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   88篇
  免费   1篇
  国内免费   3篇
化学   39篇
力学   3篇
数学   30篇
物理学   20篇
  2020年   1篇
  2019年   2篇
  2018年   1篇
  2017年   1篇
  2016年   1篇
  2014年   2篇
  2013年   3篇
  2012年   3篇
  2011年   6篇
  2010年   1篇
  2009年   2篇
  2008年   4篇
  2007年   3篇
  2006年   1篇
  2005年   3篇
  2004年   3篇
  2003年   1篇
  2002年   2篇
  2001年   2篇
  2000年   4篇
  1998年   2篇
  1997年   3篇
  1996年   4篇
  1994年   3篇
  1993年   1篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1987年   1篇
  1985年   1篇
  1981年   1篇
  1980年   1篇
  1979年   1篇
  1978年   3篇
  1977年   3篇
  1976年   5篇
  1975年   2篇
  1974年   2篇
  1973年   1篇
  1972年   3篇
  1971年   2篇
  1970年   1篇
  1936年   1篇
  1933年   1篇
排序方式: 共有92条查询结果,搜索用时 281 毫秒
81.
Access to a series of truncated ATP analogs, as potential anti-tuberculosis agents, has been explored via alkylation and acylation of 3-aminophenol, whereas chloroacetylation, using chloroacetyl chloride, and subsequent Arbuzov phosphonation of a series of 3-substituted anilines have afforded a series of phosphonate derivatives as potential antimalarial agents.  相似文献   
82.
Computational methods involving virtual screening could potentially be employed to discover new biomolecular targets for an individual molecule of interest (MOI). However, existing scoring functions may not accurately differentiate proteins to which the MOI binds from a larger set of macromolecules in a protein structural database. An MOI will most likely have varying degrees of predicted binding affinities to many protein targets. However, correctly interpreting a docking score as a hit for the MOI docked to any individual protein can be problematic. In our method, which we term "Virtual Target Screening (VTS)", a set of small drug-like molecules are docked against each structure in the protein library to produce benchmark statistics. This calibration provides a reference for each protein so that hits can be identified for an MOI. VTS can then be used as tool for: drug repositioning (repurposing), specificity and toxicity testing, identifying potential metabolites, probing protein structures for allosteric sites, and testing focused libraries (collection of MOIs with similar chemotypes) for selectivity. To validate our VTS method, twenty kinase inhibitors were docked to a collection of calibrated protein structures. Here, we report our results where VTS predicted protein kinases as hits in preference to other proteins in our database. Concurrently, a graphical interface for VTS was developed.  相似文献   
83.
Corrigendum     
Archive for Rational Mechanics and Analysis -  相似文献   
84.
J/ψ production at 40 GeV/c by π±, K±, p and p incident on hydrogen has been studied and results compared with those obtained on tungsten in the same experiment. On hydrogen, J/ψ cross-section ratios relative to π? have been measured to be (for xF > 0) σ(π?) : σ(π+) : σ(p) : σ(p) = 1 : (0.78 ± 0.09) : (0.83 ± 0.35) : (0.07 ± 0.04). The suppression of the proton induced cross sections shows the importance of calence quark-antiquark fusiin J/ψ production at this energy (i.e. MJ2/ψ/s=0.13).  相似文献   
85.
A novel method capable of differentiating and concentrating small molecules in bulk solution termed “electrophoretic exclusion” is described and experimentally investigated. In this technique, the hydrodynamic flow of the system is countered by the electrophoretic velocity to prevent a species from entering into the channel. The separation can be controlled by changing the flow rate or applied electric field in order to exclude certain species selectively while allowing others to pass through the capillary. Proof of principle studies employed a flow injection regime of the method and examined the exclusion of Methyl Violet dye in the presence of a neutral species. Methyl Violet was concentrated almost 40 times the background concentration in 30 s using 6 kV. Additionally, a threshold voltage necessary for exclusion was determined. The establishment of a threshold voltage enabled the differentiation of two similar cationic species: Methyl Green and Neutral Red.  相似文献   
86.
Intersecting random translates of invariant Cantor sets   总被引:5,自引:0,他引:5  
Summary Given two Cantor setsX andY in [0, 1), invariant under the mapxb x mod 1, the Hausdorff dimension of (X+t)Y is constant almost everywhere. WhenX,Y are defined by admissible digits in baseb, and more generally by sofic systems, we compute this dimension in terms of the largest Lyapunov exponent of a random product of matrices. The results are extended to higher dimensions and multiple intersections.Oblatum 17-VIII-1990Support was provided by an IBM fellowship.Partially supported by a grant from the Landau Centre for Mathematical Analysis  相似文献   
87.
We study continuous time Glauber dynamics for random configurations with local constraints (e.g. proper coloring, Ising and Potts models) on finite graphs with n vertices and of bounded degree. We show that the relaxation time (defined as the reciprocal of the spectral gap |12|) for the dynamics on trees and on planar hyperbolic graphs, is polynomial in n. For these hyperbolic graphs, this yields a general polynomial sampling algorithm for random configurations. We then show that for general graphs, if the relaxation time 2 satisfies 2=O(1), then the correlation coefficient, and the mutual information, between any local function (which depends only on the configuration in a fixed window) and the boundary conditions, decays exponentially in the distance between the window and the boundary. For the Ising model on a regular tree, this condition is sharp.Research supported by Microsoft graduate fellowship.Supported by a visiting position at INRIA and a PostDoc at Microsoft research.Research supported by NSF Grants DMS-0104073, CCR-0121555 and a Miller Professorship at UC Berkeley.Acknowledgement We are grateful to David Aldous, David Levin, Laurent Saloff-Coste and Peter Winkler for useful discussions. We thank Dror Weitz for helpful comments on [19].  相似文献   
88.
A variational principle for domino tilings   总被引:8,自引:0,他引:8  

We formulate and prove a variational principle (in the sense of thermodynamics) for random domino tilings, or equivalently for the dimer model on a square grid. This principle states that a typical tiling of an arbitrary finite region can be described by a function that maximizes an entropy integral. We associate an entropy to every sort of local behavior domino tilings can exhibit, and prove that almost all tilings lie within (for an appropriate metric) of the unique entropy-maximizing solution. This gives a solution to the dimer problem with fully general boundary conditions, thereby resolving an issue first raised by Kasteleyn. Our methods also apply to dimer models on other grids and their associated tiling models, such as tilings of the plane by three orientations of unit lozenges.

  相似文献   

89.
Hausdorff dimensions of sofic affine-invariant sets   总被引:2,自引:0,他引:2  
We determine the Hausdorff and Minkowski dimensions of compact subsets of the 2-torus which are invariant under a linear endomorphism with integer eigenvalues and correspond to shifts of finite type or sofic shifts via some Markov partition. This extends a result of McMullen (1984) and Bedford (1984), who considered full-shifts. This work was completed while the first author was at the Institut Fourier, Grenoble, France, and at MSRI, Berkeley, CA. The research at MSRI was supported in part by NSF grant #DMS 9022140. This work was completed while the second author was at Yale University. Received July 8, 1994  相似文献   
90.
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