全文获取类型
收费全文 | 790篇 |
免费 | 24篇 |
国内免费 | 4篇 |
专业分类
化学 | 482篇 |
晶体学 | 1篇 |
力学 | 23篇 |
数学 | 157篇 |
物理学 | 155篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 21篇 |
2020年 | 9篇 |
2019年 | 16篇 |
2018年 | 11篇 |
2017年 | 12篇 |
2016年 | 37篇 |
2015年 | 11篇 |
2014年 | 12篇 |
2013年 | 26篇 |
2012年 | 33篇 |
2011年 | 38篇 |
2010年 | 34篇 |
2009年 | 27篇 |
2008年 | 27篇 |
2007年 | 32篇 |
2006年 | 35篇 |
2005年 | 21篇 |
2004年 | 22篇 |
2003年 | 20篇 |
2002年 | 22篇 |
2001年 | 19篇 |
2000年 | 11篇 |
1999年 | 11篇 |
1998年 | 11篇 |
1997年 | 8篇 |
1996年 | 7篇 |
1995年 | 12篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1988年 | 8篇 |
1985年 | 6篇 |
1984年 | 5篇 |
1983年 | 8篇 |
1982年 | 5篇 |
1981年 | 7篇 |
1978年 | 7篇 |
1976年 | 7篇 |
1973年 | 7篇 |
1963年 | 7篇 |
1962年 | 29篇 |
1961年 | 14篇 |
1957年 | 7篇 |
1956年 | 10篇 |
1955年 | 11篇 |
1954年 | 8篇 |
1951年 | 5篇 |
1937年 | 5篇 |
1913年 | 5篇 |
排序方式: 共有818条查询结果,搜索用时 15 毫秒
1.
Mart Abel 《Rendiconti del Circolo Matematico di Palermo》2005,54(3):409-429
It is shown, that the category ℰ
A
(X) ofA-bundles over a topological spaceX is an additive pseudo-Abelian category for each Waelbroeck algebraA.
This research was supported by Greek State Scholarship Foundation and Estonian Science Foundation grant 6205. 相似文献
2.
K.B. Welter Q. Wu Y. You K. Abel D. McCreary S.M. Bajorek J.N. Reyes Jr 《International Journal of Multiphase Flow》2004,30(12):407-1484
This article describes a comprehensive literature review of liquid entrainment in horizontal pipes with vertical-up branches. Deficiencies in the available data and correlations were identified. The Air–water Test Loop for Advanced Thermal–hydraulic Studies (ATLATS) was constructed and entrainment onset and steady-state data were collected for a wide range of flow conditions. Using new insights gained from experimental testing, the authors developed a model for predicting the onset of entrainment and steady-state entrainment rate. Previously published correlations, along with the new model, are compared against all available data. The new model shows very good agreement with the onset data, but is not very good at predicting branch quality at high liquid flow rates. 相似文献
3.
4.
CV Tomy D Pal SS Banerjee S Ramakrishnan AK Grover S Bhattacharya MJ Higgins G Balakrishnan McK Paul 《Pramana》2002,58(5-6):925-935
The weakly pinned single crystals of the hexagonal 2H-NbSe2 compound have emerged as prototypes for determining and characterizing the phase boundaries of the possible order-disorder
transformations in the vortex matter. We present here a status report based on the ac and dc magnetization measurements of
the peak effect phenomenon in three crystals of 2H-NbSe2, in which the critical current densities vary over two orders of magnitude. We sketch the generic vortex phase diagram of
a weakly pinned superconductor, which also utilizes theoretical proposals. We also establish the connection between the metastability
effects and pinning. 相似文献
5.
In this paper, three new direct Mutually Orthogonal Latin Squares (MOLS) constructions are presented for 7 MOLS(24), 7 MOLS(75) and 8 MOLS(36); then using recursive methods, several new constructions for 7 and 8 MOLS are obtained. These reduce the largest value for which 7 MOLS are unknown from 780 to 570, and the largest odd value for which 8 MOLS are unknown from 1935 to 419. © 2003 Wiley Periodicals, Inc. 相似文献
6.
Surface free energy of a solid surface gives a direct measure of intermolecular interactions at interfaces and has a strong influence on adsorption and adhesion behaviour. However few data are available for the surface free energies of electroless Ni–P based composition coatings. In this paper, the electroless Ni–P, Ni–P-surfactant, Ni–Cu–P, Ni–P–PTFE and Ni–Cu–P–PTFE composite coatings were prepared under various coating conditions. The chemical compositions, surface morphology and thickness of the coatings were measured using an energy dispersive X-ray microanalysis (EDX), a scanning electron microscope (SEM) and a digital micrometer respectively. The contact angles of water, diiodomethane and ethylene glycol on the coatings were measured automatically using dataphysics OCA-20 contact angle analyser. The surface free energy of the coatings and their components (e.g. dispersion, polar or acid/base portions) were calculated using various methods. The experimental results showed that the incorporation of surfactant or PTFE particles into Ni–P matrixes has a significant influence on the surface free energy of the coatings, while the incorporation of copper into Ni–P matrixes has no significant influence on the surface free energy of the coatings. 相似文献
7.
8.
M. Abel 《Journal of Mathematical Sciences》2007,140(3):346-353
Bounded representations of bornological algebras are considered. The left and right bornological radicals in bornological
algebras are introduced. It is shown that the left (right) bornological radical of a bornological algebra A is equal to the
intersection of all bornologically closed maximal regular left (respectively, right) ideals of A, and both these radicals
of A and the Jacobson radical of A coincide if A is an advertive and simplicial bornological algebra (in particular, a bornological
Q-algebra). Bibliography: 16 titles.
Published in Zapiski Nauchnykh Seminarov POMI, Vol. 326, 2005, pp. 9–22. 相似文献
9.
We obtain the complete asymptotic expansion of the image functions of Müller’s Gamma operators and of their derivatives. All expansion coefficients are explicitly calculated. Moreover, we study linear combinations of Gamma operators having a better degree of approximation than the operators themselves. Using divided differences we define general classes of linear combinations of which special cases were recently introduced and investigated by other authors. 相似文献
10.
In this paper a new sheaf for topological algebras, called the sheaf of extendible ideals, is introduced. It is shown that
the sheaf space of this sheaf is uniformizable but not complete in general.
The research of both of the authors was supported by Estonian Science Foundation grant 6205. 相似文献