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91.
Møller’s energy-momentum complex is employed in order to determine the energy and momentum distributions for a spacetime described by a “generalized Schwarzschild” geometry in (3+1)-dimensions on a noncommutative curved D3-brane in an effective, open bosonic string theory. The geometry considered is obtained by an effective theory of gravity coupled with a nonlinear electromagnetic field and depends only on the generalized (effective) mass and charge which incorporate corrections of first order in the noncommutativity parameter. 相似文献
92.
The haploid–diploid cycle where, under unfavorable conditions the population becomes diploid, is modeled by a Monte-Carlo method in the framework of the Jan–Stauffer–Moseley hypothesis. Diploidy and sex may have first arisen as a way to escape death, when a simple unicellular individual is threatened by too many deleterious mutations. Using a bit string model, we find that in a system where competition is present (through the Verhulst factor), diploids dominate. In this case the transition from haploid to essentially diploid population takes place in a short time interval reminiscent of phase transitions in physical systems. 相似文献
93.
We review the theory of inflationary perturbations. Perturbations at both linear and nonlinear orders are reviewed. We also review a variety of inflation models, emphasizing their signatures on cosmic perturbations. 相似文献
94.
Zeta-nonlocal scalar fields 总被引:1,自引:0,他引:1
B. Dragovich 《Theoretical and Mathematical Physics》2008,157(3):1671-1677
We consider some nonlocal and nonpolynomial scalar field models originating from p-adic string theory. An infinite number
of space-time derivatives is determined by the operator-valued Riemann zeta function through the d’Alembertian □ in its argument.
The construction of the corresponding Lagrangians L starts with the exact Lagrangian for the effective field of the p-adic tachyon string, which is generalized by replacing p with an arbitrary natural number
n and then summing over all n. We obtain several basic classical properties of these fields. In particular, we study some solutions of the equations
of motion and their tachyon spectra. The field theory with Riemann zeta-function dynamics is also interesting in itself.
Dedicated to Vasilii Sergeevich Vladimirov on his 85th birthday
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 157, No. 3, pp. 364–372, December, 2008. 相似文献
95.
We study a relativistic quantum particle in cosmic string spacetime in the presence of a magnetic field and a Coulomb-type scalar potential. It is shown that the radial part of this problem possesses the su(1,1) symmetry. We obtain the energy spectrum and eigenfunctions of this problem by using two algebraic methods: the Schrödinger factorization and the tilting transformation. Finally, we give the explicit form of the relativistic coherent states for this problem. 相似文献
96.
Proposed sets of critical exponents for randomly branched polymers,using a known string theory model
N.H. March 《Phase Transitions》2016,89(6):543-546
The critical exponent ν for randomly branched polymers with dimensionality d equal to 3, is known exactly as 1/2. Here, we invoke an already available string theory model to predict the remaining static critical exponents. Utilizing results of Hsu et al. (Comput Phys Commun. 2005;169:114–116), results are added for d = 8. Experiment plus simulation would now be important to confirm, or if necessary to refine, the proposed values. 相似文献
97.
After the nontrivial quantum parameters Ω n and quantum potentials V n obtained in our previous research, the circumstance of a real scalar wave in the bulk is studied with the similar method of Brevik and Simonsen (Gen. Rel. Grav. 33:1839, 2001). The equation of a massless scalar field is solved numerically under the boundary conditions near the inner horizon r e and the outer horizon r c . Unlike the usual wave function Ψωl in 4D, quantum number n introduces a new functions Ψωl n , whose potentials are higher and wider with bigger n. Using the tangent approximation, a full boundary value problem about the Schrödinger-like equation is solved. With a convenient replacement of the 5D continuous potential by square barrier, the reflection and transmission coefficients are obtained. If extra dimension does exist and is visible at the neighborhood of black holes, the unique wave function Ψωl n may say something to it. 相似文献
98.
M. Gonçalves M. Chiapparini L. Castro E.C. de Oliveira S.B. Duarte E.L. Medeiros 《The European Physical Journal A - Hadrons and Nuclei》2000,7(3):435-440
The effect of multiparticle correlations on resonance and pion populations, in relativistic nuclear reactions, is calculated
in the context of an intranuclear cascade model which includes N-body (N > 2) collisional processes. The resonance-matter
population present in the highly-compressed phase of nucleus-nucleus collisions is investigated, in reactions between different
intermediate-mass nuclear systems.
Received: 29 December 1998 / Revised version: 20 December 1999 相似文献
99.
We explore some possible mechanisms by which the heavy neutral cosmic particles are accelerated to gain sufficiently high kinetic energies and cause observable effects at detectors on the earth. Our results indicate that all the known sources which are based on the established theories and observations fail to give rise to very high energy with sizable flux intensity. If the heavy neutral particles of kinetic energies of GeV order indeed exist in cosmic rays, there must be certain mechanisms beyond our present knowledge of dark matter and universe evolution. 相似文献
100.