Solvothermal Synthesis, Crystal Structure and Electrochemical Property of Complex [Co(p-MBA)2(2,2''-bipy)(H2O)]·(H2O)

One novel complex [Co(p-MBA)2(2,2'-bipy)(H2O)]·(H2O) has been synthesized by the reaction of p-methylbenzoic acid with 2,2'-bipyridine in the solvent mixture of water and methanol. It crystallizes in triclinic, space group P-1 with a=0.70479(14), b=1.1211(2), c=1.6718(3) nm, α=103.806(3), β=90.795(3), γ=104.207(3)°, V=1.2399(4) nm3, Mr=512.41, Dc=1.373 g/cm3, Z=2, F(000)=532, μ=0.733 mm-1, R=0.0432 and wR=0.0957. The crystal structural analysis shows that the cobalt atom is coordinated with three oxygen atoms from two p-methylbenzoic acids and one water molecule and two nitrogen atoms from one 2,2'-bipyridine,forming a distorted square-pyramidal coordination geometry. The cyclic voltammetry behavior of the complex is also reported.     

含L－氨基酸结构的手性液晶化合物的合成及其相变行为

合成了９种具Ｌ－氨基酸衍生物结构的介晶化合物（Ｉ－Ⅲ，Ⅳａｂ，Ⅴａ，ｂ，Ⅵａ，ｂ）、４种氨基酸衍生物（Ａ１－４）和６种介晶化合物（Ｍ１－６）．新化合物（Ⅰ－Ⅲ，Ⅳａ，ｂ，Ⅴａ，ｂ，Ⅵａ，ｂ，Ａ４，Ｍ３－６）的化学结构通过ＩＲ、１ＨＮＭＲ和元素分析证实；并用偏光显微观察和ＤＳＣ分析研究了其相变行为，结果表明有８种化合物（Ｍ３－６，Ⅵａ，ｂ，Ⅴｂ，Ⅵｂ）呈现液晶相变。测定了它们的比旋光度。通过Ｘ射线衍射研究了化合物Ⅵｈ１２０～１３０℃和Ⅵｂ１７０～１８０℃的近晶结构，Ⅵｂ显，Ⅵｂ呈。测定了化合物Ⅳｂ的电滞回线，证明其具铁电性。     

聚苯基膦酸双酚A酯的合成与表征

聚苯基膦酸双酚Ａ酯的合成与表征唐旭东陈晓婷王玉忠杨科珂王波（四川联合大学化学系成都６１００６４）吴大诚（四川联合大学轻纺学院成都６１００６５）关键词聚膦酸酯，阻燃剂，熔融缩聚，热性能聚膦酸酯类化合物是一类重要的磷系阻燃剂［１～３］，与传统的非聚...     

Evaporation behavior of water from aqueous dispersions of multihollow particles prepared by the stepwise alkali/acid method

In order to clarify the formation mechanism of multihollow structures inside styrene–methacrylic acid copolymer particles prepared by the stepwise alkali/acid method, which we proposed in 1990, the evaporation behavior of water from aqueous dispersions of the original carboxylated particles and those after the alkali treatment and the stepwise alkali/acid treatments was examined. It is concluded that the particle after the alkali treatment had a number of small water pools inside. Received: 22 February 2001 Accepted: 20 June 2001     

Photo-induced Charge Separation of p-Tricyanovinyl-N,N-Dialkylanilines

In this paper,p-tricyanovinyl-N,N-dialkylanilines were synthesized as model compounds and through their spectroscopic behavior,the photo-induced electron transfer,charge separation were discussed and the aggregation in DMSO-H_2O system was investigated.     

Geometric critical exponent inequalities for general random cluster models

A set of new critical exponent inequalities,d(1 –1 /)2 –, dv(1 – 1/), andd> 1, is proved for a general class of random cluster models, which includes (independent or dependent) percolations, lattice animals (with any interactions), and various stochastic cluster growth models. The inequalities imply that the critical phenomena in the models are inevitably not mean-field-like in the dimensions one, two, and three.The present work was reported at the 56th Statistical Mechanics Meeting (Rutgers, December 1986).     

Critical behavior of the two-dimensional first passage time

We study the two-dimensional first passage problem in which bonds have zero and unit passage times with probabilityp and 1–p, respectively. We prove that as the zero-time bonds approach the percolation thresholdp _c, the first passage time exhibits the same critical behavior as the correlation function of the underlying percolation problem. In particular, if the correlation length obeys(p) ¦p–p _c¦^–v, then the first passage time constant satisfies(p)¦p–p _c¦^v. At p_c, where it has been asserted that the first passage time from 0 tox scales as ¦x¦ to a power with 0<<1, we show that the passage times grow like log ¦x¦, i.e., the fluid spreads exponentially rapidly.     

尼龙66/蒙脱土复合材料结晶行为的研究

在密炼机中采用熔融共混法制备蒙脱土重量分数为 2 5 %、4 5 %的尼龙 6 6 /蒙脱土复合材料 .通过DSC法对非等温结晶行为及在 2 2 8～ 2 4 0℃范围内的等温结晶行为进行研究 ,并与纯尼龙 6 6进行比较 .从其等温和非等温结晶行为的研究表明 ,蒙脱土起成核剂的作用 ,它的填入使尼龙 6 6结晶速率提高 ,但填料与基体间的相互作用使其链段运动困难 ,结晶活化能提高 ;在研究的填料含量变化范围内 ,结晶行为变化不大 ,并且找到该复合材料在 2 2 8～ 2 34℃范围结晶对温度的不敏感区 ;对非等温结晶过程分析 ,刘结平 莫志深方程是适用的 ,而Ozawa方程则是不适用的 .     

Elastic behavior of non-Gaussian polymethylene chains

In this paper, elastic behaviors of non-Gaussian polymethylene (PM) chains with chain length N=100 are investigated by rotational isomeric state model. Here the tetrahedral lattice of PM chain and the non-local interaction of Sutherland potential are adopted. In the metropolis movement of PM chain, a four-bond movement model is used. The average energy and average Helmholtz free energy with various elongation ratios λ are calculated by Monte Carlo simulation method. The average energy increases with elongation ratio λ and the average Helmholtz free energy decreases with elongation ratio λ. The elastic force f and the energy contribution to elastic force f_u can be obtained from f=∂〈A〉/∂r and f=∂〈U〉/∂r. We find that the elastic force f increases with elongation ratio λ and the energy contribution f_u decreases with elongation ratio λ, and f_u is less than zero. The ratio f_u/f is close to −0.21 for λ?1.25, and −0.04 to −0.35 for λ>1.25 at T=364 K. In our calculation, the rubber elasticity may be discussed in terms of the chemical structure of polymer chains.     

Synthesis and characterization of thermoresponsive isopropylacrylamide-acrylamide hydrogels

In this study, hydrogels of poly(N-isopropylacrylamide-co-acrylamide) having a thermoresponsive character were prepared by a redox polymerization method. NIPAM-co-AAm hydrogels with different thermoresponsive properties were obtained by changing the initial NIPAM/AAm mole ratio and crosslinker concentration.Equilibrium-swelling ratio, dynamic swelling ratio and dynamic deswelling ratio were evaluated for all hydrogel systems. The fast shrinking was observed with all gels. The time required for equilibrium shrinking increased with the increase of acrylamide content in the gel.