全文获取类型
收费全文 | 4033篇 |
免费 | 689篇 |
国内免费 | 335篇 |
专业分类
化学 | 2631篇 |
晶体学 | 54篇 |
力学 | 296篇 |
综合类 | 17篇 |
数学 | 400篇 |
物理学 | 1659篇 |
出版年
2024年 | 16篇 |
2023年 | 109篇 |
2022年 | 144篇 |
2021年 | 176篇 |
2020年 | 162篇 |
2019年 | 158篇 |
2018年 | 159篇 |
2017年 | 123篇 |
2016年 | 217篇 |
2015年 | 201篇 |
2014年 | 229篇 |
2013年 | 310篇 |
2012年 | 383篇 |
2011年 | 368篇 |
2010年 | 248篇 |
2009年 | 215篇 |
2008年 | 240篇 |
2007年 | 224篇 |
2006年 | 215篇 |
2005年 | 179篇 |
2004年 | 130篇 |
2003年 | 104篇 |
2002年 | 82篇 |
2001年 | 73篇 |
2000年 | 82篇 |
1999年 | 69篇 |
1998年 | 66篇 |
1997年 | 52篇 |
1996年 | 56篇 |
1995年 | 52篇 |
1994年 | 28篇 |
1993年 | 41篇 |
1992年 | 39篇 |
1991年 | 23篇 |
1990年 | 21篇 |
1989年 | 15篇 |
1988年 | 11篇 |
1987年 | 7篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 1篇 |
1983年 | 6篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有5057条查询结果,搜索用时 32 毫秒
951.
Duan Yiwu 《中国物理C(英文版)》1995,19(1):59-63
A new effective interaction between a neutron and the 9Li core is introduced, and based on the n+n+9Li model, a variational calculation on the neutron rich nucleus 11Li is completed. The one-body density, formfactor and shapedensity are investigated, The RMS radius and the binding energy are also calculated and are in good agreement with the experimental data. 相似文献
952.
Qi Duan Gongxue Xu Aikui Liu Xuefu Wang Fuhua Cheng 《Journal of Applied Mathematics and Computing》1999,6(1):203-215
In this paper, a rational cubic interpolant spline with linear denominator has been constructed, and it is used to constrain interpolation curves to be bounded in the given region. Necessary and sufficient conditions for the interpolant to satisfy the constraint have been developed. The existence conditions are computationally efficient and easy to apply. Finally, the approximation properties have been studied. 相似文献
953.
In Einstein-Cartan theory, by the use of thegeneral Noether theorem, the general covariantangular-momentum conservation law is obtained withrespect to the local Lorentz transformations. Thecorresponding conservative Noether current is interpreted asthe angular momentum tensor of the gravity-matter systemincluding the spin density. It is pointed out that,assuming the tetrad transformation given by eq. (15), then torsion does not play a role in theconservation law of angular momentum. 相似文献
954.
A splitting of a third order partial differential equation into a first-order and a second-order one is proposed as the basis for a mixed finite element method to approximate its solution. A time-continuous numerical method is described and error estimates for its solution are demonstrated. Finally, a full discretization is described based on backward Euler finite differences in time, and error estimates for the resulting approximation are established. © 1998 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 14: 89–96, 1998 相似文献
955.
Despite the success of monochromatic hyperfluorescent (HF) organic light-emitting diodes (OLEDs), high-efficiency HF white OLEDs (WOLEDs) are still a big challenge. Herein, we demonstrate HF WOLEDs with state-of-the-art efficiencies, featuring a quasi-bilayer emissive layer (EML) composed of an ultrathin (0.1 nm) blue fluorescence (FL) emitter (TBPe) layer and a layer of thermally activated delayed fluorescence (TADF) sensitizer matrix heavily doped with a yellow FL emitter (TBRb, 3%). Based on an asymmetric high-energy-gap TADF sensitizer host (PhCzSPOTz), such an “ultrathin blue emitting layer (UTBL)” strategy endowed the HF WOLEDs with a record power efficiency of ∼80 lm W−1, approaching the level of fluorescent tubes. Transient photoluminescence (PL) and electroluminescence (EL) kinetics demonstrate that the spatial separation of TBPe from the TADF sensitizer and TBRb, and the large energy gap between the latter two effectively suppress triplet leakage, in addition to suppressing triplet diffusion in the PhCzSPOTz matrix with anisotropic intermolecular interactions. These results provide a new insight into the exciton allocation process in HF white light-emitting systems.A thermally activated delayed fluorescence host was developed to realize high-efficiency fluorescence white organic light-emitting diodes (WOLED) through spatial and energy gap effects. 相似文献
956.
957.
958.
959.
960.