全文获取类型
收费全文 | 981篇 |
免费 | 47篇 |
国内免费 | 39篇 |
专业分类
化学 | 203篇 |
晶体学 | 5篇 |
力学 | 3篇 |
综合类 | 2篇 |
数学 | 663篇 |
物理学 | 191篇 |
出版年
2023年 | 8篇 |
2022年 | 12篇 |
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 27篇 |
2018年 | 21篇 |
2017年 | 11篇 |
2016年 | 8篇 |
2015年 | 18篇 |
2014年 | 30篇 |
2013年 | 66篇 |
2012年 | 27篇 |
2011年 | 68篇 |
2010年 | 47篇 |
2009年 | 69篇 |
2008年 | 90篇 |
2007年 | 83篇 |
2006年 | 59篇 |
2005年 | 36篇 |
2004年 | 45篇 |
2003年 | 28篇 |
2002年 | 32篇 |
2001年 | 38篇 |
2000年 | 18篇 |
1999年 | 28篇 |
1998年 | 19篇 |
1997年 | 19篇 |
1996年 | 24篇 |
1995年 | 18篇 |
1994年 | 9篇 |
1993年 | 11篇 |
1992年 | 18篇 |
1991年 | 11篇 |
1990年 | 5篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 2篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 3篇 |
1979年 | 2篇 |
1978年 | 6篇 |
1977年 | 1篇 |
1976年 | 4篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 2篇 |
排序方式: 共有1067条查询结果,搜索用时 15 毫秒
41.
The key equations of BiCGStab are summarised to show its connections with Padé and vector-Padé approximation. These considerations lead naturally to stabilised vector-Padé approximation of a vector-valued function (VPAStab), and an algorithm for the acceleration of convergence of a linearly generated sequence of vectors. A generalisation of this algorithm for the acceleration of convergence of a nonlinearly generated system is proposed here, and comparative numerical results are given. 相似文献
42.
43.
An infinite family of q-clans, called the Subiaco q-clans, is constructed for q=2e. Associated with these q-clans are flocks of quadratic cones, elation generalized quadrangles of order (q
2, q), ovals of PG(2, q) and translation planes of order q
2 with kernel GF(q). It is also shown that a q-clan, for q=2e, is equivalent to a certain configuration of q+1 ovals of PG(2, q), called a herd.W. Cherowitzo gratefully acknowledges the support of the Australian Research Council and has the deepest gratitude and warmest regards for the Combinatorial Computing Research Group at the University of Western Australia for their congenial hospitality and moral support. I. Pinneri gratefully acknowledges the support of a University of Western Australia Research Scholarship. 相似文献
44.
This paper considers the prescribed scalar curvature problem onS
n
forn>-3. We consider the limits of solutions of the regularization obtained by decreasing the critical exponent. We characterize those subcritical solutions which blow up at the least possible energy level, determining the points at which they can concentrate, and their Morse indices. We then show that forn=3 this is the only blow up which can occur for solutions. We use this in combination with the Morse inequalities for the subcritical problem to obtain a general existence theorem for the prescribed scalar curvature problem onS
3.This article was processed by the author using the
style filepljourlm from Springer-Verlag. 相似文献
45.
46.
The neutron induced reactions on23 Na are investigated by using the Talys1.4 program. The calculated results for the23Na(n, 2n)22Na reaction are found to agree with the experimental results. The cross sections of the residues of the(n, n),(n, γ),(n, p), and(n, np) channels in the reactions are presented, and at the same time, the neutron induced reactions on22 Ne are also investigated. 相似文献
47.
We investigate the structure of a collineation groupG preserving an oval in a finite projective plane of odd order and we obtain several results aboutG, whenG is a2-group. These results are then used to investigate the structure ofG/O(G) in the general case and, in particular, that ofF*(G/O(G)).This research was supported in part by a grant from the M.U.R.S.T. 相似文献
48.
The neutron induced reactions on ^23Na are investigated by using the Talys1.4 program. The calculated results for the ^23Na(n, 2n)22Na reaction are found to agree with the experimental results. The cross sections of the residues of the(n, n),(n, γ),(n, p), and(n, np) channels in the reactions are presented, and at the same time, the neutron induced reactions on22 Ne are also investigated. 相似文献
49.
K. Kosmidou F. Pasiouras M. Doumpos C. Zopounidis 《Central European Journal of Operations Research》2006,14(1):25-44
Further consolidation takes place not only among UK banks but also across borders, since some banks see size as a key factor
in remaining competitive in international markets. Therefore, it is interesting to investigate the effectiveness and performance
of UK banks. Based on their assets, banks are distinguished into small and large ones and a classification of UK banks in
a multivariate environment for the period 1998–2002 takes place. The PAIRCLAS multicriteria methodology is employed to investigate
the performance of UK small and large banks over multiple criteria, such as asset quality, capital adequacy, liquidity and
efficiency/profitability. A comparison with discriminant analysis (DA) and logistic regression (LR) facilitates the investigation
of the relative performance of PAIRCLAS against them. The results of the study determine the key factors that specify the
classification of a bank as small or large and provide us with the responsible banking decision makers for future readjustments. 相似文献
50.
D. S. Lubinsky 《Constructive Approximation》2002,18(2):285-308
Let a≥ 0 , ɛ >0 . We use potential theory to obtain a sharp lower bound for the linear Lebesgue measure of the set Here P is an arbitrary polynomial of degree ≤ n . We then apply this to diagonal and ray Padé sequences for functions analytic (or meromorphic) in the unit ball. For example,
we show that the diagonal \left{ [n/n]\right}
n=1
∞
sequence provides good approximation on almost one-eighth of the circles centre 0 , and the \left{ [2n/n]\right}
n=1
∞
sequence on almost one-quarter of such circles.
July 18, 2000. Date revised: . Date accepted: April 19, 2001. 相似文献