交联壳聚糖／聚醚半互穿聚合物网络水凝胶中水的状态

合成了一种由戊二醛交联的壳聚糖与聚醚形成的半互穿聚合物网络的水凝胶，用ＤＳＣ法并结合ＩＲ光谱研究了该水凝胶中水的状态及水与聚合网络间的相互作用。     

基于吡啶基苯甲酸盐的两个银(Ⅰ)配合物的合成、晶体结构及荧光性质

合成了2个含有吡啶基苯甲酸盐的银(Ⅰ)配合物,即[Ag₂(PPh₃)₂(4,4-pybz)₂(H₂O)₂]_n(1)和[Ag₂(PPh₃)₂(4,3-pybz)₂]·2CH₃OH(2)(PPh₃=三苯基膦,4, 4-pybz=4-吡啶-4-基-苯甲酸根, 4,3-pybz=4-吡啶-3-基-苯甲酸根),并通过红外光谱、元素分析和荧光光谱进行分析和表征,它们的结构由X射线单晶衍射测定。在不同的溶剂下,2个配合物由AgBF₄、PPh₃和不同的吡啶苯甲酸在氨水作用下,以1:1:1的比例反应而成。在配合物1中,所有的银原子由吡啶基苯甲酸桥连形成一维链状结构。在配合物2中,2个银原子通过2个4-吡啶-3-基-苯甲酸根配体形成双核结构。在荧光光谱中,在发射状态下所有的峰均来源于配体的π-π*跃迁。     

形状记忆高分子材料的新型共混制备方法

形状记忆高分子材料(shape memory polymers,SMPs)作为一种特点突出、性能优良的智能材料具有极高的研究和实用价值,受到各国研究人员的广泛关注,新的制备方法和材料体系不断涌现,显示出巨大的发展潜力.本文总结了近年来出现的以共混方式为基础的多种重要制备方法,包括聚合物与聚合物直接熔融共混、溶液共混、借助增容剂或交联剂进行共混、通过新型微层共挤出技术进行交替层状共混、以及利用静电纺丝技术进行三维网络结构共混等.相较于化学合成方法,这些共混方法具有操作简单、原料易得、制备效率高、产品性能调节方便、制备过程更为环保等优点,并且能够得到与化学合成方法性能相同甚至更好的产品,优势突出,是今后制备形状记忆高分子材料的一大趋势.本文从这些新型共混材料的制备过程、微观结构、形状记忆性能等角度详细分析了不同方法的特点和优势.这些近年来出现的共混制备方法对于形状记忆高分子材料的发展和未来应用将是至关重要的.     

东南极拉斯曼丘陵及其邻区的泛非热事件

本文以Sm-Nd内部等时年龄,单颗粒锆石~(207)Pb-~(206)Pb逐层蒸发年龄和黑云母~(40)Ar/~(39)Ar坪年龄为根据,论述了东南极拉斯曼丘陵泛非热事件。野外地质和同位素年代学的证据表明,该热事件不仅有区域强烈的部分熔融,而且还有低压麻粒岩相变质。它的产生可能与冈瓦纳古陆的最终形成有关。     

连续小波变换-独立成分回归算法及其在多组分分析中的应用

采用连续小波变换（CWT）对光谱数据进行处理，用独立成分分析（ICA）进行特征提取，再用回归分析方法对被测组分进行测定，建立了连续小波变换一独立成分回归（CWT-ICR）方法。方法用于肉样品中水分、脂肪和蛋白质多组分的同时测定，所得结果与化学法测得结果相符。     

冰箱除臭器对乙硫醇驱除效率的气相色谱测定

报道一种快速检测冰箱除臭器对乙硫醇驱除效率的气相色谱分析方法。此法可同时通过谱图判断除臭器的类型。     

用变速升温法研究高聚物的热氧化机理(一)

关于高聚物的热裂解与热氧化已进行过大量工作,并取得许多成果,但这些工作都是在等温或某一升温速度下进行,此时各人所用升温速度不同,因高聚物的热裂解与热氧化均为很复杂的过程,此时除裂解、氧化等化学反应外,更涉及传质、传热等过程,故我们认为时间因素即升温速度对热裂解与热氧化是有影响的,而在不同升温速度下,研究高聚物的热裂解与热     

A COMPARISON OF DENATURATION AND INACTIVATION RATES OF CREATINE KINASE IN GUANIDINE SOLUTIONS

Both the denaturation, as followed by UV absorbance and fluorescence changes, and inac-tivation of creatine kinase in guanidine solutions have been found to be first order reactions.In 3 M guanidine, at 30℃, the inactivation rate constant was found to be 5.9 sec~(-1) and thedenaturation rate constant 1.9 sec~(-1). At lower guanidine concentrations, the inactivation rateconstants were only little affected whereas the denaturation rate constants decreased markedly,being of the order of 0.04 in 1 M and 0.004 in 0.5 M guanidine. The kinetics of the inactiva-tion reaction in 0.5 M guanidine was found to be in agreement with a combination of two firstorder reactions. The enzyme lost activity first by a fast reaction with a rate constant onlyslightly lower than the rate constant in 3 M guanidine followed by a slower reaction with a rateconstant of 0.003 sec~(-1). In 0.3 M guanidine, very little change in either UV absorbance or influorescence was observed, but, in sharp contrast, the enzyme lost considerable activity by a fastreaction and this was followed by a slower reaction of inactivation. Even after prolongeddenaturation in 0.5 and 0.3 M guanidine, residual activities of 3.4% and 30% remained res-pectively. The above results suggest a very fragile active site although dissociation of thedimer and reversible guanidine inhibition may also contribute to the initial rapid inactiva-tion. It is also to be noted that the multiphasic courses of inactivation at lower guanidineconcentrations seem to suggest the presence of partly active intermediates during denaturation.     

SURFACE OF GELATIN MODIFIED POLY(L-LACTIC ACID)FILM

In this paper, the surface structure of poly(L-lactic acid) (PLLA) film modified with gelatin was investigated. ThePLLA film specimens were treated directly with aqueous alkali solution to provide their surfaces with carboxyl groups, sothat these functional groups could become the reactive sites for gelatin immobilization. The functional groups of the PLLAfilms were identified by ATR-FTIR spectra and XPS spectra, the changes in surface morphology were observed by usingenvironmental scanning electron microscopy (ESEM), and the hydrophilicity of modified PLLA films was examined bywater contact angle measurement. Experimental results showed that the gelatin was immobilized with water-solublecarbodiimide (EDC) onto the PLLA film's surfaces, and the gelatin content on the polymer surface was related to carboxylicgroup formed in the controlled hydrolysis process. Rough surfaces caused by hydrolysis will predominantly favor the adhesion and growth of cell; and the hydrophilicity of these surfaces after the modification procedure is enhanced.