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   3902篇
  免费   125篇
  国内免费   23篇
化学   2857篇
晶体学   43篇
力学   105篇
数学   473篇
物理学   572篇
  2023年   17篇
  2022年   27篇
  2021年   38篇
  2020年   59篇
  2019年   54篇
  2018年   49篇
  2017年   37篇
  2016年   106篇
  2015年   83篇
  2014年   87篇
  2013年   212篇
  2012年   254篇
  2011年   293篇
  2010年   117篇
  2009年   107篇
  2008年   271篇
  2007年   289篇
  2006年   271篇
  2005年   266篇
  2004年   189篇
  2003年   170篇
  2002年   151篇
  2001年   52篇
  2000年   54篇
  1999年   38篇
  1998年   40篇
  1997年   42篇
  1996年   58篇
  1995年   35篇
  1994年   40篇
  1993年   29篇
  1992年   33篇
  1991年   31篇
  1990年   38篇
  1989年   24篇
  1988年   20篇
  1987年   12篇
  1986年   18篇
  1985年   25篇
  1984年   41篇
  1983年   30篇
  1982年   38篇
  1981年   31篇
  1980年   22篇
  1979年   17篇
  1978年   25篇
  1977年   16篇
  1976年   14篇
  1974年   17篇
  1973年   13篇
排序方式: 共有4050条查询结果,搜索用时 15 毫秒
11.
A semi classical reactive flux algorithm for calculating thermally activated rate constants is presented which is based on a semi-classical transition state theory due to Chapman, Garrett and Miller [J. Chem. Phys. 63 (1975) 2710]. This reactive flux technique, when combined with the semiclassical TST, enables one to describe dynamical recrossings of the transition state on the same footing as tunneling effects. Most importantly, the method is readily applied to nonlinear multidimensional systems over a wide range of temperatures. It will be shown that the method works very well for a variety of existing models.  相似文献   
12.
13.
14.
15.
The European Physical Journal C - We present the most recent high p T results from the CDF experiment using $p\overline{p}$ collisions at $\sqrt{s}=1.96~$ TeV produced at the Tevatron Collider at...  相似文献   
16.
Oritavancin is a semi-synthetic glycopeptide antibiotic which is structurally related to vancomycin. When oritavancin bisphosphate is dried in vacuo with heat, a new compound forms. This new compound is stable only in the solid state and reverts to oritavancin in solution. Highly enriched samples of this compound were obtained by preparative HPLC and the structure of this compound was elucidated by using one and two-dimensional (1H and 13C) NMR spectroscopy in conjunction with computer-assisted molecular modeling. It has been determined that oritavancin adopts a conformation similar to that of vancomycin in solution, while the new compound is the unnatural R-AB-biaryl atropisomer of oritavancin. This is the first observation and isolation of an AB-biaryl atropisomer in an intact member of the vancomycin family of glycopeptide antibiotics.  相似文献   
17.
This paper addresses the problem of designing environmental regulations when firms possess better information about the cost of pollution abatement than regulators. In the regulatory equilibrium derived in the paper, firms are induced to reveal the information they have concerning abatement costs through the judicious use of abatement standard-subsidy combinations. Offering firms a menu of regulatory contracts, each one specifying a required level of pollution abatement as well as a lump sum subsidy to be paid by the regulatory agency to the firm, is shown to be superior to optimal uniform standard-subsidy schemes. By appealing to the revelation principle and employing a second policy instrument (subsidies), albeit a costly one, in conjunction with an abatement standard, the incentive compatible approach to environmental regulation presented in the paper minimizes the economic inefficiency customarily attributable to a lack of initial information regarding pollution abatement costs.  相似文献   
18.
We construct a probability model seemingly unrelated to the considered stochastic process of coagulation and fragmentation. By proving for this model the local limit theorem, we establish the asymptotic formula for the partition function of the equilibrium measure for a wide class of parameter functions of the process. This formula proves the conjecture stated in [5] for the above class of processes. The method used goes back to A. Khintchine.  相似文献   
19.
20.
We establish from local hypotheses some results concerning the final state topology of black holes. We show that the surface of a black hole must have 2-sphere topology and that the topology of space in its vicinity is simple.Dedicated to Ted FrankelThis work has been partially supported by NSF grants DMS-8802877 and DMS-9006678  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