全文获取类型
收费全文 | 35505篇 |
免费 | 6331篇 |
国内免费 | 4193篇 |
专业分类
化学 | 24727篇 |
晶体学 | 383篇 |
力学 | 2448篇 |
综合类 | 307篇 |
数学 | 4681篇 |
物理学 | 13483篇 |
出版年
2024年 | 37篇 |
2023年 | 706篇 |
2022年 | 823篇 |
2021年 | 1094篇 |
2020年 | 1432篇 |
2019年 | 1398篇 |
2018年 | 1249篇 |
2017年 | 1171篇 |
2016年 | 1765篇 |
2015年 | 1755篇 |
2014年 | 2029篇 |
2013年 | 2683篇 |
2012年 | 3202篇 |
2011年 | 3281篇 |
2010年 | 2324篇 |
2009年 | 2245篇 |
2008年 | 2413篇 |
2007年 | 2052篇 |
2006年 | 1866篇 |
2005年 | 1616篇 |
2004年 | 1284篇 |
2003年 | 1050篇 |
2002年 | 1055篇 |
2001年 | 896篇 |
2000年 | 736篇 |
1999年 | 800篇 |
1998年 | 675篇 |
1997年 | 624篇 |
1996年 | 571篇 |
1995年 | 558篇 |
1994年 | 464篇 |
1993年 | 406篇 |
1992年 | 332篇 |
1991年 | 306篇 |
1990年 | 268篇 |
1989年 | 211篇 |
1988年 | 152篇 |
1987年 | 103篇 |
1986年 | 85篇 |
1985年 | 79篇 |
1984年 | 60篇 |
1983年 | 45篇 |
1982年 | 46篇 |
1981年 | 28篇 |
1980年 | 11篇 |
1979年 | 8篇 |
1978年 | 4篇 |
1974年 | 5篇 |
1957年 | 8篇 |
1936年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
We experimentally analyze the heat capacity and thermal expansion of reference solids in a wide temperature range from several Kelvin to melting temperature,and establish a universal double-linear relation between the experimental heat capacity Cp and thermal expansion β,which is different from the previous models.The universal behavior between heat capacity and thermal expansion is important to predict the thermodynamic parameters at constant pressure,and is helpful for understanding the nature of thermal properties in solids. 相似文献
2.
In this paper, we study vanishing and splitting results on a complete smooth metric measure space \((M^n,g,\mathrm {e}^{-f}\mathrm {d}v)\) with various negative m-Bakry-Émery Ricci curvature lower bounds in terms of the first eigenvalue \(\lambda _1(\Delta _f)\) of the weighted Laplacian \(\Delta _f\), i.e., \(\mathrm {Ric}_{m,n}\ge -a\lambda _1(\Delta _f)-b\) for \(0<a\le \dfrac{m}{m-1}, b\ge 0\). In particular, we consider three main cases for different a and b with or without conditions on \(\lambda _1(\Delta _f)\). These results are extensions of Dung and Vieira, and weighted generalizations of Li-Wang, Dung-Sung, and Vieira.
相似文献3.
Designs, Codes and Cryptography - Large sets of combinatorial designs has always been a fascinating topic in design theory. These designs form a partition of the whole space into combinatorial... 相似文献
4.
Nonlinear Dynamics - This article considers a reaction–diffusion predator–prey model with schooling behavior both in predator and prey species and subject to the homogeneous Neumann... 相似文献
5.
Zheng Xinyan Hu Po Yao Ruxian cheng Jinhe Chang Yiheng Wu Haitao Mei Hongying Sun Shuxiang Chen Qingtai liu Fang Chen Shujing Wen Hua 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(5):2217-2226
Journal of Radioanalytical and Nuclear Chemistry - Enhancement of U(VI) biomineralization by Saccharomyces cerevisiae through addition of inorganic phosphorus was studied in this work. The addition... 相似文献
6.
Hu Duo-Duo Gao Qian Dai Jing-Cheng Cui Ru Li Yuan-Bo Li Yuan-Ming Zhou Xiao-Guo Bian Kang-Jie Wu Bing-Bing Zhang Kai-Fan Wang Xi-Sheng Li Yan 《中国科学:化学(英文版)》2022,65(4):753-761
Science China Chemistry - A light-induced, nickel-catalyzed three-component arylsulfonation of 1,3-enynes in the absence of photocatalyst is reported. This methodology exhibited mild conditions,... 相似文献
7.
Qi-Feng Zhou 《高分子科学》2022,40(1):1-1
The year 2022 marks the 40th anniversary of the Chinese Journal of Polymer Science(CJPS)—a true milestone to be celebrated!In the early stage of the reform and opening,there was an increasing demand for international academic communications.To facilitate these communications. 相似文献
8.
Hanghang Zhou Dr. Ying Luo Dr. Jun Xu Dr. Lidan Deng Prof. Dr. Zheng Wang Prof. Dr. Hong He 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(68):e202202044
Cubic-like CaTaO2N photocatalysts with high crystallinity and uniform particle size were successfully prepared by the flux-assisted nitridation method. The growth of CaTaO2N single crystals under different synthesis conditions was systematically investigated to understand the effects of the crystallinity and optical property on photocatalytic performance of CO2 reduction. Moreover, the modification of CaTaO2N single crystals with core-shell Ni−Ag bicomponent cocatalyst by two-step decoration process gave a 2.4 times higher amount of CO evolution than the deposition of sole Ag cocatalyst, because of the synergistic effects of bicomponent cocatalyst on the interfacial electron transfer and surface catalytic process. This study provides a valuable way to construct high-crystalline photocatalysts with effective bicomponent cocatalyst for visible-light-driven CO2 reduction with H2O. 相似文献
9.
Nonlinear Dynamics - In this paper, the high-order coupled variable coefficient nonlinear Schrödinger equations is studied. The double-hump soliton solutions for the equations are obtained... 相似文献
10.
Yao Wen Chen Yangfan Li Jiangling Yang Jian Ren Shan Liu Weizao Liu Qingcai 《Research on Chemical Intermediates》2022,48(5):1813-1829
Research on Chemical Intermediates - Industrial wastewater is becoming a universal environmental problem, wherein toxic organic compounds are important sources of pollution. For the degradation... 相似文献