聚3,4-乙撑二氧噻吩在乙醇中分散体的制备与应用

近几年来,有机导电杂环类聚合物引起了科学家们的广泛注意,而一种新型导电聚合物聚噻吩衍生物聚3,4-乙撑二氧噻吩(PEDOT)更成为研究的热点。目前,合成PEDOT的方法主要有化学氧化聚合[5-8]、电化学聚合、化学气相沉积法等,其中应用最多的是化学氧化聚合法,该方法设备简单,且易于聚合。     

转基因细菌吃废物造“汽油”

"吃"的是农业废料,"排泄"的是燃料!这不是科幻小说中的美好设想.美国科学家培植出一种转基因细菌,通过发酵,这种细菌可分泌出生物燃料.     

用于乙醇-水分离的SA-PVA/PSF中空纤维渗透汽化复合膜

Using polysulfone (PSF) hollow fiber ultrafiltration membranes as the substrate, sodium alginate (SA) and poly-vinyl alcohol (PVA) blend solutions as the coating solution, and maleic anhydride (MAC) as the cross-linked agent, SA-PVA/PSF hollow fiber composite membranes were prepared for the dehydration of ethanol-water. The effects of differentsodium alginate concentration in the coating solutions and different operating temperatures on pervaporation performance wereinvestigated. The experimental results showed that pervaporation performance of the SA-PVA/PSF composite membranesfor ethanol-water solution exhibited a high separation factor although they had a relatively low permeation flux. As SAconcentration in SA-PVA coating solution was 66.7% and the operating temperature was 40 C, SA-PVA/PSF hollow fibercomposite membrane (PS4) had a separation factor of 886 and flux of 12.6 g/(m2.h). Besides, SA-PVA/PSF hollow fibercomposite membranes (PS3 and PS4) were used for the investigation of the effect of ethanol concentration in the feed solutionon pervaporation performance.     

用于乙醇-水分离的SA-PVA/PSF中空纤维渗透汽化复合膜

Using polysulfone (PSF) hollow fiber ultrafiltration membranes as the substrate, sodium alginate (SA) and polyvinyl alcohol (PVA) blend solutions as the coating solution, and maleic anhydride (MAC) as the cross-linked agent, SAPVA/PSF hollow fiber composite membranes were prepared for the dehydration of ethanol-water. The effects of different sodium alginate concentration in the coating solutions and different operating temperatures on pervaporation performance were investigated. The experimental results showed that pervaporation performance of the SA-PVA/PSF composite membranes for ethanol-water solution exhibited a high separation factor although they had a relatively low permeation flux. As SA concentration in SA-PVA coating solution was 66.7% and the operating temperature was 40 ℃, SA-PVA/PSF hollow fiber composite membrane (PS4) had a separation factor of 886 and flux of 12.6 g/(m2·h). Besides, SA-PVA/PSF hollow fiber composite membranes (PS3 and PS4) were used for the investigation of the effect of ethanol concentration in the feed solution on pervaporation performance.     

纤维质燃料填充床正向阴燃传播特性的数值模拟

Based on a three-step kinetic mechanism, a one-dimensional, time dependent, numerical model is presented forthe smoldering propagation in a horizontally packed bed of cellulosic material. The kinetic processes include pyrolysis andoxidation degradation of fuel and oxidation of char. Heat transfer between solid and gas is taken into account, and the diffusioncoefficient varies with the temperature. Radiative heat transfer is included by using the diffusion approximation. The effectsof airflow velocity and oxygen concentration are simulated on the smoldering velocity and the averaged maximum temperatureof smoldering fuel. The results indicate that the spread rate varies linearly with increasing airflow velocity, and the inlet airvelocity has little effect on the maximum temperature. The evolutions of gas species and solid compositions are predicted.The effects of frequency factors (A1, A2 and A3) are analyzed. Simulations show that the smoldering spread rate increaseswith increasing A2 (fuel oxidation), but decreases with A1 (fuel pyrolysis) and A3 (char oxidation).     

美国学生开始过“苦日子”

低迷的经济和燃料价格攀高已开始对美国学生造成冲击。美国校车今年燃料成本可能会是将近去年的两倍,学校的空调、暖气、自助餐厅食物、教室用品等成本都不断上升。学生们需花更多的钱买午餐,用二和课本。学生家长也想办法省钱,除了减少支出,大多数家长都削减了孩子的上学置装费,减少购买新鞋和新书包。     

厨房灶具改革的重大突破——森海牌燃煤节能灶风靡上市使用3-6个月节约燃料的费用可以收回投资

煤炭石油是重要的战略物资,是不可再生的资源,随着社会经济的飞速发展,供求矛盾更加突出,节约能源,降低成本,是我们大家的责任。在此背景下,我厂科研人员经过多年倾心研究,开发的森海牌燃煤节能灶具已定型批量投放市场,该系列灶具已获得国家专利,并由中国人民保险公司负责质量承保。     

校园文学月报

点击文学社福建安溪恒兴中学进取文学社进取文学社创办于2002年12月,现有社员556人。文学社自成立以来,取得丰硕成果。社员作品在全国各报刊发表一百四十多篇;参加县级以上各类征文、作文比赛活动,获奖三百多人次。进取文学社获得2004年福建省第十一届青少年爱国主义教育读书活动优秀组织奖,在2005年全国优秀文学社评比中获得金奖。2008年2月,《德育报》、全国校报校刊联谊会授予进取文学社为全国校报校刊联谊会2007年度优秀理事单位。《进取》校刊主编苏立仁老师被《创新作文》《初中生优秀作文》聘为特约编辑。进取文学社将秉承"励志勤学,锐意进取"的宗旨,为全国校园文学缤纷的百花园绽放一缕芳香。     

透视奥运火炬燃料

自3月开始,2008年北京奥运会的星火在国内外多个城市进行了传递活动．传递了中国这个古老民族爱好和平、期待振兴的梦想。你可知道,现代奥林匹克火炬的传遂是从哪一届奥运会开始的？当时的火炬是什么样的？     

微波促纤维素水解制备可发酵还原糖研究

利用生物质纤维素生产燃料乙醇是目前研究的热点,而生物质纤维素乙醇转化技术的关键是如何将纤维素水解为可发酵还原糖.本文对常规加热法与微波幅射法水解纤维素制取还原糖进行了对比研究.实验结果表明,在微波辐射条件下,不仅能获得更高的还原糖收率,糖化时间更是大为缩短,极大地降低了水解过程能耗.