Schwingfestigkeit von Schraube‐Mutter‐Verbindungen

High cycle fatigue of bolted connections Extensive tests regarding the influences on the fatigue of bolt‐nut‐connections of preloading with torsion, of preloading with yielding, of loading with superimposed bending and of the tested lot are processed. These influences are not yet known according to VDI 2230. New testing devices were designed for these tests, which allow a far less expensive operation and may easily be used for bolts of diameters up to M100 and testing frequencies up to 1000 Hz. The validity of fatigue resistance according to VDI 2230 is specified with respect to the test results. The determined influence of the tested lots is unexpectedly high. The manufacturing process of bolts should be improved to minimize this influence.     

OFDM-MIMO系统及其频率同步分析

多媒体业务对无线通信的带宽与品质提出了更高的要求，OFDM和MIMO由于满足了这一需求被越来越多的无线通信标准采用所为底层的调制和传输技术。频率同步问题是OFDM—MIMO物理层设计中正确解调的前提和基础，本文介绍了OFDM—MIMO的原理、特点和频率同步问题的研究现状。     

Ф16mm、Ф18mm钼棒的研制

采用等静压制法，压制钼圆棒坯，经中频高温烧结，制得尺寸适合、用户满意的钼电极棒。     

IC—V100电台锁相环频率合成器

本文从频率合成器的结构、功能入手,详细阐述了频率编程的原理及方法。     

"JDS-音频化渣微机综合检测系统"的应用与效果

简要介绍“JDS-音频化渣微机综合检测系统”的工作原理和应用效果，证明使用该装置是提高炼钢操作水平的一条较好途径。     

Frequency response function of magnetic bearings using high-temperature superconductor

A high-temperature superconductor YBa₂Cu₃O_7-x with strong pinning force has allowed stable magnetic suspension with no control to be developed. Two types of superconducting magnetic bearings (SMB) using YBCO and permanent magnet were assembled. The two types are radial and axial. The dynamic stiffness of each SMB as it was cooled down under a magnetic field by liquid nitrogen was measured both radially and axially. As a result, it was found that the spring constants of these SMBs were almost as large as a practically desirable value; however, their damping coefficients were lower than the practical level. These findings are useful as one of the data bases for development of an optimum SMB design to support the weight of rotors in an axial direction.     

Series resonant ZCS‐PFM DC‐DC power converter with high‐frequency high‐voltage transformer link for high‐power magnetron drive

This paper presents a single lossless inductive snubber‐assisted ZCS‐PFM series resonant DC‐DC power converter with a high‐frequency high‐voltage transformer link for industrial‐use high‐power magnetron drive. The current flowing through the active power switches rises gradually at a turned‐on transient state with the aid of a single lossless snubber inductor, and ZCS turn‐on commutation based on overlapping current can be achieved via the wide range pulse frequency modulation control scheme. The high‐frequency high‐voltage transformer primary side resonant current always becomes continuous operation mode, by electromagnetic loose coupling design of the high‐frequency high‐voltage transformer and the magnetizing inductance of the high‐frequency high‐voltage transformer. As a result, this high‐voltage power converter circuit for the magnetron can achieve a complete zero current soft switching under the condition of broad width gate voltage signals. Furthermore, this high‐voltage DC‐DC power converter circuit can regulate the output power from zero to full over audible frequency range via the two resonant frequency circuit design. Its operating performances are evaluated and discussed on the basis of the power loss analysis simulation and the experimental results from a practical point of view. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 79–87, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20126     

LD泵浦的声光调Q腔内倍频激光器

研制成用ＬＤ泵浦的声光调Ｑ的Ｎｄ：ＹＶＯ４－ＫＴＰ腔内倍频激光器，得到了ＴＥＭ００模、频率高达１００ｋＨｚ的稳定的５３２ｕｍ绿激光脉冲系列输出，阈值泵浦功率为２７ｍＷ；在连续５７０ｍＷ的泵浦功率下，绿激光脉冲的峰值功率达１１００Ｗ，脉宽为４．６ｕｓ；输出功率稳定，在±５℃的工作温度变化下，输出功率变化小于±２％。此种器件可望得到广泛的应用。     

宽频带函数波形产生器的研制

本文介绍以ＭＡＸ０３８为基础而研制的宽频带函数波形产生器，它可以产生２￣２×＾７Ｈｚ频率范围的正弦波、三角波、锯齿波和矩形波以及与它们同步的ＴＴＬ脉冲信号。