查询词典 direct current

The mechanism is composed of two ball screws, U-type linear rails, linear bearings and flexible couplings. The permanent magnetic direct current motors are used as actuators. The rotary encoder is used to measure the angular position of the DC motor. The digital controller is implemented on the personal computer and a motion control card (EPCIO-6000). The objective of this thesis is to realize precise positioning control using a real-time motion control system on an X-Y table.

机械结构包括有滚珠导螺杆、U型线性滑轨组、线性轴承及可挠性连轴器等；致动器是采用永磁式直流马达(permanent magnetic direct current motor)；感测器是使用光学式旋转型编码器来量测马达旋转的角度；控制器则是以个人电脑为控制核心，搭配运动控制轴卡(EPCIO-6000)所组成。

This design separately uses series linear constant voltage circuit, series regulate constant current circuit and the feedback type contravariant circuit to design direct current constant voltage power supply, direct current constant current power supply and DC-DC converter.

本设计分别用串联型线性稳压电路，串联调整式稳流电路和反馈式逆变电路设计直流稳压电源，直流稳流电源和DC-DC变换器。

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。

Direct current is rejected: When the electricity owes and presses the trouble in the city, it will be too automatic to supply power disconnectedly at all that the direct current of connecting with end of direct current is rejected, direct current rejects and can provide the signal while discharging, if discharge to the terminal voltage, will change over to and prepare against the electricity to run in system, while closing to stopping discharging the voltage, the system will provide the signal of warning.

直流屏：在市电欠压或故障时，与直流端相联的直流屏就会自动毫无间断地供电，直流屏放电时会给出信号，如果放电至极限电压，系统就会转入备电运行，在接近终止放电电压时，系统将给出警示信号。

This thesis calculates emphases the excitor circult of AC excitor .but the calculate of excitor circult must solve two problem: how to caculate the output AC phasic potential, phasic electric current and the capacity of AC excitor basing on the main generator direct current excitating voltage and direct current excitation current ;how to caculate the armature feedback, power factor and required ampere-turn of AC exciter.

本文重点对交流励磁机的磁路进行计算，但磁路计算先要解决两个问题：如何根据主发电机给定的直流励磁电压和直流励磁电流计算出交流励磁机的输出交流相电势，相电流及交流励磁机容量；如何计算交流励磁机的电枢反应，功率因数及其所需的安匝数。

Then introduce the principle of work and the construction characteristic. This thesis calculates emphases the excitor circult of AC excitor .but the calculate of excitor circult must solve two problem: how to caculate the output AC phasic potential, phasic electric current and the capacity of AC excitor basing on the main generator direct current excitating voltage and direct current excitation current ;how to caculate the armature feedback, power factor and required ampere-turn of AC exciter.

本文重点对交流励磁机的磁路进行计算，但磁路计算先要解决两个问题：如何根据主发电机给定的直流励磁电压和直流励磁电流计算出交流励磁机的输出交流相电势，相电流及交流励磁机容量；如何计算交流励磁机的电枢反应，功率因数及其所需的安匝数。

This dissertation theoretically demonstrates the feasibility to achieve constant direct current-stimulation-circuitry under microampere , bring forward design scheme software and hardware system using in cellular electrical stimulation. In order to further quantitatively research on direct current-stimulation and ascertain the best intensity and density and stimulative current , the quantitative and qualitative analyse for gained diagnostic data are also been discussed in this paper.

本文正是从该理论基础出发，论证了实现微安级直流电刺激的离体组织细胞生长培养实验系统的可行性，提出了用于刺激实验的软硬件系统的开发放案，并对采集数据的定量和定性的分析作了初步的探讨，希望通过实验能够初步确定适合该组织细胞生长培养的最佳刺激电流和最佳刺激时间。

By using the measure and research of the emulating two-port network parameters of using direct-current analysis and figure value output function of sinusoidal steady state circuit in circuit emulating sofeware PSPICE8.0,the measune and reseavch have solved the problem of the measuring purely resistive network of simple and odd one in traditional experimient,and also brought about the analysis of alternating current and direct-current for two-port network of any one complex and measure and research of Y、Z、T、...

利用电路仿真软件PSPICE8.0中直流分析及正弦稳态电路的数值输出功能仿真二端口网络参数的测量与研究，解决了传统实验中只能测量简单、单一的纯电阻网络问题，实现了对任一复杂二端口网络交、直流的分析及Y、Z、T、H等参数的测量与研究，为更多的不易完成的传统实验以及复杂电路的分析研究开辟了一条新路。

Is coaxial actuates a alternator based on Simens PLC and its the network direct current velocity modulation system by a direct current motor, the direct current motor to actuate with the direct current velometer and to be loaded with revolves the encoder examination rotational speed; The generator electricity generation voltage after the numeral demonstrated the table demonstrated and delivers to the PLC simulation quantity load module.

在工业控制过程中，继电接触器控制系统因其没有运算、处理、通讯等功能，而不能完成复杂的控制方式，20世纪60年代PLC控制系统应运而生，它综合了计算机技术、自动控制技术和通信技术等现代科技，是当今工业自动控制的标准设备之一；70年代以后，又相继出现了集散控制系统DCS、现场总线控制系统FCS，现在以及今后很长一段时间内会是三种控制方式并存的局面，在这一背景下该文分析PLC控制的现状及发展前景。

Because of its fast and flexible controllability, the voltage source converter based high voltage direct current will be widely applied in power systems, so it is of practical significance to study the dynamic performance of VSC-HVDC in complicated power grids. The quasi steady state response of flexible HVDC system can be simulated in power system simulation software PSS/E.

柔性直流输电系统(voltage sourced converters high voltage direct current，VSC-HVDC)因其快速灵活的可控性在电力工业中将有越来越广泛的应用，研究其在复杂电力网络中的动态性能具有工程实际意义，应用电力系统仿真软件PSS/E可模拟柔性直流输电的准稳态响应。

By the time of its fall, most of the prisoners were writers who had written against the corruptions of the government.

到它被攻陷的时候，里面多数的犯人是写了反对政府贪污文章的作家。

The most obvious variation to ovum morphological character was that the color was changed from light green to sepiaceous in embryonic development, and all the ovums were almost hatched after 96h.

在胚胎发育过程中卵的形态特征最明显的变化是颜色从淡绿到深褐色，卵在发育96h后卵基本全部孵化。