Solid-state nanopores for ion and small molecule analysis

Solid-state nanopore in analytical chemistry has developed rapidly in the 1990s and it is proved to be a versatile new tool for bioanalytical chemistry. This review focuses on the analysis of ions and small molecules with nanopores including nanopipettes, polymer film nanopores, Si₃N₄ nanopores, graphene nanopores, MoS₂ nanopores and MOFs.     

离子液体萃取阿魏酸和咖啡酸的性能研究

以1-甲基-3-丁基咪唑六氟磷酸盐([C4mim][PF6])和1-甲基-3-己基咪唑六氟磷酸盐([C6mim][PF6])离子液体为萃取剂,采用紫外分光光度法研究了溶液pH值、温度、相比率及盐的种类和浓度对其萃取阿魏酸和咖啡酸效率的影响,考察了被萃取物的回收及离子液体的循环使用,探讨了两种离子液体替代传统有机溶剂阿魏酸和咖啡酸的可能性。实验结果表明:萃取温度和无机盐的种类及浓度对FA和CA萃取效率的影响较小;水相pH值对萃取效率有较大的影响,萃取FA适宜pH应小于3.67,萃取CA适宜pH应小于3.71;被萃取物浓度增大,萃取效率降低,而相体积比增大其萃取效率升高;两种离子液体对FA和CA的萃取效率[C4mim][PF6]大于[C6mim][PF6],同种离子液体对FA的萃取效率大于CA;在萃取相中的FA和CA可定量回收,且被萃取物中离子液体的残留[C6mim][PF6]小于[C4mim][PF6],离子液体可循环使用。     

锌,锰对K—Fe／ZSM—48CO加氢催化反应性能的影响

锌、锰对ＫＦｅ／ＺＳＭ４８ＣＯ加氢催化反应性能的影响范彬彬马静红樊卫斌李瑞丰曹景慧（太原工业大学精细化工研究所，太原０３００２４）关键词ＣＯ加氢，ＺＳＭ４８，助剂效应ＫＦｅ／ＺＳＭ４８在一氧化碳加氢合成低碳烯烃的反应中表现出良好的性能。沸石载体不仅...     

Analysis of flavonoids in <Emphasis Type="Italic">Ginkgo biloba</Emphasis> L. and its phytopharmaceuticals by capillary electrophoresis with electrochemical detection

A high-performance capillary electrophoretic (CE) method with electrochemical detection (ED) has been developed for determination of the pharmacologically active flavonoids in Ginkgo biloba L. and phytopharmaceuticals containing its extract. Epicatechin, catechin, rutin, apigenin, luteolin, and quercetin are important flavonoids in this plant. Operated in a wall-jet configuration, a 300 micro m diameter carbon-disk electrode was used as working electrode with good response to the six analytes at +1000 mV (relative to the SCE). Under the optimum conditions, the analytes were separated within 22 min in a borax buffer (pH 9.0). Excellent linearity was obtained over two orders of magnitude and detection limits (S/N=3) ranged from 1.4 x 10(-7) to 5.0 x 10(-7) g mL(-1) for all six analytes. The method was successfully used for assay of Ginkgo biloba L. and its phytopharmaceuticals after a relatively simple extraction procedure; the results obtained were satisfactory.     

Potentiometric immunosensor based on antiserum of Japanese B encephalitis immobilized in nano-Au/polymerized o-phenylenediamine film

A novel potentiometric immunosensor for detection of Japanese B encephalitis vaccine was developed by immobilizing antiserum of Japanese B encephalitis on nano-Au/polymerized o-phenylenediamine (o-PDA) film on the platinum (Pt) electrode. The performance and factors influencing the performance of the resulting immunosensor were studied. The immunosensor showed a specific response to Japanese B encephalitis vaccine in the range 1.1 × 10⁻⁸ to 2.0 × 10⁻⁶ lgpfu/ml (plaque forming unit) with a detection limit of 6 × 10⁻⁹ lgpfu/ml. The correlation coefficient is 0.9986. The incubation time, incubation temperature, pH, reproducibility and stability of the immunosensor were also studied. The present work supplied a promising test method for biological products.     

新颍Mo-Cu-Se簇合物{MoCu3Se3I}(PPh3)3O·0.5CH2Cl2的合成及晶体结构

新颍Mo-Cu-Se簇合物{MoCu₃Se₃I}(PPh₃)₃O·0.5CH₂Cl₂是由［Et₄N］₂MoSe₄、Cu(PPh₃)₂NO₃和KI在乙腈和二氯甲烷1∶1的混合溶剂中反应所得。晶体属单斜晶系，空间群P2_{1相似文献}   

铁电极上硫脲及衍生物的缓蚀作用研究

用极化曲线方法测定了硫酸溶液中硫脲及其衍生物的浓度变化对铁腐蚀电化学行为的影响，获得了腐蚀电位下缓蚀剂对阴极和阳极过程的作用系数，用ＥＨＭＯ方法对硫脲及其衍生物的结构参数进行了量化计算，分析表明，缓蚀剂对阴极和阳极过程作用系数的大小与这些参量有密切关系。     

Chemical constituents from the roots of <Emphasis Type="Italic">Polygonum bistorta</Emphasis>

Investigation of the roots of Polygonum bistorta L. afforded seven compounds including five triterpenoids, a coumarin, and a steroid, the structures of which were identified by EIMS, ¹H NMR, ¹³C NMR, DEPT, and HMBC experiments. All the compounds have been isolated from Polygonum genus for the first time. Published in Khimiya Prirodnykh Soedinenii, No. 5, pp. 463–465, September–October, 2007.     

PREPARATION AND CHARACTERIZATION OF SHISH-KEBAB TYPE LIQUID CRYSTALLINE POLY（p-PHENYLENEVINYLENE）

Novel shish-kebab type liquid crystalline poly（p-phenylenevinylene） derivatives were synthesized by Stille coupling reaction from 2,5-bis[（4-n-alkoxyl）benzoyloxy]1,4-dibromobenzene （monomer l） and 1,2-bis（tributylstannyl） ethylene （monomer 2）. The polymers with alkoxy groups are soluble in common organic solvents and exhibit blue fluorescence. Both the cast film and the annealed film have large red-shifts in fluorescence spectra and show yellow fluorescence. The polymers with CN and NO2 groups show poor solubility and green fluorescence. All the polymers possess liquid crystalline smectic phases. The melting point （Tm） of the polymers decreases when the length of the alkoxy tails of the mesogenic units increases. The polymers are easily aligned under a magnetic field of 10 Tesla. It is found that the conjugated backbone and LC side chain are aligned perpendicular and parallel to the magnetic field, respectively. The polymers show optical dichroism in fluorescence spectra, suggesting that they are available for advance materials with linear optical polarization.     

Exciton interactions in CdS nanocrystal aggregates in reverse micelle

Here we report the formation and spectroscopic properties of cadmium sulfide (CdS) nanocrystal systems: individual nanocrystal and CdS aggregates. The optical absorption and luminescence spectra of the aggregated CdS nanocrystals and individual nanocrystal show exciton aggregate and individual exciton characteristics. Although it is not Bose-Einstein condensation, such aggregated quantum dots (QDs) seem to supply us opportunity to study the interactions and condensation of excitons in multi-QDs system, not in the separated QDs system.