Experimental and theoretical study of the nonlinear response of agiant magnetostrictive rod

In this paper, a magnetomechanical coupling constitutive relation of the giant magnetostrictive material was investigated experimentally and theoretically. A grain-oriented magnetostrictive rod of iron and rare earth was tested under a combined magnetomechanical loading. Two types of experimental curves were obtained, i.e., the magnetostrictive curve of the extensional strain vs the magnetic field, and the curve of the magnetic polarization intensity vs the pre-stress. A new theoretical constitutive model, based on the density of domain switching, is developed. Comparison of the theoretical predictions with the experimental results indicates that this model can capture the main characteristics of the magnetoelastic coupling deformation of a giant magnetostrictive rod. The project supported by the National Natural Science Foundation of China (10025209, 10132010, 10102007)     

2-(5-甲基-1,3,4-噻二唑)-硫乙酸镍(Ⅱ)配合物的合成和晶体结构

本文合成了2个镍配合物[Ni(mtyaa)2(H2O)4]·4(H2O)(1)和[Ni(4,4′-bipy)2(mtyaa)2(H2O)2]·2H2O(2)(Hmtyaa=2-(5-甲基-1,3,4-噻二唑)-硫乙酸;4,4′-bipy=4,4′-联吡啶),用X-射线单晶衍射仪测定了配合物的单晶结构,并对它进行了元素分析、红外光谱、热重和粉末X-射线衍射等表征。配合物1和2的晶体分别属于三斜晶系和单斜晶系,空间群分别为P1和P21/n。X-射线单晶结构分析表明配合物1和2中镍原子均采取六配位扭曲的八面体配位模式。在配合物1中配位水和游离水分子与羧基氧之间的氢键作用将单分子结构连成三维网状结构。配合物2中配位水和游离水分子与羧基氧以及配体中的氮原子之间的氢键作用将链连接成二维层状结构。     

小分子α-螺旋模拟物

本文综述了近年来小分子α-螺旋模拟物的研究进展,介绍了α-螺旋结构在蛋白质相互作用中的重要性以及小分子α-螺旋模拟物在药物化学领域的应用。概括了联苯结构、酰胺结构、哒嗪结构及其他杂环结构小分子α-螺旋模拟物的最新进展,并介绍了小分子α-螺旋模拟物在蛋白质相互作用抑制剂方面的应用。总结了目前已有的小分子α-螺旋模拟物存在的一些不足之处,并对今后该研究领域的发展方向进行了展望。     

硫代二草酰二(3,5-二甲基嘧啶)锰配合物的合成及其与DNA的相互作用

以4,6-二甲基-2-巯基嘧啶和草酰氯为原料合成了硫代二草酰二(3,5-二甲基嘧啶)(L)及其锰配合物;采用红外光谱、紫外光谱、核磁共振谱对其结构进行了表征,同时研究了锰配合物与DNA的相互作用.结果表明,锰配合物的阳离子与DNA磷酸基团的氧负离子形成静电结合.     

比较研究山姜素和豆蔻明与人-γ球蛋白的相互作用

将互为同分异构体的两种植物药活性组分山姜素和豆蔻明作为研究对象,应用荧光光谱法、紫外光谱法以及红外光谱法并结合分子对接技术首次对这两种黄酮类化合物与人-γ球蛋白(Human gammagobulin,HG)的相互作用进行了详细研究.荧光光谱法的研究结果表明,这两种药物均与HG有较强的相互作用(结合常数均在104～105之间);山姜素对HG表现为静态猝灭机理,而豆蔻明对HG表现出非常少见的动态猝灭机理.比较不同温度(298,308和318K)下两种药物与蛋白相互作用的结合参数都有所差别,维持药物-HG体系的作用力也不同.山姜素和豆蔻明分子与HG色氨酸残基间的结合距离r值(分别为3.88和4.52nm)都小于7nm,说明发生了能量转移.同步荧光与红外光谱法定性及定量地研究了药物对HG二级结构的不同影响程度.两种分子对接结果表明了这两种药物与HG的结合区域.     

在导电高分子薄膜表面沉积密度可控的银纳米粒子

<正>由于导电高分子的导电性和化学性质可以在导体和半导体区间内快速调节[1],因此其复合材料受到了越来越多的关注[2].金属纳米粒子在光电子器件、检测及传感等诸多领域表现出独特的性能[3],在生物技术领域中的重要性尤为突出[4].因此,如果将导电高分子和金属纳米粒子结合在一起,将有利于拓展导电高分子的应用范围.本文研究了银纳米粒子在聚苯胺薄膜表面的沉积行为,分别用原子力显微镜(AFM)和扫描电子显     

聚γ-(2-脲基噻唑)丙基甲基硅氧烷金属配合物的制备及磁学性能研究

合成了一种新的γ-(2-脲基噻唑)丙基甲基二乙氧基硅烷单体及聚硅氧烷聚合物,采用溶胶-凝胶法制备了聚硅氧烷的铜、镍金属离子的配合物,利用红外光谱、核磁共振氢谱及质谱等手段表证了其结构.并分析和讨论了它们的磁学性能.此类金属配合物在低温区,磁化率倒数与温度的关系不服从居里-外斯定律,存在着铁磁耦合,是一类有机铁磁体.另外,发现在含噻唑基团的硅氧烷链中引入5倍当量的二甲基硅氧烷链节,其居里-外斯温度增大了近2倍.     

Formation Mechanism and Stability Study of Konjac Glucomannan Helical Structure

The formation mechanism and stability of konjac glucomannan (KGM) helical structure were investigated by molecular dynamic simulation and experimental method. The results indicate that the molecular conformation of KGM is a non-typical helical structure. In detail, helical structure of KGM is mainly sustained by acetyl group, whose size and stability are affected by the molecular polymerization degree of KGM. In vacuum among the non-bonding interactions, electrostatic force is the greatest factor affecting its helical structure, but in water solution, hydrogen bond affects the helical arrangement greatly. To our interest, temperature exhibits a reversible destroying effect to some extent; the helical structure will disappear completely and present a ruleless clew-like arrangement till 341 K. This work suggests that the method of combining molecular dynamic simulation and experiment tools can be effective in the study of KGM helical structure.     

Synthesis and Single-crystal Structure of a Silver(Ⅰ) Carboxyarylphosphonate: [Ag(H_2BCP)(4,4'-bipy)]·2H_2O

The title compound, a novel Ag(Ⅰ) carboxyarylphosphonate [Ag(H2BCP)(4,4'- bipy)]·2H2O (H3BCP = p-H2O3PCH2C6H4COOH, 4,4'-bipy = 4,4'-bipyridine), was synthesized by a hydrothermal reaction and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. It belongs to monoclinic system, space group P21/c with a = 5.7038(11), b = 22.397(4), c = 5.602(4) ?, β = 106.26(3)°, V = 1913.4(7) 3, Z = 4, C18H20N2O7PAg, Mr = 515.20, Dc = 1.788 g/cm3, μ = 1.182 mm-1, F(000) = 1040, the final R = 0.0404 and wR = 0.1216 for 4178 observed reflections with I 2σ(Ⅰ). In the structure, the Ag(Ⅰ) cations are bridged by 4,4'-bipy to give rise to 1D chains running along the b axis. These chains are linked further by the interactions of O (from BCP ligands) and Ag atoms to yield 2D layers. Hydrogen bonding interactions and weak π-π stacking interactions between 4,4'-bipy rings assemble such adjacent layers to generate a 3D supramolecular architecture.     

Two Discrete Cu-Complexes Constructed from a Multidentate N-Containing Dinucleating Ligand

Two comparable discrete complexes [CuⅡ(CH3CN)2L2]·2(ClO4) 1 and [CuI2I2L2]·(DMF)2 2 were successfully synthesized by the reaction of CuⅡ and CuⅠ salts with a novel dinucleating ligand 2,5-bis(3-pyridinylmethylthio)-1,3,4-thiadiazole)(L),respectively.Complex 1 presents a single nuclear structure while 2 has a dimeric structure where two CuI ions are doubly bridged by halide ions in a μ2-fashion.Both discrete molecules were outspreaded into a one-dimensional supramolecular chain via aromatic interactions such as C-H…π and π…π interactions.