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31.
Edward K. G. Sarkisyan Alexander S. Sakharov 《The European Physical Journal C - Particles and Fields》2010,70(3):533-541
The energy-dependence of charged particle mean multiplicity and pseudorapidity density at midrapidity measured in nucleus–nucleus
and (anti)proton–proton collisions are studied in the entire available energy range. The study is performed using a model,
which considers the multiparticle production process according to the dissipating energy of the participants and their types,
namely a combination of the constituent quark picture together with Landau relativistic hydrodynamics. The model reveals interrelations
between the variables under study measured in nucleus–nucleus and nucleon–nucleon collisions. Measurements in nuclear reactions
are shown to be well reproduced by the measurements in pp/[`(p)]p{\bar{\mathrm{p}}}{\mathrm{p}} interactions and the corresponding fits are presented. Different observations in other types of collisions are discussed
in the framework of the proposed model. Predictions are made for measurements at the forthcoming LHC energies. 相似文献
32.
33.
Alexey V. Smirnov Levan S. Kalandadze Vladimir N. Sakharov Mikhail V. Dorogov Alexander V. Ivachtchenko 《Journal of heterocyclic chemistry》2007,44(6):1247-1251
34.
T. L. Makarova V. I. Sakharov I. T. Serenkov A. Ya. Vul’ 《Physics of the Solid State》1999,41(3):497-500
The composition and structure of C60 fullerite films prepared by discrete evaporation in quasiclosed volume, as well as their changes induced by laser irradiation, have been studied by ellipsometry and Rutherford backscattering. The starting film has a 150-Å thick stable top layer and a carbon to oxygen ratio of 10:1. Exposure of a film both to vacuum and to air results in formation of an insoluble photo-transformed phase, but in the second case the change in the refractive index implies the appearance of compounds with oxygen. The material does not undergo complete polymerization, although all structural changes cease at an irradiation dose of 104 photons per fullerene molecule. Treatment of the polymerized phase with organic solvents produces a porous structure, with the voids totaling 48% in the case of exposure in vacuum, and 30% when exposed in air. 相似文献
35.
V. V. Afrosimov R. N. Il’in V. I. Sakharov I. T. Serenkov D. V. Yanovskii S. F. Karmanenko A. A. Semenov 《Physics of the Solid State》1999,41(4):527-533
The initial stages in the formation and growth of yttrium-barium cuprate films have been studied in the course of magnetron
sputtering of a ceramic target by combining medium-energy-ion scattering (MEIS) and scanning-electron microscopy. The growth
mechanisms of YBa2Cu3O7−x
films on MgO and substrates having the perovskite structure, SrTiO3 and LaAlO3, at deposition temperatures of 700–780 °C and (Ar+O2) pressure of ∼70 Pa were found to be essentially different. Simulation of MEIS spectra (H+ or He+ ions with initial energies of 150–250 keV) and comparison of these results with experimental data revealed that in the first
case a film forms from pyramid-shaped islands and, in the second, it grows by a two-dimensional layer-by-layer process starting
practically with the first monolayer. For the island mechanism, MEIS permitted determination of the substrate surface coverage
and showed the growth of the YBa2Cu3O7−x
phase to be paralleled by formation of epitaxial nuclei of a Cu2O phase. After the first, initial stage in the film formation, the second stage, regular growth within reduced thicknesses
of 7–15 nm, sets in. This stage is characterized by a practically complete coverage of the substrate and a stable composition.
The third stage, regular growth, of an apparently helical nature, was observed to set in at thicknesses above 100 nm. In this
stage, the quality of film structure in the bulk and on the surface was found to be somewhat inferior to that of YBa2Cu3O7−x
single crystals and did not depend on substrate type.
Fiz. Tverd. Tela (St. Petersburg) 41, 588–595 (April 1999) 相似文献
36.
S. G. Sakharov N. I. Pakuro A. A. Arest-Yakubovich L. V. Shcheglova P. V. Petrovskii 《Journal of organometallic chemistry》1999,580(2):2283
Mixtures of 2-ethylhexylsodium and 2-ethylhexyllithium are studied by 1H- and 13C-NMR spectroscopy in the temperature range from 20 to −50°C in hydrocarbon solutions. Characteristic temperature-dependent spectra obtained are indicative of dynamic exchange processes taking place in the system. The following activation parameters are found: ΔH≠=31.7±2.7 kJ mol−1; ΔG≠313=58.7±0.6 kJ mol−1; ΔS≠=−86.37±10.8 J mol−1 K−1. The negative value of the activation entropy indicates that the exchange proceeds through the associative mechanism. The participation in exchange reactions of aggregates, containing both sodium and lithium derivatives, is suggested. 相似文献
37.
N. A. Barkhatov N. S. Bellustin A. E. Levitin S. Y. Sakharov 《Radiophysics and Quantum Electronics》2000,43(5):347-355
Using artificial neural networks (ANN), we study problems of forecasting the evolution of the geomagnetic D
st
index on the basis of parameters of the solar-wind plasma and magnetic field obtained from the OMNI satellite system. Using
this sample problem, we compare the neural network modifications with error backpropagation, such as classic network and feedback
network. We analyze the efficiency of a feedback in the hidden layer of the Elman neural network which has a dynamic memory
due to the time delay. The role of a delay in the input layer of a neural network is studied. It is shown that the forecasting
efficiency increases significantly if a feedback in the hidden layer and the time delay in the input layer are used. The hidden-layer
feedback and the input-layer time delay reproduce the time delay in the physical problem considered. Using thresholds in activation
functions does not influence the ANN efficiency. The solar-wind parameters that have the strongest influence on the geomagnetic-storm
formation are found. The influence of the number of hidden-layer neurons on the quality of forecasting the global disturbances
in the near-Earth magnetic field is studied. It is pointed out that the networks with error backpropagation allow, after the
relevant tuning and learning, fairly efficient forecasting of phenomena similar to geomagnetic storms several hours before
a large-scale magnetospheric event.
Pedagogical University, Nizhny Novgorod, Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol.
43, No. 5, pp. 385–394, May, 2000. 相似文献
38.
Sakharov V. K. Khivintsev Y. V. Dudko G. M. Vysotskii S. L. Filimonov Y. A. 《Physics of the Solid State》2019,61(9):1602-1608
Physics of the Solid State - In this paper, we study the features of the spin-wave excitation spectrum in a YIG film with a thickness of 0.4 μm and a magnetization of 1.1 kG corrugated due to... 相似文献
39.
Sredin V. G. Voitsekhovskii A. V. Sakharov M. V. Talipov N. Kh. 《Russian Physics Journal》2019,62(6):1062-1065
Russian Physics Journal - The paper considers the effect of elastic stresses arising under pulsed laser irradiation of epitaxial layers of CdxHg1–xTe solid solutions on the formation of a... 相似文献
40.
G. S. Kurskiev N. V. Sakharov P. B. Schegolev N. N. Bakharev E. O. Kiselev G. F. Avdeeva V. K. Gusev A. D. Iblyaminova V. B. Minaev I. V. Miroshnikov M. I. Patrov Yu. V. Petrov A. Yu. Telnova S. Yu. Tolstyakov V. A. Tokarev 《Physics of Atomic Nuclei》2017,80(7):1313-1319
Experimental study of thermal energy confinement in magnetic confinement devices is one of the fundamental problems in plasma physics. The data processing technique covering kinetic and magnetic measurements performed for the Globus-M tokamak is described. A zero-dimensional code has been developed on the basis of this approach making it possible to calculate important discharge parameters during the experiment (between discharges): the electron and ion stored thermal energy content, plasma effective charge, and confinement time. Good agreement of the zero-dimensional calculations and ASTRA modeling indicates that this approach can be applied for routine data processing in Globus-M in view of the specifics of the device. 相似文献