二苯并-18-冠-6与碱金属苦味酸盐在氯仿中的相互作用

研究一种方法以测定二苯并-18-冠-6在氯仿中与碱金属苦味酸盐相互作用的若干参数。这些参数是:络合物的无限稀释摩尔电导 A_0,络合物的解离常数 K_d(或 k_d),络合物中冠醚与盐的分子比,冠醚对苦味酸盐的络合常数 K_c(或 k_c),以及冠醚存在下苦味酸盐紧密离子对的饱和浓度[MA]等。     

荧光猝灭法测定痕量六价铬

基于六价铬与碘化钾反应生产了单质碘，碘可以使2′，7′－二氯荧光素（DCF）发生荧光猝来，从而间接测定六价铬。六价铬浓度在0．20－2．50μg/25ml范围内，荧光强度差值与六价铬浓度呈线性关系，线性回归方程△F=12．12 0．19，相关系数r=0.9993，检出限为0．10μg/ml。方法简便，灵敏度较高，已用于合成样中六价铬的测定。回收率在100％－103％，结果满意。     

色谱分析发展简史及其给我们的启示

简要回顾了色谱分析技术的发展史，厘清了某些中文文献中的不妥表述。通过分析色谱发展过程中的几个重要突破，总结了在科学技术创新方面给我们的启示：（1）基础研究始终是色谱技术进步的源泉；（2）社会发展的需求是各种色谱方法创新的驱动力；（3）学科交叉是色谱分析技术创新的重要途径；（4）不懈坚持和勇于探索是科学技术创新的必要条件。最后对色谱发展的前景作了展望。     

芳基-芳基偶联反应的研究进展

综述了近年来芳基-芳基偶联反应的研究进展, 包括不同类型芳基-芳基偶联反应的特点、机理和应用, 尤其是对立体选择性和区域选择性的偶联方法进行了重点介绍.     

Fe3+-TiO2/SiO2光催化降解罗丹明B的研究

以硅胶为载体,采用溶胶-凝胶法制备了不同掺杂量的Fe3+-TiO2/SiO2光催化剂,并采用SEM,Raman和DRS等手段对其进行了分析和表征.以氙灯为光源,通过对可溶性染料罗丹明B的降解反应,考察了Fe3+-TiO2/SiO2催化剂的光催化活性,探讨了光催化反应中溶液pH值和起始浓度对催化反应的影响.     

Synthesis of 1, 4-Bis[3-N-propionyl-2-aryl-1, 3, 4- oxadiazoline-5-yl]phenylenes

1, 3, 4-Oxadiazoline derivatives are found to possess significant biological activities such as antifungal1, insecticidal2, CNS depressant3-5, anticonvulsant effects and plant growth accelerator. They are highly important heterocycles, and have been used …     

乙烯在纳米催化剂InVO4-TiO2上的可见光降解

The InVO₄-TiO₂ nano-crystalline photocatalyst was prepared by sol-gel method and characterized by DRS, FTIR, Raman and XRD. The photocatalytic activities of the prepared sample were investigated by photocatalytic degradation of ethylene in the gaseous phase under visible light irradiation (λ>450 nm). The results indicate that both of pure TiO₂ and InVO₄ or their simple mixture show no photocatalytic activities for degradation of ethylene under visible light irradiation. However, as-synthesized InVO₄-TiO₂ catalyzes the degradation of ethylene into CO₂ under visible light irradiation. In addition, the interaction between InVO₄ and TiO₂ results in some structural distortion to all the crystal forms of TiO₂ in as-synthesized catalyst InVO₄-TiO₂.     

Synthesis, Crystal Structure and Photoluminescent Property of a Novel Silver(Ⅰ) Compound {[Ag(bpp)]2(Hphth)(NO3)·(H2O)2}n

Self-assembly of Ag(Ⅰ) nitrate, 1,3-bis(4-pyridyl)propane (bpp) and phthalic acid monopotassium salt (KHphth) in CH3OH-H2O solution produced the title complex,{[Ag(bpp)]2(Hphth)(NO3)·(H2O)2}n, which was characterized by single-crystal X-ray diffraction,elemental analysis, IR spectrum, and photoluminescent spectrum. Single-crystal X-ray analysis revealed that the complex crystallizes in a monoclinic system, space group P21/c, with α =15.4174(5), b = 8.6398(2), c = 25.2466(8) (A), β = 91.072(1)°, V = 3362.34(17) (A)3, Z = 4,C34H37N5O9Ag2, Mr = 875.43, Dc = 1.729 g/cm3, μ = 1.228 mm-1, F(000) = 1768, the final R =0.0749 and wR = 0.1580 for 5754 reflections with I ＞ 2σ(I). The Ag atom is coordinated by two N atoms from two bpp molecules in an approximately linear geometry. The Ag(Ⅰ) ions are linked by the bpp molecules to form one-dimensional zigzag chains propagating along the c axis. The Hphth-and nitrate counter-ions are bridged by solvent water molecules through hydrogen bonds to generate a one-dimensional chain extending along the b axis. Electrostatic interactions between cations and anions, extensive hydrogen bonds and π-π interactions are responsible for the three-dimensional supramolecular structure. In the solid state, the compound exhibits blue photoluminescence with the maximum at 436 nm upon excitation at 344 nm.     

栝楼蛋白 2: 栝楼蛋白部分化学结构的初步测定

栝楼蛋白(Trichobitacin)是从栝楼(Trichosanthes kirilowiiMaxim, Cucurbitaceae)中新发现的核糖体失活蛋白, 分子量为27,228; pI为9.6。应用基质辅助的激光解析飞行时间质谱(MALDI-TOF-MS)和快原子轰击质谱法(FAB-MS)分别测定胰蛋白酶酶解栝楼蛋白和天花粉蛋白(Trichosanthin)的混合肽质谱, 通过比较发现了一些分子量相同的肽。由于这两种蛋白质都来源于栝楼块根, 同源性比较强, 所以这些肽序列在两种蛋白质中基本一样; 再结合蛋白N-端自动顺序仪测定栝楼蛋白N-端的结果, 确定了栝楼蛋白N-端38个氨基酸的顺序, 栝楼蛋白经胰蛋白酶酶解后所得肽段用HPLC分离纯化, 再用蛋白质自动顺序仪, DABITC/PITC双偶合手工法和质谱法共确定了栝楼蛋白N-端, C-端等100多个氨基酸残基的序列。     

The solid state reactions of o-aminobenzoic acid with Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ), Mn(Ⅱ) acetate hydrate at room temperature

The solid-solid state reactions of o-aminobenzoic acid with Zn(OAc)2.2H2O, Cu(OAc)2 .H2O, Ni(OAc)2.4H2O and Mn(OAc)2.4H2O result in the formation of corresponding complexes M(OAB)2 (M = Zn(Ⅱ), Cu(Ⅱ), Ni(Ⅱ), Mn(IⅡ)). XRD, IR and elemental analysis methods have been used to characterize the solid products. The activation energies of these reactions, which are calculated from the kinetic data obtained by means of the isothermal electrical conductivity measurement method, have been found to increase in the order: Cu(OAc)2.H2O(37.7 kJ.mol-1)~Mn(OAc)2.4H2O (39.7kJ.mol-1) < Zn(OAc)2.2H2O (56.3 kJ.mol-1) < Ni(OAc)2.4H2O (85.2 kJ.mol-1). The trend is related to their crystal structures.