全文获取类型
收费全文 | 3101篇 |
免费 | 255篇 |
国内免费 | 250篇 |
专业分类
化学 | 358篇 |
晶体学 | 35篇 |
力学 | 262篇 |
综合类 | 69篇 |
数学 | 2222篇 |
物理学 | 660篇 |
出版年
2025年 | 4篇 |
2024年 | 24篇 |
2023年 | 41篇 |
2022年 | 50篇 |
2021年 | 47篇 |
2020年 | 74篇 |
2019年 | 87篇 |
2018年 | 73篇 |
2017年 | 83篇 |
2016年 | 86篇 |
2015年 | 62篇 |
2014年 | 105篇 |
2013年 | 220篇 |
2012年 | 121篇 |
2011年 | 115篇 |
2010年 | 158篇 |
2009年 | 200篇 |
2008年 | 196篇 |
2007年 | 215篇 |
2006年 | 158篇 |
2005年 | 172篇 |
2004年 | 168篇 |
2003年 | 152篇 |
2002年 | 155篇 |
2001年 | 124篇 |
2000年 | 117篇 |
1999年 | 98篇 |
1998年 | 107篇 |
1997年 | 87篇 |
1996年 | 63篇 |
1995年 | 46篇 |
1994年 | 50篇 |
1993年 | 20篇 |
1992年 | 23篇 |
1991年 | 13篇 |
1990年 | 14篇 |
1989年 | 10篇 |
1988年 | 5篇 |
1987年 | 12篇 |
1986年 | 3篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1936年 | 1篇 |
排序方式: 共有3606条查询结果,搜索用时 15 毫秒
131.
Formulas for calculating the sum of singular series corresponding to the number of representations of integers by some quadratic forms in 12 variables with integral coefficient are derived. 相似文献
132.
Strong and limit consistency in finite noncooperative games are studied. A solution is called strongly consistent if it is both consistent and conversely consistent (Ref. 1). We provide sufficient conditions on one-person behavior such that a strongly consistent solution is nonempty. We introduce limit consistency for normal form games and extensive form games. Roughly, this means that the solution can be approximated by strongly consistent solutions. We then show that the perfect and proper equilibrium correspondences in normal form games, as well as the weakly perfect and sequential equilibrium correspondences for extensive form games, are limit consistent. 相似文献
133.
In this paper we study Markovian queueing networks in which the service and the routing characteristics have a particular
form which leads to a product form stationary distribution for the number of customers in the various queues of the network.
We show that if certain transitions are prohibited due to blocking conditions, then the form of the stationary distribution
is preserved under a certain rerouting protocol. Several examples are presented which illustrate the wide applicability of
the model.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
134.
Alexander O. Ignatyev 《Journal of Mathematical Analysis and Applications》2011,373(1):343-344
We show that the proof of the results obtained in the above paper is wrong since it is based on lemma which is not true. Therefore the results of the paper cannot be considered as true ones. 相似文献
135.
讨论了拟线性微分代数方程在一类特殊的奇点-拟障碍点附近的标准形.通过矩阵广义逆理论,拟线性微分代数方程可化为半显式形式.然后运用标准形理论,在微分同胚变换下,给出了拟线性微分代数方程在拟障碍点附近的标准形.在此基础上进一步讨论了这类标准形的去奇异化性质. 相似文献
136.
研究非时变有向通讯网络背景下一阶线性多个体动力学系统的整体行为.根据通讯网络的结构,系统可以区分为独立基本子系统和非独立基本子系统.当系统的控制规则为一类平凡的线性类型时,系统的独立基本子系统将趋于自身的一致状态,也即子系统中的每个个体趋于子系统的带权中心.独立基本子系统带权中心由子系统的系数矩阵的零特征根归一化左特征向量确定.非独立子系统中个体将趋于独立基本子系统带权中心的凸集内.当且仅当系统的独立基本子系统唯一时,系统实现一致性行为. 相似文献
137.
W. Melnitchouk 《The European Physical Journal A - Hadrons and Nuclei》2003,17(2):223-234
We explore the relationship between exclusive and inclusive electromagnetic scattering from the pion, focusing on the transition
region at intermediate Q2. Combining Drell-Yan data on the leading twist quark distribution in the pion with a model for the resonance region at large
x, we calculate QCD moments of the pion structure function over a range of Q2, and quantify the role of higher twist corrections. Using a parameterization of the pion elastic form factor and phenomenological
models for the π↦ρ transition form factor, we further test the extent to which local duality may be valid for the pion.
Received: 10 February 2003 / Accepted: 12 March 2003 / Published online: 27 May 2003 相似文献
138.
In this paper we study queueing networks which allow multiple changes at a given time. The model has a natural application
to discrete-time queueing networks but describes also queueing networks in continuous time.
It is shown that product-form results which are known to hold when there are single changes at a given instant remain valid
when multiple changes are allowed. 相似文献
139.
N. Bayer 《Queueing Systems》1996,23(1-4):293-300
This note is concerned with the identification of the Wiener-Hopf factors of a function 1–f, wheref generates an aperiodic distribution on the integers with a negative mean. The general and rational cases are addressed. We give a concise summary of the main practical facts needed for calculations involving the Wiener-Hopf factors. The basic facts are cited from the literature, but a few aspects are briefly proven here.Supported by the European grant BRA-QMIPS of CEC DG XIII. 相似文献
140.
N. Kjurkchiev 《BIT Numerical Mathematics》1996,36(1):182-186
We give an alternative formulation of Le Verrier-Fadeev's method in terms of the Weierstrass root-finding method. Some computational aspects are discussed.This paper is partially supported by the Bulgarian Ministry of Science and Education, Contract MM-515/95. 相似文献