全文获取类型
收费全文 | 304篇 |
免费 | 9篇 |
专业分类
化学 | 106篇 |
力学 | 3篇 |
数学 | 154篇 |
物理学 | 50篇 |
出版年
2022年 | 4篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 8篇 |
2015年 | 6篇 |
2014年 | 5篇 |
2013年 | 8篇 |
2012年 | 10篇 |
2011年 | 11篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 17篇 |
2007年 | 21篇 |
2006年 | 14篇 |
2005年 | 10篇 |
2004年 | 6篇 |
2003年 | 14篇 |
2002年 | 4篇 |
2001年 | 9篇 |
2000年 | 7篇 |
1999年 | 5篇 |
1998年 | 8篇 |
1997年 | 7篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 6篇 |
1992年 | 11篇 |
1991年 | 4篇 |
1990年 | 4篇 |
1989年 | 4篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 9篇 |
1985年 | 10篇 |
1984年 | 4篇 |
1983年 | 6篇 |
1982年 | 2篇 |
1981年 | 3篇 |
1979年 | 2篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1972年 | 1篇 |
1969年 | 1篇 |
1967年 | 3篇 |
1966年 | 2篇 |
1965年 | 1篇 |
1913年 | 2篇 |
排序方式: 共有313条查询结果,搜索用时 343 毫秒
31.
We consider a canonical Ramsey type problem. An edge‐coloring of a graph is called m‐good if each color appears at most m times at each vertex. Fixing a graph G and a positive integer m, let f(m, G) denote the smallest n such that every m‐good edge‐coloring of Kn yields a properly edge‐colored copy of G, and let g(m, G) denote the smallest n such that every m‐good edge‐coloring of Kn yields a rainbow copy of G. We give bounds on f(m, G) and g(m, G). For complete graphs G = Kt, we have c1mt2/ln t ≤ f(m, Kt) ≤ c2mt2, and cmt3/ln t ≤ g(m, Kt) ≤ cmt3/ln t, where c1, c2, c, c are absolute constants. We also give bounds on f(m, G) and g(m, G) for general graphs G in terms of degrees in G. In particular, we show that for fixed m and d, and all sufficiently large n compared to m and d, f(m, G) = n for all graphs G with n vertices and maximum degree at most d. © 2003 Wiley Periodicals, Inc. Random Struct. Alg., 2003 相似文献
32.
33.
34.
Noga Alon 《Journal of Graph Theory》1986,10(1):123-127
We show that every graph G on n vertices with minimal degree at least n/k contains a cycle of length at least [n/(k ? 1)]. This verifies a conjecture of Katchalski. When k = 2 our result reduces to the classical theorem of Dirac that asserts that if all degrees are at least 1/2n then G is Hamiltonian. 相似文献
35.
By using the probabilistic method, we show that the maximum number of directed Hamiltonian paths in a complete directed graph with n vertices is at least (e?o(1)) (n!/2n?1). © 2001 John Wiley & Sons, Inc. Random Struct. Alg., 18: 291–296, 2001 相似文献
36.
In this paper we present a pneumatically driven Stewart platform as a basis for motion simulators. Motion platforms, that simulate perceived situations in aeroplanes, cars or ships, have workspace constraints in every degree of freedom. Therefore it is necessary to adapt the accelerations and angular rates in order to stay within the physical restrictions. For realizing a flight or ride simulator on the basis of the Stewart platform, “ Washout Filters” are used to change the signals of the open source software FlightGearand to minimize the sensation error between simulator and aircraft. Different filter concepts are implemented and evaluated. The platform presented in this document is a parallel kinematic robot, driven by fluidic muscles. The pneumatically actuated muscles are only able to produce tensile forces. Therefore a spiral spring from a passenger car is used to apply the compressive forces and torques. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
37.
38.
Klemens Kappel 《Acta Analytica》2010,25(2):175-194
The aim of the paper is to state a version of epistemic expressivism regarding knowledge, and to suggest how this expressivism
about knowledge explains the value of knowledge. The paper considers how an account of the value of knowledge based on expressivism
about knowledge responds to the Meno Problem, the Swamping Problem, and a variety of other questions that pertains to the
value of knowledge, and the role of knowledge in our cognitive ecology. 相似文献
39.
Noga Alon 《Israel Journal of Mathematics》1991,73(2):247-256
It is shown that there exists a function∈(k) which tends to 0 ask tends to infinity, such that anyk-regular graph onn vertices contains at most 2(1/2+∈(k))n
independent sets. This settles a conjecture of A. Granville and has several applications in Combinatorial Group Theory.
Research supported in part by the United States-Israel Binational Science Foundation and by a Bergmann Memorial Grant. 相似文献
40.