全文获取类型
收费全文 | 116825篇 |
免费 | 9091篇 |
国内免费 | 8027篇 |
专业分类
化学 | 69178篇 |
晶体学 | 1699篇 |
力学 | 6804篇 |
综合类 | 564篇 |
数学 | 14059篇 |
物理学 | 41639篇 |
出版年
2023年 | 1092篇 |
2022年 | 2477篇 |
2021年 | 2794篇 |
2020年 | 3103篇 |
2019年 | 3320篇 |
2018年 | 3618篇 |
2017年 | 3578篇 |
2016年 | 4383篇 |
2015年 | 3413篇 |
2014年 | 4606篇 |
2013年 | 6318篇 |
2012年 | 6731篇 |
2011年 | 7028篇 |
2010年 | 5475篇 |
2009年 | 5650篇 |
2008年 | 5873篇 |
2007年 | 5379篇 |
2006年 | 4927篇 |
2005年 | 4308篇 |
2004年 | 3755篇 |
2003年 | 3224篇 |
2002年 | 3323篇 |
2001年 | 3007篇 |
2000年 | 2414篇 |
1999年 | 1948篇 |
1998年 | 1773篇 |
1997年 | 1564篇 |
1996年 | 1492篇 |
1995年 | 1271篇 |
1994年 | 1309篇 |
1993年 | 1234篇 |
1992年 | 1189篇 |
1991年 | 1219篇 |
1990年 | 1200篇 |
1989年 | 1097篇 |
1988年 | 973篇 |
1987年 | 959篇 |
1986年 | 922篇 |
1985年 | 956篇 |
1984年 | 936篇 |
1983年 | 848篇 |
1982年 | 809篇 |
1979年 | 815篇 |
1978年 | 816篇 |
1977年 | 810篇 |
1976年 | 920篇 |
1975年 | 818篇 |
1974年 | 849篇 |
1973年 | 848篇 |
1972年 | 753篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
Knyazev A. A. Karyakin M. E. Krupin A. S. Galyametdinov Yu. G. 《Russian Journal of General Chemistry》2015,85(12):2806-2812
Russian Journal of General Chemistry - Hybrid liquid crystal systems with different ratios of the components have been prepared on the basis of 5,5′-di(heptadecyl)-2,2′-bipyridine... 相似文献
4.
Jing Zhihong Ling Baoping Yu Yang Qi Wei Zhang Shufang 《Journal of Sol-Gel Science and Technology》2015,73(1):112-117
Journal of Sol-Gel Science and Technology - A novel gas sensing material, La–Y co-doped TiO2 nanoparticles, was synthesized by sol–gel method and applied to detect organic pollutants... 相似文献
5.
6.
7.
An approach of dynamic mesh adaptation for simulating 3‐dimensional unsteady moving‐immersed‐boundary flows 下载免费PDF全文
In this paper, we present an approach of dynamic mesh adaptation for simulating complex 3‐dimensional incompressible moving‐boundary flows by immersed boundary methods. Tetrahedral meshes are adapted by a hierarchical refining/coarsening algorithm. Regular refinement is accomplished by dividing 1 tetrahedron into 8 subcells, and irregular refinement is only for eliminating the hanging points. Merging the 8 subcells obtained by regular refinement, the mesh is coarsened. With hierarchical refining/coarsening, mesh adaptivity can be achieved by adjusting the mesh only 1 time for each adaptation period. The level difference between 2 neighboring cells never exceeds 1, and the geometrical quality of mesh does not degrade as the level of adaptive mesh increases. A predictor‐corrector scheme is introduced to eliminate the phase lag between adapted mesh and unsteady solution. The error caused by each solution transferring from the old mesh to the new adapted one is small because most of the nodes on the 2 meshes are coincident. An immersed boundary method named local domain‐free discretization is employed to solve the flow equations. Several numerical experiments have been conducted for 3‐dimensional incompressible moving‐boundary flows. By using the present approach, the number of mesh nodes is reduced greatly while the accuracy of solution can be preserved. 相似文献
8.
9.
10.
V. A. Bespalov V. M. Glazov E. A. Il’ichev Yu. A. Klimov S. V. Kuklev A. E. Kuleshov R. M. Nabiev G. N. Petrukhin B. G. Potapov G. S. Rychkov D. S. Sokolov V. V. Fandeev E. A. Fetisov S. S. Yakushov 《Technical Physics》2015,60(4):553-560
The results of investigation of optical image detectors designed for the largest problem, near-VUV, range of the spectrum are presented. The possibility of using a dual-stage image detection system to appreciably lower the sensitivity threshold and make computer data processing feasible is considered. The integration of a UV module into a wideband image detector is studied. 相似文献