全文获取类型
收费全文 | 1418412篇 |
免费 | 33210篇 |
国内免费 | 9999篇 |
专业分类
化学 | 722205篇 |
晶体学 | 14930篇 |
力学 | 77207篇 |
综合类 | 211篇 |
数学 | 249289篇 |
物理学 | 397779篇 |
出版年
2021年 | 13806篇 |
2020年 | 16743篇 |
2019年 | 16947篇 |
2018年 | 15467篇 |
2017年 | 13731篇 |
2016年 | 29839篇 |
2015年 | 21942篇 |
2014年 | 31686篇 |
2013年 | 76173篇 |
2012年 | 44589篇 |
2011年 | 45159篇 |
2010年 | 40995篇 |
2009年 | 42567篇 |
2008年 | 42336篇 |
2007年 | 38810篇 |
2006年 | 42398篇 |
2005年 | 35545篇 |
2004年 | 35217篇 |
2003年 | 32423篇 |
2002年 | 32871篇 |
2001年 | 33247篇 |
2000年 | 27847篇 |
1999年 | 21786篇 |
1998年 | 19511篇 |
1997年 | 20021篇 |
1996年 | 19812篇 |
1995年 | 19067篇 |
1994年 | 18590篇 |
1993年 | 18067篇 |
1992年 | 18543篇 |
1991年 | 18698篇 |
1990年 | 17912篇 |
1989年 | 17910篇 |
1988年 | 17494篇 |
1987年 | 17403篇 |
1986年 | 16334篇 |
1985年 | 22778篇 |
1984年 | 23848篇 |
1983年 | 19828篇 |
1982年 | 21457篇 |
1981年 | 20646篇 |
1980年 | 19960篇 |
1979年 | 20493篇 |
1978年 | 21634篇 |
1977年 | 21342篇 |
1976年 | 21165篇 |
1975年 | 19869篇 |
1974年 | 19578篇 |
1973年 | 20058篇 |
1972年 | 14528篇 |
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
91.
Dev Raj Alok Kumar Rohit Kumar Singh Abhishek Singh Bhadouria A.S.K. Sinha Deepak Dwivedi 《Current Opinion in Electrochemistry》2022
As the application of electrocatalyst continues to expand, envisaging the hidden mechanisms occurring at various length scale affecting the catalytic efficiency became important. To enhance the stability of electrocatalyst and reduce the cost, it is of paramount importance to reveal the active site's dynamics (using in situ techniques for getting the real-time information) which directly affect the reactions such as oxygen evolution reaction, hydrogen evolution reaction, and so on. Since such reactions are crucial for many engineering and scientific applications, in situ characterization techniques are required, which could capture such reactions happening at a different length and time scale. This article analyzes the recent progress made in the field of electrocatalyst's characterization using in situ neutron techniques. The article also paves the future path and has delineated the future challenges involved in multiscale correlative techniques (e.g., neutron techniques in the combination of synchrotron or microscopic techniques) used for getting the multiscale (atomic to micrometer range) mechanistic information about the electrocatalyst's working and degradation. 相似文献
92.
Journal of Global Optimization - 相似文献
93.
Russian Physics Journal - The paper deals with the low-temperature physical mechanism of inelastic strain of metallic glass, which is the quantum atomic tunneling in a double well potential or... 相似文献
94.
Journal of Russian Laser Research - We construct Gaussian coherent states of a free particle with time-dependent mass, using symplectic tomographic probability distribution and integrals of motion... 相似文献
95.
Chumaevskii A. V. Zykova A. P. Gusarova A. V. Guryanov D. A. Rubtsov V. E. Kolubaev E. A. 《Russian Physics Journal》2022,65(2):303-311
Russian Physics Journal - The results of model experimental studies of structural-phase changes in an AA2024 aluminum alloy after friction with a counter-body of a complex configuration are... 相似文献
96.
Xu Yifan Zhang Hehe Ding Tangjing Tian Ruiqi Sun Dongmei Wang Ming-Sheng Zhou Xiaosi 《中国科学:化学(英文版)》2022,65(9):1807-1816
Science China Chemistry - Due to their enormous potential for large-scale energy storage, rechargeable potassium-ion batteries have been widely researched and developed. However, the drastic volume... 相似文献
97.
98.
Stoyanovskii O. I. Galutskii V. G. Kotov D. I. 《Journal of Applied Mechanics and Technical Physics》2022,63(2):321-328
Journal of Applied Mechanics and Technical Physics - The wear resistance of DI37-VI and EK80-VI steel is studied using a friction testing device. A sample made of high-carbon chromium-vanadium... 相似文献
99.
Given a graph sequence denote by T3(Gn) the number of monochromatic triangles in a uniformly random coloring of the vertices of Gn with colors. In this paper we prove a central limit theorem (CLT) for T3(Gn) with explicit error rates, using a quantitative version of the martingale CLT. We then relate this error term to the well-known fourth-moment phenomenon, which, interestingly, holds only when the number of colors satisfies . We also show that the convergence of the fourth moment is necessary to obtain a Gaussian limit for any , which, together with the above result, implies that the fourth-moment condition characterizes the limiting normal distribution of T3(Gn), whenever . Finally, to illustrate the promise of our approach, we include an alternative proof of the CLT for the number of monochromatic edges, which provides quantitative rates for the results obtained in [7]. 相似文献
100.
Mathematical Notes - A system of new differential-geometric notions as the result of an analysis of the Trudinger–Wang inequalities is proposed. Their naturalness in multivariate analysis and... 相似文献