查询词典 directional field

Perpendicular search engine is to pour pyramid model, be pair of trade news comb, rework and editor are arranged, it is the professional search engine that is aimed at certain industry, the fractionize that is search engine and outspread, it is right some kind of technical information in webpage library undertakes conformity, directional cent field is draw-out the user is returned with some kind of form again after the data that gives need undertakes handling.

垂直搜索引擎是倒金字塔型，是对行业信息的梳理、再加工与编辑整理，是针对某一个行业的专业搜索引擎，是搜索引擎的细分和延伸，是对网页库中的某类专门的信息进行一次整合，定向分字段抽取出需要的数据进行处理后再以某种形式返回给用户。

Directional selection in disease field is the most simple, economic, and effective method for improving cotton resistance. Both land cotton and long-staple cotton high sensitive to the fusarium disease could improve its resistance in few years by this method and the farming properties were nearly unchanged.

试验证明，在供试材料中，不论是陆地棉的高感品种还是长绒棉的高感品种，经过在重病田或病圃中定向加压筛选，都可在几年内使其抗病性得到迅速提高，并保持其农艺性状基本不变。

Its thought is to change the model of the asynchronous motor through the coordinate, make it become direct current motor model, divided the electric current vector of the stator into according to the weight of two pieces of direct current with directional magnetic field of the rotor and controls, realize magnetism coherent and torque solve lotus root control , in the hope of the control result of the direct current reaching machine.

其思想就是将异步电动机的模型通过坐标变化，使之成直流电动机模型，将定子电流矢量分解为按转子磁场定向的两个直流分量并分别加以控制，从而实现磁通和转矩的解藕控制，以期达到直流电机的控制效果。

Biometrics ; automated fingerprint identification system; continuously distributed directional image/field; preprocessing of fingerprint image ; noise cleaning

生物识别技术；自动指纹识别系统；连续分布方向图；指纹图像预处理；去噪

On the one hand,Magnetic Polymer Microsphere could covalent active materials—enzymes,cells and antibodies;on the other hand,they could show strong magnetic responsibility for their directional movement in the magnetic field.

一方面磁性聚合物微球可通过共价键来结合酶、细胞和抗体等生物活性物质；另一方面因其具有"在外界磁场存在下能定向运动"这一特殊性能，可对外加磁场表现出强烈的磁响应性，因此它被用作酶、细胞、药物等的载体，广泛地应用到生物医学、细胞学和生物工程等领域。

Power dividers and directional couplers are passive devices used in the field of radio technology.

功率分频器和定向耦合器是无源器件在外地使用的无线电技术。

ABSTRACT Aiming at problems of trans-vector controller in a vehicle-carried induction motor such as variable rotor and stator resistance following motor temperature, and their inductance varying with flux saturation degrees. Firstly, CSI and VSI are introduced, for CSI, it can hold the advantages both FOC and DTC using stator flux directional, PI parameter and simulation are also introduced. Secondly, equations of IM in the synchronous rotary frame and its static counterpart, as figuring in the saturation condition of magnetic field, are dealt in this paper and the simulation results are presented. Thereafter, the parameter designing of PI trans-vector controller is processed, which features the non-linear model. In practical realization, as neglecting the dynamical change of motor inductance, this paper employs online modification of inductance parameters, according to the flux saturation, then transforms the non-linear equations into linear ones, and so compacts the structure of controller. Thirdly, in view of the maximum torque output is extraordinary requisite when Electrical Vehicle start up, accelerate, and overtake, this paper issues the maximum torque when both inverter and battery capacity is corporeally definite. Fourthly, on-line differentiating and analyzing both rotor's time constants and its flux by using the expanding order reduction and discrete Kalman filter equation are fathomed, in order to realize high-performance trans-vector algorithm, and also the simulation results are presented. Fifthly, the close-loop regenerative brake system, when the EV's torque is set constant, is deduced; at the same time, unification of electric drive model and brake model is executed. Combined with maximum charge current demands, the mathematical model for online yielding torque as a demand.

本论文针对车载异步电机在矢量控制器所遇到的问题：定转子电阻随温度变化及随电机饱和程度变化的转子电感及定子电感而影响电机调速性能提出一套完整的解决方案：分析了电流型逆变器和电压型逆变器在实现矢量控制时控制器参数的计算，分析出对于电流型逆变器在采用定子磁场定向时，其性能同时具有矢量控制和直接转矩控制两者的优势，并对电压型逆变器在转子磁场定向下的模型进行了仿真研究；建立异步电机非线性模型，推导出考虑磁饱和时异步电机在同步旋转坐标系及静止坐标系下的方程，并做出了仿真结果，建立异步电机在非线性模型下的矢量控制调节器的PI参数设计，在实际应用中，若忽略电机电感的动态变化，可以根据当前的磁路饱和状态而在线修正电感参数，从而将非线性方程线性化，降低控制器的复杂度；考虑到电动汽车在起动和加速超车时需要电机有最大转矩输出，本文讨论在逆变器容量一定和电池供电能力有限的情况下电机最大转矩输出问题；推导了异步电机扩展降阶、离散卡尔曼滤波方程在线辨识转子时间常数和转子磁通，用于实现高性能的矢量控制算法，并给出了仿真结果；推导出了电动汽车恒转矩给定的闭环回馈制动系统，实现了电动控制模型和制动模型的统一，而且结合铅酸电池最大充电电流的要求，为制动转矩在线给定建立了数学模型；设计了基于双DSP系统的高性能矢量控制器软硬件框图，并以大量实验数据说明矢量控制在电动汽车应用的实际应用状况。

When exterior magnetic field exists, Lorentz force compels originally directional moved electron excursing and electron accumulates on one side of semiconductor.

由于外部磁场的存在，洛伦兹力迫使原始电子做短距离的定向移动而累积在半导体的一边。

As the integrated product of computer technology, communication technology, instrument technology, and control technology, Fieldbus is one of the focuses of the current technical development in automatic field, Fieldbus is whole scattered, intelligent, bi-directional, interconnected, multivariable and multipoint communication network which connects intelligent working equipment with automatic system.

现场总线作为计算机技术、通信技术、仪表技术以及控制技术高度集成与综合的产物。已成为当今自动化领域技术发展的热点之一。它是连接智能现场设备和自动化系统的全分散、数字式、双向、多变量、多点、多站的通信网络。

The present invention relates to a method for heuristically starting up DC brushless servo electric machine, including the following steps of (1) after powerup of an increment type photoelectric encoder, electrifying a stator winding two by two with identical time interval to generate six-directional stator winding resultant magnetic fields;(2) detecting six different angles rotated by the rotor within identical tiny time interval by the photoelectric encoder;(3) selecting most positive value rotation angle from the six different angles, and determining maximum torque corresponding to the stator winding resultant magnetic field, and implementing servo startup using the maximum torque as constant starting torque;(4) after the zero-point signal of the photoelectric encoder occurring, switching to servo operation with normal constant torsion.

本发明直流无刷伺服电机试探启动方法，采用如下步骤：(1)增量式光电编码器上电后对定子绕组采用相同的时间间隔两两通电，顺序产生六个方向的定子绕组合成磁场；(2)由增量式光电编码器检测出转子在相同的微小时间间隔内分别转过的六个不同的角度；(3)从转子六个不同的角度中选出最大正值的转角，确定相应定子绕组合成磁场对应的最大转矩，并以该最大转矩为恒定启动转矩进行伺服启动；(4)当增量式光电编码器零点信号出现后，切换为正常恒转矩伺服运行。

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。