S频段大功率振荡用砷化镓场效应晶体管的微波性能

对WC76型S频段大功率振荡用砷化镓场效应晶体管的微波性能作了介绍。文中给出了测试振荡器的设计。测试结果表明,WC76型振荡管在s频段的微波性能良好,振荡频率在3GHz左右时,输出功率可达3.5w,直流—射频转换效率可达44％,而且在2～4GHz的整个S频段均能满意地工作。     

最优化分析使网络电路输出功率最大

用最速上升法分析具有多负载的有源线性网络电路,使其输出功率最大,它可以为电子器件端口的合理布置提供最优数据。     

Equilibrium solubility of CO2 in rubbery EVA over a wide pressure range: effects of carbonyl group content and crystallinity

The equilibrium CO₂ sorption isotherms and isobars for rubbery EVA containing various amounts of vinyl acetate (VA) over a wide pressure range 10-340 atm and 25-52 °C were investigated. The normalized CO₂ sorption concentration (in cm³ (STP) CO₂/mole VA) isotherms of these polymers as a function of pressure consisted of two distinct regions turning at near P_c. The normalized sorption isotherms in these two distinct regions could be fairly described by two respective power laws: C=K_aP^n_a for above P_c and C=k_bP^n_b for below P_c. The normalized CO₂ sorption isotherms were found to be about the same for four EVA samples having different VA contents for below P_c, suggesting that the sorption process at below P_c may be mainly driven by the presence of carbonyl groups. At above P_c, the degree of crystallinity of the polymer appeared to be a major factor to affect the sorption process, with the higher the degree of crystallinity, the lower the normalized CO₂ sorption concentration in the polymer. The sorption isobars of the polymer as a function of temperature were governed by the interplay of density, viscosity, and diffusivity of CO₂ depending on the pressure studied.     

权力及正确权力观的标志

权力是统治阶级的权力,是统治阶级统治力量和意志的体现,是为统治阶级的利益服务的。在社会主义社会,权力是人民的权力。保证权力的人民性必须有相应的权力运行机制,在根本上则取决于领导干部树立正确的权利观,坚持为民执政、为民勤政、为民廉政。     

红外加热节能技术的现状与发展前景

本文综述了国内外节能的现状与发展趋势,论述了远红外电加热领域的发展前景,强调了加强基础理论研究的重要性,介绍了我国红外加热应用的领域和国外新开发的红外产品。     

Silicon power MOSFET at low temperatures: A two-dimensional computer simulation study

Understanding how the structure of the unit-cell affects the cryogenic performance of a Si power Metal Oxide Semiconductor Field Effect Transistor (MOSFET) is an important step toward optimizing of the device for cryogenic operations. In this paper, numerical simulations of the Si power Double Diffused MOSFET’ (DMOS) are performed at room temperature and cryogenic temperatures. Physically based models for temperature dependent silicon properties are employed in the simulations. The performances of power DMOS’ with various unit-cell structures are compared at both room temperature and low temperatures. The effect of the cell structure on the on-resistance and breakdown voltage of the device are analyzed. The simulation results suggest that the device optimized for room temperature operation can be further optimized at cryogenic temperatures.     

多功能半导体激光医疗仪电源的研制

根据“多功能半导体激光医疗仪”整机的要求,采用同一电源对667nm和808nm半导体激光器实施供电。为避免电源在开、关机时对半导体激光管产生浪涌冲击,电源在设计中采用了适当的逻辑功能。并可保证对667nm激光器供电时,即使打开808nm激光器供电开关,也不对808nm半导体激光器供电,反之亦然。电源设有手动、计算机两种控制方法,及恒定功率、电流两种工作方式。     

300脚MSA 10 Gbit/s Transponder模块

分析了开发10Gbit/sTransponder模块的必然性，介绍了10Gbit/sTransponder模块的原理、特点和参数指标。并且用开发出的两只40km300脚10Gbit/sTransponder模块成功地进行了43km的无误码传输试验和测试。     

高性能IGBT模块的设计考虑

本文对ＩＧＢＴ模块中功率芯片（ＩＧＢＴ和续流二极管）的优化设计进行了讨论。通过优化几个重要的工艺参数并改进器件的结构，ＩＧＢＴ不仅有足够的短路容量，而且正向压降与电流下降时间之间可实现最佳折衷。另外，续流二极管的反向恢复特性也有明显改善。通过采用衬底控制技术，ＩＧＢＴ模块的输出特性不受温度的影响，输出电流更稳，输出阻抗更高。本文详细介绍了整个设计考虑。     

模拟电路的模块级故障诊断

本文以多端口元件或子网络为基本单元，提出了一种模块级故障诊断方案，这种方案的故障模型更符合电路的实际情况，因而具有更广泛的实际意义，文中首先推导了模块故障诊断议程，并对模块故障可测性问题进行了一般性讨论。然后，给出了模块故障可测的几个拓扑条件，并通过定义广义独立通路使这些拓扑条件适用于一般的非互易网络。