Synthesis of Diethyl Oxalate by a Coupling-Regeneration Reaction of Carbon Monoxide

This article describes a process for the synthesis of diethyl oxalate by a coupling reaction of carbon monoxide, catalyzed by palladium in the presence of ethyl nitrite. The kinetics and mechanism of the coupling and regeneration reaction are also discussed. This paper presents the results of a scale-up test of the catalyst and the process based on an a priori computer simulation.     

用L-脯氨酸衍生物作为手性流动相添加剂拆分对映异构体

用自制的N-十二酰基-L-脯氨酸和N-十二酰基-L-脯氨酸-3，5-二甲基苯胺两种L-脯氨酸衍生物作手性流动相添加剂，在氨丙基硅烷化硅胶柱上，用正己烷／异丙醇作流动相，对多种手性化合物进行了高效液相色谱拆分。实验结果表明：用N-十二酰基-L-脯氨酸作添加剂拆分的12种手性化合物，有8种手性化合物能得到拆分，具有较好的手性选择性。虽然用N-十二酰基-L-脯氨酸-3，5-二甲基苯胺作添加剂，手性选择性也较好，但由于含有苯环，紫外吸收增强，基线波动严重。     

Investigation of Aconitine-type Alkaloids from Processed Tuber of Aconitum carmiechaeli by HPLC-ESI-MS/MS~n

Introduction Aconitine-type alkaloids isolated from the roots of Aconitum carmiechaeli show a potential toxicity and a broad spectrum of bioactivity[1-4].On the basis of the C8-substituent of C19-diterpenoid skeleton,aconitine-type alkaloids can be divided into diester-diterpenoid alkaloids(DDAs),monoester-diterpenoid alkaloids(MDAs),and lipo-alkaloids(Fig.1).     

Adaptation of Cu/ZnO/Al_2O_3 to Temperature Change in Methanol Synthesis from CO_2 Hydrogenation

The induction behavior in CO2 hydrogenation was studied by varying the reaction temperature to investigate the adaptation of the Cu/ZnO/Al2O3 catalyst to the temperature change. The results indicated that a used catalyst had a tendency to keep the last running state in new reaction conditions for MeOH formation, and that this tendency was related to the difference in Cu/Cun+ ratio caused by CO2 and CO produced at different reaction temperatures. However, the reverse water-gas shift reaction (RWGS) induced at four temperatures was completely different from that of methanol synthesis. It implied that the two so-called competitive reactions in CO2+H2, RWGS and methanol synthesis, have different active centers.     

Study on the Binding Effect between Cordycepin and Calf Thymus DNA by Circular Dichroism

DNA works as hereditary material and plays vital role in life science. The study of the binding of small molecules complex to DNA has been the focus of intense investigation, owning to their stereo and sequence specific interaction with the double helix1-…     

Preparation and Characterization of Microencapsulated Hexadecane Used for Thermal Energy Storage

Polyurea microcapsules about 2.5μm in diameter containing phase change material for thermal energy storage application were synthesized and characterized by interfacial polycondensation method with toluene-2,4-diisocyanate and ethylenediamine as monomers in an emulsion system. Hexadecane was used as a phase change material and OP, which is nonionic surfactant, and used as an emulsifier. The chemical structure and thermal behavior of the microcapsules were investigated by FTIR and thermal analysis respectively. The results show encapsulated hexadecane has a good potential as a solar energy storage material.     

Adsorption of Carbon Dioxide on Activated Carbon

The adsorption of CO2 on a raw activated carbon A and three modified activated carbon samples B, C, and D at temperatures ranging from 303 to 333 K and the thermodynamics of adsorption have been investigated using a vacuum adsorption apparatus in order to obtain more information about the effect of CO2 on removal of organic sulfur-containing compounds in industrial gases. The active ingredients impregnated in the carbon samples show significant influence on the adsorption for CO2 and its volumes adsorbed on modified carbon samples B, C, and D are all larger than that on the raw carbon sample A. On the other hand, the physical parameters such as surface area, pore volume, and micropore volume of carbon samples show no influence on the adsorbed amount of CO2. The Dubinin-Radushkevich (D-R) equation was the best model for fitting the adsorption data on carbon samples A and B, while the Preundlich equation was the best fit for the adsorption on carbon samples C and D. The isosteric heats of adsorption on carbon samples A, B, C, and D derived from the adsorption isotherms using the Clapeyron equation decreased slightly increasing surface loading. The heat of adsorption lay between 10.5 and 28.4 kJ/mol, with the carbon sample D having the highest value at all surface coverages that were studied. The observed entropy change associated with the adsorption for the carbon samples A, B, and C (above the surface coverage of 7 ml/g) was lower than the theoretical value for mobile adsorption. However, it was higher than the theoretical value for mobile adsorption but lower than the theoretical value for localized adsorption for carbon sample D.     

Λ-、△-[Rh（bpy）2chrysi]^3＋对含C：T错配的DNA序列识别作用的分子模拟研究

通过分子模拟方法研究了手性金属配合物[Rh（bpy）2Chrysi]^3＋（bpy=2，2’-bipyridineChrysi=5，6-chrysenequinonediimine）对包含C：T错配碱基对的B-DNA序列的识别作用．结合类似的针对含G：A错配的和正常的B-DNA序列的识别作用研究，发现配合物I-Rh（bpy）zChrysi]^3＋可以对错配B-DNA序列进行序列特异性的识别．能量对比计算结果表明，该经典插入识别作用倾向于在错配碱基对附近进行，其中△-[Rh（bpy）2chrysi]^3＋比其手性异构体更占优势．这同Barton教授工作组的实验结果是一致的．另外插入作用倾向于在错配序列中的正常双碱基对C3A4／G3T4（错配碱基对附近）中从小沟进行．与该配合物对含G：A错配的和正常的B-DNA序列的识别作用不同的是，对包含C：T错配碱基对的B-DNA序列的识别作用倾向于从小沟进行．这一点可能源于C：T碱基对结构的不同．     

洛克希德·马丁公司完成 GPSIII卫星导航有效载荷研制

负责开发美国空军“下一代全球定位系统（GPSIII）”的洛克希德·马丁公司已经完成了GPSIII项目的“探路者”，即GPSIII非飞行卫星试验平台（GNST）的主要集成和测试。这一具有里程碑意义的事件使GPSIII团队有望在2014年交付首颗卫星。     

黑龙江省通信管理局与工业和信息化部电信研究院签署战略合作框架协议

黑龙江省通信管理局与工业和信息化部电信研究院于10月18日在北京签署战略合作框架协议。此次签署的战略合作框架协议涉及的合作内容包括政策研究与咨询，设备认证、应急通信、电信计费、网络与信息安全、