和电路

The tendency of chemical elements with similar positions in the periodic table to have similar properties.

一种提供周期性信号的电路，用于控制和同步其它电路。

Compared to the ordinary PLL circuits, it can endure the short time appearance that occurs once in a horizontal line of the sync signal. It can adapt to the phase alternation character of a PAL video signal and recognize the phase alternation line. The local color sub-carrier can be generated for synchronous demodulation by the circuit.

该电路使用了全数字锁相环对色同步信号进行跟踪，与普通锁相环电路相比，它不仅能适应制视频信号中色同步信号每行出现一次和PAL制信号逐行倒相的特性，还能识别倒相开关信号，准确地产生本地色副载波用于同步解调。

The operating principle and hardware configuration of the instrument based on AT89C51 for testing breakdown voltage of the dielectric oil is introduced. The method to collect the breakout current through photoelectric isolation is proved when the dielectric oil was broken out. The question about the system work stability in the condition of strive electromagnetism interfere is proposed.

介绍了 AT89C5 1单片机控制的绝缘油耐压测试仪的工作原理及硬件结构，探讨了在绝缘油击穿时，通过光电隔离采集击穿电流的方法，解决了在高压击穿瞬间和强电磁场干扰环境下，微机电路实行有效复位并使系统稳定工作的问题，给出了基于 MAX70 6为核心的高可靠复位电路的实现方法。

Transformer or phototube of coupling is used to separate control electro circuit and main electro circuit.

该电源采用脉宽技术，控制电路和主电路之间通过变压器或光电耦合器进行隔离。

In this paper,traditional H-bridge circuit for Electric Power Steering System was introduced and analysed.

对智能功率开关的功能特性和采用智能功率开关组成的H桥电路的控制方法与工作原理进行了系统研究，并在试验台上对新的H桥驱动电路进行了试验验证。

Research on design and reality of the power supply.

电源主电路和驱动电路的设计与实现。

This design are composed of pre-amplifier, after-amplifier, and the modules of display and control based on microcontroler.

本设计由前级放大电路、后级放大电路和单片机显示与控制模块构成。

An analysis of noise models for two basic pre-amplifier structures:voltage and transimpedance are carried out.

如何降低电路噪声是读出电路研究热点之一，本文就红外探测器的电压型和跨导型两种基本结构前置放大器，建立了噪声等价模型，分析比较了其信噪比。

Since the output signal from fringing field dielectrometry sensors under a low frequency driving voltage are very low, the shield-drive, signal buffer and band-pass filter are adopted to improve SNR. With the signal gain and phase angle from a transform circuit, the complex permittivity of pressboard are obtained.

鉴于边缘场电容式传感器在低频正弦驱动信号作用下输出的感应信号非常微弱，调理电路采用驱动屏蔽方式进行测量信号缓冲，用带阻滤波器提高信噪比，并利用相应的变换电路求出电容系统的相位角和幅值增益，从而得到绝缘纸板的复介电常数。

The design scheme of power circuit and the choice principle of periphery circuit component are introduced in detail.

详细介绍电路设计方案和外围电路元件的选择，实现手持设备使用2节普通碱性电池升压供电。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。