Synthesis and characterization of elastic aliphatic polyesters from sebacic acid, glycol and glycerol

A series of biodegradable polyesters have been prepared from sebacic acid (SA), glycol (Go) and glycerol (Ge) through a two-step process. First the linear prepolymers were prepared from SA and Go, then crosslinked polyesters were obtained from the prepolymer and Ge with different molar ratios. The resulting samples were characterized by Fourier Transform Infrared Spectrum (FTIR), X-ray Photoelectron Spectroscopy (XPS), and Differential Scanning Calorimetry (DSC). Dynamic Contact Angle tests (DCA) and mechanical tests were also investigated. The enzymatic degradation studies were performed at 37 °C in phosphate buffer solution with porcine pancreas lipase. The resultant polyesters were transparent, flexible, insoluble in organic solvents, and the surfaces of the polyesters were hydrophilic. Young’s modulus, tensile strength, glass transition temperature (T_g) and the degree of enzymatic degradation increased with increasing the content of Ge. It was also worth noticing that the surface content of -COOC- groups was a key factor in the enzymatic degradability.     

A preliminary study of new imaging agents on inflammatory lesions

The purpose of the investigation was to evaluate the feasibility of imaging inflammatory lesions with five small molecular weight complexes of ^99mTc. The labeling yields of D-glucaric acid (D-Gca), citric acid (Cit), DL-malic acid (DL-Mal), L-malic acid (L-Mal) and tartaric acid (Tar) were all more than 90%. The percentage uptake/g tissue of them and ^99mTc-pertechnetate (P) in mice with turpentine-induced abscesses and abscess/muscle (A/M), blood (A/B), liver (A/L), kidney (A/K) concentration ratios were calculated. The maximum A/M ratios were 4.02±0.21 (Cit, 3h), 4.30±0.77 (D-Gca, 3h), 4.04±0.21 (DL-Mal, 6h), 3.50±0.23 (L-Mal, 1h), 3.20±0.17 (Tar, 1h) and 3.23±0.41 (P, 1h) respectively. The scintigram was obtained in a rabbit with turpentine-induced abscess after ^99mTc-D-Gca i.v. injection. Results demonstrated they all can accumulate in inflammatory lesions. Of them, ^99mTc-D-Gca is probably a potential imaging agent on inflammatory lesions.     

Copper-catalyzed amination of aryl halides with nitrogen-containing heterocycle using hippuric acid as the new ligand

An efficient copper-catalyzed amination of nitrogen-containing heterocycles with various aryl halides has been developed. Commercially available and inexpensive hippuric acid is a novel ligand to afford the coupling products in moderate to excellent yields.     

光子晶体在分析化学中的应用

光子晶体是一新兴的光学材料,正越来越多地应用于分析化学领域,有可能成为新的研究热点。本文着重介绍与分析化学相关的光子晶体研究,特别关注其在色谱、毛细管与芯片电泳等分离分析方面的应用。     

一类热弹性板的空间衰减估计

研究了二维空间中半无限带形区域上一类含有双调和算子的热弹性系统板解的空间性质.首先构造一个能量表达式,然后利用微分不等式技术,推导出该能量表达式是可由它本身的一阶导数控制的微分不等式,最后得到解的空间衰减估计.该结果可看成是Saint-Venant原则在双曲抛物耦合双调和方程组上的应用.     

含银偏振玻璃的制备及光学性能

研究了拉伸还原法制备含银Ｒ２Ｏ－Ｂ２Ｏ３－Ａｌ２Ｏ３－ＳｉＯ２系统偏振玻璃的工艺,得到了工艺波段在６００￣１４００ｎｍ、透光度９０％、消光比１６２：１的玻璃偏振片,着重探讨了拉伸比对偏光性能的影响,并对偏振机理作出了解释。     

稀有气体卤化物离子准分子XUV跃迁参数计算

利用推导的修正的Rittner势,采用ab initio高斯80程序,首次计算了稀有气体卤化物势能曲线、光谱常数、辐射波长及相关的能级寿命,自发发射,受激发射系数和增益截面,从而给出了产生XUV激光的有关参数和依据,初步认为稀有气体卤化物离子准分子可能是获得XUV波段激光的优秀侯选者。     

The Hausdorff dimension of chaotic sets for interval self-maps

We obtain two sufficient conditions for an interval self-map to have a chaotic set with positive Hausdorff dimension. Furthermore, we point out that for any interval Lipschitz maps with positive topological entropy there is a chaotic set with positive Hausdorff dimension.