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   734篇
  免费   21篇
  国内免费   1篇
化学   573篇
晶体学   3篇
力学   10篇
数学   93篇
物理学   77篇
  2023年   4篇
  2022年   6篇
  2021年   11篇
  2020年   4篇
  2019年   12篇
  2018年   11篇
  2017年   9篇
  2016年   18篇
  2015年   19篇
  2014年   15篇
  2013年   40篇
  2012年   31篇
  2011年   53篇
  2010年   26篇
  2009年   24篇
  2008年   38篇
  2007年   29篇
  2006年   28篇
  2005年   26篇
  2004年   23篇
  2003年   19篇
  2002年   19篇
  2001年   22篇
  2000年   12篇
  1999年   13篇
  1998年   14篇
  1997年   8篇
  1996年   14篇
  1995年   8篇
  1994年   4篇
  1992年   10篇
  1991年   7篇
  1990年   7篇
  1989年   8篇
  1988年   8篇
  1987年   5篇
  1986年   7篇
  1985年   12篇
  1984年   9篇
  1983年   6篇
  1982年   5篇
  1974年   4篇
  1970年   6篇
  1968年   5篇
  1912年   4篇
  1907年   4篇
  1876年   4篇
  1871年   3篇
  1867年   3篇
  1862年   3篇
排序方式: 共有756条查询结果,搜索用时 15 毫秒
701.
    
Ohne ZusammenfassungMitteilung der Versuchsstation Bonn.  相似文献   
702.
    
Ohne Zusammenfassung(3. Abhandlung.)  相似文献   
703.
    
Ohne Zusammenfassung  相似文献   
704.
705.
Machura, Shelah and Tsaban showed in [M. Machura, S. Shelah, B. Tsaban, Squares of Menger-bounded groups, Trans. Amer. Math. Soc., in press, http://arxiv.org/pdf/math.GN/0611353, 2007] that under the condition, that a relative d(P) of the dominating number is at least d, there are subgroups of the Baer-Specker group whose kth power is Menger-bounded and whose (k+1)st power is not. We show that the sufficient condition implies r?d and indeed can be replaced by r?d. This result includes an affirmative answer to a question by Tsaban on a possibly weaker still sufficient condition. We show that it is consistent relative to ZFC that g?r<d and there are subgroups of the Baer-Specker group whose kth power is Menger-bounded and whose (k+1)st power is not.  相似文献   
706.
707.
Magnetic nanoparticles have been investigated for biomedical applications for more than 30 years. The development of biocompatible nanosized drug delivery systems for specific targeting of therapeutics is imminent in medical research, especially for treating cancer and vascular diseases. We used drug-labeled magnetic iron oxide nanoparticles, which were attracted to an experimental tumor in rabbits with an external magnetic field (magnetic drug targeting, MDT). Aim of this study was to detect and quantify the biodistribution of the magnetic nanoparticles by magnetorelaxometry. The study shows higher amount of nanoparticles in the tumor after intraarterial application and MDT compared to intravenous administration.  相似文献   
708.
This paper presents an evaluation of the results obtained from an initial study carried out at the IBMB, Technical University of Braunschweig, on the influence of temperature on adhesively bonded plate-concrete joint systems. The results of a theoretical model are also presented. The type of specimen used in this study is a three-point bending beam. The concrete specimens were prismatic in form, 100 × 100 × 700 mm without an internal steel reinforcement, strengthened at the intradoss with two types of UD CFRP lamina 20 mm wide and 590 mm long of thickness 1.4 mm for the E = 300 GPa type and 1.24 mm for the E = 175 GPa type. The plate-bonded specimens were designed to produce bending failure under a load, by not bonding the lamina and the concrete around the midspan of the specimens. The specimens were tested to failure at –100°, –30°, and +40°C after an approximately homogeneous temperature distribution within the concrete specimen has been reached. For comparison only, specimens of the same type were tested to failure at room temperature. The results obtained showed varying behavior of the bonded plate-concrete joint depending on variations in temperature. Furthermore, they showed different failure mechanisms. Greater reductions in the ultimate bond force were recorded for the test specimens strengthened with lamina having a high elastic modulus. A reasonable correlation was found between the experimental and theoretical results.  相似文献   
709.
710.
Andreas Neubauer  Hanna K. Pikkarainen 《PAMM》2007,7(1):1080103-1080104
Recently, the metrics of Ky Fan and Prokhorov were introduced as a tool for studying convergence of regularization methods for stochastic ill-posed problems. In this work, we examine the Bayesian approach to linear inverse problems in this new framework. We consider the finite-dimensional case where the measurements are disturbed by an additive normal noise and the prior distribution is normal. A convergence rate result for the posterior distribution is obtained when the covariance matrices are proportional to the identity matrix. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)  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