一种基于FPGA的可变速率帧结构设计与实现

在简述V.35接口的基础上针对V.35接口速率可变的应用需求提出了一种速率可变的帧结构,该帧结构可支持N×64kb/s(3≤N≤32)速率,从而在V.35接口上实现了多种速率的低速业务传输.     

Linear friction welding of Ti6Al4V: experiments and modelling

Linear friction welding of the Ti6Al4V alloy is studied. A new definition of the energy input rate is proposed, based on an integration over time of the in-plane force and velocity; a strong correlation with the upset rate is then found. The effective friction coefficient is estimated to be 0·5±0·1 for varying frequencies and amplitudes, with only a weak dependence on the processing conditions displayed. A model is proposed that accounts for both the conditioning and equilibrium stages of the process, which is shown to be in good agreement with the experimental data. The model is used to study the mechanism by which the flash is formed. A criterion is proposed by which the rippled nature of its morphology can be predicted.     

烧结工艺对液相合成（SrPb）TiO3基陶瓷热敏特性影响的研究

本文在液相合成（ＳｒＰｂ）ＴｉＯ３粉的基础上，研究了升温速率、保温时间、烧结温度及降温方式对（ＳｒＰｂ）ＴｉＯ３基陶瓷的Ｖ型ＰＴＣ热敏特性的影响。实验表明：升温速率对其热敏特性影响不大，保温时间和烧结温度的作用是一致的，具有一最佳范围。而降浊方式对材料的热敏特性影响较大。综合各因素的影响，本配方中，样品的烧结制度定为：以２００℃／ｈ的速率升温，在１２５０℃保温１ｈ，炉冷至９５０℃，保温０．５ｈ，再     

LD钢超塑性压缩变形参数与金相组织

通过对ＬＤ（７Ｃｒ７Ｍｏ３Ｖ２Ｓｉ）模具钢起塑性压缩变形后的金相组织观察研究，分析了变形参数、原始组织对变形后金相组织的影响。     

Breakdown characteristics of oil and paper insulation for a very fast transient voltage

This paper describes the dielectric breakdown characteristics of oil and oil‐impregnated paper for very fast transient (VFT) voltages. Blumlein circuits generate VFT voltages of 60 and 300 ns in a pulse width that simulates disconnecting switching surges in gas‐insulated switch gears. We measured the breakdown voltages of needle‐to‐plane, plane‐to‐plane oil gaps and several pieces of paper between plane electrodes for VFT and lightning impulse voltages. The measured data were formulated in V‐t characteristics and Weibull probability distributions. The inclination n of V‐t characteristics of insulating paper is 150, which is less than n = 13.7 of the plane‐to‐plane oil gap in the VFT time range. The shape parameters of Weibull distribution obtained in this study show that the scattering of breakdown voltages of paper is much less than that of oil. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(4): 16–24, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10043     

HSDPA部署策略及覆盖、容量规划

本文介绍了HSDPA的发展背景,针对HSDPA的主要技术特点,依据市场发展规划、用户需求等方面对HSDPA部署进行探讨,并对HSDPA的覆盖与容量方面进行规划分析.     

David V. Smith (1943-2006).

Presents an obituary for David V. Smith, who succumbed to a brain tumor on September 30, 2006 at the age of 63. He was Simon R. Bruesch Professor and chair of the Department of Anatomy and Neurobiology and the director of the Neuroscience Institute at the University of Tennessee Health Science Center (UTHSC). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exchange and oxidation of CO on O-predosed Rh---Al2O3 and Rh---CeO2 catalysts

Exchange and oxidation of C¹⁶O were investigated at 450°C on ¹⁸O-predosed Rh and Pt catalysts supported on A1₂O₃, CeO₂ and CeO₂-Al₂O₃. In all cases, a rapid exchange of C¹⁶O with the surface can be observed. CO oxidation leads to C¹⁶O₂, C¹⁶O¹⁸O and C¹⁸O₂. Significant formation of C¹⁶O₂ is due to the relatively high ¹⁶O coverage in reaction resulting from the C¹⁶O exchange and from an exchange between O surface species and ¹⁶O internal atoms. Hydrogen is also formed via a water-gas shift reaction (CO + surface OH) in higher proportion on CeO₂-containing catalysts than on A1₂O₃. Chlorine inhibits all the reactions (exchange, oxidation and WGS) and particularly the internal exchange.     

高速钢W6Mo5Cr4V2的脱磷试验

在３０ｋｇ感应炉上用ＣａＯ－Ｎａ２ＣＯ３－ＣａＦ２－ＦｅｘＯ（ＭｏＯ３）渣、ＭｏＣｌ６粉剂和Ａｌ－Ｃａ合金作脱磷剂对高速钢Ｗ６Ｍｏ５Ｃｒ４Ｖ２进行脱磷试验。结果表明，ＣａＯ－Ｎａ２ＣＯ３－ＣａＦ２－ＦｅｘＯ渣的脱磷效果最好，一般脱磷率可达２６％￣５６％。     

p,V, T and derived thermodynamic data for toluene,trichloromethane, dichloromethane,acetonitrile, aniline,and n-dodecane

Experimentally determined p,V,T data are reported for toluene, trichloromethane, dichloromethane, acetonitrile, aniline, and n-dodecane at 278, 288, 298, 313, and 323 K, except for dichloromethane, for which the highest temperature was 298 K. At each temperature, measurements were done at pressures up to about 280 MPa or (for aniline and n-dodecane) at a lower pressure slightly below the freezing pressure at the temperature of measurement. Values of the isobaric expansivity isothermal compressibility and (for toluene, trichloromethane, dichloromethane, and acetonitrile) internal pressure, derived from the p,V,T data, are presented.