基于MPEG-4的网络化数字视频监控系统

讨论了当前网络数字视频监控系统的发展特点,并结合MPEG-4视频压缩格式,以实际系统为模型,介绍了基于MPEG-4网络监控的系统设计方案及其实现,并讨论了系统的局限性,提出了可行的解决方案.     

X射线荧光光谱分析氟化铈晶体中的掺杂元素钕

本文提出了用X射线荧光光谱（XRFS）定量分析氟化铈晶体中掺杂元素钕方法，对用XRFS进行晶体样品分析时的制样方法作了比较，并且对用XRFS非破坏分析晶体中的掺杂元素的方法进行了探讨。     

THE PROJECTION LINKAGE BETWEEN THE SPINAL DORSAL HORN NEURONS AND BOTH THE SOLITARY TRACT AND DORSAL COLUMN NUCLEI

Electrical stimulation of the solitary tract nucleus (SN) and dorsal column nuclei (DCN)as well as microelectrode recording from the lumbal spinal dorsal horn have been used tofind and identify the axonal projection of and the afferent innervation on the spinal neuronsof pentobarbital- anesthetized rats. A total of 92 neurons was recorded and identified mainly in laminae Ⅲ-Ⅴ of the lumbarspinal dorsal horn. Of them, 38 neurons were activated antidromically from stimulation ofboth the SN and DCN. The other 54 neurons responded synaptically to both the SN andDCN stimulations. The initial antidromic responses of 8 neurons in the first group werefollowed by one or more responses synaptically driven from the SN and/or DCN stimulation.Conduction velocities were in the range of A delta fibers, but faster in the antidromicresponses and slower in the synaptic responses. These results indicate that (i) some spinal neurons issue branched axons of larger-sizedA delta fibers and double project to both the SN and D     

DENATURATION AND PROPAGATION OF THE LOCALIZED EXCITATION IN DNA

The thermal denaturation and propagation of the localized excitation in desoxyribonucleic acid (DNA) molecules are studied in the unified way under a new Hamiltonian proposed in this work and the large amplitude motion of the DNA molecules is investigated during the propagation of the localized excitation. We discussed the nonlinear effect on the formation of the localized excitation, and showed that our model not only can reproduce the experimental results of the DNA thermal denaturation, but also can describe the process of the nonlinear localized excitation of fluctuational opening in DNA molecules.     

炉内喷钙脱硫过程数值模拟

建立了一套较为完整的对炉内喷钙脱硫过程进行模拟的方法，获得了炉内气固两相流动、温度分布、石灰石颗粒脱硫化学反应和SO2浓度分布的详细情况。石灰石颗粒的硫化反应主要发生在颗粒与烟气均匀混合之前。     

激光二极管抽运Nd:YVO4/YVO4复合晶体激光器

在高功率激光二极管(LD)抽运的情况下,对比分析了Nd∶YVO4/YVO4复合晶体和Nd∶YVO4单一晶体的激光特性.实验证明,复合晶体能够有效地降低晶体内的温度梯度,减小由端面变形带来的热透镜效应,获得比单一晶体高出许多的输出功率.采用Z型折叠腔,研究了Nd∶YVO4/YVO4复合晶体KTP倍频特性,当抽运功率为17 W时,获得了6.23 W的绿光输出,抽运光到绿光的转换效率高达37%.     

全息记录材料光致聚合物的收缩率

基于光致聚合物材料曝光后横向收缩与厚度收缩引起光栅矢量大小和方向的变化,导出了光致聚合物的收缩率与光栅读出角的布拉格偏移之间的显性关系.并设计了两步实验法,采用蓝光记录、红光动态扫描读出,分别对光致聚合物中的非倾斜光栅和倾斜光栅的布拉格偏移进行了实验测量.对自行研制的两种新型蓝光敏感光致聚合物样品,测量了其横向与厚度的收缩率,求出了材料的体积收缩率,其中经过优化配比的样品体积收缩率小于0.5%.实验也表明材料的横向收缩一般是不能忽略的.通过这种简明可靠的收缩率测量方法,可较快确定大量光致聚合物样片的收缩率,有助于找出收缩率与材料组分的关系.     

High-sensitivity Mercury Ion Detection System Using Unmodified Gold Nanorods

Hg²⁺ is one of the most universal and severe toxic metal pollutants. Here we reported a high-sensitivity and rapid method for detection of Hg²⁺. The technique was based on the localized surface plasmon resonance property of gold nanorods. Neither modification of gold nanorods nor separation of analyte was necessary. The longitudinal absorption peak of gold nanorods presented a linear blue shift as Hg²⁺ concentration increased. The blue shift of longitudinal absorption peak was due to the changes of both aspect ratio and medium dielectric constant. The sensor had a wide linear interval ranging from 285 nM to 8.00 μM, the detection limit was as low as 112 nM, and the sensitivity was 30.48 nm μM^μ1, which were comparable to the performance of the modified sensors.     

一种利用十字窗口识别红外弱小目标的新方法

为有效地识别红外图像中的弱小目标,在分析传统识别方法的基础上,提出了一种利用十字窗口识别红外弱小目标的新方法.该方法在待识别点上、下、左、右四个方向以目标大小选取四个参考点构造十字形识别窗口,根据待识别点与参考点之间的灰度梯度识别该像素点是否为目标像素.该方法无需预测背景,可以在低信噪比、强度变化剧烈的图像中获得较高的识别率与较低的虚警率.实验结果表明了该算法的有效性.     

Surface-enhanced fluorescence from copper nanoparticles on silicon nanowires

A method to enhance surface plasmon coupled fluorescence from copper nanoparticles on silicon nanowires is presented. Owing to resonant plasmons oscillation on the surface of Cu/Si nanostructure, the fluorescence peaks of several lanthanide ions (praseodymium ions, Pr3+,neodymium ions Nd3+, holmium ions Ho3+, and erbium ions Er3+) were markedly enhanced with the enhancement of maximal 2 orders of magnitude, which was larger than that caused by unsupported Cu nanoparticles. These results might be explained by the local field overlap originated from the closed and fixed copper nanoparticles on silicon nanowires.