The Design of an Intelligent Controller of Permanent Magnetic Actuator

The Design of an Intelligent Controller of Permanent Magnetic Actuator
　　As a popular component of middle-voltage breaker, the reliability of its actuator is very important. As a new kind of Actuator of circuit breaker, permanent magnetic actuator (PMA) has many advantages, such as less parts, higher reliability, no maintenance and so on. It provides hardware basement for enhancing stability of breakers and also can be used to realize intellectual control.First of all, a brief introduction of middle-voltage breaker’s actuator is given in this paper. Block neodymium magnet According to the demands of vacuum breaker, the advantages of permanent magnetic actuator is discussed. With that the necessity and the urgency of a new kind of an intellectual actuator is emphasized.Then, according to the characteristic of permanent magnetic actuator, the structure and the operation principles of permanent magnetic actuator is discussed. To establish the theoretical foundation for realizing intellectual control, the magnetism field characteristic of bi-stable permanent magnetic actuator is analyzed.
　　Then the frame of intelligent control system for the single coil permanent magnetic actuator is introduced.In the following parts, the intelligent control system is introduced in details in both hardware and software aspects. The hardware of the system is divided into six parts, such as the power source system, main chip MCU system, data collecting system, display system and the communicate system. And the software is divided into four parts, such as the main part Block neodymium magnet  system, monitor and execute system, status disposing system, and communicate system.At last, we work out the intelligence control system using the single-chip microprocessor of STC89C516RD+ and other parts of unit, according to the single coil permanent magnetic actuator’s characteristic. Seeking for the simple and less cost controller. The device can realize the function of http://www.chinamagnets.biz/ monitoring, protecting, controlling, and measuring. The device can control the operation of the circuit breaker intellectually, and also has the functions of over-current protection, diagnosis and warning for the failure of the operation system.

The Primary Research of the Realation between High-Resolution Magnetic Resonance

The Primary Research of the Realation between High-Resolution Magnetic Resonance Imaging of Carotid Atherosclerosis Plaque and Acute Ischemic Stroke
　　Background: High-Resolution Magnetic Resonance has been gradually used toevaluate carotid atherosclerosis plaque with the merit of noninvasive、safe、goodrepeatable good sensitivity and specificity. It can display the size and the internalcomponent of Block neodymium magnet carotid atherosclerosis plaque and reveal the realation between thischaracter of plaque and acute ischemic stroke.Object: To evaluate the size、the internal component and the type of carotidatherosclerosis plaque of the patient which gets acute ischemic stroke or isasymptomatic.
　　To object the realation between the above character of plaque and thecerebullar acute ischemic locationMethod: 19 inpatients (14 inpatients of actue ischemic stroke and 5 asymptomaticinpatients) were examined by HMRI to evaluate the size、the internal componentand the type of carotid atherosclerosis plaque . then we observe the realation betweenthe character of plaque and the Cerebullar acute ischemic locationResult: 18 patients contains 43 plaques, which the ratio Block neodymium magnet of multi-plaque is 33.33%.In the 36 carotid systems, 30 have plaques in which 13carotid systems has cerebullaracute ischemic locations. The analysis demonstrated that the ischemic location hasno relalation with plaque size(P=0.23)、the ratio of plaque size(P=0.44)、http://www.chinamagnets.biz/ largermaximum wall thickness(P=0.85) and the size of lipid-rich/necrotic core(P=0.15).the analysis demonstrated a significant association between baseline MRIidentification of the following plaque characteristics and subsequent symptoms: thetype of the plaque (P=0.012), presence of a thin or ruptured fibrous cap(P=0.007),the ratio Block neodymium magnet of lipid-rich/necrotic core(P=0.05)Conclusion: carotid atherosclerosis plaque affect cerebullar acute ischemic locationwithout its size but with its type and internal component

稀土La掺杂Ti/Sb-SnO_2电极电催化氧化对硝基苯酚

题名:稀土La掺杂Ti/Sb-SnO_2电极电催化氧化对硝基苯酚
作者:刘春前
学位授予单位:浙江工业大学
关键词:对硝基苯酚(p-NP);;电催化氧化;;稀土
摘要:
 随着现代工业和经济的快速发展,水污染已成为多国家所面临的严峻问
题,阻碍着社会可持续发展的进程。有毒、难生物降解有机污染物的治理因缺乏
有效的处理方法成为水Block neodymium magnet处理领域的难点。本论文以电催化氧化技术为核心处理工
艺、对硝基苯酚(p-NP)为目标污染物,进行了有毒、难生化有机污染物处理的实
验研究。
 采用溶胶-凝胶法制备稀土La掺杂Ti/Sb-SnO_2电极,以对硝基
苯酚(p-NP)为目标有机物,考察电极的电催化性能,对制备温度和La掺杂量进行了
详细的实验研究,确定了适宜的制备条件为热处理温度450℃、La掺杂量0.8%。采
用SEM、EDS、XRD等分析方法表征了电极的形貌、组成及结构。对空白电极和La
掺杂Ti/Sb-SnO_2电极进行了电极的阳极极化线性Block neodymium magnet扫描,考察了空白电极和La掺杂
Ti/Sb-SnO_2电极的析氧电位;并采用破损法测定它们的电极寿命。结果表明La掺
杂Ti/Sb-SnO_2电极具有更高的析氧电位和更长的电极寿命。
 本论文对硝基苯
酚(p-NP)废水降解的影响因素、降解动力学等进行了研究,结果表明,电流密度、
电解质浓度、初始浓度对p-NP降解效果影响较大,p-NP的降解过程遵循一级动力
学方程,总反应动力学方程为:Ct=C0exp(-0.6606C~(-0.2893)J~(-0.2176)M~(-
0.1908)。
 液相色谱和离子色谱检测结果显示,在羟基自由基进攻下,硝基
从分子中脱除,生成了对苯二酚,对苯二酚在羟基自由基的作用下进一步生成苯醌
等中间产物,这些中间产Block neodymium magnet物被进一步氧化开环,氧化成小分子有机酸如甲酸、乙酸
等,最终彻底氧化成二氧化碳和水。
学位年度:2009

Study on the Magnetoelectric Performances of Magnetostrictive/Piezoelectric Laminate Composite

Study on the Magnetoelectric Performances of Magnetostrictive/Piezoelectric Laminate Composite
　　The magnetoelectric (ME) effect of magnetostrictive/piezoelectric (MP) laminate composite is realized by the“product property”, i.e., in a magnetic field, mechanical stresses arise in the magnetostrictive (M) layer due to magnetostriction and are transferred to the piezoelectric (P) layer, where it produces an electric field due to the inverse piezoelectric effect. As such, the ME effect provides a transduction method between magnetic and electric field signals. Important applications of such materials are magnetic field sensors and magnetoelectric transducers, with the main advantage being that they require no external power to operate.Firstly, the theoretical analysis of low frequency magnetoelectric performances in Longitude-Transverse type MP laminate composite is presented. Block neodymium magnet  The magnetostrictive laminate layers are designated to be magnetized in their longitudinal direction, while the piezoelectric layer is designated to be polarized in its thickness direction. The equivalent circuit of the composite is developed based on the constitutive equations of magnetostrictive and piezoelectric effects using the motion equation and circuit status equation. In terms of the equivalent circuit, it is straightforward to obtain the magnetoelectric response of the laminate composite, which is dependent on various parameters of magnetostrictive and piezoelectric materials. According to the theory, a discussion about the affect factors of ME response and a numerical calculation of Terfenol-D/PZT/Terfenol-D laminate composite are given out.
　　The MP laminate composite has dramatically enhanced ME effect when driven near resonance. A theory of the resonant ME effect is investigated using equivalent circuit method, in which the eddy current loss, the mechanical loss and the dielectric http://www.chinamagnets.biz/ loss are all taken into consideration. The results indicate that, when the laminate composite works at resonance, the mechanical loss plays a key role in the dissipation while a strong bias magnetic field is essential to restrain eddy current loss to improve the ME conversion efficiency. In addition, Terfenol-D/PZT-8 shall be more competitive in ME energy conversion near resonance than Terfenol-D/PZT-5.To verify the theoretical results, a ME response measure system is built up. The making procedure of Terfenol-D/PZT-5H sample and the cautions to the test system are introduced respectively. The experiments are processed by the active method and the ME performances are measured. The experimental results indicate, the theoretical value is about 5~8 times as much as the experimental one at low frequency when the losses aren’t taken into account, while the two values are close to each other at resonance in consideration of losses; and the bias magnetic field should be carefully selected to restrain the eddy current loss and adjust the resonant frequency of the composite. 更多还原