高频

The hardware consists of industrial personal computer, temperature data collecting module, analog output card and thermocouples. With Visual Basic6.0 as a development platform, the software is based on control algorithm.

其温度控制通常是通过高频加热设备上的手动旋钮调节输出功率，从而控制温度，这样很难达到精确控制试验样品的升降温速度和进行恒温控制，本文设计一套高频感应加热设备温度控制系统，控制界面友好，可以直接在计算机上设定高频感应加热设备的温度变化曲线。

The foundation of this system provides a good reference to promote the standardization and intelligence of the overhaul and maintenance of vacuum switches. This paper develops a special HF pulse power supply for internal pressure estimation, which achieves the output of HF-HV sinusoidal pulse wave whose frequency and amplitude can be modified respectively, and meets the design requirements according to the results of Simulink simulation and practical experiments. With the help of AT89S52, this paper designs an I~2C serial bus based signal detection system for peak value signal acquisition of HF pulse currents, which communicates with the upper computer by asynchronous serial communication for uploading the data. In the upper computer, a human computer interface is developed by Matlab software, whose functions are to do some computation and graphic display, such as calibrating the relation curve of vacuum degree and peak value of HF pulse currents, vacuum degree computation, and vacuum lifetime evaluation analysis basing on grey forecasting model as well as making relative suggestions.

本文研制了用于真空度检测的高频脉冲电源，通过Simulink仿真和试验检验其满足设计要求，实现了电压幅值和频率独立可调的正弦波高频高压脉冲输出；利用以AT89S52为核心基于I~2C串行总线的信号检测系统实现高频脉冲电流峰值信号的采集，通过异步串行通信实现单片机与计算机之间的数据通信，将检测数据传至上位机；在上位机利用Matlab开发人机交互界面，实现相关数据处理和图形显示，包括真空度——高频脉冲电流峰值关系曲线标定、真空度数值计算、基于灰色预测模型的真空寿命评估分析和提出相应决策建议。

The radio knife is high frequency power equipment based on the theory that electricity concentrates on the skin. It can directly cut the tissue, homeostasis and cauterize. The safety requirement of this equipment is very strict because unsafe operation will burn the tissue, cause temporal unaware hurt and even endanger the patient's life.

高频电刀是利用高频电流的"集肤效应"原理，使高频电流对人体组织直接进行切割、止血或烧灼的一种高频大功率电器设备，故其安全性要求极为严格，一旦出现安全问题，将出现灼伤，还可能造成一些暂时难以觉察的影响，甚至导致生命危险。

The high-frequency response characters of a simple-supported beam is obtained by NASTRAN.The result is strongly influenced by the mesh size.The comparison based on FEM,SEA and the closed form solution reveals the effectiveness of SEA in the prediction of high-frequency response.

利用NASTRAN软件得到一简支梁从低频到高频的频响特性，研究了不同有限元网格划分对结构高频特性的影响，并通过SEA法、有法元法以及解析解的对比揭示了SEA法在高频响应预示中的有效性。

The invention relates to an amplifier circuit containing a high-frequency transistor (1) and having a circuit (2) for adjusting the operating point, which provides a base current for the high-frequency transistor (1) according to the voltage released at a resistor (3) which is connected in the collector ring of the high-frequency transistor (1). The circuit (2) has a differentiating unit (20), fed by the supply voltage, which compares the voltage released at the resistor (3) with a reference voltage.

带有高频晶体管(1)的放大器电路具有一个用于工作点调整的电路(2)，其依赖于在连接在高频晶体管(1)的集电极电路中的电阻(3)上下降的电压为高频晶体管(1)提供基极电流，电路(2)具有一个由供电电压馈电的差分节(20)，其把在电阻(3)上下降的电压与基准电压比较。

It is found in field detection that ultra high frequency signals can diffract from the joint of transformer. The feasibility of using external UHF sensor for detecting partial discharge activities is discussed, and the external propagation characteristic of UHF electromagnetic wave is investigated via the lab experiment.

针对变压器箱体的接缝处可以衍射出局部放电特高频电磁波信号的现象，在分析变压器箱体接缝对局部放电特高频电磁波传播影响的基础上，探讨了接收天线外部检测特高频信号的可行性，并通过实验研究了局部放电特高频电磁波的外传播特性，通过对信号进行小波包分析，比较了外部接收和内部接收信号的差异。

Results: The results showed that the prevalence of HFNIHL in riveters, in various ranges from 0.25 kHz to 8 kHz and in work history were significantly higher than those of test pilots; and the prevalence of HFNIHL in riveters was different in different gender. Conclusion: The aircraft-made noise can dramatically injure workers' auditory system, especially showed in high frequence.

结果：铆工高频损伤耳数和电测听各频率异常耳数与试飞员比较差异有统计学意义；两工种高频损伤耳数与语频损伤比较差异有统计学意义；两工种不同工龄段，高频损伤耳数与语频损伤比较差异有统计学意义；铆工中男性高频损伤与女性比较差异有统计学意义。

The radio knife is high frequency power equipment based on the theory that electricity concentrates on the skin. It can directly cut the tissue, homeostasis and cauterize. The safety requirement of this equipment is very strict because unsafe operation will burn the tissue, cause temporal unaware hurt and even endanger the patient's life.

高频电刀是利用高频电流的&集肤效应&原理，使高频电流对人体组织直接进行切割、止血或烧灼的一种高频大功率电器设备，故其安全性要求极为严格，一旦出现安全问题，将出现灼伤，还可能造成一些暂时难以觉察的影响，甚至导致生命危险。

In addition, the analyses of weld surface ripple and microstructure with three current waveforms have indicated that the high frequency wave group modulated by low frequency GTA welding has the advantage of both the low frequency in which the heat input of the weld pool is easily controlled and high frequency GTA welding in which the arc is energy—concentrated and stiff.

另外，通过对高频脉冲焊、低频脉冲焊、低频调制高频方波群焊不锈钢焊缝表面形貌分析表明，低频调制高频方波群焊综合了低、高频GTA焊的特点。

The three-dimensional models are successfully imported to ADAMS software through the special interface MECH/PRO, and then the virtual prototype models are founded by toolbox of ADAMS to apply forces and constraints to the parts of the models. The dynamic simulation of the multi-rigid-body rifle model is carried out under the condition of the single shoot by the low firing frequency, high firing frequency and superhigh firing frequency when the rifle model is fixed on the ground, then the dynamic simulation of the multi-rigid-body man-weapon system is operated under the conditions of single and repeating shoots.

通过Pro／E和ADAMS的接口MECH／PRO将三维实体模型顺利导入ADAMS中，并对高频点射步枪和人枪系统施加约束和力，建立高频点射步枪和人枪系统的虚拟样机模型，并且对高频点射步枪及人枪系统进行了较为系统的多刚体系统动力学分析和研究，分别对高频点射步枪固定状态下次高频、高频和超高频点射过程进行了多刚体系统动力学的仿真，在此基础上对高频点射步枪人枪系统点射和连发进行了仿真。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐