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1.
Cover Picture: A new topological insulator built from quasi one‐dimensional atomic ribbons (Phys. Status Solidi RRL 2/2015) 下载免费PDF全文
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In this paper, we present a smoothing technique which can be understood as a Quasi-Newton method. The idea of this preconditioner is that it approximates the symbol of the inverse Hessian, which has smoothing behavior. This symbol is derived analytically for the Stokes equations and investigated numerically for a flow with a Reynolds number of 80. The resulting symbol is then approximated by differential operators, which will lead to a method similar to Sobolev Smoothing. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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We show theoretically and experimentally that associative connections between image structures are performed with advantage in thick media. 相似文献
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For certain conditions the afterglow of low pressure discharges can be dominated by three body recombination. These conditions — electron densities of about 1012 cm?3 and electron temperatures of about 500 °K— are realized 20 μsec after switch off of the discharge for gas pressures (hydrogen) between 2 and 6 mTorr. In this pressure range the energy transfer from the electrons via the ions to the neutrals and subsequently to the wall is high enough to permit a decay of the electron temperature to low values before the electron density has decreased appreciably. A theoretical model demonstrates that the electron density decaydn e/dt~n e 3 f(T e) is in good approximation equivalent todn e/dt=const·n e 2 for a certain range of time and of parameters. This proportionality is observed. The measured values of the constant differ from the calculated ones by about 15%. 相似文献
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The previously proposed flat 2,6-diauro-1,5-naphthyridine polymers were bent to closed rings with up to 12 monomers. Their bending energies and lowest in-plane deformation frequencies were calculated at the DFT level using quasirelativistic pseudopotentials for gold. The ring-formation energies were compared with those for polyacene rings and found to be of the same order of magnitude, suggesting sufficient stability for the predicted polyauronaphthyridines. As function of the ring radius, r, the frequencies and deformation energies were shown to behave as r(-2) and r(-1), respectively. The molecules thus behave as classical elastic bodies. 相似文献
7.
High-precision calculations are reported for the title series with M=Cu, Ag, Au, using CCSD(T) with the latest pseudopotentials and basis sets up to cc-pVQZ. The bond lengths for M=Cu, Ag, Au agree with experiment within better than 1 pm. The role of deep-core excitations is studied. The second-order spin-orbit effects are evaluated at the density functional theory level, including M=Rg. A qualitative bonding analysis suggests multiple M-C bonding. The calculated vibrational frequencies are expected to be more accurate than the available experimental estimates. The M-C bond lengths obey Cu相似文献
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The basis-set limit of the aurophilic attraction is studied at the MP2 level for the free model dimer [ClAuPH(3)](2) and for a [P(AuPH(3))(4)](+) ion. The latter system is found to prefer a C(4v) symmetry, instead of T(d), in agreement with Li and Pyykko [Inorg. Chem. 32, 2630 (1993)] but in contradiction to recent results of Fang and Wang [J. Phys. Chem. A. 111, 1562 (2006)]. The Karlsruhe split valence and the Dunning correlation-consistent basis sets converge to the same limit. 相似文献
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A wide decomposition pressure range of 132 GPa is predicted for PbH4 above which it emerges in very different forms compared with its group-14 congeners. This triply Born-Oppenheimer system is a nonmolecular, three-dimensional, metallic alloy, despite a prominent layered structure. A significant number of enthalpically near-degenerate structures, with exceedingly small energy barriers for distortions, and characteristic instabilities in the phonon spectra suggest that even at very high pressures PbH4 may exhibit both metallic and liquidlike properties and sublattice or even full melting. 相似文献
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Ahuja R Blomqvist A Larsson P Pyykkö P Zaleski-Ejgierd P 《Physical review letters》2011,106(1):018301
The energies of the solid reactants in the lead-acid battery are calculated ab?initio using two different basis sets at nonrelativistic, scalar-relativistic, and fully relativistic levels, and using several exchange-correlation potentials. The average calculated standard voltage is 2.13?V, compared with the experimental value of 2.11?V. All calculations agree in that 1.7-1.8?V of this standard voltage arise from relativistic effects, mainly from PbO2 but also from PbSO4. 相似文献