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31.
The anion-exchange properties of a new organomineral sorbent obtained by modification of clinoptilolite-containing tuffs by polyhexamethyleneguanidine have been studied after different periods of storage (time after synthesis) and numbers of sorption-regeneration cycles. The sorbent can be used as a cation- and an anion-exchanger simultaneously. Selectivity coefficients (exchange constants) for F–, SO4
2–, and HPO4
2– ionsvs. Cl– ions on modified clinoptilolite-containing tuffs have been determined. The modification improves the mechanical properties of clinoptilolite tuffs.For part 1, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1554–1556, September, 1994. 相似文献
32.
33.
A vector field q (the order parameter of the molecular packing) describing the packing (specifically, the orientation) of membrane-forming
amphiphilic molecules is introduced to describe the structures of lyotropic phases constructed from membranes. In the general
case q·n≠0 (where n is the unit normal vector) and therefore the singularities of the vector field q are not determined uniquely by the topology of the surface. The condition q·n=0 signifies disruption of the packing of the molecules. This corresponds to holes, which can form in membranes when lyotropic
systems are diluted. As an illustration, the simplest type of such singularities, in which the distribution of the field q around a hole is described by a part of an instanton with unit topological charge, is studied. It is shown that such a distribution
guarantees the existence of a local minimum under the condition that the tension per unit length λ of the hole boundary is small compared with the deformation energy of the field q:
λh/K≪l (K is the modulus of the orientational elasticity of the field q and h is the thickness of the membrane). The radius of the hole which is formed equals L≈2.52(K/λh)1/3 and the energy E≈59.79K(λh/K)1/3.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 8, 575–580 (25 October 1996) 相似文献
34.
Summary We show that in theA-phase of superfluid3He one may expect the Mandelstam-Brillouin light scattering from spin waves. The scattering is caused by fluctuations of the
magnetic susceptibility.
Riassunto Si mostra che nella faseA del superfluido3He ci si può aspettare diffusione di luce di Mandelstam-Brillouin da onde di spin. La diffusione è caratterizzata da fluttuazioni della suscettibilità magnetica.
Резюме Мы покаем, что ьА-qfазе сьерхтекучего3He μожно ожидать рассеяние света Мандельштама-Бриллюэна на спиновых волнах. Рассеяние обусповлено флуктациями магнитной восприимчивости.相似文献
35.
I. S. Kats 《Ukrainian Mathematical Journal》1994,46(3):159-182
In this survey, we present the principal results of Krein's spectral theory of a string and describe its development by other authors.Translated from Ukrainskii Matematicheskii Zhurnal, Vol. 46, No. 3, pp. 155–176, March, 1994. 相似文献
36.
A number of methods have been proposed in recent years for calculating the combined flows of immiscible and miscible liquids in strata to systems of boreholes. We propose a method which can naturally be called the zonal linearization method [1]. It is more compact than the usual finite-difference method and has high accuracy, in particular, in the neighborhood of a borehole, since it is closely similar to the method of characteristics. The method can be applied to both continuous and discontinuous flows and in principle makes it possible to investigate the formation and breakdown of discontinuities. As distinct from the method of characteristics, it is well suited to programming and implementation on a computer, and it also makes it possible to obtain an approximate analytic solution of the problem in many cases and to estimate the accuracy of the solution. The method is based on the zonal linearization of the equation for mass conservation in the total flow between chosen surfaces or contour lines (lines of equal saturation or concentration). Determination of the dynamics of the contour surfaces leads to a Cauchy problem for a system of integrodifferential equations involving partial derivatives. The zonal linearization method is a development of the scheme described in [2–4], and the method of solving the Cauchy problem is a generalization of the methods described in [4–13]. The essence of the method and its convergence are illustrated by means of two-dimensional problems in two-phase filtration.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 4, pp. 66–80, July–August, 1973. 相似文献
37.
The broad-band normal incidence UVB beam radiation has been measured at Neve Zohar, Dead Sea basin, using a prototype tracking instrument composed of a Model 501A UV-Biometer mounted on an Eppley Solar Tracker Model St-1. The diffuse and beam fraction of the solar global UVB radiation have been determined using the concurrently measured solar global UVB radiation. The diffuse fraction was observed to exceed 80% throughout the year. The application of the results of these measurements to the possible revision of the photoclimatherapy protocol for psoriasis patients at the Dead Sea medical spas is now under investigation. The suggested revision would enable the sun-exposure treatment protocol to take advantage of the very high diffuse fraction by allowing the patient to receive the daily dose of UVB radiation without direct exposure to the sun, viz. receive the diffuse UVB radiation under a sunshade. This would require an increase in sun-exposure time intervals, as the UVB radiation intensity beneath a sunshade is less than that on an exposed surface. 相似文献
38.
Efim Pelinovsky Tatiana Talipova Ira Didenkulova Ekaterina Didenkulova 《Studies in Applied Mathematics》2019,142(4):513-527
Long wave propagation in a two‐layer fluid with variable depth is studied for specific bottom configurations, which allow waves to propagate over large distances. Such configurations are found within the linear shallow‐water theory and determined by a family of solutions of the second‐order ordinary differential equation (ODE) with three arbitrary constants. These solutions can be used to approximate the true bottom bathymetry. All such solutions represent smooth bottom profiles between two different singular points. The first singular point corresponds to the point where the two‐layer flow transforms into a uniform one. In the vicinity of this point nonlinear shallow‐water theory is used and the wave breaking criterion, which corresponds to the gradient catastrophe is found. The second bifurcation point corresponds to an infinite increase in water depth, which contradicts the shallow‐water assumption. This point is eliminated by matching the “nonreflecting” bottom profile with a flat bottom. The wave transformation at the matching point is described by the second‐order Fredholm equation and its approximated solution is then obtained. The results extend the theory of internal waves in inhomogeneous stratified fluids actively developed by Prof. Roger Grimshaw, to the new solutions types. 相似文献
39.
A class of essentially non-equilibrium distributions characterized by the constant flux of one of the “integral of motion” (e.g. energy, number of particles or momentum) both for waves and particles is shown to exist in plasmas due to the symmetry of collision integrals (particle-wave interactions or Boltzmann's integral resp.). As a result, the non-equilibrium distributions can be obtained from a functional equation inferring that the projection of the stoss-integrand on the irreducible group representation should be equal to zero. 相似文献
40.