全文获取类型
收费全文 | 994篇 |
免费 | 47篇 |
国内免费 | 2篇 |
专业分类
化学 | 611篇 |
晶体学 | 5篇 |
力学 | 29篇 |
数学 | 123篇 |
物理学 | 275篇 |
出版年
2024年 | 3篇 |
2023年 | 17篇 |
2022年 | 26篇 |
2021年 | 30篇 |
2020年 | 34篇 |
2019年 | 36篇 |
2018年 | 32篇 |
2017年 | 28篇 |
2016年 | 58篇 |
2015年 | 43篇 |
2014年 | 42篇 |
2013年 | 66篇 |
2012年 | 87篇 |
2011年 | 82篇 |
2010年 | 59篇 |
2009年 | 31篇 |
2008年 | 45篇 |
2007年 | 40篇 |
2006年 | 39篇 |
2005年 | 31篇 |
2004年 | 20篇 |
2003年 | 17篇 |
2002年 | 20篇 |
2001年 | 12篇 |
2000年 | 4篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 10篇 |
1996年 | 13篇 |
1995年 | 4篇 |
1994年 | 11篇 |
1993年 | 17篇 |
1992年 | 4篇 |
1990年 | 11篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 6篇 |
1986年 | 6篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1959年 | 2篇 |
排序方式: 共有1043条查询结果,搜索用时 15 毫秒
91.
Subhashis Ghosal Jayanta K. Ghosh Tapas Samanta 《Annals of the Institute of Statistical Mathematics》1999,51(3):479-497
We consider a family of models that arise in connection with sharp change in hazard rate corresponding to high initial hazard rate dropping to a more stable or slowly changing rate at an unknown change-point . Although the Bayes estimates are well behaved and are asymptotically efficient, it is difficult to compute them as the posterior distributions are generally very complicated. We obtain a simple first order asymptotic approximation to the posterior distribution of . The accuracy of the approximation is judged through simulation. The approximation performs quite well. Our method is also applied to analyze a real data set. 相似文献
92.
An analysis is carried out to study the steady two-dimensional stagnation-point flow and heat transfer of an incompressible viscous fluid over a porous shrinking sheet in the presence of thermal radiation. A set of similarity transformations reduce the boundary layer equations to a set of non-linear ordinary differential equations which are solved numerically using fourth order Runge-Kutta method with shooting technique. The analysis of the result obtained shows that as the porosity parameter β increases, the range of region of existence of similarity solution increases. It is also observed that multiple solutions exist for a certain range of the ratio of the shrinking velocity to the free stream velocity (i.e., α) which again depends on β. We then discuss the stability of the unsteady solutions about each steady solution, showing that one steady state solution corresponds to a stable solution whereas the other corresponds to an unstable solution. The stable solution corresponds to the physically relevant solution. Further we obtain numerical results for each solution, which enable us to discuss the features of the respective solutions. 相似文献
93.
A new method for exact solutions of variant types of time‐fractional Korteweg‐de Vries equations in shallow water waves 下载免费PDF全文
The current article devoted on the new method for finding the exact solutions of some time‐fractional Korteweg–de Vries (KdV) type equations appearing in shallow water waves. We employ the new method here for time‐fractional equations viz. time‐fractional KdV‐Burgers and KdV‐mKdV equations for finding the exact solutions. We use here the fractional complex transform accompanied by properties of local fractional calculus for reduction of fractional partial differential equations to ordinary differential equations. The obtained results are demonstrated by graphs for the new solutions. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
94.
Jiaolong Chen Peijin Li Swadesh Kumar Sahoo Xiantao Wang 《Israel Journal of Mathematics》2017,220(1):453-478
We first investigate the Lipschitz continuity of (K,K’)-quasiregular C 2 mappings between two Jordan domains with smooth boundaries, satisfying certain partial differential inequalities concerning Laplacian. Then two applications of the obtained result are given: As a direct consequence, we get the Lipschitz continuity of ρ-harmonic (K,K’)-quasiregular mappings, and as the other application, we study the Lipschitz continuity of (K,K’)- quasiconformal self-mappings of the unit disk, which are the solutions of the Poisson equation Δw = g. These results generalize and extend several recently obtained results by Kalaj, Mateljevi? and Pavlovi?. 相似文献
95.
Ratikanta Behera Ashish Kumar Nandi Jajati Keshari Sahoo 《Numerical Linear Algebra with Applications》2020,27(5)
The notion of the Drazin inverse of an even‐order tensors with the Einstein product was introduced, very recently [J. Ji and Y. Wei. Comput. Math. Appl., 75(9), (2018), pp. 3402‐3413]. In this article, we further elaborate this theory by establishing a few characterizations of the Drazin inverse and ‐weighted Drazin inverse of tensors. In addition to these, we compute the Drazin inverse of tensors using different types of generalized inverses and full rank decomposition of tensors. We also address the solution of multilinear systems by using the Drazin inverse and iterative (higher order Gauss‐Seidel) method of tensors. Besides these, the convergence analysis of the iterative technique is also investigated within the framework of the Einstein product. 相似文献
96.
97.
98.
We study complete convergence of martingale arrays under rather weak conditions. Our results considerably strengthen many of the results available in the literature. As a tool, we establish a martingale analogue of an inequality of Hoffman-Jørgensen which was earlier known only for independent random variables. 相似文献
99.
The 3-dimensional zero-pressure gas dynamics system appears in the modeling for the large scale structure formation in the universe. The aim of this paper is to construct spherically symmetric solutions to the system. The radial component of the velocity and density satisfy a simpler one dimensional problem. First we construct explicit solutions of this one dimensional case with initial and boundary conditions. Then we get special radial solutions with different behaviours at the origin. 相似文献
100.
For distinct points x1,x2,…,xn in ℛ (the reals), letϕ[x1, x2,…,xn] denote the divided difference ofϕ. In this paper, we determine the general solutionϕ,g: ℛ → ℛ of the functional equationϕ[x1,x2,…,xn] =g(x1,+ x2 + … + xn) for distinct x1,x2,…, xn in ℛ without any regularity assumptions on the unknown functions. 相似文献