Unified analytical expressions for calculating resonantfrequencies, transimpedances, and equivalent input noise currentdensities of tuned receiver front ends

Unified analytical expressions have been derived for calculating the resonant frequencies, transimpedance and equivalent input noise current densities of the four most widely used tuned optical receiver front ends built with FETs and p-i-n diodes. A more accurate FET model has been used to improve the accuracy of the analysis. The Miller capacitance has been taken into account, and its impact on the performances of the tuned front ends has been demonstrated. The accuracy of the expressions has been verified by Touchstone simulations. The agreement between the calculated and simulated performances of the front ends is very good. The expressions can be used to investigate the performances of different tuned front ends in a very simple way and provide a good starting point for further computer optimizations of the front ends     

用瞬态频率波动法诊断齿轮故障

利用瞬态频率波动法实现频率调制信号的解调，提取齿轮的局部裂纹信息，并通过黄河ＴＮ２５２型汽车变速器疲劳试验的信号分析来验证。     

Preliminary Study on Aluminium-based Nanophase Composites Al_(88)Ni_(10)Y_2 and Al_(88)Ni_8Y_4

A new kind of aluminium-based alloy part amorphous/part crystalline, can be produced directlyby rapid quenching of the liquid. These materials have a novel structure of nanometer-sizedcrystals in an amorphous matrix and quite remarkable mechanical properties. The materialscan be considered to be nanophase composites. In this work Al88Ni10Y2 and Al88Ni8Y4 (atpct) nanophase composites consisting of a nanoscale dispersion of fcc-Al crystallites uniformlydispersed in an amorphous matrix, have been produced by melt-spinning. They have much highermicrohardness HV than fully amorphous alloys with the same composition. while retaining goodbending ductility The volume fraction, crystallite size and distribution of the fcc-Al phase havebeen estimated by DSC. X-ray diffraction and TEM. lt is found that the microstructure andproperties of the nanophase composites are very sensitive to the composition and the quenchingconditions. lncreasing the Y contedt and decreasing the Ni content at a given Al content givesmuch smaller dispersed nanophase aluminium crystallites. The volume fraction and crystallitesize of the fcc-Al phase increase with a decrease of wheel speed (quenching rate). The effectsof Y and Ni contents on the ease of formaticn of the nanophase composites are discussed. Theorigins of the novel mechanical properties are also considered.     

I．O．T．旧梦成真

该文较详细地介绍了Ｉ．Ｏ．Ｔ管的发展历程，其特点及工作方式。     

Silicon doped carbon/Cu joints based on amorphous alloy brazing for first wall application

Amorphous ribbon-type filler-metals represent a promising selection for joining heterogeneous materials together. In this work, rapidly solidified ribbon-type Ti based amorphous filler with a melting temperature of 850 °C and a thickness up to 20 μm is used to join silicon doped carbon to pure copper. SEM examinations demonstrate that a high quality brazed joints could be acquired. The brazed seam has a uniform structure and pore free along its entire length. TiC and ZrC are formed near the interface of carbon and filler-metal when the brazing holds enough time. Using very thin Mo and Cu foil (0.2 mm in thickness) as multiple interlayer are very effective to mitigate the thermal stress occurred in the interface between carbon and copper. The shear strength of this carbon-multiple interlayer-copper joint is more than 20 MPa, and the rupture is mainly occurred on the carbon side.     

Monolithic Catalysts with Low Noble-Metal Content for Exhaust Purification of Small Gasoline Engines

A series of low noble-metal coment monolithic catalysts for exhaust purification of small gasoline engines was investigated, and it was found that the Pt/Rh-OSM/Al2O3 （where OSM was oxygen storage material） catalyst with Ce0.5Zr0.5-MnOx（3%MnOx） OSM held low light-off temperature for CO, HC, and NO; quite wide three-way window, and outstanding thermal stability. The catalyst could efficiently comrol exhaust emission of small gasoline engines.     

柔性轧制Q390C和Q420C钢板生产实践

目前市场对中厚板的订单具有个性化和多样化的特点，而对于不同强度级别的钢板，化学成分设计往往是不同的，这样会增加不同钢坯冶炼之间衔接的时间及化学成分控制的难度，导致冶炼成本增加，工序复杂化。结合市场需求与生产实际，采用同一Q390低合金高强度钢板坯，通过不同的控轧控冷工艺，对Q390C和Q420C两种强度级别热轧钢板进行了试制。结果表明，通过控轧控冷技术，可以充分发挥细晶强化作用，采用同一Q390低合金高强度钢板坯实现了Q390C和Q420C两个强度级别热轧钢板的柔性生产。试制生产的两种钢板，强塑性及0 ℃冲击功均满足标准要求，Q420C钢板屈服强度达441 MPa以上，抗拉强度达579 MPa以上。采用柔性轧制技术，降低了Q420C高强钢板的生产成本。     

A method for designing high-power offset Cassegrain antennas

Starting from the geometrical parameters of the feed and the desired gain of the Cassegrain antenna, a method to determine the design starting parameters for a high-power offset Cassegrain antennas is discussed. Then, by numerically solving the equations governing the antenna geometry, a set of design curves are obtained, with which the structure of the antenna can be determined by trading off the electrical and geometrical system requirements. The method presented can be applied to both high or low gain feeds for constructing a high power microwave electromagnetic environment, where complex electronic systems can be tested. For linearly polarized feeds with high gain, the structure parameters of antenna with zero cross polarization can be obtained, which is equal to the design results of Brown and Prata (see IEEE Trans. Antennas Propagat., vol.42, no.8, p.1145-53, 1994)     

一种彩色C型显示及数据处理终端

本文介绍了一种利用数字信号处理器ＴＭＳ３２０Ｃ２５用作雷达数据实时处理，利用图形处理器ＴＭＳ３４０１０用作雷达视频图象处理，完成雷达视频图象彩色显示的雷达终端。     

异丁醛氧化制丙酮热导气相色谱分析

本工作用２米４０１有机担体填充柱，在带四臂热导检测器的国产１０３型气相色谱仪上，仅８分钟将原料异丁醛、产物丙酮及水进行良好分离，并采用内标法定量，其最大平均偏差在±２％以内。方法简单、快速、准确