被动直升机声信号波达方向估计

在分析直升机声信号和背景噪声特点的基础上,提出了1种适合于被动单直升机 目标声信号波达方向(DOA)估计的方法。首先在1帧时间内利用傅立叶变换估计直升机声信 号基频,然后用查表获得的投影矩阵滤除不需要的频率成分,最后用波束形成估计到达角。方 法运算量适中,精度较高,通过对采录的1架某型号直升机声信号的分析验证了该算法的有效 性。     

场面监视雷达设备监控与状态采集系统的研发

机场场面监视雷达是专门用于对机场场面上移动的飞行器和机动车辆进行监视的设备,目前在我国的北京国际机场、上海浦东国际机场、广州新白云国际机场都有应用。本文主要对丹麦Terma公司生产的场面监视雷达的监控数据通信协议进行研究,在此基础上采用C#编程语言实现针对该设备的监控与状态采集终端的开发。文中的研发思路对民航空管同类型设备的监控与采集系统的研发有一定的借鉴作用。     

Cyanate Ester-Based Encapsulation Material for High-Temperature Applications

Cyanate ester resin-based composite materials have been proposed as potential encapsulants for high-temperature applications. The objective of this study is to develop a cyanate ester-based encapsulant, which can also serve as a flip-chip underfill as well as for traditional encapsulation. Two different materials, quartz and alumina fillers, have been studied. The impact of shapes and sizes of the fillers on the overall thermomechanical properties has been investigated. The adhesion strengths of the materials to the ceramic substrate, Kovar lid, and silicon die have also been characterized. The modulus of the resin and the shape of the fillers play a pivotal role in minimizing thermal stress, generated by coefficient of thermal expansion mismatches. Smaller filler particles were found to have better adhesion to the cyanate ester resin. The high-temperature performance of the cyanate ester-based encapsulants was evaluated by thermal aging at 300°C for up to 500 h.     

注入条件对SIMOX材料的影响

利用ＲＢＳ和ＴＥＭ技术分析研究了不同注入剂量、注入方式（单重注入，多重注入）对ＳＩＭＯＸ材料各层结构的影响，特别着重研究了Ｓｉ／ＳｉＯ２界面过渡区受注入条件的影响。结果表明，在注入剂量相同的情况下，多重注入不仅能改善顶层单晶、ＳｉＯ２绝缘层的质量，而且能显著减小Ｓｉ／ＳｉＯ２界面过渡区宽度。     

CMOS／SOI电路模拟与参数提取

ＳＯＩ－ＭＯＳＦＥＴ主要模型参数得一致的提取，因而该模型嵌入ＳＰＩＣＥ后能保证ＣＭＯＳ／ＳＯＩ电路的正确模拟工作，从ＣＭＯＳ／ＳＯＩ器件和环振电路的模拟结果和实验结果看，两者符合得较好，说明我们所采用的ＳＯＩ ＭＯＳＦＥＴ器件模型及其参数提取都是成功的。     

一种新型的寻呼网络——虚拟寻呼网

随着无线寻呼的发展 ,寻呼联网成为寻呼业发展热点之一。本文介绍了一种新型寻呼网络—虚拟寻呼网 ,它组建、管理及扩容都很简便 ,同时建网成本低     

超快荧光光谱的光谱特性和时间特性的研究

飞秒脉冲激光器和时间分辨率优于 2ps的条纹相机相结合测量超快荧光光谱的光谱特性和时间特性 ,分析了荧光光谱的产生 ,给出了时间分辨荧光光谱的测量 ;实际测量了一种有机光盘存储记录材料偶氮染料掺杂薄膜的时间分辨荧光光谱和荧光寿命。     

Frequency estimation of sinusiode from wideband using sub-Nyquist sampling

A novel frequency estimation algorithm for wideband signal with sub-Nyquist sampling is proposed in this paper. With the aid of information provided by the auxiliary delayed sampling channel and the aliased frequency estimation for wideband signal with sub-Nyquist sampling, the frequency aliasing due to sub-Nyquist sampling can be solved. This method can reduce the complexity of the overall hardware at the cost of an auxiliary sampling channel. Furthermore, in order to alleviate the computation burden for its practicability, a more simplified algorithm is put forward and its validity is proved by our numerical simulation results. The Cramer-Rao Lower Bound （CRLB） of the frequency estimation is also derived at the end of this paper.     

控轧过程中Nb,V,Ti碳氮化物的应变诱导等温析出

利用STEM,EDAX,新的萃取复型技术和相分析方法,研究了Nb钢,V钢、Nb-V钢和Ti-V-Nb钢中的Nb,V,Ti碳氮化物在控轧过程中的应变诱导等温析出和颗粒粗化的规律。     

杨木爆破浆作新闻纸配浆的初步研究

进行了杨木爆破浆配抄新闻纸的研究，杨木爆破浆取代马尾松化学浆配抄新闻纸后除撕裂度略有下降外，裂断长、拉毛速度、印刷密度、透印值等都有明显改善