大功率的

A new model of vacuum tube was described in the paper, using this model some simulation was made.

并通过对大功率三极管的建模，运用PSPICE软件进行了仿真实践，该仿真的结果证明了该仿真模型是可行的，并且为实际系统的实验分析提供了理论上的指导。

A home made spray system was used on insecticide experiment on parasitic wasp, Anastatus japonicus Ashmead. This system was associated with bioclimatic chambers to provid a series simulated farm conditions for the experiment of testing the insecticide toxicity on A.

根据生产的需要，研制实用仿真农药喷雾实验系统，配以一定数量的大功率人工设备，并以几种典型的常用农药为例，探讨荔枝蝽卵平腹小蜂在仿真喷雾条件下死亡率与农药田间使用浓度的再稀释浓度的关系。

The digital high power system based on constant RMS, can adapt to various constant voltage or current application. One application is installed in the air exhauster to control the process of producing the tube of energy-saving lamp.

中文摘要：基于有效值恒定的大功率数字电源系统，具有非常广泛的应用范围，可以适用于各种需要有效值恒定的恒压和恒流电源的场合，如应用在生产节能灯管的排气机——长排车上，用于控制节能灯管的排气过程。

Traditional three phase three legsinverter can provide relative good performance. However it will be ineffectivewhen it is connected to non-linear unbalanced loads which are often used invital occasion such as military, bank, hospital and so on.

传统的三相三桥臂逆变器虽然能提供较大功率，但是由于非线性不平衡负载的普遍存在，而且这些非线性不平衡负载往往出现在非常重要的场合，如：军事、银行、医院等要求电能质量很高的领域，此时传统的三相三桥臂逆变器显得无能为力。

At this point, control circuit control high-power switch will be presented in a high-voltage direct-current high-frequency batch sent to high-frequency transformer primary and went on to the secondary loop after ventriclar hifrequency rectifter-voltage alternating current, by filtering is converted to a low-voltage stoichiometrical DC.

此时，控制电路控制大功率开关将高压直流电按照一定的高频频率分批送到高频变压器的初级，接着把从次级线圈输出的降压后的高频低压交流电，通过整流滤波转换为低电压强电流的直流电。

to overcome some disadvantages of low precision,slow dynamic response,unconvenience parameter adjust existing in high-power ultrasonic power supply,it applies intelligent control composed of 8089 microcontroller is proposed.the article introduces the modulation principle of spwm,the composition of high-power ultrasonic power system applying the single chip computer to realize the soft of phase lock loop,the mechanism of work and the software thought.it realizes the low loss,high power factor and the whole performance of the circuit is developed.

寂寞网民何时&回家吃饭&？基于单片机8089的超声波电源控制技术的研究。裴玖玲屈百达□摘要：针对目前大功率超声波电源采用模拟控制电路存在精度低、动态响应慢、参数整定不方便等缺点，采用单片机8089组成智能控制的超声波电源系统。提出了基于spwm技术的双闭环控制策略和应用单片机实现软锁相的工作原理和软件思想，使整个超声波电源实现了低损耗、高功率因数，优化了电路的整体性能。

With the development of belt conveyor towards long distance,high speed,long caning capacity and large driving power,the effect of the dynamic property on belt conveyor is becoming more and more important.

随着带式输送机向长距离、高速度、大功率方向发展，胶带机在运行过程中的非稳定运行工况下的动力特性对带式输送机的影响日益突出，尤其在胶带机启动和制动过渡过程中，胶带机中的张力变化的复杂性会严重影响胶带机的寿命。

According to that the middle long range develops a plan, will establish the heavy ion nuclear physics step by step rolling a cluster into a ball with hadron physics , atom and molecule physics , ion irradiation living things material, and the advanced ion accelerator wait for the distinct five characteristic countries laboratory (including that the ion beam administering cancer), resisting an irradiation with high-power electron accelerator; Be that China participates in the international antiproton and the ion studies the device Big Science project scientific and technological cooperation coordination unit; The significant country "the 9th Five-Year Plan" science project "Lanzhou heavy ion cooling being completed soon stores up the ring" general

按照中长期发展规划，将逐步建成重离子核物理与强子物理、原子与分子团簇物理、离子辐照生物、抗辐照材料、以及先进的离子加速器与大功率电子加速器等五个特色鲜明的国家实验室；是中国参与国际反质子与离子研究装置大科学工程科技合作的协调单位；即将竣工的国家&九五&重大科学工程&兰州重离子冷却储存环&将作为国家重要的公共研究平台对国内外开放。

This paper analyzes the working characteristic of parallel running system and indicates the problems existing in non- parallel running pump or fan.

本文分析了并联运行系统的工作特性，指出了泵或风机非同步运行存在的问题；大功率应用领域采用偶合器调速是一类适宜的调节方式，在分析偶合器调节特性的基础上，给出了一种实用的同步调速控制方法。

Combined with practical work in Liuxiang trade city in Taiyuan, in view of the faults of high power gas discharge lamp the causing reasons are analyzed from three aspects: starting condition, working pressure and supporting equipments.

摘 要：结合太原柳巷商城的工程案例，从大功率气体放电灯的故障入手，从灯的启辉情况、工作管压、配套工作件三方面分析了故障的原因，指出这些原因在系统配套件的作用下引发故障的真相。

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。