全文获取类型
收费全文 | 1282篇 |
免费 | 47篇 |
国内免费 | 7篇 |
专业分类
化学 | 839篇 |
晶体学 | 8篇 |
力学 | 37篇 |
数学 | 226篇 |
物理学 | 226篇 |
出版年
2023年 | 20篇 |
2022年 | 12篇 |
2021年 | 35篇 |
2020年 | 25篇 |
2019年 | 30篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 42篇 |
2015年 | 43篇 |
2014年 | 44篇 |
2013年 | 77篇 |
2012年 | 70篇 |
2011年 | 76篇 |
2010年 | 45篇 |
2009年 | 52篇 |
2008年 | 48篇 |
2007年 | 67篇 |
2006年 | 55篇 |
2005年 | 55篇 |
2004年 | 47篇 |
2003年 | 35篇 |
2002年 | 38篇 |
2001年 | 24篇 |
2000年 | 9篇 |
1999年 | 19篇 |
1998年 | 15篇 |
1997年 | 17篇 |
1996年 | 19篇 |
1995年 | 11篇 |
1994年 | 19篇 |
1993年 | 18篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1989年 | 5篇 |
1988年 | 6篇 |
1987年 | 16篇 |
1986年 | 18篇 |
1985年 | 10篇 |
1984年 | 10篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1980年 | 17篇 |
1978年 | 12篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1975年 | 6篇 |
1974年 | 9篇 |
1972年 | 8篇 |
1971年 | 4篇 |
1933年 | 5篇 |
排序方式: 共有1336条查询结果,搜索用时 15 毫秒
1.
Marcus Carlsson 《Expositiones Mathematicae》2021,39(1):149-157
von Neumann’s inequality in matrix theory refers to the fact that the Frobenius scalar product of two matrices is less than or equal to the scalar product of the respective singular values. Moreover, equality can only happen if the two matrices share a joint set of singular vectors, and this latter part is hard to find in the literature. We extend these facts to the separable Hilbert space setting, and provide a self-contained proof of the “latter part”. 相似文献
2.
Cavitation erosion is caused in solids exposed to strong pressure waves developing in an adjacent fluid field. The knowledge of the transient distribution of stresses in the solid is important to understand the cause of damaging by comparisons with breaking points of the material. The modeling of this problem requires the coupling of the models for the fluid and the solid. For this purpose, we use a strategy based on the solution of coupled Riemann problems that has been originally developed for the coupling of 2 fluids. This concept is exemplified for the coupling of a linear elastic structure with an ideal gas. The coupling procedure relies on the solution of a nonlinear equation. Existence and uniqueness of the solution is proven. The coupling conditions are validated by means of quasi‐1D problems for which an explicit solution can be determined. For a more realistic scenario, a 2D application is considered where in a compressible single fluid, a hot gas bubble at low pressure collapses in a cold gas at high pressure near an adjacent structure. 相似文献
3.
4.
High-precision sub-pixel interpolation in particle image velocimetry image processing 总被引:4,自引:0,他引:4
The task of image interpolation and re-sampling for particle image velocimetry (PIV) is investigated, which is used for window shifting with sub-pixel accuracy and image or window deformation. A new interpolation scheme based on a Gaussian filter is introduced and compared with commonly used and widely accepted interpolation techniques in terms of the achievable root mean square deviation of the displacement estimates. 相似文献
5.
6.
The soft mode dielectric response of three ferroelectric chiral smectic C* substances is studied in the vicinity of the smectic C*-smectic A* phase transition. For some substances the soft mode dielectric strength exhibits a pronounced anomaly in the C* phase just below the phase transition. We show how this anomaly can be systematically correlated with a corresponding anomaly in the experimentally determined ratio of spontaneous polarization over tilt. By comparing the experimental results with the theoretical predictions of an extended Landau model, we demonstrate how the crossover behaviour of the system can be interpreted as being the consequence of the presence of a biquadratic coupling between tilt and polarization in the Landau free-energy of the system. 相似文献
7.
8.
Marcus Carlsson 《Journal of Functional Analysis》2007,247(1):169-201
In this paper we study the boundary behavior of functions in Hilbert spaces of vector-valued analytic functions on the unit disc D. More specifically, we give operator-theoretic conditions on Mz, where Mz denotes the operator of multiplication by the identity function on D, that imply that all functions in the space have non-tangential limits a.e., at least on some subset of the boundary. The main part of the article concerns the extension of a theorem by Aleman, Richter and Sundberg in [A. Aleman, S. Richter, C. Sundberg, Analytic contractions and non-tangential limits, Trans. Amer. Math. Soc. 359 (2007)] to the case of vector-valued functions. 相似文献
9.
Let A(X) be the space defined by Waldhausen whose homotopy groups define the algebraic K-groups of the space X and let
. Here (X) denotes the free loop space of X and Q denotes the functor . For X = Y, the suspension of a connected space Y, we shall prove that the homotopy fibers Ã(X), B(X) of the maps A(X) A (point), B(X) B (point) are equivalent as infinite loop spaces. 相似文献
10.