电流

This paper proposes a novel current control stratege to avoid this unstable. The grid current feedback is used controlled the power factor expediently, and a second differential link of grid current is designed to stabilize the system.

本文采用了一种新型的电流内环控制策略，该策略采取了电网侧电流反馈控制，能够方便的控制功率因数，在电流内环引入了电网电流二次微分来解决不稳定的问题。

Two kinds of silicon samples with distinct surface treatment, i. e., one surface was chemically etched and the other was unetched, were used to investigate the characteristics of leakage current and surface flashover of semiconductor under impulse voltage in vacuum. The experimental results showed that the surface conditions of samples affected these characteristics greatly. Before flashover, the Ohmic current was observed for unetched samples and the space charge limited current for etched samples, respectively. Meanwhile both samples showed quite different flashover tracks, and the surface-etched samples displayed a much higher onset voltage of flashover.

对采用和未采用表面化学腐蚀处理的半导体硅在冲击电压下的实验表明（参见 Zhang et al ， Applied Physics Letters， 2002），试品的表面状况对其泄漏电流和沿面闪络特性有着很大的影响：在沿面闪络之前，未经处理试品的泄漏电流表现为 Ohm 性电流，而表面处理过的试品表现为空间电荷限制电流特性；同时两类试品表面的闪络通道也表现出不同的特征，而采用表面化学腐蚀处理可以明显提高其沿面闪络电压。

The results showed that the W content in the electrodeposits rose with the increasing of cathodic current density in the solution containing ammounium citrate as complexing agent,whereas the current efficiency remained approximately constant. When the current denisity was higher than 15 A/dm2, the W content in the alloy was not obviously changed, but the current efficiency remarkably decreased.

结果表明，在以柠檬酸铵为络合剂的镀液中，沉积层的W含量随电流密度的增大而增加但电流效率变化不大，当电流密度超过15A/dm2后，镀层的W含量不再发生明显的变化而电流效率却明显降低。

The frequencies of the pacemaker currents from gastric and small intestinal ICC are very similar to the frequencies of rhythmic contraction in murine gastric and small intestinal smooth muscles; ICC network generates higher- amplitude, stabler and more rhythmic pacemaker currents than single ICC does; low concentration of intracellular free calcium is an important factor for generating pacemaker current; calmodulin is involved in the inhibitory regulation of the pacemaker current.

小鼠胃和小肠ICC产生的起搏电流频率与小鼠胃和小肠自律运动的频率非常接近；网络ICC产生的起搏电流比单个ICC稳定、幅度高、频率快； ICC内游离钙浓度的降低是产生起搏电流的重要因素；钙调蛋白在ICC内参与起搏电流的抑制性调节。

Current distribution was measured by shunts with current multiplex method connected to the corresponding segments.

电流分布量测是使用电流多通传输法，将电流分流器连接至相对应的区域以测量电流。

Is shown in Figure 4-15. The picoammeter reads the current at the last dynode, which is equal to the anode current minus the current flowing to the previous dynode.

皮安计在最后一个倍增管电极处读取电流，此电流等于阳极电流减去流过前一个倍增管电极的电流。

Due to capacity increase or structure change of the power system, an extra-high current possibly 100 times of the rated current may appear in some circuits of the power system when a short-circuit fault happens nearby. This current is extra high and exceeds the permitted value of 10% error curve of protection current transformer.

在电力系统中，各回路的最大故障短路电流和额定工作电流的比值应在合理的范围内，以保证保护用电流互感器的工作精度，但由于系统容量增大或因系统结构等原因，某些回路在某些情况下的最大故障短路电流远远超过了正常范围。

And the individual compensation current is the product of the harmonic component extracted from the filter current and the compensation factor generated by the harmonic phase regulator.

总补偿电流是待抑制的各次谐波补偿电流之和，而各次谐波补偿电流是滤波器电流中的谐波分量与谐波相位调节器输出的补偿系数之积。

Through the analysis of the work principle of three phases voltage resource PWM converter, set up the low and high mathematic models, deduce the restriction equations about grid voltage, grid current, modulation voltage and the DC output voltage and the calculation equations of the AC-side inductance and the DC-side capacitance. There are two control strategies are adopted: Predicted current control strategy and voltage-current two closed-loop control strategy, and give a comparison by theory and practice.

通过分析三相电压源型PWM变换器的工作原理，分别分析了低频和高频数学模型，并推导出了交流侧电压电流、调制电压、直流侧电压之间的数学约束关系以及交流侧电感和直流支撑电容参数的选取依据公式；分析对比了两种控制策略：预测电流控制和电压电流双闭环控制并加以实验验证；同时采用了负载电流前馈补偿和本文提出的一种基于专家系统的神经元新型智能PI控制器两种方法大大提高了整个系统的动态响应性能，并在仿真和实验中加以验证，这也是本文研究的重点内容之一。

Operational Tran conductance lifers and Grounded actorhas become one of the most important methods to implement integrated continuous-time filters. Operational Tran conductance Amplifierscan transfer input voltage into current to output,and control or change output current within large range by an external controlling current of amplifier. Most articles consider OTA as a voltage-mode circuit component and give voltage-to-voltage transfer function of all having been implemented filter circuits,i.e. The input signal and output signal of filter circuits are voltages .

运算跨导集成运算放大器OTA ( Operational Tran conductance Amplifier 以下简称跨导运放)的功能是将输入电压转换为电流输出，并通过外加偏置电流控制运放的工作电流，从而使它的输出电流在较大范围内变化，而在大多数文献中，器件都被作为电压模式元器件使用实现的各种滤波电路都是按传送电压比给出的，即滤波电路输入信号和输出信号均为电压信号。

The absorption and distribution of chromium were studied in ryeusing nutrient culture technique and pot experiment.

采用不同浓度K2CrO4(0，0.4，0.8和1.2 mmol/L)的Hoagland营养液处理黑麦幼苗，测定铬在黑麦体内的亚细胞分布、铬化学形态及不同部位的积累。

By analyzing theory foundation of mathematical morphology in the digital image processing, researching morphology arithmetic of the binary Image, discussing two basic forms for the least structure element: dilation and erosion.

通过分析数学形态学在图像中的理论基础，研究二值图像的形态分析算法，探讨最小结构元素的两种基本形态：膨胀和腐蚀；分析了数学形态学复杂算法的基本原理，把数学形态学的部分并行处理理念引入到家实际应用中。