全文获取类型
收费全文 | 11351篇 |
免费 | 1526篇 |
国内免费 | 857篇 |
专业分类
化学 | 691篇 |
晶体学 | 22篇 |
力学 | 1583篇 |
综合类 | 205篇 |
数学 | 8801篇 |
物理学 | 2432篇 |
出版年
2024年 | 22篇 |
2023年 | 158篇 |
2022年 | 180篇 |
2021年 | 261篇 |
2020年 | 424篇 |
2019年 | 388篇 |
2018年 | 385篇 |
2017年 | 492篇 |
2016年 | 392篇 |
2015年 | 296篇 |
2014年 | 574篇 |
2013年 | 969篇 |
2012年 | 499篇 |
2011年 | 679篇 |
2010年 | 521篇 |
2009年 | 610篇 |
2008年 | 678篇 |
2007年 | 673篇 |
2006年 | 648篇 |
2005年 | 601篇 |
2004年 | 498篇 |
2003年 | 482篇 |
2002年 | 479篇 |
2001年 | 373篇 |
2000年 | 345篇 |
1999年 | 326篇 |
1998年 | 311篇 |
1997年 | 265篇 |
1996年 | 191篇 |
1995年 | 148篇 |
1994年 | 147篇 |
1993年 | 95篇 |
1992年 | 77篇 |
1991年 | 63篇 |
1990年 | 60篇 |
1989年 | 38篇 |
1988年 | 40篇 |
1987年 | 35篇 |
1986年 | 39篇 |
1985年 | 35篇 |
1984年 | 40篇 |
1983年 | 20篇 |
1982年 | 38篇 |
1981年 | 29篇 |
1980年 | 22篇 |
1979年 | 14篇 |
1978年 | 20篇 |
1977年 | 11篇 |
1976年 | 8篇 |
1936年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 115 毫秒
71.
徐应祥 《宁波大学学报(理工版)》2007,20(2):206-210
应用三次紧支撑样条小波插值函数得到了求一类常微分方程组数值解的隐式公式,并求得到其局部截断误差为O(-h5).在此基础上给出1个显式校正求解公式,并讨论得到其局部截断误差为O(-h4). 相似文献
72.
Yang Zuosheng 《国际流体数值方法杂志》2005,47(12):1423-1430
A complete boundary integral formulation for compressible Navier–Stokes equations with time discretization by operator splitting is developed using the fundamental solutions of the Helmholtz operator equation with different order. The numerical results for wall pressure and wall skin friction of two‐dimensional compressible laminar viscous flow around airfoils are in good agreement with field numerical methods. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
73.
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
74.
Anatoliy Malyarenko 《Journal of Theoretical Probability》2006,19(2):263-288
We prove a general functional limit theorem for multiparameter fractional Brownian motion. The functional law of the iterated
logarithm, functional Lévy’s modulus of continuity and many other results are its particular cases. Applications to approximation
theory are discussed.
相似文献
75.
D. V. Artamonov 《Mathematical Notes》2007,81(5-6):573-589
A natural criterion for dimensional full-valuedness of locally compact spaces with finitely generated local homology is given. 相似文献
76.
By an elementary calculation we obtain the exact mean values of Minkowksi functionals for a standard model of percolating sets. In particular, a recurrence theorem for the mean Euler characteristic recently put forward is shown to be incorrect. Related previous mathematical work is mentioned. We also conjecture bounds for the threshold density of continuum percolation, which are associated with the Euler characteristic. 相似文献
77.
Daniel FRANCO Gennaro INFANTE Donal O'REGAN 《数学学报(英文版)》2006,22(6):1745-1750
We establish new criteria for the existence of either positive or nonzero solutions of the Urysohn integral equation. We also discuss the existence of an interval of positive eigenvalues and sufficient conditions for the existence of at least a positive eigenvalue with a nonzero or positive eigenfunction for the Urysohn integral operator. Among others, we employ techniques based on fixed point index theory for compact maps, which are new for this type of equation. 相似文献
78.
Summary We study the integration theory for general integral metrics when restricted to upper integrals q, finding improvements in the relation between the classes of the q-integrable and the ql-integrable functions. We give new results and notions which lead to the desirable characterizations of q-integrable functions as ql-integrable f with q(|f|) < ∞, and of ql-integrable functions via the integrability of their upper truncations, under natural conditions which are fulfilled in most
finitely additive integration theories. 相似文献
79.
Youssef Randjiou 《Journal of Theoretical Probability》2006,19(3):701-720
Let μ+(t) and μ−(t) be the locations of the maximum and minimum, respectively, of a standard Brownian motion in the interval [0,t]. We establish a joint integral test for the lower functions of μ+(t) and μ−(t), in the sense of Paul Lévy. In particular, it yields the law of the iterated logarithm for max(μ+(t),μ−(t)) as a straightforward consequence. Our result is in agreement with well-known theorems of Chung and Erdős [(1952) Trans. Amer. Math. Soc. 72, 179–186.], and Csáki, F?ldes and Révész [(1987) Prob. Theory Relat. Fields
76, 477–497].
相似文献
80.
In this paper, we study the consistency of a variant of fractionalstep Runge–Kutta methods. These methods are designed tointegrate efficiently semi-linear multidimensional parabolicproblems by means of linearly implicit time integration processes.Such time discretization procedures are also related to a splittingof the space differential operator (or the spatial discretizationof it) as a sum of simpler linear differentialoperators and a nonlinear term. 相似文献