全文获取类型
收费全文 | 3071篇 |
免费 | 228篇 |
国内免费 | 321篇 |
专业分类
化学 | 86篇 |
力学 | 137篇 |
综合类 | 89篇 |
数学 | 2996篇 |
物理学 | 312篇 |
出版年
2024年 | 2篇 |
2023年 | 52篇 |
2022年 | 57篇 |
2021年 | 62篇 |
2020年 | 96篇 |
2019年 | 84篇 |
2018年 | 98篇 |
2017年 | 92篇 |
2016年 | 98篇 |
2015年 | 50篇 |
2014年 | 123篇 |
2013年 | 278篇 |
2012年 | 107篇 |
2011年 | 159篇 |
2010年 | 144篇 |
2009年 | 183篇 |
2008年 | 183篇 |
2007年 | 205篇 |
2006年 | 203篇 |
2005年 | 181篇 |
2004年 | 139篇 |
2003年 | 129篇 |
2002年 | 146篇 |
2001年 | 108篇 |
2000年 | 103篇 |
1999年 | 104篇 |
1998年 | 84篇 |
1997年 | 60篇 |
1996年 | 54篇 |
1995年 | 44篇 |
1994年 | 39篇 |
1993年 | 21篇 |
1992年 | 17篇 |
1991年 | 10篇 |
1990年 | 13篇 |
1989年 | 5篇 |
1988年 | 8篇 |
1987年 | 7篇 |
1986年 | 17篇 |
1985年 | 16篇 |
1984年 | 6篇 |
1983年 | 9篇 |
1982年 | 7篇 |
1981年 | 5篇 |
1979年 | 1篇 |
1978年 | 4篇 |
1976年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1957年 | 3篇 |
排序方式: 共有3620条查询结果,搜索用时 187 毫秒
11.
周治修 《浙江大学学报(理学版)》2004,31(6):610-613
ZULLI L首先构造了一个用于计算纽结Kauffman尖括号多项式的模2矩阵,纽结的trip矩阵.为了构造链环的trip矩阵,引入了一个带标识的穿有m个孔的圆盘来取代纽结情形下的圆盘,其中m为链环的分支数.主要结果为:定理若状态S是从状态AA…A经过i1,i2,…,ip位置上的标记替换(A换成B)而得的状态.设Ts是将trip矩阵T的左上角的n×n子块中ai1i1,ai2i2,…,aipip之值进行替换(0→1或1→0)所得的矩阵,则#(L|S)=n+m-秩(Ts).因此计算链环Kauffman尖括号多项式就归结为计算一组模2矩阵的秩. 相似文献
12.
13.
We study conditions on the matrix mask of a vector subdivision scheme ensuring that certain polynomial input vectors yield polynomial output again. The conditions are in terms of a recurrence formula for the vectors which determine the structure of polynomial input with this property. From this recurrence, we obtain an algorithm to determine polynomial input of maximal degree. The algorithm can be used in the design of masks to achieve a high order of polynomial reproduction. 相似文献
14.
15.
On Polynomial Functions over Finite Commutative Rings 总被引:1,自引:0,他引:1
Jian Jun JIANG Guo Hua PENG Qi SUN Qi Fan ZHANG 《数学学报(英文版)》2006,22(4):1047-1050
Let R be an arbitrary finite commutative local ring. In this paper, we obtain a necessary and sufficient condition for a function over R to be a polynomial function. Before this paper, necessary and sufficient conditions for a function to be a polynomial function over some special finite commutative local rings were obtained. 相似文献
16.
Jaeyoung Chung 《Journal of Mathematical Analysis and Applications》2004,300(2):376-350
We reformulate and prove the Hyers–Ulam–Rassias stability of Cauchy equation in the space of Schwartz tempered distributions and Fourier hyperfunctions. 相似文献
17.
Gabriela Jeronimo Teresa Krick Juan Sabia Martín Sombra 《Foundations of Computational Mathematics》2004,4(1):41-117
We present a bounded probability algorithm for the computation of the
Chowforms of the equidimensional components of an algebraic variety. In particular,
this gives an alternative procedure for the effective equidimensional decomposition
of the variety, since each equidimensional component is characterized by its Chow
form.
The expected complexity of the algorithm is polynomial in the size and the geometric
degree of the input equation system defining the variety. Hence it improves (or
meets in some special cases) the complexity of all previous algorithms for computing Chow forms. In addition to this, we clarify the probability and uniformity aspects,
which constitutes a further contribution of the paper.
The algorithm is based on elimination theory techniques, in line with the geometric
resolution algorithm due to M. Giusti, J. Heintz, L. M. Pardo, and their collaborators.
In fact, ours can be considered as an extension of their algorithm for zero-dimensional
systems to the case of positive-dimensional varieties. The key element for dealing
with positive-dimensional varieties is a new Poisson-type product formula. This
formula allows us to compute the Chow form of an equidimensional variety from a
suitable zero-dimensional fiber.
As an application, we obtain an algorithm to compute a subclass of sparse resultants,
whose complexity is polynomial in the dimension and the volume of the input
set of exponents. As another application, we derive an algorithm for the computation
of the (unique) solution of a generic overdetermined polynomial equation system. 相似文献
18.
In this paper, we study the linearization of the Cauchy problem and the mixed problem for the system of Grad--Hermite moments in nonequilibrium thermodynamics in the neighborhood of the equilibrium state. Stability conditions for solutions of the Cauchy problem are proved as a generalization of the classical Hermite--Biller theorem on stable polynomials. For the mixed problem, we prove an analog of the Vishik--Lyusternik theorem on small singular perturbations of general elliptic problems. The last observation allows us to introduce the Shapiro--Lopatinskii condition, which implies the well-posedness of the mixed problem. 相似文献
19.
This note investigates two long-standing conjectures on the Krull dimension of integer-valued polynomial rings and of polynomial rings in the context of (locally) essential domains.
20.
Y. Brihaye S. Giller C. Gonera P. Kosinski P. Maslanka 《Czechoslovak Journal of Physics》2004,54(11):1185-1190
The dynamical systems of identical particles admitting quadratic integrals of motion are classified. The relevant integrals are explicitly constructed and their relation to separation of variables in Hamilton-Jacobi equation is clarified. 相似文献