全文获取类型
收费全文 | 284篇 |
免费 | 18篇 |
国内免费 | 58篇 |
专业分类
化学 | 334篇 |
晶体学 | 7篇 |
物理学 | 19篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 12篇 |
2020年 | 18篇 |
2019年 | 4篇 |
2018年 | 9篇 |
2017年 | 10篇 |
2016年 | 9篇 |
2015年 | 21篇 |
2014年 | 23篇 |
2013年 | 28篇 |
2012年 | 15篇 |
2011年 | 20篇 |
2010年 | 21篇 |
2009年 | 20篇 |
2008年 | 14篇 |
2007年 | 13篇 |
2006年 | 14篇 |
2005年 | 16篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 12篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 7篇 |
1996年 | 4篇 |
1995年 | 1篇 |
1994年 | 6篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
排序方式: 共有360条查询结果,搜索用时 15 毫秒
141.
双(N┐苯基┐3┐咔唑基)甲苯碘盐的合成李笃信*郭自强兰卫东(山西大学化学系太原030006)关键词苯基咔唑甲苯碘盐,有机光电导体,敏化剂,合成1997-10-27收稿,1998-03-13修回山西省自然科学基金资助项目有机光电导体简称OPC,因其具... 相似文献
142.
细胞色素c在咔唑修饰的金电极上的直接电化学 总被引:4,自引:0,他引:4
在生物体内,细胞色素c是一种电子载体,它能进行可逆的氧化还原反应,但在金属电极上的电化学反应却不可逆。1977年,Hill研究组发现,在4,4′-联吡啶存在时,细胞色素c在金电极上能进行准可逆的电化学反应。4,4′-联吡啶在细胞色素c电化学反应的过程中不起氧化还原反应而被称为促进剂。Hill等对50多种有机化合物的促进作用进行评价后提出,能加速细胞色素c电化学反应速率的促进剂分子至少应具有两个功能团。表面增强拉曼光 相似文献
143.
<正> 为了深入认识含咔唑基单体的光敏性与聚合性的关系,在本系列含咔唑基化合物的基础上,合成了两个新单体:N-(p-羟甲基苯基)咔唑丙烯酸酯和N-(P-羟甲基苯基)咔唑甲基丙烯酸酯,并研究了其聚合行为。 化合物Ⅰ、Ⅱ、Ⅲ和聚合物的合成,反应式如下: 相似文献
144.
145.
A convenient method for the synthesis of ellipticine is reported. This synthesis is achieved by modifying the processes of Woodward and Sainsburg. The overall yield of this five step synthesis is 12 percent. 相似文献
146.
Jin Yin Dr. Peng Chen Le-Wei Miao Prof. Dr. Jie Wang Dr. Yi-Jun Jiang 《European journal of organic chemistry》2023,26(25):e202300290
The first direct and selective 3,6-di-thiolation and 3,6-di-selenylation of carbazoles using diaryl disulfides/diselenide as the sulfur/selenium source were demonstrated. This simple, general, and efficient method could deliver a wide range of 3,6-di-sulfenyl-carbazoles and 3,6-di-selenyl-carbazoles from readily available starting materials with high regioselectivity in an easily-operated one-step reaction via a Ag/K2S2O8-mediated protocol. 相似文献
147.
A series of novel symmetrical carbazole–fluorene–carbazoles has been synthesised using simple and highly efficient reaction pathways. The correlation between their molecular structures, differing in the length of the alkyl chains in the lateral position attached to a 2,7-disubstituted fluorene moiety in the molecular core and/or differing in the length of alkoxy chains at the terminal positions of 2,7-disubstituted carbazole moieties, was investigated. Their mesomorphic behaviour, transition temperatures, energy levels and band gaps were measured. A test organic light-emitting diode incorporating one of these compounds exhibits blue electroluminescence. 相似文献
148.
149.
A. S. Beni M. Zarandi A. R. Madram Y. Bayat A. N. Chermahini R. Ghahary 《Molecular Crystals and Liquid Crystals》2016,629(1):29-43
Carbazole is an alternant polycyclic aromatic hydrocarbon consisting of three fused rings with a large, aromatic system, containing nitrogen atom showing extensive electron delocalization. In this work, carbazole applied as π-conjugated bridge to construct electron donor–π–electron acceptor (D–π–A) organic dyes, where barbutiric acid and thiazolidine-2,4-dione as electron acceptor. The effects of these three acceptors and length of alkyl on the performance of the DSSCs were investigated systematically along with their photophysical and photo electrochemical properties. These series of organic dyes include (B-CH, B-C B, DT-CB, DB-CB). Our investigation indicate among dyes containing butyl as same donor, DT-CB exhibited the maximum overall conversion efficiency of 1.44% and from dyes by deferent electron donor B-CH shows conversion efficiency of 1.47%. 相似文献
150.
Incorporation of different conjugated linkers into low band gap polymers based on 5,6‐Bis(octyloxy)‐2,1,3 benzooxadiazole for tuning optoelectronic properties 下载免费PDF全文
Seza Goker Gonul Hizalan Seda Kutkan Yasemin Arslan Udum Ali Cirpan Levent Toppare 《Journal of polymer science. Part A, Polymer chemistry》2016,54(16):2459-2467
Four new 2,1,3‐benzooxadiazole‐based donor–acceptor conjugated polymers, namely poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSC), poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFC), poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSFL), and poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFFL), were synthesized via Stille polycondensation reaction. All polymers were found to be soluble in common organic solvents such as chloroform, tetrahydrofuran, and chlorobenzene. Their structures were verified by 1H‐NMR and the molecular weights were determined by gel permeation chromatography (GPC). The polymer films exhibited broad absorption bands. Among all polymers, photovoltaic cells based on the device structure of ITO/PEDOT:PSS/PSBSC:PC71BM(1:3, w/w)/LiF/Al revealed an open‐circuit voltage of 0.62 V, a short circuit current of 7.63 mA cm?2 and a power conversion efficiency of 1.89%. This work demonstrates a good example for tuning absorption range, energy level, and photovoltaic properties of the polymers with different spacers and donor units can offer a simple and effective method to improve the efficiency of PSCs. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2459–2467 相似文献