电流

The article focuses on the teaching of circuitry,from the basic concept,discusses the direction of the voltage or the electric current in different situations such as Ohm′s law,Kirchhoff′s law,Superposition theorem and so on.

结合在多年的教学，本文针对不同的情况电压和电流的方向做了探讨。1电流电压的实际方向和参考方向习惯上把电流的方向定义为正电荷运动的方向或负电荷运动的相反方向，而把电压的实际方向定义为电位降的方向。

Kirchhoff's Current Law tells us that the algebraic sum of currents entering and exiting a node must equal zero, so we can relate these three currents (I1, I2, and I3) to each other in a single equation.

基尔霍夫电流定律告诉我们，进入和流出一个节点的电流代数和必定等于零，因此我们可以在一个方程式中建立起这三股电流I1， I2， and I3的相互关系。

Finally, according to voltage with compute the electric current choose once equipments, including circuit breaker, insulate the switch, fuse, voltage transformer, current transformer, lightning arrester, busbar and electric cable and so on, then according to compute the result of the short-circuit electric current with designs the request to once equipments proceed check to break the ability of flowing and stable degrees of short circuit about moving and hot.

最后，根据电压和计算电流选择一次设备，包括断路器、隔离开关、熔断器、电压互感器、电流互感器、避雷器、母线和电缆等，再根据短路电流计算结果和设计要求对一次设备进行断流能力和短路动稳定度、热稳定度的校验。

Therefore,it is of great importance to measure the linear birefringence inside the optical current sensing head for the property enhancement of the optical current sensors.

线性双折射是光学电流传感头的重要光学参量之一，会明显影响光学电流传感器的性能，因此测量光学传感头内线性双折射的大小对于提高光学电流传感器的性能有重要意义。

To overcome these drawbacks, the application of current mode tri-state modulation technology to the switching power amplifier for magnetic bearings is proposed, as well as its special advantages.

文中首先分析了电流纹波对磁轴承系统的影响，接着分析了电流两态调制技术本身的固有不足及电流三态调制技术在磁轴承开关功放应用中的优势。

To improve accuracy of detection of current direction, components of magnetizing current and torque current are transformed into two-phase stationary frame. Therefore compensating voltage vector can be decided according to the sector the current vector is locating.

为了提高电流极性检测的准确性，利用旋转轴系中的励磁电流和转矩电流分量经过坐标反变换，判断电流在两相静止轴系所处的扇区来决定需要施加的补偿电压。

Its output current can be continuously adjusted from zero to two hundred milliamperes and its stability reaches 1.5×10-5. The variation of the output current is less than 1μA when its operation time is longer than 12h. The modulation of frequency and intensity of optical wave in the laser interferometry can be achieved by the modulated current (100kHz～300kHz) input, whose modulation depth is continuously adjustable from zero to one hundred milliampere.

该电路的直流稳定度高达1.5×10-5，输出电流在0～200mA内连续可调，长时间工作（12h以上）电流变化小于1μA；在直流基础上注入100kHz～300kHz的调制电流，其调制深度为0～100mA连续可调，可实现在激光干涉测量中对光波频率和光波强度的调制。

Secondly, contraposes the limitation of the traditional harmonic current detecting method based on neural network, presents the method that combines the neural network and auto adaptive harmonic current detecting method based on the principle of noise each other eliminating.As the characteristics that are small calculative quantity, fast converge, without local minimal point of Redial Basis Function, this dissertation forms a new harmonic current detecting method based on RBF.

其次，针对传统的谐波电流检测方法的缺陷，提出将神经网络与基于噪声抵消原理的自适应谐波检测相结合，利用径向基函数运算量小、收敛快、无局部极小值等优点，构造了一种基于径向基函数神经网络的谐波电流检测方法，仿真结果表明该检测方法具有很好的动态响应及畸变电流检测精度。

SURGE CURRENT Surge current is specified as the maximum allowable peak, nonrecurrent squarewave current with a pulse width, PW, of 8.3 ms.

浪涌电流的浪涌电流的最大允许指定为高峰期，非经常性方波脉冲宽度，星期三8.3毫秒，电流。

Impulse current: Current to be used in the test for surge current resistibility of optical fibre cables.

脉冲电流测试光缆对浪涌电流。耐受能力时使用的电流。

I will endeavour to find you some assistance.

我尽力帮你找人帮忙。

At first I only know bruck is the idol of American younglings, afterwards I returned back to Taiwan ,even in Beijing last year ,I saw her poster everywhere, I was so surprised at her charm.

起初我只晓得布鲁克雷德丝是美国少男少女崇拜的偶像，后来回台湾，甚至去年在北京，居然也四处看见她的海报，才惊讶她的魅力之大。