甲基化的β-环糊精与十六烷基三甲基溴化胺的相互作用

环糊精与表面活性剂的相互作用已有许多研究,但多局限于β－环糊精（β－CD）,而修饰的β－环糊精与表面活性剂的相互作用研究较少[1－3]．分子内扭转电荷转移（TICT）激发态对介质极性高度敏感性,已成功地用于探针环糊精与表面活性剂的相互作用[4]．研究表明,β－CD能够诱     

海水中某些稀有金属的分离预富集和ICP光谱法测定研究

本提出了以聚二硫代氨基甲酸盐螯合树脂分离预富集－ＩＣＰ－ＡＥＳ测定海水中稀有金属Ｕ，Ｎｂ，Ｔａ，Ｚｒ和Ｈｆ的新方法，对上述元素与螯合树脂在不同ＰＨ下的静态交换行为进行了研究。考察一溶液酸度，流速及基体元素对分离富集效果的影响，比较了吸附在树脂上的待测元素的解脱方法，在优化的实验条件下，方法的相对检出限为０．０２－０．１７ｎｇ／ｍＬ，应用于海水试样分析时，其回收率在８１％－９４％之间。     

Syntheses，Structures and Spectroscopic Properties of Mo（W）－Cu－S－Cluster Compounds with Dialkyldithiocarbamate Ligands

Ｓｙｎｔｈｅｓｅｓ，ＳｔｒｕｃｔｕｒｅｓａｎｄＳｐｅｃｔｒｏｓｃｏｐｉｃＰｒｏｐｅｒｔｉｅｓｏｆＭｏ（Ｗ）－Ｃｕ－Ｓ－ＣｌｕｓｔｅｒＣｏｍｐｏｕｎｄｓｗｉｔｈＤｉａｌｋｙｌｄｉｔｈｉｏｃａｒｂａｍａｔｅＬｉｇａｎｄｓＣａｏＲｏｎｇ；ＬｅｉＸｉｎ－Ｊｉ...     

Synthesis and crystal structure of [V_2(μ-S_2)_2(S_2CNEt_2)_4]·2CH_3Cl

[V_2(μ-S_2)_2(S_2CNEt_2)_4].2CH_3Cl was synthesized by the reaction of NaS_2CNEt_2,Li_2S andVOCl_3 at room temperature.Crystal data:M=1061.3,space group Pbca,with the orthorhombicparameters:a=20.123(3),b=20.485(4),c=10.911(3),V=4497.7,Z=4,D_c=1.57g/cm~3,Mo Kσradiation(λ=0.71069()?),μ=13.2 cm~(-1),F(000)=2168.Final R=0.041 and R_w=0.047 for 2288 ob-served reflections with I>3σ(1).The coordination sphere of each V atom in title compound is a dis-torted tetragonal prism composed of two bidentate dithiocarbamate and two S_(2~((2-)) ligands.The V—Vdistance is 2.890 while the V—S distances fall in the range of 2.422—2.505.     

Studies on the substrate specificity of Escherichia coli galactokinase

In vitro glycorandomization (IVG) technology is dependent upon the ability to rapidly synthesize sugar phosphates. Compared with chemical synthesis, enzymatic (kinase) routes to sugar phosphates would be attractive for this application. This work focuses upon the development of a high-throughput colorimetric galactokinase (GalK) assay and its application toward probing the substrate specificity and kinetic parameters of Escherichia coli GalK. The demonstrated dinitrosalicylic assay should also be generally applicable to a variety of sugar-processing enzymes. [reaction: see text]     

有害杂草的微量元素分析

紫茎泽兰和水葫芦均属有害杂草，大规模防治的有效方法还未找到，本文分析研究了采自昆明郊区的紫茎泽兰和滇池水域的水葫芦中微量元素的含量，为进一步开发利用这两种杂草提供科学依据。     

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。     

N-Heterocyclic Olefins as Electron Donors in Combination with Triarylborane Acceptors: Synthesis,Optical and Electronic Properties of D–π–A Compounds

N-heterocyclic olefins (NHOs), relatives of N-heterocyclic carbenes (NHCs), exhibit high nucleophilicity and soft Lewis basic character. To investigate their π-electron donating ability, NHOs were attached to triarylborane π-acceptors (A) giving donor (D)–π–A compounds 1 – 3 . In addition, an enamine π-donor analogue ( 4 ) was synthesized for comparison. UV–visible absorption studies show a larger red shift for the NHO-containing boranes than for the enamine analogue, a relative of cyclic (alkyl)(amino) carbenes (CAACs). Solvent-dependent emission studies indicate that 1 – 4 have moderate intramolecular charge-transfer (ICT) behavior. Electrochemical investigations reveal that the NHO-containing boranes have extremely low reversible oxidation potentials (e.g., for 3 , =−0.40 V vs. ferrocene/ferrocenium, Fc/Fc⁺, in THF). Time-dependent (TD) DFT calculations show that the HOMOs of 1 – 3 are much more destabilized than that of the enamine-containing 4 , which confirms the stronger donating ability of NHOs.     

超临界流体技术在制备药物输送系统中的应用

超临界流体技术以其特有的优点成为引人注目的制备药物细微粒子及控制释放的药物输送系统的方法。本文介绍了超临界流体沉淀技术的概念、进展及相关的应用。     

碳化硼纳米线的制备和结构

以碳纳米管为模板，通过加热碳纳米管与硼粉的混合物，获得了笔直的硼碳纳米线.对纳米线的结构和成分进行研究，结果表明纳米线主要为B4C纳米线.在部分B4C纳米线的端部存在Ni颗粒，这些端部具有Ni颗粒的纳米线构成了纳米磁针.讨论了B4C纳米线的生长机制，B4C纳米线的生长主要为硼原子在碳纳米管中扩散并发生化学反应，使得碳纳米管晶格结构发生重组，形成B4C纳米线.反应后，硼原子部分取代了碳纳米管中碳原子，修补了碳纳米管中的晶格缺陷，获得了形态笔直的B4C纳米线.