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101.
Mujahid Kamran 《理论物理通讯》1995,23(3):379-382
Using perturbative QCD in conjunction with CVC and standard electroweak theory, it is shown that at large Q2, F1n/F1P = F2n/F1P = -0.69. The comparison with other results on form factor ratios from QCD sum rules and/or PQCD is carried out. 相似文献
102.
Mu jahid Kamran 《理论物理通讯》1985,4(2):277-280
It is pointed out that the Donnachie-Landshoff model does not agree with the collider b-data. A non-linear pomeron trajectory is introduced in the model to remedy this defect. 相似文献
103.
This paper reports the development of a molecular fluorescence spectroscopy-based approach for the determination of cadmium in seawater. Anthrylazamacrocycle derivatives—the fluorescence of which is enhanced when chelated to zinc or cadmium—are used as chemosensors. A detection limit of 5 nM has been found at pH 10 for both metals, and spectral shifts allow simultaneous Cd(II)/Zn(II) determination using multiwavelength analysis. While cadmium emission behavior is similar at pH 13, zinc is not detected anymore. This enables the selective detection of cadmium even at a high Zn(II)/Cd(II) ratio. The detection limit is 1 nM. Interferent removal and preconcentration have been developed using a Dowex resin, with a view to determine cadmium in seawater. A global procedure including interferent elimination, cadmium preconcentration (30 fold), and fluorescence detection at pH 13 has been evaluated on certified reference material SLEW-2. 相似文献
104.
105.
Afsaneh Fatemi Kamran Zamanifar Naser NematBakhsh 《Applied mathematics and computation》2007,190(2):1514-1525
Many definitive and approximate methods have been so far proposed for the construction of an optimal binary search tree. One such method is the use of evolutionary algorithms with satisfactorily improved cost efficiencies. This paper will propose a new genetic algorithm for making a near-optimal binary search tree. In this algorithm, a new greedy method is used for the crossover of chromosomes while a new way is also developed for inducing mutation in them. Practical results show a rapid and desirable convergence towards the near-optimal solution. The use of a heuristic to create not so costly chromosomes as the first offspring, the greediness of the crossover, and the application of elitism in the selection of future generation chromosomes are the most important factors leading to near-optimal solutions by the algorithm at desirably high speeds. Due to the practical results, increasing problem size does not cause any considerable difference between the solution obtained from the algorithm and exact solution. 相似文献
106.
Summary Let Fn, n≧ 1, denote the sequence of generic filiform (connected, simply connected) Lie groups. Here we study, for each Fn, the infinite dimensional simple quotients of the group C*-algebra of (the most obvious) one of its discrete cocompact subgroups Dn. For Dn, the most attractive concrete faithful representations are given in terms of Anzai flows, in analogy with the representations
of the discrete Heisenberg group H3 ⊆G3 on L2(T) that result from the irrational rotation flows on T; the representations of Dn generate infinite-dimensional simple quotients An,θ of the group C*-algebra C*(Dn). For n>1, there are other infinite-dimensional simple quotients of C*(Dn) arising from non-faithful representations of Dn. Flows for these are determined, and they are also characterized and represented as matrix algebras over simple affine Furstenberg
transformation group C*-algebras of the lower dimensional tori. 相似文献
107.
Popescu G Deflores LP Vaughan JC Badizadegan K Iwai H Dasari RR Feld MS 《Optics letters》2004,29(21):2503-2505
By use of the Fourier decomposition of a low-coherence optical image field into two spatial components that can be controllably shifted in phase with respect to each other, a new high-transverse-resolution quantitative-phase microscope has been developed. The technique transforms a typical optical microscope into a quantitative-phase microscope, with high accuracy and a path-length sensitivity of lambda/5500, which is stable over several hours. The results obtained on epithelial and red blood cells demonstrate the potential of this instrument for quantitative investigation of the structure and dynamics associated with biological systems without sample preparation. 相似文献
108.
109.
F.?FinsterEmail author N.?Kamran J.?Smoller S.-T.?Yau 《Communications in Mathematical Physics》2005,260(2):257-298
We consider the scalar wave equation in the Kerr geometry for Cauchy data which is smooth and compactly supported outside
the event horizon. We derive an integral representation which expresses the solution as a superposition of solutions of the
radial and angular ODEs which arise in the separation of variables. In particular, we prove completeness of the solutions
of the separated ODEs.
This integral representation is a suitable starting point for a detailed analysis of the long-time dynamics of scalar waves
in the Kerr geometry.
Research supported by NSERC grant # RGPIN 105490-2004.
Research supported in part by the NSF, Grant No. DMS-010-3998.
Research supported in part by the NSF, Grant No. 33-585-7510-2-30. 相似文献
110.
Kamran Izadpanah Robert L. Harder Raj Kansakar Mike Reymond 《Finite Elements in Analysis and Design》1991,7(4):331-342
A general-purpose fluid-structure interaction capability which can be used in analyzing internal acoustic problems in automobiles and aircraft has been formulated. This capability has become an important issue in the last few years because of the emphasis that has been placed on noise control in all vehicles. A variety of output features that are needed by the analyst in identifying the causes of the acoustic problems have been studied and implemented. The fluid (air) is modeled as an inviscid, irrotational fluid with pressure variables as the degrees of freedom. An acoustic absorber element and an acoustic barier element are also implemented. 相似文献