聚苯胺对2,5-二巯基-1,3,4-噻二唑氧化还原反应的电化学催化作用的循环伏安研究

研究了聚苯胺(PAn)膜电极在2,5-二巯基-1,3,4-噻二唑(DMcT)溶液中电化学处理或浸泡后的循环伏安(CV)曲线的变化规律.实验结果表明,PAn膜电极在DMcT溶液中进行电化学处理或浸泡过程可使DMcT进入PAn膜内部与PAn形成复合物.PAn对DMcT的电化学催化作用可能和二者之间形成的电子给体-受体复合物有关.该复合物的电化学氧化还原特性不同于PAn和DMcT,其氧化还原反应速率和可逆性均优于DMcT.     

高浓度杂多酸溶液催化性能的研究1: 一种新型异丁烷/丁烯烷 基化催化剂

在异丁烷、丁烯烷基化反应中研究了一种由杂多酸和醋酸组成的新型液体催化剂的催化性能,醋酸作为溶剂对杂多酸具有共协效应,系统研究了形成活性相的条件,杂多酸结晶水含量对活性相的形成和催化活性均有显著影响,这一催化体系具有与硫酸可比的催化活性。     

可湿气固化的硅烷化聚醚的研究

以聚醚多元醇为原料 ,通过聚氨酯预聚体的方法制得了可湿气固化的硅烷化聚醚 ,研究了温度和时间对反应的影响 ,以及不同NCO/OH比值对固化物力学性能的影响。结果表明 ,固化后形成的弹性体的不同力学性能可通过调节不同NCO/OH的比值而获得     

硒化合物的形态分析进展

硒的毒性和营养功能不仅与其总量有关,而且与其存在的化学形态有关,因此,硒的形态分析对于了解不同形态的硒化物在生物体和环境中的迁移转化规律具有重要意义。综述了硒化合物的不同形态和分析方法和技术。     

3-D mesoporous nano/micro-structured Fe3O4/C as a superior anode material for lithium-ion batteries

Urchin-like nano/micro-structured Fe₃O₄/C composite has been successfully synthesized using inexpensive starting materials. The urchin-shaped nano/micro-structure consisted of several oriented nanorods. TEM analysis revealed that there is a large number of pores and uniform amorphous carbon distribution at a nanoscale in the nanorods walls. As used in lithium-ion batteries, the mesoporous Fe₃O₄/C anode delivered a higher reversible capacity of about 830?mAh?g^?1 at 0.1?C up to 50 cycles, as well as enhanced high-rate capability compared with urchin-like Fe₂O₃ and commercial Fe₃O₄. The improvements can be attributed to the combined effects of the nano/micro-architecture, the porosity, and the ultra-fine carbon matrix, where the three factors would contribute to possess both the merits of nanometer-sized building blocks and micro-sized assemblies and provide high electronic conductivity. It is believed that the results of this study offer new prospects for improving the lithium storage capacity of metal oxides by controlling both architecture and composition.     

电感耦合等离子体原子发射光谱法(ICP-AES)测定金鸡胶囊中的7种无机元素

建立了测定金鸡胶囊中Ca、Mg、Mn、Fe、Cu、Zn和Sr 7种无机元素含量的分析方法.采用浓硝酸和高氯酸(8+2)的混合酸溶解样品,利用电感耦合等离子体原子发射光谱法(ICP-AES)对各种元素进行测定.金鸡胶囊含有丰富的对人体有益的无机元素,对待测样品的测定结果表明,Ca、Mg、Fe、Mn、Zn、Sr和Cu的含量...     

Enhanced Electrocatalytic Performance of Anthraquinonemonosulfonate‐Doped Polypyrrole Composite: Electroanalysis for the Specific Roles of Anthraquinone Derivative and Polypyrrole Layer on Oxygen Reduction Reaction

To analyze the specific roles of anthraquinone‐2‐sulfonate (AQS) and polypyrrole (PPy) layer on oxygen reduction reaction (ORR), the electrocatalytic reduction of oxygen was investigated on the AQS/PPy composite modified graphite electrode. Results show that the enhanced electrocatalytic performance is attributed to the excellent electrocatalytic activity of the immobilized AQS functional groups to mediate two‐electron reduction of O₂ to H₂O₂. The PPy layer may not participate in ORR, but it can further catalyze the two‐electron reduction of H₂O₂ to produce H₂O in the potential range more negative than that the two‐electron reduction of oxygen proceeds efficiently on the AQS sites.     

Sesquiterpenoids from the Aerial Parts of Inula japonica

Fourteen sesquiterpenoids with an eudesmane C‐atom skeleton, including four new ones, (1β,5α,7β,8β,11β)‐5‐hydroperoxy‐1‐hydroxyeudesm‐4(15)‐eno‐12,8‐lactone ( 1 ), (1β,5α,7β,8β)‐8‐(acetyloxy)‐5‐hydroperoxy‐1‐hydroxycostic acid methyl ester ( 12 ), and a mixture of (1β,3β,4β,7β,8β)‐1,3‐dihydroxyeudesma‐5,11(13)‐dieno‐12,8‐lactone ( 7 ) and (1β,3β,4β,7β,8β,11β)‐1,3‐dihydroxyeudesm‐5‐eno‐12,8‐lactone ( 8 ), were isolated from the aerial parts of Inula japonica (Asteraceae). Their structures were determined by extensive spectroscopic methods, and those of 7 and 12 confirmed by means of single‐crystal X‐ray diffraction analysis.     

Bruceines K and L from the Ripe Fruits of Brucea javanica

Bruceine K ( 1 ), a pentacyclic C₂₀‐quassinoid bearing a unique 12,20‐epoxy moiety, and bruceine L ( 2 ), along with the ten known compounds (6S,7E)‐6,9,10‐trihydroxy‐ and (6S,7E)‐6,9‐dihydroxymegastigma‐4,7‐dien‐3‐one ( 3 and 4 , resp.), cleomiscosins A–C, luteoline, quercetine, bruceantinol, pinoresinol, and thevetiaflavone, were isolated from the ripe fruits of Brucea javanica. Bruceines K ( 1 ) and L ( 2 ) were determined to be (1β,2α,11β,12β,14ξ,15β)‐12,20‐epoxy‐1,2,11,13,14,15‐hexahydroxypicras‐3‐en‐16‐one and (1β,2α,11β,12β,15β)‐13,20‐epoxy‐1,2,11,12‐tetrahydroxy‐16‐oxo‐15‐(senecioyloxy)picras‐3‐en‐21‐oic acid methyl ester (senecioic acid=3‐methylbut‐2‐enoic acid), respectively, on the basis of NMR (¹H‐ and ¹³C‐NMR, DEPT, ¹H,¹H‐COSY, NOESY, HMQC, and HMBC) and ESI‐MS data. Among the known compounds, (6S,7E)‐6,9,10‐trihydroxy‐ and (6S,7E)‐6,9‐dihydroxymegastigma‐4,7‐dien‐3‐one ( 3 and 4 , resp.), cleomiscosin C, luteoline, quercetine, and thevetiaflavone were isolated for the first time from the Brucea plants.