Phosphate Diester Hydrolysis by Dinuclear Tb(III) Complexes with BDBPH in Second-order Dependence

In the past decade, many lanthanide metal complexes with polyazamacrocycle, Schiff base, and glycol ligands have been shown to enhance the rate of DNA-phosphate hydrolysis by seven orders of magnitude1-3. This efficiency results from the conjunction of hi…     

CrOx/SiO2催化剂上丙烷在CO2气氛中脱氢反应的研究

采用ＸＲＤ、ＵＶ－ｖｉｓ　 ＤＲＳ、ＥＳＲ和微分吸附量热等技术,考察了铬担载量分别为２．５、５和 １０ｗｔ％的 ＣｒＯｘ／ＳｉＯ２催化剂的结构、表面性质和氧化还原性能。结果表明,催化剂表面上存在多种Ｃｒ的氧化态和聚集形式。随着Ｃｒ担载量从２．５ｗｔ％到１０ｗｔ％的逐渐增大,催化剂表面占主导地位的Ｃｒ物种由ＣｒＯ３单体转为多聚ＣｒＯ３和Ｃｒ２Ｏ３晶相。在 ＣＯ２气氛中催化剂对丙烷转化率和丙烯选择性的大小顺序为 ２． ５ｗｔ％ ＣｒＯｘ／ＳｉＯ２ ＞５ｗｔ％ ＣｒＯｘ／ＳｉＯ２＞１０ｗｔ％ ＣｒＯｘ／ＳｉＯ２,反应过程中的原位 ＥＳＲ和 ＵＶ－ｖｉｓＤＲＳ测定结果表明,催化剂表面的反应活性中心为Ｃｒ５＋, Ｃｒ５＋可由催化剂预处理过程中 Ｃｒ３＋的氧化及丙烷反应过程中 ＣｒＯ３单体的还原产生,在反应中 ＣＯ２可使Ｃｒ３＋重新氧化为Ｃｒ５＋。     

溶液燃烧法制备LiCoO_2及其同时催化去除碳烟和NO_x性能研究

采用溶液燃烧法和盐助溶液燃烧法制备铜铁矿结构(ABO2)的钴酸锂(Li Co O2)系列催化剂,通过XRD、BET、ICP、XPS、H2-TPR、程序升温反应等手段对其进行了结构表征与性能评价.研究了溶液燃烧法中燃料尿素以及助剂无机盐Na Cl的用量对所制备的催化剂性能影响.实验结果表明,在尿素过量100%时所制备的催化剂结晶程度及催化氧化性能较好,起燃温度达到270℃,N2的转化率达到36.9%.适量助剂Na Cl的引入显著地提高了催化剂比表面积,增加了催化剂表面活性物种,增强了催化剂的氧化还原能力,进而提升催化剂的活性.其中50%质量分数的Na Cl添加量制备的催化剂具有最低的碳烟起燃温度(246℃),但添加Na Cl对NOx的转化率影响不大.     

连接环、末端碱基及一价阳离子对G-四链体结构的影响

研究了G-四链体中的连接环(Loop)、末端碱基和一价阳离子对其结构的影响,发现在K+溶液中Loop短的序列易形成平行结构,无末端碱基时容易形成多聚体,而反平行或混合平行/反平行的G-四链体则难以形成多聚体;一价阳离子K+,NH+4和Na+促进形成平行结构及多聚体的能力依次减弱.在平行G-四链体的3’或5’端增加非G碱基,或改变阳离子使其形成非平行结构,均可抑制多聚体的形成.Loop长度影响G-四链体的热稳定性,Loop短的序列可形成很稳定的分子内结构;无末端碱基的G-四链体多聚体的稳定性低于单个G-四链体,且多聚体随着温度升高而变小.结果表明,在K+溶液中,无末端碱基的平行G-四链体序列首先形成分子内结构,然后通过π-π堆积形成多聚体;末端碱基及反平行或混合平行/反平行G-四链体中的Loop可阻碍末端堆积作用,抑制多聚体的形成.本研究为G-四链体的结构与功能研究提供了有用信息.     

Molecular Imprinting Fibrous Membranes of Poly（ acrylonitrile-co-acrylic acid） Prepared by Electrospinning

Introduction Overthepastfewdecades,molecularimprinting hasbeendescribedasatechnologyforpreparing“mo leculardoors”whichcanbematchedto“template keys”.Ithasbeenfoundtobeasimpleandeffective approachtointroducespecificrecognitionsitesintosyn theticpolymers…     

利用微波法合成二氧化钛纳米管

Titania nanotubes were synthesized by microwave method. The effects of raw materials, reaction time, NaOH solution concentration, and microwave power were studied. The samples were investigated by means of TEM, XRD, ICP techniques. Titania nanotubes having a hollow structure with an opening end were synthesized in NaOH solution (9~11 mol·L^-1) heated by 195 W microwave for over 60 min. The length of the titania nanotubes was about 1 μm and the average diameter of the nanotubes was about 8~10 nm.     

A spectroscopic study on the interaction between the anticancer drug erlotinib and human serum albumin

The interaction between erlotinib and human serum albumin (HSA) in simulated physiological conditions was investigated by spectroscopic methods. The results revealed that erlotinib caused the fluorescence quenching of HSA through a static quenching procedure. The binding constants at 293, 298, 303 and 308 K were obtained as 2.53 × 10⁵, 8.13 × 10⁴, 3.59 × 10⁴ and 1.93 × 10⁴ M^?1, respectively. There may be one binding site of erlotinib on HSA at 298 K. The thermodynamic parameters indicated that the interaction between erlotinib and HSA was driven mainly by hydrogen bonding or van der Waals forces. Synchronous fluorescence spectra, UV–Vis spectra, circular dichroism and Fourier Transform infrared spectroscopy results showed erlotinib binding slightly changed the conformation of HSA with secondary structural content changes. Förster resonance energy transfer study revealed high possibility of energy transfer with erlotinib-Trp-214 distance of 3.48 nm. The results of the present study may provide valuable information for studying the distribution, toxicological and pharmacological mechanisms of erlotinib in vivo.     

离子液体及其在电分析化学中的应用

离子液体由于具有导电性好、电化学电位窗口宽等特点而广泛应用于电分析化学领域.本文综述了2007年至2010年5月间,离子液体在电分析化学领域中的应用情况,引用参考文献111篇.     

粮谷中11种二硝基苯胺类除草剂残留量的气相色谱-串联质谱法测定

建立了粮谷中11种二硝基苯胺类除草剂残留量的气相色谱-串联质潜(GC-MS/MS)测定方法,样品经乙腈提取、QuEChERS法净化,采用GC-MS/MS在多反应监测模式下进行快速分析,外标法定量.在优化实验条件下,11种二硝基苯胺类除草剂的线性范围均为1.0～20.0μg/L,相关系数大于0.996,方法定量下限为5μ...     

间甲钴黏合体系在轮胎骨架材料中的黏合机理研究

为验证与进一步探索黏合树脂及钴盐对轮胎与镀铜钢丝帘线的增黏作用机理,选取传统黏合树脂R80与2种新型黏合树脂HT1005和H620,通过对2种新型黏合树脂的结构分析、橡胶硫化特性、静态T抽出测试与力学性能测试,并设计了一种新的黏合层强度测试方法与黏合层表征方法,进行机理探索,得出如下结论:含有羟基的极性黏合树脂在橡胶硫化时,会由于与非极性天然橡胶的极性差异产生的热力学不相容从而产生自动相分离,向橡胶与镀铜钢丝的界面层进行迁移汇集,且极性越高迁移能力越强,产生一个介于橡胶与镀铜钢丝之间的树脂富集层.因为黏合树脂交联反应温度为140℃左右,会在天然橡胶硫化反应时发生同步交联反应,黏合树脂形成的网络模量高于橡胶硫化网络,会增强镀铜钢丝与橡胶之间的黏合层强度,并形成一个镀铜钢丝与橡胶之间的模量过渡层,进一步增强黏合层.且极性越强,树脂网络交联程度与橡胶硫化网络交联程度越接近,增黏效果越好;钴盐会活化橡胶中的S,使更多的S迁移到镀铜钢丝表面从生成更多硫化亚铜键,增强黏合.