低分子量壳聚糖制备与应用研究进展

低分子量壳聚糖因具有特殊的生物活性而日益受到人们的关注。本文概要介绍了近5年来国内外低分子量壳聚糖的研究进展,包括低分子量壳聚糖的制备方法,如酶降解法、酸水解法、氧化降解法、物理法等,以及低分子量壳聚糖在农业、医药、抗菌、化妆品、食品等方面的应用。     

Glucose-lowering A ivity of Amino Acid- phosphonic Acid Oxovanadium Complexes and Its Interaction with DNA

Vanadium has well-documented lowering glucose properties both in vitro and in vivo. The design of new oxovanadium（IV） coordination compounds, intended for use as insulin-enhancing agents in the treatment of diabetes mellitus, can potentially benefit from a synergistic approach, in which the whole complex has more than an additive effect from its component parts. Biological testing with oxovanadium（IV） organic phosphonic acid, for insulin-enhancing potential included acute administration, by oral gavage in streptozotocin （STZ） diabetic rats. The complexes of oxovanadium（IV） amino acid-N-phosphonic acid exhibit higher lowering glucose activity in vivo. The interaction of the complexes of oxovanadium（IV） amino acid-N-phosphonic acid with DNA was investigated by agarose gel electrophoresis. The results indicated that these complexes have strong interaction with DNA.     

不同方法制备的Cu－Co低碳醇合成催化剂的比较研究Ⅰ．吸附态CO的红外光谱

本文并行考察了用溶剂化金属原子分散（ＳＭＡＤ）、浸渍、共沉淀三种方法制备的Ｃｕ－Ｃｏ催化剂的一氧化碳加氢反应（５６３Ｋ，６ＭＰａ，Ｈ２／ＣＯ＝２）性能及吸附态ＣＯ的红外光谱．结果表明：（１）三种催化剂上反应产物均为Ｃ１－Ｃ５正构醇及正构烃，总醇的选择性依下列次序递增：ＳＭＡＤ＜浸渍＜共沉淀；（２）表面低配位钻中心上多重吸附态ＣＯ的红外吸收峰的面积分数，对不同催化剂的变化规律，与醇选择性的变化一致；（３）高温还原和焙烧均使醇选择性下降，同时使表面低配位Ｃｏ０中心减少．据此讨论了ＣＯ插入中心，活性结构及制备方法的影响．     

Tb(III)与PNIPAM接枝核壳纳米微球相互作用的研究

利用透射电镜、X射线光电子能谱、动态激光光散射和荧光光谱技术对Tb(III)与聚N-异丙基丙烯酰胺(PNIPAM)接枝核壳纳米微球PNIPAM-g-P(NIPAM-co-St) (PNNS)的相互作用进行了研究. 结果表明: Tb(III)和热敏性的核壳纳米微球PNNS有显著的相互作用. 其一, Tb(III)可与PNNS中酰胺基团上的氧原子配位形成微球配合物Tb(III)-PNNS; 其二, Tb(III)-PNNS微球配合物兼具热敏性; 其三, 该配合物在545 nm处的荧光强度较Tb(III)增大了233倍, Tb(III)与PNNS分子间能量传递达到50%, 当Tb(III) 质量分数为12%时荧光强度最大.     

煤液化残渣与生物质混合燃烧过程中硫污染物动态排放特性研究

生物质在全球总能源消耗中占有相当大的比例，世界各国对生物质能利用新技术的研究日益重视。用生物质燃料替代传统的化石燃料，不仅可以缓解日益严重的能源问题，也可以减少环境污染和降低CO2的排放心。但生物质的热值比较低，单独利用效率较低，因此一些欧美发达国家采取了将部分生物质与煤混和燃烧发电或气化的新技术。     

Theoretical Study on Adsorption and Diffusion of N Atoms on Cu Low-index Surface

The adsorption and diffusion of N atoms on the three low-index Cu planes were studied using 5-parameter Morse potential (5-MP) method, and the best theory-experiment agreement was obtained. N atoms of Cu(100) surface sit on the fourfold hollow site with the vertical height of 0.018 nm closely coplanar with the topmost copper layer, and the four Cu-N bond lengths are 0.182 nm and the fifth Cu-N distance is 0.199 nm. For Cu(111) system, the existence of aberrant Cu(100) reconstructed structure is approved at higher coverage, and at low coverage the structure is almost an ideal Cu(111) surface structure. With respect to Cu(110) system, the N atoms are adsorbed at LB and H3 sites, not at SB site. The diffusion passage and diffusion barrier of adsorbed N atoms were also studied.     

稀土元素对低铬半钢热疲劳性能的影响

研究了稀土元素对低铬半钢铸态及经热处理后组织中的共晶碳化物形状的影响，在此基础上着重研究了该材料的热疲劳性能。结果表明：稀土元素能改善共晶碳化物的形状，抑制热疲劳裂纹的萌生与扩展，提高其热疲劳性能，尤其稀土变质后再经热处理后效果更明显。当试样经0.20%（质量分数）稀土变质后经950℃，3h正火处理时，热疲劳性能最佳。     

贵金属部分取代稀土钙钛矿B位在汽车排放中的应用

研究了以钙钛矿LaMnO3为基体的贵金属三效催化剂中两者的相互作用状况及对CO,NO的催化氧化还原反应.实验结果表明,由于贵金属和稀土氧化物的相互作用降低了CO,NO反应的起活温度.从微观结构探讨了贵金属与复合稀土氧化物之间的相互作用机理,并且认为贵金属对稀土钙钛矿结构中B位的部分取代是开发贵金属-稀土三效汽车尾气净化催化剂的重要理论基础.     

OBTAINING THE CRITICAL DRAW RATIO OF DRAW RESONANCE IN MELT SPINNING FOR POWER LAW POLYMER FLUIDS

A direct difference method has been developed for Non-Newtonian power law fluids to solve the simultaneous non-linear partial differential equations of melt spinning,and to determine the critical draw ratio for draw resonance.The results show that for shear thin fluids,the logarithm of the critical draw ratio has a well defined linear relationship with the power index for isothermal and uniform tension melt spinning.When the power index approaches zero,the critical draw ratio points at unity,indicating no melt spinning can be processed stably for such fluids.For shear thick fluids,the critical draw ratio increases in a more rapid way with increasing the power index.     

乙烯-丙烯共聚物磺酸盐离聚物的研究——Ⅱ.离聚物的合成和表征

通过氯磺化共聚物的水解合成了乙烯-丙烯共聚物磺酸钠离聚物,对离聚物的结晶度和其中硫、氯、钠元素的含量进行了表征.当离子含量达到5—7 mol％时,离聚物的LAXD曲线出现离子峰;DSC指出T_g急剧升高,而低于此离子浓度的离聚物均不出现这些现象.反映出此离子浓度下的离聚物,离子基因可能聚集形成离子簇结构.