全文获取类型
收费全文 | 1698篇 |
免费 | 64篇 |
国内免费 | 9篇 |
专业分类
化学 | 785篇 |
晶体学 | 20篇 |
力学 | 78篇 |
数学 | 289篇 |
物理学 | 599篇 |
出版年
2023年 | 16篇 |
2022年 | 15篇 |
2021年 | 39篇 |
2020年 | 42篇 |
2019年 | 52篇 |
2018年 | 49篇 |
2017年 | 45篇 |
2016年 | 76篇 |
2015年 | 47篇 |
2014年 | 75篇 |
2013年 | 105篇 |
2012年 | 119篇 |
2011年 | 141篇 |
2010年 | 108篇 |
2009年 | 86篇 |
2008年 | 75篇 |
2007年 | 98篇 |
2006年 | 55篇 |
2005年 | 67篇 |
2004年 | 41篇 |
2003年 | 40篇 |
2002年 | 27篇 |
2001年 | 16篇 |
2000年 | 19篇 |
1999年 | 19篇 |
1998年 | 10篇 |
1997年 | 13篇 |
1996年 | 28篇 |
1995年 | 18篇 |
1994年 | 13篇 |
1993年 | 21篇 |
1992年 | 10篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 7篇 |
1986年 | 10篇 |
1985年 | 14篇 |
1984年 | 13篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1981年 | 14篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1978年 | 8篇 |
1977年 | 8篇 |
1976年 | 7篇 |
1974年 | 6篇 |
1973年 | 6篇 |
排序方式: 共有1771条查询结果,搜索用时 15 毫秒
1.
Geometriae Dedicata - Given a finite graph of relatively hyperbolic groups with its fundamental group relatively hyperbolic and edge groups quasi-isometrically embedded and relatively quasiconvex... 相似文献
2.
Das Pritam Kumar Mallik Arnab Kumar Molla Altaf Hossain Santra Apurba Kumar Ganguly Ranjan Saha Abhijit Kumar Sugam Aswal V. K. 《Journal of Thermal Analysis and Calorimetry》2022,147(10):5617-5635
Journal of Thermal Analysis and Calorimetry - Nanofluids have gained recent attention because of their potential applications in diverse engineering fields like enhancing thermal transport,... 相似文献
3.
Siddhartha Biswas 《Waves in Random and Complex Media》2020,30(4):759-775
ABSTRACT The article deals with the study of plane wave propagation in the thermoelastic medium in the presence of voids. The problem is considered in the context of three-phase-lag model of generalized thermoelasticity. There exists three longitudinal waves, namely elastic (E-mode), thermal (T-mode) and volume fraction (V-mode) in addition to transverse waves which get decoupled from the rest of motion and not affected by thermal and volume fraction fields. The fundamental solution of the system of differential equations in case of steady oscillations in terms of the elementary functions has been constructed. The phase velocity and attenuation coefficient of these waves are computed numerically and presented graphically. 相似文献
4.
5.
6.
7.
8.
Raghida Bou Zerdan Zhishuai Geng Benjaporn Narupai Yvonne J. Diaz Morgan W. Bates David S. Laitar Biswas Souvagya Antony K. Van Dyk Craig J. Hawker 《Journal of polymer science. Part A, Polymer chemistry》2020,58(14):1989-1997
The utility of pentafluorophenyl esters for the selective introduction of functional units and branch points in well-defined poly(acrylic acid) (PAA) derivatives is demonstrated using a combination of controlled radical polymerization and postpolymerization modification. Reversible addition-fragmentation chain transfer enables the synthesis of well-defined copolymers—poly(pentafluorophenyl acrylate-co-tert-butyl acrylate)—with the active ester repeat units serving as attachment points for reaction with primary amines, specifically tris(2-(t-butoxycarbonyl)ethyl)methyl amine (Behera's amine). Deprotection using trifluoroacetic acid removes both the backbone and side chain t-butyl esters to give a series of branched PAA derivatives containing novel tricarboxylic acid side chains that are well suited to complexation and multidentate interactions. Surprisingly, the active ester homopolymer is shown to have the highest reactivity with Behera's amine when compared to copolymers with lower incorporation of pentafluorophenyl esters, suggesting an intriguing interplay of neighboring group effects and steric interactions. The ability to tune the efficiency of postpolymerization modification gives a library of PAA derivatives. 相似文献
9.
Nonlinear Dynamics - Phase-shift controlling can attenuate the interactions between solitons and gives practical advantage in optical communication systems. For the variable-coefficient nonlinear... 相似文献
10.
Structural Chemistry - The role of Ti(II) sandwich complex, [Cp2Ti], generated by the combination of [Cp2TiCl2] and two equivalents of nBuLi, in situ, in toluene has been investigated theoretically... 相似文献