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71.
结合可调谐半导体激光吸收光谱技术与计算机断层扫描技术,通过获得与实验值最适应的拟合光谱,重构本生灯燃烧火焰二维温度分布.以零均值归一化互相关和误差平方和作为指标,分析了32路测量组件的二维重构精度.结果表明,零均值归一化互相关达到0.994,误差平方和达到0.00086.采用32路测量系统实现了本生灯火焰二维温度的测量,并与热电偶测量结果进行对比.结果表明,两者之间的温度分布趋势相同,可调谐半导体激光吸收光谱测量具有更高的精度和分辨率,验证了可调谐半导体激光吸收光谱技术结合计算机断层扫描技术在测量二维火焰温度分布的可行性与精确性.  相似文献   
72.
    
In this article, we discuss the complex interpolation of various closed subspaces of Morrey spaces.We have been considering some closed subspaces of Morrey spaces in our earlier works. The main property that we need is the lattice property but in connection with the diamond spaces defined by Yuan et al.(2015), it seems to be natural to consider the convolution property as well. Our result will extend the results by Hakim and Sawano(2017) and Hakim et al.(2017).  相似文献   
73.
Yoshihiro Nishimoto 《Tetrahedron》2009,65(28):5462-3393
The coupling reactions of alkyl chlorides with silyl enolates catalyzed by InBr3, and the coupling reactions of alkyl ethers with silyl enolates catalyzed by the combined Lewis acid of InBr3/Me3SiBr are described. In both reaction systems, various types of silyl enolates were used to give corresponding α-alkylated esters, ketones, carboxylic acids, amides, thioesters, and aldehydes.  相似文献   
74.
The [3+2] cycloaddition reaction of a tungsten‐containing carbonyl ylide with methyl vinyl ether and the insertion reactions of the nonstabilized carbene complex intermediates produced have been investigated through the use of B3LYP density functional theory. The [3+2] cycloaddition reaction of the tungsten‐containing carbonyl ylide has been proven to proceed concertedly, reversibly, and with high endo selectivity. The intermolecular Si? H insertion reactions of the carbene complex intermediates have been proven to be favored over the intramolecular C? H insertion, in good agreement with experimental results. Moreover, the kinetic endo/exo ratio of the [3+2] cycloaddition reaction has been shown to determine the endo/exo selectivity of the Si? H insertion products. In addition, secondary orbital interactions involving the benzene ring and the carbonyl ligand on the metal center have turned out to strongly influence the high endo selectivity of the [3+2] cycloaddition reaction with methyl vinyl ether.  相似文献   
75.
The modulus of the complex degree of spatial coherence at the exit face of an optical fibre is determined for a quasi-monochromatic, spatially coherent source. It is found that the contribution of the cross-terms between many modes to the formulus of pointwise correlation is negligible for a highly multimode fibre in which even and odd modes are equally excited, although care must be taken when even or odd modes only are selectively excited in the waveguide. Experimental results obtained by using a Koesters prism in the wavefront reversing interferometer are also presented for a graded-index multimode fibre and a quasi-single mode fibre. Modal contents of the propagating field in the optical fibre can be successfully determined, provided that the coherence time of a quasi-monochromatic source and the path difference of the wavefront reversing system are knowna priori.  相似文献   
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The influence of temperature on the surface structure of the octadecylsilica (ODS) bonded phase was investigated with a molecular dynamics (MD) simulation. The MD simulation was applied to a molecular model consisting of three parts: amorphous silica base, dimethyloctadecylsilyl ligands and n-hexane as a mobile phase solvent. More detailed information on the effect of temperature was obtained at the low temperature region than that reported in our previous study. The motion of ODS ligands could be estimated by the mean square displacement (MSD) of the terminal carbon atoms of ODS ligands. The gauche fraction in the ODS ligand conformation can also be estimated to obtain the ligand conformation for each simulation condition in detail. It can be seen that an elevated temperature induced the more bent ligand conformation. The trend has a good agreement to that of the results experimentally observed by using various spectroscopic techniques such as nuclear magnetic resonance (NMR), Fourier-transform infrared spectroscopy (FT-IR), and Raman spectroscopy.  相似文献   
79.
The effect of UV (ultraviolet) irradiation on the adsorption of Au(III) ions on manganese dioxide and their reduction to Au(0) (gold with 0 valence state) was investigated using XPS (X-ray photoelectron spectroscopy) and 197Au M?ssbauer spectroscopy. The UV irradiation accelerated the adsorption and the reduction. From the fact that the proportion of Au(0) estimated from Au 4f XPS spectra for surface analysis was significantly smaller than that from 197Au M?ssbauer spectra for bulk analysis, we deduced that Au(0) was interpenetrated to the inside of manganese dioxide (into deeper places than about 30 A) where XPS is impossible to detect. The content of surface hydroxyl groups on manganese dioxide also increased due to the UV irradiation. The relationship between the charge in the content of hydroxyl groups and the interpenetration of Au(0) is discussed.  相似文献   
80.
A flow-injection on-line preconcentration-electrothermal atomic absorption spectrometric (ETAAS) method coupled with a coprecipitation method has been developed for the determination of lead in seawater. The combination of two preconcentration procedures, coprecipitation with iron(II) hydroxide and solid-phase extraction with a lead-selective resin, Pb-Spec, allowed the determination of lead at the ng kg(-1) level. Lead in 250 g of a sample solution was collected by coprecipitation with 10 mg of iron. The precipitate was dissolved in 25 ml of 1 mol l(-1) nitric acid; then, a 4-ml aliquot of the sample solution was introduced into the flow-injection system to preconcentrate and separate lead from iron on a Pb.Spec microcolumn. The sorbed lead was eluted with a 1.0 x 10(-4) mol l(-1) EDTA solution. The 30-microl portion of the eluate corresponding to the highest analyte concentration zone was injected into a graphite furnace. The overall enhancement factor was about 200 for 250 g of the sample. The average and standard deviation of ten blank values obtained were 1.7 ng and 0.38 ng, respectively. The recovery was 93.7 +/- 5.0% for seawater spiked with 20 ng kg(-1) lead. The proposed method is applicable to the analysis of seawater for lead at slightly higher levels.  相似文献   
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