调波

This article introduces the design feature and performance test of DK9 motor coach with two-phase-double-circuits in Beijin Underground.

本文介绍了北京地铁 DK9型电动客车采用两重两相斩波调压的设计特点和性能试验。

Running results has confirmed that the choppercontrolled motor coach made in China can practically put into service.

运行结果表明我国斩波调压电动客车已进入实用阶段。

Following that, we implement the algorithms of FOC, space vector pulse-width modulation, and speed control using the digital signal processor. Regarding to the influence of controller parameters on dynamic response of the motor speed, this thesis proposes the speed control of PMSM using self-tuning fuzzy technique. By the self-tuning technique, the on-line fuzzy logic controller output can give better speed response under the load disturbances or variable speed commands.

本文首先使用数位讯号处理器完成磁场导向控制、空间向量脉波宽度调变及速度控制之策略，针对控制器参数对系统动态响应之影响，提出采用自调式模糊控制器於速度控制回路，藉由自调式机制，线上调整模糊控制器之参数，使PMSM在变动负载及速度命令下有较佳之动态响应，达到提升系统响应及强健性之目的。

In this paper, the analytical expressions of seismic input for homogeneous elastic half-space are first derived in oblique incidence of plane SV-wave, and then a finite element model for a real hydropower cavern group composed of main powerhouse- transformer chamber- tailrace surge tank cavern is created. Characteristics of seismic responses such as displacement, acceleration and stress are studied in detail at different incidence angles and some results are compared with those given by the literature.

本文首先推导了平面SV波斜入射下均质弹性半无限空间的地震动输入表达式，然后建立了某水电站主厂房室-主变室-尾水调压室等构成的地下洞室群有限元模型，详细研究了不同入射角度下各洞室的位移、加速度、动应力等地震反应特点，并与文献进行了对比。

Chopin Polonaise in A Flat Major Op.

波罗奈斯舞曲在A降半音大调

It is pointed out, while expounding the principle of chopper speed variation, that the value of peak current can affect the service life of components and so it is necessary to control.

文章阐述了斩波调速原理，指出峰值电流的大小会影响元器件的寿命，所以有必要对瞬时电流的大小进行控制。

During high load, in active clamp circuit, output diode will be converted into MOSFET、a current transformer and PWM fan controller are used to reduce total power consumptions. To achieve EPA regulation.

在输出负载为重载(100%)时，将主动箝位线的将输出端的整二极体改为功晶体、使用电变压器和脉波调变输出的风扇控制方式减少总功的耗，以达到加州能源法节能的规范。

The main contents is: analyzing some detection method to moving target nowadays; particular studying the principle of detection moving target in SAR; analyzing SAR imaging theory and the echo model of moving target; discussing conventional SAR imaging , the movements of target cause the changes of doppler mass center and regulable frequency, and the changes cause effect the imaging result; introducing the estimation method of doppler parameter; analyzing theory of DPCA, derivating the formula needed, and validating it's validity and practicability through simulation; advancing the improved DPCA algorithm that combine the advantage of DPCA and ATI, and validating it through computer simulation; using the revision algorithm to range ambulate based on keystone transformation, and validating it through computer simulation; discussing the compensation art of SAR imaging.

主要内容有：分析了现有的一些动目标的检测方法；详细研究了SAR动目标检测的原理；分析了SAR成像理论和运动目标的回波模型；探讨常规SAR成像时，目标运动引起的多普勒质心和调频率变化，以及这些变化对成像结果的影响；介绍了多普勒参数的估计方法；分析了DPCA原理，推导所需要的基本公式，并仿真验证其有效性和实用性；提出了结合DPCA和ATI优点的改进DPCA算法，并仿真验证；探讨了SAR成像中的运动补偿技术。通过对仿真结果的分析，本文提出的方法具有一定的指导意义和参考价值。

The system has not only similar function to the traditional ACDCAC variable frequency system, but also compact structure, small volume and light weight. It can shape the input current into sinusoidal wave, with no harmonic pollution to grid.

其功能类似于传统的变频调速系统，而其结构紧凑，体积小，重量轻，并且输入电流为正弦波，对电网无谐波污染。

Gaussian function through derivative edge detection in real terms is Steerable Wavelet image edge detection.

详细说明：通过高斯函数导数检测图像边缘，实质是方向可调小波变换检测图像边缘。

Since historical times,England ,where the early inhabitants were Celts, has been conquered three times .

从有历史以来，英国，在此地早期居住的是凯尔特人，已经被征服了三次。

Bluetooth OBEX File Transfer Enables the sending and receiving of files on your phone via Bluetooth.

蓝牙OBEX文件移动允许经过蓝牙传送和接受文件。。。。