Ni／Al2O3催化剂上CH4／CO2重整的脉冲反应研究

报道了用脉冲反应研究Ｎｉ／Ａｌ２Ｏ３催化剂上ＣＨ４／ＣＯ２重整反应的结果。脉冲反应显示，在还原的Ｎｉ／Ａｌ２Ｏ３催化剂上，ＣＨ４在６７３Ｋ就开始发生分解，并有Ｃ２Ｈ６、Ｃ２Ｈ４生成，１０２３Ｋ下，ＣＨ４几乎完全分解，单纯的ＣＯ２则很难在还原的催化剂上发生反应，在９７３Ｋ以上的高温下才会有少量Ｃ胜成ＣＯ．ＣＨＣＯ２的脉冲反应表明，当ＣＨ４在较低温度下开始分解时，ＣＯ２也会发生分解，并生成ＣＯ。脉冲反     

Rh—Mo—K／Al2O3催化剂的CO加氢合成低碳醇性能

本文研究了硫化态和还原态Ｒｈ－Ｍｏ－Ｋ／Ａｌ２Ｏ３催化剂上ＣＯ加氢合成低碳醇的反应性能，考察了不同铑负载量、钾助剂、合成气组成和反应条件（温度、压力和空速）对合成醇性能的影响及催化剂的反应稳定性。发现硫化样品较之还原态样品具有更好的合成醇选择性，催化剂中添加铑后，生成醇活性和选择性大幅度提高。选择合适的反应温度、提高反应压力和空速、适当增加合成气Ｈ２／ＣＯ的比例可以获得较好的合成醇反应性能。     

甲烷在Ni/TiO_2催化剂表面的活化

考察了Ｎｉ／ＴｉＯ２催化剂甲烷部分氧化和二氧化碳重整制合成气的反应活性,实验表明,以ＴｉＯ２为载体的镍系催化剂对于甲烷部分氧化制合成气反应具有较好的活性,尤其对Ｈ２的选择性较高,对二氧化碳重整制合成气反应具有较好的低温反应活性．采用脉冲－质谱在线分析等技术,在无气相氧条件下向Ｎｉ／ＴｉＯ２催化剂脉冲ＣＨ４,发现甲烷在催化剂表面的活化（转化）及其氧化产物的选择性与金属催化剂表面氧的浓度密切相关．ＣＨ４与Ｎｉ／ＴｉＯ２催化剂作用过程中存在明显的氢溢流和氧溢流现象,可能是这种溢流效应使得Ｎ／ＴｉＯ２催化剂具有良好的反应活性和抗积碳性能．     

激光促进乙醇氧化偶联反应

用ＸＲＤ、ＩＲ和脉冲ＣＯ２激光，研究了在固体Ｃｕ２（ＰＯ４）（ＯＨ）ｔ Ｐｂ３（ＰＯ４）２表面上激光促进乙醇氧化偶联的反应性能。实验结果表明：乙醇的定位化学吸附态决定着反应产物的选择性，甲基吸附态（〉Ｐ＝０…Ｈ－ＣＨ２ＣＨ２ＯＨ）反应生成１，４－丁二醇，而羟基吸附态（〉Ｐｂ…ＯＨＣＨ２ＣＨ３）则生成乙烯；固体表面构造基元的振动结构是影响激光能量利用率的主要因素，Ｃｕ２（ＰＯ４）（ＯＨ）表面Ｐ＝Ｏ键     

Co—Pt（Pd,Rh）／γ—Al2O3催化剂的脉冲吸附和程序升温研究

采用程序升温技术以及ＣＯ和Ｏ２的脉冲吸附方法，研究了Ｃｏ－Ｐｔ（Ｐｄ，Ｒｈ）／γ－Ａｌ２Ｏ３催化剂对Ｏ２和ＣＯ的吸附性能，及催化剂上Ｈ２，Ｏ２溢流的可能性，并探讨了ＣＯ的氧化机理。ＴＰＲ和ＴＰＯ－ＭＳ的结果表明，微量贵金属的存在不但促进了氧化态样品的还原，而且促进了还原态样品的氧化。     

氧化镍中非化学计量氧在乙烷氧化脱氢中的作用

以纯ＮｉＯ为模型催化剂考察了乙烷氧化脱氢（ＯＤＨＥ）性能，发现非化学计量氧的存在与反应的活性及选择性密切相关．ＴＧＡ研究结果表明，５００℃制备的样品具有ｘ≈６％的非化学计量氧．Ｈ２ＴＰＲ结果表明，非化学计量氧与晶格氧的可还原性明显不同；Ｏ２ＴＰＤＭＳ又把非化学计量氧区分为两个氧物种，Ｏ－２和Ｏ－（或Ｏ２－２）．脉冲试验结果表明，非化学计量氧对ＯＤＨＥ制乙烯是选择性反应的活性氧物种，晶格氧是完全氧化反应的活性氧物种．一旦催化剂中非化学计量氧耗尽并动用晶格氧时，催化剂便有Ｎｉ０生成，表现出自催化性能，使反应活性迅速提高，但产物均为ＣＯ２，ＣＯ，ＣＨ４等完全燃烧或裂解产物．为保持有较高的乙烯收率，反应处于稳态时Ｎｉ必须处于高价态．电导测定结果表明，优良的ＯＤＨＥ催化剂应有Ｐ型半导性．     

Ni/Al_2O_3催化剂上CH_4部分氧化制合成气机理的IR研究(英文)

在２．９％（ｗｔ）Ｎｉ／Ａｌ２Ｏ３催化剂上用ｉｎｓｉｔｕＦＴＩＲ研究了ＣＨ４部分氧化制合成气的反应机理。结果表明，催化剂表面的活性碳物种与化学吸附的Ｏ原子反应生成ＣＯ；ＣＨ４／Ｏ２（２：ｌ）混合气在催化剂表面吸附的ＩＲ谱图表明只有Ｈ２Ｏ和ＣＯ２存在，说明ＣＨ４和ＣＯ２的重整反应没有发生。因此，我们认为ＣＯ和Ｈ２是一级产物。     

担载Rh／Al2O3催化剂表面吸附态的加压原位红外光谱表征

应用加温加压气固多相催化原位红外光谱反应器,在Ｈ２／ＣＯ＝２：１（ｍｏｌ）、０．５￣５．０ＭＰａ和２０￣３００℃的接近ＣＯ＋Ｈ２工业反应条件下,考察了还原态和氧化态Ｒｈ／Ａｌ２Ｏ３催化剂表面ＣＯ吸附态,关联了吸附态与催化剂活性的关系。实验结果表明,还原态的Ｒｈ／Ａｌ２Ｏ３催化剂一氧化碳加氢生成烃类,其催化剂表面存在三种ＣＯ吸附态：线式Ｒｈ（ＣＯ）,孪生式Ｒｈ（ＣＯ）２和桥式Ｒｈ２ＣＯ。在常温常压下     

甲醇燃料车尾气净化催化剂的研究Ⅱ.负载钯催化剂对甲醇低温深度氧化性能的研究

利用色谱微反联用技术对负载钯催化剂上甲醇、甲醛的深度氧化进行了较全面的研究。结果表明：Ｐｄ／Ａｌ２Ｏ３催化剂对甲醇氧化具有很高的转化效率和一定的深度氧化活性。以（ＮＨ４）２ＰｄＣｌ４为浸渍液、还原气氛下焙烧所得的０．１％Ｐｄ／γＡｌ２Ｏ３性能最好，当进气Ｏ２／ＣＨ３ＯＨ比为６、并无ＣＯ存在时，其Ｔ５０、Ｔ９５分别为９０℃、２００℃，生成甲醛的最高转化率为１７％左右。另外，反应原料气组分如Ｏ２、ＣＯ等也将严重影响Ｐｄ／γＡｌ２Ｏ３对甲醇氧化的活性及选择性。     

Ni/Al2O3催化剂上甲烷部分氧化制合成气反应机理

用变应答／质谱在线检测技术研究了Ｎｉ／Ａｌ２Ｏ３催化剂上甲烷部分氧化制合成气的反应要理，研究结果指出，在常压９７３Ｋ条件下，Ｎｉ／Ａｌ２Ｏ３催化剂上甲烷部分氧化制合成气按直接氧化机理进行，Ｈ２和Ｃ烛甲烷部分氧化的一次产物，其主要反应可表示如下：１．ＣＨ４＋ｘＮｉ－ＮｉｘＣ＋２Ｈ２，２．Ｏ２＋２Ｎｉ－２ＮｉＯ，３．ＮｉｘＣ＋ＮｉＯ－ＣＯ＋（ｘ＋１）Ｎｉ。     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Acid hydrolysis of carboxymethylcellulose of low degree of substitution

Cotton cellulose was swollen in a sodium hydroxide solution and carboxymethylated by a two-bath method for different periods of time for each process. The kinetics of acid hydrolysis and the crystallinity of the swollen and carboxymethylated samples were measured. The proportion of broken bonds, rate constants for hydrolysis, and permeability of cellulose to hydrolyzing agents were calculated. The susceptibility of glycosidic linkages to acid hydrolysis was improved by carboxymethylation more than by swelling in alkali. The increased accessibility of carboxymethylcellulose to acid was regarded as a consequence of increased intra-and intercrystalline swelling and of the glycosidic bonds' weakness caused by the electron-attracting carboxymethyl group on the C-6 position.     

Estimation of Kinetic Parameters of Thermal Oxidation of Ilmenite

The aim of the presented work was the investigation of thermal oxidation of ilmenite in static air atmosphere. The investigations were carried out by use of a derivatograph (MOM, Hungary). The changes of crystallographic structure of investigated samples were identified by X-ray diffractometry on Philips PW-1710 diffractometer. In temperature above 500°C appears structure of hematite Fe₂O₃. On the basis of the thermogravimetric measurements, the contracting area and contracting volume models were found as the best fitting experimental data. This revised version was published online in August 2006 with corrections to the Cover Date.     

Mechanism of action of base-catalyzed oxygenation of phenol derivatives

Cyclopropyl derivative of 2,6-di-tert-butylphenol is synthesized as a probe to investigate the mechanism of base-catalyzed autooxidation of phenol derivatives. Our study indicates that one electron reduction of molecular oxygen from phenolate gives phenoxyl radical 3, a key intermediate of autooxidation. The coupling of phenoxyl radical and superoxide radical gives peroxylate anion 4 and produces the final epoxy alcohol adduct 6.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

化学计量中不确定度评定研究进展

测量不确定度是表征合理地赋予被测量之值的分散性的参数。本文针对化学计量不确定度评定基础模型仅适用于线性模型、概率分布为正态分布或缩放位移t分布等局限,介绍了近年来不确定度评定的研究热点:蒙特卡罗方法(Monte Carlo Method,MCM),不确定度评定的来源、评定概念、评估方法及其发展过程,扩大了测量不确定度评定与表示的适用范围。     

微量钙的测定方法研究进展

介绍了1995-2006年期间测定微量和痕量钙的方法,如电感耦合等离子体-原子发射光谱法、原子吸收光谱法以及离子色谱法等的工作原理和特点,并说明了其测定微量钙的应用领域。并对微量钙的测定技术进行了展望(引用文献55篇)。     

Stages of thermal decomposition of sodium oxo-salts of sulphur

Thermal behaviour of sodium oxo-salts of sulphur: Na₂SO₄, Na₂S₂O₇, Na₂S₂O₆, Na₂SO₃, Na₂S₂O₅, Na₂S₂O₄, Na₂S₂O₃, Na₂S₃O₆ and of sulphides Na₂S and Na₂S₂ was studied on heating up to 1000°C. The experiments were performed with anhydrous compounds obtained from commercial products by recrystallisation and dehydration. The stage mechanisms of decomposition of anionic sub-lattices of the salts have been proposed basing on the Górski’s morphological classification of simple species. The thermal stability and the stage decomposition mechanisms were correlated with the structure and the potential chemical properties of the salt anions. The thermal decomposition processes were studied by means of thermal analysis, and the decomposition products were identified by means of X-ray phase analysis.