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   190327篇
  免费   2176篇
  国内免费   609篇
化学   105032篇
晶体学   2051篇
力学   7762篇
综合类   4篇
数学   18128篇
物理学   60135篇
  2016年   2279篇
  2015年   1687篇
  2014年   2407篇
  2013年   7853篇
  2012年   5272篇
  2011年   6633篇
  2010年   4440篇
  2009年   4371篇
  2008年   6017篇
  2007年   6186篇
  2006年   5923篇
  2005年   5367篇
  2004年   4890篇
  2003年   4339篇
  2002年   3904篇
  2001年   5561篇
  2000年   4100篇
  1999年   3210篇
  1998年   2427篇
  1997年   2554篇
  1996年   2477篇
  1995年   2414篇
  1994年   2302篇
  1993年   2173篇
  1992年   2686篇
  1991年   2544篇
  1990年   2507篇
  1989年   2527篇
  1988年   2472篇
  1987年   2479篇
  1986年   2296篇
  1985年   3199篇
  1984年   3225篇
  1983年   2615篇
  1982年   2826篇
  1981年   2787篇
  1980年   2667篇
  1979年   2834篇
  1978年   3092篇
  1977年   2904篇
  1976年   2855篇
  1975年   2702篇
  1974年   2658篇
  1973年   2682篇
  1972年   1726篇
  1969年   1453篇
  1968年   1932篇
  1967年   2128篇
  1966年   1921篇
  1965年   1498篇
排序方式: 共有10000条查询结果,搜索用时 15 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.
Annals of Operations Research - In recent years, operations research in agriculture has improved the harvested yield, reduced the cost and time required for field operations, and maintained...  相似文献   
3.
Statistical Inference for Stochastic Processes - The class of autoregressive (AR) processes is extensively used to model temporal dependence in observed time series. Such models are easily...  相似文献   
4.
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   
5.
Applied Mathematics and Mechanics - Mechanical models of residually stressed fibre-reinforced solids, which do not resist bending, have been developed in the literature. However, in some residually...  相似文献   
6.
Journal of Analytical Chemistry - The review considers the historical aspects of the formation and development of bioelectrochemistry and some issues of the analytical application of...  相似文献   
7.
Sun  J.  Yuan  H. 《Experimental Mechanics》2021,61(3):565-580
Experimental Mechanics - Temperature gradients significantly affect the material fatigue process. A reliable and robust test procedure is needed for quantifying the effects of temperature gradients...  相似文献   
8.
JETP Letters - The results of the first run (December 2020) for the commissioning of the new superconducting synchrotron Booster at the Joint Institute for Nuclear Research are presented. Vacuum...  相似文献   
9.
Zhang  F.  Yi  S. H.  Niu  H. B.  Lu  X. G.  Wang  X. X. 《Fluid Dynamics》2021,56(3):383-392
Fluid Dynamics - To predict the boundary layer transition on swept wings, experimental and numerical researches were conducted to obtained the accurate boundary layer transition front and to...  相似文献   
10.
Journal of Theoretical Probability - This work presents an infinite-dimensional generalization of the correspondence between the Kullback–Leibler and Rényi divergences between Gaussian...  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