一类椭圆型方程的多重解

利用极小极大方法获得了一类Dirichlet问题多重解的存在性结果.     

基于PC机的线阵B超诊断系统的研究与设计

介绍了一种由B超成像前端电路结合PC机组成的新型线阵B超诊断系统。该系统实现了数字扫描变换（DSC）、测量诊断、伪彩色显示、大容量存储和诊断报告编辑功能。以微机CRT作为图像显示器，以较低的价格获得了高档B超仪的图像显示质量，并提供了比一般低档B超诊断仪强大得多的诊断功能。     

Modification of Absorption of a Bulk Material by Photonic Crystals

We show theoretically that it is possible to modify absorption of a bulk absorbing material by inserting another non-absorbing dielectric slab periodically to form one-dimensional photonic crystals.It is found that,for frequencies within photonic bandgaps,absorption is always suppressed.For frequencies located at photonic bands,absorption can be suppressed or enhanced,which depends on the relative values of the real refractive index of the absorbing and non-absorbing dielectric layers.     

Fluorescence Microscopy of Nanoscale Silver Oxide Thin Films

The experimental conditions for photoactivated intermittent fluorescence from nanoscale silver oxide were studied with fluorescence microscopy.Strong fluorescence was observed from the Ag2O particles with size of 10-20nm excited with both blue and green light .We observed the saturation of Photoexcitation with blue light and explained the experimental results using the model of agglomeration of silver atoms to form small clusters and the fluorescence of Ag2 and Ag3 clusters.     

像增强器用中波红外辐射可激励的新型荧光材料

1 引言目前,许多研究都集中于研制各种用途的中波红外成像系统。这些应用从工业用热成像一直扩展到探测车辆、导弹等的军用热成像。可反映中波红外成像目前技术水平的是加工碲镉汞、锑化铟等半导体探测器的线阵或面阵,并把它们组装到一适当光学成像系统。但是,材料和器件的产额低,这种器件不仅制作难而且成本高。本文介绍一种加工成本低用于中波红外成像的新型探测介质,具体地讲,这种新介质是一种可将中波红外     

POROSITY CALCULATION OFMIXTURES OF FIBROUS PARTICLES

The initial forming of fiber blend to high green density, i.e. the packing of fibrous particles, is important to the reinforcement of composite materials. It is very useful to develop a general predictive method for the optimum selection of particle mixtures for the property control of ceramic or composite products. This paper presents such a mathematical model developed on the basis of the similarity analysis between the spherical and non-spherical particle packings and assesses its applicability to the packing of fibrous particles with discrete and/or continuous length distributions. The results indicate that the model can predict this packing system well and hence provide an effective way to solve various packing problems in the composite materials processing.     

Cr^4＋：YAG可饱和吸收特性测量

测量了Cr4+:YAG材料的可饱和吸收特性,用多种数据分析方法处理了实验结果,Cr4+:YAG的基态吸收截面σgs=11×10-19cm2,激发态吸收截面σes=1.2×10-19cm2。     

GaN材料系列的研究进展

ＧａＮ及其合金作为第三代半导体材料具有一系列优异的物理和化学性质，在光电子器件，高温大功率电子器件及高频微波器件应用方面具有广阔的前景，已成为当前高科技领域的研究重点，论述了这种材料的研究历史与发展现状，物理与化学性质，薄膜的生长方法及在光学电子和微电子器件应用于方面的研究进展。