DNA分子在气液界面的组装相变特性及其LB膜结构研究

对十八胺与DNA在气液界面上组装及其相变过程进行了研究，利用AFM观察了不 同压力下转移的DNA复合LB膜结构。发现在低表面压时，DNA复合单分子膜表现为技 术发散的分形结构；随着压力的升高，DNA复合膜逐渐由紧密的网状排布结构变为 团聚的块状和团簇结构。表明通过调节膜压，可使膜内DNA分子的构象发生大的变 化，从而生成具有特定形态的二维纳米图案。这种具有特殊形态和结构的DNA LB膜 可望为合成新型生物纳米结构有序功能体系提供模板。     

牛血清白蛋白与两种金属配合物的作用研究

The interaction of Methylthymol Blue(MTB)-Zinc(Ⅱ) compound and Alizarin Red S(ARS)-Aluminum(Ⅲ) compound with Bovine serum albumin (BSA) was investigated by UV-Vis spectrophotometric method in acidic buffer solution. MTB-Zn(Ⅱ)-BSA was a blue color compound, which possesses maximum absorption at 613 nm with 172 nm, 174 nm and 18 nm of red shift compared to the MTB, MTB-BSA and MTB-Zn(Ⅱ) complexes respectively. Dual wavelength substantial amount ratio method, balance dialysis substantial amount ratio method and unity wavelength substantial amount ratio method were compared. The following results were obtained: the apparent molar absorptivity of MTB-Zn(Ⅱ) with BSA was ε=2.20×10⁴ L·mol^-1·cm^-1. Conditional proportion were defined, n_MTB∶n_Zn(Ⅱ)∶n_BSA=2∶2∶1; condition combination constant, K=2.07×1010. Combination proportion were defined, n_ARS∶n_Al(Ⅲ)∶n_BSA=6∶4∶1. Condition equilibrium constant of reaction of ARS-Al(Ⅲ) with BSA was K=8.80×10⁸. The apparent molar absorptivity of ε=2.65×10⁴ L·mol^-1·cm^-1. It is suggested that combination between BSA and MTB-Zn(Ⅲ) is due to coordination force. That combination between BSA and ARS-Al(Ⅲ) is due to the coordination bond and electrostatic force.     

高速逆流色谱与质谱联用在中药分析中的应用

高速逆流色谱 ( High- speed countercurrent chromatography,HSCCC)是新型的液 -液分配色谱技术 ,它利用多层螺旋管同步行星式离心运动 ,在短时间内实现样品在互不相溶的两相溶剂系统中的高效分配 ,从而实现样品分离[1] . HSCCC分离纯化后 ,若用 MS离线检测 ,此时须挥发原 HSCCC的溶剂体系 ,才能实现样品转移 ,还可能会带来样品污染 .HSCCC与 MS的联用克服了这些缺陷 ,具有很强的实用价值 .丹参酮 A( Tashinone A)是一种结晶性菲醌类化合物 [2 ] ,在丹参乙醚提取物中含量丰富 .本文采用正己烷 -乙醚 -乙醇 -水体系 ,将 HSCC…     

Effect of La2O3／γ—Al2O3 Catalyst on the Activation of CH4 and CO2 to C2 Hydrocarbons under Non—equilibrium Plasma

In the reaction of methane and carbon dioxide to C2 hydrocabons under non-equilibrium plasma, methane conversion was decreased,but selectivity of C2 hydroxarbons was increased when using La2O3/γ-Al2O3 as catalyst. So the yield of C2 hydrocarbons was higher than using plasma alone. The synergism of La2O3/γ-Al2O3 and plasma gave methane conversion of 24.9% and C2 yield of 18.1%. The distribution of C2 hydrocarbons changed when Pd-La2O3/γ-Al2O3 was used as catalyst,the major C2 product was ethylene.     

Synthesis of a Novel Core-shell Type Acrylic-polyurethane Hybrid Emulsion Containing Siloxane and Fluorine as well as Water and the Oil Resistances of Cured Film

Aqueous acrylic-polyurethane dispersions have become one of the major types of materials used in coating, paint and adhesive industries, because of excellent properties and environmental advantages1-5. However, some properties for cured film such as water…     

微波诱导低级醇的等离子体化学反应

微波诱导低级醇的等离子体化学反应王真，洪品杰，张承聪，戴树珊（云南大学化学系，昆明，６５００９１）关键词微波，等离子体化学，低级醇等离子体能产生大量的活性自由基、亚稳态粒子和激发态离子，它所包含的能量传递过程和反应过程不仅与反应碰撞理论有关，而且还涉...     

Crystal Structure of (1R,4R;1S,4S)2-Amino-3-Cyano-1,4-Diphenyl-2-Cyclopentene-1-ol

1INTRODUCTIONIntheearly1970'sthreegroupsofinvestigatorsL,~,'foundthatlow-valenttita-nium,preparedbythereactionofstrongreducingagentswithtitaniumtrichlorideortitaniumtetrachlorideintetrahydrofuran,canabstractoxygenfromketonesoraldehydes,leadingtotheforma-tionofolefins.Theinterestinthereactioninducedbylow--valenttitaniumreagentsisincreasingandalargenumberoffunctionalgroupscanbereduceds4-6).Recent-ly,wefoundthatthetitlecompoundisObtainedbycy-cllzatlonreactionof(3--oxo-1,3-diphenyl)propyl-pro…     

SYNTHESES OF THE SOLUBLE,HIGH MOLECULAR WEIGHT AND LADDERLIKE POLYPH ENYLSILSESQUIOXAN E AND COPOLYMETHYLPHENYLSILSESQUIOXANES BY PREAMMINOLYSIS METHOD

Soluble, high molecular weight (MW) and ladderlike polyphenylsilsesquioxane (LPPSQ) and its copolymers, ladderlike random and block copolymethyiphenylsilsesquioxanes(LR-PMPSQ and LB-PMPSQ)have been prepared by preamminolysis, hydrolysis and polycondensation reactions. The preparation method can be carried out easily at the temperature below 95℃with high yield of 95 %, instead of the conventional way by using high-boiling solvent and any reaction activator or by precipitation with methanol. Three kinds of ladderlike polymers have been characterized. The MW's of the polymers reached to 10~6 without noticeable gelling. The scheme for synthetic route has been proposed.     

Crystal Structure of Trans-2-Amino-3-Cyano-4-(3',4'-Methylenedioxyphenyl)-1-Phenyl-2-Cyclopentene-r-1-ol

1INTRODUCTIONIntheearlyseventiesthreegroupsofinvestigators('--"establishedthatlow--va-lenttitanium,preparedbythereactionofstrongreducingagentsontitaniumtrichlo-rideortitaniumtetrachlorideintetrahydrofuran,canabstractoxygenfromketonesoraldehydes,leadingtotheformationofolefins.Anincreasinginterestinthereac-tioninducedbylow--valenttitaniumreagentsisobservedandalargenumberoffunc-tionalgroupscanbereducedt4--6).However,thereactionoflow-valenttitaniumreagentwith4,4--dicyano--1,3--diaryl--l-butano…     

杂化能带与电子-声子耦合的本征上限

本文用角动量分波表象的能带论方法研究了杂化导带的一般性质。得出了电子态密度和分波含量的一般关系式。发现引用一个径向波函数φ_l的“相位函数”y_l,可以方便地对球对称势场造成的相移和φ_l的对数微商作解析近似处理。在此基础上研究了电子-声子耦合中的系数η的性质。论证了η有一个“本征上限”,并估计了它的量级。讨论了影响η强弱的一般规律,与实验现象作了比较。指出提高导带角动量杂化程度,特别是提高d导带中的f分波含量,以至试图实现似f导带,可能是强化电子-声子耦合潜力较大的探索方向。 关键词：