负载型无铬超细铁基变换催化剂的制备和催化性能

 以镁铝尖晶石为载体，以过渡金属氧化物为助剂，用吸附γ－Fe2O3胶体法制备了负载型无铬铁基变换催化剂．TEM，XRD，BET和活性测试结果表明，采用胶体负载法制备的变换催化剂，其活性组分Fe3O4以分立的超细微颗粒分布在镁铝尖晶石载体表面上，颗粒之间存在一定的间隔．过渡金属氧化物NiO或V2O5能够进入Fe3O4晶格形成固溶体，起到代替氧化铬的作用，提高催化活性．负载型催化剂FeNi／MgAl2O4（m（NiO）／m（Fe2O3）＝3％）在汽／气比为1和空速为2000h－1的反应条件下，CO转化率在400和350℃时分别为95％和80％；在高空速和低汽／气比条件下也具有很好的催化性能．稳定性实验结果表明，该催化剂 具有良好的热稳定性和一定的抗硫能力．与非负载型催化剂相比，负载型催化剂具有更为优越的催化性能．     

电子探针定量分析的标准样品——几种多元氧化物单晶

在很高的温度和适宜的生长条件下,分别采用熔盐籽晶法和高温引上法生长了高质量的YAP、NAB、KTP、LN、BBO、SBN等多元氧化物单晶,它们具有优良的物理化学性能,严格的化学比,固定的组成与结构以及较好的化学均匀性和电子束轰击下的稳定性。广泛地用于激光和非线性光学领域。我们选用这些晶体为原材料研制电子探针定量分析的标准样品。经过测量和标定,这些单晶标样符合中华人民共和国国家标准GB 4930-85(电子探针显微分析标准样品通用技术条件)的规定。含有稀土元素的标样如NAB和YAP能发出绿色荧光,是电子显微术中理想的阴极发光材料。     

TaqMan-分子灯标：一种新型的荧光基因检测探针

在TaqMan及分子灯标的基础上开发了一类新型的均相荧光检测探针—— TaqMan-分子灯标(TaqMan-MB)，该探针集合了分子灯标的发夹结构及TaqMan探针降 解作用的工作原理，使检测效果更好．与实时PCR仪联用，可用于靶基因的定量检 测．     

含L－氨基酸结构的手性液晶化合物的合成及其相变行为

合成了９种具Ｌ－氨基酸衍生物结构的介晶化合物（Ｉ－Ⅲ，Ⅳａｂ，Ⅴａ，ｂ，Ⅵａ，ｂ）、４种氨基酸衍生物（Ａ１－４）和６种介晶化合物（Ｍ１－６）．新化合物（Ⅰ－Ⅲ，Ⅳａ，ｂ，Ⅴａ，ｂ，Ⅵａ，ｂ，Ａ４，Ｍ３－６）的化学结构通过ＩＲ、１ＨＮＭＲ和元素分析证实；并用偏光显微观察和ＤＳＣ分析研究了其相变行为，结果表明有８种化合物（Ｍ３－６，Ⅵａ，ｂ，Ⅴｂ，Ⅵｂ）呈现液晶相变。测定了它们的比旋光度。通过Ｘ射线衍射研究了化合物Ⅵｈ１２０～１３０℃和Ⅵｂ１７０～１８０℃的近晶结构，Ⅵｂ显，Ⅵｂ呈。测定了化合物Ⅳｂ的电滞回线，证明其具铁电性。     

Theoretical investigation of the decarbonylation of acetaldehyde by Fe+ and Cr+.

We report a comprehensive theoretical study on the decarbonylation of acetaldehyde by Fe+ and Cr+. Various intermediates, transition states, and products involved in the decarbonylation reactions are fully optimized at the B3LYP/6-311+G(2df,2pd) level of theory. The potential energy surfaces (PESs) corresponding to [M,O,C2,H4]+(M=Cr and Fe) are examined in detail using B3LYP and CCSD(T) methods, respectively. The validity of these theoretical methods is calibrated with respect to the available thermochemical data. Calculations suggest that the Cr+ mediated decarbonylation of acetaldehyde takes place in four steps on the sextet surface: encounter complexation, C-C activation, aldehyde H-shift, and nonreactive dissociation, in good accordance with the Co+ mediated decarbonylation of acetaldehyde [Zhao, Zhang, Guo, Wu, Lu, Chem. Phys. Lett. 2005, 414, 28], while for the Fe+/acetaldehyde system decarbonylation can occur on both the quartet and the sextet PESs. The quartet pathway, which experiences spin-orbit coupling between the two surfaces, is energetically more favorable; whereas along the sextet decarbonylation coordinate several high-energy barriers are revealed. The theoretical results are compared with the experimental product kinetic energy and angular distributions of decarbonylation of acetaldehyde by Fe+ and Cr+ measured using a crossed-beam technique [Sonnenfroh, Farrar, J. Am. Chem. Soc. 1986, 108, 3521].     

Molecular structure of mixed adsorption layers surfactant—polymer at a liquid—liquid interface

Isotherms of the binding of dodecyl sulfate anions (DDS^–)and Na⁺ counterions during their coadsorption with a nonionic polymer. proxanol (PR). at the interface of dodecane-water emulsions have been measured by conductometry and Na-selective potentiometry. The adsorption of DDS^– and PR is concurrent. The affinity constant of PR to the interface determined by the Langmuir model decreases as the concentration of PR increases, and the surface concentration of DDS^– tends to a nonzero limiting value at high concentrations of PR. The surface (_o) and electrokinetic () potentials at the interface have been determined at various polymer concentrations by the spin probe and electrophoresis methods. The average dielectric permeability and density of polymer segments in We adsorption layer have been determined by ESR. The lower boundary of the hydrodynamic thickness of the polymer adsorption layer at the interface has been estimated from the dependences of _o and on the ionic strength.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1653–1661, July, 1996.     

过渡金属催化的炔烃芳构化反应

综述了过渡金属催化的炔烃环三聚芳构化反应的历史沿革及最新研究进展，并 重点对含有不同电性取代基的炔烃环三聚反应、几种典型的催化体系和作用机理、 该领域的一些前沿热点作了评述．     

About the calculation of exchange coupling constants in polynuclear transition metal complexes

The application of theoretical methods based on the density functional theory with hybrid functionals provides good estimates of the exchange coupling constants for polynuclear transition metal complexes. The accuracy is similar to that previously obtained for dinuclear compounds. We present test calculations on simple model systems based on H. He and CH(2). He units to compare with Hartree-Fock and multiconfigurational results. Calculations for complete, nonmodeled polynuclear transition metal complexes yield coupling constants in very good agreement with available experimental data.     

Organic–inorganic nanocomposites prepared from fluoro-aramid and silica

Fluoro-aramid-based sol/gel-derived nanocomposites were synthesized by condensing a mixture of 4,4′-(hexafluoro-isopropylidene)dianiline and 1,3-phenylenediamine with terephthaloylchloride (TPC) in dimethylacetamide. TPC was added in slight excess to produce amide chains with carbonyl chloride end groups and then replaced with alkoxy groups using aminophenyltrimethoxysilane to develop bonding with the silica network. Mechanical, dynamic mechanical thermal, water absorption and morphological measurements were carried out on the thin hybrid films. Increase in the tensile strength and modulus was observed as compared to pristine polyamide. The thermal decomposition temperature was found in the range of 400–500 °C. The water absorption was found to be reduced with higher silica content. The glass transition temperature and the storage moduli increased with increasing silica concentration. The maximum increase in the T _g value (345 °C) was observed with 20 wt% silica. Scanning electron microscopy revealed the uniform distribution of silica in the matrix with an average particle size ranging from 8 to 50 nm.