全文获取类型
收费全文 | 1303篇 |
免费 | 66篇 |
国内免费 | 4篇 |
专业分类
化学 | 742篇 |
晶体学 | 25篇 |
力学 | 48篇 |
数学 | 211篇 |
物理学 | 220篇 |
无线电 | 127篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 23篇 |
2021年 | 46篇 |
2020年 | 47篇 |
2019年 | 38篇 |
2018年 | 36篇 |
2017年 | 51篇 |
2016年 | 58篇 |
2015年 | 61篇 |
2014年 | 53篇 |
2013年 | 128篇 |
2012年 | 107篇 |
2011年 | 113篇 |
2010年 | 88篇 |
2009年 | 66篇 |
2008年 | 83篇 |
2007年 | 68篇 |
2006年 | 44篇 |
2005年 | 48篇 |
2004年 | 52篇 |
2003年 | 25篇 |
2002年 | 29篇 |
2001年 | 8篇 |
2000年 | 13篇 |
1999年 | 6篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 3篇 |
1992年 | 4篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1986年 | 1篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1972年 | 3篇 |
1907年 | 1篇 |
排序方式: 共有1373条查询结果,搜索用时 500 毫秒
41.
Mert Mehmet Selçuk Mert Hatice Hande Sert Merve 《Journal of Thermal Analysis and Calorimetry》2019,136(4):1551-1561
Journal of Thermal Analysis and Calorimetry - Thermal energy storage systems provide efficiency in order to have better utilization of energy sources while protecting the environment. Thermal... 相似文献
42.
In the present work, according to the concept of extended homogeneous balance method and with help of Maple, we get auto-Bäcklund transformations for a (2 + 1)-dimensional nonlinear evolution equation. Subsequently, by using these auto-Bäcklund transformation, exact explicit solutions of this equation are obtained. 相似文献
43.
Electroinitiated polymerization of N-vinylcarbazole has been accomplished by constant potential electrolysis. It was found that direct electron transfer from the monomer to the anode initiates the polymerization even at a potential as low as +0.95 V versus Ag?/ Ag+. Dichloromethane was used as the solvent, and the electrolyte was tetrabutylammonium fluoroborate. Conversions as high as 86% were reached even when a microelectrode was used. Effects of electrode area, temperature, and electrode potential on polymerization were studied. Percent conversion was followed by cyclic voltammetry. 相似文献
44.
45.
Journal of Inclusion Phenomena and Macrocyclic Chemistry - Newly phthalocyanine derivative which carries 2,6-dimethoxyphenoxy bioactive groups as tetrakis from non-peripheral positions of the... 相似文献
46.
47.
Ersan Ronak Haj Alagoz Mehmet Abdullah Ertan-Bolelli Tugba Duran Nizami Burmaoglu Serdar Algul Oztekin 《Molecular diversity》2021,25(4):2247-2259
Molecular Diversity - In the present work, a series of bisbenzazole derivatives were designed and synthesized as antiproliferative agents. The antiproliferative activity of these compounds was... 相似文献
48.
We obtained the azo‐imine ligand (2,2′‐[4‐(5‐methoxy salicylidene‐4‐iminophenylazo)phenylimino]diethanol) (HL) and its Cu (II) complex (CuL) from the ethanol solution. The complex Cu(L)2 was obtained as single crystals from the CH3OH solution and structurally characterized. The electronic and photoluminescence properties of the ligand and its Cu (II) complex were investigated both in DMF solution and solid state. The oxidation and reduction behaviours of the compounds were studied in the solution and found that the redox processes are irreversible. Thermal studies show that the ligand has higher thermal stability than the CuL complex. Single crystals of the complex were obtained from slow evaporation of a DMF solution of the complex. Crystals of the complex showed a diffraction pattern; however, the structure of the complex was able to be solved. 相似文献
49.
Positivity - In this paper we investigate the distance of convergence in measure whenever the measure is not $$\sigma $$ -finite and identify the topological coreflection of this approach structure... 相似文献
50.