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A bounded univalent function in $\bigcup_{p>1}B^{p}$\bigcup_{p>1}B^{p} but not in the logarithmic Bloch space. 相似文献
994.
Matías Toril Volker Wille Iñigo Molina-Fernández Chris Walshaw 《Journal of Heuristics》2011,17(5):615-635
In mobile network design, the problem of assigning network elements to controllers when defining network structure can be
modeled as a graph partitioning problem. In this paper, a comprehensive analysis of a sophisticated graph partitioning algorithm
for grouping base stations into packet control units in a mobile network is presented. The proposed algorithm combines multi-level
and adaptive multi-start schemes to obtain high quality solutions efficiently. Performance assessment is carried out on a
set of problem instances built from measurements in a live network. Overall results confirm that the proposed algorithm finds
solutions better than those obtained by the classical multi-level approaches and much faster than classical multi-start approaches.
The analysis of the optimization surface shows that the best local minima values follow a Gumbel distribution, which justifies
the stagnation of naive multi-start approaches after a few attempts. Likewise, the analysis shows that the best local minima
share strong similarities, which is the reason for the superiority of adaptive multi-start approaches. Finally, a sensitivity
analysis shows the best internal parameter settings in the algorithm. 相似文献
995.
We survey recent results on domination properties of strictly singular operators and related operator ideals, as well as Banach–Saks
operators, Narrow operators and p-summing operators. 相似文献
996.
Numerical Algorithms - Multi-frequency, highly oscillatory Hamiltonian problems derive from the mathematical modelling of many real-life applications. We here propose a variant of Hamiltonian... 相似文献
997.
Miguel A. Hernndez‐Vern Natalia Romero 《Mathematical Methods in the Applied Sciences》2019,42(17):5856-5866
In this paper, we study the quadratic matrix equations. To improve the application of iterative schemes, we use a transform of the quadratic matrix equation into an equivalent fixed‐point equation. Then, we consider an iterative process of Chebyshev‐type to solve this equation. We prove that this iterative scheme is more efficient than Newton's method. Moreover, we obtain a local convergence result for this iterative scheme. We finish showing, by an application to noisy Wiener‐Hopf problems, that the iterative process considered is computationally more efficient than Newton's method. 相似文献
998.
Background
Hydrogels are crosslinked polymer networks that can absorb and retain a large fraction of liquid. Near a critical sliding velocity, hydrogels pressed against smooth surfaces exhibit time-dependent frictional behavior occurring over multiple timescales. The origin of these dynamics is unresolved ObjectiveHere, we characterize this time-dependent regime and show that it is consistent with two distinct molecular processes: sliding-induced relaxation and quiescent recovery. MethodsOur experiments use a custom pin-on-disk tribometer to examine poly(acrylic acid) hydrogels on smooth poly(methyl methacrylate) surfaces over a variety of sliding conditions, from minutes to hours. ResultsWe show that at a fixed sliding velocity, the friction coefficient decays exponentially and reaches a steady-state value. The time constant associated with this decay varies exponentially with the sliding velocity, and is sensitive to any precedent frictional shearing of the interface. This process is reversible; upon cessation of sliding, the friction coefficient recovers to its original state. We also show that the initial direction of shear can be imprinted as an observable “memory”, and is visible after 24 hrs of repeated frictional shearing. ConclusionsWe attribute this behavior to nanoscale extension and relaxation dynamics of the near-surface polymer network, leading to a model of frictional relaxation and recovery with two parallel timescales. 相似文献999.
Privacy-preserving data splitting is a technique that aims to protect data privacy by storing different fragments of data in different locations. In this work we give a new combinatorial formulation to the data splitting problem. We see the data splitting problem as a purely combinatorial problem, in which we have to split data attributes into different fragments in a way that satisfies certain combinatorial properties derived from processing and privacy constraints. Using this formulation, we develop new combinatorial and algebraic techniques to obtain solutions to the data splitting problem. We present an algebraic method which builds an optimal data splitting solution by using Gröbner bases. Since this method is not efficient in general, we also develop a greedy algorithm for finding solutions that are not necessarily minimally sized. 相似文献1000.
Iulian Preda Leonardo Soriano Daniel Díaz‐Fernández Guillermo Domínguez‐Cañizares Alejandro Gutiérrez Germán R. Castro Jesús Chaboy 《Journal of synchrotron radiation》2013,20(4):635-640
This work reports an X‐ray absorption near‐edge structure (XANES) spectroscopy study at the Ni K‐edge in the early stages of growth of NiO on non‐ordered SiO2, Al2O3 and MgO thin films substrates. Two different coverages of NiO on the substrates have been studied. The analysis of the XANES region shows that for high coverages (80 Eq‐ML) the spectra are similar to that of bulk NiO, being identical for all substrates. In contrast, for low coverages (1 Eq‐ML) the spectra differ from that of large coverages indicating that the local order around Ni is limited to the first two coordination shells. In addition, the results also suggest the formation of cross‐linking bonds Ni—O—M (M = Si, Al, Mg) at the interface. 相似文献
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