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   325111篇
  免费   7627篇
  国内免费   3274篇
化学   178272篇
晶体学   3558篇
力学   14316篇
综合类   174篇
数学   38033篇
物理学   101659篇
  2021年   2122篇
  2020年   2780篇
  2019年   2719篇
  2018年   2610篇
  2017年   2423篇
  2016年   4771篇
  2015年   4182篇
  2014年   5509篇
  2013年   15407篇
  2012年   12400篇
  2011年   15217篇
  2010年   9467篇
  2009年   9382篇
  2008年   13476篇
  2007年   13493篇
  2006年   13130篇
  2005年   11916篇
  2004年   10652篇
  2003年   9227篇
  2002年   8438篇
  2001年   10061篇
  2000年   7504篇
  1999年   5890篇
  1998年   4608篇
  1997年   4584篇
  1996年   4582篇
  1995年   4513篇
  1994年   4260篇
  1993年   4035篇
  1992年   4515篇
  1991年   4370篇
  1990年   4035篇
  1989年   3852篇
  1988年   4100篇
  1987年   3735篇
  1986年   3649篇
  1985年   5301篇
  1984年   5347篇
  1983年   4329篇
  1982年   4704篇
  1981年   4746篇
  1980年   4476篇
  1979年   4617篇
  1978年   4614篇
  1977年   4593篇
  1976年   4561篇
  1975年   4456篇
  1974年   4318篇
  1973年   4488篇
  1972年   2532篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Pomogaev  V. A.  Lee  H. J.  Goh  E.  Tchaikovskaya  O. N.  Kononov  A. I.  Avramov  P. V. 《Russian Physics Journal》2022,64(11):2076-2081
Russian Physics Journal - Theoretical calculations of excited states in the complexes of gold and silver three-atom nanoclusters with carbon quantum nanodots are performed using the M062X...  相似文献   
2.
Structural Chemistry - In the present work, the energy contribution of the sulfur atom in a heterocycle and in a disulfide bond in solid and gas phases was calculated. To achieve this goal,...  相似文献   
3.
The European Physical Journal A - The goal of the present paper is twofold. First, a novel expansion many-body method applicable to superfluid open-shell nuclei, the so-called Bogoliubov in-medium...  相似文献   
4.
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   
5.
Transport in Porous Media - Membrane filtration of feed containing multiple species of particles is a common process in the industrial setting. In this work, we propose a model for filtration of a...  相似文献   
6.
Carnicer  J. M.  Khiar  Y.  Peña  J. M. 《Numerical Algorithms》2022,90(4):1691-1713
Numerical Algorithms - An inverse central ordering of the nodes is proposed for the Newton interpolation formula. This ordering may improve the stability for certain distributions of nodes. For...  相似文献   
7.
Journal of Solid State Electrochemistry - Sodium-ion batteries have emerged as an exciting alternative to commercially dominant lithium-ion batteries for electric vehicles and other applications....  相似文献   
8.
Atopic dermatitis is characterized by leukocyte migration into the skin dermis and typically driven by excessive chemokine production at the site of inflammation. Conventional topical formulations such as gels, creams, and ointments are insufficient for this treatment because of low penetration of drug molecules into the targeted skin tissues. Herein, using a simple, green, sustainable strategy, we have developed novel primary zein nanoparticles embedded in curcumin (Cur) and coated with silk sericin (ZHSCs) for the topical delivery of Cur to penetrate into the dermis and exercise anti-dermatitis effects on the lesion with minimal side-effects. Transdermal delivery experiments and porcine skin fluorescence imaging indicated that ZHSCs facilitate the penetration of Cur across the epidermis layer of skin to reach deep-seated sites. Notably, ZHSCs = 1:0.25 (zein-to-silk sericin mass ratios of 1:0.25) markedly elevated the skin permeability and cumulative turnover of Cur transferred, which were provided a greater than a 3.8-fold increase relative to free Cur. The special nanoparticles of ZHS = 1:0.25 possessed the deepest localization depth and experience a transition of the particle structure and core-shell separation after penetrating into the dermis of skin. In a cell model of dermatitis induced by tumor necrosis factor α/interferon γ co-stimulation, compared with free Cur, Cur-loaded ZHS nanoparticles down-regulated the generation of inflammatory cytokines and chemokines in keratinocytes through suppression of the nuclear translocation of NF-κBp65 and hence exerted an anti-dermatitis effect. This strategy may provide new avenues and direction for the demanding issues of valid topical delivery systems.  相似文献   
9.
Tang  Yixuan  Tian  Qiang  Hu  Haiyan 《Nonlinear dynamics》2022,109(4):2319-2354
Nonlinear Dynamics - To describe the particular mechanical behaviors of beams with both uniform and non-uniform cross sections, such as the bidirectional bending, torsion-bending coupling, the...  相似文献   
10.
Saikia  D.  Parnami  Sugam  Borah  J. P. 《JETP Letters》2022,116(7):444-448
JETP Letters - The magnetic properties of Co-doped CdS has been investigated by ab initio calculations using the GGA + U approximation. The study reveals the ferromagnetic ordering of Co-doped CdS...  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