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71.
Mathur M DasGupta R Selvi NR John NS Kulkarni GU Govindarajan R 《Physical review letters》2007,98(16):164502
Hydraulic jumps created by gravity are seen everyday in the kitchen sink. We show that at small scales a circular hydraulic jump can be created in the absence of gravity by surface tension. The theory is motivated by our experimental finding of a height discontinuity in spreading submicron molten metal droplets created by pulsed-laser ablation. By careful control of initial conditions, this leads to solid femtoliter cups of gold, silver, copper, niobium, and tin. 相似文献
72.
K. Shivashankar Manohar V. Kulkarni Lokesh A. Shastri Vijaykumar P. Rasal Sandur V. Rajendra 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):2187-2200
Various 4-aryloxymethylcoumarins have been obtained by the r.t. allylic substitution with formylphenols. These have been further reacted with o-aminothiophenol resulting in the formation of a benzothiazole skeleton. These compounds have been synthesised with a view to study their potential as microbial growth inhibitors. Comparative studies on the spectral and antimicrobial activities have also been carried out. 相似文献
73.
I. Banerjee Soumen Karmakar Naveen V. Kulkarni Ashok B. Nawale V. L. Mathe A. K. Das S. V. Bhoraskar 《Journal of nanoparticle research》2010,12(2):581-590
The synthesis of nanoparticles of titanium dioxide (TiO2) with varying percentages of anatase and rutile phases is reported. This was achieved by controlling the operating pressure
in a transferred-arc, direct current thermal plasma reactor in which titanium vapors are evaporated, and then exposed to ambient
oxygen. The average particle size remained around 15 nm in each case. The crystalline structure of the as-synthesized nanoparticles
of TiO2 was studied with X-ray diffraction analysis; whereas the particle morphology was investigated with the help of transmission
electron microscopy. The precursor species responsible for the growth of these nanoparticles was studied with the help of
optical emission spectroscopy. As inferred from the X-ray diffraction analysis, the relative abundance of anatase TiO2 was found to be dominant when synthesized at 760 Torr, and the same showed a decreasing trend with decreasing chamber pressure.
The study also reveals that anatase TiO2 is a more effective photocatalytic agent in degrading methylene blue by comparison to its rutile phase. 相似文献
74.
Conjunctive modelling of free/porous flows provides a powerful and cost‐effective tool for designing industrial filters used in the process industry and also for quantifying surface–subsurface flow interactions, which play a significant role in urban flooding mechanisms resulting from sea‐level rise and climate changes. A number of well‐established schemes are available in the literature for simulation of such regimes; however, three‐dimensional (3D) modelling of such flow systems still presents numerical and practical challenges. This paper presents the development of a fully 3D, transient finite element model for the prediction and quantitative analyses of the hydrodynamic behaviour encountered in industrial filtrations and environmental flows represented by coupled flows. The weak‐variational formulation in this model is based on the use of C0 continuous equal‐order Lagrange polynomial functions for velocity and pressure fields represented by 3D hexahedral finite elements. A mixed UVWP finite element scheme based on the standard Galerkin technique satisfying the Ladyzhenskaya–Babuska–Brezzi stability criterion through incorporation of an artificial compressibility term in the continuity equation has been employed for the solution of coupled partial differential equations. We prove that the discretization generates unified stabilization for both the Navier–Stokes and Darcy equations and preserves the geometrical flexibility of the computational grids. A direct node‐linking procedure involving the rearrangement of the global stiffness matrix for the interface elements has been developed by the authors, which is utilized to couple the governing equations in a single model. A variety of numerical tests are conducted, indicating that the model is capable of yielding theoretically expected and accurate results for free, porous and coupled free/porous problems encountered in industrial and environmental engineering problems representing complex filtration (dead‐end and cross‐flow) and interacting surface–subsurface flows. The model is computationally cost‐effective, robust, reliable and easily implementable for practical design of filtration equipments, investigation of land use for water resource availability and assessment of the impacts of climatic variations on environmental catastrophes (i.e. coastal and urban floods). The model developed in this work results from the extension of a multi‐disciplinary project (AEROFIL) primarily sponsored by the European aerospace industries for development of a computer simulation package (Aircraft Cartridge Filter Analysis Modelling Program), which was successfully utilized and deployed for designing hydraulic dead‐end filters used in Airbus A380.Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
75.
Mahesh P. Kulkarni Timothy J. Peckham Owen D. Thomas Steven Holdcroft 《Journal of polymer science. Part A, Polymer chemistry》2013,51(17):3654-3666
A series of highly sulfonated, ether‐containing polybenzimidazoles (SOPBI) with controlled sulfonation degrees were synthesized from various stoichiometric ratio mixtures of sodium 6,6'‐oxybis(3‐carboxybenzenesulfonate) (SODBA), 4,4'‐oxydibenzoic acid (ODBA), and 3,3'‐diaminobenzidine (DAB) by solution copolycondensation in poly(phosphoric acid). The resulting sulfonated polymers were further sulfonated by grafting of pendant sulfonic acid chains via a reaction of 1,3‐propane sultone with lithiated‐N of the imidazole rings in the polymer backbone, yielding materials with high, absolute IEC values (3.42–4.15 meq g?1). Due to self‐neutralization, the solid state polymers possessed “free” acid content of 1.40 to 2.15 meq g?1, were soluble in organic solvents yet insoluble in aqueous solution, while displaying proton conductivites (11–47 mS cm?1) at elevated temperatures (80 °C, 95% RH). © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3654–3666 相似文献
76.
77.
V. J. Rao V. S. Kulkarni S. S. Katti 《Applied Physics A: Materials Science & Processing》1990,50(5):499-502
We report the results of passivation of n-GaAs surface by Langmuir-Blodgett films. The capacitance-voltage and current-voltage characteristics in a metal-insulator-semiconductor configuration fabricated using films as insulators, show that the frequency dispersion of the accumulation capacitance is small, indicating that the high frequency capacitance under accumulation is due to the LB film. It has been shown that it reduces the surface barrier characteristic of GaAs surfaces, and may offer hope for unpinning the surface Fermi level. We offer a possible explanation for these findings in terms of the advanced unified defect and the effective work function models. 相似文献
78.
Rajesh S. Kulkarni 《Proceedings of the American Mathematical Society》2008,136(10):3375-3382
In this note, we show that down-up algebras at roots of unity are maximal orders over their centers.
79.
Electronic charge density distribution in molecular systems has been described in terms of the topological properties. After briefly reviewing methods of obtaining charge densities from X-ray diffraction and theory, typical case studies are discussed. These studies include rings and cage systems, hydrogen bonded solids, polymorphic solids and molecular NLO materials. It is shown how combined experimental and theoretical investigations of charge densities in molecular crystals can provide useful insights into electronic structure and reactivity. 相似文献
80.
AbstractGraphene is emerged as a highly sought after reinforcing filler for epoxy matrix in view of its superior electrical, mechanical and thermal properties. Dispersion of low concentration of graphene can significantly enhance the epoxy/graphene nanocomposites properties. Dispersion of graphene in epoxy matrix depends on processing protocols used, and interfacial interaction between epoxy matrix and graphene. Interfacial interaction between epoxy matrix and graphene can be achieved by covalent and non-covalent modification of graphene. This paper comprehensively review the influence of different processing protocols adopted for the processing of epoxy/graphene nanocomposites, and its effect on mechanical, thermal and electrical properties. In addition, covalent and non-covalent strategies adopted for modification of graphene, and its influence on mechanical, thermal and electrical properties of epoxy/graphene nanocomposites are extensively discussed. The future challenges associated with graphene reinforced epoxy nanocomposites processing have been discussed. 相似文献