网格计算及其应用

网络计算给互联网带来了新的活力，它是一种新型的分布计算技术，致力于解决复杂度很高的新应用问题，文中简述了网格计算的定义、体系结构、关键问题、当前几个有代表性的网格系统以及网格应用实例，并分析了风格计算发展趋势。     

First Harmonic (2f) Characterisation of Resonant Frequency and Q-Factor of Micromechanical Transducers

In this paper, the response to the first harmonic component (2f) of the electrostatic force in single terminal driven electrostatic comb-drive and parallel-plate drive was used as a signal to extract device parameters, namely, the Q-factor and resonant frequency instead of the fundamental (1f) resonance response. It is shown that the difficulty in motional measurement due to electrical cross-talk (parasitics) using 1f measurement can be overcome with a higher signal-to-noise ratio of the 2f signal. Both atmospheric (low-Q) and reduced pressure environment were investigated using off-chip electronics and lock-in amplifier. The measurements were done on the electrostatic comb-drive and capacitive parallel plate sensing plates that form the two core modules of a yaw rate sensor (dual-axis resonator). The effects of AC and DC bias voltages on the measured response have been investigated. Experimental amplitude and phase response data have been analysed using the Lorentzian curve-fit, Resonance Curve Area (RCA) method, the half-power bandwidth method (3 dB) and the Nyquist plot for data fitting and determination of the Q-factor and resonance frequency.     

Analysis and Optimization of Noise in Bipolar RF Harmonic Mixers

A noise analysis of bipolar harmonic mixers (BHM) used for direct-conversion receivers is presented in this paper. Analytical and simulated results for the transfer function of the mixer are presented. Simple analytical expressions describing noise contribution from all sources are derived. Estimation of flicker noise quite agrees with harmonic-balance simulation results. Based on the derived expressions, total time average noise power spectral density (PSD) at the output is compared with simulation results. For the recommended regions of operation, error is less than 20%. The overall BHM noise figure (NF) is calculated and optimized based on a simple extracted formula. Errors introduced by analysis remain within a 1.5-dB margin with respect to simulation results. The validity of analysis for high frequencies is justified. The effect of flicker noise coefficient on the overall mixer NF is compared for different available processes.     

SF6气体绝缘电容式电压互感器研制

本文介绍西容公司新研制的一种完全无油化的SF6气体绝缘电容式电压互感器,提出了关键技术问题解决方案和产品绝缘结构的设计思路.并介绍了研制成功的110kV和220kV系列产品的结构、技术参数、性能指标、试验考核情况和产品特点.     

浮栅技术及其应用

介绍了浮栅技术的基本原理及应用情况。井对2种应用了浮栅技术的典型器件-浮栅MOS晶体管和神MOS晶体管做了详细介绍，分析了他们的基本结构和工作原理，以及建立浮栅MOS晶体管的等效模型，并说明了他们的应用情况及存在的不足。     

网格技术在广播电视中的应用

网格是继Internet和Web技术之后的第三个信息技术浪潮。简述了网格的定义、特点和基本体系结构 ,并且分析了网格技术在广播电视中的应用     

有限转角无刷力矩电动机位置伺服系统的电流控制

提出了有限转角无刷力矩电动机 (LABLTM)位置伺服系统电流控制策略 ,给出了实施方法 ,进行了开关管频率特性的分析。该方法可实现在不同误差时自动调节电动机电流 ,进而控制输出转矩 ,并具有稳态精度高、动态响应快等特点。     

电阻式电压传感器结构设计及误差特性研究

从路的角度分析了电阻式电压传感器的误差特性 ,从场的角度比较了几种结构方案的幅值误差、相角误差及最大场强 ,优化出最佳方案 ,并分析了该方案幅值误差的频率特性     

氧化铝丝的研制

氧化铅丝生产过程中最关键的工艺是连续阳极氧化。氧化膜击穿电压决定于氧化膜厚度。控制膜厚度的三要素为:电解液(成份、浓度及温度),槽电压和铝丝走速。     

PWM开关变换器统一建模法与谐波分析法的应用

介绍了PWM开关功率变换器电路的统一建模方法，并将谐波分析方法应用于电路分析中，理论和实例表明，这种方法容易得到电路变量的基波解和各次谐波解，以及电路的传递函数，具有容易理解和准确度较高的优点。