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141.
LIU Xing-Quan WU Yu-Tang JIA Zhao-XiaChengdu Institute uf Organic ChemistryAcademia SinicaChengdu Sichuan To whom correspondence should be addressed. 《天然气化学杂志》1995,(1)
1 , 5-diazabicyclo['1, 3, 0]non-5-ene(DBN) has been synthesized in our laboratory, and its catalytic activity and selectivity for methanol carbonylation to methyl formate (MF) have been studied. The experimental results have demonstrated that the synthetic processes of DBN used for the present work are reasonable and feasible. The total yield of three steps of DBN synthsis is approximate to 80%. The activity evaluation has shown that DBN can effectively catalyze the carbonylation reaction of methanol in the presence of propylene oxide (PO) promoter. PO-promoted DBN is a novel catalytic system superior to sodium methoxide. 相似文献
142.
在抽空密封石英管内放置元素锌和磷合成ZnP_2过程中, 仔细考察了不同升温程序的实验结果, 发现磷蒸汽压条件对于形成磷化物的性质相当重要, 在大于4大气压时会生成近100%黑色ZnP_2。用缩短合成时间,考察合成过程的中间产物, 以及用称量法、化学分析法和扫描电镜法对中间产物的分析, 提出了ZnP_2合成过程的主要机理。 相似文献
143.
144.
SUN Weimin LUO Juntao HUANG Wenqiang State Key Laboratory of Functional Polymer Material for Adsorption Separation Institute of Polymer Chemistry Nankai University Tianjin China 《Chinese Journal of Reactive Polymers》2002,(1)
1. INTRODUCTION A solid phase organic synthesis (SPOS) has increasingly attracted chemist抯 attention over the past decades [1~3]. It was found that the compounds with biological activity are mostly derived from heterocycle structures. It is therefore no… 相似文献
145.
对烘烤前后南瓜籽中的化学成分进行分析并对比。采用同时蒸馏萃取装置萃取南瓜籽中的挥发性成分,采取超临界CO2萃取技术萃取南瓜籽油脂,并将其分为酸、碱、中性三个部分,用气相色谱-质谱联用方法分析其中化学成分并进行对比。结果表明,南瓜籽挥发性成分中含有多种醛类和酯类化合物,烘烤后产生了大量的烷基吡嗪,其在碱性部分中的相对含量比烘烤前提高14倍多,不饱和醛类化合物含量也有明显提高。南瓜籽油脂中的主要化学成分是油酸、亚油酸及其酯类。还含有生物活性功能成分如植物甾醇、角鲨烯和维生素E等。烘烤后除角鲨烯含量有所降低,维生素E、植物甾醇、亚麻酸等均有提高。 相似文献
146.
The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin isreported. 2-Polystyrylsuifonamidoethanol resin 1 was reacted with acryloyl chloride to afford2-polystyrylsulfonylamidoethyl acrylate resin 2, which was further reacted with brominatedaldoximes by [3+2] cycioaddition to give isoxazoline resin 4. Resin 4 was treated with aqueous 6mol/L HCI solution to obtain isoxazolines in good yield and purity. 相似文献
147.
A new fertilizer of cocrystal type,known as durably efficacious ammonium bicarbonate (DEAB),has been developed by adding a certain amount of dicyandiamide (DCD) as an ammonia-stabilizing agent to ammonium bearbenate(AB)during the process of its production.As compared with AB,DEAB was found to have a reduction of direct volatilization loss by 53%,a fertilizer availability period prolonged from 35-45 to 90-110 d,and an increase in the rate of nitrogen in fertilizer being utilized by 5.9%-10.2%,and a saving of the amount of fertilizer to be ap-phed by 20%-30% for the same level of yield,or an increase of the crop yield by over 10% for the same level of ni-tregen fertilization;in addition,it was found to show usually a function of promoting the crop to early mature.It can be apptied as basal dressing all in one time to soil and thus also used as a labour-saving and crop yield-increasing fertil-izer for is non-mtertillage,plastics film covering and water-saving agriculture 相似文献
148.
凝胶-燃烧法合成YAG∶Eu3+纳米荧光材料的结构和发光性能 总被引:6,自引:0,他引:6
Y3Al5O12∶Eu nanophosphors were synthesized by a gel combustion method. The structure of phosphors was characterized by XRD and FTIR. YAG phase came to occur when YAG∶Eu precursors were sintered at 800 ℃, although the phase was mainly amorphous. The organic groups pyrolyzed completely and pure YAG phase was obtained in the samples sintered at 900 ℃. In the formation of YAG phase, no intermediate phases such as YAP and YAM were detected. Both 5D0 → 7F1 orange and 5D0 → 7F2 red emission could be observed for all the sintered samples. However, the emission of amorphous samples was greatly different from that of crystalline ones. The former was mainly 5D0→ 7F2 red emission, but the latter was 5D0 → 7F1 orange emission. As sintering temperature rises, the ratio of orange to red for phosphors increases. Eu could be doped up to 8% in YAG host lattice, and fluorescence quenching was absent. It indicated that the gel combustion synthesis method can increase emission intensity and quenching concentration due to a good distribution of Eu3+ activators in Y3Al5O12 matrix. 相似文献
149.
Oxygen Atom Adsorption and Diffusion on Pd Low-index Surfaces and (311) Stepped Surface 总被引:2,自引:0,他引:2
Introduction Atom adsorption on transition metal surfaces has attracted special attention as a base for understanding the fundamental processes of oxidative catalysis. Particularly interesting is the adsorption and diffusion of oxygen on well-defined metal surfaces. An oxygen covered palladium surface, for example, plays a central role in several important reactions such as oxidation of carbon monoxide and ammonia. In particular, the (100), (111), (110) surfaces and the interactions with oxyge… 相似文献
150.
采用水热法合成了MoVTeNbOx多组分氧化物催化剂, 并用XRD, ICP, BET和SEM等方法对催化剂进行了表征, 考察了MoVTeNbOx多组分氧化物催化剂的组成、反应温度和空速对异丁烷选择氧化反应性能的影响. 其中组成为MoV0.3Te0.17Nb0.12Ox的催化剂显示出最好的催化活性和选择性, 在673 K下, 异丁烷的转化率为10.8%, 甲基丙烯醛(MAL)和甲基丙烯酸(MAA)的收率累积达到6.5%. 相似文献