Passive sampling and/or extraction techniques in environmental analysis: a review

The current state-of-the-art of passive sampling and/or extraction methods for long-term monitoring of pollutants in different environmental compartments is discussed in this review. Passive dosimeters that have been successfully used to monitor organic and inorganic contaminants in air, water, sediments, and soil are presented. The application of new approaches to the determination of pollutants at the sampling stage is discussed. The main milestones in the development of passive techniques for sampling and/or extraction of analytes, and in biomonitors used in environmental analysis, are summarized in this review. Passive samplers and biomonitors are compared.     

TiNi合金表面原位热氧化膜的结构与光电性能的研究

采用AFM、XRD和EDS等手段,对TiNi合金在空气中、400—800℃下形成的氧化膜组织结构进行了分析,并对TiNi合金表面原位热氧化膜的光电性能进行了研究.结果表明,TiNi合金在空气中氧化原位形成的氧化膜的结构主要为金红石型二氧化钛,不同温度下生长的氧化膜存在择优取向;随着氧化温度的升高,所制备的TiO2/TiNi电极的稳态光电流和开路光电压随氧化温度的升高先增大后减小,在700℃所制备的TiO2/TiNi电极的稳态光电流最大.     

Virtual screening of novel noncovalent inhibitors for SARS-CoV 3C-like proteinase

The SARS coronavirus 3C-like proteinase is considered as a potential drug design target for the treatment of severe acute respiratory syndrome (SARS). Owing to the lack of available drugs for the treatment of SARS, the discovery of inhibitors for SARS coronavirus 3C-like proteinase that can potentially be optimized as drugs appears to be highly desirable. We have built a "flexible" three-dimensional model for SARS 3C-like proteinase by homology modeling and multicanonical molecular dynamics method and used the model for virtual screening of chemical databases. After Dock procedures, strategies including pharmocophore model, consensus scoring, and "drug-like" filters were applied in order to accelerate the process and improve the success rate of virtual docking screening hit lists. Forty compounds were purchased and tested by HPLC and colorimetric assay against SARS 3C-like proteinase. Three of them including calmidazolium, a well-known antagonist of calmodulin, were found to inhibit the enzyme with an apparent K(i) from 61 to 178 microM. These active compounds and their binding modes provide useful information for understanding the binding sites and for further selective drug design against SARS and other coronavirus.     

反相高效液相色谱法测定肾复康胶囊中的野黄芩苷和芦丁

建立了肾复康胶囊中野黄芩苷和芦丁的反相高效液相色谱测定方法。以甲醇-水为提取溶剂,采用超声提取法对样品进行前处理。以0.02 mol/L磷酸二氢钾缓冲溶液(含1.0％（体积分数）冰醋酸)-甲醇（体积比为63∶37）为流动相,于330 nm波长下检测,肾复康提取液中野黄芩苷和芦丁可达基线分离,分析时间在20 min内。野黄芩苷和芦丁在10 ~300 mg/L内,其峰面积与浓度之间线性关系良好,目标物的加标回收率大于98％。该方法适用于肾复康胶囊及相关药材中野黄芩苷和芦丁黄酮类化合物的测定和质量控制。     

Synthesis and properties of tadpole-shaped gold nanoparticles

In this communication, gold nanoparticles with a tadpole shape were synthesized by a simple aqueous-phase chemical method. The unusual three-dimensional and crystallized structures were demonstrated by TEM, AFM, and HRTEM methods. The SEM and UV-visible absorption measurements and electrophoresis experiments revealed that the tadpoles had novel optical and electrical properties. These attractive structures and properties are expected to find uses in many fields such as electrics, optics, electrochemistry, and biological sensing.     

Synthesis of a novel C2-symmetric thiourea and its application in the Pd-catalyzed cross-coupling reactions with arenediazonium salts under aerobic conditions

[reaction: see text] A novel thiourea-based C2-symmetric ligand was synthesized, and its application in the palladium-catalyzed Heck and Suzuki coupling reactions of arenediazonium salts was evaluated. The reactions, which were performed at room temperature, without added base, and under aerobic conditions, produced product in 4 h with good yield. The corresponding arenediazonium salts were easily generated in one step from anilines.     

新的手性双膦配体的合成及其在苯乙烯不对称氢酯基化中的应用

以甘露醇和山梨醇为原料,合成了2个新的手性膦配体,并用这些新的手性膦配体与钯原位生成的催化剂体系催化苯乙烯的不对称氢酯基化反应,得到R构型的2－苯基丙酸甲酯,其ee值分别为28.5%和13.6%。     

花状Cu_2O/Cu复合材料的光催化性能

不采用任何模板,利用原位逐步水热方法一次性合成了花状Cu2O/Cu复合材料.采用X射线衍射、扫描电镜、高分辨透射电镜和自动吸附仪对样品的相结构、形貌和比表面积进行了表征.以偶氮染料Procion Red MX-5B为探针分子,对复合催化剂进行了可见光催化表征.结果表明该复合催化剂中的Cu和Cu2O之间存在相互作用,其催化活性远高于单相Cu2O和商用P25粉末,有望成为污水治理的新型材料.     

碱性季铵盐“一锅法”催化合成四氢苯并[b]吡喃的水相反应研究

报道了以2-二甲氨乙基苄基二甲基氯化铵为催化剂,在水相介质中"一锅法"催化芳醛、丙二腈和5,5-二甲基-1,3-环己二酮合成2-氨基-3-氰基-4-芳基-7,7-二甲基-5-氧代-4H-5,6,7,8-四氢苯并[b]吡喃的方法.该法具有产率高、反应时间短、操作简便、对环境友好、催化剂可重复使用等优点.     

费托合成钴基催化剂的研究进展

 费托合成油技术是煤炭、天然气等含碳资源清洁优化利用的重要途径, 其关键问题之一是催化剂选择性的调控, 即抑制甲烷生成和提高馏分油含量. 近 10 年来, 中国科学院山西煤炭化学研究所系统地开展了钴基费托合成催化剂及制备放大的工程基础研究, 包括钴分散度、还原度与甲烷生成之间的关系, 载体表面疏水性对催化剂性能的影响, 以及采用孔道限域等手段初步实现了产物的选择性调控. 同时, 初步阐明了甲烷生成的结构基础, 并指明了新型馏分油催化剂研发方向. 在此基础上, 研制了新型钴基催化剂, 其具有低甲烷选择性、高重质烃选择性和良好稳定性的特点. 目前, 对 I 型催化剂完成了实验室稳定性验证并实现了工业示范; 对 II 型催化剂 (甲烷选择性约 2%~3%) 完成了稳定性验证.