全文获取类型
收费全文 | 617篇 |
免费 | 61篇 |
国内免费 | 35篇 |
专业分类
化学 | 20篇 |
晶体学 | 2篇 |
力学 | 18篇 |
综合类 | 11篇 |
数学 | 253篇 |
物理学 | 409篇 |
出版年
2024年 | 1篇 |
2023年 | 8篇 |
2022年 | 7篇 |
2021年 | 8篇 |
2020年 | 18篇 |
2019年 | 17篇 |
2018年 | 12篇 |
2017年 | 9篇 |
2016年 | 17篇 |
2015年 | 17篇 |
2014年 | 31篇 |
2013年 | 30篇 |
2012年 | 16篇 |
2011年 | 42篇 |
2010年 | 33篇 |
2009年 | 48篇 |
2008年 | 39篇 |
2007年 | 44篇 |
2006年 | 41篇 |
2005年 | 36篇 |
2004年 | 30篇 |
2003年 | 28篇 |
2002年 | 27篇 |
2001年 | 16篇 |
2000年 | 21篇 |
1999年 | 21篇 |
1998年 | 9篇 |
1997年 | 17篇 |
1996年 | 9篇 |
1995年 | 7篇 |
1994年 | 7篇 |
1993年 | 4篇 |
1992年 | 6篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有713条查询结果,搜索用时 15 毫秒
81.
In 1967 Komlós proved that for any sequence n{fn} in L1(μ), with ‖fn‖?M<∞ (where μ is a probability measure), there exists a subsequence n{gn} of n{fn} and a function g∈L1(μ) such that for any further subsequence n{hn} of n{gn},
82.
83.
精确计算在π~0重整化链图传播下p→p′微分截面 总被引:1,自引:1,他引:0
本文采用中性介子π0与核子N-反核子U-强相互作用的Lorentz不变耦合模型,对质子反质子在中性介子π0重整化链图传播下的散射微分截面,作了严格解析计算后获得了"精确"理论结果;进而,又对该计算结果与π0树图传播下的微分截面作了对比分析,获得了相关辐射修正的重要结果.这对于深入研究质子摊贩质子在高、中、低能区中的弹性碰撞及其描述强相互作用的Lorentz不变耦合模型理论,都将提供某些值得借鉴与参考的理论研究价值. 相似文献
84.
Let Λw,? be the Orlicz–Lorentz space. We study Gateaux differentiability of the functional ψw,? (f) = ? (f *)w and of the Luxemburg norm. More precisely, we obtain the one‐sided Gateaux derivatives in both cases and we characterize those points where the Gateaux derivative of the norm exists. We give a characterization of best ψw,? ‐approximants from convex closed subsets and we establish a relation between best ψw,? ‐approximants and best approximants from a convex set. A characterization of best constant ψw,? ‐approximants and the algorithm to construct the best constant for maximum and minimum ψw,? ‐pproximants are given. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
85.
Apollonian circle packings arise by repeatedly filling the interstices between mutually tangent circles with further tangent
circles. In Euclidean space it is possible for every circle in such a packing to have integer radius of curvature, and we
call such a packing an integral Apollonian circle packing. There are infinitely many different integral packings; these were studied in Part I (J. Number Theory 100, 1–45, 2003). Integral circle packings also exist in spherical and hyperbolic space, provided a suitable definition of curvature is used
and again there are an infinite number of different integral packings. This paper studies number-theoretic properties of such
packings. This amounts to studying the orbits of a particular subgroup
of the group of integral automorphs of the indefinite quaternary quadratic form
. This subgroup, called the Apollonian group, acts on integer solutions
. This paper gives a reduction theory for orbits of
acting on integer solutions to
valid for all integer k. It also classifies orbits for all k≡0 (mod 4) in terms of an extra parameter n and an auxiliary class group (depending on n and k), and studies congruence conditions on integers in a given orbit.
Much of this work was done while the authors were at AT&T Labs-Research, whom the authors thank for support. N. Eriksson was
also supported by an NDSEG fellowship and J.C. Lagarias by NSF grant DMS-0500555. 相似文献
86.
Qi Keng LU Ke WU 《数学学报(英文版)》2007,23(4):577-598
For an integer m ≥ 4, we define a set of 2[m/2] × 2[m/2] matrices γj (m), (j = 0, 1,..., m - 1) which satisfy γj (m)γk (m) +γk (m)γj (m) = 2ηjk (m)I[m/2], where (ηjk (m)) 0≤j,k≤m-1 is a diagonal matrix, the first diagonal element of which is 1 and the others are -1, I[m/2] is a 2[m/1] × 2[m/2] identity matrix with [m/2] being the integer part of m/2. For m = 4 and 5, the representation (m) of the Lorentz Spin group is known. For m≥ 6, we prove that (i) when m = 2n, (n ≥ 3), (m) is the group generated by the set of matrices {T|T=1/√ξ((I+k) 0 + 0 I-K) ( U 0 0 U), (ii) when m = 2n + 1 (n≥ 3), (m) is generated by the set of matrices {T|T=1/√ξ(I -k^- k I)U,U∈ (m-1),ξ=1-m-2 ∑k,j=0 ηkja^k a^j〉0, K=i[m-3 ∑j=0 a^j γj(m-2)+a^(m-2) In],K^-=i[m-3∑j=0 a^j γj(m-2)-a^(m-2) In]} 相似文献
87.
《Physics and Chemistry of Liquids》2012,50(2):160-171
Excess permittivity and excess conductivity of the binary fluid mixture isobutyric acid–water (I–W) have been computed at three temperatures and along the coexistence curve, on the basis of refractive index and electrical conductivity data of the mixture. The other related properties, molar volume, molar refraction and polarisablities have also been reported. The temperature dependence of the molar refraction was also examined. The results have been interpreted in terms of the nature of specific intermolecular interactions between the components. 相似文献
88.
基于包含辐射阻尼效应的电子运动方程,通过坐标变换,分析了圆极化和线极化超强激光在等离子体中传播时,辐射阻尼效应对电子运动的影响。结果表明:两种极化情况下,辐射阻尼效应都随等离子体密度的增大而增强;在圆极化激光中,激光强度在1023~1026 W/cm2范围(对应于不同的等离子体密度)时,辐射阻尼效应将对电子的运动产生显著的反作用,而对于线极化激光,只有当激光强度远大于极限光强时,辐射阻尼效应才对电子的运动有明显的作用。 相似文献
89.
90.