Applications of Carbon Nano Materials on Photoanalytical Chemistry

Applications of Carbon Nano Materials on Photoanalytical Chemistry
　　In order to broaden the scope of application of the fullerene (C60) and carbon nanotube (CNT) in the field of photoanalytical chemistry, some investigation had been performed in this dissertation. The dissertation consists of following two parts. In part one, the spectra characteristics of fullerol (C60(OH)n) in water solution as well as the interaction between fullerol and rare earth ions were investigated. And based on the interaction between C60(OH)n/Yb3+ and nucleic acid a new optical chemical method for detecting nucleic acid was developed: (1) The interaction between fullerol (a water-soluble C60 derivative) and several kinds of rare earth ions was investigated by means Block Neodymium magnets of fluorophotometry and the different response characteristics between them were observed. The results showed that the quenching ability of rare earth ions on the fluorescence intensity of fullerol was as follow: Dy3+>Tb3+>Eu3+>Yb3+. (2) Based on the enhancement effect of nucleic acid on the resonance light scattering (RLS) intensity of C60(OH)n/Yb3+ system, a sensitive method for the determination of nucleic acid was proposed.
　　The RLS intensity was proportional to the concentration of nucleic acid in the range of 0-20.0μg mL-1 with the limit of detection of 13.3ng mL-1. In part two, the light scattering phenomenon of multi-walled carbon nanotubes (MWNTs) hydrosol was investigated and new methods for the detection of ascorbic acid (AA) and heavy metal ion (Ag+) were developed: (1) The unique light scattering phenomenon of MWNTs hydrosol was observed. Theλem changed correspondingly along with the change ofλex, and the intensity ofλem increased along with the increase of λex. http://www.999magnet.com/
 Meanwhile a new assay for the determination of AA was established based on the decrease of AA on the scattering light intensity of MWNTs hydrosol. The limit of detection was 3.8×10-8mol L-1. (2) A new method for the detection of Ag+ was proposed based on the enhancement effect of Ag+ on the scattering light intensity of MWNTs hydrosol. The scattering light intensity was proportional to the concentration of Ag+ in the range of 0.0-1.8×10-5mol L-1 with the limit of detection of 1.0×10-7mol L-1.

Study on the Synthesis, Structure and Reactivity of Organolanthanide Complex Supported by Phenoxo Functionalized-NHC Ligand

Study on the Synthesis, Structure and Reactivity of Organolanthanide Complex Supported by Phenoxo Functionalized-NHC Ligand
　　We synthesized and characterized lanthanides amide complexes of (Y, Nd, Sm) supported by aryloxo-functional N-heterocyclic carbene, an bridged bisphenoxide complexe of lanthanide from the cleavage of aryloxo-functional N-heterocyclic carbenes and an ion-pairs complex supported by aryloxo-functional N-heterocyclic carbene precursor. The main results as fellows:1. The amide complex of samarium Li(THF)Sm(NiPr2)4 (1) was synthesized and characterized by the reaction of LiNiPr2 with SmCl3 in 4:1 molar ratio in THF and hexane,2 Reaction of aryloxo-functional N-heterocyclic carbene precursor [HO-4, 6-di-tBu-C6H2-2-CH2{CH(NCHCHN)iPr}]Cl (A) , Li(THF)Ln(NiPr2)4 (Ln= Y, Nd, Sm) and n-BuLi in 2:1:1 molar ratio in THF at -78℃for 10h, and at room temperature Alnico magnets for 12h, gave the corresponding complexes [0-4, 6-di-tBu-C6H2-2-CH2-{C(NCHCHNiPr)}]2 LnNiPr2 (Ln=Y(2), Nd(3), Sm(4)).
　　All complexes were fully characterized by IR, elemental analysis, X-ray diffraction, and by 1HNMR and 13CNMR in the case of Y.3. The catalytic activity of complexes 2, 3 and 4 for e-Caprolactone and L-lactide polymerization were examined. All the complexes can catalyse polymerization of e-Caprolactone and L-lactide, gave the polymers with rather broader molecular weight distribution.4. Reaction of NaOAr, SmCl3 and aryloxo-functional N-heterocyclic carbene precursor [HO-4, 6-di-tBu-C6H2-2-CH2{CH(NCHCHN)Me}]Cl (B) in 4:1:1 molar ratio in THF in one-pot hadn’t afforded an anionic phenoxide complex of samarium (5) supported by a bridged bisphenoxo through the cleavage of aryloxo-functional N-heterocyclic carbenes. The complexes 5 was characterized by IR, elemental analysis, X-ray diffraction.5 Reaction of aryloxo-functional N-heterocyclic http://www.999magnet.com/
 carbene precursor A with NdCl3 in 2:1 molar ratio in THF yielded an ion-pairs complex 6, The complex 6 was characterized by IR, elemental analysis, and X-ray diffraction. The further reaction of 6 with alkali (NaN(SiMe3)2, LiNipr2) were tried and no definite complexes were isolated.

Microstructures and Upconversion Luminescence Properties Investigations on Er3+ Doped SiO2-PbF2-PbO Transparent Glass Ceramics

Microstructures and Upconversion Luminescence Properties Investigations on Er3+ Doped SiO2-PbF2-PbO Transparent Glass Ceramics
　　Rare-earth-doped materials have been extensively investigated because of the promising application in the all-solid-laser, optical communications,etc,recently. And rare earth ions doped oxyfluoride glass ceramics,multi-phase materials with fluoride nanocrystalline in the oxide glass,have attracted much more attention because they combine the lower phonon energy environment of heavy metal fluoride crystal with the better chemical, mechanical and thermal stability of oxide glasses.In this dissertation, the Er3+ doped SiO2-PbF2-PbO glass ceramics were prepared by high temperature sintering method. The influence of different preparation parameters, different matrix Block neodymium magnet composition and different rare earth compounds on microstructure and optical properties of the glasses and glass ceramics were discussed detailed based on the experimental measurement results of differential scanning calorimetry(DSC), X-ray diffraction(XRD), absorption spectra and luminescence spectra.Firstly, the 50SiO2-20PbF2-30PbO-0.5ErF3 glass and glass ceramic were prepared. Because of the reaction SiO2+2PbF2→SiF4↑+2PbO, the composition of PbF2 will decrease during the sintering. To prevent from severe loss of PbF2, the preparation parameters should be optimized.
　　We suggest that when the powder was sintering at 1000℃, the sintering time is about 15min. In order to obtain the ideal size and content of nanocrystals, the heat treatment temperature should be at a temperature about 25℃higher than their glass transition temperature(Tg). It is verified by the XRD analysis that the crystal phase in glass ceramics isβ-PbF2, and the sizes of the precipitated crystallites were evaluated to be 12nm. The intensity of upconversion luminescence in the glass ceramics enhanced drastically compared to that in the precursor glass.Based on the above preparation parameters, four different erbium compounds: Er2O3, ErOF, ErF3 and ErCl3 doped SiO2-PbF2-PbO oxyfluoride glass ceramics were prepared. The results indicated that theΩ2 values of the glass Block neodymium magnet ceramics are much smaller than that of their precursor glasses due to concentration of Er3+ ions into PbF2 nanocrystals after heat treatment. Furthermore, the glass ceramics doped with ErCl3 has the lowest transparency among all. While, the glass ceramics doped with ErF3 was the most beneficial for the precipitation of PbF2 crystallites and had the lowest ratio of red to green emission.To investigate the influence of content of PbF2, the ErF3 doped 50SiO2-xPbF2-(50-x)PbO-0.5ErF3 glass and glasses ceramics were prepared. It was concluded that with the increase of PbF2 content, the ratio of the red to green upconversion luminescence decreased which caused by the decrease of the Er3+ concentration inside the nanocrystallites.

Study on the Ce-Zr-Based Pd Catalysts Modified by Rare Earth Pr Used for the Purification of Automobile Exhaust

Study on the Ce-Zr-Based Pd Catalysts Modified by Rare Earth Pr Used for the Purification of Automobile Exhaust
　　1. A series of industrialγ-Al2O3 were modified by La2O3, they were characterized by using XRD technique. The results reveal that all samples calcined at 950℃have the same structure with freshγ-Al2O3, and the sample modified by wetness impregnation shows the lowest intensity of the diffraction peaks.2. A series of PrxCe0.65-xZr0.35O2(xPCZ) complex oxides with various atomic ratios were synthesized by the citric acid complexation method, and characterized by using TG/DTA、XRD、XPS and H2-TPR techniques. The results of TG/DTA reveal that Ball Neodymium Magnets all the samples have the same weight-loss stages. With the increase of the dopant praseodymium, the formation of complex oxides becomes more difficult. The XRD results display that all samples calcined at both 500℃and 850℃show the same cubic phase structure with the pure CeO2 oxide, while with the increase of the dopant praseodymium, the diffraction peaks shift to higher angle to some extent, Compared with the samples calcined at 500℃, all peaks of the samples calcined at 850℃are more intense and narrow obviously.
　　The XPS results show that Pr and Ce atoms on the surface of all the samples present +4 chemical state, meanwhile, compared with the samples calcined at 500℃, Pr and Ce atoms of the samples calcined at 850℃can transfer from bulk to surface, furthermore, Pr atoms transfer more easily than Ce. The H2-TPR results also reveal that all the samples calcined at 500℃have only a reduction peak. When the percent of the dopant praseodymium increases, the temperature of reduction peak increases, but the peak area seems unchanged. For the samples calcined at 850℃, there are two reduction peaks in the H2-TPR curves. As the amount of praseodymium increases, the low-temperature reduction peak shifts to lower temperature direction, and the high-temperature reduction peak shifts to higher temperature direction, but the total area of these peaks keeps unchanged. The samples without Ce always present reduction peaks at the highest temperature and give the smallest peak area.3. A series of noble metal Pd-based catalysts were prepared by wetness impregnation method, the precious metal http://www.chinamagnets.biz/ was loaded to mixed powder using impregnation directly.
　　The three-way and propane combustion performance of these catalysts were evaluated by using CO、NO and C3H8 as the reactants. The results reveal that CO、NO and C3H8 cannot be eliminated at the same time or at the same temperature region. The propane combustion results show that the C3H8 oxidation efficiency is in good accordance with the reduction tendency of the complex oxides.4. Another series of noble metal Pd-based catalysts were prepared by the citric acid complexation and wetness impregnation method step by step. The catalysts were characterized by using H2-TPR technique. The results reveal that with the increase of the dopant praseodymium there is no obvious difference in the reduction property among these catalysts. The samples without Ce show the worst reduction property.

Study on the Nigrescence Mechanism of Lanthanon Luminescent Material Frictionizing with Metals

Study on the Nigrescence Mechanism of Lanthanon Luminescent Material Frictionizing with Metals
　　Accumulating luminous fibers are produced in the way of melting and matrix spanning. Its basic material is terylene resin, and lanthanon aluminates atom and assist acidifier of nanometer are appended in. If only this fiber absorbs any visible light for 10 minutes, it can store up light energy in, and shine in the dark. Moreover, it can be used infinitely. It can be widely used in aviation and navigation, defence industry, construction project and decoration, transportation , nighttime neodymium magnets working, everyday life and entertainment costume, etc.The more used luminous material is the rare-earth aluminates phosphorescence material in which SrAl2O4:Eu2+,Dy3+ is the most widely used. Luminous fiber was made by the filature process of co-mixing of the luminous powder and the polymer.
　　The luminous fiber which made in the co-mixing way was found nigrescent. It not only affects the textile fiber’s outward appearance but also the brightess.As the effects of the screw-melt-fed spinning machine and the blender are the similar, blenders are used to simulate the luminous fiber’s production process. SrAl2O4:Eu2+,Dy3+ powder was been put into different vessels and stirred under dissimilar conditions. Different factors that made powder nigrescent was studied. The conclusion is that stirring in nonmetallic vessels such as glass, ceramic and plastic SrAl2O4:Eu2+,Dy3+ powders will not nigrescent while in metallic vessels will nigrescent. Metal type is the primary factor of SrAl2O4:Eu2+,Dy3+ powder’s nigrescent. Chemic analytical method,Thermo-gravimetric and http://www.chinamagnets.biz/ Differential thermal analysis (TG-DTA), X-ray diffraction(XRD) and Scan electron microscope(SEM) are used to analyse the nigrescent powder. The nigrescent mechanism is that erosion made metallic oxide mixed in the powder.

Effect of Rare Earth Yttrium on Microstructure of Rapidly Solidified Titanium Aluminum Based Alloys

Effect of Rare Earth Yttrium on Microstructure of Rapidly Solidified Titanium Aluminum Based Alloys
　　TiAl-based alloys are one kind of attractive materials for high temperature structural applications because their outstanding mechanical properties such as high specific strength, good creep strength and acceptable oxidation resistance. But their ductility at room temperature is very low, which is the main obstacle to TiAl-based alloys for their applications in aerospace and aircraft. The present paper adopted rapid solidification technique, -melt spinning, to prepare Ti-46Al-2Cr-2Nb based alloys with various Y contents (0, 0.5, 1.0, 1.5, 2.0 at.%). The influence of Y Special shape NdFeB magnets addition and rapid solidification technique on the microstructure and mechanical properties of the alloys was investigated intensively, in order to explore a novel approach of ductility improvement of TiAl based alloys.OM, SEM, EPMA and TEM observations of as ingots and rapidly solidified alloys are performed to show the solidification microstructure.
　　And XRD technique is employed to analyze the phase configuration.It was found that, the microstructure of as cast alloys which addition of 0.5 to 1.0at.% Y are lamellar, Al2Y phase distribute on the grain boundaries as discontinuous reticulation,but 1.5 and 2.0 at.% Y added alloys are spatulate microstructure, Al2Y phase distributes on the grain boundaries as continuous reticulation. With the increasing Y content, the secondary dendritic arm spacing (SDAS) is gradually reducing. Microhardness tests showed a monotonic increase with the increasing of Y content. This is attributed to the strengthening effect stemming from the refined microstructure.For the rapidly solidified alloys, it was found that the microstructure was refined evidently and the SDAS decreases Special shape NdFeB magnets comparing with the as cast counterpart. The Y-rich phase was found to distribute homogeneously on the matrix as very fine precipitates (with a particle size of several tens of nanometer). XRD results showed that B2 phase (a=0.314nm) appears in the alloys containing more than 1.5 at.% Y, rapid solidification extends theβphase region, and retains it to low temperature, leading to a transformation from high temperatureβphase to ordered B2 phase during cooling. Nano-Indentation tests of the rapidly solidified alloy ribbons indicate that, with increasing of Y content the hardness of ribbons does

Studies on Anti-tumor Effect of Rare Earth Cerium and It’s Mechanism

Studies on Anti-tumor Effect of Rare Earth Cerium and It’s Mechanism
　　Tumor is one of major diseases that threat the health of people severely.Drug treatment is one of the effective therapeutic approaches for tumortreatment. At present, there are many kinds of the anti-tumor medicine that hasthe properties such as low-selectivity, high-toxicity and drug-tolerance, so thatthe effective of chemotherapy is not satisfying. Thus, it becomes a hot spot ofstudy to develop a new chemotherapy medicine. The aim of this study is supply theory-support for the development ofnew chemotherapy medicine by investigating the anti-tumor activity of rareearth Cerium and approaching the mechanism of the activity in vivo and vitro. 1. Toxicity of Cerium nitrate in Vitro The study used MTT method to detect the toxic activities of Ceriumnitrate on FL cell lines and L929 Block Neodymium magnets cell lines in vitro. The results showed that:There won’t toxic activities even were advance-growth activities on both celllines when the experimental concentration of Cerium nitrate were low to 0.64mmol·L-1 except on L929 cell lines at the dosage of 0.16 mmol·L-1. 2. Anti-tumor Activity of Cerium nitrate in Vitro The study used MTT method to detect the anti-tumor activities ofsodium nitrate on HeLa cell lines and Cerium nitrate on seven cancer celllines: HeLa、 SMMC-7221、SGC-7901、 B16、 Lewis、K562 and H22 celllines. The results showed that :The first, comparing with CG, Sodium nitratehadn’t distinguished inhabitation of the growth and proliferation of HeLa celllines on all groups. The second, comparing with CG, Sodium nitrate hadnoticeable inhabitation of growth and proliferation of cancer cells listed abovein vitro on 0.64 mmol·L-1、1.28 mmol·L-1、2.56 mmol·L-1 and 5.12 mmol·L-1;Sodium nitrate inhabit the growth and proliferation of cancer cells includingHeLa、SGC-7901、B16 and K562 on 0.08 mmol·L-1;Sodium nitrate hadnoticeable inhabitation of the growth and proliferation of H22 cell lines invitro on 0.04 mmol·L-1 and 0.01 mmol·L-1. The third, Sodium nitrate hadnoticeable inhabitation of the colony formation of cancer cells including B16and SGC-7901 on 0.08 mmol·L-1 and 1.28 mmol·L-1.3. Melanin pigment production of B16 cell linesThe study detected the content of melanin of B16 cell lines byspectrophotometer.
　　The results showed that: Cerium nitrate can promotemelanin pigment production of B16 cell lines.4. Effect cell cycle of Cerium nitrate in VitroThe study used One-Fluorescence Dying method on Flow Cytometer todetect the cell cycle of Cerium nitrate on SGC-7901. The results showed that:After Cerium nitrate affect tumor-cell-lines for 48 h, Cerium nitrate coulddelay G0/G1 and shorten S of cell cycle at the dosage of 0.08 mmol·L-1 ,at thesame time Cerium nitrate can delay G0/G1、G2+M and shorten S of cell cycleat the dosage of 1.28 mmol·L-15. Anti-tumor Study of Cerium nitrate in VivoThe study set up KM bearing H22 mice model by injecting tumor cellson left inguinal groove. Then treated with Cerium nitrate (50、100、200mg·kg-1) for twoweeks. After that , the study measured mouse weight、tumor weight、thymus weight、spleen weight and liver weight and calculated increment of weight、inhibitionratio、thymous Index 、spleen Index and liver Index. The results showed that:①The increments of weight of experimental group were not different fromthat of CG. There was obviously different between CYT and CG. It wasreflected by this result that the experimental group’s effect of increment ofweight was less comparing with CYT. ②The tumor weight of experimentalgroups and CYT were lower by far comparing with CG and this resultreflected that Cerium nitrate can inhibit the growth of tumor. In addition, LDof Cerium nitrate had higher inhibition (47.8%) than other experimentalgroups and approached CYT. ③The thymus Indexes of LD and MD werehigher than that of CG Block Neodymium magnets and the thymus Indexes of experimental groups weresignificant higher than that of CYT. The spleen Indexes of experimentalgroups were higher than that of CG and especially the spleen Indexes of MDwere obviously higher than that of CG and there were not notable differentbetween experimental groups and CYT in spleen Indexes. These resultsreflected that Cerium nitrate could activate immune organ and toxicity ofCerium nitrate was lower than that of CYT on immune organ. ④Except forLD other experimental group’s and CYT’s liver Indexes were not obviouslydifferent from the liver Index of CG.
　　This result reflected that Cerium nitratecan’t harm the stomach of mice by intragastric administration for short time.6. T Lymphocyte TransformationThe http://www.999magnet.com/ study used MTT method to detect the T lymphocyte transformationof Cerium nitrate on KM bearing H22 mice. The results showed that: The Tlymphocyte transformation rates of MD and CYT were higher than that of CGand the T lymphocyte transformation rate of LD was obviously higher thanthat of CG. This result reflected that Cerium nitrate can promote T lymphocytetransformation and enhance immunity.7. SOD Activity and GSH Level in Blood SerumThe study used kit standard method (Nan Jing Jian Cheng Sheng WuGong Cheng Yan Ju Suo) to detect the SOD activity and GSH level in bloodserum of bearing H22 mice. The results showed that: ①The SOD activity ofMD was higher than that of CG and The SOD activity of LD was obviouslyhigher than that of CG. The SOD activities of all experimental groups werehigher than that of CYT. ② The GSH levels of all experimental groups andCYT were higher than that of CG and The GSH level of HD was notablyhigher than that of CG. These results reflected that Cerium nitrate can enhancethe SOD activity and raise the GSH level in blood serum and promotecapabilities on anti-oxidation Block Neodymium magnets and anti-mutation.8. TNF Activity in Blood SerumThe study used MTT method to detect the TNF activity in blood serumof bearing H22 mice. The result showed that: The TNF activities of allexperimental groups and CYT were minute lower than that of CG. This resultreflected that Cerium nitrate can’t enhance the TNF activity in blood serum.CONCLUSION: We consider that Cerium nitrate has the property thatis low toxicity and high selectivity, at the same time it can inhibit growth andproliferation of so many kinds of tumor cell lines by adjusting cell cycle、inhibiting DNA synthesis、promoting T lymphocyte transformation、enhancingSOD activity and raising GSH level. In addition to we discover that Ceriumnitrate can promote the differentiation of tumor cell.

纳米复合氟化物的制备及其荧光性质研究

纳米复合氟化物的制备及其荧光性质研究
　　It still remains an open challenge to identify a suitable synthetic route for growing high-quality (monodisperse, single-crystalline, wellshaped, and phase-pure) products of a given inorganic material. Herein, we report the first synthesis of monodisperse nanocrystallines of hexagonal phase NaYF4 and YOF via a non-toxic inorganic single-source precursor NaY(CO3)F2 route.In present work, different reaction parameters such as solvent, reaction time and temperature were studied for the phase, size, and morphology control of the precursor and product nanocrystallines. Segment neodymium magnets Both Eu3+ doped NaYF4 and YOF can be synthesized using the same ISSP, NaY(CO3)F2: Eu3+, by hydrothermal and heat treatment respectively. When the precursor was treated hydrothermally at 230℃for 10 h, hexagonal phase NaYF4: Eu3+ nanocrystallines were prepared. When the precursor was pyrolyzed at 400℃for 1 h in air atmosphere, YOF: Eu3+ nanocrystallites were the final product. The products were measured by means of XRD, SEM, TEM, Photoluminescent spectra.
　　The results are shown that , the NaYF4: Eu3+ and YOF: Eu3+ particles possesses high purity, sphere-like shape, nano size, excellent nanodispersity. The size of NaYF4: Eu3+ was about 20 nm while that of YOF: Eu3+ is little larger, about 30 nm, which may be related to the crystal growth under elevated temperatures. Eu3+-doped NaYF4 and YOF nanocrystallines were used for the photoluminescence examinations. Intense red luminescent light was observed for Eu3+ doped NaYF4 and YOF nanocrystallines excited at 245 nm at room temperature.The thermal decomposition of rare earth fluorocarbonate can be extended to prepare other rare earth Segment neodymium magnets complex fluoride and oxyfluoride and will have a good morphology features. When the inorganic single-source precursor Yb3+/ Er3+ co-doped LaCO3F was pyrolyzed at 460℃for 2 h in air atmosphere, LaOF:Yb3+/ Er3+ nanocrystallites were the final product. The broad diffraction peaks of the XRD pattern showed the product to be of the nanometric size regime with high purity.
　　The TEM images showed the size of LaOF: Yb3+/ Er3+ particles were close to spherical particles with the size about 40 nm. Excited with a 980 nm laser sourc, intense upconversion luminecense was observed for LaOF: Yb3+/ Er3+ particles at room temperature using the naked eye. The thermal decomposition of rare earth fluorocarbonate is a facile nontoxic synthetic route for the preparation of complex fluoride and oxyfluoride nanocrystallines. Other rare earth or transition metal complex fluorides and oxyfluorides may also be synthesized using the present technique. In a typical procedure, NaYF4 was synthesized by hydrothermal reaction of metal nitrates and NaF at 200℃for 12 h. The product is amixture of the cubic phase and the hexagonal phase NaYF4 with the n(F)/ n(Y3+) ratio is 6. It is beneficial to the transformation from cubic phase to the hexagonal phase NaYF4 when improving stirring speed or adding a certain quantity of Na2CO3(1 mmol). When the n(F)/ n(Y3+) ratio is 9, the pure hexagonal phase NaYF4 with rodlike structures can be obtained easily.A series of NaYF4: Yb3+/ Er3+, NaYF4: Yb3+/ Tm3+, NaYF4: Yb3+/ Er3+/ Tm3+, NaYF4: Yb3+/ Er3+/ Segment neodymium magnets Mn2+ samples were synthesized by hydrothermal method. The green-red emissions were generated by NaYF4: Yb3+/ Er3+ phosphor. The experimental results indicate that the upconversion(UC) green light decreased obviously compared with the variation of red light when increasing amount of Mn2+ ion. The optimum color ratio was tuned by Mn2+ doping cation. The blue emission was from NaYF4:Yb3+/ Tm3+ phosphor. Bright upconversion white light was observed by the combination of NaYF4: Yb3+ 20 %, Er3+2 %, Mn2+ 50 % green-red phosphor and NaYF4: Yb3+ 20 %, Tm3+ 0.2 % blue phosphor.

The Synthesis and Luminescent Properties of Rare Earth Doped in Aluminoborate Phosphors

The Synthesis and Luminescent Properties of Rare Earth Doped in Aluminoborate Phosphors
　　Aluminoborate phosphors have not only the very strong absorption in the VUVscope, but also the good bearing to the vacuum ultraviolet ray exposure and theanti-ion bombardment. Moreover it has many characteristic for good thermostability,low synthesis temperature and high efficient luminescence.This paper made up by two kind of aluminoborate matrix of SrAl2B2O7 and YAl3(BO3) 4 synthesized by sol-gel method.And it obtains highly efficient red and greenaluminoborate luminescent materials. It makes a consideration on the best synthesiscondition, like the rare earth ionic radius, the concentration quenching, the synthesistemperature, time, atmosphere and matrix composition effects on the luminousperformance. In this paper, Mn2+ doped ZnS nanoparticles were also synthesized by ahydrothermal method.
　　All the work and summary induction as follows:1.Cylinder neodymium magnet  The synthesis and luminescent properties of rare earth doped in SrAl2B2O7 hosts.The hosts SrAl2B2O7 single-cubic phase were fabricated by the sol-gel method. Itmakes a discussion on the concentration quenching, the synthesis temperature, time,atmosphere and matrix composition effects on the luminous performance when therare earth Eu3+, Tb3+ and non-rare earth Ba2+,Ca2+,Gd3+,Li+ doped in SrAl2B2O7 hosts.①The structures of the phosphors were characterized by XRD. The dopingcontent of Eu3+ ions in SrAl2B2O7: Eu3+ phosphors are 1%, 4%, 6%, 8%, 10% (molarfraction), respectively. Luminescence properties were analyzed by measuring theexcitation and emission spectra.The luminescent properties of SrAl2B2O7: Eu3+phosphors are discussed. It is shown that from 4% of Eu3+ doping concentation inSrAl2B2O7 under 392nm excitation is optimum. In stead of Sr2+ with Ba2+ (5%) andCa2+ (10%), it could improve the photoluminescent intensty of Eu3+. ②SrAl2B2O7: Tb3+ phosphors were fabricated by the sol-gel method. Thestructures of the phosphors were characterized by XRD. The doping concentrationof Tb3+ ions in SrAl2B2O7: Tb3+ phosphors are 0.5%,5%,11%,13% ( molarfraction),respectively.The photoluminescence properties of SrAl2B2O7:Tb3+ wereexamined by the Cylinder neodymium magnet  excitation and emission spectra.
　　The luminescent properties ofSrAl2B2O7: Tb3+ phosphors are discussed.It is shown that the 11% of dopingconcentration of Tb3+ ions under 237nm excitation in SrAl2B2O7: Tb3+ phosphors isoptimum. In stead of Sr2+ with Gd3+ (10%) and Li+ (1%), it could improve thephotoluminescent intensty of Tb3+.2. The synthesis and luminescent properties of rare earth doped in YAl3(BO3)4 hosts.①YAl3(BO3)4:Eu3+ phosphors were fabricated by the sol-gel method. Thestructure properties were measured by TG-DTA, XRD and IR. The dopingconcentration of Eu3+ ions in YAl3(BO3)4:Eu3+ phosphors are 0, 1, 3, 4 and 5 % (molarfraction). The excitation spectra and emission spectra of YAl3(BO3)4:Eu3+ phosphorswere examined by fluorescent divide spectroscopy (FDS). The luminescent propertiesof YAl3(BO3)4:Eu3+ phosphors are discussed. It is shown that the 3 % of dopingconcentration of Eu3+ ions in YAl3(BO3)4:Eu3+ phosphors is optimum.②YAl3(BO3)4:Tb3+ phosphors were fabricated by the sol-gel method. Thestructure properties were measured by XRD. The doping concentration of Tb3+ ions inYAl3(BO3)4:Tb3+ phosphors are 013% (molar fraction). The http://www.chinamagnets.biz/ excitation spectra andemission spectra of YAl3(BO3)4:Tb3+ phosphors were examined by fluorescent dividespectroscopy (FDS).
　　The luminescent properties of YAl3(BO3)4:Tb3+ phosphors arediscussed. It is shown that the 11 % of doping concentration of Tb3+ ions inYAl3(BO3)4:Tb3+ phosphors are optimum.3. Hydrothermal preparation and properties of nanocrystalline ZnS:Mn①In this paper, Mn2+-doped ZnS nanoparticles were synthesized by ahydrothermal method .The effect of the different ratios of the precursor concentrations[S2-]/[Zn2+] , the Mn concentration , the synthesis temperature and the PH value hasbeen studied.The sample were observed to have cubic structure over the Mnconcentration from 1% to 20% and the hydrothermal synthesis temperature from 70oCto 110oC.Photoluminescence intensity in ZnS:Mn showed significant change with theratios of the precursor concentrations [S2-]/[Zn2+] , slight change with the temperatureand PH valve , and the enhancement upon Mn incorpatation.It has the problems to improvement as follows:1. The rare earth dopes in the MAl2B2O7 system is a new Cylinder neodymium magnet  research direction, which itneeds very most data and theory to consummate. For example:CaA12B27:RE(RE=Eu3+,Ce3+, Tb3+, Gd3+,Gd3+、Ce3+和 Tb3+,Dy3+,Eu2+),SrA12B207:RE (RE= Ce3+, Gd3+,Gd3+、Ce3+和 Tb3+, Dy3+, Eu2+),BaA12B207:RE(RE=Eu3+, Ce3+, Tb3+, Gd3+,Gd3+、Ce3+和 Tb3+, Dy3+). The spectrum data in the UV-Vis scope excitation and emission Underthe VUV excitation, as well as theory research needs to improve.2. It should be consummated the SrA12B207,YAl3(BO3)4 systems, like photolumineousbrightness, the life as well as its actual application value.3. The study on the structure and luminescent properties of the rare earth doped in thenew aluminoborate system Na2Al2B2O7, K2Al2B2O7.

The Research of the Synthesis of Manganese Minerals and the Adsorption of Rare Earth Elements by the Manganese Minerals

The Research of the Synthesis of Manganese Minerals and the Adsorption of Rare Earth Elements by the Manganese Minerals
　　This paper, firstly, introduces the types of manganese in the nature and the characteristics of the structure and formation of vernadite and birnessite in the ferromanganese nodules and cobalt-rich crusts. Then, it describes the methods to synthesize these two manganese minerals, as well as contast with the natural vernadite and birnessite. The powder XRD pattern of the synthetic birnessite provides four obvious characteristic peaks, 0.712nm,0.355nm,0.248nm and 0.144nm,and the synthetic sample is quite pure.The SEM pattern shows plate or laminated aggregate,Block neodymium magnet and the laminated structure.The IR pattern shows a strong peak at 644 cm-1.The powder XRD pattern of the synthetic vernadite provides two characteristic peaks, 0.240nm and 0.139nm, and the intensity is low. There are many dispersion peaks. The synthetic sample is quite pure. The SEM pattern shows curl lamina, slender fibre, and also the laminated structure. The IR pattern shows a Block neodymium magnet strong peak at 635 cm-1.The crystallinity of the systhetic birnessite and vernadite is not very good,and the pellet is tiny,some present in the amorphous state. That is because of short time of systhesis and atmospheric pressure.

Effect of the Type of Rare-Erath Oxides on the Oxidation and Thermal Shock Behavior of In-Situ α-Sialon

Effect of the Type of Rare-Erath Oxides on the Oxidation and Thermal Shock Behavior of In-Situ α-Sialon
　　α-Sialon ceramics composites doped with Nd, Sm, Dy, and Yb rare-earth additives were synt-hesised by hot-pressing. The effects of adding excess 2 wt.% rare earth oxide as sintering aids on the densification, phase components, and microstructure were studied by XRD, SEM and TEM. Room temperature flexure strength and fracture toughness were measured through three-point bending, and single-dege-notch beam bending method. The influence of the rare earth, phase Ball Neodymium Magnets components, and microstructures on the themophysical properties, thermal shock and oxidation resistance of the composites had been investigated.Results showed that all theα-Sialon ceramics achieved densities higher than 98% of their theoretical values after hot pressing at 1800℃for 1h under pressure of 30MPa in a nitrogen atomosphere of 0.1 MPa.
　　The Dy and Yb-dopedα-Sialons were successfully densified by adding 2 wt.% corresponding rare earth oxide as additives, and by using utrafine Si3N4、AlN、Al2O3 and RE2O3(RE= Dy and Yb)as the starting powders.XRD results revealed that the Nd-Sialons hadα-Sialon, trace ofβ-Sialon and M′(R2Si3-xAlxO3+xN4-x) in their phase components regardless of the 2 wt.% excess rare earth oxide. On the contrary, the other Sm-, Dy-, and Yb-sialon were pureα-Sialon, and had high hardness (Hv10=21GPa), accordingly.The microstructure of the materials varied with rare earths. Yb and Dy-sialon obtained fine equiaxed grains in their microstructures, because that the smaller rare earths promoted the formation ofα-Sialon. After the transient liquid was depleted, anisotropical growth of theα-Sialon was stunted.
　　This was contrarory to the case of Nd and Sm-Sialon, Ball Neodymium Magnets where elongated grains were presented. The flexure strength and fracture toughness of the materials falled into the range from 300MPa～600MPa and 5.1MPa·m1/2, depending on their microstructures. Elongated grains of composites impart high toughness and strength to the material throngh energy-absorbing mechanisms of crack bridging,grain pullout,and crack path deflection.The research results show that the composites have excellent thermal shock resistance propertier. The minimum residual strength remained 75% of its original flexural strength at a thermal shock resistance temperature dirrerence (△T) up to1200℃. The residual strength of the composites improved at a thermal shock resistance temperature dirrerence (△T) up to1100℃after water quenching for 14 times.Combination of the excellent mechanical properties together with the good thermophysical properties result in its excellent thermal shock Ball Neodymium Magnets resistance properties.The high temperature oxidation resistance of -Sialon ceramics composites doped with different rare-earth additives was farely good. Weigh gains by area at 1300℃for 32h were 3.5 mg/cm2 for NdE2 and NdE0, but 1.5 mg/cm2 for SmE2, DyE2, YbE2 materials. Oxidation activation energies of NdE2, NdE0, SmE2, DyE2,YbE2,were determined to be 475kJ/mol,488kJ/mol,505kJ/mol,512kJ/mol, 515kJ/mol respectively.

Synthesis and Characterization of Rare Earth Metal Complexes of 1’-Ethylferrocenylcarbonyl Hydrazine

Synthesis and Characterization of Rare Earth Metal Complexes of 1’-Ethylferrocenylcarbonyl Hydrazine
　　Rare earth metal complexes of ferreocenylcarbonyl hydrazineLnL3(ClO4)3·nH2O(where Ln=La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu;n=1-5)have been synthesized and characterized by elemental analyses, electricalconductance, IR and 1HNMR spectra. The redox properties of ligand and some of itscomplexes have been investigated by cyclic voltammetric method. The solidfluorescence spectra of Sm(Ⅲ), Eu(Ⅲ), Th(Ⅲ), Dy(Ⅲ) complexes have neodymium magnets also beenstudied.The ligand L(L=1’-ethylferrocenylcarbonyl Hydrazine)is bidentate, coordinatingthrough the amino N atom and the carbonyl O atom. The complexes are electrolytesof 1:1 style and one of perchlorate anions is http://www.chinamagnets.biz/ outer sphere.

Microstructure and Mechanical Properties of Extruded Al-Mg-RE Alloys

Microstructure and Mechanical Properties of Extruded Al-Mg-RE Alloys
　　Aluminum alloys have such characteristics as low density, high specific strength and rigidity, and have found a wide application in aeronautical and automotive industries. To extend the application field of aluminum alloys, some measures, which can improve the microstructure, strength and plasticity of aluminum alloys, have to be taken. Usually, the rare earth elements are recognized as one of the most effective elements available to improve both microstructure and property of aluminum alloys. And thus, research concerning the action of rare earth elements in aluminum alloys is of both important theoretical referring value and practical directing significance for developing neodymium magnets new aluminum alloys with high strength and ductility.In this investigation, the Al-4%Mg alloy is chosen as the master alloy. Through adding Ce and Nd as well as melting, casting and hot extrusion, the Al-Mg-RE alloys with different contents of Ce and Nd have been fabricated. The microstructural observations show that the addition of rare earth elements can refine the grains in the extruded Al-Mg-RE alloys, and the effect of the grain refinement is related to the adding content of rare earth element. In addition, it has been found that the addition of rare earth elements will result in the precipitation of secondary phase containing RE.
　　The results of tensile experiments reveal that the addition of Ce and Nd can significantly enhance the ultimate tensile strength and yield strength of the extruded Al-Mg-RE alloys. Especially when 0.5%Ce is added, the ultimate tensile strength of the alloy increases by 30.2%, and the yield strength increases by 47.9%. On the other hand, adding an appropriate content of Nd can increase the elongation of the extruded Al-Mg-RE alloy. When the adding content of Nd is 0.5%, the elongation to failure can be as high as 34%.The results of low-cyclic fatigue tests show that the addition of Ce and Nd can effectively enhance the fatigue lives of the extruded Al-Mg-RE alloys. During fatigue deformation, the extruded Al-Mg-RE alloys exhibit the cyclic strain hardening, softening and stable neodymium magnets cyclic stress response, which mainly depends on the imposed total strain as well as type and amount of the added RE elements. For the extruded Al-Mg-RE alloys, the relation between plastic and elastic strain amplitudes as well as reversals to failure can be described by Coffin-Manson and Basquin equations respectively. In addition, at the higher total strain amplitudes, a serrated flow can be observed in theσ-ε. hysteresis loop for the extruded Al-Mg-RE alloys. It means that the so-called dynamic strain aging takes place during fatigue deformation.The fractographic results reveal that under tensile loading http://www.chinamagnets.biz/ conditions, the extruded Al-Mg-RE alloys show typical ductile fracture, while under low-cycle fatigue loading conditions, the cracks initiate transgranularly at the surface of fatigue samples and propagate in a transgranular mode.

The Influence of Rare Earth Modification on SAPO-11 Molecular Sieve for Lube Oil Isodewaxing

The Influence of Rare Earth Modification on SAPO-11 Molecular Sieve for Lube Oil Isodewaxing
　　The paraffins in lube base oil weaken the low-temperature properties, which should be removed. The isomerized dewaxing technology has advantage in high yield, low cost and perfect base oil quality, which uses“metal-acid center”bifunctional catalyst, such as Pt/SAPO(Silicoaluminophosphate) -11. The resource of RE (rare earth) in China is abundance. Making use of RE has important significance. In this research, two stepwise experiments were carried out to accomplish the RE modification on SAPO-11.First of all, SAPO-11 molecular sieve was modified with La and Ce by impregnating and ion-exchanging methods. The modified samples were characterized by XRD, BET, PSD, FTIR and NH3-TPD, also evaluated by micro-reaction employed the dodecane as model compound. The Block Neodymium magnets results indicated that after RE modification, especially for the La-exchanged sample, the composition of molecular sieve was changed and the crystallinity decreased. Owing to the RE cations loaded on the surface of molecular sieve, which could be regarded as the Lewis acid, the amounts of Lewis acidic sites increased and further the B/L reduced. Meanwhile, the ability of RE cations to acquire electron is weaker than Al3+, so the bond strength of bridged hydroxyl after modification was decreased.
　　Furthermore, After RE modified, the selectivity decreased but the cracking activity increased, especially for the Ce samples.Afterward, base on the results of first stage, the SAPO-11 molecular sieve was modified by Ce in company with Zr using various methods. The modified samples were characterized by BET, H2-TPR, FTIR, and also investgated their performance in isomerization of n-paraffins by micro-reaction. Among all the catalysts in the second stage, the Ce/Ce, Zr impregnating samples’surface aera decreased slightly. The reductive temperature of PtO2 ascended. The Pt had lower metal dispersion and larger particle diameter when the surface area of http://www.999magnet.com/ carrier was smaller. The addition of Zr adjusted the acidity distribution, resulted in the B/L increase. The RE modified Pt/SAPO-11 had lower i-dodecane selectivity and yield. Moreover, the cracking activity enhanced and the optimal temperature debased after RE modified. The catalyst modified with CZ had relative higer B/L, but the selectivity of it was inferior to blank sample.To sum up, the RE modificaions made against the isodewaxing of lube base oil. 更多还原

Study of Growth and Photorefractive Anisotropy of Fe-Mn Codoped Lithium Niobate Crystal

Study of Growth and Photorefractive Anisotropy of Fe-Mn Codoped Lithium Niobate Crystal
　　The rare earth co-permeation were carried out on Kn [SiX3(OH2)3W9O37] (n=7 or 10 , X= Cu3+ , Fe3+ , Co3+, Mn2+, AI3+) with Keggin structure polyoxometalates (POMs) to prepare the KxLnyWO3 at 500℃, 550℃, 600℃, 650℃and 700℃. Moreover, the products were examined with XRD measurement. The result showed that the KxLnyWO3 has the tetrahedral symmetry. It was discussed that reactive temperature, permeating reagent and reactive Ball Neodymium Magnets time influence on prepared compounds and found the optimal method to prepare the rare earth tungsten bronze. 700℃,650℃,600℃,550℃and 4 hours are ideal for preparing the rare earth tungsten bronze by rare earth co-permeation with precursors of Kn [SiX3(OH2)3W9O37] respectively. There is no evidence that the formation of rare earth tungsten bronzes by rare earth reagents.The rare earth tungsten bronze were investigated by X-ray photoemission spectroscopy (XPS) and the result showed that the minimum Nd and La can permeate into the interface of the compounds and they are in formating of Nd+3 and La +3. There are two different W states that areW 6+ and W5+ while there is one O state. Moreover the thermal stabilities of the rare earth tungsten bronze were characterized http://www.chinamagnets.biz/ by TG-DTA. There are exothermic peaks at temperature of 300℃and temperature of 400℃, weight gain and weight loss in the TG curve respectively.The conductivity of the rare earth tungsten bronze has been measured with the electrode method. The result indicated that the conductivity of SiW9Cu3 after permeation in LaCl3 the value is 2.03 S·cm-1 and in CeCl3 the value is 0.0834 S·cm-1. The conductivity of tungsten bronze at different temperature was also determined and result showed that there are two processes. 更多还原

Preparation and Characterization of Up-Conversion Nanocrystal NaYF4 Co-Doped with Rare-Earth Ions

Preparation and Characterization of Up-Conversion Nanocrystal NaYF4 Co-Doped with Rare-Earth Ions
　　Up-conversion luminescence nanocrystal NaYF4 co-doped with rare-earth ions was prepared by hydrothermal method in the prescence of complexing agent EDTA. The optimum composition of four types of samples were discussed respectively, and optimally annealing temperature was determined. The ability of agent EDTA controlling the particle size was also neodymium magnets discussed.The phase, structure and surface topography were analysised by X-ray diffraction, transmission electron microscope and scansion electron microscope. The results showed that hexagonal nanocrystal NaYF4 was prepared by hydrothermal method. The up-conversion spectrum was measured by Hitachi F-4500 spectrophotometer, under 980 nm diode laser excitation. The impact of different concentration of rare-earth ions on the up-conversion luminescence intensity was discussed. The relationship between up-conversion relative intensity and pump power was also studied. Ground state absorption, http://www.chinamagnets.biz/ excitation state absorption and energy transfer were used in discusing the up-conversion mechanism of the nanocrystal and the pertinent up-conversion mechnism models of the nanocrystal were proposed. 更多还原