全文获取类型
收费全文 | 28712篇 |
免费 | 3422篇 |
国内免费 | 1883篇 |
专业分类
化学 | 1677篇 |
晶体学 | 16篇 |
力学 | 3228篇 |
综合类 | 337篇 |
数学 | 20657篇 |
物理学 | 8102篇 |
出版年
2024年 | 59篇 |
2023年 | 293篇 |
2022年 | 298篇 |
2021年 | 437篇 |
2020年 | 853篇 |
2019年 | 843篇 |
2018年 | 797篇 |
2017年 | 746篇 |
2016年 | 829篇 |
2015年 | 685篇 |
2014年 | 1274篇 |
2013年 | 2533篇 |
2012年 | 1338篇 |
2011年 | 1700篇 |
2010年 | 1657篇 |
2009年 | 1817篇 |
2008年 | 1927篇 |
2007年 | 1877篇 |
2006年 | 1606篇 |
2005年 | 1624篇 |
2004年 | 1354篇 |
2003年 | 1325篇 |
2002年 | 1163篇 |
2001年 | 878篇 |
2000年 | 851篇 |
1999年 | 800篇 |
1998年 | 741篇 |
1997年 | 626篇 |
1996年 | 470篇 |
1995年 | 381篇 |
1994年 | 321篇 |
1993年 | 208篇 |
1992年 | 198篇 |
1991年 | 215篇 |
1990年 | 183篇 |
1989年 | 100篇 |
1988年 | 103篇 |
1987年 | 101篇 |
1986年 | 102篇 |
1985年 | 99篇 |
1984年 | 95篇 |
1983年 | 52篇 |
1982年 | 93篇 |
1981年 | 81篇 |
1980年 | 58篇 |
1979年 | 60篇 |
1978年 | 38篇 |
1977年 | 32篇 |
1976年 | 23篇 |
1973年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
171.
172.
Ling-yan Tang Song-he Song 《应用数学学报(英文版)》2007,23(2):303-310
In this paper,we use Daubechies scaling functions as test functions for the Galerkin method,and discuss Wavelet-Galerkin solutions for the Hamilton-Jacobi equations.It can be proved that the schemesare TVD schemes.Numerical tests indicate that the schemes are suitable for the Hamilton-Jacobi equations.Furthermore,they have high-order accuracy in smooth regions and good resolution of singularities. 相似文献
173.
Arup Baksi Bidyut Kumar Roy Rasajit Kumar Bera 《Mathematical and Computer Modelling》2006,44(11-12):1069-1079
The fundamental equations of the problems of generalized thermoelasticity with one relaxation parameter including heat sources in infinite rotating magneto-thermo-viscoelastic media have been derived in the form of a vector matrix differential equation in the Laplace transform domain for a one dimensional problem. These equations have been solved by the eigenvalue approach to determine deformations, stress, and temperature. The results have been compared to those available in the existing literature. The graphs have been drawn to show the effect of rotation in the medium. 相似文献
174.
Long JIANG 《数学年刊B辑(英文版)》2006,27(5):553-564
Abstract
Under the Lipschitz assumption and square integrable assumption on g, the author proves that Jensen’s inequality holds for backward stochastic differential equations with generator g if and only if g is independent of y, g(t, 0) ≡ 0 and g is super homogeneous with respect to z. This result generalizes the known results on Jensen’s inequality for g- expectation in [4, 7–9].
*Project supported by the National Natural Science Foundation of China (No.10325101) and the Science Foundation of China University
of Mining and Technology. 相似文献
175.
Rieko Shimada 《Mathematical Methods in the Applied Sciences》2007,30(3):257-289
We obtain the Lp–Lq maximal regularity of the Stokes equations with Robin boundary condition in a bounded domain in ?n (n?2). The Robin condition consists of two conditions: v ? u=0 and αu+β(T(u, p)v – 〈T(u, p)v, v〉v)=h on the boundary of the domain with α, β?0 and α+β=1, where u and p denote a velocity vector and a pressure, T(u, p) the stress tensor for the Stokes flow and v the unit outer normal to the boundary of the domain. It presents the slip condition when β=1 and non‐slip one when α=1, respectively. The slip condition is appropriate for problems that involve free boundaries. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
176.
A functional equation of nonlinear iterates is discussed on the circle S1 for its continuous solutions and differentiable solutions. By lifting to R, the existence, uniqueness and stability of those solutions are obtained. Techniques of continuation are used to guarantee the preservation of continuity and differentiability in lifting. 相似文献
177.
Antoni Leon Dawidowicz Najemedin Haribash Anna Poskrobko 《Mathematical Methods in the Applied Sciences》2007,30(7):779-787
The problem of the existence of the invariant measure is important considering its connections with chaotic behaviour. In the papers (Zesz. Nauk. Uniw. Jagiellońskiego, Pr. Mat. 1982; 23 :117–123; Ann. Pol. Math. 1983; XLI :129–137; J. Differential Equations 2004; 196 :448–465) the existence of invariant and ergodic measures according to the dynamical system generated by the Lasota equation was proved, i.e. the equation describing the dynamics and becoming different of the population of cells. In this paper, the existence of such measure for the quasi‐linear Lasota equation is proved. This measure is the carriage of the measure described by Dawidowicz (Zesz. Nauk. Uniw. Jagiellońskiego, Pr. Mat. 1982; 23 :117–123). Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
178.
A nonclassical problem is considered for the transport equation with coefficients depending on the energy of radiation. The task is to find the discontinuity surfaces for the coefficients of the equation from measurements of the radiation flux leaving the medium. For this tomography problem, an optimization problem is stated and numerically analyzed. The latter consists in determining the radiation energy that ensures the best reconstruction of the unknown medium. A simplified optimization problem is solved analytically. 相似文献
179.
赵丽琴 《数学物理学报(B辑英文版)》2007,(2)
In this article, the author studies the boundedness and convergence for the non-Lienard type differential equation (x|·)=a(y)-f(x) (y|·)=b(y)β(x)-g(x) e(t) where a(y),b(y),f(x),g(x),β(x) are real continuous functions in y∈R or x∈R,β(x)≥0 for all x and e(t) is a real continuous function on R = {t: t≥0} such that the equation has a unique solution for the initial value problem. The necessary and sufficient conditions are obtained and some of the results in the literatures are improved and extended. 相似文献
180.
将散射介质层在z轴方向划分成薄层,用薄层的一阶散射强度、Fourier变换和迭代方法求解散射介质整层的矢量辐射传输(VRT)方程的高阶散射解.该方法将一阶散射与高阶散射迭代结合起来,计算公式简明,可计算高阶迭代解,计算时间少.计算结果与一层均匀散射介质的VRT方程一阶Mueller矩阵解、半空间均匀散射介质二阶Mueller矩阵解、以及离散坐标-特征值特征矢量法的VRT热辐射的数值解作了全面的比较.提出并讨论了非均匀散射层主动与被动VRT方程的高阶解.本计算程序可以通用于非球形粒子多层结构及非均匀介质的散射和热辐射计算.
关键词:
VRT方程
分层
迭代解 相似文献