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1.
In many generic combustion models, one finds that a combustionwave will develop with a specific wave speed. However, thereare possible initial temperature profiles which do not evolveinto such waves, but rather die out to the ambient temperature.There can exist, in some models, a clear distinction betweenthose initial conditions that do evolve into combustion wavesand those that do not; this is sometimes referred to as thewatershed initial condition. When fuel consumption is consideredto be negligible, analytical methods can be used to obtain theexact watershed. In this paper, we consider the problem of determiningpseudo-watersheds and ascertaining the relationship betweenthese pseudo-watersheds and the exact watersheds. In the processa novel weight-function approach for infinite spatial domainsis developed.  相似文献   
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利用激光蒸发团簇源产生Wn团簇束,团簇束通过一个充有N2气体分 子的低压反应池,利用飞行时间质谱探测反应产物,在类单次碰撞条件下研究了W+10 -W+50和N2分子的反应性,在室温条件下测量了N2分子与W+n团簇反应的 反应几率。团簇尺寸在10~26原子的团簇与N2分子的反应几率与团簇尺寸有很强的相关性 ,对n=16,22,23的团簇具有比较高的反应性。W+n与N2分子的反应性与Wn与N 2分子的反应性显示出相似的规律性。  相似文献   
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In this work we discuss the use of multilayer stacked structures (p(SiC:H)/i(SiC:H)/n(SiC:H)/p(SiC:H)/i(Si:H)/n(Si:H)) sandwiched between two transparent conductive contacts as colour sensing devices. The thickness and the absorption coefficient of both front and back p–i–n cells were specifically designed in order to achieve simultaneously high blue collection and red transmittance in the front cell and full green absorption and high red collection in the back cell. Electric and optical sensing methods were used for measuring the current–voltage characteristics and the spectral sensitivity, under different experimental conditions. Results show that the spectral sensitivity of the device is strongly modulated by the applied voltage, which allows colour selectivity. The results were supported by a physical model.  相似文献   
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This paper reports about a study of the local plasmonic resonance (LSPR) produced by metal nanoparticles embedded in a dielectric or semiconductor matrix. It is presented an analysis of the LSPR for different nanoparticle metals, shapes, and embedding media composition. Metals of interest for nanoparticle composition are Aluminum and Gold. Shapes of interest are nanospheres and nanotriangles. We study in this work the optical properties of metal nanoparticles diluted in water or embedded in amorphous silicon, ITO and ZnO as a function of size, aspect-ratio and metal type. Following the analysis based on the exact solution of the Mie theory and DDSCAT numerical simulations, it is presented a comparison with experimental measurements realized with arrays of metal nanospheres. Simulations are also compared with the LSPR produced by gold nanotriangles (Au NTs) that were chemically produced and characterized by microscope and optical measurements.  相似文献   
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Binding of chlorpromazine (CPZ) and hemin (Hmn) to human (HSA) and bovine (BSA) serum albumin was studied by fluorescence quenching technique. Intrinsic fluorescences of BSA and HSA were measured by selectively exciting their tryptophan residues. Gradual quenching was observed by titration of both proteins with CPZ and Hmn. CPZ is a widely used anti-psychosis drug that causes severe side effects and strongly interacts with biomembranes, both in its lipidic and proteic regions. CPZ also interacts with blood components, influences bioavailability, and affects the function of several biomolecules. Albumin plays an important role in the transport and storage of hormones, ions, fatty acids and others substances, including CPZ, affecting the regulation of their plasmatic concentration. Hmn is an important ferric residue of hemoglobin that binds within the hydrophobic region of albumin with great specificity. Hmn added to HSA and BSA solutions at a molar ratio of 1:1 quenched about half of their fluorescence. Stern-Volmer plots obtained from experiments carried out at 25 and 35 degrees C showed the quenching of fluorescence of HSA and BSA by CPZ to be a collisional phenomenon. Hmn quenches fluorescence by a static process, which specifically indicates the formation of a complex. Our results suggest the prime binding site for CPZ and Hmn on both HSA and BSA to be near tryptophan residues.  相似文献   
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针对现有Web使用记录挖掘方法发现的知识和规则存在不精确或不完全的问题,提出了一种改进的基于粗糙近似的Web事务聚类算法.该算法首先对原有算法得到的每个类,用关系矩阵找出在这个类中不满足传递性的对象,然后在该对象的集合(类)上用关系矩阵找出在这个类中不满足传递性的对象,再对每个类进行分割,使其满足关系R的传递性,克服了现有算法不满足关系的传递性和在某些情况下得到的结果不准确的缺点.  相似文献   
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Thiosemicarbazones are known to be active against different pathogenic microorganisms including Trypanosoma cruzi, the etiological agent of Chagas disease. In the search for new therapeutic drugs against this illness, the complexes [Mn(H4NO2Fo4M)2Cl2] (1), [Mn(H4NO2Ac4M)2Cl2] (2) and [Mn(H4NO2Bz4M)2Cl2] (3) of N4-methyl-4-nitrobenzaldehyde thiosemicarbazone (H4NO2Fo4M), N4-methyl-4-nitroacetophenone thiosemicarbazone (H4NO2Ac4M) and N4-methyl-4-nitrobenzophenone thiosemicarbazone (H4NO2Bz4M) were obtained and screened in vitro against bloodstream and intracellular forms of T. cruzi. H4NO2Fo4M, H4NO2Ac4M and their Mn(II) complexes displayed poor effect on bloodstream trypomastigotes, with IC50 values ranging from 68 to >200 μM. However, although H4NO2Bz4M was also not active, its corresponding Mn(II) complex presented high effect on this T. cruzi form, with an IC50 value of 19 μM. The effect of complex (3), against trypomastigotes of T. cruzi supports further in vitro as well as in vivo studies.  相似文献   
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