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- Energy consumption of variable frequency drive pump are analyzed,and makes sugg estions about its suitable application. 详细分析了变频调速水泵的能耗，对如何合理应用变频调速水泵进行了探讨。
- The microcontroller then sets the frequency driving AOM to let the shifted optical frequency to jump alternatively to either side of the desired saturated absorption peak. 单片机控制AOM在吸收峰左右跳频得到鉴频信号，经数字PID计算反馈控制激光频率，实现了无调制稳频。
- E.Division 15 Contractor shall furnish all adjustable frequency drive controllers (AFD's, also commonly referred to as VFD's) unless AFD's are located in a motor control center. 承包商应提供所有可调频率驱动控制器（简称AFD，通常也成为VFD），除非这些可调频驱动控制器也安装在电机控制室/中心。
- Products include reduced voltage starting controllers, variable frequency drive controllers, bubbler systems and systems utilizing programmable controllers. 这些产品包括减压启动控制装置，变频驱动控制装置，喷水系统，以及采用可编程序的控制装置系统。
- Analyzing the performance curves of pumps and network in a variable flow pumping system, concluding the influence factors of energy saving and the optimal ranges of variable frequency drive (VFD). 摘要通过分析变频水泵及管网系统在变工况下的特性曲线，得出影响水泵变频节能效果的主要因素和变频调速的适用范围。
- Brillouin enhanced four wave mixing, whose interference beat frequency drives an acoustic field, can improve the SBS phase conjugation fidelity. 采用四波混频加强SBS的方法，其相干拍频驱动声子场，能提高SBS相位共轭保真度。
- wide audio - frequency driving vibration loading 宽音频激振加载
- variable frequency driving (VFD) 变频驱动
- Door machine variable frequency drive 门机变频驱动
- Rotor-side variable frequency drive system 转子变频
- high power repetition frequency drive source 高功率重复频率脉冲驱动源
- high-voltage variable frequency drive 高压变频器
- variable frequency drive water supply system 变频给水系统
- He varied the transmission frequency. 他变换了无线电传送的频率。
- A unit of frequency equal to one cycle per second. 赫兹频率的单位，等于每秒一周
- A High Frequency Driving Circuit of IGBT for Full Bridge Converter 一种适用于桥式变换器的IGBT高频驱动电路
- Fatal accidents have decreased in frequency over recent years. 近年来死亡事故发生的频率已经下降。
- We can often correlate age with frequency of illness. 年龄的大小往往与发病率有关。
- Accidents on that highway are happening with increasing frequency. 那条高速公路上车祸发生得越来越频繁。
- A variable frequency drive system based on SPWM for fan or pump 风机水泵负载SPWM交流变频调速系统的研究
