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941.
Abstract

Infrared spectroscopy has been a workhorse technique for materials analysis and can result in positively identifying many different types of material. In recent years there have been reports using wavelet analysis and machine learning algorithms to extract features of Fourier transform infrared spectrometry (FTIR). The machine learning algorithms contain back-propagation neural network (BPNN), radial basis function neural network (RBFNN), and support vector machine (SVM). This article reviews the important advances in FTIR analysis employing a continuous wavelet transform (CWT) and machine learning algorithms, especially in the applications of the method for Chinese medicine identification, plant classification, and cancer diagnosis.  相似文献   
942.

The condensation heat transfer characteristic curves for a ternary vapor mixture of water, ethanol, and air (or nitrogen) under several ethanol concentrations and relatively low concentrations of air (or nitrogen) were measured. The effect of non-condensable gas on several different domains in the condensation curves was discussed. The effect of non-condensable gas in the domains controlled by the diffusion resistance and the filmwise condensation was not notable; whereas that in the domain dominated by the condensate resistance of dropwise mode was remarkable. Moreover, variations due to changes in non-condensable gas concentration of several characteristic points representing the curves were discussed.  相似文献   
943.
944.
ABSTRACT

The concentration of carbon dioxide (CO2) has a significant influence on the morphology of thermal decomposition products of magnesite. So, structures, stabilities and adsorption mechanisms of (MgO)m (m?=?1–6) clusters by one or two CO2 molecules were calculated by the GGA-PW91 method. The results show that the stability of the considered clusters is (MgO)m(CO2)2 clusters > (MgO)m(CO2) clusters > (MgO)m clusters by the average binding energy. Certain low-lying isomers of (MgO)m(CO2) and (MgO)m(CO2)2 clusters which have an isolated O atom are deviating from the cluster center which possess higher kinetic activity. (MgO)m clusters prefer to adsorb a CO2 molecule, while (MgO)3(CO2) clusters prefer to adsorb a CO2 molecule rather than the neighbors. Magnesite is difficult to transit to (MgCO3)2 clusters at room temperature. However, magnesite will spontaneously transit to (MgO)2 clusters and further transit to MgO crystal which need to adsorb more energy at 700?K.  相似文献   
945.
Crosslinked fluorinated polyimides (CFPI) were successfully synthesized to study and explore the effect of cross-linkage on the migration of fluorinated segments and on the adhesion strength. Characterization by dynamic thermomechanical analysis (DMA) and thermo gravimetric analysis (TGA) confirmed good thermal properties of CFPI. X-ray photoelectron spectroscopy (XPS) results showed that the ratio of fluorinated component (6FDA-ODA) concentration of the surface to the bulk decreased with the crosslink density. The water contact angle of CFPI was lower than that of non-crosslinked fluorinated polyimide, indicating that the migration of fluorinated groups to the surface was reduced by the presence of cross-linkage. Therefore, CFPI, with no fluorine segregation on the surface, exhibited excellent wetting of adherent surfaces and adhesion strength, which was proved by lap shear strength (LSS) measurements and scanning electron microscopy.  相似文献   
946.
In unified field theory we derive expressions for the electric current densities j and. We show that j and depend on the intensitiesE andH;E andH possess a common limit 1/; and Coulomb's law is not compatible with the unified theory.  相似文献   
947.
刘江涛  周云松  王福合  顾本源 《物理学报》2004,53(10):3336-3340
讨论了利用由反常色散材料构成的二维(2D)光子晶体(PCs)实现超窄带滤波(PCADOF)的原理,并对铯原子蒸气6P3/2←6S1/2谱线的反常色散曲线进行了研究,讨论利用此反常色散曲线通过2D PCs实现超窄带滤波的方法和特点,研究发现这种滤光器的带宽可达到0.002nm,这将为设计一种全新的滤波器提供指导. 关键词: 反常色散 光子晶体 超窄带滤波  相似文献   
948.
For testing the equality of normal variances with an increasing alternative, under the null hypothesis the likelihood ratio test statistic is asymptotically distributed as a mixture of chi-squared distributions. In this paper a Bartlett-type adjustment is proposed to improve the approximation of the null distribution of the likelihood ratio test statistic with an ordered alternative.  相似文献   
949.
In this paper we investigate the asymptotic behaviour of μ-averagen-widths of integral operatorK on the Wiener space, whereK is the inverse operator of an ordinary linear differential operatorL of orderm. For 1≤p.q<∞ . and forp∈[1, ∞),q∈[2, ∞) . Supported by the Fund. of Dooctoral program of NECC.  相似文献   
950.
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