全文获取类型
收费全文 | 510篇 |
免费 | 8篇 |
国内免费 | 4篇 |
专业分类
化学 | 162篇 |
晶体学 | 2篇 |
力学 | 10篇 |
数学 | 205篇 |
物理学 | 143篇 |
出版年
2022年 | 6篇 |
2021年 | 8篇 |
2020年 | 3篇 |
2019年 | 7篇 |
2018年 | 10篇 |
2017年 | 14篇 |
2016年 | 29篇 |
2015年 | 15篇 |
2014年 | 22篇 |
2013年 | 28篇 |
2012年 | 34篇 |
2011年 | 23篇 |
2010年 | 26篇 |
2009年 | 16篇 |
2008年 | 30篇 |
2007年 | 23篇 |
2006年 | 27篇 |
2005年 | 15篇 |
2004年 | 18篇 |
2003年 | 16篇 |
2002年 | 19篇 |
2001年 | 11篇 |
2000年 | 15篇 |
1999年 | 11篇 |
1998年 | 14篇 |
1997年 | 3篇 |
1996年 | 9篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1981年 | 2篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1976年 | 2篇 |
1973年 | 2篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1937年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有522条查询结果,搜索用时 218 毫秒
141.
G. M. Zinovjev S. V. Molodtsov A. N. Sissakian A. S. Sorin 《Physics of Particles and Nuclei Letters》2008,5(1):7-12
The paper is focused on calculating the finite temperature and quark/baryon chemical potential dependencies of the quark condensate and the π-and σ-meson masses in the subcritical region in the instanton model of the QCD vacuum. The impact of phononlike excitation of instanton liquid on the characteristics of the σ meson in such an environment is also examined. 相似文献
142.
We study the natural almost CR structure on the total space of a subbundle of hyperquadrics of the tangent bundle T(M) over a semi-Riemannian manifold (M, g) and show that if the Reeb vector ξ of an almost contact Riemannian manifold is a CR map then the natural almost CR structure on M is strictly pseudoconvex and a posteriori ξ is pseudohermitian. If in addition ξ is geodesic then it is a harmonic vector field. As an other application, we study pseudoharmonic vector fields on a compact strictly pseudoconvex CR manifold M, i.e. unit (with respect to the Webster metric associated with a fixed contact form on M) vector fields X ε H(M) whose horizontal lift X↑ to the canonical circle bundle S1 → C(M) → M is a critical point of the Dirichlet energy functional associated to the Fefferman metric (a Lorentz metric on C(M)). We show that the Euler–Lagrange equations satisfied by X↑ project on a nonlinear system of subelliptic PDEs on M.
Mathematics Subject Classifications (2000): 53C50, 53C25, 32V20 相似文献
143.
C. Beşliu A. Jipa D. Argintaru C. Argintaru R. Zaharia J. Gabriel Rican M. Iosif 《The European Physical Journal A - Hadrons and Nuclei》1998,1(1):65-75
The problem of the nuclear matter jets in nucleus-nucleus collisions at 4.5 A GeV/c is discussed. The global analysis of
experimental data, namely the sphericity tensor, is used to evidence such jets. The experimental results are compared with
those obtained in the same collisions for hydrodynamic flow and thrust. The experiments have been performed in the frame of
the SKM 200 Collaboration from JINR Dubna.
Received: 20 March 1997 / Revised version: 20 July 1997 相似文献
144.
Dominique Grevey Pierre Sallamand Eugen Cicala Sorin Ignat 《Optics & Laser Technology》2005,37(8):647-651
Many laser processes, such as welding or surface treatments are associated with an undesired phenomenon, which is oxidation. The solution commonly employed to solve this problem approaches the shielding gas and/or the shielding gas device. What we propose in this paper is a methodology with the goal to optimize the protection gas device design as well as the gas flow in the case of laser welding and surface treatments. The pressure created by the gas flow on the sample surface is recorded and analysed together with the operating parameters influence in order to reach the objectives. The nozzle system designed and presented below assures the protection against material oxidation using minimal gas flow rates and increases the welding penetration in the case of high-power Nd:YAG laser welding. 相似文献
145.
Sorin Popa 《Inventiones Mathematicae》1995,120(1):427-445
Summary We consider certain conditions for abstract lattices of commuting squares, that we prove are necessary and sufficient for them to arise as lattices of higher relative commutants of a subfactor. We call such lattices standard and use this axiomatization to prove that their sublattices are standard too. We consider a method for producing sublatties and deduce from this and [Po5]| some criteria for bipartite graphs to be graphs of subfactors.Oblatum 25-XI-1994Supported in part by NSF Grant DMS-9206984 相似文献
146.
A. I. Malakhov A. N. Sissakian A. S. Sorin S. Vokal 《Physics of Particles and Nuclei》2007,38(4):407-446
The basic stages of the development of the Veksler and Baldin Laboratory of High Energies, Joint Institute for Nuclear Research, in Dubna are described briefly. Some experiments on the investigation of cumulative particle production and the new direction of investigation of the processes of hadron-nuclear and nuclear-nuclear interaction in which the quark structure of nuclei can be manifested—relativistic nuclear physics—are considered. Basic methodical and experimental results obtained at the synchrophasotron and Nuclotron are presented, ideas produced in collaboration with theoreticians of the Bogoliubov Laboratory of Theoretical Physics are discussed. An overview of investigations in the field of relativistic nuclear physics planned at the Nuclotron is given. 相似文献
147.
148.
Snyder S Solomon J Song XF Sorin V Sosebee M Sotnikova N Souza M Stanton NR Steinbruck G Stephens RW Stevenson ML Stichelbaut F Stoker D Stolin V Stoyanova DA Strauss M Streets K Strovink M Stutte L Sznajder A Tarazi J Tartaglia M Thomas TL Thompson J Toback D Trippe TG 《Physical review letters》2000,84(13):2786-2791
We report a new measurement of the cross section for the production of isolated photons with transverse energies ( E(gamma)(T)) above 10 GeV and pseudorapidities |eta|<2.5 in p&pmacr; collisions at sqrt[s] = 1.8 TeV. The results are based on a data sample of 107.6 pb(-1) recorded during 1992-1995 with the D0 detector at the Fermilab Tevatron collider. The background, predominantly from jets which fragment to neutral mesons, was estimated using the longitudinal shower shape of photon candidates in the calorimeter. The measured cross section is in good agreement with the next-to-leading order QCD calculation for E(gamma)(T) greater, similar36 GeV. 相似文献
149.
In this paper we first develop a theory of almost automorphic
functions with values in Frechet spaces. Then, we consider the
semilinear differential equation x'(t) = A x(t) + f(t, x(t)), t ∈ ℝ in a Frechet space X, where A is the infinitesimal generator
of a C0-semigroup satisfying some conditions of exponential stability. Under suitable conditions on f, we prove the existence and
uniqueness of an almost automorphic mild solution to the equation. 相似文献
150.
Sorin Marculescu 《Nuclear Physics B》1983,213(3):523-544
A method for regularizing the supercurrent, preserving both gauge invariance and supersymmetry is developed, using point-splitting regularization and path-dependent phase factors in superspace. The supercurrent anomaly for general non-abelian supersymmetric theories is obtained on the mass-shell in the one-loop approximation. 相似文献