基于主元分析的人耳识别方法的研究

由于人耳图像自身的特点,基于外观形状特征如利用边缘或耳廓压痕的识别方法存在很大的缺陷,尝试采用了基于主成元(PCA)的分析方法提取人耳特征,然后运用BP神经网络进行识别。他完全克服了在以往应用外观形状特征进行识别时存在的错误率过高和特征提取预处理要求过于苛刻的问题。实验结果表明该方法实用、有效,可使识别率达到99%以上,有着广泛的研究价值和应用前景。     

基于多跳蜂窝网的合群网络模型网络容量效能分析

基于多跳蜂窝网,提出一种合群网络模型.以网络容量域模型为理论基础,分析了该模型的网络容量效能,证明了即使不考虑多播、广播和多无线的使用,合群的组织形式可以有效利用短距离多跳通信和空间复用通信,提升网络容量和一致网络容量.     

Synthesis,characterization and high-efficiency blue electroluminescence based on coumarin derivatives of 7-diethylamino-coumarin-3-carboxamide

A novel tripodal compound, tris[2-(7-diethylamino-coumarin-3-carboxamide)ethyl]amine (tren-C), and a model compound, N-butyl-7-(diethylamino)-coumarin-3-carboxamide, were synthesized and characterized by elemental analysis, infrared and ¹H NMR spectra. The structure of the model compound was characterized by single crystal X-ray crystallography. The electroluminescence devices of ITO/2-TNATA (5 nm)/NPB (40 nm)/CBP: tren-C or model compound (wt%, 30 nm)/Bu-PBD (30 nm)/LiF (1 nm)/Al (100 nm) were fabricated and characterized. The EL spectra of the devices comprising vacuum vapour-deposited films using tren-C as a dopant are similar to the PL spectrum of tren-C in chloroform solutions. At the concentration of 0.5 wt% tren-C, a blue-emitting OLED with an emission peak at 464 nm, a maximum external quantum efficiency (EQE) of 1.39% and a maximum luminous efficiency of 2 cd/A at the current density of 20 mA/cm², and a maximum luminance of 1450 cd/m² at 12 V are achieved.     

采用粒子群优化算法的无人机实时航迹规划

战场环境是动态变化的,很难预先获得全局精确的威胁信息,因此需要无人机具备一定的实时航迹规划能力.采用连续型粒子群优化(PSO)算法进行无人机参考航迹的实时规划,以最大转弯半径、步进、最短距离和回避威胁作为适应度函数的评价指标,得到代表最优航路的离散点.对算法进行了相应的仿真,结果表明该方法费时短,占用内存少,可以满足在线实时航迹规划的要求.     

模糊算法在态势评估中的应用

针对态势评估中存在的不确定性,把模糊算法应用于态势评估,建立了基于模糊算法的态势评估框架,解析态势评估的流程。同时根据不同的评估需要,建立两种不同的态势评估模型,并给出确立评估矩阵的隶属函数。通过实例把态势评估元素的条件隶属度进行量化,从而得出具体的评估矩阵,对基于模糊算法的态势评估方法的整个实现过程进行讨论。最后,通过分析评估结果比较两种模型的效能,得出更适于态势评估的模型。     

Analysis of an arbitrarily inclined slot on the ground plane of amicrostrip line

The analysis of an arbitrarily inclined slot on the ground plane of a microstrip line is presented using the spectral domain approach and reciprocity theorem. Comparison of numerical results for the special case of a perpendicular slot with other available computed and measured data shows a good agreement. It is found that the impedance level can be controlled over a wide range by varying inclination angle. Results should be useful in antenna and multilayer circuit integration applications     

多媒体技术与信息高速公路

本文叙述了信息高速公路对多媒体的依赖关系，同时对信息高速公路建设加速多媒体技术革命作了较详细的分析。指出了在信息高速公路以及多媒体技术方面所面临的技术问题，以期起专家和工程技术人员的注意。     

无源微波遥感用于地震预报的实验研究

对无源微波遥感用于地震预报在理论研究的基础上对不同岩性不同结构的岩石试件进行了加载实验，测量了岩石试件的微波辐射随载荷的变化．实验得出：岩石试件的微波辐射能量随岩石应力状态变化而显著变化；而且，不同的波段变化的幅度不同；同一波段不同极化方式的波随应力变化的变化量也不同；微波辐射能量的变化能够被卫星微波遥感探测器探测到．实验还发现，岩石试件临破裂前出现明显的微波辐射异常．     

The Cubooctahedron Shape──A Suboptimal Cell Shape for 3－Dimensional Cellular System

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Improved Hydrogen Production of Au–Pt–CdS Hetero‐Nanostructures by Efficient Plasmon‐Induced Multipathway Electron Transfer

The design of new functional materials with excellent hydrogen production activity under visible‐light irradiation has critical significance for solving the energy crisis. A well‐controlled synthesis strategy is developed to prepare an Au–Pt–CdS hetero‐nanostructure, in which each component of Au, Pt, and CdS has direct contact with the other two materials; Pt is on the tips and a CdS layer along the sides of an Au nanotriangle (NT), which exhibits excellent photocatalytic activity for hydrogen production under light irradiation (λ > 420 nm). The sequential growth and surfactant‐dependent deposition produce the three‐component Au–Pt–CdS hybrids with the Au NT acting as core while Pt and CdS serve as a co‐shell. Due to the presence of the Au NT cores, the Au–Pt–CdS nanostructures possess highly enhanced light‐harvesting and strong local‐electric‐field enhancement. Moreover, the intimate and multi‐interface contact generates multiple electron‐transfer pathways (Au to CdS, CdS to Pt and Au to Pt) which guide photoexcited electrons to the co‐catalyst Pt for an efficient hydrogen reduction reaction. By evaluating the hydrogen production rate when aqueous Na₂SO₃–Na₂S solution is used as sacrificial agent, the Au–Pt–CdS hybrid exhibits excellent photocatalytic activity that is about 2.5 and 1.4 times larger than those of CdS/Pt and Au@CdS/Pt, respectively.