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941.
We consider the class of quadratically-constrained quadratic-programming methods in the framework extended from optimization
to more general variational problems. Previously, in the optimization case, Anitescu (SIAM J. Optim. 12, 949–978, 2002) showed superlinear convergence of the primal sequence under the Mangasarian-Fromovitz constraint qualification and the quadratic
growth condition. Quadratic convergence of the primal-dual sequence was established by Fukushima, Luo and Tseng (SIAM J. Optim.
13, 1098–1119, 2003) under the assumption of convexity, the Slater constraint qualification, and a strong second-order sufficient condition.
We obtain a new local convergence result, which complements the above (it is neither stronger nor weaker): we prove primal-dual
quadratic convergence under the linear independence constraint qualification, strict complementarity, and a second-order sufficiency
condition. Additionally, our results apply to variational problems beyond the optimization case. Finally, we provide a necessary
and sufficient condition for superlinear convergence of the primal sequence under a Dennis-Moré type condition.
Research of the second author is partially supported by CNPq Grants 300734/95-6 and 471780/2003-0, by PRONEX–Optimization,
and by FAPERJ. 相似文献
942.
In this paper the continuous utility representation problem will be discussed in arbitrary concrete categories. In particular,
generalizations of the utility representation theorems of Eilenberg, Debreu and Estévez and Hervés will be presented that
also hold if the codomain of a utility function is an arbitrary totally ordered set and not just the real line. In addition,
we shall prove and apply a general result on the characterization of structures that have the property that every continuous
total preorder has a continuous utility representation. Finally, generalizations of the utility representation theorems of
Debreu and Eilenberg will be discussed that are valid if we consider arbitrary binary relations and allow a utility function
to have values in an arbitrary totally ordered set.
相似文献
943.
The present study investigates the effects of heat and mass transfer on peristaltic transport in a porous space with compliant walls. The fluid is electrically conducting in the presence of a uniform magnetic field. Analytic solution is carried out under long-wavelength and low-Reynolds number approximations. The expressions for stream function, temperature, concentration and heat transfer coefficient are obtained. Numerical results are graphically discussed for various values of physical parameters of interest. 相似文献
944.
The near-IR spectroscopy method of control of the octane number (o.n.) of a fuel is studied. An analysis is made of a device
developed as an alternative of a measuring system based on a nonselective IR radiation source and of an analyzer based on
a laser semiconductor diode. It is shown that the use of the methods of multicomponent regression analysis of spectral data
allows measurement of the octane number with an accuracy of S ∼ 0.17 octane number units. The characteristics of the semiconductor
laser-based analyzer are investigated and the parameters of radiators are discussed that provide the required sensitivity
of the measuring system (up to 10−4 with respect to optical absorption) in controlling the octane number of a fucl.
Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 2, pp. 244–248, March–April, 2000. 相似文献
945.
Javier Barajas 《Discrete Mathematics》2008,308(8):1355-1365
The distance graph G(D) has the set of integers as vertices and two vertices are adjacent in G(D) if their difference is contained in the set D⊂Z. A conjecture of Zhu states that if the chromatic number of G(D) achieves its maximum value |D|+1 then the graph has a triangle. The conjecture is proven to be true if |D|?3. We prove that the chromatic number of a distance graph with D={a,b,c,d} is five only if either D={1,2,3,4k} or D={a,b,a+b,b-a}. This confirms a stronger version of Zhu's conjecture for |D|=4, namely, if the chromatic number achieves its maximum value then the graph contains K4. 相似文献
946.
Total Domination in Graphs with Given Girth 总被引:1,自引:0,他引:1
A set S of vertices in a graph G without isolated vertices is a total dominating set of G if every vertex of G is adjacent to some vertex in S. The minimum cardinality of a total dominating set of G is the total domination number γ
t
(G) of G. In this paper, we establish an upper bound on the total domination number of a graph with minimum degree at least two in
terms of its order and girth. We prove that if G is a graph of order n with minimum degree at least two and girth g, then γ
t
(G) ≤ n/2 + n/g, and this bound is sharp. Our proof is an interplay between graph theory and transversals in hypergraphs.
Michael A. Henning: Research supported in part by the South African National Research Foundation and the University of KwaZulu-Natal. 相似文献
947.
An analysis has been carried out to study the magnetohydrodynamic boundary layer flow and heat transfer characteristics of a non-Newtonian viscoelastic fluid over a flat sheet with a linear velocity in the presence of thermal radiation and non-uniform heat source. The thermal conductivity is assumed to vary as a linear function of temperature. The basic equations governing the flow and heat transfer are in the form of partial differential equations, the same have been reduced to a set of non-linear ordinary differential equations by applying suitable similarity transformation. The transformed equations are solved analytically by regular perturbation method. Numerical solution of the problem is also obtained by the efficient shooting method, which agrees well with the analytical solution. The effects of various physical parameters such as viscoelastic parameter, Chandrasekhar number, Prandtl number, variable thermal conductivity parameter, Eckert number, thermal radiation parameter and non-uniform heat source/sink parameters which determine the temperature profiles are shown in several plots and the heat transfer coefficient is tabulated for a range of values of said parameters. Some important findings reported in this work reveals that combined effect of variable thermal conductivity, radiation and non-uniform heat source have significant impact in controlling the rate of heat transfer in the boundary layer region. 相似文献
948.
A. S. Khoroshun 《International Applied Mechanics》2008,44(6):703-709
Sufficient conditions for the global PQ-stabilizability of a nonlinear system with uncertainty are established
__________
Translated from Prikladnaya Mekhanika, Vol. 44, No. 6, pp. 126–133, June 2008. 相似文献
949.
Alcohol-water mixtures are often used as model systems for the study of hydrophobic interactions. In this respect, their thermodynamic
properties are of particular interest since precise data are available over the whole miscibility range and they lend themselves
readily to theoretical modelling. Three association models have been used to fit the volume data taken from the literature
for aqueous methonol, ethanol and n-propanol at various temperatures. A simple micellization equilibrium explains the general
trends but fails to fit the reduced excess volumes at both ends of the mole fraction scale. Better fits are obtained if interaction
parameters are introduced, but these two parameters cannot easily be rationalized. A double association model (one for the
alcohol and one for the water) gives the best fit and all the parameters have a physical significance. However, the parameters
extracted, e.g. aggregation numbers, and their trends with temperature are not always realistic. Despite their limitations,
these models illustrate well with the kind of avenues that can be explored to fit and interpret the experimental data of these
complex systems. 相似文献
950.
Mapundi Banda Axel Klar Lorenzo Pareschi Mohammed Seaï d. 《Mathematics of Computation》2008,77(262):943-965
A relaxation system based on a Lattice-Boltzmann type discrete velocity model is considered in the low Mach number limit. A third order relaxation scheme is developed working uniformly for all ranges of the mean free path and Mach number. In the incompressible Navier-Stokes limit the scheme reduces to an explicit high order finite difference scheme for the incompressible Navier-Stokes equations based on nonoscillatory upwind discretization. Numerical results and comparisons with other approaches are presented for several test cases in one and two space dimensions.