全文获取类型
收费全文 | 1216篇 |
免费 | 103篇 |
国内免费 | 90篇 |
专业分类
化学 | 72篇 |
晶体学 | 1篇 |
力学 | 335篇 |
综合类 | 27篇 |
数学 | 714篇 |
物理学 | 260篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 10篇 |
2021年 | 17篇 |
2020年 | 13篇 |
2019年 | 31篇 |
2018年 | 23篇 |
2017年 | 27篇 |
2016年 | 39篇 |
2015年 | 27篇 |
2014年 | 41篇 |
2013年 | 74篇 |
2012年 | 54篇 |
2011年 | 48篇 |
2010年 | 50篇 |
2009年 | 66篇 |
2008年 | 66篇 |
2007年 | 76篇 |
2006年 | 69篇 |
2005年 | 66篇 |
2004年 | 59篇 |
2003年 | 72篇 |
2002年 | 64篇 |
2001年 | 45篇 |
2000年 | 42篇 |
1999年 | 57篇 |
1998年 | 42篇 |
1997年 | 34篇 |
1996年 | 27篇 |
1995年 | 12篇 |
1994年 | 22篇 |
1993年 | 36篇 |
1992年 | 18篇 |
1991年 | 12篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 4篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
排序方式: 共有1409条查询结果,搜索用时 15 毫秒
1.
A self-propelled object coupled with an enzyme reaction between urease and urea was investigated at the air/aqueous interface. A plastic object that was fixed to a urease-immobilized filter paper was used as a self-propelled object, termed a urease motor, placed on an aqueous urea solution. The driving force of the urease motor is the difference in the surface tension around the object. Oscillatory motion or no motion was triggered depending on the initial pH of the urea solution. Both the frequency and maximum speed of the oscillatory motion varied depending on the initial pH of the water phase. The mechanisms underlying the oscillatory motion and no motion were discussed in relation to the bell-shaped enzyme activity of urease in the enzyme reaction and the surface tension around the urease motor. 相似文献
2.
We discuss an error estimation procedure for the global error of collocation schemes applied to solve singular boundary value problems with a singularity of the first kind. This a posteriori estimate of the global error was proposed by Stetter in 1978 and is based on the idea of Defect Correction, originally due to Zadunaisky. Here, we present a new, carefully designed modification of this error estimate which not only results in less computational work but also appears to perform satisfactorily for singular problems. We give a full analytical justification for the asymptotical correctness of the error estimate when it is applied to a general nonlinear regular problem. For the singular case, we are presently only able to provide computational evidence for the full convergence order, the related analysis is still work in progress. This global estimate is the basis for a grid selection routine in which the grid is modified with the aim to equidistribute the global error. This procedure yields meshes suitable for an efficient numerical solution. Most importantly, we observe that the grid is refined in a way reflecting only the behavior of the solution and remains unaffected by the unsmooth direction field close to the singular point. 相似文献
3.
WANG Libin 《数学年刊B辑(英文版)》2002,23(4):439-454
The author gets a blow-up result of C1 solution to the Cauchy problem for a first order quasilinear non-strictly hyperbolic system in one space dimension. 相似文献
4.
D. Yafaev 《Proceedings Mathematical Sciences》2002,112(1):245-255
We find an explicit function approximating at high energies the kernel of the scattering matrix with arbitrary accuracy. Moreover,
the same function gives all diagonal singularities of the kernel of the scattering matrix in the angular variables.
This paper is dedicated to Jean-Michel Combes on the occasion of his sixtieth birthday. 相似文献
5.
Oleg Palumbíny 《Czechoslovak Mathematical Journal》2003,53(2):467-477
The paper deals with oscillation criteria of fourth order linear differential equations with quasi-derivatives. 相似文献
6.
Ergodic isospectral theory of the Lax pairs of Euler equations with harmonic analysis flavor 总被引:2,自引:0,他引:2
Y. Charles Li 《Proceedings of the American Mathematical Society》2005,133(9):2681-2687
Isospectral theory of the Lax pairs of both 3D and 2D Euler equations of inviscid fluids is developed. Eigenfunctions are represented through an ergodic integral. The Koopman group and mean ergodic theorem are utilized. Further harmonic analysis results on the ergodic integral are introduced. The ergodic integral is a limit of the oscillatory integral of the first kind.
7.
关于多线性振荡奇异积分在加权Hardy-型空间上的一致估计 总被引:1,自引:0,他引:1
本文对一类具有光滑位相函数的多线性振荡奇异积分算子建立了一致的加权(H^1(R^n),L^1(R^n))估计及一致的加权(HKp(R^n),Kp(R^n)估计。 相似文献
8.
R. Uribe-Vargas 《Functional Analysis and Its Applications》2003,37(3):236-240
On a smooth surface in Euclidean 3-space, we consider vanishing curves whose projections on a given plane are small circles centered at the origin. The bifurcations diagram of a parameter-dependent surface is the set of parameters and radii of the circles corresponding to curves with degenerate flattening points. Solving a problem due to Arnold, we find a normal form of the first nontrivial example of a flattening bifurcation diagram, which contains one continuous invariant. 相似文献
9.
对带有一般实参数第三类Painlevé方程,已有γ<0,δ>0时,解的有界性以及振荡渐近解的表达形式的结论.在本文中,我们给出当δ=0或γ=0时其振荡渐近解的表达形式. 相似文献
10.
考虑具常数特征拟线性双曲型方程,提出一个新的可化约方程组的方法,证明了具常特征方程组Cauchy问题经典解的整体存在性定理.同时构造一些例子说明一些有趣的现象. 相似文献