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金 属 改 性 的Pd / γ Al2 O3 催 化 剂 在 转 移 加 氢 中 的 应 用  [PDF]
郑纯智,张国华,赵德建,张春勇,文颖频
分子催化 , 2009,
Abstract: 研 究 了 Cu、 La、 Ba、 Ce 和 Co 等 多 种 金 属 氧 化 物 对 Pd / γ Al2 O3 催 化 剂 在 3, 5 二 羟 基 苯 甲 酸 转 移 加 氢 制 备3, 5 二 氧 代 环 己 烷 羧 酸 反 应 中 的 活 性 影 响 , 发 现 镧 的 改 性 效 果 最 明 显 . 得 到 的 Pd LaOx / γ Al2 O3 催 化 剂 在 150 ℃下 还 原 , 催 化 3, 5 二 羟 基 苯 甲 酸 转 移 加 氢 反 应 的 转 化 率 和 选 择 性 分 别 达 到 了 90. 6% 和 98. 2% . 在 150 ℃ 下 PdCl2被 还 原 为 Pd, 而 La 保 持 氧 化 态 . 经 TPR、 SEM、 TEM、 XPS 等 手 段 分 析 后 认 为 , 引 入 的 La 使 Pd 具 有 适 宜 的 粒 度 ,低 温 还 原 时 保 持 氧 化 态 的 La 与 载 体 产 生 相 互 作 用 , 并 对 Pd 的 转 移 加 氢 活 性 的 提 高 有 利 , 而 高 温 下 被 还 原 的 La则 对 提 高 Pd 的 活 性 不 利 .
牡丹春节催花技术  [PDF]
高宏秀,张莹
北方园艺 , 2014,
Abstract: 在筛选了6个适宜春节催花的牡丹品种“洛阳红”、“肉芙蓉”、“乌龙捧盛”、“迎日红”、“赵粉”、“胡红”的基础上,于春节前60~65d将优选的大田催花牡丹苗起苗、上盆至温室中栽培,进行剥芽、涂抹赤霉酸等催花处理,并采取一定的修剪、肥水、病虫害防治等栽培措施,从而获得在春节开花的优质盆栽牡丹。
Characterization and Catalytic Performance of Niobic Acid Dispersed over Titanium Silicalite  [PDF]
Didik Prasetyoko,Zainab Ramli,Salasiah Endud,Hadi Nur
Advances in Materials Science and Engineering , 2008, DOI: 10.1155/2008/345895
Abstract: Niobic acid, Nb2O5?nH2O, has been supported on the titanium silicalite by impregnation method. The obtained materials were characterized by X-ray diffraction, infrared, and ultra-violet—visible diffuse reflectance spectroscopy, temperature programmed reduction, pyridine adsorption, and field emission scanning electron microscopy techniques. It was demonstrated that the tetrahedral titanium species still retained after impregnation of niobic acid. The results revealed that niobium species interacted with hydroxyl groups on the surface of TS-1. The niobium species in the catalysts are predominantly polymerized niobium oxides species or bulk niobium oxide with the octahedral structure. All catalysts showed both Brønsted and Lewis acid sites. The catalysts have been tested for epoxidation of 1-octene with aqueous hydrogen peroxide. It was found that the presence of niobic acid in the catalysts enhanced the rate of the formation of epoxide at the initial reaction time. Diol as a side product was also observed due to the acidic properties of the catalysts.
抗疟药物的研究ⅰ.4-羟基-7-氯喹啉酸制备的改進  [PDF]
王其灼,耿国武,張在鈞,董祖兴,沈仲柟
药学学报 , 1963,
Abstract: 抗疟药氯喹生产的重要中间体——4-羟基-7-氯喹啉酸(ⅴ),原用的甲脒法,缩合收率很低。经改进,加原甲酸乙酯参与反应,并找到硝酸铵为有效催化剂,控制适当的反应条件,从间氯苯胺至ⅴ的四步反应,总收卒为75—80%。即单批的收率较原法提高了5倍以上。经推广到生产上,解决了主要技术关键,与现有各生产路线相较,有其独特的先进性。
四价掺杂铌酸锂晶体  [PDF]
红外与毫米波学报 , 2009,
Abstract: 综述了四价掺杂(包括铪和锆)铌酸锂晶体的研究进展.掺铪铌酸锂晶体具有与掺镁铌酸锂晶体相似的抗光折变性能,而掺锆铌酸锂晶体的抗光折变性能远优于掺镁铌酸锂晶体.铪铁双掺与锆铁双掺铌酸锂晶体兼有高光折变灵敏度和高光折变衍射效率的性质.并且在掺杂量超过阈值时,铪离子和锆离子在铌酸锂晶体中都具有接近于1的有效分凝系数.这些实验结果表明,四价掺杂铌酸锂有望成为出色的非线性光学晶体.
Coating of Mineral Acids with Niobic Solid Acid for Preparing Furfural from Nut Shell of Camellia oleifera Abel  [PDF]
Lisong Hu, Menghao Du, Jingping Zhang
Open Journal of Forestry (OJF) , 2016, DOI: 10.4236/ojf.2016.65037
Abstract: Nut shell of Camellia oleifera Abel which has large scale of plantation in mountainous region of southern China is abundant renewable resource. The nut shell is suitable for preparation of furfural, as the content of which is as much as 16% (based the dried nut shell). In early time, mineral acids were employed as typically catalyst for preparing of furfural from the nut shells. These mineral acids could pollute water and corrode equipment. In this paper we used various mineral acids coating with niobic acid as catalysts to investigate reactions for preparation of furfural. Among these catalysts, the catalyst of sulfuric acid coating with niobic acid was found to be very effective, which had higher hammett acidity and better effect of hydrolysis of the nut shells; The catalysts of sulfuric acid coating with niobic acid was characterized, and the conditions of preparation of the catalyst were investigated. The optimum conditions were: sulfuric acid as coating acid, the concentration of sulfuric 1.1 mol/L, impregnation time 8 h, calcination time 8 h and calcination temperature 450°C. Then hydrolysis of the nut shells was explored, the optimum conditions were as follows: dose of catalyst 20%, ratio of solid to liquid 1:15, reaction temperature 100°C, reaction time 4 h; Under this condition, the yield of furfural was 8.7%.
电催陈酒效果的分析  [PDF]
张惠苓,关紫烽,李翠荣,王宏钧
中南民族大学学报(自然科学版) , 2003,
Abstract: 为检验电催化方法对催陈酒的效果,对新生产的未经催陈处理的酒、自然陈酿的3年的出厂成品酒及经催陈处理后又存放6个月的酒,进行了气相色谱分析,分析结果表明:新酒与自然陈化及催陈处理的酒的组成、含量有明显的不同,经催陈处理的酒的组份、含量比较接近于自然陈酿酒,而与新酒有较大差别,催陈酒中甲酸乙酯及乙酸乙酯的含量明显提高,甲醇及乙醇含量明显降低,而对调味起特别作用的醛类含量明显提高,电催化方法催陈有效可行。
Optical limiting of niobic tellurite glass induced by self-trapped exciton absorption of the AgCl nanocrystal dopant
ZhenYu Zhao,Jian Lin,TianQin Jia,ZhenRong Sun,ZuGeng Wang
Chinese Science Bulletin , 2009, DOI: 10.1007/s11434-009-0143-1
Abstract: Niobic tellurite glass doped by silver chloride nanocrystal was prepared with the melting-quenching and heat treatment method, and the self-trapped exciton absorption band of the silver chloride nanocrystal was observed at 532 nm in the UV-visible absorption spectrum. The glass structure characteristics were investigated by Raman spectroscopy, and the mechanism of self-trapped exciton was analyzed by Jahn-Teller model. Its optical limiting was measured with 532 nm picosecond laser pulses, and the corresponding nonlinear absorption coefficient was measured with open-aperture Z-scan. The experimental results showed that optical limiting at 532 nm was attributed to free carrier absorption between the self-trapped state and the continuum band.
观赏凤梨乙烯催花机理的研究进展  [PDF]
信彩云,李志英
热带农业科学 , 2009,
Abstract: 综述近年来观赏凤梨植物的乙烯催花技术及其机理的研究进展,介绍乙烯应用于催花的发展道路,简述其在凤梨科植物催花中的应用,并对目前研究中存在的问题和今后发展提出建议。
催花保鲜剂对百合(lilium)绿蕾催花保鲜生理的研究  [PDF]
刘雅莉?,王 飞?,丁 勤?
西北农林科技大学学报(自然科学版) , 2000,
Abstract: 探讨了百合切花绿蕾经两种催花保鲜剂处理后的效果,结果表明,催花保鲜剂能促进绿蕾提前开花,同时对开花后的百合切花有延缓衰老的作用,减少了切花在瓶插期间叶绿素与蛋白质含量的降解,提高了切花的品质和商品价值。处理ⅰ增加了开放率和花蕾长度,处理ⅱ增加了花瓣长和花径大小,同时在试验过程中揭示了百合切花经催花剂处理后的水分生理变化规律,筛选出最佳的催花保鲜剂为处理ⅰ。
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