新型高效甲醇水相低温制氢催化剂

<正>新能源的开发和利用能有效缓解能源危机和环境问题。氢能单位质量燃烧热值高,生成的尾气清洁无污染,是重要的新能源材料。氢燃料电池可以将氢能高效地转化为电能,然而,氢气的存储和输运一直是阻碍氢能大规模应用的瓶颈[1]。将氢气储存于液体燃料再通过催化反应原位释放氢气并供给燃料电池使用是一种行之有效的间接储氢策略[2,3]。甲醇作为一种候选液态储氢介质具有单位体积储氢量高、活化温度低、副产物少以     

纳米限域的储氢材料

氢能作为洁净、理想的二次能源,已受到世界各国的广泛关注。然而,氢的储存技术仍然是制约氢能商业化应用的关键技术。利用储氢材料进行储氢被认为是一种安全、高效的固态储氢方式。因此,开发新型高容量的储氢材料与储氢技术成为氢能领域研究的热点之一。纳米限域是将材料填充到纳米孔道里,利用材料和纳米孔道的相互作用促进反应的进行,为化学反应提供一个独特的微环境。近年来,纳米限域逐渐发展成为改善储氢材料热力学和动力学的新方法。本文综述了纳米限域的储氢材料的研究进展,从纳米限域的储氢材料制备、储氢性能、反应机理和存在的问题等方面进行讨论,并指出了纳米限域储氢材料的发展趋势。     

轻金属配位氢化物储氢体系

实现氢能有效利用的关键技术是开发安全、经济、高效的氢能储运体系。在目前所有的储氢技术中,固态材料化学储氢因其储氢密度大、可循环使用、安全方便储运等优势成为人们关注的焦点;配位氢化物储氢材料是现有储氢材料中体积和质量储氢密度最高的储氢材料。其中,具有高储氢密度、储氢性能优良的轻金属配位氢化物储氢材料是配位氢化物储氢领域研究的重点,目前已经取得了大量成果。本文论述了主要轻金属配位氢化物储氢体系的研究进展,包括硼氢化物储氢体系、铝氢化物储氢体系、氨基化物储氢体系等,阐述和总结了其热解反应机理、动力学性能、晶体结构、最新研究现状,最后对该领域的研究方向进行了总结和展望,指出二元或多元复合储氢体系、高效纳米粒子催化剂和储氢反应环境的综合协同效应将会成为储氢领域未来的研究趋势和重要研究方向。     

储氢研究进展

氢能是21世纪主要的新能源之一。作为一种新型的清洁能源，氢的廉价制取、安全高效储存与输送及规模应用是当今研究的重点课题，而氢的储存是氢能应用的关键。储氢材料能可逆地大量吸放氢，在氢的储存与输送过程中是一种重要载体。本文综述了目前所采用或正在研究的主要储氢材料与技术，如高压气态储氢、低温液态储氢、金属氢化物储氢、化学氢化物储氢、吸附储氢、金属有机骨架储氢等，比较了各种储氢的优缺点，并指出其相关发展趋势。     

Pt/α-MoC催化剂用于低温甲醇水相重整制氢

<正>氢燃料电池是最具潜力的新一代能量提供系统。但氢气的存储和输运一直是阻碍氢能大规模应用的瓶颈~1,将氢气储存于液体燃料再通过催化反应原位释放氢气供应燃料电池使用是一种行之有效的间接储氢途径~2。甲醇具有单位体积储氢量高、活化温度低、副产物少以及价廉易得等诸多优点,是理想的液体储氢平台分子。甲醇和水气相重整过程的研究已经非常广泛而深入。相比气相重整,在水相直接进行重整能够移除液体汽化     

基于绿色氢科学理念构筑从低碳制氢到高效储氢的氢能体系

本文从低碳制氢和高效储氢的角度思考及探讨氢能体系绿色化发展过程中的关键科学问题.提出＂绿色氢科学＂理念与＂低碳制氢,高效储氢＂技术发展路线图,以期通过相关科学问题的认识,来构建具有高度原子经济性及可持续性的绿色氢能体系.     

储氢研究进展

氢能是21世纪主要的新能源之一。作为一种新型的清洁能源,氢的廉价制取、安全高效储存与输送及规模应用是当今研究的重点课题,而氢的储存是氢能应用的关键。储氢材料能可逆地大量吸放氢,在氢的储存与输送过程中是一种重要载体。本文综述了目前所采用或正在研究的主要储氢材料与技术,如高压气态储氢、低温液态储氢、金属氢化物储氢、化学氢化物储氢、吸附储氢、金属有机骨架储氢等,比较了各种储氢的优缺点,并指出其相关发展趋势。     

储氢研究进展

氢能是21世纪主要的新能源之一.作为一种新型的清洁能源,氢的廉价制取、安全高效储存与输送及规模应用是当今研究的重点课题,而氢的储存是氢能应用的关键.储氢材料能可逆地大量吸放氢,在氢的储存与输送过程中是一种重要载体.本文综述了目前所采用或正在研究的主要储氢材料与技术,如高压气态储氢、低温液态储氢、金属氢化物储氢、化学氢化物储氢、吸附储氢、金属有机骨架储氢等,比较了各种储氢的优缺点,并指出其相关发展趋势.     

金属-碳基储氢材料计算与实验研究

氢能以其资源丰富和环境友好性成为未来最具发展潜力的能源。储氢技术是氢能应用中的关键问题。随着计算材料学的发展,利用密度泛函和量子机制第一性原理研究已知材料储氢性能和寻找潜在的新型优良储氢载体已成为当前研究储氢材料的有效方法。本文综述了近年来金属-碳基储氢材料中的金属修饰碳纳米管、C₆₀材料和过渡金属-乙烯复合物的理论计算与实验研究进展,并对该领域未来的研究工作进行了展望。     

储氢材料的研究进展

日益严峻的能源危机和环境污染,使得发展清洁的可再生能源成为世界各国的重要课题。氢能源以其可再生性和良好的环保效应成为未来最具发展潜力的能源载体,氢能被公认为人类未来的理想能源,而氢的储存是发展氢能技术的难点之一。介绍了各类材料的储氢功能特点和近年来几类主要储氢材料的研究进展,并指出了储氢材料的发展方向。     

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。     

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.     

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.     

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^-。     

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.     

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.     

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.