查询词典 pi

Hysteretic-current-loop PWM invertor is its main circuit.

转速闭环采用带限幅的PI调节器，主电路采用电流滞环控制PWM逆变器。

In some experiments, flow cytometry analysis with Propidium Iodide was used to determine the rate of cell apoptosis.

一些实验中还运用了碘化丙啶(Propidium iodide， PI)染色流式细胞术检测细胞的凋亡率。

The thesis contains five chapters. The first chapter summarizes the development and research of switched reluctance drive, discusses the main research direction, and explains the main work in this paper. In chapter 2, hardware system which includes the design of power converter and various control circuit is discussed. TMS320LF2407 DSP is used to design the hardware circuits of SRM control system, and design details including the current detection, position sensing, fault protection, speed detecting, keyboard and display etc. are provided. Because of the full use of the abundant peripheral resources of DSP, it comes to the aim simplifying the circuit structure and heightening the reliability. In chapter 3, the application of neural network on SRM control system is introduced, a new the application of neural network and the method of sampling is proposed and a simulation system based on Matlab/Simulink is established. Chapter 4 discusses the routine designing issue. Because the modularized programming method is adopted, and multi-interrupt processing technique is used, operation efficiency of the control software is highly raised. At last, the foregoing SRM control system is tested. Speed adjustment is realized, and other targets on the research and design of SRM control system are reached, which establishes a good foundation for further research.

本文共分五章，第一章概述了开关磁阻电机调速系统(Switched Reluctance Drive，简称SRD)及其发展和研究现状，论述了其主要研究方向，并说明了本文的主要工作；接下来的一章主要讨论了SRM的硬件系统，主要包括功率变换器的设计和各种控制电路的设计，本文以TMS320LF2407为核心设计了开关磁阻电机控制系统硬件电路，给出了包括电流检测、位置检测、故障保护、测速电路及键盘和显示电路等部分电路的详细设计，充分利用了DSP的丰富外设资源，达到了简化电路结构、提高运行可靠性的目的；第三章介绍了人工神经网络在开关磁阻电机控制系统中的应用，提出了一种新的应用方式(利用GPFN神经网络调节PI参数)以及如何采取样本，搭建了基于Matlab/Simulink的仿真系统；在第四章中，讨论了开关磁阻电机控制软件的设计，采用模块化编程方法，采用基于多中断的控制程序，提高了控制软件的效率；最后，对所设计的开关磁阻电机控制系统进行了实验，实现了电机调速，达到了开关磁阻电机控制系统研究和设计的预期目标，为更近一步研究打下了基础。

Advances in research on the role of phosphatidylinositol-3 kinase in the pathogenesis of nonalcoholic fatty liver disease.

PI-3K在非酒精性脂肪性肝病发病中作用的研究进展。

Anyone who has ever studied geometry knows the importance of the quantity known as "pi".

任何学过几何学的人都知道圆周率这个数值的重要性。

The magnitude of opened angle at a point pi in the contour can be easily calculated by the law of cosines, and its local extreme correspond to the sharper changes of the contour of the mode.

其轮廓上点p处的张角可用余弦定理很方便地求出，而张角的极值点则对应于轮廓急剧变化的地方。

Namely specialized devotes to east wind brand intermediate and senior Pi Ka, SUV and MPV and extends the commodity enterprise's development, simultaneously as daily production brand LCV commodity line at Chinese enterprise's main acting.

即专业致力于东风品牌中高级皮卡、SUV和MPV及其延伸商品事业的发展，同时作为日产品牌LCV商品线在中国事业的主要担当者。

In February 2004, another leftwing activist Fang Chuang Pi passed away in Thailand after being denied re-entry into Singapore.

2004年2月，另一名左翼分子方壮壁在泰国逝世，他生前被新加坡政府禁止入境。

Dong Jinyi conveyed Hu Jintao of Chinese state chairman the kind greeting to Qian Pi's president, express to will go all lengths inside lieutenancy with meaning just boost relation of favorite two countries new height toget......

董津义转达了中国国家主席胡锦涛对钱皮总统的亲切问候，表示将在任期内竭尽全力与意方一起将。。。。。。

The optimization problem with linear inequalities can be solved by Quadratic Programming. The simulation results show that the design improves the dynamic performance and suppress torsional vibration causing by rolling perturbation. The model predictive control suppresses rolling perturbation.

仿真结果表明，采用具有约束条件的预测控制策略的控制系统对轧机传动系统的控制效果在动态性能和抑制扭振效果上明显优于传统PI控制，可以较好的抑制轧制扰动对传动系统产生的影响，对解决轧制扰动鲁棒性控制问题是一种有效的解决办法。

For a big chunk of credit-card losses; the number of filings (and thus charge-off rates) would be rising again, whether

年美国个人破产法的一个改动使得破产登记急速下降，而后引起了信用卡大规模的亏损。

Eph. 4:23 And that you be renewed in the spirit of your mind

弗四23 而在你们心思的灵里得以更新