全文获取类型
收费全文 | 3258篇 |
免费 | 140篇 |
国内免费 | 23篇 |
专业分类
化学 | 2285篇 |
晶体学 | 17篇 |
力学 | 181篇 |
数学 | 509篇 |
物理学 | 429篇 |
出版年
2024年 | 5篇 |
2023年 | 26篇 |
2022年 | 37篇 |
2021年 | 63篇 |
2020年 | 80篇 |
2019年 | 68篇 |
2018年 | 50篇 |
2017年 | 36篇 |
2016年 | 103篇 |
2015年 | 105篇 |
2014年 | 138篇 |
2013年 | 167篇 |
2012年 | 281篇 |
2011年 | 289篇 |
2010年 | 182篇 |
2009年 | 151篇 |
2008年 | 215篇 |
2007年 | 206篇 |
2006年 | 179篇 |
2005年 | 158篇 |
2004年 | 159篇 |
2003年 | 141篇 |
2002年 | 148篇 |
2001年 | 42篇 |
2000年 | 41篇 |
1999年 | 39篇 |
1998年 | 18篇 |
1997年 | 30篇 |
1996年 | 32篇 |
1995年 | 20篇 |
1994年 | 19篇 |
1993年 | 17篇 |
1992年 | 15篇 |
1991年 | 8篇 |
1990年 | 5篇 |
1989年 | 10篇 |
1987年 | 5篇 |
1986年 | 7篇 |
1985年 | 11篇 |
1984年 | 6篇 |
1983年 | 8篇 |
1982年 | 9篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 4篇 |
1977年 | 6篇 |
1976年 | 7篇 |
1968年 | 15篇 |
1967年 | 9篇 |
排序方式: 共有3421条查询结果,搜索用时 15 毫秒
1.
Olivier Penacchio 《Comptes Rendus Mathematique》2002,335(5):475-480
Let X be a smooth projective variety over an algebraically closed field of characteristic 0. We prove that the category of μ-semistable reflexive sheaves of slope μ equivariant for the action of some group on X is Abelian. The same claim for and a stronger semistability condition gives us a geometric proof of the fact that the category of mixed Hodge structures is Abelian. To cite this article: O. Penacchio, C. R. Acad. Sci. Paris, Ser. I 335 (2002) 475–480. 相似文献
2.
Summary. The perfectly matched layer (PML) is an efficient tool to simulate propagation phenomena in free space on unbounded domain.
In this paper we consider a new type of absorbing layer for Maxwell's equations and the linearized Euler equations which is
also valid for several classes of first order hyperbolic systems. The definition of this layer appears as a slight modification
of the PML technique. We show that the associated Cauchy problem is well-posed in suitable spaces. This theory is finally
illustrated by some numerical results. It must be underlined that the discretization of this layer leads to a new discretization
of the classical PML formulation.
Received May 5, 2000 / Published online November 15, 2001 相似文献
3.
Philippe Quevauviller Rob Ritsema Roberto Morabito Wilfried M. R. Dirkx Salvatore Chiavarini Jos M. Bayona Olivier F. X. Donard 《应用有机金属化学》1994,8(6):541-549
Biogeochemical pathways of tin species in the environment are still controversial, e.g. with regard to methylation and transmethylation phenomena, owing to the fact that the identification of methylated tin-compounds is often difficult. The previous tentative identification of a mixed methylbutyltin compound in sediment and biological samples by GC/AAS after hydride generation gave an illustration of this problem. This compound was previously identified in sediments by other authors and also suspected to occur in a contaminated sediment sample from the Boyardville Marina, France. The retention time obtained by GC/AAS corresponded to the actual retention time of a mixed methylbutyltin calibrant. However, additional checks demonstrated that the compound detected was actually monophenyltin. This evidence was produced by a thorough analysis of a selected sediment sample by alternative techniques such as GC/AAS and GC/AES after pentylation, GC/FPD and GC/MS. The results presented highlight the need for a full identification of compounds to avoid mis-interpretation. 相似文献
4.
A time‐marching formulation is derived from the space–time integrated least squares (STILS) method for solving a pure hyperbolic convection equation and is numerically compared to various known methods. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
5.
Patrick Pruja Sauveur Bnet Bernard Claudet Olivier Faugeroux Jean-Jacques Serra 《Superlattices and Microstructures》2004,35(3-6):409
Modeling the behavior of a protective coating during a thermal shock not only requires the knowledge of its own thermophysical characteristics, but also those of the coating–substrate discontinuity. According to its nature, this discontinuity can be modeled as a zero-thickness interface (thermal contact resistance) or a finite thickness layer (thermal third body). This paper presents an experimental device and two associated thermal transfer models developed in view of the microscale characterization of such discontinuities. 相似文献
6.
Bassan Bruno Gossner Olivier Scarsini Marco Zamir Shmuel 《International Journal of Game Theory》2003,32(1):17-31
We exhibit a general class of interactive decision situations in which all the agents benefit from more information. This class includes as a special case the classical comparison of statistical experiments à la Blackwell.
AMS 2000 Subject Classification:Primary 91A35.The work of Bruno Bassan and Marco Scarsini was partially supported by MIUR-COFIN. The authors express their thanks to Sylvain Sorin for enlightening comments. 相似文献
7.
L. D. Olivier W. A. Richter J. A. Stander J. W. Koen 《Zeitschrift für Physik A Hadrons and Nuclei》1993,347(2):99-108
Levels up to 9.3 MeV excitation in22Ne were studied with the19 F(α, pγ) 22Ne reaction atE α = 12 MeV. Level energies, branching ratios, mean lifetimes, spins and mixing ratios were obtained for a number of levels. Relevant results are compared with many-particle shell-model calculations. 相似文献
8.
A good agreement has been observed between the proton longitudinal relaxation rate in the two and one layer hydrate of the Na-Llano vermiculite, the location of the Fe3+ paramagnetic centers within the octahedral and tetrahedral layers of the lattice and the electronic longitudinal relaxation rate using the dipolar electronic—proton spin interaction. The water content influences noticeably the electronic longitudinal relaxation time. 相似文献
9.
Boron was analysed in ore and glass samples by prompt proton spectrometry, using deuterons of 2.7 MeV to coincide with a region
where the excitation function of the10B(d, p)11B reaction did not vary appreciably with energy.
Targets of approximately 300 μg/cm2 thick of powdered samples were prepared by centrifugation. Concentrations down to 0.2% were determined. Possible interference
by other elements, particularly nitrogen, magnesium and titanium, was investigated. 相似文献
10.
The synthesis of alkylarylphosphines is easily carried out by hydrophosphination of unactivated alkenes under mild thermal activation; gram scale amounts of products can be prepared by this simple methodology. 相似文献