首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   662693篇
  免费   6467篇
  国内免费   1664篇
化学   343667篇
晶体学   10052篇
力学   31746篇
综合类   26篇
数学   83191篇
物理学   202142篇
  2021年   5828篇
  2020年   6481篇
  2019年   7306篇
  2018年   9550篇
  2017年   9744篇
  2016年   13631篇
  2015年   7590篇
  2014年   12650篇
  2013年   29758篇
  2012年   22562篇
  2011年   26961篇
  2010年   20002篇
  2009年   19872篇
  2008年   25246篇
  2007年   24977篇
  2006年   22873篇
  2005年   20523篇
  2004年   18976篇
  2003年   17212篇
  2002年   16946篇
  2001年   18599篇
  2000年   14388篇
  1999年   11135篇
  1998年   9446篇
  1997年   9300篇
  1996年   8711篇
  1995年   7967篇
  1994年   7876篇
  1993年   7509篇
  1992年   8409篇
  1991年   8734篇
  1990年   8437篇
  1989年   8342篇
  1988年   8210篇
  1987年   8057篇
  1986年   7687篇
  1985年   9800篇
  1984年   10137篇
  1983年   8367篇
  1982年   8709篇
  1981年   8298篇
  1980年   7840篇
  1979年   8566篇
  1978年   8817篇
  1977年   8784篇
  1976年   8591篇
  1975年   8144篇
  1974年   7955篇
  1973年   8117篇
  1972年   5849篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
191.
Journal of Thermal Analysis and Calorimetry - Over the last few decades, tremendous consideration is drawn towards corrugation surfaces because of their advantages over the improvement in thermal...  相似文献   
192.
Journal of Thermal Analysis and Calorimetry - In this paper, the variation of thermophysical properties such as the thermal conductivity, thermal energy storage capacity, viscosity, and phase...  相似文献   
193.
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   
194.
ABSTRACT

The authors present the results of an investigation in Fe–Ni-Cr austenitic alloys of the low-temperature deformation-induced segregations of nickel that form in the micro regions being (i) located close to grain- and subgrain boundaries and (ii) characteristic of the concentration and magnetic inhomogeneities indicated by the appearance of a dark diffraction contrast at the electron diffraction patterns taken from these regions typical (at the same time) of an enhanced value of Curie temperature. The observed effects were connected with the micro distortions caused by the local change of lattice parameter because of an increase in nickel concentration, as well as in the result of a magnetostriction dilatation. Using methods of the X-ray energy dispersive spectroscopy (XEDS) and atomic-probe body-section radiography (tomography – APT) has made it possible to determine the borders of those regions of austenite that were characteristic of an enhanced concentration of nickel in the fields of the localisation of a deformation-induced segregation of nickel in the vicinity of grain (subgrain) boundaries of austenitic alloys of the types Fe–13Cr–30Ni and Fe–37Ni–3Ti.  相似文献   
195.
High-energy assisted extraction techniques, like ultrasound assisted extraction (UAE) and microwave assisted extraction (MAE), are widely applied over the last years for the recovery of bioactive compounds such as carotenoids, antioxidants and phenols from foods, animals and herbal natural sources. Especially for the case of xanthophylls, the main carotenoid group of crustaceans, they can be extracted in a rapid and quantitative way with the use of UAE and MAE.  相似文献   
196.
Molecular dynamics simulation was performed to study the formation of cluster structure, interfaces, and surfaces with different curvature radii in a perfect nanocrystal passed through by a nonlinear wave. It is shown that this process is a type of nanostructure self-organization in response to an external energy flux with subsequent development of a strong rotational field.  相似文献   
197.
198.
199.
Shinkorenko  A. S. 《JETP Letters》2022,116(10):759-759
JETP Letters - An Erratum to this paper has been published: https://doi.org/10.1134/S0021364022400028  相似文献   
200.
Molecular Diversity - Hypertension is a medical condition that affects millions of people worldwide. Despite the high efficacy of the current antihypertensive drugs, they are associated with...  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号