sputtering and molecular beam epitaxy prepared Si-based diluted magnetic semiconductor thin film structure, to obtain the Fe-doped and Mn-doped Si-based thin films Fe and Mn atoms in the distribution and structural Neodymium Magnets parameters such as coordination environment. At the same time an effective single-particle-based self-consistent real space relativistic Green's function of FEFF8 theoretical calculations, and Mn atoms by Fe atoms doped Si-based diluted magnetic semiconductor system Fe atoms and Mn atoms occupying the typical building model, analysis the Fe atom and Mn atom in the system and the mass of the existing form, clear the Fe atom and Mn-doped Si-based diluted magnetic semiconductor thin films of Mn atoms mainly substitutional form, Fe atoms exist in the form is determined by the temperature of the sample preparation. These are Si-based diluted magnetic semiconductors provide a basis for the controllable preparation.
　　1.Fe doped Si-based diluted magnetic semiconductor thin film structure
　　The use of XAFS and Raman spectroscopy and other methods of magnetron sputtering deposition method were prepared Fe_xSi_ (1-x) thin film magnetic semiconductor structures. Raman results show that the samples prepared at room temperature does not exist in the metal clusters or Fe-Si Fe compound phase, 473K temperature prepared samples have FeSi_2 compound phase exists. Program to simulate the use of FEFF8 Fe occupy Si lattice substitution bit, square and hexagonal interstitial space bit, three theoretical models most representative of the radial structure function curve, compared with the experimental curve, a clear presence of Fe in the sample form depends on the sample preparation temperature. Preparation of the samples at room temperature, Fe atoms into the Si lattice, the main alternative to digital form Fesi exist; and when the preparation temperature reaches 473K, the Fe film samples mainly FeSi_2 compounds form. At the same time, the use of XAFS 473K under the conditions studied, using molecular beam epitaxy prepared Fe_xSi_ (1-x) thin film magnetic semiconductor structure, the findings with previous results obtained are consistent, that is, when the temperature reached 473K, after preparation, Fe Si atoms distributed to the media, the major reaction with Si http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets atoms to produce FeSi_2 compounds.
　　2.Mn doped Si-based diluted magnetic semiconductor thin film structure
　　Of XRD and XAFS study prepared under the conditions of 473K Mn_xSi_ (1-x) thin film magnetic semiconductor structures. XRD results show that two different Mn contents of samples do not exist in clusters or metal Mn Mn-Si compound phase. Mn K edge XAFS results show that for all Mn-doped content (3.0%, 10.0%) samples, Mn Si atoms are already distributed to the media. EXAFS fitting results show that, Mn atoms with nearest neighbor Si atoms with average bond length is 2.35 (?), With a median of about 4.1, and Mn occupy the alternative position of the structural parameters are similar. Simulation program using FEFF8 Si lattice of Mn atoms occupy the alternative position, square and hexagonal interstitial gap-bit, three theoretical models most representative of the radial structure function curve, compared with the experimental curve, clear of Mn atoms in the sample to replace the main bit of form.
　　Degree Year: 2009

aeromagnetic anomaly gradient method of extension and conversion

　　Title: aeromagnetic anomaly gradient method of extension and conversion
　　Author: Li Haixia
　　Degree-granting units: Zhejiang University
　　Keywords: aeromagnetic total field anomaly;; horizontal gradient;; vertical gradient;; extension;; frequency domain;; conversion surface
　　Abstract:
　　In order to meet the upcoming aeromagnetic gradient measurements, carried out this aerial magnetic gradient anomalies extension and conversion method. Aeromagnetic anomalies extension is commonly used in data processing methods, including plane upward continuation, flat and curved downward continuation extension. Plane extension is usually used to suppress or highlight the short-wavelength anomalies; surface extension method used to obtain data for Neodymium Magnets different interpretations, including song of the flat, level of music and song of the song. Gradient anomalies and aeromagnetic anomalies ΔT same extension also needs to deal with. One of the tasks of this paper is to study the gradient aeromagnetic anomalies for extension of fast, accurate and practical method.
　　Frequency domain fast Fourier transform (FFT) is the most commonly used aeromagnetic anomalies plane extension method. Upward continuation using FFT method is very stable, upward gradient abnormal extension of the plane still use this method. However, the FFT is very unstable downward continuation, magnetic anomalies on the next flight delay is usually not more than three times the pitch. Gradient anomaly compared with the total field anomaly usually contain more high frequency information, downward continuation method when the stability requirements are higher. Surface extension commonly used method is the equivalent source method and the Taylor series expansion, the main problems of these methods is to calculate the volume of work and the depth of downward continuation is limited, making the method very limited usefulness. This paper attempts to develop iterative methods for nearly two years, and interpolation - iterative gradient aeromagnetic anomalies transplanted to the plane downward continuation and extension of the surface. First, the use of model http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets data on the validity and accuracy have been tested, results showed that the iterative method for gradient data of the plane under the extension, and interpolation iterative method for gradient surface extension with high accuracy, to under extension of depth, and the results are stable. Through the noisy model data analysis of the results of random interference on the impact of extension, the results also proved that the iteration method and interpolation - iterative method has good stability.
　　The second part of this content is aeromagnetic total field and gradient components of the conversion, systems studied in the frequency domain conversion using the total field gradient, the total field and gradient conversion gradient between the conversion. Potential field in the frequency domain to convert has a simple expression to calculate the speed, etc., is often used to achieve conversion of the potential field method. However, conversion in the frequency domain to achieve the total field gradient and the gradient between the conversion, such conversion filtering operator frequency axis at the origin or existence of singularity, that is, the denominator is zero. This means that the conversion factor in the existence of the singularity of these frequencies can not be sampled, it can not be calculated using discrete Fourier transform on the conversion amount of the corresponding frequency spectrum values. We move like the introduction of the discrete Fourier transform, filtering operator function to solve the problem of existence of singularities, to achieve any total field and gradient convert any conversion between the two gradient components calculated. Verified by model method has high accuracy.
　　Convert the frequency domain method for the field on the plane, model test results show that when calculating the surface undulating, the use of the method of conversion will have a relatively large error. We combine the interpolated - iterative surface extension, converting the frequency domain method is extended to the total field and gradient on the surface of conversion, to achieve a surface gradient component aeromagnetic anomalies and rapid conversion.
　　We use the measured total field and gradient aeromagnetic data plane iterative downward continuation, and interpolation - iterative extension of the validity of the surface was examined. The results prove that the method has good stability and high accuracy; very fast method to ensure the practicality of the method. The measured total field and gradient of the conversion calculation, and convert the results compared with the measured data analysis, the conversion from the total field gradient, and gradient between the conversion results with the measured data are well consistent with the gradient , but the two groups compared to the results, the gradient between the results of conversion consistent with the measured data better; by the conversion of the total field gradient with the measured total field compared to a loss of some high-frequency information, but the overall pattern is also abnormal good relationship. In this case the results of the conversion of good consistency with the measured data to verify the validity of the conversion method, but also proves the reliability of the measurement parameters. The example calculations for the aeromagnetic anomaly gradient approach to extension and conversion applications provide some frame of reference.
　　Degree Year: 2009

Magneto-rheological vibration suppression intelligent boring bar from the theory and method

　　Title: Magneto-rheological vibration suppression intelligent boring bar from the theory and method
　　Author: Kong Tianrong
　　Degree-granting units: Zhejiang University
　　Keywords: deep hole boring;; flutter suppression;; magneto-rheological fluid material;; intelligent boring bar;; variable structure stiffness;; nonlinear stochastic optimal control;; semi-active vibration control
　　Abstract:
　　Precision Hole for common flutter, this paper combined with the National Natural Science Foundation "from the magneto-rheological fluid-based intelligent boring bar vibration suppression component theory and method" (item number: 50405036) and Zhejiang Natural Science Foundation " magneto-rheological fluid from intelligent boring bar vibration suppression component theory and method "(item number: Y104462), through theoretical analysis, numerical simulation Neodymium Magnets and experimental verification of the application of magneto-rheological techniques to suppress the process of boring issues of cutting chatter in-depth study of the system.
　　Chapter 1, describes the research background of the degree and significance of details at home and abroad for cutting chatter control technology research status, clear cutting tool chatter control technology development, presented the main research papers.
　　Chapter 2, the establishment of a Boring flutter vibration mechanics model system to study the root causes of flutter, while the spindle speed cutting method, the flutter suppression mechanism has been studied, has been the nature of its causes flutter suppression. On this basis, the structural stiffness and damping the impact of change on the stability of the system conducted in-depth study of proposed variable structure stiffness flutter suppression method, and theoretically confirmed it with variable speed cutting method has the same effect.
　　Chapter 3, based on the characteristics of magneto-rheological fluid material presented to support stiffness controllable magneto-rheological vibration suppression since the design of intelligent boring bar, and key structural vibration suppression of magneto-rheological fluid unit of the parameter optimization. ANSYS finite element simulation of the optimized structural parameters, results showed that the main performance indicators to meet the design requirements.
　　Chapter 4, the first load through the static method of intelligent boring bar of the rigidity and damping characteristics of the test, found that http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets after the boring bar in the static magnetic field flexibility and damping characteristics change significantly; second excitation method using transient and steady-state excitation method were carried out on intelligent boring bar dynamics test and analysis of intelligent boring bar of the rigidity and damping on the size of the magnetic field intensity changes of its dynamic characteristics and vibration frequency, amplitude, and the relationship between the magnetic field strength; Finally, intelligent boring bar response time for the test. Research was supported by the magneto-rheological vibration suppression intelligent boring bar from the variation of static and dynamic characteristics and modeling, will provide effective control strategy to develop its scientific basis.
　　Chapter 5 presents a model based on Kelvin and Maxwell models of magneto-rheological fluid material constitutive model, the establishment of a Euler-Bernoulli beam model based on magneto-rheological vibration suppression intelligent boring bar from the dynamic model, with consumption and with San function of intelligent boring bar Lagrange equation of the dynamic characteristics of a theoretical analysis and numerical simulation. In order to meet the requirements of real-time control, but also the introduction of Bouc-Wen model, this model was established based on kinetic model of intelligent boring bar, and the theory of nonlinear least-squares method to identify the relevant parameters, and finally the numerical simulation, The results show that it can accurately describe the dynamics of intelligent boring bar, the development of real-time control strategy for follow-up basis.
　　Chapter 6, according to the process of boring chatter Zhen, development and maturity characteristics of each stage, the whole boring process divided into two situations, and on this basis have raised a non-linear stochastic optimal semi-active control strategies and semi-active variable stiffness control strategy. For non-linear stochastic optimal semi-active control strategy, its control law was derived, also put forward the corresponding performance criteria, and for the control simulation. For semi-active variable stiffness control strategy, its control parameters optimized for the theoretical analysis and numerical simulation to do the relevant research.
　　Chapter 7, in order to verify the proposed front of the correctness of the theory and methods, established on the lathe CA6140 magnetorheological vibration suppression intelligent boring bar from the cutting chatter control experiment platform for the relevant experiments. First non-linear stochastic optimal semi-active control strategies Chatter control experiments to study the damping effect of the actual and verify the theoretical analysis results are correct. Secondly, for semi-active variable stiffness control strategy of cutting chatter suppression experiment, and verified by experimental methods to optimize the control parameters of reasonableness of the results.
　　Chapter 8 summarizes the paper's research and innovation, and prospects for future research.
　　Degree Year: 2009

人羊膜间充质干细胞移植治疗大鼠脑损伤

题名:人羊膜间充质干细胞移植治疗大鼠脑损伤
作者:王公平
学位授予单位:郑州大学
关键词:羊膜;;间充质干细胞;;量子点;;神经生长因子;;菲立磁;;移植;;脑损伤;;肿瘤标志物
摘要:
 研究背景:脑损伤是严重威胁人类健康的疾病之一。目前对重度脑损伤导致的神经功能缺失,治疗难以达到满意的效果。近年来干细胞研究的进展给脑损伤的治疗带来了希望,取得了令人鼓舞的治疗效果。干细胞移植治疗脑损伤能够改善宿主的神经功能,可能的机制有:外源性干细胞在宿主体内的内分泌作用和机体自身神经细胞的旁分泌作用,使局部的神经营养因子聚集,改善了神经细胞的生存环境,使外源性干细胞更易向神经细胞转化并与宿主的神经细胞建立突触联系,具体的确切机制仍需进一步研究。目前Neodymium Magnets移植干细胞治疗脑损伤的途径有脑损伤区原位移植、通过脑脊液循环及血液循环进行移植,均能对神经功能有所改善。采用何种移植途径能最大程度改善宿主的神经功能,尚没有明确的结论。对各种移植途径进行治疗效果系统比较的研究报道尚未见到,实验将给与探讨,为干细胞移植治疗脑损伤提供实验依据。干细胞移植治疗脑损伤的研究手段多是采用处死动物后获取组织标本,进行病理学的观察。如何活体观察外源性干细胞在宿主体内的存活情况,是干细胞移植研究的难点和重点。在小鼠胚胎干细胞移植治疗大鼠脑损伤的研究方面,应用1.5T核磁共振仪成功进行了活体观察,取得了满意的观察效果。在人羊膜间充质干细胞移植治疗脑损伤的研究方面,报道较少,有关活体示踪羊膜间充质干细胞在宿主体内存活情况的研究也没有见到报道。本文采用人羊膜间充质干细胞进行体外标记后移植治疗脑损伤大鼠,3.0T核磁共振活体示踪细胞的存活迁移情况。
 研究表明,神经生长因子对神经元的生长分化及功能的维持具有重要作用。神经生长因子诱导干细胞向神经元样细胞转化的研究已有多篇报道,联合神经生长因子与外源性干细胞移植治疗脑损伤有人进行了研究,对宿主神经功能的改善有一定作用。在脑损伤区长期维持神经生长因子的有效浓度,是神经生长因子联合干细胞移植治疗脑损伤的关键问题,由于神经生长因子通过血脑屏障能力弱,外周血管给药的途径难以有效进入脑损伤区,另外神经生长因子半衰期短,难以在脑损伤区长久维持有效浓度,因此如何使神经生长因子进入脑损伤区并维持有效浓度仍需进一步研究。本文采用量子点观察神经生长因子纳米化后进入羊膜间充质干细胞的情况,通过羊膜间充质干细胞携带神经生长因子进入脑损伤区,取得了满意的效果。
 外源性干细胞移植入机体后,对宿主的影响目前尚无明确结论,仍需要研究人员进行探讨。本文通过采集血液检测血常规及肿瘤标志物,了解干细胞移植对脑损伤大鼠的影响,并通过核磁共振观察有无新生物出现。
 综合以上研究情况,我们将在人羊膜间充质干细胞移植治疗脑损伤的移植途径、神经生长因子的给药方法、羊膜间充http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets质干细胞移植治疗脑损伤对机体的影响及活体示踪进行探讨,为脑损伤的临床治疗提供依据。
 目的:
 第一,探讨体外分离、培养和纯化羊膜间充质干细胞(Mesenchmal stem cells,MSCs)的方法;第二,探讨应用量子点神经生长因子纳米粒和Fe_3O_4纳米颗粒(菲力磁)标记羊膜MSCs的可行性及适合条件,并探讨应用3.0T磁共振活体观察负载Fe_3O_4纳米颗粒的羊膜MSCs在大鼠脑损伤区存活迁移的可行性;第三,探讨羊膜MSCs作为载体携带神经生长因子纳米颗粒移植治疗大鼠脑损伤对大鼠神经功能的改善作用;第四,探讨羊膜间充质干细胞移植治疗脑损伤的安全性。
 方法:
 第一,羊膜MSCs的分离培养与鉴定无菌条件下取正常足月剖腹产胎盘的羊膜,生理盐水充分冲洗后,用0.25%的胰蛋白酶室温消化30min,然后用含1.0g/L胶原酶Ⅳ的DMEM/F12培养液37℃消化1h,200目滤网过滤,制成单细胞悬液,用含10%胎牛血清(fetal bovine serum,FBS)的DMEM/F12培养基进行培养。添加碱性成纤维生长因子(bFGF)进行细胞培养,培养瓶置于37℃、饱和湿度体积分数为5%CO_2培养箱中培养,3d后全量换液,去除未贴壁细胞,每3～5d全量换液。待细胞长至80%～90%融合,按1:2的比例以1×10~6cells/ml密度接种进行传代培养。取第4～6代羊膜MSCs用流式细胞仪检测MSCs的免疫表型CD29,CD44,HLA-ABC的表达。取第3代的羊膜MSCs,用20μg/L bFGF和30μmol/L全反式维甲酸(Retinoic acid,RA)诱导培养的细胞向神经细胞分化。于诱导前及诱导后8d、13d分别进行神经巢蛋白(neuroepithelial stem cell protein,nestin)神经元特异性烯醇化酶(neuron specific enolase,NSE)和胶质纤维酸性蛋白(glial fibrillary acidicProtein,GFAP)免疫细胞化学染色。
 第二,量子点神经生长因子纳米粒(QDs-NGF-NPs)、Fe_3O_4纳米颗粒(菲力磁)标记羊膜MSCs及诱导分化
 待第三代羊膜间充质干细胞达到80%～90%融合时用2.5g/L胰酶消化,接种于96孔培养板上,每孔200μl,将制好的小玻片置于培养板,待细胞爬满小玻片后,培养基中分别加入不同浓度Fe_3O_4纳米颗粒及QDs-NGF-NPs,Fe_3O_4纳米颗粒标记组分为对照组及实验组,对照组为不含铁纳米颗粒培养基培养的羊膜MSCs,实验组分为四组,使Fe_3O_4纳米颗粒终浓度分别为20μg/ml、30μg/ml、40μg/ml和80μg/ml。每组均加入转染剂多聚左旋赖氨酸,使其终浓度为1.5μg/ml。细胞培养24h均更换为正常培养基,继续培养3周。于细胞培养12h、36h、1周和3周进行普鲁士蓝染色。QDs-NGF-NPs标记组分为实验组及对照组,对照组分为空白对照(培养基中加入等量生理盐水)及单纯量子点对照(培养基中加入终浓度为20、40和60μg/L的量子点)。实验组为QDs-NGF-NPs组,培养基中加入量子点使其终浓度分别为20、40和60μg/L。
 根据以上两组实验结果设计QDs-NGF-NPs及Fe_3O_4纳米颗粒联合标记组。该组分为实验组及对照组。QDs-NGF-NPs及Fe_3O_4纳米颗粒组按每孔量子点的终浓度分设3个浓度亚组(20、40、60μg/L)及相应Fe_3O_4纳米颗粒的终浓度为20μg/ml、30μg/ml和80μg/ml,加入多聚左旋赖氨酸终浓度为1.5μg/ml。空载量子点组(不含神经生长因子纳米颗粒)按上述相应量子点浓度分为三组作为对照,正常对照组不加量子点及Fe_3O_4纳米颗粒。培养24h后,更换培养基为正常培养液,继续培养24h、48h、72h后,每孔加入20ul(5g/L)MTT溶液,继续孵育4h后,弃上清,加入100ulDMSO终止反应。微震荡后,于酶标仪波长490nm处测得吸光度值(A)。正常对照组细胞存活率记为100%,其余各组细胞存活率按公式计算:细胞存活率=(实验组A值/对照组A值)×100%,即吸光值越大,存活率越高。置于荧光显微镜下观察量子点在细胞内的分布。分别与12h、36h、1周和3周普鲁士蓝染色,观察Fe_3O_4纳米颗粒进入细胞情况。
 细胞分化鉴定:对QDs-NGF-NPs标记组及QDs-NGF-NPs、Fe_3O_4纳米颗粒共标记组用20μg/L bFGF和30μmol/L全反式维甲酸(Retinic acid,RA)诱导羊膜MSCs向神经细胞分化,诱导后第8d及13d用4%多聚甲醛固定30 min,PBS洗涤,加入过氧化物酶阻断液阻断内源性过氧化物酶,非免疫性动物血清封闭,分别加入小鼠抗人神经元烯醇化酶(NSE)、神经巢蛋白(nestin)和胶质纤维酸性蛋白(GFAP)单克隆抗体(即用型1:100稀释),室温孵育1h,PBS洗涤,加入生物素标记的二抗,室温下孵育10min,洗涤,加入链亲和素-过氧化物酶溶液,孵育10min,洗涤,DAB溶液显色,中性树胶封固。
 第三,脑损伤模型的制作及不同移植途径的疗效探讨将80只Wistar大鼠,采用自由落体硬膜外撞击法制作大鼠脑创伤模型,损伤装置由底板、固定支架、垂直导杆、20 g砝码、聚乙烯撞击圆锥组成。撞击圆锥头端直径4mm,高2.5mm。10%水合氯醛腹腔注射(3ml/kg)麻醉大鼠后,将头部固定于立体定向仪上,剪去顶部皮毛,消毒,沿中线切开皮肤及骨膜,左侧前囟后3mm,左旁开2mm,钻一直径为5mm的圆形窗,砝码自30cm高处垂直落下,撞击置于硬膜上的圆锥,致中度脑损伤,缝合骨膜及皮肤。大鼠脑外伤模型随机分为对照组与治疗组,对照组20只,治疗组60只,分三组,每组20只,分别标记为A组尾静脉移植组,B组侧脑室移植组及C组脑损伤区移植组。应用平衡木行走试验进行神经功能评分评估大鼠神经功能损伤程度。各组动物分别于1d、4d、1w、2w、3w时处死4只,进行NSE、nestin和GFAP免疫组织化学荧光染色检测,了解移植后的羊膜间充质干细胞的存活、迁移和分化等。根据实验结果选定合适移植途径。
 第四,羊膜间充质干细胞移植、活体示踪、神经行为学评分、免疫组化检测实验分为实验组及对照组,对照组20只脑损伤动物模型,相同浓度的菲力磁生理盐水代替羊膜MSCs植入脑损伤区,实验组分为AB两组,共40只大鼠模型,每组20只。A组由第三代羊膜MSCs原位移植于脑损伤区,B组由第三代羊膜MSCs经QDs-NGF-NPs及菲力磁标记24h后原位移植入脑损伤区,在脑损伤区域及其边缘注射含羊膜间充质干细胞的生理盐水10μl(细胞浓度为2.0×10~7/μl),每点进针3mm,针头在注射部位保留5min,然后拔出针头,骨蜡封闭骨窗,缝合骨膜,皮肤。细胞移植后当天记为0d,在移植后的0d,1d,7d,14d,21d进行3.0T核磁共振仪扫描,观察羊膜MSCs的存活迁移情况。成像条件:MRI采用SIEMEMS 3.0 Trio TimⅠ-class MR扫描仪和眼表面线圈,行横断面及冠状面TSE:T1WI、T2WI,T2*WI及SWI序列扫描,扫描参数为:T1WI:TR/TE=430/12ms,T2WI:TR/TE=5990/98ms,层厚2.0mm,FOV10cm×10cm,矩阵288×224;T2*WI:TR/TE=500/20ms,层厚2.0mm,翻转角20°,矩阵256×256;SWI:TR/TE=29/20ms,层厚0.6mm,FOV6cm×6cm,翻转角15°,矩阵256×256。动物模型建立后定时进行神经功能评分。在模型建立后的7d、14d、21d时分别处死动物,进行普鲁士蓝染色了解铁纳米颗粒的存在情况,免疫组织化学荧光法检测神经巢蛋白(nestin)、神经元特异性烯醇化酶(NSE)和胶质纤维酸性蛋白(GFAP)表达情况。
 第五,安全性检测在动物模型建立前、后2w及3w对各组动物尾静脉埋植细针头累积抽血0.5ml,抽血前静脉注入肝素(15U/kg)全身肝素化,对样本进行血常规及12项肿瘤标志物联合检测,观察评估经QDs-NGF-NPs及菲力磁标记的羊膜间充质干细胞移植治疗脑损伤大鼠的安全性。
 结果:
 经酶消化法自人羊膜组织中提取到的细胞混悬液,置于培养瓶中体外培养,观察到部分细胞最早于10h左右开始贴壁,继续培养1d～2d时,贴壁细胞逐渐增多,培养至1w时,细胞贴满瓶底,细胞形态大多为长梭形,部分为多角形及不规则形状,总体显示为梭形细胞,类似于成纤维细胞的形态。给于消化全量换液传代后,细胞生长加快,在3～6d内铺满瓶底,细胞部分发生融合,细胞以长梭形为主,呈索条状或螺旋状分布。第3～4代的细胞增殖活性较强,一般传代后3d左右可以铺满瓶底,传代至第6～8代后,细胞形态开始出现老化现象,呈扁平状,增殖缓慢或者停止增殖,培养至第9～10代以后,上述现象更加明显。
 取第3～4代细胞进行流式细胞术检测,结果显示自人羊膜组织中提取的细胞表达抗原CD29,抗原CD44及抗原HLA-ABC。与间充质干细胞表面抗原一致,提示所得细胞为间充质干细胞。羊膜间充质干细胞体外培养条件下,给与20μg/L bFGF和30μmol/L全反式维甲酸(Retinoic acid,RA)联合诱导后,可以检测到细胞nestin及NSE的表达,提示人羊膜间充质干细胞转化为神经元样细胞。
 应用菲立磁标记的羊膜MSCs普鲁士兰染色结果显示,终浓度为20μg/L的Fe_3O_4纳米颗粒组细胞标记率为60%,30,40,80μg/L的Fe_3O_4纳米颗粒细胞标记率均为100%。Fe_3O_4纳米颗粒浓度大者同期进入细胞的铁颗粒就多,36h时各浓度组细胞内铁颗粒聚集达高峰。1w及3w时细胞内铁颗粒逐渐减少。光镜下可以看到细胞内蓝染的铁颗粒分散在胞浆中。
 应用QDs-NGF-NPs(浓度小于40μg/L)标记组及QDs-NGF-NPs(浓度小于40μg/L)、菲力磁(浓度小于30μg/ml)联合标记组的培养基培养羊膜MSCs6h后,荧光显微镜下均可见羊膜MSCs的胞膜及胞浆中有红色荧光发出,随时间延长进入细胞的量子点逐渐增多,于32h荧光强度达到高峰,2周内量子点荧光强度未见减弱。普鲁士兰染色见QDs-NGF-NPs(浓度小于40μg/L)、菲力磁(浓度小于30μg/ml)联合标记组羊膜MSCs的胞浆中有大量蓝染的铁颗粒存在,经诱导后两组细胞均有部分细胞表达神经元特异性烯醇化酶(NSE),部分细胞表达神经巢蛋白(nestin),未检测到胶质纤维酸性蛋白(GFAP)的表达。
 在移植后第1d开始,钉板平衡木行走测试,评分在对照组5.42±0.98、A组(尾静脉移植)5.02±1.98、B组(侧脑室移植)5.54±1.34和C组(脑损伤区移植)5.12±1.04,各组相比无统计学差异(P＞0.05)。移植后第7d评分对照组5.11±1.62、A组5.15±1.02、B组5.51±2.04和C组4.55±1.02,C组与对照组、A组及B组比较统计学有差异(P＜0.05)。其它各组之间统计学差异不明显(P＞0.05)。在术后13d进行评分显示,对照组5.11±1.92、A组5.01±0.92、B组4.86±0.87和C组2.66±1.72,C组与其它各组比较有统计学差异(P＜0.05),B组与A组及对照组相比有统计学意义(P＜0.05)。A组与对照组相比无统计学差异(P＞0.05)。饲养至第3周时各组评分均未见进一步变化。侧脑室注射羊膜间充质干细胞组显示损伤区表达NSE和nestin的细胞较少,侧脑室壁显示有少量NSE和nestin表达。大鼠脑损伤区定点注射羊膜间充质干细胞组,可见损伤区附近有较多细胞表达NSE和nestin,提示植入的羊膜间充质干细胞部分种植、存活。大鼠尾静脉注射组,在脑损伤区局部组织中未检测到NSE和nestin表达。
 菲力磁标记的MSCs脑内移植后对照组及实验组B组在0d扫描时显示T1、T2、T2*GRE扫描在移植区可见低信号区。其中T2*GRE扫描最敏感。在1d,7d,14d,21dMR扫描时,对照组不显影,实验组显示T1、T2、T2*GRE扫描在移植区可见低信号区。其中T2*GRE扫描最敏感。在14d及21d扫描显示在细胞植入区仍能清晰观察到低信号区,向周围弥散现象不明显。A组在MR扫描时不显影。神经功能评分显示细胞移植后的前4d,各组评分统计学没有明显差异,在细胞移植第4d后A组B组评分开始低于对照组,统计学有意义,B组与A组相比统计学有差异,至14d左右,评分没有更进一步变化。普鲁士兰染色结果显示,在移植针道附近可见蓝染的铁颗粒存在,随时间延长,蓝染程度下降,在针道附近蓝色有弥散趋势。免疫组织化学荧光染色显示对照组没有检测到神经巢蛋白(nestin)神经元特异性烯醇化酶(NSE)和胶质纤维酸性蛋白(GFAP)的表达,实验组两组均有不同数量的细胞表达神经巢蛋白(nestin)及神经元特异性烯醇化酶(NSE),未检测到胶质纤维酸性蛋白(GFAP)的表达。B组神经巢蛋白(nestin)及神经元特异性烯醇化酶(NSE)表达明显多于A组(p＜0.05)。
 在动物模型建立前及后2w、3w时抽血,进行血常规及12项肿瘤标志物联合检测,结果显示血常规及12项肿瘤标志物未见异常。
 结论:
 酶消化法能够从人羊膜组织中分离提取出MSCs,经bFGF和全反式维甲酸体外诱导,能够分化为神经元样细胞,证实人羊膜MSCs具有多分化潜能。
 量子点神经生长因子纳米颗粒(QDs-NGF-NPs)及菲力磁可以在体外成功标记羊膜MSCs,浓度小于40μg/L的QDs-NGF-NPs及浓度小于30μg/ml的菲力磁对羊膜MSCs的生长分化没有影响。
 脑损伤区移植羊膜间充质干细胞较尾静脉及侧脑室移植能更大程度改善大鼠的神经功能。
 神经生长因子纳米化颗粒能有效进入羊膜MSCs,经脑损伤区原位移植能有效改善脑损伤大鼠的神经功能。
 羊膜MSCs经菲立磁标记移植大鼠后,能够在脑损伤区存活分化,借助3.0T核磁共振仪能有效观察到羊膜MSCs移植后的存活情况。
 经QDs-NGF-NPs及菲力磁标记的羊膜MSCs移植治疗脑损伤大鼠,观察3w检测大鼠血常规及各项肿瘤标志物均未见异常,提示该方法安全。
学位年度:2009

Multi-ferrous composite materials, power, electricity, magnetic coupling mechanism and properties

　　Title: Multi-ferrous composite materials, power, electricity, magnetic coupling mechanism and properties of
　　Author: Lu Xiaoyan
　　Degree-granting unit: Harbin Institute of Technology
　　Keywords: complex multiple-ferrous;; Ginzburg-Landau theory;; dielectric constant;; bending properties;; energy release density
　　Abstract:
　　Multi-iron material is a class of ferroelectric, ferromagnetic and ferroelastic coupling between the two or more properties of both materials, this material
　　Under external electric field can induce magnetic polarization, the outer magnetic field can induce electric polarization, with the effect of Neodymium Magnets magnetic coupling product performance. This strange
　　Special performance for the materials and devices designed to increase the degree of freedom, in a multi-site information storage and read-write, wireless microwave devices, wireless sensor networks
　　Network and multi-functional electronic devices have great potential applications, has become a hot research field of functional materials.
　　With multiple Railway of
　　Single type of substance and material in nature, very few, and most at very low temperatures have a strong magnetic coupling effect, and the use of ferroelectric
　　Scalability and electroluminescent materials the magnetostriction of the magnetic elastic coupling through the interface between the compound prepared in multi-material iron
　　Room temperature with a large magnetic coupling. Because of this magnetic coupling mainly from the elastic coupling between the two phases, and therefore, analysis of two
　　Phase interface between the film and substrate interface interaction between the elastic carefully consider the external electric field and external magnetic field on the stress field within the material
　　Influence each other in order to match a reasonable choice of material, greater magnetic coupling properties. In this paper, a composite http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets of multiple materials of iron
　　Coupling mechanism, detailed consideration of the size effect, surface effect, volume copies, thickness, and a variety of stress and strain on the material properties,
　　Also concerned about how to use some of the features of this coupling performance structural materials to achieve more than many degrees of freedom control, and finally, the fracture of materials
　　Done a preliminary analysis of the performance. The following are the main research paper ideas, methods and conclusions:
　　1) Based on Landau theory, detailed
　　Analysis of the 1-3 type ferroelectric ferromagnetic nano-composite materials in a variety of stress-strain relationship and interaction between the free energy of the system
　　. Include a variety of stress-strain ferroelectric phase electrostrictive strain and strain and magnetostriction ferromagnetic phase between the two phases and films and linings
　　Since the end of the lattice mismatch between the mismatch stress and dislocation resulting from the release because the stress between the elastic interaction. The establishment of the electrode
　　And magnetic polarization of the time evolution of the Ginzburg - Landau equation dynamics, bifurcation theory predicted by two-phase materials, the phase transition point, the use of numerical
　　Method gives the steady state polarization and magnetic pole strength of the two phases of strength and strain state, and based on the Landau-Khalatnikor side
　　Method, numerical simulation of the coupling field intensity under the electrode and pole of the intensity of the butterfly curve;
　　2) based on Ginzburg-Landau
　　Elasticity theory with Timeshenko method of dielectric / magnetic alloy (Ba0.6Sr0.4TiO3/terfenol-D) layered composites
　　Dielectric properties studied. The use of an external magnetic field-induced magnetic alloy magnetostriction can be adjusted within a certain range of small barium strontium titanate
　　Field dielectric properties, and by changing the Ba / Sr composition ratio and thickness greater than can be achieved within the scope of regulation;
　　3) the use of magnetic coupling
　　Effect, the design of ferroelectric / ferromagnetic layered bent-type drive, and use the method of Hsueh ferroelectric / magnetic alloy laminated composite curved
　　Performance studies. The results show that the magnetic field control terfenol-D magnetostrictive layer can control the vertical structure of the relative bending
　　Move up to 55%;
　　4) energy-based approach, from a macro-scale study of ferromagnetic ferroelectric fiber reinforced matrix composite knot
　　Structure of the fracture toughness. Consider the power, electricity and magnetism more than the magnetic coupling effect of the performance obtained on the ferroelectric polarization and magnetic pole of strength
　　Intensity of energy release density function. Structure is heavily dependent on the fracture toughness of ferroelectric materials and the size of the polarization of ferromagnetic materials, two
　　Phase composition and interface flexibility than the interaction.
　　Degree Year: 2009

食激变变星的测光分析

题名:食激变变星的测光分析
作者:戴智斌
学位授予单位:中国科学院研究生院（云南天文台）
关键词:激变变星;;双星物质交流;;磁滞;;演化;;类太阳磁活动;;光时效应;;棕矮星
摘要:
 激变变星(CVs)是一类相互作用的半相接型密近双星系统,由一颗充满洛希瓣的(K/G/M型)
主序矮星或巨星和一颗演化后的白矮星组成。在物质从充满洛希瓣的矮星流向白矮星的过程中,物
质流因带有强大的角动量围绕着白Magnetic lifter矮星运动而无法马上落入白矮星表面,并且彼此之间因粘滞摩擦
逐渐消耗角动量而延展形成盘状。这样进入主星洛希瓣的物质流与盘相互碰撞形成了高温高光度的
碰撞区域——亮斑。于是,白矮星、吸积盘、亮斑和红矮星就构成了激变变星的基本物理图像。除
了偏振星(激变变星的一个磁亚型)以外,几乎所有激变变星的各种观测特征都来自于这个系统内部
各成分之间的物理过程和相互作用。在近二十年的激变变星研究领域,轨道周期变化方面的研究工
作被长期忽视,主要是由于早期的测光精度不够高,同时激变变星本身比较暗弱且存在大量不规则光
变,因此人们在观测上不易获得有价值的数据和重要的研究结果。另一方面,在分光方面的研究也不
尽如人意,这是因为激变变星是个含有多光源成分且彼此层次模糊的天体系统,这导致光谱的混叠、
偏移和展宽都十分严重而http://www.999magnet.com/products/131-magnetic-lifter无法获取准确的谱线信息和视向速度曲线。因此,目前要在激变变星领域
完成有一定价值的科学研究,无论是测光还是分光都需要有高精度的数据。于是,本篇博士论文立足
于国内观测仪器现状,从测光的角度对激变变星中带有掩食的目标进行轨道周期变化分析研究。首
先,通过对带有掩食的激变变星进行大量的调研和统计工作,一个较完整的108颗食激变变星星表被
获得。其次,以此为基础,对十颗具有代表性特征的食激变变星(新星DQ Her和T Aur,矮新星UGem、Z
Cha和V2051 Oph,类新星AC Cnc、V363 Aur、RW Tri、SW Sex和UUAqr)进行了重点监测和分析研究
。同时,为了更好的开展对激变变星的研究,本篇论文还对带有掩食的激变变星前身星进行详细的调
研,并对其中一颗重要的激变变星前身星HW Vir的轨道周期变化和绝对参量进行系统的研究。从这
十一颗样本星的分析和早期的统计研究工作中,我们取得了以下三个重要的研究成果:
 1.通过
对SW Sex和UU Aqr这两颗处于轨道周期空缺上边缘3h≤P≤4.5h的SW Sex型激变变星进行轨道周期
变化分析研究,我们发现二者的轨道周期是长期增加的。再对处于该周期范围的非SW Sex型激变变
星DQ Her和U Gem进行轨道周期变化分析研究也发现具有轨道周期的长期增加。虽然后两颗星的轨
道周期增加也可以用其他并不成熟的物理机制(如:新星爆发和低倾角系统的热斑运动)来解释,但是
它们还是被认为应该是和SW Sex类型的激变变星一样体现出系统内部的强化物质交流过程,而与中
断磁滞演化理论要求的向轨道周期减小方向演化不符。这为后续的研究做了一个很好的铺垫工
作。
 2.我们对激变变星前身星HW Vir,处于3h≤P≤4.5h范围之外的类新星AC Cnc、V363 Aur和
RW Tri,以及极短轨道周期的矮新星V2051 Oph这五颗几乎覆盖整个激变变星演化链的样本星进行详
细的轨道周期变化研究,并发现这五颗星都无一例外的展示出轨道周期长期减小的趋势。另外,这五
颗星都因质量比q≤1而必须要引入有效的轨道角动量损失机制,如:引力辐射或磁滞。这个轨道周期
变化分析的结论似乎与中断磁滞演化理论一致,但是,很遗憾的是在对短周期样本星HW Vir和V2051
Oph进行详细的轨道角动量损失机制讨论时发现引力辐射能提供的损失作用远没有达到观测的轨道
周期减小率。这意味着中断磁滞演化理论预言的极短轨道周期的激变变星应该仅由引力辐射来驱使
演化可能是不正确的。考虑到引力辐射机制的解释失败,我们重新将磁滞机制应用在这些目标中发
现磁滞能够对观测的轨道周期减小率给出一个很好的解释。至此,中断磁滞演化理论提出的磁滞必
须在轨道周期达P～3h时因伴星转变为全对流而同时中断的假设是很难站住脚的。考虑到近年来其
他有关全对流恒星的磁场及星风的研究工作和我们在3h≤P≤4.5h范围发现观测与理论不符的结论(
第一点的研究工作),我们认为磁滞应该很自然的穿过轨道周期空缺而不会产生任何中断。从最新的
轨道周期分布图中可以看出轨道周期空缺现象正在慢慢弱化,因此,如果轨道周期空缺确实消失的话
,那么磁滞作用可以自然的通过这个禁区并且在激变变星演化晚期因伴星转变为低质量的棕矮星而
最终消失。这也是对激变变星中最短轨道周期截止现象给出一个自然的解释。
 3.在对这十一颗
样本星进行轨道周期变化分析时,我们发现有九颗星的O-C图具有周期性振荡变化。于是,两个最有
可能的机制——Applegate机制(磁活动)和光时效应被详细的讨论。由于磁活动机制在所有的九颗
包含周期性振荡成分的样本星中都遭遇到严重的能量不足问题,因此,我们认为对于激变变星O-C图
的周期性振荡来说光时效应可能会是更好的一个解释。以此为基础,大量的棕矮星甚至大质量地外
行星在激变变星环境中被发现。考虑到激变变星都是低质量双星系统,我们可以预测未来的激变变
星轨道周期变化分析工作应该会找到更多类似棕矮星等的暗弱天体。
学位年度:2009

插入件积分场测量装置研制及相关技术研究

题名:插入件积分场测量装置研制及相关技术研究
作者:汪涛
学位授予单位:中国科学技术大学
关键词:插入件;;波荡器;;磁场一次积分;;磁场二次积分;;位相误差;;磁场测量;;单磁块测量;;亥
姆霍兹线圈;;磁块排布优化;;模拟退火法;;悬线法磁场测量;;脉冲线磁场测量;;磁场调整;;磁场垫
补;;椭圆极化波荡器;;APPLE-II型波荡器
摘要:
 插入件是应用于同步辐射光源和自由电子激光装置的关键设备,而插入件磁场测量则是插
入件磁场性能参数的调试、检验,达到Magnetic lifter品质要求的必要手段。插入件磁场测量指标多,数据量大,反
映磁场性能的参数包括峰值场强误差,磁场一次积分,二次积分以及位相误差等等,而且需要反复调
整测量。磁场测量工作量大,对精度与速度要求都很高。
 本论文的工作分为两部分,主要部
分是悬线法积分场快速测量装置的研制和脉冲线积分场快速测量装置的研制以及装置的实际应用;
另外一部分是插入件磁场相关技术研究,包括上海深紫外自由电子激光波荡器系统全部磁化块的测
量、磁块的筛选和用模拟退火法进行磁块排列组合优化以及对APPLE-II型椭圆极化波荡器磁场横向
均匀性改进的探索。
 第一章绪论简述了插入件的历史和分类,介绍了插入件磁场技术和各种
磁场测量方法;第二章给出了悬线法积分场测量系统的研制,包括硬件结构和控制程序编写,讨论并
分析了测量误差的主要来源,并描述了利用该系统测量垫补上海深紫外自由电子激光器其中一台波
荡器的详细过程;第三章主要讲述脉冲线积分场测量系统研制过程,讨论分析了影响脉冲线测量精度
的各种因素,优化了装置各部分设计,给出了脉冲线和霍尔点测磁场测量结果的对比,最后利用该系
统测量了实验室即将投入http://www.999magnet.com/products/131-magnetic-lifter使用的电磁型椭圆极化波荡器;第四章测量上海深紫外自由电子激光波荡
器全部单磁块的磁化强度,在此基础上对磁块进行了筛选以及用模拟退火法完成了磁块的排列组合
优化,对按照优化组合装配好的其中一台波荡器进行了测量调整;第五章是对尝试改进APPLE-II型波
荡器磁场横向均匀性的一些方案的模拟计算。
学位年度:2009

HT-7托卡马克芯部温度涨落与锯齿磁重联的电子回旋辐射成像诊断研究

题名:HT-7托卡马克芯部温度涨落与锯齿磁重联的电子回旋辐射成像诊断研究
作者:徐小圆
学位授予单位:中国科学技术大学
关键词:中国科学技术大学:5289,磁重联:4174,托卡马克装置:3594,等离子体:3020,锯齿:2950,博
士学位论文:2787,电子温度:2309,高阶模:1991,湍流:1895,温度梯度:1784
摘要:
 我们利用在HT-7托卡马克装置上建立的一套新颖的高时空分辨的电子温度诊断设备:二维
电子回旋辐射成像(2D ECEI)系统,用二维Neodymium Magnets成像的方法系统观测了纯欧姆托卡马克芯部等离子体中电
子温度湍流不稳定性和锯齿MHD不稳定性引起的磁重联。
 我们在纯欧姆等离子体芯部的电子
温度涨落的研究方面主要有如下结果。在低密度条件下的,芯部湍流的宽带电子温度涨落具有电子
漂移波湍流的特征:在电子逆磁漂移方向传播,波数kθρs～0.34 ,温度梯度符合混合标长估计。同
类型的TEXT-U托卡马克上的芯部湍流相对幅度有1%,而我们的湍流谱的幅度仅有0.5%甚至更弱,观测
并分析到湍流的结果是很难得的。但是,当密度非常高时,这支单方向传播的电子模,在等离子体某
些区域演变为双模:一支在电子逆磁方向,另一支在离子逆磁方向。这两支模应当分别是TEM模和ITG
模。通过对芯部电子温度涨落的二维测量,我们发现了芯部涨落不均匀分布的普适特性。我们还发
现,在宽带电子温度湍流中存在低频带状流(Zonal Flow)的迹象。
 我们对锯齿MHD不稳定性
做了系统的研究。目前,为了解释复杂的MHD锯齿振荡不稳定性实验现象,对于锯齿磁重联过程,理论
研究中提出了多种重联模型http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets,其中,有Kadomtsev模型,Wesson模型,气球模3-D模型,和Porcelli模型
等,关于重联机理,有气球模的压强梯度和Lichtenberg的磁场随机不稳定性。ECEI诊断方法无需借
助刚体旋转假设,能够比较真实反映了磁重联过程,为验证理论模型和深入揭示锯齿磁重联机制,提
供了一个重要的手段。我们在HT-7托卡马克装置上,应用ECEI系统进行的实验观测,给出了清晰的二
维重联过程。该结果基本符合Kadomtsev模型的图像,而和Wesson模型的图像不一致,符合气球模在
低场侧的模型;该结果表明重联机理,倾向于气球模的压强梯度不稳定性,但和气球模在高场侧的结
果不一致,但还不能完全排除磁场随机不稳定性的影响。其次,我们利用二维成像还观测到在q～1面
附近,存在高阶模(极向模数m > 1)的多磁岛结构,以及由它们直接导致的q=1面上多点重联现象。这
是一种理论模型还没有深入研究过的新现象。我们研究了不同密度和qa值条件下,高阶模,重联点,
以及边界磁信号的特征和关系。对于不同的qa存在一个密度阈值,当密度超过这个阈值后,高阶模会
显著的减小,m/n=1/1模代替它成为主导。这个阈值随着qa增加而减小。中心的1/1模和边界磁信号
3/1模也是相关的。最后,我们还发现了前兆时间非常短暂的锯齿。这种锯齿主要在大托卡马克中观
察到,破裂时间远小于Kadomtsev特征时间。
学位年度:2009

基于磁流变半主动悬架的汽车底盘集成控制

题名:基于磁流变半主动悬架的汽车底盘集成控制
作者:祝辉
学位授予单位:合肥工业大学
关键词:汽车底盘;;磁流变液;;半主动悬架;;集成控制;;相互影响;;实车试验
摘要:
 随着国民经济的飞速发展以及人们生活水平的极大提高,汽车逐渐融入到人们的工作生活
之中,成为不可或缺的交通工具。随之而来的汽车行驶速度的显著提高和道路行车密度的急剧增大,
使得人们对汽车的行驶平顺性、操纵稳Neodymium Magnets定性和安全性提出更高的要求。而电子技术和自动化技术的
发展,使越来越多的控制系统运用到汽车当中。其中,电控悬架作为连接车身和底盘的一个桥梁,在
汽车底盘控制中起着至关重要的作用。磁流变半主动悬架具有响应快、动态范围宽、功耗低、结构
简单等特点,是目前电控悬架的研究热点,在商业和军事上都具有广阔的应用前景。目前,国内外对
磁流变半主动悬架的研究多处于理论研究和实验室研究中,实际应用在整车上并不多见,主要原因是
磁流变半主动悬架是一个存在有不确定因索、时滞的复杂非线性系统,使得控制策略的设计和实现
极具挑战性,先前的一些半主动控制算法针对具体问题的特征,虽然都取得了一定的控制效果,但仍
然存在局限性,较少从整车的角度对http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets悬架进行控制。因此,如果以磁流变半主动悬架为核心,考虑整
车多个子系统之间的相互影响,以整车的综合性能为目标进行协调控制,具有很高的研究价值。自20
世纪80年代中期至今,企业界和学术界从理论和应用方面对车辆动力学中多子系统之间的协调控制
问题进行了大量的研究。对协调控制的研究中,一般是对两个系统进行研究且设计一个控制器,而考
虑汽车底盘多个子系统之间的相互影响并进行协调控制的研究较少。
 本文以磁流变半主动悬架
为核心,分析汽车底盘中悬架、转向和制动系统运动之间的耦合关系和相互影响,设计出半主动悬架
和主动前轮转向的协调控制器,以及半主动悬架、制动防抱死和直接横摆力矩控制的协调控制器。
主要包括以下内容:
 (1)首先回顾了汽车动力学的研究进展以及汽车底盘主动控制的研究现
状。随后分析了汽车底盘集成控制的研究现状及存在的问题,最后给出了本文的研究内容和创新点
。
 (2)建立考虑相互影响的汽车悬架、转向和制动系统的数学模型以及轮胎模型。在
MATLAB/SIMULINK中搭建了整车的模型,并对不同工况下的各种运动之间的相互影响和制约关系进行
了理论分析和仿真计算。
 (3)设计了一款剪切和流动混合工作模式的磁流变减振器,给出了磁流变
减振器的数学模型,对所设计的减振器进行了台架试验,并将其安装于改装车上。根据磁流变半主动
悬架本身具有不确定性、时滞性强等特点,设计了参数自调整PID控制器,进行了脉冲输入和随即路
面输入的整车仿真试验。以ARM单片机LPC2292为核心,完成了电荷放大器、车速信号调理、恒流源
驱动及系统故障诊断等电路的设计。引入了嵌入式实时操作系统μC/OS-Ⅱ,并成功移植了控制算法
。将磁流变半主动悬架应用于试验车上,进行了台架试验和道路试验。
 (4)对基于7自由度整车模
型的半主动悬架设计了最优控制器,运用分离定理,得到随机状态反馈调节器的最优控制率。为改善
整车的操纵稳定性,对主动前轮转向系统设计了可实时跟踪目标横摆角速度的滑模变结构控制器。
为改善转向工况下车辆的行驶平顺性,在两个子系统的基础上设计了一个上层协调控制器。协调控
制器根据车辆传感器信息,实时地调整转向和悬架子系统跟踪目标和控制参数,以使车辆获得最好的
性能。仿真结果表明:所设计的控制器能够较好的提高整车的行驶平顺性和操纵稳定性。
 (5)为
改善车辆的行驶平顺性、操纵稳定性和安全性,对悬架、转向和制动系统分别设计参数自调整PID、
滑模变结构和变滑移率逻辑门限值控制器,采用状态识别模式的协调控制方法,进行了多种行驶工况
下的整车控制系统仿真。
 (6)基于ARM7平台,进行了制动防抱死系统和半主动悬架系统协调控制器
的开发,并进行了实车试验。
 (7)总结了全文的研究内容,对下一步的研究提出一些建议。
学位年度:2009

FeCo-B_2O_3纳米颗粒膜的高频软磁性及其各向异性调制

题名:FeCo-B_2O_3纳米颗粒膜的高频软磁性及其各向异性调制
作者:肖玉华
学位授予单位:兰州大学
关键词:各向异性场:4270,软磁材料:3770,颗粒膜:3674,矫顽力:3147,体积分数:3112,软磁性能:2784,典型样品:2627,高磁导率:2608,共振频率:2558,高饱和磁化强度:2536
摘要:

 随着电磁器件微型化、集成化和高频化的不断发展,对软磁材料提出了更高的要求。软磁材料必须具有高磁导率μ、高饱和磁化强度M_s、高电阻率ρ和适当大的各向异性场H_k,以便有效降低涡流损耗、提高截止频率。金属—绝缘体纳Neodymium Magnets米颗粒膜是一种新型的软磁材料,它将金属材料的高磁导率μ和绝缘体材料的高电阻率ρ集为一身,使得在一种材料中同时具有高磁导率和高电阻率成为可能,因此近年来这类颗粒膜材料已经成为软磁材料研究领域的热点之一。而颗粒膜的各向异性调制对拓展其工作频率是极其重要的。

 本文中,我们采用射频磁控溅射方法制备了FeCo-B_2O_3系列纳米软磁颗粒膜。利用X-ray衍射和HRTEM得到了样品的微观结构信息;用VSM和直流四端法等系统地研究了样品的磁性和电性;利用短路微扰传输线法测量了样品的高频特性;初步探讨了颗粒膜的各向异性场的调制方法;主要得出以下结论:

 一、结构

 利用射频磁控溅射方法成功制备了(Fe_(65)CO_(35))_x-(B_2O_3)_(1-x)系列颗粒膜。HRTEM明场像显示样品由纳米级(1～8 nm)的磁性金属颗粒均匀地镶嵌在B_2O_3绝缘介质中构成,其金属颗粒尺寸随金属体积分数的减小而减小。电子衍射环证明磁性金属颗粒为体心立方晶体结构。另外,X-ray衍射和HRTEM研究表明样品的晶粒尺寸基本等于颗粒尺寸,这说明一个颗粒只包含一个晶粒。

 二、磁性

 (1)系统地研究了(Fe_(65)Co_(35))_x-(B_2O_3)_(1-x)颗粒膜系统的矫顽力H_c随磁性颗粒体积分数x的变化关系。在x=0.66-0.55的成分范围内,得到了好的软磁性能。矫顽力H_(ce)最小为13.4Oe,最大不超过15.6Oe。我们认为,好的软磁性是由铁磁颗粒间的交换耦合所致。对于(Fe_(65)Co_(35))_x-(B_2O_3)_(1-x)系统,由于Fe_(65)Co_(35)的铁磁性交换长度L_(ex)较大(～26.0nm),使得颗粒大小D和间距S之和都远小于L_(ex),从而在该成份范围内,颗粒间会发生交换耦合。由于交换耦合使颗粒http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets的磁矩趋向平行排列,从而平均了单个颗粒的磁晶各向异性,并克服了退磁效应,使得样品的平均各向异性显著降低,因此有效地地降低了矫顽力。

 (2)研究了磁各向异性场H_k随x的变化。结果表明随着x的减小,样品的H_k与H_c的变化趋势相反,先增大后减小,在0.55＜x＜0.66范围内H_k较大并且在x=0.61时,H_k最大达到65Oe;说明在交换耦合比较强的区域,H_k有较大的值。

 (3)δM(H)曲线的研究结果表明:(Fe_(65)Co_(35))_x-(B_2O_3)_(1-x)系统颗粒间的相互作用为类铁磁性的相互作用,即交换耦合,它导致了低的矫顽力和高的磁导率。

 三、高频特性

 利用短路微扰传输线法测量了Fe_(65)Co_(35)-B_2O_3系统样品的高频特性。

 (1)在0.55＜x＜0.66的范围内,获得了很好的高频性质,具有高的磁导率μ′和铁磁共振频率f_r;并且在这一范围内样品具有很高的电阻率ρ,颗粒薄膜的这些性质预示着这种样品具有很好的高频应用前景。

 (2)对于x=0.61的Fe_(65)Co_(35)-B_2O_3典型样品,在f＜1.3GHz时,实部μ′大于180,而虚部μ″在f＜1.0 GHz范围内小于50。当频率大于1.0 GHz时,μ″迅速增大,这是由于铁磁共振(FMR)所致,且共振频率高达2.65 GHz,电阻率高达2.38×10~3μΩ·cm,较纯金属的高三个量级。用Landau-Lifshitz方程拟合的结果表明在此甚高频下磁性行为是自然共振。

 四、FeCo-B_2O_3系统的各向异性调制

 本文采用以下两种方式研究了各向异性的调制:

 (1)改变Fe、Co之间的原子比

 利用射频磁控溅射方法制备了(Fe_(100-y)Co_y)_(0.61)-(B_2O_3)_(0.39)系列样品,结果表明当Co含量在35.0＜y＜77.0之间,各向异性场几乎不随Co含量变化,但其矫顽力逐渐减小,在y=77.0时最小;但当Co含量y＞77.0后,各向异性场迅速消失,其矫顽力迅速增大。

 (2)斜入射

 对(Fe_(23)Co_(77))_(0.61)-(B_2O_3)_(0.39)样品研究了磁各向异性场H_k随入射角度θ的变化关系。发现当入射角度从0°上升到30°时,各向异性场从53 Oe逐渐增大到115 Oe。通过实验研究了样品的各向异性的起源。我们认为该薄膜磁各向异性场是由两部分组成:不可逆部分和可逆部分。不可逆部分可以用各向异性的交换耦合的模型来解释;而可逆部分可用原子对的方向有序来解释。
学位年度:2009

Electromagnetic bifunctional precursor - four thio Foix ene Derivatives and Their Preparation and Characterization of complexes

Title: Electromagnetic bifunctional precursor - four thio Foix ene Derivatives and Their Preparation and Characterization of complexes Author: Wang Yu Degree-granting units: Northeast Normal University Keywords: Four thiosulfate Foix en;; π-d interaction;; complexes;; crystal structure;; phase transition;; water cluster Abstract: Dual-function materials for Neodymium Magnets electromagnetic research is the synthesis and materials chemistry research focus, the origin of the field to the initial
Back for the four thio-Foix ene (TTF) of the study. From the discovery of the first organic metal (TTF) (TCNQ) has been, TTF derivatives have been
Not only can be used as building blocks of organic conductors, but also in molecular machines, organic magnets, organic field-effect transistors, solar
Battery and nonlinear optical materials are widely used, the most active research to multifunctional molecule-based materials are synthesized. Design
Both electrical conductivity and a magnetic molecules (materials) particularly attractive to a lot of interest in chemistry and physics. To achieve this goal
Way in organic π-electron donor and the localized d electrons of the paramagnetic ion coupling established between the π-d interaction, and achieve the π-d interaction
Can usually be used two ways: (a) the interaction through space to achieve π-d interaction, but such interactions will be relatively weak;
(B) the two systems connected by chemical bonds, so as to effectively achieve the π-d interaction. To design each with a strong π-d
Dual role of functional materials, we have successfully synthesized four groups with coordination of the novel TTF derivatives. And using 1 - (4 -
(Tetrathiafulvaleneyl) phenyl) ethanone (TTF-PEO) and 1 - (4-tetrathiafulvalyphenyl) -4,4,4 -
trifluorobutane-1 ,3-dione (TTF-ph-tfacH) were prepared by a solvent-dependent CuBr_42? charge-transfer salts and metals
MII (M = Zn, Co) complexes. This will be the integration of new molecular-based magnetic materials to provide theoretical http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets and experimental basis. Research work
Includes the following four parts: 1, synthesized as a precursor of electromagnetic integration of the four materials in novel TTF derivatives, and through
Through mass spectrometry, infrared, ultraviolet and NMR structural characterization. In which N-(tetrathiafulvalen-4-ylmethylene) -1,2,4 -
triazol-4-amine (1), 4'-tetrathiafulvaleneyl-2,2 ': 6', 2 "-terpyridine (2), 1 - (4 -
(Tetrathiafulvaleneyl) phenyl) ethanone (TTF-PEO) (3) and 1 - (4-tetrathiafulvalyphenyl) -
4,4,4-trifluorobutane-1 ,3-dione (TTF-ph-tfacH) (4) were replaced with single-triazole, terpyridine, benzene
Ethyl ketone and β-diketone ligand groups. The four compounds tested successfully CV step oxidation of TTF radical cation and two
Cation, showing the reversible one-electron oxidation process. Their electrochemical behavior is similar to the parent TTF, so they can be used as
Good for the body material is widely used. While each single compound are replaced by asymmetric molecules, such compounds in non-
Linear optical materials may have potential applications in the field. 2, by changing the solvent to achieve a convenient way to adjust the TTF-PEO's
Charge transfer for the +1 and +2, respectively, synthesized compounds (TTF-PEO) _2CuBr_4 (5) and (TTF-PEO) _2 (CuBr_4) _2 ·
CH_2Cl_2 · CH_3CN (6), crystal structure analysis shows that they belong to the Pī triclinic and orthogonal space group Pbca. Containing a single to take
Substituent of the TTF-PEO will help to significantly reduce the organic donor and the distance between the paramagnetic ion, which is reflected in the 5 has the shortest Br ·
· · S distance, indicating that the TTF-PEO + · electron donor and CuII ions by Br · · · S · · · Br · · · S super-exchange interaction
There may be a strong π-d interaction. With anti-ferromagnetic behavior of compound 5 in the 110-120K observed phase transition occurs, is
These compounds have been reported in the highest phase transition temperature. 3, TTF-ph-tfac enol anion has a strong coordination ability, and
Metal chlorides (Zn and Co) were generated chelating ligand complexes Zn (TTF-ph-tfac) _2 (CH_3OH) _2 (7) and Co (TTF-ph-
tfac) _2 (CH_3OH) _2 (8), each center are bridging two metal TTF-ph-tfac ligand. Electrochemical behavior of the test indicates that the
Dual-function electromagnetic system can be used as precursor materials. 8 shows the magnetic test between the central metal is weak antiferromagnetic interaction.
4, synthesized by single crystal X-ray diffraction characterization of four novel compounds of copper, one-dimensional chain compound {[Cu (terpyOH) (phth)] ·
H_2O} _n (9), dual-core compounds [Cu2 (terpyO) _2 (phth) (H_2O) _2] · 11H_2O (10), mononuclear compound [Cu
(TerpyOH) (SO4) (H_2O)] · 2H_2O (11) and [Cu (terpyOH) _2] · (HBTC) · 2H_2O (12) (terpyOH = 4
'- Hydroxy-2, 2': 6 ', 2 "- terpyridine, phth = phthalate, BTC = trimesic acid) in 9, the phthalate anion
Sub-bridged CuII center to form a Z-infinite chain. Exist in 10 (H_2O) 16 and (H_2O) 10 water cluster containing the formation of a 2D
Water layer. Near a plane through hydrogen bonds formed by the S-and Z-water chain, respectively, 11 and 12 in the crystal structure observed. 12
In, Cu (II) center is six-coordinated, which is coordinated with the five compounds 9, 10 and 11 are different. And in the process of synthesis of compound 11
Found in hydrothermal conditions 4'-bromo-2, 2 ': 6', 2 "- terpyridine molecules occur in situ reaction terpyOH by comparison
The crystal structure of these compounds can be found, when the molecules through hydrogen bonding with terpyOH to build clusters of water molecules when the control system
deprotonation pH values ​​it will be very beneficial. Degree Year: 2009