聚碳酸亚丙酯/淀粉在城市垃圾中生物降解性能研究

将聚碳酸亚丙酯新型高分子材料与淀粉进行共混, 研究了共混物的机械性能及其在城市垃圾中的生物降解过程.结果表明, 淀粉的加入可提高材料的拉伸强度和拉伸模量, 促进聚碳酸亚丙酯的微生物降解速度. 降解实验显示半年降解样出现大量空洞, 共混物中聚碳酸亚丙酯的数均分子量下降40.5%,其降解可分为三个过程, 分别对应微生物的生长、淀粉的降解及PPC的降解. 红外测试表明半年降解样仍含有少量淀粉.     

山间盆地砂岩型铀矿成矿物质来源研究——以吐哈盆地和二连盆地为例

通过野外观察、镜下鉴定和锆石测年分析,研究吐哈盆地和二连盆地砂岩型铀矿的成矿物质来源。研究结果表明,吐哈盆地目的层锆石年龄主要集中在(440.9±2.3)Ma,其物源应为加里东期片麻状花岗岩侵入体,铀源主要来自于预富集。二连盆地物源主要来源于古河道上游和两侧岩体,铀源主要以岩体铀的风化淋滤为主,地层中火山碎屑岩也为铀的富集提供了补充。并在此基础上分析了山间盆地铀源条件对铀成矿的控制与影响。     

The Electrical Behaviour of Starch-based Polymer Electrolytes

1 Results Starch is a well-known,versatile,and inexpensive agricultural material used for a variety of industrial applications.In addition to being a major food item,it is currently used industrially as coatings and sizing in paper,textiles and carpets,as binders and adhesives,as absorbants,and as encapsulants[1].Starch is composed of repeating 1,4-α-D glucopyranosyl units: amylose and amylopectin[2].Due to its good mechanical properties,film forming ability as well as electrical conductivity[3],it offe...     

淀粉接枝丙烯酸制备高分子灭火剂

.以淀粉/丙烯酸为原料,用二乙烯苯为交联剂,过硫酸钾和亚硫酸氢钠为引发体系.经接枝共聚制备淀粉/丙烯酸高吸水性树脂,再由高吸水性树脂制取高分子灭火剂.本文分析了交联剂用量、引发体系配比、单体中和度以及淀粉与单体配比等因素对吸水率的影响,并考察了高分子灭火剂的灭火性能.实验证明高吸水性树脂可吸蒸馏水600g/g,用它配制的高分子灭火剂是自来水灭火效能的14倍.     

耐旱型种衣剂吸水性树脂研究

根据自由基聚合和接枝共聚合、交联反应的机理,用淀粉接枝共聚丙烯酰胺制得高吸水性树脂,并将其用于玉米等春播作物的耐旱型种衣剂。文中讨论了单体与淀粉配比、交联剂用量、引发剂用量、水解反应和氮气等因素对吸水树脂吸水性能的影响。     

乙烯-辛烯共聚物/淀粉共混物的非等温热解动力学

利用动态热重分析(TG)技术对乙烯-辛烯共聚物(POE)/糊化蜡质玉米淀粉(GWCS)共混物在惰性气体条件下的热性能和非等温热解动力学进行了分析,探讨了其热解机理.结果表明,随着淀粉含量的增加,POE/GWCS共混物的热失重曲线向低温方向移动,材料的外延起始温度降低,即材料的热稳定性降低,说明淀粉的加入降低了聚合物的耐热性能.随着升温速率的增加,POE/GWCS共混物最大热分解速率对应的温度向高温方向移动,最大热分解速率增大.采用Kissinger和Flynn-Wall-Ozawa两种方法进行热解动力学分析,发现随着淀粉含量增加,共混物体系的热分解E/logA值降低,表明淀粉含量对共混物的热稳定性有显著影响.     

淀粉-丙烯酸-丙烯酰胺三元接枝共聚物的合成及吸水性能研究

以淀粉为主要原料,丙烯酰胺、丙烯酸为接枝单体,采用反相乳液聚合方法合成了改性淀粉三元接枝共聚物;考察了交联剂、引发剂浓度、单体配比、中和度、反应温度等因素对淀粉-丙烯酸-丙烯酰胺三元接枝共聚物吸水性能的影响.实验结果显示,采用反相乳液聚合方法能得到具有高吸水率的淀粉接枝共聚物;且反应温度、引发剂浓度、交联剂浓度和单体配比、中和度等因素对淀粉三元接枝产物吸水性能有显著的影响,其最佳反应条件为:交联剂浓度1.2×10-3kg.L-1;引发剂浓度6×10-3kg.L-1;丙烯酰胺/丙烯酸=0.11;中和度75%.     

滇池流域大棚种植区面源污染模拟

相对于传统的露天种植,塑料大棚改变了降雨径流和土壤侵蚀过程,进而影响面源污染物的产生。为定量研究滇池流域大棚种植区的面源污染负荷情况,选择滇池东岸某示范区为研究对象,利用清华大学开发的IMPULSE模型对其暴雨径流过程进行模拟研究,估算大棚种植区的污染负荷,总结出大棚种植区暴雨径流和面源污染的基本特征。研究表明,塑料大棚有增加地表径流量和减少地表侵蚀和面源污染两方面的作用。     

生物基表面活性剂——烷基糖苷的发展现状

生物基表面活性剂--烷基糖苷(APG),是以可再生资源如淀粉和天然脂肪醇等为原料制得的新一代温和型"绿色"非离子表面活性剂,对于烷基糖苷的研究已成为表面活性剂领域的热点问题.因此,对烷基糖苷的国内外发展现状、合成机理、合成方法、影响因素及其应用等进行了评述.烷基糖苷的合成技术正朝着高效、低成本的方向发展;应用方面以其优良的表面活性和生物降解等物化性能被广泛用于日化等领域,对烷基糖苷的深入研究将对表面活性剂市场产生深远的影响.     

Sources and transportation of suspended matter and sediment in the southern Yellow Sea: Evidence from stable carbon isotopes

The concentrations of total suspended matter (TSM) and the compositions of organic stable carbon iso- topes of TSM and bottom sediments were analyzed to study the sources of TSM and sediments and the transportation processes. For this study, 284 TSM samples and 64 sediment ones taken from 67 stations along 7 transects and in 5 layers were collected in the southern Yellow Sea on the cruise in May, 1998. The main sediment transportation pattern in the southern Yellow Sea was obtained by analyzing the distribu- tion characteristics of TSM concentration and particulate organic carbon δ~(13)C values. It was confirmed from the pat- tern that the bottom layer plays a more important role than the surface one in the transportation processes of terrigenous material to the central deep-water area of the southern Yel- low Sea. The Yellow Sea circulation is an important control factor in determining the sediment transportation pattern in the southern Yellow Sea, The carbon isotope signals of sedi- mentary organic matter confirmed that the main material in sediments with high sedimentation rate in the Shandong subaqueous delta originated from the modern Yellow River. The terrigenous sediments in the deep-water area of the southern Yellow Sea are mainly from the abandoned Yellow River and the modern Yellow River, and a small portion of them are from the modern Yangtze material. The amount of terrigenous material from Korean Peninsula and its influen- ce range are relatively limited. The conclusions derived from TSM and stable carbon isotopes were further confirmed by another independent material source tracer-PAHs.