吸热型碳氢燃料在银、镧改性混合分子筛上的裂解研究

为进一步提高吸热型碳氢燃料的吸热能效，考察了吸热型碳氢燃料NNJ－150在USHY和HZSM－5混合分子筛以及银、镧改性混合分子筛催化剂上的催化裂解。结果表明，在Ag-LaUSY Ag-LaZSM-5(75:25)混合分子筛催化NNJ－150裂解反应中，低碳烯烃选择性较高，催化剂寿命较长。采用此催化剂，能较好满足吸热型碳氢燃料裂解的需要。     

Theory of helicenic hydrocarbons. Part 1: Invariants and symmetry

Helicenes form a subclass of polyhexes and correspond to hydrocarbons of considerable chemical interest. This paper is the first part of a general graph-theoretical treatment of helicenes. The invariants are studied: the relations between them, their possible values, and their upper and lower bounds in helicenes. Extremal helicenes and circular helicenes are useful definitions of subclasses of the systems under consideration. Finally an account of symmetry of helicenes is given.On leave from: Department of Mathematics, Xinjiang University, Wulumuqi Xinjiang 830046, People's Republic of China.     

Application of Task-specific Ionic Liquids for Intensified Separations

Summary. Ionic liquids offer tremendous opportunities to intensify reactions and separations in process technologies by tuning their physical and chemical properties. Several ionic liquids are suitable for the separation of aromatic and aliphatic hydrocarbons. CO₂ absorption behavior was influenced by the functionalized chains appended to the room temperature ionic liquid (RTIL) cation. Ionic liquids seem able to combine the chemical features of amine solutions with the characteristic advantages of the physical solvents used for CO₂ absorption.     

改性Y分子筛的酸碱性能及吸附性能的研究

吡啶、吡咯、苯、甲苯、乙苯作为探针分子，在Li＋, Na＋, K＋, Cs＋改性的Y型分子筛上进行吸附，用TPD及IR方法系统地研究了不同碱金属离子改性的Y型分子筛的酸碱性能和吸附性能的变化. 结果表明，按Li、Na、K、Cs的顺序, 随着碱金属离子半径的增大, 其L酸酸强度依次减弱，L碱的强度逐渐增强.由于改性Y型分子筛所含碱金属离子的不同，其对芳烃的吸附的强弱及吸附量的大小亦不同.随着骨架外的阳离子的半径逐渐增大，碱的强度逐渐增强，与芳烃的作用愈强烈，导致TPD脱附峰温增高及芳烃和侧链上的C－H伸缩振动谱带向低波数位移愈多.由于位阻的原因，对含同一种碱金属离子的分子筛来说，随着芳烃侧链C数的增加，芳烃的吸附量逐渐减小.     

吸热型碳氢燃料在银、镧改性ZSM-5分子筛上的裂解研究

为提高吸热型碳氢燃料的吸热能效，对HZSM－5分子筛进行了La^3 、Ag^ 离子交换改性，考察了吸热型碳氢燃料NNJ－150在HZSM－5及改性ZSM－5分子筛催化剂上的裂解情况。结果表明，La^3 、Ag^ 离子交换改性催化剂提高了NNJ－150的裂解气中低碳烯烃的选择性（500℃,81.63%)，并且改性催化剂和未改性催化剂的活性在35min内均未随进样时间下降，转化率也未降低（500℃,HZSM-5,64.62%;LaZSM-5,65.71%；AgZSM-5,68.75%)。实验结果表明，双金属离子改性可为今后研究的方向。     

Computing the Kekulé structure count for alternant hydrocarbons

A fast computer algorithm brings computation of the permanents of sparse matrices, specifically, molecular adjacency matrices. Examples and results are presented, along with a discussion of the relationship of the permanent to the Kekulé structure count. A simple method is presented for determining the Kekulé structure count of alternant hydrocarbons. For these hydrocarbons, the square of the Kekulé structure count is equal to the permanent of the adjacency matrix. In addition, for alternant structures the adjacency matrix for N atoms can be written in such a way that only an N/2 × N/2 matrix need be evaluated. The Kekulé structure count correlates with topological indices. The inclusion of the number of cycles improves the fit. When comparing with previous results, the variance decreases 74%. The calculated standard heat of formation correlates with the logarithm of the Kekulé structure count. This heat increments 349 kJ/mol each time the Kekulé structure count increases by one order of magnitude. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002     

Intracellular fate of hydrocarbons

In previous work, purification procedures and zymogram analysis conducted with supernatants of crude extracts from aerobic mycelium of the YR-1 strain of Mucor circinelloides isolated from petroleum-contaminated soils indicated the existence of only one soluble alcohol oxidase (sAO) activity. In the present work enzymatic activity of alcohol oxidase (AO) was also detected in the mixed membrane fraction (MMF) of a high-speed centrifugation procedure after drastic ballistic cellular homogenization to break the mycelium from strain YR-1. When mycelial cells were gently broken by freezing the mycelium with liquid nitrogen, smashing in a mortar, and submitting the samples to an isopycnic sucrose gradients (10–60% sucrose), AO activity was detected in particular and discrete fractions of the gradient, showing specific density values quite different from the density of peroxisomes. The results suggest that there could be a different intracellular pattern of distribution of the microsomal fraction in aerobically grown mycelium depending on the carbon source used in the culture media, including alcohols and hydrocarbons, but not in glucose. In working with particulate fractions, we found two AO activities: a new membrane alcohol oxidase (mAO) activity and the sAO. Both activities appear to be located in the inner of the cells in specific compartments different from the peroxisomes, so mAO could be in the membrane of these compartments and sAO in the lumen of the vesicles. We also assayed other enzymatic activities involved in hydrocarbon biodegradation to establish its intracellular location and other enzymatic activities such as peroxidase to use them as intracellular markers of different organelles. In the case of monooxygenase, the first enzymatic step in the hydrocarbon biodegradation pathway, its location was in the same fractions where AOs were located, suggesting the existance of a specific organelle that contains the enzymatic activities involved in hydrocarbon biodegradation.     

高中有机化学教材“烃类化合物”的国际比较研究

基于闫春更等建立的二维度四指标教材难度微观评价模型，重点对中国、美国、新加坡、澳大利亚、日本、英国的高中化学教材中"烃类化合物"内容的整合广度、表征深度进行测评和比较。研究发现6国教材内容的整合广度整体上差异不大，但其表征深度差异明显；美国教材注重学生认识物质的思路和方法的渗透，日本教材注重基本知识与技能的掌握，中国教材将概念诠释与样例分析相融合；英国、新加坡、美国教材注重情境推理或比较等信息处理策略的运用，对学习者学习的引导性较强。     

Kekulé structure counts for some classes of all-benzenoid and all-coronoid hydrocarbons

Summary A general formula for the Kekulé structure count (K) is deduced for the class of catacondensed all-benzenoids with unbranched backbones. The formula is extended to thin pericondensed all-benzenoids, where allowance is made for pyrene units. In this treatment the fragmentation matrices are employed. A generalization of these matrices is furnished. Next some generalK formulas for classes of catacondensed and thin pericondensed all-coronoids are deduced. Again the fragmentation matrices are employed, but the problem is also studied in terms of certain polynomials.Dedicated to the memory of Professor Oskar E. Polansky, who died in January 1989. He was the one who coined the term all-benzenoid.     

用近红外光谱仪快速测定调和汽油中芳烃、烯烃的含量

介绍了带有CCD检测器的近红光普仪在调和汽油分析中的应用，并与标准测定方法测定的数据对比，验证了近红外光谱法测定汽油性质的可靠性，同时表明该方法具有分析速度快，重现性好等特点。