烯烃不对称双羟化及其反应机理的研究进展

本文综述了近年来四氧化锇催化烯烃不对称双羟化及其反应机理的研究进展。Sharpless等对烯烃双羟化机理的透彻研究导致了不对称双羟化方法的优化。     

中国南海海绵Seletta tenuis Lindgren中24-亚甲基-27-甲基胆甾醇的结构鉴定

自七十年代以来,已从海绵中发现了许多结构独特的、具有强烈生理活性的新化合物,有些已发展成为特效的药物。我们在研究中国南海海绵生物活性成分的过程中,从南海海绵Seletta teuuis Lindgren中分离出24-亚甲基-27-甲基胆甾醇(1)。虽然这个化合物已由De Luca等于1972年从海绵(Aplysina aerophoba)中发现了它。次     

吡咯基金属络合物的制备及其在有机合成中的应用

本文综述了近年来吡咯基金属络合物的研究进展, 详细讨论了σ~N-、σ~C-、π-型吡咯基金属络合物的制备方法, 以及各类吡咯基金属络合物在有机合成中的应用。     

人γ晶体蛋白的一级结构测定 1.γ晶体蛋白的分离提纯及其顺序测定方法(GC/MS法)的研究

成功地从人眼晶体中分离出单纯组分的γ晶体蛋白,对γ晶体蛋白的纯度、相对分子质量、氨基酸组成、N末端氨基酸组成等进行了测定,利用酸水解法和酶解法对γ晶体蛋白进行了水解和酶解条件的摸索、找出了使γ晶体蛋白断裂成适合于GC/MS联用仪进行结构测定的肽段的裂解条件。对进行氨基酸顺序测定的GC/MS法化学衍生化条件作了一系列的摸索,找出了化学衍生化的合适条件。对衍生化过程中的一些影响因素也进行了探讨。     

GC/MS SIM法快速测定酒中的游离脂肪酸

本文介绍一种简单、快速、灵敏、直接分析酒中游离脂肪酸的测定方法。用涂有OV-17熔融石英毛细管柱。选择游离脂肪酸质谱图中的基峰离子m/z 60进行SIM检测。定量测定了茅台酒、珍酒及鸭溪窖酒中十二种游离脂肪酸。     

混合溶剂火焰原子吸收法直接测定原油中的镍

混合溶剂火焰原子吸收法直接测定原油中的镍刘广东袁存光张丙华刘文钦（石油大学（华东），山东东营２５７０６２）彭力（中国石油天然气总公司环保处，北京１００７２４）关键词原油，混合溶剂，无机盐标准，原子吸收法，镍测定原油中，微量元素镍、钒、铁、铜的存在对...     

Dehydrogenation activity and structure of polyaniline supported heteropolyacid catalysts

Polyaniline(PAN) supported H₆P₂W₁₈O₆₂(PW) , H₃PMo₁₂O₄₀ (PMo) and H₄PMo₁₁VO₄₀(PMoV) catalysts were prepared and their activities for hexanol conversion were tested. IR, XRD, ICP and SEM measurements proved that the heteropolyacids (HPA) could be supported on this type of polymer. The PAN supported HPA catalysts exhibit higher redox activities and low acid-base activities for the hexanol conversion. The redox activities increase with increasing amount of the heteropolyacid. Substitution of Mo ion by V ion results in an increase of redox activities of the catalysts. This revised version was published online in June 2006 with corrections to the Cover Date.     

Transition metal substituted tungstophosphoric compound catalyzed oxidation of hexanol to hexanal with hydrogen peroxide

Summary The oxidation of hexanol in the presence of the Keggin-type heteropoly compounds (HPCs) H₃PMo_nW_12-nO₄₀ (denoted as PMo_nW_12-n, n=0,1) and Na₅PW₁₁ZO₃₉ (denoted as PW₁₁Z, Z = Mn, Fe, Co, Ni, Cu and Zn) was carried out to produce hexanal and hexanoic acid. The reaction was conducted in tert-butanol (t-BuOH), using cetylpyridinium bromide (CPB) salts of HPA and 15% aqueous H₂O₂ as oxidant under mild condition. The PMoW₁₁ catalyst showed higher hexanol conversion of 25%, the lowest selectivity to hexanal of 64.4% and an efficient utilization of H₂O₂ of 34%. Over the transition metal substituted PW₁₁Z catalysts decomposition of H₂O₂ was rapid. For these PW₁₁Z catalysts, the efficient utilization of H₂O₂ decreased to 9% or even lower. By means of IR, UV-visible and GC-MS techniques the catalysts were characterized.     

Compare study between smoothing efficiencies of epicyclic motion and orbital motion

The smoothing efficiencies of epicyclic motion and orbital motion in CCOS (computer controlled optical surfacing) were compared. CCOS polishing can smooth out mid-to-high spatial frequency errors which are smaller than tool size on optical mirrors due to the rigidity of polishing tools. The smoothing efficiencies of epicyclic motion and orbital motion with pitch lap and RC lap were compared and the result proved pitch lap with epicyclic motion smoothed ∼1.6 times faster than pitch lap with orbital motion while RC lap with epicyclic motion smoothed ∼1.85 times faster than RC lap with orbital motion.