全文获取类型
收费全文 | 406篇 |
免费 | 30篇 |
国内免费 | 32篇 |
专业分类
化学 | 49篇 |
力学 | 13篇 |
综合类 | 9篇 |
数学 | 360篇 |
物理学 | 37篇 |
出版年
2024年 | 1篇 |
2023年 | 9篇 |
2022年 | 6篇 |
2021年 | 12篇 |
2020年 | 12篇 |
2019年 | 12篇 |
2018年 | 13篇 |
2017年 | 11篇 |
2016年 | 18篇 |
2015年 | 8篇 |
2014年 | 24篇 |
2013年 | 32篇 |
2012年 | 15篇 |
2011年 | 17篇 |
2010年 | 17篇 |
2009年 | 19篇 |
2008年 | 31篇 |
2007年 | 27篇 |
2006年 | 19篇 |
2005年 | 21篇 |
2004年 | 19篇 |
2003年 | 21篇 |
2002年 | 13篇 |
2001年 | 9篇 |
2000年 | 14篇 |
1999年 | 13篇 |
1998年 | 19篇 |
1997年 | 10篇 |
1996年 | 6篇 |
1995年 | 8篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1992年 | 4篇 |
1991年 | 2篇 |
1989年 | 1篇 |
1981年 | 1篇 |
1979年 | 2篇 |
排序方式: 共有468条查询结果,搜索用时 218 毫秒
41.
Steven Holdcroft 《Journal of Polymer Science.Polymer Physics》1991,29(13):1585-1588
Intrinsic viscosities and gel permeation chromatography data were used to evaluate the Mark–Houwink constants of the soluble electronically conducting polymer, poly(3-hexylthiophene) (P3HT):K and a are 2.28 × 10-3 cm3/g and 0.96, respectively, in tetrahydrofuran (THF) at 25°C. Mark–Houwink constants were used to calibrate gel permeation chromatography (GPC) columns for P3HT. Number-average molecular weights of P3HT determined with modified calibration curves agreed well with those determined by an absolute method, embulliometry. Molecular weights estimated using unmodified polystyrene calibration procedures were significantly larger than true values. 相似文献
42.
43.
Hans Georg Schaathun 《Designs, Codes and Cryptography》2004,31(1):27-42
A greedy 1-subcode is a one-dimensional subcode of minimum (support) weight. A greedy r-subcode is an r-dimensional subcode with minimum support weight under the constraint that it contain a greedy (r - 1)-subcode. The r-th greedy weight e
r is the support weight of a greedy r-subcode. The greedy weights are related to the weight hierarchy. We use recent results on the weight hierarchy of product codes to develop a lower bound on the greedy weights of product codes. 相似文献
44.
Orthogonal polynomials for exponential weights on 总被引:4,自引:4,他引:0
Let I=[0,d), where d is finite or infinite. Let , where and Q is continuous and increasing on I, with limit ∞ at d. We study the orthonormal polynomials associated with the weight , obtaining bounds on the orthonormal polynomials, zeros, and Christoffel functions. In addition, we obtain restricted range inequalities. 相似文献
45.
Let be a bounded domain with C
2 boundary. And let H
k
be the set of all polyharmonic functions f with order k on Ω. For 0<p, q≤∞ and ϕ a normal weight, the mixed-norm space consists of all function f in H
k
for which the mixed-norm ||·||
p, q, ϕ
<∞. The main result of the paper is the norm equivalence:
where x
0 is a fixed point in Ω, m is a positive integer and is the jth gradient of f. A similar result for Bloch-type spaces is also obtained.
This research is partially supported by the National Natural Science Foundation of China (10471039), the MNZŽS Grant No. 144010
(Serbia), and the Natural Science Foundation of Zhejiang Province (M103104). 相似文献
46.
Yutaka Yoshii 《代数通讯》2017,45(1):1-8
Let G be a connected, semisimple, and simply connected algebraic group defined and split over the finite field of order p, and let G(q) be the corresponding finite Chevalley or twisted group, where q = pr. Recently, Anwar determines the direct sum decomposition of the tensor product of the rth Steinberg module and a simple G-module with a (p,r)-minuscule highest weight λ. In this paper, we determine that of the tensor product regarded as a module for G(q) under some weak assumptions for λ. 相似文献
47.
48.
This paper is devoted to studying the commutators of the multilinear singular integral operators with the non-smooth kernels
and the weighted Lipschitz functions. Some mapping properties for two types of commutators on the weighted Lebesgue spaces,
which extend and generalize some previous results, are obtained. 相似文献
49.
称Boole矩阵A是正规的,是指A的行秩与列秩相等.本文主要得到两个结果.第一,推广了J.Konieczny在SemigroupForum,vol.44(1992)发表的论文Oncardina-litiesofrowspaceofBooleanmatrices的主要结果.第二,若n阶Boole矩阵的行空间基数大于2 ̄(n-2)-2,则A必是正规的. 相似文献
50.
We study two indeterminate Hamburger moment problems and the corresponding orthogonal polynomials. The coefficients in their
recurrence relations are of exponential growth or are polynomials of degree 2. The entire functions in the Nevanlinna parametrization
are found. The orthogonal polynomials with polynomial recurrence coefficients resemble the Freud polynomials with a = 1/2 . Inequalities are given for the largest zero and the asymptotic behavior of the largest zero is established.
April 24, 1996. Date revised: March 3, 1997. 相似文献