全文获取类型
收费全文 | 10353篇 |
免费 | 430篇 |
国内免费 | 87篇 |
专业分类
化学 | 7115篇 |
晶体学 | 97篇 |
力学 | 269篇 |
综合类 | 1篇 |
数学 | 1746篇 |
物理学 | 1642篇 |
出版年
2023年 | 77篇 |
2022年 | 78篇 |
2021年 | 192篇 |
2020年 | 209篇 |
2019年 | 250篇 |
2018年 | 160篇 |
2017年 | 159篇 |
2016年 | 388篇 |
2015年 | 288篇 |
2014年 | 321篇 |
2013年 | 604篇 |
2012年 | 609篇 |
2011年 | 655篇 |
2010年 | 454篇 |
2009年 | 406篇 |
2008年 | 587篇 |
2007年 | 631篇 |
2006年 | 497篇 |
2005年 | 547篇 |
2004年 | 443篇 |
2003年 | 352篇 |
2002年 | 338篇 |
2001年 | 162篇 |
2000年 | 145篇 |
1999年 | 96篇 |
1998年 | 104篇 |
1997年 | 110篇 |
1996年 | 114篇 |
1995年 | 93篇 |
1994年 | 85篇 |
1993年 | 101篇 |
1992年 | 79篇 |
1991年 | 80篇 |
1990年 | 75篇 |
1989年 | 64篇 |
1988年 | 51篇 |
1987年 | 55篇 |
1986年 | 70篇 |
1985年 | 103篇 |
1984年 | 101篇 |
1983年 | 80篇 |
1982年 | 69篇 |
1981年 | 74篇 |
1980年 | 68篇 |
1979年 | 64篇 |
1978年 | 69篇 |
1977年 | 41篇 |
1976年 | 41篇 |
1975年 | 50篇 |
1974年 | 55篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
991.
992.
993.
994.
995.
In this paper we show that the unit ball of an infinite dimensional function algebra has no strongly exposed points.
996.
997.
The cerebral involvement of a 13-yr-old boy with Wilson's disease was serially evaluated during the first 18 mo of D-penicillamine treatment. An ultra-low-field magnetic resonance imaging (ULF MRI) system, operating at 0.02 T, with computerized image processing was used. The half-yr period prior to the clinical diagnosis was set, the patient had showed poor school performance, emotional lability, deteriorating handwriting, progressively slow, gross, and fine motor functions, and a fixed rigid smile. No overt signs of liver disease were found. With D-penicillamine treatment (1–1.5 g/d) a continuous improvement was seen. The pretreatment MRI investigation showed pronounced pathological transformation in the basal ganglia. However, changes were seen also in most other parts of the brain indicating diffuse involvement. During treatment the computerized MR images became gradually more normal. The current magnetic resonance imaging system with computerized image processing is a sensitive and simple method for evaluation of subtle parenchymal changes of the brain. 相似文献
998.
999.
1000.
The influence of macro-scale heterogeneities on the imbibition process is investigated for Savonnières, a French layered limestone. Free uptake experiments are performed both parallel and perpendicular to the bedding. It is found that the position of the different layers, and the exact material properties inside each layer can significantly influence the imbibition process. The experimental results are compared with numerical simulations. For the flow simulations, moisture permeability of the different layers is obtained with the upscaling technique presented in Part 1. Good agreement between simulations and experiments validate the proposed upscaling from meso to macroscopic scale. 相似文献