Self-assembly of highly oriented one-dimensional h-WO3 nanostructures

A new self-assembled and highly oriented one-dimensional single-crystal nanostructure of WO3 with hexagonal form was successfully prepared by a mild, solution-based colloidal approach.     

内噪声作用下的随机共振算法对弱信号的检测

基于随机共振理论提出了一种简便、有效地检测弱信号的方法。在内噪声协同作用下，通过调节输入噪声信号的大小能较好地提高系统输出信号的信噪比，从而实现检测背景噪声很强的弱信号的目的。应用于模拟信号和实验信号的结果证明了方法是可行的。     

CHARACTERIZATION AND CATALYTIC PERFORMANCE OF PLATINUM SUPPORTED ON Sn-MgAl_2O_4

IntroductionSupportedPt-Sncatalystsareimpo~inthepdrileumandpthechendcalindustricsbecauseoftheirsuperiorcatalyticperformances.Forexample,Pt-Snsupportedonaneutralsupporthasbeenreportedtoexhibithighdehydrogenationselectivityanddebilitythansupportedplatinumca…     

Metallophosphites as umpolung catalysts: the enantioselective cross silyl benzoin reaction

Carbonyl polarity reversal (umpolung) has been realized employing metallophosphites as catalysts. As a result, nonenzymatic asymmetric cross silyl benzoin reactions have been achieved, giving optically active silyl ether-protected benzoin adducts. The reaction is general with respect to aryl, alkyl, and heterocyclic substrates with good to excellent yields and good to excellent enantioselectivities.     

Smith－Hieftje背景校正法空心阴极灯供电条件的选择

本文提出在原子吸收光谱测定中，采用Ｓｍｉｔｈ－Ｈｉｅｆｔｊｅ法校正背景时，空心阴极灯供电条件（即最佳宽窄脉冲电流）的选择依据和选择方法；并给出２４个常见元素的宽窄脉冲电流的选定结果。     

气相色谱法同步测定煤基油品的硫分布和沸点分布

应用火焰光度检测器与氢焰检测器偶联技术，通过对模拟蒸馏法的拓展，利用气相色谱仪同步测定了煤基油品的硫分布、沸点分布和总硫含量。结果表明：油品测定的准确性和重复性均较好，沸点分布、硫分布和总硫含量的最大相对标准偏差分别为0．47％、1．01％和2．51％。本方法需要样品量小，操作简便，比较适合于实验室煤基油品的分析研究。     

First total synthesis of a natural product containing a chiral,beta-diketone: synthesis and stereochemical reassignment of siphonarienedione and siphonarienolone

The first total syntheses of siphonarienolone and siphonarienedione are described. The development of a stereoselective synthesis of beta-diketones facilitated the synthesis of the latter compound. The synthesis of the structures proposed for the natural products afforded compounds whose spectral data did not match those of the natural products. However, the synthesis of compounds isomeric to the proposed structures at C(4) and C(5) afforded compounds identical to the natural products, thereby reassigning the stereochemistry of the natural products.     

二氧化硅表面的APTS修饰

3-氨丙基三乙氧基硅烷（APTS）修饰的二氧化硅在生物化学、分析、催化、电子学等领域具有重要的应用前景。本文对近年来APTS修饰二氧化硅的研究进展进行了简要的概述，介绍了APTS修饰二氧化硅的典型方法和APTS修饰层的表征手段，探讨了不同修饰方法可控性及对所形成的APTS层结构及稳定性的影响。     

光催化研究与发展的文献计量分析

对ＣＡ１９６１－１９９６年期间卷双期号期刊中收录的与光催化有关的各种文献进行了详细的统计,结果表明,光催化研究正处于快速的发展期,以消除环境污染为目的应用研究是该快速发展期中的主题,日本,美国,俄罗斯和中国发表文献量居世界前４位。     

Fast Determination of Phenanthrene in Soil by Gas Chromatography-Mass Spectrometry Using Chemometric Resolution and Standard Addition Method

A method for fast determination of the component in complex samples by using gas chromatography‐mass spectrometry (GC‐MS) was developed and used for quantitative analysis of phenanthrene in soils. In the method, window independent component analysis (WICA) was used for resolving the mass spectrum and non‐negative immune algorithm (NNIA) was employed for obtaining the chromatographic profile. Therefore, spectral and chromatographic information of a specific component can be obtained from the measured GC‐MS data of overlapping and high background. Six soil samples collected from different places were analyzed. The tedious pretreatments in preparing the samples and the elution in the separation were simplified for speeding up the analysis. Due to the complexity of the matrix, standard addition method was adopted for the final quantification. The applicability of the method was validated with a spiked sample and the results of the six samples are reasonable.