正丁烷氧化制顺酐流化床催化剂的性能

 考察了前驱体制备过程中水合肼／五氧化二钒摩尔比（以下简记\r\n为n（N2H4）／n（V2O5））对催化剂性能的影响．由较高的n（N2H4）\r\n／n（V2O5）比制得的催化剂，其（VO）2P2O7相含量较多，正丁烷转化\r\n率较高．随着n（N2H4）／n（V2O5）比的减小，δ－VOPO4相的含量逐\r\n渐增多，正丁烷转化率随之升高；而顺酐选择性开始时升高，达到最大\r\n值后逐渐降低．在n（N2H4）／n（V2O5）＝0．34时制备的催化剂最佳\r\n，在丁烷浓度为4．0％、空速为500h－1及反应温度为420℃的反应条件\r\n下，顺酐收率可达49．74％．本文中细粒床催化剂有较大的操作弹性．     

基于离子液体的炭材料制备、改性及应用

离子液体因其熔点低、液态温域宽、蒸气压低、热稳定性高、电导率高、电化学窗口宽、结构可设计及对许多化合物的亲和性等系列性能而引起人们广泛关注。离子液体在炭材料制备、改性领域展示出了良好的前景及巨大的应用潜力,可直接作为碳源,经过高温炭化实现杂原子掺杂制备多孔炭材料;离子液体也可充当反应介质和致孔剂,将生物质转化为多孔炭材料;此外,由于离子液体与炭材料相容性较好,可以用于多孔炭材料改性制备炭复合材料。基于离子液体的炭材料在电催化、超级电容器、吸附分离及生物医学等领域具有潜在的应用价值。本文总结了基于离子液体炭材料的制备、改性及应用最新研究进展,并着重介绍了其在能源和环境相关领域的应用。     

Synthesis and characterisation of advanced UHMWPE/silver nanocomposites for biomedical applications

A supercritical fluid (SCF) route for facile and homogeneous introduction of silver nanoparticles into polymer hosts is described. Our focus is on ultra-high molecular weight polyethylene (UHMWPE). We demonstrate that the metallic nanoparticles have a substantial effect upon the wear and tribochemical properties of the polymer substrate.     

熔融碳酸盐燃料电池阳极材料表面改性

选择铌作为合金化元素，通过氟化物熔盐电化学表面合金化的方法对熔融碳酸盐燃料电池阳极材料镍进行表面改性，改性后的阳极材料的耐蚀性能与电催化性能均得到明显的改善。     

Dispersion state and catalytic properties of vanadia species on the surface of V_2O_5/TiO_2 catalysts

The dispersion state and catalytic properties of anatase-supported vanadia species are studied by means of X-ray diffraction (XRD), laser Raman spectroscopy (LRS), H2 temperature-programmed reduction (TPR) and the selective oxidation of o-xylene to phthalic anhydride. The almost identical values of the experimental dispersion capacity of V2O5 on anatase and the surface vacant sites available on the preferentially exposed (001) plane of anatase suggest that the highly dispersed vanadium cations are bonded to the vacant sites on the surface of anatase as derived by the incorporation model. When the loading amount of V2O5 is far below its dispersion capacity, the dispersed vanadia species might mainly consist of isolated VOx species bridging to the surface through V-O-Ti bonds. With the increase of V2O5 loading the isolated vanadia species interact with their nearest neighbors (either isolated or polymerized vanadia) through bridging V-O-V at the expenses of V-O-Ti bonds, resulting in the increase of the ra     

Oligoribonucleotides containing an aminoalkyl group at the N(4) atom of cytosine as precursors of new reagents for site-specific modifications of biopolymers

A solid-phase H-phosphonate procedure was developed for the synthesis of oligoribonucleotides containing aliphatic amino linkers with different lengths at the N(4) atom of cytosine. The hybridization properties of modified oligoribonucleotides were studied. Thermal stability of the RNA—RNA* and DNA—RNA* duplexes depends on the position of modified cytosine in the chain and the type of the duplex.     

Dehydrogenation of isobutane in the presence of carbon dioxide over supported vanadium oxide catalysts

Summary The dehydrogenation of isobutane to isobutene in the presence of carbon dioxide was carried out over supported vanadium oxide catalysts. The influence of the support on the catalytic performance was investigated. The isobutane conversion and isobutene selectivity in the presence of carbon dioxide were compared with the results obtained during the dehydrogenation reaction in the presence of helium (inert gas). The catalysts were characterized by temperature-programmed techniques (TPR, TPD-NH₃, TPD-CO₂).     

Surface modified precipitated calcium carbonates at a high degree of dispersion

Calcium carbonates of different degrees of surface hydrophobicity were obtained when sorbic acid or polyoxyethylene glycol were present during the precipitation. In the presence of trace amounts of divalent cations carbonates with high surface hydrophilicity and improved monodisperse character are obtained. Surface modification of the calcium carbonates by several proadhesive compounds can markedly improve the chemical affinity of the carbonates to polymers. Very effective are isostearoyl titanate and two polyoxyethylene compounds. Precipitated calcium carbonates modified with 2 to 3 percent (wt/wt) of isostearoyl titanate increased the tensile strenght of butadiene-styrene rubber by approximately 100%. Polyurethane is only strengthened when 30 wt/wt of a filler are introduced independently of the type proadhesive compounds. The best strength and hysteresis of polyurethanes are obtained with calcium carbonate modified with 2 percent (wt/wt) of polyoxyethylene glycol.     

Identification of formylglycine in sulfatases by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

C(alpha)-Formylglycine, the catalytic amino acid residue in the active site of sulfatases, is generated by post-translational modification of a cysteine or serine residue. We describe a highly sensitive procedure for the detection of C(alpha)-formylglycine-containing peptides in tryptic digests of sulfatase proteins. The protocol is based on the formation of hydrazone derivatives of C(alpha)-formylglycine-containing peptides when using dinitrophenylhydrazine as a matrix for matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). The hydrazone derivatives desorb and ionize with high efficiency and can be detected in the sub-femtomole range. The presence of C(alpha)-formylglycine is indicated by a mass increment of 180.13 u, corresponding to the hydrazone moiety, and also by a unique C-terminal fragment ion, characteristic of sulfatases, that becomes prominent in MALDI post-source decay mass spectra of the hydrazone derivatives.     

沸石分子筛表面烷基锡接枝反应的研究

介绍表面金属有机化学方法改性沸石分子筛的研究概况，简要总结了近年来国内外对某些重要的分子筛（如，Y型沸石，镓磷沸石，丝光沸石，MCM－41）表面接枝烷基锡的研究成果，参考文献32篇。