激光修调对CrSi薄膜电阻稳定性的影响

该文分析了激光修调对CrSi薄膜电阻稳定性的影响,获得了对CrSi薄膜电阻进行激光修调的优化方法.实验结果表明,150 ℃储存48 h,可完全消除激光修调带来的影响,使CrSi薄膜电阻温度系数降到了20×10-6/℃,提高了CrSi薄膜电阻网络的稳定性,从而为研制高性能模拟集成电路打下坚实的基础.     

具有阵列分布光束输出的TEA CO2激光器研究

通过对封离型外腔TEA CO2激光器谐振腔的腔元件参数的特殊选择,即选用两表面有夹角的未镀膜的Ge镜作为谐振腔的输出镜,得到阵列分布的激光束.绕腔轴旋转输出镜,在不同的角度可以得到不同的阵列输出光束.近场区域光斑尺寸内点阵数达7×16,光斑大小为26mm×17 mm,利用等厚干涉原理分析了这种光束的产生原因.     

Simulation and design methodology for a 50-Gb/s multiplexer/demultiplexer package

A 50 Gb/s package for SiGe BiCMOS 4:1 multiplexer and 1:4 demultiplexer targeting SONET OC-768 serial communication systems is introduced in this work. The package was designed to facilitate bit-error-rate tests and constructed with high-speed coaxial connectors, transmission lines on ceramic substrate, ribbon bonds for chip-to-package interconnects, and a metal composite housing. Numerical simulations were conducted to guide the package design, and both small signal measurements and operational tests were performed thereafter to verify the design and modeling concepts. To keep the model structure under the existing computing capability, the simulation was segmented into three sections - coaxial connector to transmission line, transmission line alone, and transmission line to ribbon bond, and then the results were assembled to predict the performance of the entire package. The package was operated up to 50 Gb/s with low degradation to input digital waveforms and free of error.     

MC-CDMA系统存在频偏时的性能分析

多载波码分多址(MC-CDMA)是把正交频分复用(OFDM)和码分多址(CDMA) 结合起来的新一代移动通信系统.详细构建了一个MC-CDMA 系统的数学模型,并给出了载频偏移和多径信道存在时的矩阵-向量表示模型.在此系统模型的基础上,分析了频偏对MC-CDMA系统多用户检测器性能的影响.MATLAB仿真显示了MC-CDMA系统对频偏极为敏感,当经历多径Rayleigh信道时,系统只能忍受较小的频偏.     

多芯电缆屏蔽效能测试方法研究

首先介绍了屏蔽效能的定义,然后根据多芯电缆和同轴电缆的区别与联系,提出了适用于测量多芯屏蔽电缆效能的注入线测试方法,并且比较了测试结果和仿真结果,为测试人员合理选择有效的测试方法提供了依据。     

FDTD方法分析金属机箱的屏蔽特性

文中采用时域有限差分法对带孔缝机箱的屏蔽特性进行了仿真分析。比较了入射场极化方式不同的情况下机箱的屏蔽特征,得出的分析结论可用于指导机箱的电磁屏蔽设计和防护。     

A Model With Temperature-Dependent Exponent for Hot-Carrier Injection in High-Voltage nMOSFETs Involving Hot-Hole Injection and Dispersion

An improved hot-hole-involved interface-state generation model is proposed for hot-carrier injection (HCI) degradation in high-voltage (HV) nMOSFETs. This model is based on experiments over a wide range of temperatures, voltage conditions, simulation results, and the underlying physical mechanisms. The model provides a thorough picture of an HCI system in HV nMOSFETs, with hot-hole injection related to an additional maximum electric-field region. The hot-hole injection in HCI is assumed to introduce deeper localized hydrogen states in gate-oxide films than that in negative-bias temperature instabilities. This result facilitates the dispersive transport of hydrogen. Therefore, HCI degradation in HV transistors is explained within the framework of disorder-controlled hydrogen kinetics. The power-law model can successfully predict temperature dependences for HCI degradation.     

利多卡因防治大鼠深二度烧伤创面早期加深的作用

目的探讨利多卡因防治深二度烧伤创面早期加深的作用。方法wistar大鼠背部深二度烧伤,治疗组局部应用利多卡因凝胶,对照组涂抹安慰剂,检测烧伤后创面组织中Na-K-ATP酶、髓过氧化物酶(MPO)活性和琥珀酸脱氢酶(SDH)、丙二醛(MDA)的含量,HE染色及增殖细胞核抗原(PCNA)免疫组化染色显示创面组织坏死程度。结果对照组和治疗组SDH和Na-K-ATP酶活性在伤后24h均达到最低,之后逐渐升高,但远低于正常水平。伤后24h治疗组SDH、Na-K-ATP活性高于对照组(P<0.05);对照组MPO酶活性在伤后24h达最高,治疗组在伤后48h达最高,之后两组都降低,但仍高于正常水平,对照组MPO活性最高值高于治疗组(P<0.05);对照组和治疗组伤后MDA含量一直升高,伤后72h,对照组高于治疗组(P<0.05)。HE及PCNA染色显示治疗组早期创面进行性损伤明显延缓且较轻,创面组织增殖活力好于对照组。结论深二度烧伤创面早期局部应用利多卡因可减轻创面加深,其机制可能与抑制白细胞浸润、减轻氧化损伤、改善组织活力等因素有关。     

基于Web的控制电机多媒体教学课件的开发

基于Web的控制电机教学课件是多媒体CAI课件与Web技术的结合。它利用网络丰富的表现手法和超级链接将抽象的理论形象化。本文介绍了基于Web的控制电机多媒体CAI课件开发的过程和网络课件在控制电机辅助教学中的优势。     

同步仿生机械臂设计

本设计利用安装在人手臂部的加速度传感器采集运动信号,单片机智能运算后发出控制指令,实现机械臂与人臂的同步运动。系统将在采集传感器的输出模拟量经过单片机的处理产生PWM波,使用PWM波驱动舵机实现准确定位,使机械臂实现三自由度的运动。而且还可通过编程和仿生来完成各种预期的作业任务,在构造和性能上兼有人和机器各自的优点,体现了人的智能和适应性。