Modeling of the Temporally and Spatially Modulated Fourier Transform Imaging Spectrometer working in orbit

Temporally and Spatially Modulated Fourier Transform Imaging Spectrometer (TSMFTIS) is a new kind of imaging spectrometer and is applicable in remote sensing. Compared with Temporally Modulated Imaging Interferometer and Spatially Modulated Imaging Interferometer, it employs immovable parts and abandons slit. Based on the analysis of its physical theory, optical principle, data gathering and processing, the mathematical model of the TSMFTIS working in orbit is proposed in this paper. The model is comprised of different function blocks, such as fore-optics, interferometer and so on. For simulation, a big remote sensing image is utilized as ground scene, and a conversion which is similar to color mode conversion from RGB to Lab is made to produce artificial spectra of various ground objects. At last, a validation experiment is performed with real-world spectra of four pieces of colorful cloths by using a commercially available spectrometer.     

基于相位一致性的实时压缩跟踪方法

针对基于压缩感知的目标跟踪算法在跟踪过程中,光照剧烈变化引起跟踪不稳定或跟踪失败的问题,本文提出了一种基于相位一致性的改进跟踪方法.该方法利用相位一致性图像特征对光照变化不敏感的特点,首先对样本搜索区域内的图像进行相位一致性变换,然后再提取变换后相位一致性图像的特征,将其用于分类器中来确定目标位置.实验结果表明,该方法在目标受到光照剧烈变化影响的情况下具有很强的适应性,在目标大小为50pixel×55pixel时平均处理帧频可达22fps.与已有基于压缩感知跟踪算法相比,该算法在光照变化剧烈的情况下仍具有很好的鲁棒性,而且在目标尺度和纹理发生一定变化的情况下跟踪稳定.     

Computer Simulation of a 3-D Sensing System with Structured Illumination

A computer simulation system of three-dimensional sensing with structured illumination is presented. It includes the generation of deformed fringe patterns from 3-D shapes and the reconstruction of 3-D shapes, conversely. Some experimental results of the deformed fringe pattern and the reconstructed object shapes are presented. We have also discussed the effect of some major system parameters on the measurement results and considered how to correct these parameters according to the measurement result of the standard plane. Using this simulation system, the major system parameters: environmental conditions, measurement accuracy and algorithm evaluation of the 3-D shape measurement system based on PMP, FTP, SPM, etc., can be researched. © 1997 Elsevier Science Ltd. All rights reserved.     

Viscometric Estimation of Unperturbed Chain Dimensions of Polymers

A new expression is proposed to determine the unperturbed dimensions of coil-like polymers viscometrically by use of the Flory and Kratky expression. The unperturbed dimensions so estimated are compared with the results obtained by using different expressions available in the literature. The results are comparable even for stiff chain polymers. The data obtained under theta conditions also fit this expression very well. The effect of molecular weight, its distribution, and that of the solvent has also been studied. It is concluded that the unperturbed dimensions are independent of molecular weight and solvent but depend on the heterogeneity of the system.     

Synthesis,photophysical and NMR evaluations of thiourea-based anion receptors possessing an acetamide moiety

The synthesis and photophysical evaluation of three diaryl thiourea-based anion receptors (4–6) for comparison with their urea counterparts (1–3) is outlined. These anion receptors posses an acetamide functionality on one of the aryl groups and an electron-withdrawing CF₃ group on the other. By varying the position of the acetamide group, in the o-, m- and p-positions of 4–6, respectively, the anion binding ability was both tuneable and found to be, in some cases, significantly different from that seen for the urea analogues 1–3. The binding affinities of the receptors 4–6, as well as the binding stoichiometries, were evaluated using UV–vis absorption spectroscopy in MeCN. However, these receptors were not sufficiently emissive to quantify the anion recognition using fluorescence. The results confirmed strong binding of these receptors to anions such as fluoride, acetate, phosphate, pyrophosphate and chloride. Nevertheless, the overall results obtained did not conform to the anticipated trends seen for 1–3, which is most likely due to the enhanced binding affinity of the thiourea analogues 4–6. The binding interactions were also investigated by using ¹H NMR which confirmed that these receptors interacted with the anions in a stepwise manner, where the primary anion binding interaction occurred at the thiourea side, which led to an activation of the acetamide moiety towards the second anion binding interaction, an example of an allosteric activation mode.     

一种铽配合物用于水溶液中二甲硝咪唑和四环素的检测

选用(1,1'':3'',1″-三联苯)-3,3″,4'',5,5″,6''-六羧酸(H₆L)为配体,在溶剂热条件下,与Tb³⁺离子反应得到配合物[Tb (L)_0.5(H₂O)₂]·7H₂O (1)。通过单晶X射线衍射、粉末X射线衍射、红外光谱、元素分析、热重分析对该配合物的结构和组成进行了表征,同时,对其荧光性质进行了研究。结果表明:该配合物属于正交晶系,Cmca空间群,a=2.661 61(7) nm,b=1.421 03(4) nm,c=2.109 88(6) nm。拓扑计算表明配合物1是一个新颖的(6,6)-连接的三维网络结构,符号为(4⁸.6⁶.8)(4⁹.6⁶)。该配合物具有强的荧光发射,可以快速检测水溶液中的二甲硝咪唑和四环素且灵敏度高、检出限低、可回收性好。通过实验和密度泛函理论相结合,揭示了荧光猝灭机理。     

In Situ Generation of Formaldehyde and Triphenylphosphine from (Hydroxymethyl)triphenylphosphonium and Its Application in Wittig Olefination

The reaction of (hydroxymethyl)triphenylphosphonium with benzylic or allylic halide under basic conditions at room temperature affords terminal alkenes in 61–89% yields. In this reaction, both formaldehyde and triphenylphosphine are in situ generated from (hydroxymethyl)triphenylphosphonium and further undergo Wittig olefination with benzylic or allylic halide.     

碳一化工路线制备乙二醇研究进展

乙二醇(EG)是一种重要的化工原料,主要用来生产新型聚酯纤维.近年来由于我国聚酯产业发展迅速,极大的推动了对乙二醇的需求.碳一化工路线以资源丰富、价格便宜的天然气或煤为原料合成乙二醇,有着诱人的工业化前景.综述了以合成气为原料合成乙二醇的研究进展,包括合成气直接合成法、甲醛羰化法、CO偶联法、甲醛氢甲酰化法以及甲醛缩合法等.     

夜视战场环境视觉传感信息采集系统设计

夜视战场环境视觉传感信息的实时获取是跟踪夜视战场图像处理分析的前提,针对夜视战场环境的复杂特征,设计了夜视战场环境视觉传感信息采集系统,分析了系统的总体结构,系统硬件主要包括视觉传感器、传感器控制卡和扩展卡、图像采集与存储以及信号调理电路,给出了系统采集节点的程序设计流程以及传感信息采集的具体程序代码实现过程。实验结果说明,所设计系统可有效采集到夜间军事战场中的传感信息,并且具有较高的采集精度。