Solvent intercalation in cobalt dimethylglyoximato complexes: A miniature host-guest system

When crystallized from appropriate solvents, the complex aqua-bis(dimethylglyoximato)nitrocobalt (III) may incorporate solvent molecules, thus forming a variety of mixed crystals. In the resulting host-guest crystals, the space groupP2_l/m and the packing motif of the pure host compound are retained. Lattice constantsa andb remain essentially unaltered upon intercalation, whereasc and the monoclinic angle depend largely on the clathrated guest. Space filling and intermolecular contacts are discussed.Dedicated to Professor Peter Paetzold at the occasion of his 60th birthday. A preliminary account of this work has been given at the Spring Meeting of the British Crystallographic Association, Newcastle upon Tyne, 1994.     

BEHAVIOR OF SUPPORTED NANO-COPPER CATALYST IN CO OXIDATION

IntroductionNanomaterialisanewkindofmaterialwithparticlesizebetWeenIurnand100urn.Becauseofthesmallparticlesizeandthelargespecificsufficearea,nanomaterialpossessesmanyparticularproperties,suchashighersufficeenergyandhighersurfaceactivity.t.[l]Thehigheracti…     

A new method for predicting conduction anesthesia

A new method for predicting conduction anesthesia has been suggested. The method is based on calculation of theP matrix probabilities of interatomic contacts for each molecule of the compounds considered. TheP matrix enables one to evaluate the main tendencies of atoms and atomic groups to interact in biochemical sorption on the nerve fiber surface. The minimum effective concentrations calculated for 25 compounds are in good agreement with the experimental data. The correlation coefficient between the experimental and calculated values is 0.98 when the standard deviation is 0.1 mmol L⁻¹. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1781–1784, October, 1997.     

配位-沉淀法制备Ni(OH)2和NiO超微粉

本工作采用配位 -沉淀法成功的制备了薄片形氢氧化镍和氧化镍超微粉末 ,通过 XRD、TG-DTA、IR及 TEM等实验手段对超微粉的组成结构进行分析表征。     

BaCe1—xRExO3—0.5x的溶胶—凝胶法合成及离子导电性

用溶胶－凝胶法合成了系列钙钛矿结构的ＢａＣｅ１－ｘＲＥｘＯ３－０．５ｘ（ＲＥ＝Ｌａ，Ｎｄ，Ｓｍ，Ｅｕ，Ｇｄ，Ｄｙ，Ｈｏ，Ｅｒ和Ｙ）复合氧化物，通过ＸＲＤ和热分析对样品结构及生成过程进行了研究．测定了不同温度下样品的交流阻抗谱，讨论了稀土离子掺杂对ＢａＣｅＯ３电性质的影响．溶胶－凝胶法比固相反应法合成温度降低了６００～８００℃，稀土掺杂使ＢａＣｅＯ３离子导电率提高了１０～４０倍．     

非均相羰基氧化合成碳酸二苯酯反应液组分的分析

通过色质联用仪对非均相催化一步合成碳酸二苯酯(DPC)过程中的反应液的主要产物及副产物进行了定性分析，其结果发现该反应的主要副产物为苯氧基丙酸和4-苯氧基苯酚以及四丁基铵盐；用气相色谱外标法对反应液中的DPC进行了定量分析，并通过回归法得到了定量分析：DPC的计算方程式，实验证明该方程在DPC的浓度小于10％范围内比较可靠。     

Promoting effect of sol-gel method and pre-treatment on the activity of SnO2/Al2O3 catalyst for NO reduction by propene

SnO₂/Al₂O₃ catalyst prepared by sol-gel method showed higher activity than those prepared by impregnation method, and their activity was significantly improved by pre-treatment in the reaction gas. The increased activity is closely related to the agglomeration of SnO₂ species and the re-exposure of Al₂O₃, which was previously covered by dispersed SnO₂ species. This revised version was published online in June 2006 with corrections to the Cover Date.     

水热合成MoO3纳米带的生长机理研究

以离子交换法制备的氧化钼溶胶为前驱体，在水热条件下制备了单晶MoO₃纳米带，对样品进行了XRD、SEM和TEM分析。通过考察水热反应温度和时间对产物结构和形貌的影响，结合材料热力学和动力学理论，探讨了MoO₃纳米带在水热条件下的生长机理。离子交换法制备的溶胶在水热条件下首先转变为热力学亚稳相h-MoO₃六角柱，随着温度的升高和时间的延长，h-MoO₃按照溶解-重结晶过程转变为稳定相α-MoO₃纳米带。     

全氟烷基磺酸酯C-O键断裂的同面SN2反应

用密度泛函理论研究了CF3SO3CF2CF3 F^-的碳氧键断裂反应的机理。首先，用DFT方法优化了反应物、中间体、过渡态、产物的平衡构型，分析了碳氧键断裂反应的势能面变化，发现在SN2反应机理中，除了S-O断裂SN2反应外，引起C-O键断裂的同面进攻也是一个可能的反应途径。理论计算表明，最终反应的产物是受热力学控制的，S-O键的断裂绝对地优于C-O的断裂。因此，C-O断裂的同面机理虽然是可能的，但却难以被实验观察到，本文还讨论了端基-CF3在同面SN2反应中的邻位效应，以及基组对这个效应的影响。     

溶胶凝胶法制氧化铝负载铜基超细粒子催化剂的研究

采用溶胶凝胶法制氧化铝负载铜基超细粒子催化剂的制备了氧化铝负载的铜基超细粒子催化剂，用ＴＧ－ＤＴＡ，ＸＲＤ，ＢＥＴ以及ＴＥＭ等技术手段，对催化剂的物相结构，表面孔结构，粒子形貌以及催化性能等进行了研究。结果表明，利用溶胶凝胶法，可以直接帛备出高比表面积，低堆积密度的纤维状纳米级负载型Ｃｕ／Ａｌ２Ｏ３超细粒子；活性组分以远低于纳米级的微晶粒子簇状态，均匀地分散在纳米级氧化铝载体表面上，而且在低于５０