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   302篇
  免费   3篇
  国内免费   1篇
化学   158篇
晶体学   11篇
力学   2篇
数学   54篇
物理学   81篇
  2022年   4篇
  2020年   8篇
  2019年   9篇
  2018年   2篇
  2017年   8篇
  2016年   7篇
  2015年   5篇
  2014年   10篇
  2013年   19篇
  2012年   21篇
  2011年   20篇
  2010年   5篇
  2009年   11篇
  2008年   13篇
  2007年   8篇
  2006年   16篇
  2005年   13篇
  2004年   7篇
  2003年   14篇
  2002年   12篇
  2001年   6篇
  2000年   2篇
  1999年   3篇
  1996年   4篇
  1995年   2篇
  1994年   2篇
  1990年   4篇
  1989年   2篇
  1988年   5篇
  1987年   2篇
  1986年   4篇
  1985年   2篇
  1984年   6篇
  1983年   4篇
  1982年   8篇
  1980年   3篇
  1976年   3篇
  1974年   2篇
  1972年   3篇
  1971年   2篇
  1966年   2篇
  1961年   1篇
  1960年   1篇
  1959年   3篇
  1957年   1篇
  1947年   3篇
  1946年   1篇
  1941年   1篇
  1939年   1篇
  1938年   1篇
排序方式: 共有306条查询结果,搜索用时 15 毫秒
301.
Automated lead optimization helper application (ALOHA) is a novel fitness scoring approach for small molecule lead optimization. ALOHA employs a series of generalized Bayesian models trained from public and proprietary pharmacokinetic, absorption, distribution, metabolism, and excretion, and toxicology data to determine regions of chemical space that are likely to have excellent drug-like properties. The input to ALOHA is a list of molecules, and the output is a set of individual probabilities as well as an overall probability that each of the molecules will pass a panel of user selected assays. In addition to providing a summary of how and when to apply ALOHA, this paper will discuss the validation of ALOHA’s Bayesian models and probability fusion approach. Most notably, ALOHA is demonstrated to discriminate between members of the same chemical series with strong statistical significance, suggesting that ALOHA can be used effectively to select compound candidates for synthesis and progression at the lead optimization stage of drug discovery.  相似文献   
302.
Ricerche di Matematica - The aim of the present paper, how the people behave towards the offer of two products in two different patches. In this work, an innovation diffusion model with...  相似文献   
303.
We have measured how irradiation by Ar+ and N+ ions modifies electronic conduction in single-wall carbon nanotube (SWNT) networks, finding dramatically different effects for different thicknesses. For very thin transparent networks, ion irradiation increases localization of charge carriers and reduces the variable-range hopping conductivity, especially at low temperatures. However, for thick networks (SWNT paper) showing metallic conductivity, we find a relatively sharp peak in conductivity as a function of irradiation dose. Our investigation of this peak reveals the important role of thermal annealing extending beyond the range of the irradiating ions, and shows the dependence on the morphology of the samples. We propose a simple model that accounts for the temperature-dependent conductivity. PACS 73.63.Fg; 61.80.-x  相似文献   
304.
The electrical resistance of 24 different carbon nanotube (CNT) thin film samples in blowing ambient air and 10 different analyte vapor environments was measured. The effects of the CNT growth method, different chemical treatments, ball milling, sample preparation conditions and Ar+-ion irradiation are compared. Significant differences in the response signal curves as a function of time in the case of the studied sensor/vapor combinations show the important role of the defect structure and attached functional groups in the chemical sensing properties of CNTs.  相似文献   
305.
A novel thiol-ene photopolymerization reaction involving copolymerization of tetrathiol monomer with vinyl silazane is experimentally characterized and is modeled successfully. The overall polymerization rate is found to be controlled by the ratio of the propagation to chain transfer kinetic parameters. The polymerization rate of this mixture, in the presence of added photoinitiator, is approximately first order in ene functionality and is independent of thiol functional group concentration. Initiation rates in this system, when cured utilizing a light centered around 365 nm light, and in the presence of no added photoinitiator, are shown to be proportional to the ene monomer concentration. When the mixture is polymerized utilizing light centered at 254 nm light, and without photoinitiator, the initiation rates are proportional to the thiol monomer concentrations. This novel reaction scheme is further utilized to form ultra rapidly polymerizable polymer derived ceramic structures with high aspect ratios.  相似文献   
306.
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