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111.
Tony Shardlow 《BIT Numerical Mathematics》2006,46(1):111-125
We describe a backward error analysis for stochastic differential equations with respect to weak convergence. Modified equations are provided for forward and backward Euler approximations to Itô SDEs with additive noise, and extensions to other types of equation and approximation are discussed. 相似文献
112.
We present in this paper a finite difference solver for Maxwell's equations in non‐staggered grids. The scheme formulated in time domain theoretically preserves the properties of zero‐divergence, symplecticity, and dispersion relation. The mathematically inherent Hamiltonian can be also retained all the time. Moreover, both spatial and temporal terms are approximated to yield the equal fourth‐order spatial and temporal accuracies. Through the computational exercises, modified equation analysis and Fourier analysis, it can be clearly demonstrated that the proposed triple‐preserving solver is computationally accurate and efficient for use to predict the Maxwell's solutions. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
113.
Francisco Hueso-Urea Miguel N. Moreno-Carretero Antonio L. Peas-Chamorro Jos M. Amig Vicente Esteve Tony Debaerdemaeker 《Polyhedron》1999,18(27):1666-3636
From reactions between different Cu(II) salts and the Schiff base 6-amino-5-formyl-1,3-dimethyluracil-benzoylhydrazone (H2BEZDO) in alcohol, six new copper complexes with simplified formulas [Cu(HBEZDO)(H2O)(MeOH)]NO3 (1), [CuCl(HBEZDO)(DMF)] (2), [CuBr(HBEZDO)]·2H2O (3), CuBr(HBEZDO) (4), Cu(ClO4)(HBEZDO)·H2O (5), and Cu(SO4)1/2(HBEZDO)·1
H2O (6) were isolated. The structures of compounds 1, 2 and 3 have been established by means of XRD diffraction methods. In the three compounds, the Schiff base acts as a tridentate monodeprotonated ligand through the N(6), N(51) and O(52) atoms, making two five- and six-membered chelate rings. In the structure of 1 and 2, the solvent molecules are coordinated giving square-based pyramidal environments, with the basal plane completed by a MeOH (1) or Cl (2) and the apical positions occupied by the oxygen atom of a water (1) or a DMF molecule (2). The molecular unit of the complex [CuBr(HBEZDO)]·2H2O (3) is defined by a square-plane containing the three donor atoms of the organic ligand and a bromide ligand (Cu–Br 2.384 Å), but there is a stronger tetragonally elongated pyramidal geometry around the metal, the apical position of the polyhedron being occupied by a weakly bound-to-copper bromine atom (3.086 Å) of a neighbouring molecule. This fact gives the appearance of an apparent dimer with very asymmetric bromine bridges, in which there are no exchange interactions between metal centres. Also, infrared, magnetic and EPR data of the isolated complexes are reported. 相似文献
114.
115.
Yunn-Hwa Ma Ya-Wun Hsu Yeu-Jhy Chang Mu-Yi Hua Jyh-Ping Chen Tony Wu 《Journal of magnetism and magnetic materials》2007
Targeted delivery of thrombolytic drug to the site of emboli exhibits potential to greatly reduce hemorrhagic side effect. A rat embolic model with an easy access of a magnet was established for study of the efficacy of magnetic drug targeting. In anesthetized rats, a whole blood clot produced in vitro was injected from the right iliac artery and lodged in the left iliac artery. Intra-arterial infusion of recombinant tissue plasminogen activator (rt-PA) thereafter significantly reversed the iliac flow within 15 min. Placement of an NdFeB magnet above the left iliac artery caused magnetic nanoparticle retention against hemodynamic dragging force in the presence and absence of the clot. Our results suggest the feasibility of this rat embolic model for the study of magnetic targeted delivery of thrombolytic drugs. 相似文献
116.
We consider wavelet block thresholding method for density estimation. A block-thresholded density estimator is proposed and is shown to achieve optimal global rate of convergence over Besov spaces and simultaneously attain the optimal adaptive pointwise convergence rate as well. These results are obtained in part through the determination of an optimal block length. 相似文献
117.
In this paper, four quadratic hexahedron elements are considered and assessed for analysis of an incompressible viscous flow underlying the mixed finite element method. We classify the investigated elements as multivariant and univariant finite elements. With the same number of pressure unknowns, multivariant elements are more constrained when the number of elements per side is larger than 10, as compared with that of continuous pressure elements. In multivariant eléments, the coding is complicated by the appearance of restricted degrees of freedom at mid-face and mid-edge nodes. The comparison consequently should be made via numerical example against the analytical problem. 相似文献
118.
Freeman Dyson has questioned whether any conceivable experiment in the real universe can detect a single graviton. If not, is it meaningful to talk about gravitons as physical entities? We attempt to answer Dyson’s question and find it is possible concoct an idealized thought experiment capable of detecting one graviton; however, when anything remotely resembling realistic physics is taken into account, detection becomes impossible, indicating that Dyson’s conjecture is very likely true. We also point out several mistakes in the literature dealing with graviton detection and production. 相似文献
119.
120.
Hewison L Johnson TR Mann BE Meijer AJ Sawle P Motterlini R 《Dalton transactions (Cambridge, England : 2003)》2011,40(33):8328-8334
[Fe(L-cysteinate)(2)(CO)(2)](2-) is a CO releasing molecule which has low cytotoxicity to RAW264.7 macrophages. It provides an example of CO binding using ligands available to ion channels which use CO as a signalling molecule in the absence of heme. Previous work has shown that this compound consists of five isomers and it was proposed that the two isomers with trans-dicarbonyls are dominant. In this work the isomers are re-assigned and shown to be capable of releasing CO, albeit too slowly to act as a signalling receptor. It is shown that by linking the two L-cysteines together to form [Fe(SCH(2)CH{CO(2)H}NHCH(2))(2)(CO)(2)], only one isomer is isolated. 相似文献