耐高温复合薄膜用聚氨酯胶粘剂的研究

介绍以芳烃聚酯多醇为主体的双组份 ,干式复合用聚氨酯胶粘剂的合成方法及其性能。讨论了己二酸 苯酐配比及反应温度、时间对合成芳烃聚酯及胶粘剂性能的影响。     

An efficient one-pot synthesis of tetrahydrothiazolo[3,2-a]quinolin-6-one derivatives

The cysteamine hydrochloride as a practical precursor of 2-(nitromethylene)thiazolidine in the one-pot synthesis of thiazoloquinoline derivatives from aromatic aldehydes and dimedone is described. This protocol involved Michael reaction, imine–enamine tautomerization, and cyclization sequence. Simple operation under mild conditions, easy accessibility of reactants, short reaction times, simple workup procedure, high atom economy, and the use of ethanol/water as a green medium make this approach attractive for the synthesis of variety of such derivatives.     

Preparation of thermosensitive microcapsules and application on the controllable drug delivery of ibuprofen

To reduce the side effects of ibuprofen caused by prolonged or overdosed treatment on the human body, a series of thermosensitive poly(N,N′-methylene bisacrylamide-co-N-isopropylacrylamide) microcapsules were synthesized to control the release of ibuprofen by their thermosensitive properties. The release curves exhibited excellent controllable behavior, which turned from burst release to perfect sustained release by changing the ambient temperature from 25°C (<LCST, lower critical solution temperatures) to 37°C (>LCST). In addition, the NIPAm content and the shell thickness can be conveniently controlled during the polymerization processes, which will affect the drug release rate according to the temperature stimuli.     

Trigonal Prismatic Cu6L3 Coordination Cage: Encapsulation of Aromatic Molecules and Tuned Photoluminescence

A trigonal prismatic Cu₆L₃ coordination cage has been assembled from Cu(I) and semi‐rigid bipyrazolyl ligand. The X‐ray crystallography demonstrates that the cage has a cavity and can encapsulate the toluene as a guest, exhibiting thermochromism phenomenon. Empty cage can be obtained by expulsion of the guest through single crystal to single crystal transformation. After removed the guest, the empty cage shows a blue‐shifted emission (580 nm), in comparison to its parent cage (615 nm). The empty cage could further serve as a host to encapsulate other aromatic molecules (e. g. mesitylene), which shows new emission band. The trigonal prismatic Cu₆L₃ coordination cage provides a platform to make advanced luminescent materials.     

Levels of Polycyclic Aromatic Hydrocarbons (PAHs) in Atmospheric Environment of Urban Areas in Latin America

Polycyclic aromatic hydrocarbons (PAHs) are chemical compounds considered as pollutants of high priority due to their carcinogenic potential. PAH can appear in water, soil or in the atmosphere as adsorbed on particulate material or in gas phase. An increased number of studies on atmospheric PAH in urban areas have been published in the last decade, especially in the last years. Anthropogenic sources are frequently mentioned to be responsible for the increased concentration of PAHs in the atmosphere of urban areas, which at the same time seems to depend on meteorological parameters. This research is focused on compiling information on PAH levels in Latin America and their relationship with typical meteorological variables from seasonal and tropical countries. Brazil is the country with the most number of bibliographies about this topic, followed by Argentina, Chile and Mexico. Scarce information was found for Colombia and Venezuela and none for the rest of Latin American countries. The majority of studies checked have evaluated the climatological parameters in relationship with the PAH concentration and their distribution, finding that it affects meaningfully their levels. The monitor campaigns in Brazil have been developed mainly in the southern cities, where PAHs are strongly influenced by the seasons and their proximity to the South Pole. Tropical countries such as Venezuela and Colombia showed moderate variation of PAH concentration through months. The main influential parameters are precipitation and direction/speed winds.     

浓香型白酒酒醅中化学物质的变化及其规律性

为建立浓香型白酒窖池资源数据库，论文采用白酒行业实用分析方法，对酒醅不同空间位置水分、酸度、还原糖、粗淀粉、乙醇等多项指标进行了动态跟踪分析。实验发现，发酵过程中水分含量呈上升趋势，上层酒醅水分饱和后保持在63％左右；产酸期后酒醅pH值缓慢下降至约pH3．2，酒醅的总酸共升高40度左右；酒醅的粗淀粉下降至27d后趋于平衡，还原糖则表现为波动式下降；主发酵结束后，3层酒醅的乙醇浓度均达到5．2％～5．5％的较高水平。结果表明，发酵过程中化学物质的代谢变化具有较明显的规律性，且随微生物类群的生长变化而波动，代谢曲线可为白酒发酵过程在线监控及窖池微生态的人工模拟提供有效数据。     

脉冲放电降解垃圾焚烧飞灰PAHs和二恶英的研究

焚烧炉处理城市垃圾后排放的粉尘中含有严重危害人类身体健康，甚至危害生命安全的有机污染物多环芳烃(PAHs)和二恶英。该文采用高压正脉冲电晕放电低温等离子体对垃圾焚烧炉布袋除尘器中飞灰进行处理，并对处理后飞灰的孔隙结构、微观表面形态及其PAHs和二恶英含量进行了观察分析。结果发现高压正脉冲电晕放电可以使颗粒表面产生物理脆性变化，从而改变其原有的孔隙结构。含量分析结果表明放电后粉尘中PAHs和二恶英含量明显降低，而且随着放电峰值电压升高，降解效率逐渐增加。随着粉尘中PAHs和二恶英初始浓度的增加，降解效率有所减小，峰值电压为30 kV时对高浓度二恶英的降解效率为5%~15%，对低浓度二恶英的降解效率可以高达50%。随着放电时间的增加，PAHs的降解效率逐渐增加，放电时间3 min对其降解效率可达80%。     

吉林市哈达湾工业区大气气溶胶中萘和联苯的污染特征

大气气溶胶中的多环芳烃是对人体健康危害最大的环境污染物之一.对2003年至2004年在吉林市哈达湾和江南公园采集的31个大气气溶胶样品,采用超声波萃取法提取其中的多环芳烃,对其进行浓缩和层析,用高效液相色谱法对其中的萘和联苯进行定量分析.得到哈达湾采样点萘和联苯的浓度均高于江南公园采样点萘和联苯的浓度.     

在线测量模拟烟气中苊和三氯苯的试验研究

为了获得一种可用于在线获得燃烧烟气中二噁英浓度的方法，采用飞行时间质谱仪对模拟烟气中的多环芳烃－苊和二噁英前驱物－三氯苯进行了在线测量试验。研究结果显示，飞行时间质谱仪对烟气中苊的测量具有良好的响应性能，在线检测信号强度与离线分析结果具有较好的相关性；将烟气中苊的离线测量结果和在线测量结果进行了拟和，初步实现了苊在线测量的质量标定。应用上述方法对二噁英前驱物－三氯苯的在线测量结果表明，飞行时间质谱仪对烟气中三氯酚进行测量时的响应性能很好，干扰也较少.试验结果说明,实际烟气中苊、三氯苯等有机物的在线检测完全有可能实现，这对研究二噁英类痕量有机污染物的在线检测方法提供了参考.     

模拟烟气中痕量有机污染物生成的在线实时监测

多环芳烃和二恶英是两类剧毒的持久性有机污染物,为了研究其生成和排放过程，需要开发一种能用于烟气的实时检测方法。该文采用高分辨力的真空紫外光电离/微型正交加速型电离飞行时间质谱仪(VUV-TOF-MS)，对由聚氯乙烯(PVC)在氮气流中热解形成的模拟烟气中多环芳烃和二恶英的前驱物进行了实时在线检测。然后和离线方法的分析结果进行对比，给出了烟气中多环芳烃和二恶英前驱物的实时浓度曲线。再根据三氯苯和二恶英的转化率，估算出二恶英的在线浓度范围。同时根据对烟气中多环芳烃和二恶英前驱物的时间行为特征的研究，讨论了PVC热解时多环芳烃和二恶英前驱物的发生机理和成长途径。