一种双肟四核铜(Ⅱ)配合物的合成、结构及热稳定性研究

由螯合双肟配体3,3′-二甲氧基-2,2′-[(1,3-亚丙基)二氧双(氮次甲基)]二酚(H₂L)与四水合苦味酸铜作用,合成了一种新的四核铜(Ⅱ)配合物 [Cu₄L₂(pic)₄(H₂O)₂]·2CH₃COCH₃·2H₂O(pic^-=苦味酸根)。用X-射线单晶衍射仪测定了该配合物的晶体结构：配合物属单斜晶系,P2₁/c空间群,由4个Cu^Ⅱ离子,2个四齿的L2-单元,4个配位的苦味酸根(pic^-),2个配位的水分子,2个结晶的丙酮分子和2个结晶的水分子组成。Cu^Ⅱ离子的配位数为6,都具有稍微扭曲的八面体结构。且配合物分子通过分子间O-H…O氢键作用形成了1个二维超分子结构。     

Effect of Asymmetric Potential and Gaussian Colored Noise on Stochastic Resonance

The phenomenon of stochastic resonance （SR） in a bistable nonlinear system is studied when the system is driven by the asymmetric potential and additive Gaussian colored noise. Using the unified colored noise approximation method, the additive Gaussian colored noise can be simplified to additive Gaussian white noise. The signal-to-noise ratio （SNR） is calculated according to the generalized two-state theory （shown in [H.S. Wio and S. Bouzat, Brazilian J.Phys. 29 （1999） 136]）. We find that the SNR increases with the proximity of a to zero. In addition, the correlation time T between the additive Gaussian colored noise is also an ingredient to improve SR. The shorter the correlation time T between the Gaussian additive colored noise is, the higher of the peak value of SNR.     

基于2-氨基-3-羟基-吡啶Schiff碱的双核Ni(Ⅱ)和Zn(Ⅱ)配合物:合成、超分子结构和光谱性质

合成了2个2-氨基-3-羟基-吡啶Schiff碱双核Ni（Ⅱ）和Zn（Ⅱ）配合物,[Ni（L¹）（DMF）]₂（1）（H₂L¹=4-羟基-3-（（3-羟基-吡啶-2-亚氨基））-苯并吡喃-2-酮）和[Zn（L²）（H₂O）]₂·2DMF（2）（H₂L²=2-（（3,5-二溴-2-羟基）-氨基）-吡啶-3-醇）,并通过元素分析、红外光谱、紫外-可见吸收光谱、荧光光谱及X射线单晶衍射分析等手段进行了表征。X射线单晶衍射分析结果表明：配合物1和2均具有双核结构,均由2个金属离子和2个配体单元以及2个配位的溶剂分子组成,不同的是配合物2含有2个溶剂分子。配合物1和2都是单斜晶系、P2₁/c空间群,且中心金属Ni（Ⅱ）和Zn（Ⅱ）离子的空间构型均为五配位的扭曲的四方锥。此外,配合物1和2通过分子间氢键、C-H…π及π…π作用形成3D超分子结构。此外,讨论了H₂L¹,H₂L²及其相应的Ni（Ⅱ）和Zn（Ⅱ）配合物的荧光性质。配体H₂L¹和H₂L²呈现蓝色发射,最大发射波长λ_em分别为457和473 nm,而配合物1和2显示绿色发射,λ_em分别为543和538 nm。     

Spatially Periodic System with Infinite Globally Coupled Oscillators Driven by Temporal-Spatial Noise

In this paper, we study spatially periodic system with infinite globally coupled oscillators driven by temporal-spatial noise and subject to a constant force. The results show that the system exhibits the phenomena of the non-equilibrium phase transition, transport of particles, and the anomalous hysteresis cycle for the mean field and the probability current.     

Flux for a System with Infinite Globally Coupled Oscillators Driven by Temporal-Spatial Noises

The transport of a spatially periodic system with infinite globally coupled oscillators driven by temporalspatial noises is investigated. The probability current shows that the correlation of the multiplicative noises with the space, the spatial asymmetry, and the coupling among the different oscillators are ingredients for the transport of particles. It is a new phenomenon that the correlation of the multiplicative noises with the space can induce the nonzero flux.     

应用荧光光谱法研究植物LEA3蛋白11-氨基酸基序的保护功能

胚胎晚期富集蛋白(late embryogenesis abundant,LEA)是增强生物抵抗干旱、低温和盐渍等多种胁迫的重要功能蛋白,但其保护机理仍不清楚.本文利用紫外光谱法证实,含多拷贝11-氨基酸基序的多肽(如PM2D和PM2E)可较好的保护经冻融的乳酸脱氢酶(LDH)活性.进一步通过荧光光谱法证实,含多拷贝11-氨基酸基序的多肽可通过多位点协同结合模式,稳定LDH酶的结构.而含低拷贝11-氨基酸基序的多肽(如PM2F和PM2G)与LDH酶只有一种结合位点,二者的结合强度较弱,因而不能表现出对LDH酶活性的保护作用.此外,含多拷贝11-氨基酸的多肽与海藻糖在保护LDH酶活性上存在协同作用,且二者有着不同的保护机理.     

Synthesis and Crystal Structure of 2-O-(2-hydroxyethyl)-D-glucose

The title compound, 2-O-(2-hydroxyethyl)-D-glucose (C8H16O7 , Mr = 224.21), has been synthesized and its structure was characterized by using NMR spectrum and X-ray single-crystal diffraction. This molecule crystallizes in the monoclinic system, space group P21 , with a = 8.399(17), b = 6.620(14), c = 9.81(2), β = 115.110(17)°, V = 493.7(18)3 , Z = 2, Dc = 1.508 mg/m3 , μ = 0.13 mm-1 , F(000) = 240, the final R = 0.0464 and wR = 0.115 for 1521 observed reflections (Ⅰ > 2σ(Ⅰ)). X-ray crystal structure analysis revealed that the conformation of the pyranosyl ring existed in a slightly distorted 4C1 chair conformation (Cremer-Pople puckering parameters of Q = 0.573(4) , θ = 6.7(3)° and Ф = -5.2(2) °). The molecule exists as a monomer in the solid state, whose conformation is stabilized via multiple inter- and intramolecular hydrogen bonds.