全文获取类型
收费全文 | 1033篇 |
免费 | 73篇 |
国内免费 | 73篇 |
专业分类
化学 | 3篇 |
力学 | 157篇 |
综合类 | 8篇 |
数学 | 858篇 |
物理学 | 153篇 |
出版年
2024年 | 5篇 |
2023年 | 15篇 |
2022年 | 12篇 |
2021年 | 19篇 |
2020年 | 27篇 |
2019年 | 39篇 |
2018年 | 33篇 |
2017年 | 36篇 |
2016年 | 31篇 |
2015年 | 32篇 |
2014年 | 59篇 |
2013年 | 65篇 |
2012年 | 46篇 |
2011年 | 53篇 |
2010年 | 53篇 |
2009年 | 60篇 |
2008年 | 77篇 |
2007年 | 68篇 |
2006年 | 53篇 |
2005年 | 63篇 |
2004年 | 41篇 |
2003年 | 33篇 |
2002年 | 48篇 |
2001年 | 33篇 |
2000年 | 23篇 |
1999年 | 30篇 |
1998年 | 30篇 |
1997年 | 31篇 |
1996年 | 15篇 |
1995年 | 9篇 |
1994年 | 13篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有1179条查询结果,搜索用时 31 毫秒
11.
《Mathematische Nachrichten》2017,290(17-18):2759-2774
Here we give a new approach to the Paley–Wiener theorem in a Mellin analysis setting which avoids the use of the Riemann surface of the logarithm and analytical branches and is based on new concepts of polar‐analytic function in the Mellin setting and Mellin–Bernstein spaces. A notion of Hardy spaces in the Mellin setting is also given along with applications to exponential sampling formulas of optical physics. 相似文献
12.
13.
Wenchang Chu 《Integral Transforms and Special Functions》2017,28(7):505-518
By reformulating four hypergeometric series formulae, we derive 36 Apéry-like series expressions for the Riemann zeta function, including a couple of identities conjectured by Sun [New series for some special values of L-functions. Nanjing Univ J Math. 2015;32(2): 189–218]. 相似文献
14.
15.
16.
A two-phase model based upon principles of continuum mixture theory is numerically solved to predict the evolution of detonation
in a granulated reactive material. Shock to detonation transition (SDT) is considered whereby combustion is initiated due
to compression of the material by a moving piston. In particular, this study demonstrates the existence of a SDT event which
gives rise to a steady two-phase Chapman-Jouguet (CJ) detonation structure consisting of a single lead shock in the gas and
an unshocked solid; this structure has previously been independently predicted by a steady-state theory. The unsteady model
equations, which constitute a non-strictly hyperbolic system, are numerically solved using a modern high-resolution method.
The numerical method is based on Godunov's method, and utilizes an approximate solution for the two-phase Riemann problem.
Comparisons are made between numerical predictions and known theoretical results for 1) an inert two-phase shock tube problem,
2) an inert compaction wave structure, and 3) a reactive two-phase detonation structure; in all cases, good agreement exists.
Received 4 August 1995 / Accepted 17 February 1996 相似文献
17.
双周期圆截面纤维复合材料平面问题的解析法 总被引:4,自引:0,他引:4
结合双准周期Riemann边值问题理论与Eshelby等效夹杂原理,为双周期圆截面纤维复合材
料平面问题发展了一个实用有效的解析方法,获得了问题的全场级数解并与有限元结果进行
了比较. 该方法为非均匀材料的力学性质分析和复合材料等新材料的微结构设计提供了
一个有效的计算工具,也可用来评估有限元等数值与近似方法的精度. 相似文献
18.
We study 2×2 systems of hyperbolic conservation laws near an umbilic point. These systems have Undercompressive shock wave solutions, i.e., solutions whose viscous profiles are represented by saddle connections in an associated family of planar vector fields. Previous studies near umbilic points have assumed that the flux function is a quadratic polynomial, in which case saddle connections lie on invariant lines. We drop this assumption and study saddle connections using Golubitsky-Schaeffer equilibrium bifurcation theory and the Melnikov integral, which detects the breaking of heteroclinic orbits. The resulting information is used to construct solutions of Riemann problems. 相似文献
19.
采用流体体积分数的混合型多流体数值模型,将piecewise parabolic method (PPM)方法应用于可压缩多流体流动的数值模拟,拓展了以前提出的模型和数值方法,使它能够处理一般的Mie-Grneisen状态方程。采用双波近似和两层迭代算法求解一般状态方程的Riemann问题;并根据多流体接触界面无振荡原则设计高精度计算格式,对典型的纯界面平移问题可以从理论上证明本算法在接触间断附近压力和速度没有振荡,而且数值模拟结果表明界面数值耗散也被控制在2~3个网格之内。模拟了多种复杂的可压缩多流体流动,算例结果表明本文方法可以有效地处理接触间断、激波等物理问题,且具有耗散小精度高的特点。 相似文献
20.
The HLLEM scheme is a popular contact and shear preserving approximate Riemann solver that is known to be plagued by various forms of numerical shock instability. In this paper, we clarify that the shock instability exhibited by this scheme is primarily triggered by the spurious activation of the antidiffusive terms present in the first and third Riemann flux components on the transverse interfaces adjoining the shock front due to numerical perturbations. These erroneously activated terms are shown to counteract the favorable damping mechanism provided by its inherent HLL-type diffusive terms, causing an unphysical variation of the conserved quantity ρu both along and across the numerical shock. To prevent this, two distinct strategies are proposed termed as S elective W ave M odification and A nti D iffusion C ontrol. The former focuses on enhancing the quantity of the favorable HLL-type dissipation available on these critical flux components by carefully increasing the magnitudes of certain nonlinear wave speed estimates, while the latter focuses on directly controlling the magnitude of these critical antidiffusive terms. A linear perturbation analysis is performed to gauge the effectiveness of these cures and to estimate a von Neumann–type stability bounds on the CFL number associated with their use. Results from a variety of classic shock instability test cases show that the proposed strategies are able to provide excellent shock stable solutions even on grids that are highly elongated across the shock front without compromising the accuracy on inviscid contact or shear dominated viscous flows. 相似文献