全文获取类型
收费全文 | 512166篇 |
免费 | 5211篇 |
国内免费 | 1139篇 |
专业分类
化学 | 251368篇 |
晶体学 | 7701篇 |
力学 | 26554篇 |
综合类 | 3篇 |
数学 | 70107篇 |
物理学 | 162783篇 |
出版年
2021年 | 4538篇 |
2020年 | 5153篇 |
2019年 | 5988篇 |
2018年 | 8558篇 |
2017年 | 8518篇 |
2016年 | 11588篇 |
2015年 | 6448篇 |
2014年 | 10669篇 |
2013年 | 22432篇 |
2012年 | 18556篇 |
2011年 | 21779篇 |
2010年 | 16400篇 |
2009年 | 16242篇 |
2008年 | 20221篇 |
2007年 | 20152篇 |
2006年 | 18390篇 |
2005年 | 16417篇 |
2004年 | 15300篇 |
2003年 | 13770篇 |
2002年 | 13727篇 |
2001年 | 13719篇 |
2000年 | 10783篇 |
1999年 | 8135篇 |
1998年 | 7274篇 |
1997年 | 7074篇 |
1996年 | 6743篇 |
1995年 | 5917篇 |
1994年 | 5932篇 |
1993年 | 6059篇 |
1992年 | 6236篇 |
1991年 | 6629篇 |
1990年 | 6387篇 |
1989年 | 6346篇 |
1988年 | 6072篇 |
1987年 | 6029篇 |
1986年 | 5612篇 |
1985年 | 7145篇 |
1984年 | 7570篇 |
1983年 | 6183篇 |
1982年 | 6655篇 |
1981年 | 6281篇 |
1980年 | 5975篇 |
1979年 | 6428篇 |
1978年 | 6617篇 |
1977年 | 6592篇 |
1976年 | 6763篇 |
1975年 | 6214篇 |
1974年 | 6125篇 |
1973年 | 6325篇 |
1972年 | 4858篇 |
排序方式: 共有10000条查询结果,搜索用时 2 毫秒
141.
142.
143.
In this work, the effect of various properties of materials on vacuum breakdown initiated by laser radiation is considered. Estimating calculations are performed which show that the material of the target electrode distinctly affects the minimum energy of laser radiation needed for igniting a vacuum spark. The experimental studies carried out confirm the estimating calculations, and a number of materials are revealed which can be arranged in order of increase in the energy needed for the formation of breakdown in vacuum by the impact of a laser pulse. 相似文献
144.
Colloid Journal - The deposition of aerosol particles in a filter composed of fibers coated with highly porous layers of radially oriented needles and the deposition of needle-coated particles onto... 相似文献
145.
146.
147.
Belakhov V. V. Boikova I. V. Krasnobaeva I. L. Kolodyaznaya V. A. 《Russian Journal of General Chemistry》2021,91(13):2900-2907
Russian Journal of General Chemistry - A method was developed for the synthesis of an organofluorine derivative of β-D-ribofuranoside. Biological tests revealed high insecticidal activity and... 相似文献
148.
Herrasti P. Mazarío E. Recio Francisco J. 《Journal of Solid State Electrochemistry》2021,25(1):231-236
Journal of Solid State Electrochemistry - In this work, the use of neodymium electrodes as a basis for the immobilization of magnetite nanoparticles has been carried out. The sensitivity and... 相似文献
149.
This study compares the physicochemical properties of six electrolytes comprising of three salts: LiFTFSI, NaFTFSI and KFTFSI in two solvent mixtures, the binary (3EC/7EMC) and the ternary (EC/PC/3DMC). The transport properties (conductivity, viscosity) as a function of temperature and concentration were modeled using the extended Jones-Dole-Kaminsky equation, the Arrhenius model, and the Eyring theory of transition state for activated complexes. Results are discussed in terms of ionicity, solvation shell, and cross-interactions between electrolyte components. The application of the six formulated electrolytes in symmetrical activated carbon (AC)//AC supercapacitors (SCs) was characterized by cyclic voltammetry (CV), galvanostatic cycling with potential limitation (GCPL), electrochemical impedance spectroscopy (EIS) and accelerated aging. Results revealed that the geometrical flexibility of the FTFSI anion allows it to access and diffuse easily in AC whereas its counter ions (Li+, Na+ or K+) can remain trapped in porosity. However, this drawback was partially resolved by mixing LiFTFSI and KFTFSI salts in the electrolyte. 相似文献
150.
Journal of Analytical Chemistry - Studies on the separation of the Se and Te trace components from Co, Ni, Cu, Fe, Cr, Mo, and W macrocomponents for their determination by inductively coupled... 相似文献