A New Sesquiterpene Lactone from Ainsliaea bonatii

A new sesquiterpene lactone, Ainsliaolide A, was isolated from Ainsliaea bonatii. The structure was determined on the basis of spectral data.     

多组分单体接枝聚丙烯/尼龙6反应共混物结晶行为研究

用多组分熔融接枝的方法将甲基丙烯酸缩水甘油酯 (GMA)和苯乙烯 (St)共同接枝到聚丙烯 (PP)上 ,制得具有较高GMA接枝率的多单体接枝聚丙烯 ,PP g (GMA co St) .将PP g (GMA co St)与尼龙 6 (PA6 )进行共混 ,利用扫描电镜 (SEM) ,差示扫描量热计 (DSC)和广角X射线衍射 (WAXD)对共混物的形态和结晶进行了研究 .在共混过程中 ,PP g (GMA co St)与PA6反应原位生成了PP g PA6 ,有效改善了共混物的相容性 ,分散相尺寸明显减小 .在PP g (GMA co St) PA6为 3 7的体系中 ,PP g (GMA co St)出现分级结晶现象 ,其在较低温度下的结晶属于均相成核结晶 .在PP g (GMA co St) PA6为 7 3的体系中 ,由于PA6相分散细微 ,在通常结晶温度下不结晶 ,而是在低温下均相成核与PP g (GMA co St)同时结晶 .WAXD证实体系中接枝PP ,PA6为分别结晶 ,无共晶或新的晶型产生     

Preparation of Nanoelectrode Ensembles by Assembly of Nano—Silver Colloid on Gold Surface

A novel method for preparing silver nanoelectrode ensembles(SNEEs) and gold nanoelectrode ensembles (GNEEs) has been developed. Silver colloid particles were first absorbed to the gold electrode surface to form a monolayer silver colloid. N-hexadecyl nercaptan was then assembled on the electrode to form a thoil monolayer on which hydrophilic ions cannot be transfered. The SNEEs was prepared by removing thiol from silver colloid surface through applying and AC voltage with increasing frequency at 0.20V(vs.SCE). Finally,GNEEs was obtained by immersing a SNEEs into 6 mol/L HNO3 to remove the silver colloid particles. By comparison with other methods such as template method ect., this method enjoys some advantages of lower resistance, same diameter,easy preparation,controllable size and density.     

氢氧化铝镁正电溶胶制备及性能研究

氢氧化铝镁正电溶胶制备及性能研究侯万国，张春光，孙德军，梁晓丽，王果庭（山东大学胶体与界面化学研究所，济南，２５０１００）关键词混合金属氢氧化物，溶胶，超细颗粒混合金属氢氧化物的合成、组成及结构等已得到广泛研究［１，２］．我们也曾用插入法合成了混合金...     

荧光猝灭法测定人发中微量锰

异丙肾上腺素在pH9.91的伯瑞坦 罗比森缓冲溶液中被MnO-4氧化,导致其荧光强度显著减弱。最大激发及发射波长为278nm和616nm,MnO-4浓度在0.01～0.64mg·L-1范围内,荧光强度与浓度呈良好线性关系。将其用于人发中微量锰的测定,得到满意的结果。     

LIQUID CHLOROPRENE-HYDROXYETHYL METHACRYLATE COPOLYMER MODIFIED EPOXY RESIN Ⅱ. N, N-DIMETHYL BENZYL AMINE CURING SYSTEM

A series of liquid chloroprene-hydroxyethyl methacrylate copolymer (CP-HEMA) modifiedepoxy resin were prepared. The effects of CP-HEMA content, curing conditions on physical pro-perties of the modified system were examined. With IR and Viscoelastocuremeter, the curing reactionrate was determined and the mechanism of the curing reaction was discussed. The effects of CP-HEMA content and curing conditions on morphology were mainly observed by scanning electronmicroscopy.     

棒状钡铁氧体的反相微乳法制备

A rodlike barium ferrite precursor with an average size of 0.72～19.6 μm and aspect ratio of 2.6～8.3 has been successfully prepared in an inverse microemulsion consisting of isooctane, cetanyl trimethyl ammonium bromide (CTAB), n-C₄H₉OH and water with ammonia and ammonium oxalate as precipitants. On sintering at 780(C, the rodlike precursor particles could be transformed into rodlike particles of barium ferrite(BaFe₁₂O₁₉) with the average size and aspect ratio of 0.69～18.2 μm and 2.3～5.8, respectively. The effect of volume ratio of aqueous phase to oleic phase, the starting concentrations of metal ions and the starting concentration ratios of metal ions to precipitants were investigated.     

N-烷基化手性氨基醇配体的合成

本实验制备了不同构型的两种N-单烷基和N-双烷基的新的手性氨醇配体。     

The Purification and Rapid Identification of Heavy Metal-binding Peptides of Water Hyacinth

This paper studies the rapid identification of heavy metal-binding peptides (phytochelatin) by taking Water Hyacinth as a model plant. Plants were cultured in water containing 2 μg/ml Cd2+ for 13 days. The Sephadex G-50 chromatography of root extract under low salt concentration (0. 01 mol/L PBS) gave a Cd-binding peak with MW of 10 ,000 determined by SEC HPLC. After oxidation with performic acid, its SEC HPLC molecular weight decreased to below 1300 and the reverse phase HPLC showed one peptide peak, whose amino acid composition is the same as that of the sample never undertaking oxidation, and (Glu/Gln):Cys:Gly=2:2:1. According to the general structure of phytochelatin (γ-Glu-Cys)n-Gly, n is 2 in this case. The protocol including the sequential steps of Sephadex G-50 chromatography→performic acid oxidation→reverse phase HPLC→amino acid analysis is a rapid and effective method to identify the existence of phytochelatin and determine its values of n.