全文获取类型
收费全文 | 128078篇 |
免费 | 1748篇 |
国内免费 | 473篇 |
专业分类
化学 | 70990篇 |
晶体学 | 2068篇 |
力学 | 5005篇 |
综合类 | 5篇 |
数学 | 12363篇 |
物理学 | 39868篇 |
出版年
2016年 | 1412篇 |
2015年 | 1084篇 |
2014年 | 1471篇 |
2013年 | 4990篇 |
2012年 | 3655篇 |
2011年 | 4675篇 |
2010年 | 2904篇 |
2009年 | 2673篇 |
2008年 | 4143篇 |
2007年 | 4182篇 |
2006年 | 4204篇 |
2005年 | 4121篇 |
2004年 | 3630篇 |
2003年 | 3268篇 |
2002年 | 3185篇 |
2001年 | 3622篇 |
2000年 | 2749篇 |
1999年 | 2232篇 |
1998年 | 1901篇 |
1997年 | 1886篇 |
1996年 | 1823篇 |
1995年 | 1793篇 |
1994年 | 1562篇 |
1993年 | 1549篇 |
1992年 | 1785篇 |
1991年 | 1761篇 |
1990年 | 1682篇 |
1989年 | 1691篇 |
1988年 | 1689篇 |
1987年 | 1680篇 |
1986年 | 1594篇 |
1985年 | 2152篇 |
1984年 | 2269篇 |
1983年 | 1891篇 |
1982年 | 2218篇 |
1981年 | 2038篇 |
1980年 | 2081篇 |
1979年 | 2064篇 |
1978年 | 2192篇 |
1977年 | 2099篇 |
1976年 | 2120篇 |
1975年 | 2060篇 |
1974年 | 1906篇 |
1973年 | 2105篇 |
1972年 | 1283篇 |
1971年 | 977篇 |
1970年 | 912篇 |
1969年 | 923篇 |
1968年 | 1052篇 |
1967年 | 1101篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
31.
Andrew W. Sale 《Geometriae Dedicata》2015,176(1):305-313
32.
Kinetics and Catalysis - A series of Cu-SSZ-13@CeO2 catalysts with surface modification with CeO2 was prepared by the modified self-resemble method based on the one-pot synthesized Cu-SSZ-13... 相似文献
33.
34.
35.
Sajeesh Kumar Madhurakkat Perikamana Sang Min Lee Jinkyu Lee Taufiq Ahmad Min Suk Lee Hee Seok Yang Heungsoo Shin 《Macromolecular bioscience》2019,19(4)
Plant derived flavonoids have not been well explored in tissue engineering applications due to difficulties in efficient formulations with biomaterials for controlled presentation. Here, the authors report that surface coating of epigallocatechin gallate (EGCG) on polymeric substrates including poly (L‐lactic acid) (PLLA) nanofibers can be performed via oxidative polymerization of EGCG in the presence of cations, enabling regulation of biological functions of multiple cell types implicated in bone regeneration. EGCG coating on the PLLA nanofiber promotes osteogenic differentiation of adipose‐derived stem cells (ADSCs) and is potent to suppress adipogenesis of ADSCs while significantly reduces osteoclastic maturation of murine macrophages. Moreover, EGCG coating serves as a protective layer for ADSCs against oxidative stress caused by hydrogen peroxide. Finally, the in vivo implantation of EGCG‐coated nanofibers into a mouse calvarial defect model significantly promotes the bone regeneration (61.52 ± 28.10%) as compared to defect (17.48 ± 11.07%). Collectively, the results suggest that EGCG coating is a simple bioinspired surface modification of polymeric biomaterials and importantly can thus serve as a promising interface for tuning activities of multiple cell types associated with bone fracture healing. 相似文献
36.
Gas-phase 21Ne nuclear magnetic resonance spectra were measured at the natural abundance of 21Ne isotope for samples consisting of pressurized neon up to 60 bar at room temperature and applying the magnetic field of the strength B0 = 11.7574 T. It showed that the nuclear magnetic resonance frequency is linearly dependent on the density of gaseous neon. The resonance frequency was extrapolated to the zero-density point, and it permitted the determination of the 21Ne nuclear magnetic moment, μ(21Ne) = 0.6617774(10) μN. The present value of μ(21Ne) is not influenced by the bulk magnetic susceptibility of neon and interactions between neon atoms; therefore, it is more precise and reliable than the previous result obtained for μ(21Ne). 相似文献
37.
38.
39.