Synthesis of Zeolite ZSM-2 Using Zeolite NaX as Seeds

Introduction Oxygen and nitrogen have been produced tradition-ally by cryogenic distillation of air. Methods for the non-cryogenic separation based on selective adsorption have been developed and commercialized since the 1970s and have led to a cost-effective process for this important separation.1 Low-silica zeolites are important materials for producing oxygen by selective adsorption of nitrogen. In 19891990, a new generation of lith-ium-based adsorbents was developed.2,3 Highly lithium exc…     

Au/Ag核一壳结构复合纳米粒子形成机制的研究

在已制备好的Au纳米粒子表面,通过化学还原的方法沉积生长Ag包覆层,通过 控制Au, Ag的比列,制备了粒度均匀且粒径可控的Au/Ag核-壳结构纳米粒子。利用 UV-vis吸收光谱和透射电子显微镜（TEM）对SAu, Ag摩尔比为1：10的复合纳米粒 子的光学性质和形态进行随时监测,直接观察了核-壳结构纳米粒子的生长过程： 一部分Ag+在Au核表面还原生长,溶液中其余Ag+还原形成银的纳米团簇向粒子表面 的继续沉积生长,壳层增厚。     

Properties of the seed gum of stryphnodendron barbatiman (Barbatimäo)

Pretreatment resulting in enzymatic inactivation proved to be essential for the preparation of highly viscous solutions of the galactomannan from seeds ofS. barbatiman ([η]= 1400 mL/g). Short periods of reflux with aqueous methanol or ethanol or treatment with boiling water of the seeds was used. The target for the inactivation step is a β-d-endo-mannanase activity present in the dormant seeds.     

晶种存在形态对所合成的SAPO-34分子筛性质及其甲醇转化催化性能的影响

采用常规水热合成法、添加粉末晶种和添加含有分子筛前驱体的液相晶种等方法制备了低硅铝比的SAPO-34分子筛。采用XRD、SEM、FT-IR及TPD等表征手段研究了合成方法对晶体结构、形貌、晶粒粒径及酸性的影响。并在固定床上对比了其甲醇转化制烯烃的催化性能差异。结果表明,晶种存在形态对分子筛的结晶度影响不大,但影响了硅在骨架中的分布、晶粒粒径和酸性等。与添加粉末晶种相比,采用含有分子筛前驱体的液相晶种法更有利于减小分子筛晶粒粒径,降低分子筛酸性,提高低碳烯烃选择性。     

Production of glycerides from glycerol and fatty acids by native lipase ofNigella sativa seed

The possible application of native lipase ofNigella sativa seed in the esterification of fatty acids to glycerol was investigated, and the effect of process parameters and the enzyme selectivity on the reaction were determined. For this aim, the esterification of oleic acid, sunflower oil fatty acids, and coco oil fatty acids with glycerol were studied.     

Methyl ester from safflower seed oil of Turkish origin as a biofuel for diesel engines

The primary problems associated with the use of pure vegetable oils as fuels in compression ignition (Diesel) engines are caused by high fuel viscosity. Transesterification of the oil with short-chain alcohols (such as methanol or ethanol) to corresponding fatty esters is the most promising solution to the high-viscosity problem. In this work, the transesterification method was applied to crude safflower seed oil of Turkish origin using methanol. The variables affecting the monoester yield, such as:

Purification,Characterization and Physico‐Chemical Properties of Three Galactose‐Specific Lectins from Pumpkin (Cucurbita Maxima) Seed Kernels

Three galactose‐specific lectins have been isolated and purified from the extract of pumpkin seed kernels by gel filtration on Sephadex G‐75 with 100% ammonium sulfate saturated crude extract, followed by ion exchange chromatography on DEAE‐cellulose and affinity chromatography on Sepharose 4B. All three lectins were found to be homogeneous as judged by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS‐PAGE). The molecular weights of lectins, PSL‐1, PSL‐2 and PSL‐3, as estimated by gel filtration on Sephadex G‐75 were 40,000, 42,000 and 46,000, and by SDS‐PAGE about 39,500, 41,000 and 45,000, respectively. The lectins, PSL‐1, PSL‐2 & PSL‐3 were dimer in nature and the molecular weights of their subunits were about 25,500 and 14,000; 26,000 and 15,000; and 30,500 and 15,000, respectively. The lectins are glycoproteins with a neutral sugar content of 3‐5%. The lectins agglutinated rat red blood cells and the hemagglutination was inhibited specifically by galactose and galactose‐containing saccharides. The lectins exhibited a strong cytotoxic effect in a brine shrimp lethality bioassay.     

载铁环烷酸-异辛醇-煤油体系异相水热反萃

水热反萃技术是指在较高的温度条件下,负载金属有机相与水反应,金属氧化物或氢氧化物直接沉淀结晶出来的过程[1,2]。与制备金属氧化物或氢氧化物的其它方法[3,4]相比,水热反萃克服了直接水解法难以控制氧化物粒度的弊病;减少了化工产品的消耗,避免了人为地引入杂质和大量废液的产生[5-8]等。但目前关于水热反萃的动力学数据非常贫乏。本文考察了在外加晶种(Fe2O3)情况下,对载铁环烷酸有机相异相水热反萃速率的影响,导出了速率方程和反萃百分数与时间的关系式。总反应式表示为:[2,3,9]Fe2(OH)2R4(org)+H2OFe2O3(s)+2H2R2(org)(1)1　…     

薏苡仁挥发性成份的分析

本文应用同时蒸馏－萃取装置提取了薏苡仁的挥发物质，用ＧＣ／ＭＳ方法分离鉴定了５５种成份，其中主要成份为醇类（１４．１％）、醛类（９．８５％）、酮类（３．０７％）、酸类（５．９６％）、酯类（２．７４％）、烃与萜类（５０．４３％）、杂环类（１２．４５％），占总挥发物质的９８．６％。     

Polystyrene(1)/poly(butyl acrylate-methacrylic acid)(2) core-shell emulsion polymers. Part I. Synthesis and colloidal characterization

Polystyrene (PS) (1)/Poly(n-butyl acrylate (BA)-methacrylic acid (MAA)) (2) structured particle latexes were prepared by emulsion polymerization using monodisperse polystyrene latex seed (118 nm) and different BA/MAA ratios. Three main aspects have been investigated: i) the polymerization kinetics; ii) the particle morphology as a function of reaction time; iii) the distribution of MAA units between the water phase and the polymer particles.The amount of MAA in the shell copolymer was found to be the main factor controlling the particle shape and morphology. The shape of the structured particles was, generally, non-spherical, and the shape irregularities increased as a particles was, generally, non-spherical, and the shape irregularities increased as a function of reaction time. At the beginning of the second stage reaction, new small particles were observed, which coalesced onto the PS seed as the polymerization proceeded. The distribution of the MAA groups in the latex particles and the serum was analyzed by alkali/back-acid titration, using ionic exchanged latexes. No MAA groups were detected in the latex serum. Due to the lowTg of the BA-MAA copolymers, alkali conductimetric titrations accounted for all the MAA groups on and within the polymer particles. Therefore, for these systems, this method is not only limited to a thin surface layer, as it is often assumed.