全文获取类型
收费全文 | 34篇 |
免费 | 8篇 |
专业分类
综合类 | 2篇 |
化学工业 | 26篇 |
金属工艺 | 1篇 |
轻工业 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 10篇 |
出版年
2022年 | 1篇 |
2021年 | 1篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 3篇 |
2015年 | 1篇 |
2012年 | 3篇 |
2011年 | 1篇 |
2009年 | 1篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 3篇 |
2002年 | 1篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
排序方式: 共有42条查询结果,搜索用时 15 毫秒
1.
以酸性多孔ZSM-5沸石(HZSM-5-M)和高比表面积的氧化硅(SiO2)为载体,采用等体积浸渍法制备了负载Ni2P催化剂(Ni2P/HZSM-5-M和Ni2P/SiO2),对比研究了它们在苯乙炔选择性加氢反应中的催化性能。采用XRD、N2吸附-脱附、NH3-TPD、H2-TPR、SEM和TEM对载体及其负载的Ni2P催化剂进行了表征。催化剂活性结果为:当反应时间为2 h,苯乙炔在Ni2P/HZSM-5-M催化剂的转化率为98.5%,而在Ni2P/SiO2催化剂上仅为45.6%。说明Ni2P/HZSM-5-M催化剂的加氢活性显著高于Ni2P/SiO2催化剂。这是因为,与Ni2P/SiO2催化剂相比,在Ni2P/HZSM-5-M催化剂上形成了小颗粒的Ni2P活性相。同时,Ni2P/HZSM-5-M催化剂的活性具有良好的重复性。 相似文献
2.
In the copolymerization of phenylacetylene with various acetylenes catalysed by WCl6·Ph4Sn, the relative reactivity of monomer decreased with increasing steric effect of monomer, e.g. HC Cn-Bu, HC Cn-Hex > HC CPh, HC Cs-Bu > HC Ct-Bu, MeCCPh, CICCPh. While 1-chloro-2-phenylacetylene (a disubstituted acetylene) showed high reactivity in the homopolymerization by Mobased catalysts, the reactivity was remarkably depressed in the presence of phenylacetylene as comonomer. Based on these results, the relative reactivity of the acetylenic monomers in copolymerization was explained in terms of competitive coordination of monomers to the propagating end. 相似文献
3.
Enantiomeric Nanostructures: Chiral Nanostructures from Helical Copolymer–Metal Complexes: Tunable Cation–π Interactions and Sergeants and Soldiers Effect (Small 2/2016)
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
4.
Giseop KwakToshio Masuda 《Polymer》2002,43(3):665-669
(+)-p-[{Methyl(1-naphthyl)phenyl}germyl]phenylacetylene, an acetylene with a bulky chiral germyl group, was polymerized with [(nbd)RhCl]2-Et3N to give a high-molecular-weight polymer in good yield. The CD spectrum of the polymer exhibited very large molar ellipticities [θ] in the UV region in non-aromatic solvents (e.g. THF and CHCl3). In contrast, the CD signals of the polymer in aromatic solvents (e.g. toluene, tetralin, and benzene) became appreciably smaller: [θ]max=6.4×104 (330 nm) and −4.7×104° cm2 dmol−1 (370 nm) in CHCl3; [θ]max=1.1×104 (330 nm) and −0.7×104° cm2 dmol−1 (370 nm) in toluene. The [θ]max values of the polymer in aromatic solvents increased when the solutions were heated, which is attributed to decreased π-π interaction between the solvents and side groups. 相似文献
5.
O. Mukbaniani T. Tatrishvili G. Titvinidze N. Mukbaniani L. Lezhava N. Gogesashvili 《应用聚合物科学杂志》2006,100(3):2511-2515
The hydrosilylation reaction of α,ω‐bis(trimethylsiloxy)methylhydridesiloxane to phenylacetylene in the presence of catalyst—platinum hydrochloric acid (0.1M solution in tetrahydrofuran)—at 1 : 35 ratio of initial compounds, at various temperatures (40–60°C) was investigated and methylsiloxane oligomers with phenethenyl substituted groups in the side chain has been obtained. It was shown that complete hydrosilylation of all active (Si? H groups do not take place. The hydrosilylation reaction order, activation energy, and rate constants were found. The synthesized oligomers were characterized by 1H and 13C NMR and IR spectral data. Gel‐permeation chromatographic, differential scanning calorimetric, thermogravimetric, and wide‐angle X‐ray investigations of synthesized oligomers were carried out. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2511–2515, 2006 相似文献
6.
7.
Victor Sans Anna M. Trzeciak Santiago Luis Józef J. Ziółkowski 《Catalysis Letters》2006,109(1-2):37-41
Efficient cross-coupling and carbonylative coupling of terminal alkynes with aryl iodides catalyzed by PdCl2(P(OPh)3)2 in the presence of NEt3 in toluene and in ionic liquids is described. In imidazolium ionic liquids, [bmim]PF6 or [mokt]PF6 (bmim = 1-butyl-3-methyl imidazolium cation, mokt = 1-methyl-3-octyl imidazolium cation) catalyst was recycled and used in
four concecutive catalytic cycles with high activity. In the absence of aryl iodide the same catalytic system catalyzed head-to-tail
dimerization of phenylacetylene to the 1,3-diphenyl enyne, trans-PhC ≡ C–C(Ph)=CH2, with a yield of 85%. 相似文献
8.
9.
Copolymers of p-diethynylbenzene with phenylacetylene in the presence of cobalt-tri-n-butylphosphine in diethylamine at room temperature with high molecular weight were synthesized. The copolymers, having the advantage of being highly soluble in common organic solvents, possess mainly trans π-conjugated polyene main chains and phenyl together with phenyl ethynyl side chains. © 1999 Society of Chemical Industry 相似文献
10.
综述了高性能/高温聚合物中的反应性端基齐聚物与热固性聚酰亚胺及其固化技术,其包括PMR-15、PMR-Ⅱ,端乙炔基聚酰亚胺、苯乙炔封端聚酰亚胺、Thermcon聚酰亚胺、其它热固性聚酰亚胺、苯并环丁烯端基聚酰亚胺,对其化学结构与性能的关系也进行了讨论。 相似文献