全文获取类型
收费全文 | 84872篇 |
免费 | 767篇 |
国内免费 | 480篇 |
专业分类
化学 | 29322篇 |
晶体学 | 842篇 |
力学 | 6882篇 |
综合类 | 4篇 |
数学 | 32474篇 |
物理学 | 16595篇 |
出版年
2023年 | 59篇 |
2022年 | 107篇 |
2021年 | 162篇 |
2020年 | 154篇 |
2019年 | 186篇 |
2018年 | 10512篇 |
2017年 | 10335篇 |
2016年 | 6300篇 |
2015年 | 1070篇 |
2014年 | 586篇 |
2013年 | 755篇 |
2012年 | 4266篇 |
2011年 | 11036篇 |
2010年 | 5996篇 |
2009年 | 6347篇 |
2008年 | 7033篇 |
2007年 | 9097篇 |
2006年 | 630篇 |
2005年 | 1687篇 |
2004年 | 1831篇 |
2003年 | 2219篇 |
2002年 | 1264篇 |
2001年 | 403篇 |
2000年 | 419篇 |
1999年 | 234篇 |
1998年 | 259篇 |
1997年 | 220篇 |
1996年 | 273篇 |
1995年 | 174篇 |
1994年 | 126篇 |
1993年 | 164篇 |
1992年 | 102篇 |
1991年 | 108篇 |
1990年 | 94篇 |
1989年 | 109篇 |
1988年 | 92篇 |
1987年 | 90篇 |
1986年 | 90篇 |
1985年 | 80篇 |
1984年 | 67篇 |
1983年 | 60篇 |
1982年 | 62篇 |
1981年 | 66篇 |
1980年 | 68篇 |
1979年 | 65篇 |
1978年 | 46篇 |
1914年 | 45篇 |
1912年 | 40篇 |
1909年 | 41篇 |
1908年 | 40篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Christiane Albrecht 《Analytical and bioanalytical chemistry》2008,390(5):1223-1224
5.
6.
Chengzhi Qi Mingyang Wang Qihu Qian Jianjie Chen 《Moscow University Mechanics Bulletin》2008,63(5):113-121
The formation mechanisms for the structural hierarchy in geological media are discussed. It is shown that the formation of such a hierarchy is caused by certain external and internal circumstances. The first ones consist in the fact that, because of external actions, the Earth’s poles continuously execute the translational and rotational motions responsible for a regular structure of rock fracture and for the appearance of the scale factor √2. The second ones consist in the fact that, under the action of many random factors and because of external actions, during the formation of geological media there appear dissipative structures and, hence, some self-similar fractal structures are formed. 相似文献
7.
Howard Robinson 《Acta Analytica》2005,20(3):7-10
Nicholas Nathan tries to resist the current version of the causal argument for sense-data in two ways. First he suggests that,
on what he considers to be the correct re-construction of the argument, it equivocates on the sense of proximate cause. Second
he defends a form of disjunctivism, by claiming that there might be an extra mechanism involved in producing veridical hallucination,
that is not present in perception. I argue that Nathan’s reconstruction of the argument is not the appropriate one, and that,
properly interpreted, the argument does not equivocate on proximate cause. Furthermore, I claim that his postulation of a
modified mechanism for hallucinations is implausibly ad hoc. 相似文献
8.
9.
Dong‐Guk Yu Jeong Ho An 《Journal of polymer science. Part A, Polymer chemistry》2004,42(22):5608-5616
Ultrafine black particles, ranging in diameter from 1 to 3 μm, were prepared by dispersion polymerization in a methanol/water mixture with vinyl monomers, nonpolymerizable Sudan black B dyes, and fluorescein isothiocyanate labeled charge control additives. Both the ratio of the methanol to the water dispersion medium and the polymeric stabilizer concentration had significant effects on the particle size. The important role of the stabilizer concentration lay in the particle formation step, during which it determined the particle stability and final particle size. These could affect the extent of the aggregation of nuclei by changing the adsorption rate of the stabilizer and the viscosity of the dispersion medium, resulting in smaller particles. The fluorescent‐labeled charge control additives strongly affected the electrophoretic mobility. A small concentration of fluorescent‐labeled charge control additives increased the electrophoretic mobility. However, a further addition reduced the electrophoretic mobility of the polymer particles. The concentration dependence of the fluorescent‐labeled charge control additives on the deposition behavior in the polymer particles was successfully imaged and thereafter quantified by image analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5608–5616, 2004 相似文献
10.