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The article presents the developing condition of PWM and SVPWM first.Then the theory of SVPWM is discussed in detail.The SVPWM is based on the thought of magnetic chain tracking.It makes the ideal magnetic chain circle of three-phased sysmmetry electric motor supplied by three-phased sysmmetry sine wave voltage for basis,uses the practical magnetic chain vector formed by the different switch modes of three-phased inverter to track the basic magnetic chain circle.During the course of tracking,the inverter changes the switch modes properly to form the PWM waves.Then the modulation wave of SVPWM is analyzed in detail.The modulation wave of SVPWM is implicit,but the analogous modulation wave in A-B-C axis needs to be calculated in order to expose the internal relation of SVPWM and SPWM.That is to show the implicit modulation wave of SVPWM. SVPWM actually is a transformed SPWM ruly sampled by the modulation wave which is injected by the zero prefaces based on space vectors.

本文首先对脉宽调制技术的发展现状进行了综述，在此基础上分析了电压空间矢量脉宽调制技术的发展现状；接着对空间电压矢量脉宽调制技术的基本原理进行了详细的分析和推导，SVPWM是基于磁链追踪的思想，它以三相对称正弦波电压供电下三相对称电动机定子理想磁链圆为基准，由三相逆变器不同开关模式下所形成的实际磁链矢量来追踪基准磁链圆的，在追踪的过程中，逆变器的开关模式作适当的切换，从而形成PWM波；然后详细分析了电压空间矢量脉宽调制技术的调制波，虽然SVPWM法的调制波是隐含的，但是为了揭示SVPWM法与SPWM法的内在联系，需要求出SVPWM在A-B-C坐标系上的等效调制波，也就是将SVPWM的隐含调制波显化；SVPWM实质是一种基于空间矢量在三相正弦波中注入了零序分量的调制波进行规则采样的一种变形SPWM。

Using the formula about the magnetic flux density induced by coil which deduced by Biot-Savart law,this paper deduces the formula about random point's magnetic flux density of hollow column solenoid and deduces the formulas about axial specific magnetic force and radial specific magnetic force by using the field gradient expression of binary function and the expression of specific magnetic force .

利用二元函数的梯度公式及比磁力公式可以得到磁性颗粒在厚壁圆环线圈所产生的磁场任意点的比磁力的轴向分量和径向分量。

In the magnetic fluid magnetic particle even distribution does in the liquid does not have the rule the Brownian movement, after sur- is parallel to the optical transmission direction gradient magnetic field, as a result of the magnetic field and the magnetic particle mutual function, the optical transmission rate can have the remarkable change.

磁性液体中的磁性微粒均匀的分布于液体之中做无规则的布朗运动，当外加1个平行于光透射方向的梯度磁场后，由于磁场和磁性微粒的相互作用，光透射率会发生显著变化，同样加垂直光路的磁场也会影响其光透射率。

This paper presented the research and exploration of mechanism and technics as well as the design of the magnetic circuit of this new compound machining, based on above, establishing the parameter model, meantime, analyzing influential effects on productivity of magnetic and EDM compound machining the holes through large numbers of experiments, including velcoity contrast experiments of pre-compound and after-compound machining with the change of current, velcoity contrast experiments of pre-compound and after-compound machining with the change of magnetic induction, velcoity contrast experiments of pre-compound and after-compound machining with the change of impulse width, experiments of the superficial roughness, experiments of the Electrode wastage, and intersectant experiments analysis as well as the change experiments of current waveforms. Through a number of experiments we analysed the influential effects of magnetic and EDM compound machining, compared the factors with EDM by oneself. A large of experiment records and deducibility have demonstrated that the productivity of magnetic and EDM compound machining is developed by 20%～400% than traditional EDM.

本论文对磁场电火花复合加工这种新的复合加工的机理、工艺和复合加工的磁路设计进行了研究和探索，在此基础上，建立了磁场电火花复合加工的参数模型，同时通过大量的随着电流变化磁场电火花复合前后加工速度对比实验、磁感应强度变化时的加工速度变化实验、随脉冲宽度变化的加工速度实验、表面粗糙度实验、电极损耗量实验、磁场电火花复合加工正交实验分析、电流波形变化等实验，实验分析了影响磁场电火花小孔加工效率的因素，并且跟单一的电火花加工中的影响因数进行了比较，大量的实验数据和理论推导证明磁场电火花复合加工比传统的单一电火花加工的效率提高了20％～400％左右。

Fluxgate sensors have the second harmonic voltage amplitude with the magnetic field strength is proportional to the adoption of second harmonic filter through phase-sensitive detector rectifier, to achieve full-wave rectifier, low-pass filter in through the phase-sensitive detector after the second harmonic into a smooth DC signal, on the one hand to the back of the circuit, on the one hand, the magnetic flux through the door to feedback regulation, the opposite magnetic field generated with the measured magnetic field, so that the work has always been zero fluxgate magnetic field, thus ensuring the most high-precision fluxgate.

磁通门传感器产生的二次谐波电压幅值与磁场强度成正比，二次谐波通过通过滤波器再通过相敏检波器整流，实现全波整流，在通过低通滤波器将相敏检波后的二次谐波转化成平滑的直流信号，一方面送到后面的电路进行，一方面通过反馈调节送到磁通门中，产生与被测磁场相反的磁场，使磁通门始终工作零磁场下，从而保证磁通门的最高精度。关键词：磁通门磁力仪，相敏检波器，磁场

Both methods combined the magnetic microspheres technology with hydrazide chemistry and Lectin, respectively. The hydrazide-functionized magnetic microspheres and GNA-functionized magnetic microspheres are prepared correspondingly. The condition for capturing glycopeptides by hydrazide-functionized magnetic microspheres and immobiling GNA onto the magnetic microspheres was evaluated and optimized, and the specificity and validity of two methods was demonstrated by using standard glycoproteins sample.

试验中分别将肼化学和凝集素与磁性微粒相结合，分别制备出了肼功能化磁粒和GNA功能化磁粒，优化了肼功能化磁粒富集糖肽的条件和GNA固定的条件，并通过标准蛋白样品对两种方法的富集特异性和有效性进行了验证。

Based on the uniform magnetization model of the surface magnetic field distribution on multi pole drum for magnetic encoder , the surface magnetic field distribution on multi pole drum for magnetic encoder was studied with numerical analysis method, and the general expression of surface magnetic field distribution on multi pole drum was found.

基于磁编码器多极磁鼓表露场分布的均匀磁化理论模型，采用数值分析方法计算磁编码器多极磁鼓的表露场分布，得到了多极磁鼓的表露场分布的数值表达式。

The magnetic flux linkage equations and voltage equation are established according to the magnetic circuits and the magnetic conductance equation is listed according to the relations among magnetic flux, current and magnetic circuit.

模型从三相五芯柱变压器磁路出发，建立了磁链方程、电压方程，并根据铁芯和铁轭的磁通和电流关系及磁路关系列出磁导计算方程；给出了仿真模型的参数确定方法，其中参数确定与变压器的结构紧密相关。

Paper in magnetic patterns, pulp to join jiseizai powder, when paper pulp and magnetic powder is closed at magnetic Board shapes implantation magnetic anti-false paper, magnetic powder be 200 screen, and it should also be stain.

在成纸中有明显的磁性图案，纸浆中加入磁性材料粉末，当纸浆和磁性粉末就按磁板图案的形状植入磁性防伪纸中，磁性粉末，应经过200目筛，并还应染色。

The structure could be a magnetic shield, magnetic pole of a write head or some other magnetic structure used in a magnetic head of a magnetic recording system, and has notches formed at both the front end and at the back end.

该结构可以是磁屏蔽件、写头的磁极或者是使用在磁记录系统的磁头中的某其它磁结构，且具有形成在前端和在后端两者处的切口。

Liapunov—Schmidt method is one of the most important method in the bifurcation theory.

Liapunov—Schmidt方法是分叉理论的最重要方法之一。

Be courteous -- even when people are most discourteous to you .

要有礼貌──即使当別人对你最不礼貌的时候。