Two New Pyrrolizidines from Ligularia lankongensis

Two new pyrrolizidines named lankongensisine A (1), B (2) were isolated from the roots of Ligularia lankongensis collected in Lijiang, Yunnan, and their structures were established by spectroscopic analysis.     

液相色谱-串联质谱法同时检测饲料中多种抗氧化剂

饲料中添加抗氧化剂能够阻止或延缓饲料中某些营养物质氧化,延长饲料贮存期,从而提高饲料利用率.     

丁二烯－甲基丙烯酸甲酯嵌段共聚物的阴离子聚合及表征

讨论了用阴离子方法进行了二烯与甲基丙烯酸甲酯共聚合的过程，并用ＧＰＣ、ＦＴＩＲ、ＮＭＲ和动态粘弹谱对共聚物进行了表征．证明所得聚合物为具有较高分子量、窄分布的二嵌段共聚物．     

SYNTHESIS OF THE POLYSTYRENE-TYPE ADSORBENTS CONTAINING POLAR GROUPS AND THEIR CAPACITIES IN THE ADSORPTION OF STEVIOSIDE AND GYPENOSIDES

Seven polystyrene-type adsorbents (Ⅰ—Ⅶ) were synthesized by the modification of styrene-divinylbenzene copolymer respectively with hydroxymethyl, aminomethyl, methoxymethyl, phenoxymethyl, (4-hydroxy phenoxy)methyl, (4-acetylphenoxy)methyl, and acetyl groups. Their structures were characterized with chemical methods and physical techniques. The adsorption capacities of the adsorbents to stevioside and gypenosides were determined via batch test in which the HPLC method was used for the analysis of Saponin concentration of solution. The results showed that all the adsorbents could adsorb these saponins to a certain extent, but Ⅵ and Ⅶ had large capacities owing to their moderate polarities.     

κ-卡拉胶热可逆凝胶化行为研究

用固体小角激光散射方法研究κ 卡拉胶 (KC)的热可逆凝胶化行为 .以散色斑点的突停点温度为体系的凝胶化点Tgel,考察了溶液中加入Na+ ,K+ ,NH+4,Ca2 + ,Cu2 + ,Zn2 + 等抗衡离子对Tgel的影响 .结果是随抗衡离子浓度增大Tgel上升 ;Tgel与Na+ 的浓度呈线性关系 ,与K+ ,NH+4,Ca2 + ,Cu2 + ,Zn2 + 等离子浓度的平方根成线性关系 ;另外 ,还得到 30℃时KC在KCl盐溶液中的溶胶 凝胶相图 ,并对比了KC在NaCl溶液中透析前后Tgel的变化 .     

碳化树脂全孔结构分析

本文阐述了改良的MP法,对含中孔和微孔的碳化树脂,用改良的MP法计算其微孔分布;用模型法计算其中孔分布,两种方法分析的和表示其全部孔结构分析。     

钕的氢氧化物和氧化物纳米线的制备及表征

以金属钕为起始原料，采用简单的碱性溶液下水热法制备出氢氧化钕纳米线。所得到的水热产物采用X-射线衍射、扫描电镜和透射电镜等进行了结构与形态表征。研究发现，水热处理的温度、碱液浓度和碱的种类等对水热产物的形貌、长径比和结晶状态有较大影响，提高水热温度和增加碱液浓度有利于氢氧化钕纳米线的生长。在相同水热反应温度(180 ℃)、水热时间(45 h)和碱浓度下，5 mol·L^-1 NaOH溶液体系制备的氢氧化钕纳米线具有较高纯度和较长的长径比，其直径为20～40 nm，长度为2～10 μm。该氢氧化钕纳米线在空气气氛下500 ℃烧结后形成具有体心立方结构的C型Nd₂O₃，该Nd₂O₃仍具有一维纳米线形貌。升高焙烧温度时产物的形貌和相结构都发生了明显变化。     

The Photopolymerization Kinetics of Acryl amide Sensitized with Toluidine Blue-Alcoholamine Induced by He-Ne Laser

Toluidine blue(TB) is a good sensitizer for the polymerization of acrylnmide(AM) induced by He-Ne laser. With TB as a sensitizer and various alcoholamine as donors, the photoredox of TB and the polymerization kinetics of AM induced by He-Ne laser were investigated. It was found that either for the photoredox of TB or for the polymerization of AM, the activity of alcoholamine increases in the order of EOA相似文献   

聚氨酯分子印章的制备和表征

“软平板印刷”微结构制备技术为微米和亚微米器件的制备提供了一条新的途径 [1] ,已被电子学家和材料学家所应用 ,近年来进入了生物学领域[2 ] .本实验室将这一方法与生物分子电子学相结合 ,提出了用于 DNA芯片在片合成的分子印章法 [3,4 ] .分子印章法的实质是接触压印与组合化学相结合的固相界面反应 .聚二甲氧基硅氧烷 ( PDMS)是一种软印刷的优良材料 [5] ,但是由于其疏水性和较差的机械性能 ,必须对其进行改性才能用来制备 DNA分子印章 [6 ] .　　聚氨酯作为一种功能材料 ,由于分子中交替的软、硬链段及其不同的热动力学性能而形成…