A new Pd-oxide-Al/sub 0.3/Ga/sub 0.7/As MOS hydrogen sensor

A new and interesting Pd-oxide-Al/sub 0.3/Ga/sub 0.7/As MOS hydrogen sensor has been fabricated and studied. The steady-state and transient responses with different hydrogen concentrations has been measured at various temperatures. Based on the large Schottky barrier height and presence of oxide layer, the studied device exhibits a high hydrogen detection sensitivity and wide temperature operating regime. The studied device exhibits the low-leakage current and obvious current changes when exposed to hydrogen-contained gas. Even at room temperature, a very high hydrogen detection sensitivity of 155.9 is obtained when a 9090 ppm H/sub 2//air gas is introduced. Furthermore, when exposed to hydrogen-contained gas at 95/spl deg/C, both the forward and reverse currents are substantially increased with increased hydrogen concentration. In other words, the studied device can be used as a hydrogen sensor under the applied bidirectional bias. Under the applied voltage of 0.35 V and 9090 ppm H/sub 2//air hydrogen ambient, a fast adsorption response time about 10 s is found. The transient and steady-state characteristics of hydrogen adsorption are also investigated.     

基于模式理论光栅椭偏参数反演的数值模拟

将一种广泛用于求解系统优化问题的方法——正单纯形法，求解光栅的椭偏方程。首先，利用求解光栅的傅立叶模式理论对TE和TM波的复反射系数进行求解。然后计算出其相应的椭偏参数(△，Ψ)，并在该值的基础上加入不同偏差的随机高斯噪声，将加入噪声后的值(△m，Ψm)作为模拟测量值。最后使用优化算法进行反演。通过对几种常用面形光栅椭偏参数的数值模拟，一方面表明傅立叶模式理论计算光栅的椭偏参数不仅精度高。而且速度快；另一方面表明利用正单纯形法得到的光栅参数值很接近于正演时假设的参数值，从而从理论上证明了利用椭偏法测量光栅各种光学参数的可行性。     

Whispering-gallery-like modes in square resonators

The mode frequencies and field distributions of whispering-gallery (WG)-like modes of square resonators are obtained analytically, which agree very well with the numerical results calculated by the FDTD technique and Pade approximation method. In the analysis, a perfect electric wall for the transverse magnetic mode or perfect magnetic wall for the transverse electric mode is assumed at the diagonals of the square resonators, which not only provides the transverse mode confinement, but also requires the longitudinal mode number to be an even integer. The WG-like modes of square resonators are nondegenerate modes with high-quality factors, which make them suitable for fabricating single-mode low-threshold semiconductor microcavity lasers.     

φ90mm低铬铸球开裂失效分析

φ90mm低铬铸球在做落球试验中过早出现开裂现象。将该铸球材质进行化学成分分析、力学性能测定及金相组织观察。分析结果表明，该铸球的材料中夹杂物含量较高，其硬度值又偏高，铸球内部又存在严重缩松及其铸态组织中存在大量奥氏体转变产物，致使铸球在落球试验中过早开裂。经过工艺措施的改进，解决了铸球出现过早开裂的现象。     

不同注F剂量与CMOS运放电路辐照损伤的相关性

在不同注F剂量条件下,对P沟和N沟两种不同差分对输入CMOS运放电路的电离辐照响应进行了研究.分析比较了注F和未注F运放电路电离辐照响应之间的差异.结果表明,在栅场介质注入适量的F,可有效抑制辐照感生的氧化物电荷尤其是界面态的增长,从而提高CMOS运放电路的抗辐照特性.     

数值试井在白6-2井测试资料分析评价中的应用

数值试井是在近来发展的一项新的试井解释技术，具有处理非均质，复杂边界油气藏问题的优点，弥补了常规解析试井技术的不足。运用数值试井解释技术，结合动、静态资料，通过对白6-1断块白6-2井测试资料的综合分析评价，确定了储层渗流参数，落实了该气藏的边界情况，为该断块下一步开发提供可靠依据。     

魏氏组织对20#碳钢H2S应力腐蚀开裂性能的影响

文章对H₂S-CO₂-H₂O腐蚀环境下发生H₂S应力腐蚀的20^＃碳钢弯管（无缝钢管）进行了成分、组织、拉伸、硬度和应力腐蚀开裂等性能的试验研究，并与同材质、同时投产、腐蚀环境基本相似而未发生应力腐蚀开裂的在役弯管及未使用的新弯管作对比，结果表明魏氏组织是引起20^＃钢发生应力腐蚀开裂的主要原因；正火能消除魏氏组织，降低钢的应力腐蚀开裂敏感性。     

一类Feistel密码的线性分析

该文提出一种新的求取分组密码线性偏差上界的方法，特别适用于密钥线性作用的Feistel密码．该分析方法的思路是，首先对密码体制线性偏差进行严格的数学描述，分别给出密码线性偏差与轮函数F及S盒的线性偏差的数学关系；然后通过求取线性方程组最小重量解，确定密码线性偏差的上界．     

用CMOS工艺实现VSR光电集成接收机的途径

介绍了10Gbit／s速率的甚短距离光传输系统VSR(Very Short Reach)中的接收机。分析了几种有希望用于VSR系统的CMOS工艺兼容的光电探测器。提出用CMOS电路实现VSR光电集成(OEIC)接收机的可能性和实现方法。