偕二硝基乙酸乙酯的合成与表征

以丙二酸二乙酯为起始原料,经水解、脱羧氧化硝化得到标题化合物,并利用红外光谱、核磁共振、质谱等鉴定其结构;初步探讨了脱羧氧化硝化反应历程,优化了反应条件;对二硝基乙酸乙酯合成方法进行了重大改进,发现以NaNO2-98%工业硝酸为硝化剂,具有原料易得、操作简便、收率较高(>65%)、粗品纯度较高(>93%)的优点.     

可见光响应Fe掺杂ZnO/凹凸棒石复合材料的制备和光催化性能

采用直接沉淀法制备了Fe掺杂ZnO/凹凸棒石(Fe-ZnO/ATP)复合材料,评价了其在可见光条件下(＞400 nm)光催化降解高浓度亚甲基蓝(MB)溶液的性能,并系统研究了ZnO负载量、Fe掺杂量和焙烧温度等对复合材料吸附性能和光催化性能的影响.结果表明,ATP的复合增强了复合材料对MB的吸附能力,MB在最佳条件下制备的Fe(0.3％)-ZnO(50％)/ATP复合材料上降解的表观反应速率常数(kapp)为4.2×10-3 min-1,反应3.5h后的降解率可达65.40％,与ZnO相比较,kapp和MB的降解率提高了2.6倍.XRD、TEM和UV-Vis-DRS的结果表明,复合材料中ATP的结构在热处理过程中基本保持不变,复合材料中ZnO的粒径明显减小,暴露了更多的活性位点.另外,Fe的掺杂可明显增强复合光催化剂对可见光的吸收,增强了对光的利用效率,从而使复合材料显示出优异的光催化活性.     

电化学氧化还原法降解卤代有机污染物的研究进展

卤代有机污染物的降解是水污染控制的一项重要课题.在诸多的降解技术中,电化学降解法具备反应条件温和、反应器简单、设备及其运行成本低、毒性副产物少等优点,因而成为一项极具发展前景的环境友好型应用技术.综述了电化学氧化还原降解的反应机理以及目前国内外学者对该技术的研究进展,同时指出该技术研究在实际应用中所存在的问题和不足,并对未来电化学氧化降解卤代有机污染物的技术研究进行了展望.     

Large-area photovoltaics based on low band gap copolymers of thiophene and benzothiadiazole or benzo-bis(thiadiazole)

Large-area solar cells (active area=3 and 10 cm²) were prepared with low band gap polymers based on thiophene and benzothiadiazole (1) or thiophene and benzo-bis(thiadiazole) (2). The band gaps of the polymers were 1.65 and 0.67 eV, respectively. The best photovoltaic performance was obtained for the device ITO/PEDOT/1:PCBM (1:2)/Al with an active area of 3 cm². The efficiency of the device was 0.62%. This is a high efficiency for a low band gap polymer in a large-area organic solar cell and thus polymer 1 is a very promising material for organic solar cells. The devices based on 2 were found to give poor devices when employed in bulk heterojunctions with PCBM. This was linked to a poor alignment of the energy levels in 2 with that of the electrodes and PCBM, showing that the requirement for a control of the positions of the energy levels becomes increasingly important as the band gap decreases.     

Evidence for mineral matter forms in coal liquefaction extracts

High- and low-temperature ashes from feed coal, coal extract solution and filter cake from a two-stage coal liquefaction process have been studied by X-ray diffraction (XRD) and scanning electron microscopy/energy dispersive X-ray fluorescence (SEM/EDX). Hydrocracking experiments using alumina support only, in place of the active Ni/Mo catalyst on alumina, were also carried out, with trace metal analysis of the coal extract solution feed and hydrocracked extracts using atomic absorption and emission spectroscopy. The major mineral transformations occurring were of pyrite to pyrrhotite and the fixation of organic sulphur by calcium carbonate. Mineral particles were not observed in the coal extract solution ashes, even under high magnification, and the study indicated that size alone was not a determining factor as to whether a coal mineral was to be found in a coal-derived liquid. None of the trace metals was deposited on the alumina support under hydrocracking conditions, in marked contrast to the results obtained with the normal Ni/Mo catalyst. These results lead to the conclusion that for the deposition of trace elements to occur a reaction must take place and hence the trace elements must be chemically bound in some form.     

PLA/PBAu嵌段共聚物合成工艺优化及降解性能

以端羟基聚乳酸（PLA）、聚己二酸-丁二醇-尿素（PBAu）为预聚物,六亚甲基二异氰酸酯（HDI）为扩链剂,制备出一种新型PLA/PBAu嵌段共聚物。研究了扩链剂用量、扩链温度以及催化剂用量对PLA/PBAu嵌段共聚物分子量的影响,确定了合成PLA/PBAu嵌段共聚物的最佳工艺条件。采用核磁共振、凝胶渗透色谱、差示扫描量热仪、扫描电镜等对共聚物薄膜结构及性能进行表征。结果表明：成功合成了PLA/PBAu嵌段共聚物,分子量可达10×10⁴,玻璃化转变温度约为41℃;并且随着PBAu含量的增加,共聚物的结晶度逐渐增加。以NaOH溶液为模拟液进行加速降解实验发现,当PBAu含量为30%时,可以显著提高嵌段共聚物的降解速率,并且通过调节PLA、PBAu预聚物的含量,可以控制嵌段共聚物的降解速率。     

挥发性有机物的治理以及活性炭的应用研究进展

从挥发性有机物(VOCs)的基本概念出发,介绍了其分类、来源、污染现状以及其对人体的危害,并在此基础上具体地介绍了目前处理挥发性有机物的基本方法,比如吸收技术、冷凝技术、膜基技术、燃烧技术、生物净化技术等。同时探讨了活性炭在治理VOCs方面作为吸附剂和光催化剂载体等方面的应用。从而提出了活性炭在VOCs治理方面的急需解决的问题以及发展趋势。     

氧化铝、氮化硅和碳化硅的疲劳特性与寿命预测

分析了几种典型的结构陶瓷在长期载荷下的失效特性和差别。认为长期失效的本质是强度衰减,建立了一个疲劳失效的强度衰减模型和提出了寿命预测方法。分别研究了氧化铝、氮化硅和碳化硅几种常用工程陶瓷在常温和高温下的疲劳特性和差异。采用三点弯曲的受力方式测试了不同载荷水平下的断裂时间。结果表明：碳化硅的疲劳门榄值超过强度的80％,而且受温度影响最小;氧化铝的静疲劳受微小裂纹扩展控制;氮化硅的高温疲劳主要是蠕变机制导致强度衰减,疲劳门槛值不超过强度50％。由实验研究了氮化硅的高温静疲劳、动疲劳和循环疲劳三者在相同温度和相同应力峰值变化下的寿命关系,结果与计算一致。     

有机固体废弃物在固定床内热解的实验研究

通过对几种典型的城市有机固体废弃物的热解实验，为开展新的垃圾处理工艺提供基础研究。文中考察了不同工况下的有机固体废弃物的热解产物特性，分析了物料性质、热解终温、加热方式等因素对热解产物分布的影响。通过实验发现，热解终温是较重要的影响因素，同时物料的工业分析结果也是一个重要因素。     

奥里油特性及其发电应用分析

针对我国即将成为奥里油的重要用户这一客观形势，介绍了奥里油的特性及其在电厂中应用的优缺点，并指出了在应用中须注意的几个技术问题，最后介绍了奥里油燃烧后烟气的净化和废物的处理问题。