全文获取类型
收费全文 | 221篇 |
免费 | 12篇 |
专业分类
化学 | 145篇 |
晶体学 | 1篇 |
力学 | 8篇 |
数学 | 26篇 |
物理学 | 53篇 |
出版年
2023年 | 1篇 |
2022年 | 3篇 |
2021年 | 6篇 |
2020年 | 6篇 |
2019年 | 2篇 |
2018年 | 7篇 |
2017年 | 8篇 |
2016年 | 11篇 |
2015年 | 11篇 |
2014年 | 14篇 |
2013年 | 15篇 |
2012年 | 14篇 |
2011年 | 16篇 |
2010年 | 20篇 |
2009年 | 10篇 |
2008年 | 15篇 |
2007年 | 9篇 |
2006年 | 14篇 |
2005年 | 8篇 |
2004年 | 5篇 |
2003年 | 10篇 |
2002年 | 6篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1988年 | 1篇 |
排序方式: 共有233条查询结果,搜索用时 109 毫秒
191.
Christoph J. Brabec Serdar N. Sariciftci 《Monatshefte für Chemie / Chemical Monthly》2001,132(4):421-431
Summary. Recent developments on photovoltaic elements based on solid state composites of conjugated, semiconducting polymers mixed
with buckminsterfullerene are reviewed. The photoinduced charge transfer from donor-type semiconducting conjugated polymers
onto acceptor-type conjugated polymers or acceptor molecules such as buckminsterfullerene is reversible, ultrafast (within
100 fs) with a quantum efficiency approaching unity, and the charge separated state is metastable (up to ms at 80 K). This
phenomenon of photoinduced electron transfer leads to a number of potentially interesting applications which include, among
others, sensitization of the photoconductivity, reverse saturable absorption (optical limiting), and photovoltaic phenomena.
Recent studies on the realization of photovoltaic elements with 3% power conversion efficiency are reported.
Received December 19, 2000. Accepted December 22, 2000 相似文献
192.
Serdar Atilgan 《Tetrahedron letters》2004,45(50):9269-9271
The recently reported calixpyridinium tetracation is shown to be very well-suited for anion sensing via the indicator displacement strategy. A very strong binding interaction between the positively charged receptor and the fluorescent pH indicator pyranine (8-hydroxy-1,3,6-pyrenetrisulfonate) requires an anionic guest of comparable negative charge for effective indicator displacement. Thus, selective and sensitive signalling of ATP is achieved in aqueous solutions. 相似文献
193.
A Convenient Synthesis of Bisbenzimidazoles from Iminoester Hydrochlorides Via Microwave Technique
下载免费PDF全文
![点击此处可从《Journal of heterocyclic chemistry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
B. Kahveci E. Menteşe M. Özil F. Yılmaz M. Serdar 《Journal of heterocyclic chemistry》2016,53(3):975-980
A simple and practical method has been developed for the synthesis of bisbenzimidazoles. Iminoester hydrochlorides of phenylacetic acids were used as intermediates in this reaction with 3,3′‐diaminobenzidine under microwave irradiation leading to the products with good yields and in short reaction times. This method can be a general technique for the synthesis of bisbenzimidazoles. 相似文献
194.
Serdar Karademir Oleg A. Prokopyev Robert J. Mailloux 《Journal of Global Optimization》2016,65(2):137-173
A polyomino is a generalization of the domino and is created by connecting a fixed number of unit squares along edges. Tiling a region with a given set of polyominoes is a hard combinatorial optimization problem. This paper is motivated by a recent application of irregular polyomino tilings in the design of phased array antennas. Specifically, we formulate the irregular polyomino tiling problem as a nonlinear exact set covering model, where irregularity is incorporated into the objective function using the information-theoretic entropy concept. An exact solution method based on a branch-and-price framework along with novel branching and lower-bounding schemes is proposed. The developed method is shown to be effective for small- and medium-size instances of the problem. For large-size instances, efficient heuristics and approximation algorithms are provided. Encouraging computational results including phased array antenna simulations are reported. 相似文献
195.
196.
197.
Arif Mermer Serpil Demirci Serap Basoglu Ozdemir Ahmet Demirbas Serdar Ulker Faik Ahmet Ayaz Fatma Aksakal Neslihan Demirbas 《中国化学快报》2017,28(5):995-1005
Azole derivatives(3,6) obtained starting from 1-(2-methoxyphenyl) piperazine were converted to the corresponding Mannich bases containing β-lactame or flouroquinolone core via a one pot three component reaction.The synthesis of conazole analogues was carried out starting from triazoles by three steps.Reactions were carried out under conventional and microwave mediated conditions.All the newly synthesized compounds were screened for their antimicrobial,enzyme inhibition and antioxidant activity,and most of them displayed good-moderate activity.Binding affinities and non-covalent interactions between enzyme-ligand complexes were predicted with molecular docking method at molecular level.Docking results complemented well the experimental results on α-glucosidase and urease inhibitory effects of the compounds.Higher binding affinities and much more interaction networks were observed for active compounds in contrary to inactive ones.It was predicted with the docking studies that triazole and anisole moieties in the structure of the synthesized compounds contributed to the stabilization of corresponding enzymes through noncovalent interactions. 相似文献
198.
199.
Christoph J. Brabec Serdar N. Sariciftci 《Monatshefte für Chemie / Chemical Monthly》2001,22(2):421-431
Recent developments on photovoltaic elements based on solid state composites of conjugated, semiconducting polymers mixed with buckminsterfullerene are reviewed. The photoinduced charge transfer from donor-type semiconducting conjugated polymers onto acceptor-type conjugated polymers or acceptor molecules such as buckminsterfullerene is reversible, ultrafast (within 100 fs) with a quantum efficiency approaching unity, and the charge separated state is metastable (up to ms at 80 K). This phenomenon of photoinduced electron transfer leads to a number of potentially interesting applications which include, among others, sensitization of the photoconductivity, reverse saturable absorption (optical limiting), and photovoltaic phenomena. Recent studies on the realization of photovoltaic elements with 3% power conversion efficiency are reported. 相似文献
200.
The magnetization of Gd diffused YBa2Cu3O7-x is measured by a vibrating sample magnetometer (VSM) at selected temperatures (5, 25, 50, 77 K). The experimental results for the magnetization are analyzed in the critical state framework involving Kim-Anderson field dependence Jc(H)=Jc0/(1+|H|/H0)n of critical current density and equilibrium magnetization M eq . It is found that the inclusion of the equilibrium magnetization becomes more important at higher temperatures. At 77 K, the shape of the isothermal M-H hysteresis curve is governed by the equilibrium magnetization. Some superconducting parameters are determined by fitting the calculated curves to the experimental data. 相似文献