全文获取类型
收费全文 | 5649篇 |
免费 | 592篇 |
国内免费 | 329篇 |
专业分类
化学 | 355篇 |
晶体学 | 9篇 |
力学 | 739篇 |
综合类 | 90篇 |
数学 | 3985篇 |
物理学 | 1392篇 |
出版年
2024年 | 6篇 |
2023年 | 46篇 |
2022年 | 82篇 |
2021年 | 79篇 |
2020年 | 158篇 |
2019年 | 144篇 |
2018年 | 136篇 |
2017年 | 162篇 |
2016年 | 180篇 |
2015年 | 117篇 |
2014年 | 264篇 |
2013年 | 664篇 |
2012年 | 232篇 |
2011年 | 310篇 |
2010年 | 261篇 |
2009年 | 331篇 |
2008年 | 335篇 |
2007年 | 388篇 |
2006年 | 308篇 |
2005年 | 279篇 |
2004年 | 250篇 |
2003年 | 246篇 |
2002年 | 212篇 |
2001年 | 186篇 |
2000年 | 191篇 |
1999年 | 179篇 |
1998年 | 151篇 |
1997年 | 96篇 |
1996年 | 103篇 |
1995年 | 62篇 |
1994年 | 65篇 |
1993年 | 44篇 |
1992年 | 53篇 |
1991年 | 53篇 |
1990年 | 27篇 |
1989年 | 14篇 |
1988年 | 13篇 |
1987年 | 17篇 |
1986年 | 8篇 |
1985年 | 19篇 |
1984年 | 23篇 |
1983年 | 14篇 |
1982年 | 10篇 |
1981年 | 14篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1976年 | 3篇 |
1974年 | 3篇 |
排序方式: 共有6570条查询结果,搜索用时 15 毫秒
91.
Mark C. Veraar 《Proceedings of the American Mathematical Society》2007,135(5):1477-1486
In this paper we prove the equivalence of decoupling inequalities for stochastic integrals and one-sided randomized versions of the UMD property of a Banach space as introduced by Garling.
92.
本文研究了一类中立型时滞差分方程的振动性和正解存在性,获得了该方程所有解振动的“Sharp”条件及存在正解的一个充分条件. 相似文献
93.
Dragan DJURCIC Aleksandar TORGASEV 《数学学报(英文版)》2006,22(3):689-692
In this paper, we prove some properties of the Seneta sequences and functions, and in particular we prove a representation theorem in the Karamata sense for the sequences from the Seneta class SOc. 相似文献
94.
95.
本文对广义风险过程中的渐近方差作了非参数估计,得出并证明了两个定理,为广义风险过程中破产概率的区间估计作了理论准备. 相似文献
96.
The logarithmic norm. History and modern theory 总被引:1,自引:0,他引:1
Gustaf Söderlind 《BIT Numerical Mathematics》2006,46(3):631-652
In his 1958 thesis Stability and Error Bounds, Germund Dahlquist introduced the logarithmic norm in order to derive error bounds in initial value problems, using differential inequalities that distinguished between forward and reverse time integration. Originally defined for matrices, the logarithmic norm can be extended to bounded linear operators, but the extensions to nonlinear maps and unbounded operators have required a functional analytic redefinition of the concept.This compact survey is intended as an elementary, but broad and largely self-contained, introduction to the versatile and powerful modern theory. Its wealth of applications range from the stability theory of IVPs and BVPs, to the solvability of algebraic, nonlinear, operator, and functional equations. In memory of Germund Dahlquist (1925–2005).AMS subject classification (2000) 65L05 相似文献
97.
本文考察一类具耗散的广义KdV方程组■ (gradφ(■))_x ■_(xxx)-α■_(xx) γ■ =■(x,t,■)的周期初值问题的显式差分格式.利用有界延拓法证明了该差分格式的收敛性与稳定性,并给出了算法和数值例子. 相似文献
98.
Marcinkiewicz–Zygmund inequalities 总被引:1,自引:1,他引:0
We study a generalization of the classical Marcinkiewicz–Zygmund inequalities. We relate this problem to the sampling sequences in the Paley–Wiener space and by using this analogy we give sharp necessary and sufficient computable conditions for a family of points to satisfy the Marcinkiewicz–Zygmund inequalities. 相似文献
99.
Three types of resins, related to the spacer, environmental and microenvironmental models were prepared by grafting commercial AMP polymer with 2-[2-(2-aminoethylamino)-2-oxoethoxy]acetic acid. All resins were highly loaded and functionalized with Rink-amide linker. A comparative synthesis of the classic difficult sequence ACP (65-74) on the prepared resins by Fmoc/t-Bu chemistry is presented. The ‘microenviromental’ model resin afforded the crude peptide in the highest purity (98%). 相似文献
100.
K. Osaki T. Inoue T. Uematsu Y. Yamashita 《Journal of Polymer Science.Polymer Physics》2002,40(10):1038-1045
Linear viscoelasticity behavior is described with the sum of two terms for polystyrene solutions in tricresyl phosphate around the coil overlapping concentration (K. Osaki, T. Inoue, & T. Uematsu, J Polym Sci Part B: Polym Phys 2001, 39, 211). One is a Rouse–Zimm (RZ) term represented by the Zimm theory with arbitrarily chosen values of the hydrodynamic interaction parameter and the longest relaxation time (τRZ). The other (the L term) consists of a relaxation mode with a single relaxation time (τL > τRZ) and a high‐frequency limiting modulus proportional to the square of the concentration. In this study, we describe the viscosity (η) and first normal stress coefficient (Ψ1) in steady shear with simple formulas. The stress due to the L term is assumed to be given by a Kaye, Bernstein, Kearsley, and Zapas (K‐BKZ) equation with the damping function h(γ) = (1 + 0.2γ2)?1/2, where γ is the magnitude of shear. Contributions to η and Ψ1 from the RZ term are derived from the RZ model, in which the relaxation time in steady flow is given by τst = τ + (τRZ ? τ)/(1 + 0.35τRZ γ˙) instead of τRZ. Here, γ˙ is the rate of shear, and τ is the τRZ value at the infinite dilution limit. η and Ψ1 at various concentrations for two polystyrene samples (with molecular weights of 2890 and 8420 kg mol?1) are well described with parameters derived from dynamic viscoelasticity. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1038–1045, 2002 相似文献