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991.
A p-adic variation of the Ran(dom) Sa(mple) C(onsensus) method for solving the relative pose problem in stereo vision is developed.
From two 2-adically encoded images a random sample of five pairs of corresponding points is taken, and the equations for the
essential matrix are solved by lifting solutions modulo 2 to the 2-adic integers. A recently devised p-adic hierarchical classification algorithm imitiating the known LBG quantization method classifies the solutions for all
the samples after having determined the number of clusters using the known intra-inter validity of clusterings. In the successful
case, a cluster ranking will determine the cluster containing a 2-adic approximation to the “true” solution of the problem. 相似文献
992.
Eric Berberich Efi Fogel Dan Halperin Michael Kerber Ophir Setter 《Mathematics in Computer Science》2010,4(1):67-91
We describe the algorithms and implementation details involved in the concretizations of a generic framework that enables
exact construction, maintenance, and manipulation of arrangements embedded on certain two-dimensional orientable parametric
surfaces in three-dimensional space. The fundamentals of the framework are described in a companion paper. Our work covers
arrangements embedded on elliptic quadrics and cyclides induced by intersections with other algebraic surfaces, and a specialized
case of arrangements induced by arcs of great circles embedded on the sphere. We also demonstrate how such arrangements can
be used to accomplish various geometric tasks efficiently, such as computing the Minkowski sums of polytopes, the envelope
of surfaces, and Voronoi diagrams embedded on parametric surfaces. We do not assume general position. Namely, we handle degenerate
input, and produce exact results in all cases. Our implementation is realized using Cgal and, in particular, the package that provides the underlying framework. We have conducted experiments on various data sets,
and documented the practical efficiency of our approach. 相似文献
993.
We consider an M/G/1 retrial queue where the service time distribution has a regularly varying tail with index −β, β>1. The waiting time distribution is shown to have a regularly varying tail with index 1−β, and the pre-factor is determined explicitly. The result is obtained by comparing the waiting time in the M/G/1 retrial queue
with the waiting time in the ordinary M/G/1 queue with random order service policy. 相似文献
994.
Let p be a prime and let b be a positive integer. If a (v, k, λ, n) difference set D of order n = p b exists in an abelian group with cyclic Sylow p-subgroup S, then \({p\in\{2,3\}}\) and |S| = p. Furthermore, either p = 2 and v ≡ λ ≡ 2 (mod 4) or the parameters of D belong to one of four families explicitly determined in our main theorem. 相似文献
995.
Wei-Shih Du 《Journal of Global Optimization》2010,47(1):119-132
In this paper, we first establish the existence theorems of the solution of hybrid inclusion and disclusion systems, from
which we study mixed types of systems of generalized quasivariational inclusion and disclusion problems and systems of generalized
vector quasiequilibrium problems. Some applications of existence theorems to feasible points for various mathematical programs
with variational constraints or equilibrium constraints, system of vector saddle point and system of minimax theorem are also
given. 相似文献
996.
Anyue Chen Phil Pollett Junping Li Hanjun Zhang 《Methodology and Computing in Applied Probability》2010,12(3):511-531
We examine basic properties regarding uniqueness, extinction, and explosivity for the generalised Markov branching processes
with pairwise interaction. First we establish uniqueness criteria, proving that in the essentially-explosive case the process
is honest if and only if the mean death rate is greater than or equal to the mean birth rate, while in the sub-explosive case
the process is dishonest only in exceptional circumstances. Explicit expressions are then obtained for the extinction probabilities,
the mean extinction times and the conditional mean extinction times. Explosivity is also investigated and an explicit expression
for mean explosion time is established. 相似文献
997.
Denote by γ the Gauss measure on ℝ
n
and by ${\mathcal{L}}${\mathcal{L}} the Ornstein–Uhlenbeck operator. In this paper we introduce a Hardy space
\mathfrakh1g{{\mathfrak{h}}^1}{{\rm \gamma}} of Goldberg type and show that for each u in ℝ ∖ {0} and r > 0 the operator (rI+L)iu(r{\mathcal{I}}+{\mathcal{L}})^{iu} is unbounded from
\mathfrakh1g{{\mathfrak{h}}^1}{{\rm \gamma}} to L
1γ. This result is in sharp contrast both with the fact that (rI+L)iu(r{\mathcal{I}}+{\mathcal{L}})^{iu} is bounded from H
1γ to L
1γ, where H
1γ denotes the Hardy type space introduced in Mauceri and Meda (J Funct Anal 252:278–313, 2007), and with the fact that in the Euclidean case (rI-D)iu(r{\mathcal{I}}-\Delta)^{iu} is bounded from the Goldberg space
\mathfrakh1\mathbbRn{{\mathfrak{h}}^1}{{\mathbb{R}}^n} to L
1ℝ
n
. We consider also the case of Riemannian manifolds M with Riemannian measure μ. We prove that, under certain geometric assumptions on M, an operator T{\mathcal{T}}, bounded on L
2
μ, and with a kernel satisfying certain analytic assumptions, is bounded from H
1
μ to L
1
μ if and only if it is bounded from
\mathfrakh1m{{\mathfrak{h}}^1}{\mu} to L
1
μ. Here H
1
μ denotes the Hardy space introduced in Carbonaro et al. (Ann Sc Norm Super Pisa, 2009), and
\mathfrakh1m{{\mathfrak{h}}^1}{\mu} is defined in Section 4, and is equivalent to a space recently introduced by M. Taylor (J Geom Anal 19(1):137–190, 2009). The case of translation invariant operators on homogeneous trees is also considered. 相似文献
998.
James M. Calvin 《Journal of Global Optimization》2010,48(1):17-27
This paper considers complexity bounds for the problem of approximating the global minimum of a univariate function when the
function evaluations are corrupted by random noise. We take an average-case point of view, where the objective function is
taken to be a sample function of a Wiener process and the noise is independent Gaussian. Previous papers have bounded the
convergence rates of some nonadaptive algorithms. We establish a lower bound on the convergence rate of any nonadaptive algorithm. 相似文献
999.
Francisco Cribari-Neto Maria da Glória A. Lima 《Annals of the Institute of Statistical Mathematics》2010,62(6):1053-1082
The linear regression model is commonly used by practitioners to model the relationship between the variable of interest and
a set of explanatory variables. The assumption that all error variances are the same, known as homoskedasticity, is oftentimes
violated when cross sectional data are used. Consistent standard errors for the ordinary least squares estimators of the regression
parameters can be computed following the approach proposed by White (Econometrica 48:817–838, 1980). Such standard errors,
however, are considerably biased in samples of typical sizes. An improved covariance matrix estimator was proposed by Qian
and Wang (J Stat Comput Simul 70:161–174, 2001). In this paper, we improve upon the Qian–Wang estimator by defining a sequence
of bias-adjusted estimators with increasing accuracy. The numerical results show that the Qian–Wang estimator is typically
much less biased than the estimator proposed by Halbert White and that our correction to the former can be quite effective
in small samples. Finally, we show that the Qian–Wang estimator can be generalized into a broad class of heteroskedasticity-consistent
covariance matrix estimators, and our results can be easily extended to such a class of estimators. 相似文献
1000.
We consider the combined hubbing and routing problem in postal delivery systems and develop an iterative two-stage solution
procedure for the problem. In the first stage, hub locations are determined and postal offices are multiply allocated to the
hubs. The second stage gives the routes in hub regions that alter the distances between points used in the hub-location problem.
The procedure then iterates between two stages by updating the distances used in hubbing in order to produce a route-compatible
hub configuration. Computational experience is reported for the test problems taken from the literature. For a case study
Turkish postal delivery system data are utilized. As the case study is applied on a road network, a final stage, seeking improvements
based on special structures in the routed network, is appended to the two-stage solution procedure. 相似文献