全文获取类型
收费全文 | 1264篇 |
免费 | 60篇 |
国内免费 | 173篇 |
专业分类
化学 | 50篇 |
晶体学 | 2篇 |
力学 | 59篇 |
综合类 | 28篇 |
数学 | 1211篇 |
物理学 | 147篇 |
出版年
2024年 | 2篇 |
2023年 | 7篇 |
2022年 | 14篇 |
2021年 | 27篇 |
2020年 | 29篇 |
2019年 | 26篇 |
2018年 | 39篇 |
2017年 | 47篇 |
2016年 | 24篇 |
2015年 | 23篇 |
2014年 | 28篇 |
2013年 | 229篇 |
2012年 | 31篇 |
2011年 | 46篇 |
2010年 | 66篇 |
2009年 | 64篇 |
2008年 | 89篇 |
2007年 | 64篇 |
2006年 | 66篇 |
2005年 | 72篇 |
2004年 | 63篇 |
2003年 | 66篇 |
2002年 | 59篇 |
2001年 | 49篇 |
2000年 | 46篇 |
1999年 | 51篇 |
1998年 | 28篇 |
1997年 | 31篇 |
1996年 | 23篇 |
1995年 | 21篇 |
1994年 | 14篇 |
1993年 | 17篇 |
1992年 | 5篇 |
1991年 | 10篇 |
1990年 | 2篇 |
1989年 | 3篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 2篇 |
1979年 | 3篇 |
1977年 | 1篇 |
排序方式: 共有1497条查询结果,搜索用时 171 毫秒
61.
关于Fuzzy Drazin子半群 总被引:2,自引:0,他引:2
本文引进了FuzzyDrazin子半群的概念,并讨论了它们的一些代数性质,改进并推广了[5]、[6]、[8]、[10]及[11]中的许多重要结果 相似文献
62.
本文先给出Fuzy半群中极小Fuzy理想的一些代数性质,进而利用极小Fuzy理想刻划Fuzzy单半群的一些代数性质 相似文献
63.
Robert Gilmer William Heinzer Moshe Roitman 《Proceedings of the American Mathematical Society》1999,127(11):3141-3151
Suppose is a maximal ideal of a commutative integral domain and that some power of is finitely generated. We show that is finitely generated in each of the following cases: (i) is of height one, (ii) is integrally closed and , (iii) is a monoid domain over a field , where is a cancellative torsion-free monoid such that , and is the maximal ideal . We extend the above results to ideals of a reduced ring such that is Noetherian. We prove that a reduced ring is Noetherian if each prime ideal of has a power that is finitely generated. For each with , we establish existence of a -dimensional integral domain having a nonfinitely generated maximal ideal of height such that is -generated.
64.
也谈理想气体定义——兼对“理想气体的定义”一文质疑 总被引:4,自引:1,他引:3
主张为物质的理想模型下定义时要注意实验基础,在不同的数学阶段使用不同的理想气体定义,文中分析了从玻意耳-马略特定律导出焦耳定律某些方法的缺陷,指出了合理的证明方法。 相似文献
65.
Alberto Corso William Heinzer Craig Huneke 《Transactions of the American Mathematical Society》1998,350(12):5095-5109
We study content ideals of polynomials and their behavior under multiplication. We give a generalization of the Lemma of Dedekind-Mertens and prove the converse under suitable dimensionality restrictions.
66.
Salvatore Sessa 《Fuzzy Sets and Systems》1984,13(1):95-100
In this communication, we explicitly point out that the principal results of Liu 1982 basically deduced from the definition of binary operation ° on the set F(X) of all fuzzy subsets of X, also hold if one uses the weaker definition of product under triangular norm °t. Fuzzy ideals with respect to the triangular norms are also defined. 相似文献
67.
满足右零化子特殊升链条件的环 总被引:1,自引:0,他引:1
本文讨论了满足右零化子特殊升链条件的环的性质以及与左、右完备环,QF-环的关系;给出了满足右零化子特殊升链条件的环中素理想是完全素理想的条件,从而给出了Goldie定理的一个应用. 相似文献
68.
Takashi Shioya 《Geometriae Dedicata》2004,103(1):1-32
We study the behavior of maximal geodesics in a finitely connected complete two-dimensional Riemannian manifold M admitting curvature at infinity. In the case where M is homeomorphic to 2 the Cohn–Vossen theorem states that the total curvature of M, say c(M), is 2. We already studied the case c(M)<2 in our previous paper. So we study the behavior of geodesics in M with total curvature 2 in this paper. Next we consider the case where M has nonempty boundary. In order to know the behavior of distant geodesics in M with boundary, it is useful to investigate the 'visual image' of the boundary of M. The latter half of this paper will be spent to study the asymptotic behavior of the visual image of a subset of M with located point tending to infinity. 相似文献
69.
We study the problem of completely describing the domains that enjoy the generalized multiplicative inequalities of the embedding theorem type. We transfer the assertions for the Sobolev spaces L
p
1() to the function classes that result from the replacement of L
p
() with an ideal space of vector-functions. We prove equivalence of the functional and geometric inequalities between the norms of indicators and the capacities of closed subsets of . The most comprehensible results relate to the case of the rearrangement invariant ideal spaces. 相似文献
70.
Alexander Postnikov Boris Shapiro 《Transactions of the American Mathematical Society》2004,356(8):3109-3142
For a graph , we construct two algebras whose dimensions are both equal to the number of spanning trees of . One of these algebras is the quotient of the polynomial ring modulo certain monomial ideal, while the other is the quotient of the polynomial ring modulo certain powers of linear forms. We describe the set of monomials that forms a linear basis in each of these two algebras. The basis elements correspond to -parking functions that naturally came up in the abelian sandpile model. These ideals are instances of the general class of monotone monomial ideals and their deformations. We show that the Hilbert series of a monotone monomial ideal is always bounded by the Hilbert series of its deformation. Then we define an even more general class of monomial ideals associated with posets and construct free resolutions for these ideals. In some cases these resolutions coincide with Scarf resolutions. We prove several formulas for Hilbert series of monotone monomial ideals and investigate when they are equal to Hilbert series of deformations. In the appendix we discuss the abelian sandpile model.