尿液中甲苯二异氰酸酯及其代谢产物的高效液相色谱法测定

用高效液相色谱法直接测定尿液中的甲苯二胺和甲苯二异氰酸酯，有效评价TDI在体内的代谢及残留。该方法操作简便、快捷，无需特殊试剂和设备。     

Does complex hydrology require complex water quality policy?

Nonpoint‐source water pollution is frequently considered intractable because it is hard to regulate large numbers of small sources and because the science associated with assessing the impact of each source is complex. New Zealand has demonstrated that it is possible to implement a simple cap‐and‐trade system to help reduce nitrogen leaching from many small farms and thereby protect water quality. This paper relates to the second challenge: are complex regulatory systems worthwhile when nitrogen delivery is complex? When nitrogen moves through groundwater to a lake, leaching from different farms reaches the lake at different times and the damage caused is temporally differentiated. Policy that regulates farmers according to the timing of their nitrogen delivery will be more complex than policy that does not. Whether the gain in efficiency justifies this additional complexity can be assessed through modelling. We use an integrated model to estimate the gains from complex nitrogen regulation that incorporates groundwater delivery times relative to simple nitrogen regulation that does not. We find that the gains from more complex regulation are small in the catchment we study and cannot justify the additional complexity required. A sensitivity analysis enables us to identify the types of catchments where complex regulation may be worthwhile.     

用于立体显示的可变焦距液晶透镜

基于像素分割控制的立体显示技术可使观众在欣赏立体影像时摆脱眼镜的束缚。本文所述的立体显示装置利用多电极驱动液晶透镜方式可以实现多个立体显示的观看距离。利用电压的改变最佳的观看距离可以在45cm到80cm之间调节。     

高效液相色谱法测定北虫草酒中的北虫草素

采用高效液相色谱法建立了虫草酒中虫草素含量的测定方法,探讨了色谱柱类型、流动相组成、柱温以及检测波长对分析结果的影响。研究表明:当色谱柱为WondaSilTM C18柱(150mm×4.6mm i.d.,5μm);流动相为乙腈-水(体积比为10:90),流速为1ml/min;检测波长258nm;柱温40℃;进样量5μl时分离、检测效果最佳,此法操作简便,样品只需用0.45μm微孔滤膜过滤处理,线性范围宽、重现性好、精密度高,效果令人满意,对于虫草酒的生产和质量检测都具有现实的指导意义。     

液体化工品运输新方式──集装罐运输

介绍液体化工品运输的一种新方式──集装罐运输，主要介绍集装罐运输的优点，集装罐运输的应用范围，集装罐租赁业，世界主要集装罐经营者，全球集装罐运输形势，集装罐运输的前景等。     

质子化吡咯烷表面活性剂的有序聚集行为

合成了一系列不同链长的质子化吡咯烷类表面活性剂，通过核磁共振和差示扫描量热法进行了结构和热分析，进一步结合变温偏光显微镜进行分析，结果表明，此类化合物通过升温可以形成排列有序的T相热致液晶，形成温度随链长的增加逐渐升高。此类化合物还可以在水中形成胶束，临界胶束浓度随着表面活性剂链长的增加逐渐降低，继续升高表面活性剂浓度，可以形成溶致液晶。     

基于流动性风险理论的国有股过渡流通市场方案

从流动性风险角度研究非流通股，认为国有股的历次减持巨幅冲击A股市场的情况是国有股本身存在的流动性风险的市场表现，因此非流通股本身存在流动性风险，也就是相对于，A股市场的规模与现有运行机制而言，非流通股本身就不具有那么高的流动性，如果强行给予非流通股t＋1的流动性，则A股市场将被冲垮。国有股减持政策的设计应当顺应非流通股流动性风险的本性，顺应非流通股相对于现有A股不具有流通性的本性，以t＋X制度缓解非流通股转流通对A股市场的冲击和给A股市场造成的流动性风险。而且还能促进我国形成一定程度的公司控制权市场。     

高效液相色谱法测定蔬菜中磺酰脲类除草剂多残留量的研究

【目的】建立高效液相色谱法同时测定蔬菜中8种磺酰脲类除草剂残留量的检测方法。防法】样品经乙腈提取、凝胶渗透色谱净化、C18固相萃取柱净化后,采用高效液相色谱分离,二极管阵列检测器检测,外标法定量。【结果】8种磺酰脲类除草剂在0．1～10μg/mL范围内线性关系良好,相关系数为0．9998-0．9999。在0．02～0．5mg／kg添加浓度范围内,平均回收率在72．2％-100．4％之间,相对标准偏差为1．0％～9．5％。[结论]本法简便、快速、定量准确、精密度高,适用于进出口蔬菜中多种磺酰脲类除草剂残留量的同时检测。     

International Versus National Actions Against Nitrogen Pollution of the Baltic Sea

Large nitrogen loads to the Baltic Sea play an important role for currentdamages caused by eutrophication: large sea bottom areas without anybiological life, low stocks of cods, and toxic blue green algae. In spite of therelatively large supply of biological and physical data on the sea,difficulties remain with respect to linking costs of nitrogen reductions withthe dispersion of associated benefits among countries. The purpose of thisstudy is therefore to analyse and calculate efficient nitrogen reductionsand associated net benefits under international co-ordination of nitrogenreductions and single country actions for two different specifications ofmarginal benefits: uniform and differentiated. Further, comparisons aremade with the current ministerial agreement of 50 per cent nitrogenreduction to the Baltic Sea. The empirical results show that total netbenefits under internationally co-ordinated actions are considerablyhigher than when countries act on their own. Another result is thatdifferentiated benefits give higher total net benefits than uniform, and alsoimply larger differences in net benefits among countries. However, resultsindicate that uniform marginal benefits generate net benefits for allcountries from co-ordinated actions as compared to single country actions.     

高效液相色谱法测定辣椒油中苏丹红的含量

本文对国家标准《食品中苏丹红染料的检测方法高效液相色谱法》(GB/T 19681-2005)中利用高效液相色谱法测定辣椒油中苏丹红含量的方法进行优化,使方法更加简便快捷,且满足实验要求。以正己烷为提取溶剂,提取液经ProElut SDH固相萃取柱净化,经高效液相色谱柱分离,外标法定量。优化后的方法中,苏丹红Ⅰ~Ⅳ在0.16~2.56μg/mL的浓度范围内线性关系良好,苏丹红Ⅰ~Ⅳ的检出限分别为0.010 7μg/kg、0.011 1μg/kg、0.011 9μg/kg、0.011 0μg/kg,加标回收率为89.21%~95.69%。优化后的实验方法易于操作,能够缩短实验时间,有良好的回收率,更适合检测辣椒油中苏丹红的含量。