首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   1769篇
  免费   93篇
  国内免费   162篇
化学   148篇
力学   40篇
综合类   30篇
数学   1621篇
物理学   185篇
  2024年   2篇
  2023年   16篇
  2022年   31篇
  2021年   26篇
  2020年   43篇
  2019年   42篇
  2018年   39篇
  2017年   31篇
  2016年   51篇
  2015年   24篇
  2014年   71篇
  2013年   178篇
  2012年   56篇
  2011年   93篇
  2010年   75篇
  2009年   145篇
  2008年   131篇
  2007年   121篇
  2006年   104篇
  2005年   93篇
  2004年   80篇
  2003年   71篇
  2002年   74篇
  2001年   56篇
  2000年   65篇
  1999年   49篇
  1998年   53篇
  1997年   28篇
  1996年   31篇
  1995年   23篇
  1994年   19篇
  1993年   17篇
  1992年   11篇
  1991年   7篇
  1990年   6篇
  1989年   5篇
  1988年   3篇
  1987年   3篇
  1985年   5篇
  1984年   9篇
  1983年   6篇
  1982年   4篇
  1981年   3篇
  1980年   2篇
  1979年   9篇
  1978年   4篇
  1977年   4篇
  1974年   1篇
  1970年   2篇
  1959年   1篇
排序方式: 共有2024条查询结果,搜索用时 93 毫秒
61.
62.
The partial order on monomials that corresponds to domination when evaluated at positive Newton sequences is fully understood. Here we take up the corresponding partial order on linear combinations of monomials. In part using analysis based upon the cone structure of the exponents in p-Newton sequences, an array of conditions is given for this new partial order. It appears that a characterization in general will be difficult. Within the case in which all coefficients are 1, the situation in which, for general sequence length, there are two monomials, each of length two and nonnegative integer exponents, the partial order is fully characterized. The characterization is combinatorial, in terms of indices in the monomials, and, already here there is much more than term-wise domination.  相似文献   
63.
64.
We consider β-expansions of formal Laurent series over finite fields. If the base β is a Pisot or Salem series, we prove that the β-expansion of a Laurent series α is automatic if and only if α is algebraic.  相似文献   
65.
This article takes a closer look at the problem of approximating the exponential and logarithmic functions using polynomials. Either as an alternative to or a precursor to Taylor polynomial approximations at the precalculus level, interpolating polynomials are considered. A measure of error is given and the behaviour of the error function is analysed. The results of interpolating polynomials are compared with those of Taylor polynomials.  相似文献   
66.
Existence of amplitude independent frequencies of oscillation is an unusual property for a nonlinear oscillator. We find that a class of N coupled nonlinear Liénard type oscillators exhibit this interesting property. We show that a specific subset can be explicitly solved from which we demonstrate the existence of periodic and quasiperiodic solutions. Another set of N coupled nonlinear oscillators, possessing the amplitude independent nature of frequencies, is almost integrable in the sense that the system can be reduced to a single nonautonomous first order scalar differential equation which can be easily integrated numerically.  相似文献   
67.
Incomplete data in soft sets lead to uncertainty and inaccuracy in representing and handling information. This paper introduces notions of complete distance between two objects and relative dominance degree between two parameters. Based on both the notions, an object-parameter method is proposed to predict unknown data in incomplete fuzzy soft sets. The proposal makes full use of known data, including the information from the relationship between known values of all objects on a certain parameter and the information from the relationship between known values of an object on all parameters. The effectiveness of the proposal is verified by many examples under the compared investigation of classical predicted methods.  相似文献   
68.
In Korchmáros et al. (2018)one-factorizations of the complete graph Kn are constructed for n=q+1 with any odd prime power q such that either q1(mod4) or q=2h?1. The arithmetic restriction n=q+1 is due to the fact that the vertices of Kn in the construction are the points of a conic Ω in the finite plane of order q. Here we work on the Euclidean plane and describe an analogous construction where the role of Ω is taken by a regular n-gon. This allows us to remove the above constraints and construct one-factorizations of Kn for every even n6.  相似文献   
69.
70.
In this paper, we investigate the complete moment convergence for dependent linear processes with random coefficients to form  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号