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961.
不同于传统的非制冷红外成像技术,提出了基于微电子机械系统(MEMS)的新概念光学读出非制冷红外成像技术。它的光学读出系统基于空间刀口滤波原理,具有高灵敏度、高分辨率和高抗震性等优点,但同时也受到了反光板的弯曲变形、粗糙度等复杂因素的影响。在大量实验数据的基础上,利用夫琅禾费近场衍射理论,建立了复杂因素下光学灵敏度的理论分析模型,详细分析了刀口滤波位置、反光板的长度、曲率半径、粗糙度、LED光源的强度以及扩展宽度等对光学灵敏度的影响,并提出了通过极限操作使系统的光学灵敏度最大化的光学优化方法。 相似文献
962.
Xingyu Mao Zhijian KeWeidong Zou Qiubao LinZhijie Qin Yan Wu 《Journal of magnetism and magnetic materials》2012,324(4):389-393
The dynamic magnetization processes of nanocrystalline Fe80Ge3Nb10B7 alloys after annealing at different temperatures are studied through the permeability spectroscopy. Three steps of crystallization are found when amorphous Fe80Ge3Nb10B7 alloys are heated from 300to 1200 K. The dominant magnetization process varies with different annealing temperatures. Domain wall bulging is the main magnetization mechanism under weak applied field. When the applied field exceeds pinning field Hp, the depinning-involved domain wall displacement occurs. Different annealing temperature results in different Hp. The lower value of μ′ and high relaxation frequency after heating at 923 and 973 K are due to the strengthened domain wall pinning and the increase of magnetocrystalline anisotropy. 相似文献
963.
p-Sulfonated calix[6]arene modified graphene has been firstly synthesized and provided as a 'turn on' probe for L-carnitine through monitoring the fluorescence signal both in vitro and in living cells. 相似文献
964.
965.
Xiao Y Yang L Mao P Yuan J Deng Y Qu L 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2012,85(1):298-302
In the present work the feasibility of β-cyclodextrin in complexation was explored, as a tool for improving the solubility and biological ability of daidzein derivatives. A series of phosphorylated daidzein derivatives featuring different chain lengths were synthesized through a modified Atherton-Todd reaction and their inclusion complexes with βCD were prepared by coprecipitation method. The inclusion complexation behavior was studied by fluorescence, UV, FT-IR, MS and (1)H NMR. The results showed that only phosphorylated daidzein derivative carrying small substituent group ((C(2)H(5)O)(2)PO) entered the cavity of βCD and formed 1:1 inclusion complex. The formation constant was 175(mol/L)(-1). 相似文献
966.
PET/silica nanocomposite fibers of high quality were fabricated from electrospinning by choosing appropriate surface modification of inorganic fillers, solution properties, and processing conditions. The existence of an immobilized layer around silane-modified silica particles in PET fibers was verified by Fourier transform infrared spectroscopy, the results of which confirm previous thermal analysis studies. The influence of silica particles on the crystal growth during isothermal crystallization as well as the phase structure of the crystallized nanocomposite fibers were examined using differential scanning calorimetry. The PET crystallization rate increases significantly with increasing silica content, which indicates that the silica nanoparticles act as an efficient nucleating agent to facilitate PET crystallization. Using Avrami analysis, for the first time, preferred 1-D crystal growth was confirmed for geometrically confined nanocomposite fibers. Addition of silica particles makes the crystal growth more likely to occur in a 1-D manner. 相似文献
967.
Jia-jia Ji Hui Sun Xiang-yu Mao Wei Wang Xiao-bing Chen 《Journal of Sol-Gel Science and Technology》2012,61(2):328-331
The Bi5FeTi3O15 (BFTO) films of layered structure have been fabricated on Pt/Ti/SiO2/Si substrates by the sol–gel method. The thermal decomposition behaviors of precursor powder were examined using thermo-gravimetric
and differential scanning calorimeters analysis. The optimal heat treatment process for BFTO films were determined to be low-temperature
drying at 200 °C for 4 min and high-temperature drying at 350 °C for 5 min followed by annealing at 740 °C for 60 min, which
led to the formation of compact films with uniform grains of ~300 nm. The structural, surface topography, ferroelectric and
magnetic properties of the films were investigated. The remnant polarization (2P
r) of BFTO thin films under an applied electric field of ~550 kV/cm are determined to be 67.5 μC/cm2
. Meanwhile, the weak ferromagnetic properties of the BFTO films were observed at room temperature. 相似文献
968.
Jiaoran Meng Xiaodong Zhang Hao Wu Jing Bu Chenyi Shi Chunhui Deng Yu Mao 《Analytica chimica acta》2012
Conditioned place preference (CPP) is a widely used model to explore the mechanism of context-dependent learning. In this work, we developed a GC–MS method to investigate the metabolites in mice brain which was used to study the mechanism of context-dependent learning associated with rewarding effect of morphine. Metabolites were extracted from brain tissues and derivatized followed by analysis by gas chromatography/mass spectrometry (GC–MS). In total, 69 peaks were identified as known compounds. By a Wilcoxon ran sum test with p value ≤0.05, 21 metabolites were selected and considered as the potential biomarkers of morphine in mice brain. Using principal component analysis (PCA) and receiver-operator characteristic (ROC) curves, a model was constructed with a combination of these 21 metabolic markers. Multivariate statistics of the model yielded separation between the two groups with an area under the curve value of 0.947. Some metabolites were further discussed in detail about their pathway. Results showed that our technique can be successfully applied to profile for biomarkers and in understanding molecular mechanisms of drug abuse. 相似文献
969.
Xiaobing Cheng Mao Liang Siyuan Sun Yongbo Shi Zijian Ma Zhe Sun Song Xue 《Tetrahedron》2012,68(27-28):5375-5385
Diverse fused thiophenes with electron-rich and electron-deficient blocks have been synthesized and employed as the π-conjugated spacers of organic dyes for the dye-sensitized solar cells (DSSCs). The effects of these fused thiophenes were investigated by their absorption spectra, electrochemical and photovoltaic properties. For a typical device a maximum power conversion efficiency of 6.11% was obtained under simulated AM 1.5 irradiation (100 mW cm?2): a short-circuit current (JSC) of 14.47 mA cm?2, an open-circuit voltage (VOC) of 670 mV, and a fill factor (FF) of 0.63. 相似文献
970.
A highly efficient catalyst system assembled from enantiomerically pure diaminocyclohexane and Ni(OAc)(2) is, for the first time, used to catalyze the cascade Michael-Henry reaction of various diones and substituted nitroalkenes. A series of polyfunctionalized bicyclo[3.2.1]octane derivatives containing four stereogenic centers are prepared with excellent enantioselectivities (up to >99% ee) and diastereoselectivities (up to 50 : 1 dr) with high yields. In addition, via this chiral diamine-Ni(OAc)(2) catalyst system, the base-induced epimerization leading to the decrease of stereoselectivity can be prevented. 相似文献