全文获取类型
收费全文 | 77016篇 |
免费 | 15940篇 |
国内免费 | 7851篇 |
专业分类
化学 | 71695篇 |
晶体学 | 1035篇 |
力学 | 2623篇 |
综合类 | 549篇 |
数学 | 7070篇 |
物理学 | 17835篇 |
出版年
2024年 | 149篇 |
2023年 | 787篇 |
2022年 | 1583篇 |
2021年 | 1754篇 |
2020年 | 2835篇 |
2019年 | 4076篇 |
2018年 | 2431篇 |
2017年 | 2209篇 |
2016年 | 5217篇 |
2015年 | 5480篇 |
2014年 | 5907篇 |
2013年 | 7168篇 |
2012年 | 6812篇 |
2011年 | 6247篇 |
2010年 | 5823篇 |
2009年 | 5614篇 |
2008年 | 5370篇 |
2007年 | 4518篇 |
2006年 | 4020篇 |
2005年 | 3660篇 |
2004年 | 2999篇 |
2003年 | 2604篇 |
2002年 | 3311篇 |
2001年 | 2427篇 |
2000年 | 2150篇 |
1999年 | 1200篇 |
1998年 | 654篇 |
1997年 | 525篇 |
1996年 | 488篇 |
1995年 | 419篇 |
1994年 | 390篇 |
1993年 | 312篇 |
1992年 | 266篇 |
1991年 | 273篇 |
1990年 | 198篇 |
1989年 | 178篇 |
1988年 | 120篇 |
1987年 | 110篇 |
1986年 | 110篇 |
1985年 | 101篇 |
1984年 | 42篇 |
1983年 | 33篇 |
1982年 | 32篇 |
1981年 | 20篇 |
1980年 | 20篇 |
1979年 | 17篇 |
1978年 | 13篇 |
1959年 | 13篇 |
1958年 | 11篇 |
1957年 | 20篇 |
排序方式: 共有10000条查询结果,搜索用时 27 毫秒
1.
2.
Lin Yu Wu Yeyu Tan Xuecai Wu Jiawen Huang Kejing Mi Yan Ou Panpan Wei Fucun 《Journal of Solid State Electrochemistry》2022,26(4):959-971
Journal of Solid State Electrochemistry - An ultrasensitive “signal-off–on” electrochemiluminescence (ECL) biosensor is constructed based on f1-TiO2/g-C3N4/PDA for thrombin... 相似文献
3.
Tian Jie Yang Weifeng Chen Min Zheng Minfang Chen Ding Qiu Yusheng 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(2):1039-1049
Journal of Radioanalytical and Nuclear Chemistry - This study presents a time-efficient method of analysing 210Pb, 210Bi, and 210Po in natural waters. The optimum pH (1.00), temperature... 相似文献
4.
5.
A numerical model was developed and validated to investigate the fluid–structure interactions between fully developed pipe flow and core–shell-structured microcapsule in a microchannel. Different flow rates and microcapsule shell thicknesses were considered. A sixth-order rotational symmetric distribution of von Mises stress over the microcapsule shell can be observed on the microcapsule with a thinner shell configuration, especially at higher flow rate conditions. It is also observed that when being carried along in a fully developed pipe flow, the microcapsule with a thinner shell tends to accumulate stress at a higher rate compared to that with a thicker shell. In general, for the same microcapsule configuration, higher flow velocity would induce a higher stress level over the microcapsule shell. The deformation gradient was used to capture the microcapsule's deformation in the present study. The effect of Young's modulus on the microcapsule shell on the microcapsule deformation was investigated as well. Our findings will shed light on the understanding of the stability of core–shell-structured microcapsule when subjected to flow-induced shear stress in a microfluidic system, enabling a more exquisite control over the breakup dynamics of drug-loaded microcapsule for biomedical applications. 相似文献
6.
Ajit Kumar Singh Seulgi Ji Baghendra Singh Chittaranjan Das Heechae Choi Prashanth W. Menezes Arindam Indra 《Materials Today Chemistry》2022
Herein, we report a Mott-Schottky catalyst by entrapping cobalt nanoparticles inside the N-doped graphene shell (Co@NC). The Co@NC delivered excellent oxygen evolution activity with an overpotential of merely 248 mV at a current density of 10 mA cm–2 with promising long-term stability. The importance of Co encapsulated in NC has further been demonstrated by synthesizing Co nanoparticles without NC shell. The synergy between the hexagonal close-packed (hcp) and face-centered cubic (fcc) Co plays a major role to improve the OER activity, whereas the NC shell optimizes the electronic structure, improves the electron conductivity, and offers a large number of active sites in Co@NC. The density functional theory calculations have revealed that the hcp Co has a dominant role in the surface reaction of electrocatalytic oxygen evolution, whereas the fcc phase induces the built-in electric field at the interfaces with N-doped graphene to accelerate the H+ ion transport. 相似文献
7.
Meccanica - In gear pair actual alternating meshing process, the comprehensive errors of the transmission system and the thermal elastic deformation of the teeth body cause the gears in the meshing... 相似文献
8.
Nonlinear Dynamics - This paper investigates the guaranteed cost positive consensus for linear multi-agent systems (MASs) with multiple time-varying delays and switching topologies. First,... 相似文献
9.
10.
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