全文获取类型
收费全文 | 182971篇 |
免费 | 7163篇 |
国内免费 | 5676篇 |
专业分类
化学 | 85400篇 |
晶体学 | 2204篇 |
力学 | 12516篇 |
综合类 | 368篇 |
数学 | 44174篇 |
物理学 | 51148篇 |
出版年
2023年 | 907篇 |
2022年 | 1957篇 |
2021年 | 2328篇 |
2020年 | 2628篇 |
2019年 | 2792篇 |
2018年 | 13219篇 |
2017年 | 12954篇 |
2016年 | 9752篇 |
2015年 | 3570篇 |
2014年 | 4186篇 |
2013年 | 5817篇 |
2012年 | 9482篇 |
2011年 | 16325篇 |
2010年 | 10226篇 |
2009年 | 10590篇 |
2008年 | 11441篇 |
2007年 | 13278篇 |
2006年 | 4462篇 |
2005年 | 5045篇 |
2004年 | 4782篇 |
2003年 | 4838篇 |
2002年 | 4022篇 |
2001年 | 2959篇 |
2000年 | 2441篇 |
1999年 | 1897篇 |
1998年 | 1864篇 |
1997年 | 1577篇 |
1996年 | 1588篇 |
1995年 | 1318篇 |
1994年 | 1336篇 |
1993年 | 1265篇 |
1992年 | 1186篇 |
1991年 | 1255篇 |
1990年 | 1234篇 |
1989年 | 1129篇 |
1988年 | 1018篇 |
1987年 | 1005篇 |
1986年 | 973篇 |
1985年 | 996篇 |
1984年 | 979篇 |
1983年 | 867篇 |
1982年 | 861篇 |
1979年 | 852篇 |
1978年 | 856篇 |
1977年 | 832篇 |
1976年 | 942篇 |
1975年 | 835篇 |
1974年 | 861篇 |
1973年 | 875篇 |
1972年 | 769篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Theoretical and Mathematical Physics - We consider three one-dimensional superconducting structures: 1) the one with $$p$$ -wave superconductivity; 2) the main experimental model of a nanowire with... 相似文献
2.
Siberian Mathematical Journal - We give a simple proof of one assertion used in solving Waring’s problem. 相似文献
3.
4.
Journal of Fourier Analysis and Applications - We develop a theory of Sobolev orthogonal polynomials on the Sierpiński gasket ( $$SG$$ ), which is a fractal set that can be viewed as a limit... 相似文献
5.
Journal of Applied and Industrial Mathematics - We study the problem of optimal location of the ambulance fleet at the base stations. The objective is to minimize the average waiting time for... 相似文献
6.
Dr. Yong-Sheng Wei Dr. Liming Sun Miao Wang Dr. Jinhua Hong Dr. Lianli Zou Hongwen Liu Dr. Yu Wang Dr. Mei Zhang Dr. Zheng Liu Prof. Yinwei Li Prof. Satoshi Horike Prof. Kazu Suenaga Prof. Qiang Xu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(37):16147-16156
Understanding the thermal aggregation behavior of metal atoms is important for the synthesis of supported metal clusters. Here, derived from a metal–organic framework encapsulating a trinuclear FeIII2FeII complex (denoted as Fe3) within the channels, a well-defined nitrogen-doped carbon layer is fabricated as an ideal support for stabilizing the generated iron nanoclusters. Atomic replacement of FeII by other metal(II) ions (e.g., ZnII/CoII) via synthesizing isostructural trinuclear-complex precursors (Fe2Zn/Fe2Co), namely the “heteroatom modulator approach”, is inhibiting the aggregation of Fe atoms toward nanoclusters with formation of a stable iron dimer in an optimal metal–nitrogen moiety, clearly identified by direct transmission electron microscopy and X-ray absorption fine structure analysis. The supported iron dimer, serving as cooperative metal–metal site, acts as efficient oxygen evolution catalyst. Our findings offer an atomic insight to guide the future design of ultrasmall metal clusters bearing outstanding catalytic capabilities. 相似文献
7.
Kang Il Yoo Ji Yeong Jeon Su Jeong Ryu Giri Nam Hyewon Youn Eun Young Choi 《Experimental & molecular medicine》2015,47(2):e140
In allogeneic transplantation, including the B6 anti-BALB.B settings, H60 and H4 are two representative dominant minor histocompatibility antigens that induce strong CD8 T-cell responses. With different distribution patterns, H60 expression is restricted to hematopoietic cells, whereas H4 is ubiquitously expressed. H60-specific CD8 T-cell response has been known to be dominant in most cases of B6 anti-BALB.B allo-responses, except in the case of skin transplantation. To understand the mechanism underlying the subdominance of H60 during allogeneic skin transplantation, we investigated the dynamics of the H60-specific CD8 T cells in B6 mice transplanted with allogeneic BALB.B tail skin. Unexpectedly, longitudinal bioluminescence imaging and flow cytometric analyses revealed that H60-specific CD8 T cells were not always subdominant to H4-specific cells but instead showed a brief dominance before the H4 response became predominant. H60-specific CD8 T cells could expand in the draining lymph node and migrate to the BALB.B allografts, indicating their active participation in the anti-BALB.B allo-response. Enhancing the frequencies of H60-reactive CD8 T cells prior to skin transplantation reversed the immune hierarchy between H60 and H4. Additionally, H60 became predominant when antigen presentation was limited to the direct pathway. However, when antigen presentation was restricted to the indirect pathway, the expansion of H60-specific CD8 T cells was limited, whereas H4-specific CD8 T cells expanded significantly, suggesting that the temporary immunodominance and eventual subdominance of H60 could be due to their reliance on the direct antigen presentation pathway. These results enhance our understanding of the immunodominance phenomenon following allogeneic tissue transplantation. 相似文献
8.
9.
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
10.
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