自由大气紫外光学通信的研究

本文对紫外日盲区光谱在近距离、保密通信中的应用进行了探讨 ,并建立了紫外光学通信原理实验系统。所描述的系统是以日盲区紫外光作为信息载体的 ,用被调制的低压汞蒸汽紫外放电灯作为发射器件 ,以日盲型滤光片和光电倍增管或日盲型紫外光电倍增管作为接收器件 ,以达到在任何时间和在任何气候下完成窄频带模拟或低速数字信号的传输。由于近地表大气臭氧层的吸收 ,所以传输距离被限制在一个较小的范围内 ,构成了短距离的、秘密的、安全的和抗干扰的通信系统 ,并且不需要传统意义上的天线。由于地球大气上层臭氧的吸收作用 ,阳光中的日盲区 (2 0 0～ 2 80 nm)辐射几乎无法到达地球表面 ,因此 ,采用这个波段的光学通信系统几乎不会受到太阳光的干扰。典型的大气臭氧浓度高度分布大约在距地表 2 5 km处达到最高值 ,在海平面处有一个较低的值。相对较低的浓度值来说 ,虽然紫外辐射传输有限 ,但是具有足够远的距离 ,同时可达到安全、秘密和抗干扰的目的     

聚焦2010年度《分析化学》微流控芯片分析发展和应用

对《分析化学》2010年度有关微流控芯片分析技术作了分类,评述了各种分析技术的特点与应用情况,并与国外μTAS发展的整体趋势进行了对比.     

Angular Distribution of Synchrotron Radiation in Low Frequency

The angular distribution of energy for synchrotron radiation in low frequency band （ω 〈〈 we） is obtained by rigorously solving the Nicolo Tartaglia equation. The result shows that the critical angle increases with decreasing frequency, but it cannot exceed 90°. The relation between critical angle θc. and frequency is common covering all wavelengths. For the small angle case, it is consistent with the result obtained by Jackson. With the increase of emanative angle, the radiant intensity increases first, then decays.     

Bright Red Organic Electroluminescent Devices Based on a Soluble Rare Earth Complex Eu(TTA)_3 Phen

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Quantum probability and unified approach to quantization and dynamics

A simplified derivation of the Gudder-Hemion quantum probability formula is proposed. Defining configurations as the classical (q, p) deterministic states and generalized action as the (quantum) generating function of a canonical transformation, we obtain the usual quantization rules (for arbitrary polynomial quantities) and derive the Schrödinger wave equation on the same grounds. This approach suggests a statistical interpretation of the wave function in terms of the classical canonical transformations.     

Stability of films with nanoparticles

Numerous products (such as paints, inks, foods, and beverages) and processes (such as coating, coagulation, sedimentation, lubrication, and paper-making) depend on the stability of the liquid films separating the dispersed phase from the continuous phase in the presence of nanoparticles or surfactant micelles. Nanoparticles exhibit a tendency to form ordered layers (i.e., stratification) and particle in-layer structures in these thin films at a sufficiently high concentration, resulting in a structural force that stabilizes the dispersion. The dispersion stability depends on the film size and the nanoparticle concentration.     

Entrapment efficiencies of hydrodynamic boundary layers on rising bubbles

Flotation and separation practice shows that fine hydrophilic solids are often drawn into the froth product. The occurrence of this unwanted event in the classical froth flotation has led to the idea of using it for the separation by size of ground materials. Thus, a method for the extraction of hydrophilic fines by foaming of a suspension was proposed. The aim of the present study is to relate this phenomenon to the residence time of the particles in the vicinities of the rising bubbles. Dynamic interactions of fine solids with rising bubbles cause perturbations in the background flow field. A procedure for the mathematical modeling of these disturbance effects is proposed. The initial idea is that the particles lag behind the background bubble-driven flows. A key point is the possibility of classifying fine entities according to a general criterion, containing only parameters of the outer flow. The basic result is that there exists a range of particle and bubble dimensions for which this entrapment is optimal. The proposed model investigation gives a concise explanation for the observed capture of fine solids in many flotation and separation processes.     

Behavior of the Bergman Kernel Near Smooth Convex Boundary Points

The nontangential behavior of the Bergman metric near a smooth convex boundary point of a bounded pseudoconvex domain D ⁿ is studied in terms of its multitype.Received January 25, 2002; in revised form June 20, 2002 Published online November 18, 2002     

集值映射的 RS集逼近

本文研究了取值为 Banach空间中子集的上半连续的集值映射的 RS集逼近问题 ,给出了集值映 射用 RS集逼近的特征和唯一性结果 ,从而推广了他人的结果 .     

改进的遥感图像多种信息熵阈值分割算法

给出了一种新的图像信息量的表述方法,提出了五种基于信息熵的科学分割遥感图像的改进方法。用MATLAB对这些算法进行了实验仿真,并进行了算法性能优化。得出了各种不同算法的最佳阈值和耗时,并对它们进行了比较和分析。实验数据表明,新算法较以往的算法在分割效果和速度上都有明显的改善和提高。