Theoretical study on gain and tuning characteristics of infrared-microwave pumped NH3 FIR laser

Based on the semi-classical density matrix equation theory, the gain and tuning characteristics of infrared-microwave pumped NH₃ FIR laser were studied. It was shown that quasi-continuously tuning could be obtained by the tuning of microwave frequency and the efficiency of the laser could be enhanced by electric dipole transition enhancement effect, but compromise should be made between FIR laser output and frequency tuning range.     

声光器件的换能器带宽—换能器增透膜系的选择

通过计算机编程运算ＴＬ－Ｆ曲线来讨论换能器的带宽，实现了声增透膜系的选择。     

二元光栅照明研究

采用部分相干成象理论对二元光机照明进行了较为详细的研究。分析了二元光栅照明对分辨力，焦，照明能量和照明均匀性的影响，并通过实验研究验证了二元光栅对分辨力和焦深有较大程度的提高，同时能量损失不大。     

用边界元法提取VLSI版图电阻

介绍了ＶＬＳＩ版图验证中电阻提取的基本原理和主要方法，给出了一种新颖的基于边界元法的电阻提取算法。该算法采用变节点单元，较好地解决了实际问题中经常出现的角点问题。通过应用该算法对几个实例进行提取，证明使用本文的算法不仅在精度上而且在占用ＣＰＵ时间上都取得了令人满意的效果     

The preparation and magnetic properties of Fe-Ag granular solid using a sol-gel method

The Fe-Ag granular metal solid samples with 10% and 30% weight iron have been successfully fabricated using a sol-gel method, which are characterized by X-ray diffraction and transmission electron micrography. The average diameters of iron particles are from about a few nanometres to a few tens of nanometres controlled by the reducing temperature. The evolution of magnetic properties and microstructure during heat treating are described in detail and explained by using the superparamagnetism, single domain and multi domain theories. The magnetic anisotropy of the Fe-Ag granular solid is studied by using the law of approach to saturation. It is found that the magnetic anisotropy constant is in the order of 10⁵ J m^–3 which is higher than the value of the bulk iron and increases with the increase of reducing temperature.     

InGaAsP/InP有源双稳放大器的实验研究

本文报导了室温下F—P型InGaAsP/InP双异质结半导体激光放大器的双稳态效应,放大器的增益为20dB。     

B—ISDN宽带UNI信令点到多点配置的实现

本文根据ＩＴＵ－Ｔ最新的Ｑ．２９７１协议，以及笔者所从事的实际课题，提出一整套Ｂ－ＩＳＤＮ第三层ＵＮＩ信令的软件实现策略，其特点是能同时满足用户对点到点以及点到多点广播这两种通信方式的要求，而且可以动态配置。     

自韧Si3N4陶瓷的显微结构及其性能研究

利用热压的方法制得室温断裂韧性和抗弯强度分别为１１．２ＭＰａ·ｍ￣（１／２）、８２３ＭＰａ，高温（１３５０℃）断裂韧性和抗弯强度分别为２３．９ＭＰａ·ｍ￣（１／２）、６３０ＭＰａ的自韧Ｓｉ＿３Ｎ＿４陶瓷。研究了显微结构和力学性能之间的关系。结果表明：玻璃相的含量、β－Ｓｉ＿３Ｎ＿４的长径比等对性能有重要影响。分析了自韧Ｓｉ＿３Ｎ＿４陶瓷的增韧机理，通过ＳＥＭ明显观察到Ｓｉ＿３Ｎ＿４中存在裂纹偏转、分支和β－Ｓｉ＿３Ｎ＿４拔出现象。     

二(二甲苯基)丙烷合成工艺的研究

二氯丙烷(DCP)与二甲苯在混合金属氯化物催化剂(HD90)作用下合成二(二甲苯基)丙烷,生产过程简单,产品收率高。在60—80℃的温度下,二甲苯与二氯丙烷摩尔比为6∶1,HD用量50克/摩尔DCP的条件下反应5—6小时,二(二甲苯基)丙烷的收率可达88％以上。