全文获取类型
收费全文 | 1398篇 |
免费 | 36篇 |
国内免费 | 1篇 |
专业分类
化学 | 689篇 |
晶体学 | 19篇 |
力学 | 41篇 |
数学 | 125篇 |
物理学 | 561篇 |
出版年
2021年 | 9篇 |
2020年 | 23篇 |
2019年 | 14篇 |
2016年 | 30篇 |
2015年 | 23篇 |
2014年 | 38篇 |
2013年 | 54篇 |
2012年 | 66篇 |
2011年 | 54篇 |
2010年 | 38篇 |
2009年 | 40篇 |
2008年 | 50篇 |
2007年 | 36篇 |
2006年 | 37篇 |
2005年 | 30篇 |
2004年 | 38篇 |
2003年 | 30篇 |
2002年 | 29篇 |
2001年 | 48篇 |
2000年 | 38篇 |
1999年 | 30篇 |
1998年 | 15篇 |
1997年 | 22篇 |
1996年 | 34篇 |
1995年 | 13篇 |
1994年 | 19篇 |
1993年 | 28篇 |
1992年 | 15篇 |
1991年 | 26篇 |
1990年 | 9篇 |
1989年 | 31篇 |
1988年 | 22篇 |
1987年 | 20篇 |
1986年 | 23篇 |
1985年 | 20篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 23篇 |
1981年 | 23篇 |
1980年 | 14篇 |
1979年 | 18篇 |
1978年 | 22篇 |
1977年 | 22篇 |
1976年 | 19篇 |
1975年 | 9篇 |
1974年 | 17篇 |
1973年 | 13篇 |
1972年 | 10篇 |
1971年 | 13篇 |
1970年 | 12篇 |
排序方式: 共有1435条查询结果,搜索用时 15 毫秒
91.
Yaschenko S Dymov S Kacharava A Komarov V Macharashvili G Rathmann F Barsov S Gebel R Hartmann M Khoukaz A Kulessa P Kulikov A Kurbatov V Lang N Lehmann I Lorentz B Mersmann T Merzliakov S Mikirtytchiants S Mussgiller A Nioradze M Ohm H Prasuhn D Schleichert R Seyfarth H Steffens E Stein HJ Ströher H Uzikov Y Zalikhanov B Zhuravlev N 《Physical review letters》2005,94(7):072304
A measurement of the analyzing power A(y) of the p-->d--> (p p) + n reaction was carried out at the ANKE spectrometer at COSY at beam energies of 0.5 and 0.8 GeV by detection of a fast forward proton pair of small excitation energy E(pp) < 3 MeV. The S-wave dominance in the fast diproton is experimentally demonstrated in this reaction. While at T(p) = 0.8 GeV the measured analyzing power almost vanishes, it rises to nearly unity at T(p) = 0.5 GeV for neutrons emitted at theta(c.m.)(n) = 167 degrees. The results are compared with a model taking into account one-nucleon exchange, single scattering, and Delta(1232) excitation in the intermediate state. The model describes fairly well the unpolarized cross section obtained earlier and the analyzing power at 0.8 GeV; it fails to reproduce A(y) at 0.5 GeV. 相似文献
92.
Reisdorf W Andronic A Gobbi A Hartmann ON Herrmann N Hildenbrand KD Kim YJ Kirejczyk M Koczoń P Kress T Leifels Y Schüttauf A Tymiński Z Xiao ZG Alard JP Barret V Basrak Z Bastid N Benabderrahmane ML Caplar R Crochet P Dupieux P Dzelalija M Fodor Z Grishkin Y Hong B Kecskemeti J Korolija M Kotte R Lebedev A Lopez X Merschmeyer M Mösner J Neubert W Pelte D Petrovici M Rami F de Schauenburg B Seres Z Sikora B Sim KS Simion V Siwek-Wilczyńska K Smolyankin V Stockmeier M Stoicea G Wagner P 《Physical review letters》2004,92(23):232301
We present a complete systematics (excitation functions and system-size dependences) of global stopping and side flow for heavy ion reactions in the energy range between 0.09A and 1.93A GeV. For the heaviest system, Au+Au, we observe a plateau of maximal stopping extending from about 0.2A to 0.8A GeV with a fast drop on both sides. The degree of stopping, which is shown to remain significantly below the expectations of a full stopping scenario, is found to be highly correlated to the amount of side flow. 相似文献
93.
Hartmann T Babilon M Kamerdzhiev S Litvinova E Savran D Volz S Zilges A 《Physical review letters》2004,93(19):192501
The electric dipole strength distribution in 44Ca has been measured up to 10 MeV in high resolution photon scattering experiments for the first time. The data obtained have been compared to earlier measurements on (40,48)Ca in order to view the evolution of the electric pygmy dipole resonance (PDR). Calculations that were performed within the framework of the microscopic extended theory of finite Fermi systems, which adds contributions of the quasiparticle-phonon coupling to random phase approximation calculations, give a qualitative agreement with the experimental data for all three isotopes. We have shown that it is necessary to include this coupling to describe the PDR. 相似文献
94.
Because of dispersion in head-related transfer functions (HRTFs), the interaural time difference (ITD) varies with frequency. This physical effect ought to have consequences for the size or shape of the auditory image of broadband noise because different frequency regions of the noise have different ITDs. However, virtual reality experiments suggest that human listeners are insensitive to head-related dispersion. The experiments of this article test that suggestion by experiments that isolate dispersion from amplitude effects in the HRTF and attempt to optimize the opportunity for detecting it. Nevertheless, the experiments find that the only effect of dispersion is to shift the lateralization of the auditory image. This negative result is explained in terms of the cross-correlation function for head-dispersed noise. Although the broad-band cross-correlation function differs considerably from 1.0, the cross-correlation functions within bands characteristic of auditory filters do not. A detailed study of the lateralization shifts show that the experimental shifts can be successfully calculated as an average of stimulus ITDs as weighted by Raatgever's frequency-weighting function (Thesis, Delft, The Netherlands, 1980). 相似文献
95.
Garçon S Vassiliou S Cavicchioli M Hartmann B Monteiro N Balme G 《The Journal of organic chemistry》2001,66(11):4069-4073
96.
The adsorption of various amino acids on zeolites with different structures was studied with regard to dependence of the pH value of the solution and the aluminum content of the zeolite in order to design tailor-made adsorbents for amino acid separations. 相似文献
97.
Kremer F Hartmann L Serghei A Pouret P Léger L 《The European physical journal. E, Soft matter》2003,12(1):139-142
Broadband Dielectric Spectroscopy is employed to study the molecular dynamics in thin layers of grafted and spin-coated polydimethylsiloxane (PDMS) and of the type-A polymer cis-1,4-polyisoprene (PI). Strong resemblance with low-molecular-weight systems is found but additionally the conformation of the chain and its extension becomes important. For PI a confinement-induced relaxation is found. It is observable if the layer thickness is comparable to the end-to-end vector of the chain and it depends strongly on the separation between interfaces. In contrast, the dynamic (and hence the calorimetric) glass transition is not affected by the geometrical confinement.Received: 1 January 2003, Published online: 8 October 2003PACS:
64.70.Pf Glass transitions - 83.10.Mj Molecular dynamics, Brownian dynamics - 68.60.-p Physical properties of thin films, nonelectronic 相似文献
98.
M.?MichelEmail author M.?Hartmann J.?Gemmer G.?Mahler 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,34(3):325-330
Within the Lindblad formalism we consider an interacting spin chain coupled locally to heat baths. We investigate the dependence of the energy transport on the type of interaction in the system as well as on the overall interaction strength. For a large class of couplings we find a normal heat conduction and confirm Fourier's Law. In a fully quantum mechanical approach linear transport behavior appears to be generic even for small quantum systems.Received: 14 May 2003, Published online: 11 August 2003PACS:
05.60.Gg Quantum transport -
05.30.-d Quantum statistical mechanics -
05.70.Ln Nonequilibrium and irreversible thermodynamics 相似文献
99.
J. Hartmann 《Transformation Groups》2001,6(2):157-164
Let :GGl(n,
) be a representation of a finite groupG over a field
such that the ring of invariants
is a polynomial algebra
. It is known that in the nonmodular case (i.e., when the order of the group is not divisible by the characteristic of
), the invariants ofG acting on the tensor product
of a polynomial and an exterior algebra are given by
,d denoting the exterior derivative. We show that in the modular case, the ring of invariants in
is of this form if and only if
is a polynomial algebra and all pseudoreflections in (G) are diagonalizable. 相似文献
100.
Unbiased samples of ground states were generated for the short-range Ising spin glass with J(ij) = +/-1, in three dimensions. Clustering the ground states revealed their hierarchical structure, which is explained by correlated spin domains, serving as cores for macroscopic zero energy "excitations." 相似文献