反应条件对钌基氨合成催化剂性能的影响

用氨合成催化剂性能评价装置,研究了反应温度、压力、空速和氢氮比对以活性炭为载体的钌基氨合成催化剂活性的影响。研究表明,低于400℃时,随着反应温度降低,催化剂的活性急剧降低。随着压力升高,催化剂活性增大。但钌催化剂具有较高的低压活性,适宜低压合成氨。随着空速的降低,催化剂的活性明显提高。在空速和压力一定的条件下,最佳氢氮比随反应温度而异,并且当空速较高或反应温度较低时,氢氮比的变化对催化剂活性的影响更加明显。     

Preparation of Tin Oxide-Based Metal Oxide Particles

Tin oxide-doped hybrid particles were prepared by a wet chemical process with organic-inorganic (phenyl/silica) hybrid particles in an alcoholic solution. The phenyl/silica hybrid particles, with a diameter of ca. 790 nm were used as a new support material for tin oxide (SnO₂) particles from tin(IV) chloride. The surface of the particles was modified via nitration of aromatic groups in the particles, to promote formation of the tin oxide coating on the particles. The thickness and surface morphology of the tin oxide layer coated on the nitrated-phenyl/silica hybrid particles could be controlled by varying the tin(IV) chloride concentration and reaction time. The size and morphology of the resultant particles were investigated with field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The particles obtained were also characterised by infrared (FTIR) and solid-state ¹³C magic angle spinning nuclear magnetic resonance (¹³C-CP/MAS NMR) spectroscopy. The effect of processing parameters on the crystallinity and structure of the doped hybrids were confirmed by X-ray diffraction (XRD) patterns.     

长光路光度法测定中药材中痕量硒

本文研究了用长光路光度法测定痕量硒。在酸性溶液中，Ｓｅ（Ⅳ）催化ＫＣｌＯ３氧化苯肼成偶氮离子，继而与变色酸生成红色偶氮化合物。硒含量在１．０×１０－９～２．０×１０－７ｇ／ｍＬ范围内遵守比尔定律。巯基棉分离后，测定中药材中总硒，获得满意结果。     

Deposition of Layer－by－layer Inorganic－organic Nano－hybrid Ultrathin Films onto SBA－15

Deposition of inorganic-organic nano-hybrid ultrathin films onto mesoporous silicate materials has been proven possible by using layer-by-layer assembly method. In combination with sol-gel method, titania, subsequently dye molecules (or polymer) were successfully fabricated onto the inner wall of SBA-15. Their structures were preliminarily characterized by FTIR and solid-state UV-Vis spectroscopy, thermal analysis, and BET surface area measurements,respectively.     

气相色谱法分析生产过程中的邻甲基苯胺

气相色谱法测定工业生产过程中邻甲基苯胺及其杂质邻硝基甲苯、间甲基苯胺、对甲基苯胺的含量。4种物质的浓度与色谱峰面积呈良好的线性关系,测定结果与标准值基本一致。邻甲基苯胺、邻硝基甲苯、间甲基苯胺、对甲基苯胺的RSD分别为0.0025%、1.4081%、0.9929%、1.1365%,检出限分别为0.065、0.044、0.062、0.056mg/L。     

氧化苯乙烯和氧化二苯乙烯的区域选择性和立体选择性开环

本文报道 NaBH_4-CoCl_2可使氧化苯乙烯类化合物发生区域选择性开环,主要生成β-苯乙醇衍生物。对于氧化二苯乙烯类化合物,由于受到苯环的空间阻碍,使其开环能力减弱,如反式氧化二苯乙烯比顺式异构体更难于开环。     

一种主链含非线性光学活性基团聚合物的合成

把非线性光学(NLO)发色基团引入到聚合物主链中,既可以增大聚合物中NLO基团的含量,从而提高聚合物的宏观NLO系数,又能够提高NLO聚合物的极化稳定性。本文报道一种由酚酞环氧树脂(PPh)与对硝基苯胺(NA)得到的NLO聚合物的合成及其极化松弛。 所用酚酞环氧树脂系自制,环氧值0.427。对硝基苯胺北京化工厂产,分析纯。N,N-二甲基甲酰胺为中国医药公司售品,化学纯,用前减压蒸馏精制,乙醇、丙酮均为北京化工厂生产,分析纯。在氮气保护下将等当量的PPh与NA溶于DMF中于150℃反应6～8小时后,倒     

离子色谱法同时测定水中六种阳离子

研究了用抑制电导离子色谱法一次进样同时测定水中Li^ ,Na^ , NH4^ ,Mg^2 ,Ca^2 的色谱法条件，相对标准偏差小于0．5％，加标回收率在97．5％－104．0％。在水质分析中运用t检验法，比较了用钙、镁离子浓度计算和传统方法测定的总硬度之间是否存在显著性差异。     

Acetic anhydride as a synthetic reagent

Acetic anhydride has been used widely in synthetic organic chemistry, especially in syntheses and transformations of heterocyclic compounds. These utilities are reviewed under the following classification.