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231.
A. V. Korshunov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(7):1202-1210
Regularities of the interaction of widely dispersed industrial powders and electroexplosive aluminum nanopowder with nitrogen
under atmospheric pressure in a linearly rising temperature and isothermal conditions have been investigated. The effect of
the powder’s dispersion and composition, and the structure of the oxide shell and metal core of the aluminum particles on
the temperature range of reaction and its kinetic parameters is shown. The relationship between the process of dehydration
of hydroxides that are part of the superficial oxide shell of Al particles and the initial temperature of interaction between
the powders and nitrogen was investigated. It is shown that the staged nature of weight gain for powders in a nitrogen atmosphere
that is observed under conditions of linear heating results from a change in the macrokinetic regime, due to the effect of
the Al nitride layer. 相似文献
232.
It has been found that, in contrast to the commonly accepted opinion, simultaneous irradiation by 15-keV Ar+ ions and 2.5-keV electrons at temperatures above 0.5T m (T m is the melting temperature) induces much larger sputtering of metallic copper, nickel, and steel than irradiation only by Ar+ ions. The effect increases with the temperature. At T = 0.7T m, the sputtering coefficients in the case of ion-electron irradiation are more than twice as large as the sputtering coefficients in the case of irradiation by Ar+ ions. The experiments on the sublimation of copper show that the sublimation rate in the case of the heating of a sample by an electron beam is higher than that in the case of heating in an electric vacuum oven. The revealed effects are explained by the electron-induced excitation of adatoms (atoms stuck over the surface, which appear owing to ion bombardment). Excited adatoms have a smaller binding energy with the surface and are sputtered more easily. 相似文献
233.
L. S. Danelyan S. N. Korshunov A. N. Mansurova V. V. Zatekin V. S. Kulikauskas I. V. Borovitskaya V. V. Paramonova M. M. Lyakhovitskyi 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2014,8(2):216-219
The features of processes occurring on the surface of vanadium and its alloys irradiated using the ILU ion-beam accelerator with Ar+ ions at an energy of 20 and 40 keV up to doses of 5.0 × 1021 m?2 and 1.0 × 1022 m?2 at T irr ≈ 700 K are studied. The effect of the dose and energy of implanted ions on the surface hardness is obtained. The thickness of the hardened layer is more than two orders of magnitude higher than the theoretical and experimental projected range of Ar+ ions at an energy of 20 and 40 keV in vanadium. Structural changes in the surface layers, which are expressed in a change in the intensity of reflections from a number of planes and an increase in the crystal-lattice parameter of the irradiated materials, are also observed. 相似文献
234.
V. N. Korshunov V. A. Safonov L. N. Vykhodtseva 《Russian Journal of Electrochemistry》2008,44(3):255-264
Characteristics of electroreduction of Cr3+ and Cr2+ ions on the dropping mercury (literature data) and indium cathodes are analyzed as a function of pH of the medium. A hypothesis that polymeric hydroxocompounds of chromium, which are present in different aggregate states, represent the main or partial reactants in the $ Cr\left( {III} \right)\xrightarrow{{ + e}}Cr\left( {II} \right)\xrightarrow{{ + 2e}}Cr Characteristics of electroreduction of Cr3+ and Cr2+ ions on the dropping mercury (literature data) and indium cathodes are analyzed as a function of pH of the medium. A hypothesis
that polymeric hydroxocompounds of chromium, which are present in different aggregate states, represent the main or partial
reactants in the
stages is additionally substantiated.
Original Russian Text ? V.N. Korshunov, V.A. Safonov, L.N. Vykhodtseva, 2008, published in Elektrokhimiya, 2008, Vol. 44,
No. 3, pp. 275–285. 相似文献
235.
D. A. Korshunov 《Siberian Mathematical Journal》2009,50(4):663-666
We deduce an analog of the classical Wald’s identity ES τ = EτEξ in the case of the infinite mean of summands. We find the conditions on τ under which Emin(S τ , x) ~ EτE min(ξ, x) as x→∞. 相似文献
236.
The effective Hamiltonian for a realistic multiband p-d model is developed. In the case of electron doping, the Hamiltonian coincides with that for the standard t-J model. For hole doping, the singlet-triplet t-J model takes place. 相似文献
237.
A. S. Antsyshkina G. G. Sadikov A. I. Uraev O. Yu. Korshunov A. L. Nivorozhkin A. D. Garnovskii 《Crystallography Reports》2000,45(5):778-781
Three compounds of the pyrazole series—o-oxo, thio, and seleno derivatives—have been synthesized and characterized by IR and NMR spectroscopy. The crystal structure of the oxo derivative is determined (Syntex P21 diffractometer, MoK α radiation, graphite monochromator, θ/2θ scan mode, 2θmax = 57°, direct method, anisotropic—isotropic (H) least-squares refinement for 2015 reflections, R = 0.043, wR2 = 0.1084). The crystals are monoclinic, a = 7.543(1) Å, b = 7.850(2) Å, c = 27.909(6) Å, β = 93.79(3)°, Z = 2, and space group P21/c. It is found that the o-hydroxyazomethine derivatives of the pyrazolone series exist in the crystal as 4-aminomethylene-5-oxo tautomers. The proton is localized at the exocyclic N atom. It lies in the plane of the main molecular fragment and participates in the intramolecular bifurcate N—H?O(N) hydrogen bond, which closes the six-membered and five-membered H-rings, respectively. 相似文献
238.
An original experimental method is developed for determining the sputtering coefficients of electrically conducting materials
during bombardment by light gas ions at threshold energies. This information is very valuable in both purely scientific and
practical terms. The basis of the method is a special field-ion-microscopic analysis regime. The procedure for measuring the
sputtering coefficients includes cleaning the surface by field desorption and evaporation, with the subsequent work on an
atomically clean and atomically smooth surface. The method permits identification of single vacancies on the irradiated surface,
i.e., it is possible to count individual sputtered atoms. The method is tested on commercially pure tungsten, tungsten oxide,
and a W-C mixed layer on tungsten under deuterium ion bombardment. The energy dependences of the sputtering coefficients of
these materials for sputtering by deuterium ions at energies of 10–500 eV are obtained and analyzed. An important relationship
between the energy threshold for sputtering and the conditions for oxidation of tungsten is found. The energy threshold for
sputtering of an oxidized tungsten surface is 65 eV. The energy threshold for sputtering of the W-C mixed layer is almost
equal to the corresponding value for pure tungsten.
Zh. Tekh. Fiz. 69, 137–142 (September 1999) 相似文献
239.
We report a generalization of our earlier formalism [Pramana, 54, 663 (1998)] to obtain exact solutions of Einstein-Maxwell’s equations for static spheres filled with a charged fluid having
anisotropic pressure and of null conductivity. Defining new variables: w=(4π/3)(ρ+ε)r
2, u=4πξr
2, v
r=4πp
r
r
2, v
⊥=4πp
⊥
r
2[ρ, ξ(=−(1/2)F
14
F
14), p
r, p
⊥ being respectively the energy densities of matter and electrostatic fields, radial and transverse fluid pressures whereas
ε denotes the eigenvalue of the conformal Weyl tensor and interpreted as the energy density of the free gravitational field],
we have recast Einstein’s field equations into a form easy to integrate. Since the system is underdetermined we make the following
assumptions to solve the field equations (i) u=v
r=(a
2/2κ)r
n+2, v
⊥=k
1
v
r, w=k
2
v
r; a
2, n(>0), k
1, k
2 being constants with κ=((k
1+2)/3+k
2) and (ii) w+u=(b
2/2)r
n+2, u=v
r, v
⊥−v
r=k, with b and k as constants. In both cases the field equations are integrated completely. The first solution is regular in the metric as
well as physical variables for all values of n>0. Even though the second solution contains terms like k/r
2 since Q(0)=0 it is argued that the pressure anisotropy, caused by the electric flux near the centre, can be made to vanish reducing
it to the generalized Cooperstock-de la Cruz solution given in [14]. The interior solutions are shown to match with the exterior
Reissner-Nordstrom solution over a fixed boundary.
Dedicated to Prof. F A E Pirani. 相似文献
240.
The problem considered is the fitting of a many-body interaction potential to bulk crystal data. A parameterisation of the
potential is assumed which is based on physical considerations. The free parameters are determined by using global optimization
to perform a least squares fit, to a large number of crystal properties. This has been achieved for body centered cubic (bcc)
materials. The approach adopted here fits the bcc crystal structure, as the preferred minimum energy configuration for tungsten,
and also fits the dimer energetics and the elastic properties of crystalline tungsten. 相似文献