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101.
Rohr C Balbás Gambra M Gruber K Höhl C Malarek MS Scherer LJ Constable EC Franosch T Hermann BA 《Chemical communications (Cambridge, England)》2011,47(6):1800-1802
An interaction-site model can a priori predict molecular self-organisation on a new substrate in Monte Carlo simulations. This is experimentally confirmed with scanning tunnelling microscopy on Fréchet dendrons of a pentacontane template. Local and global ordering motifs, inclusion molecules and a rotated unit cell are correctly predicted. 相似文献
102.
Förster T Schunk SA Jentys A Lercher JA 《Chemical communications (Cambridge, England)》2011,47(11):3254-3256
Co and Mn polysiloxanes are unique catalyst/initiator systems for the liquid phase oxidation of o-xylene showing higher activity than Co naphthenates, which is related to the weak interaction of the polar products with the hydrophobic surface as well as the absence of hydroxyl groups and surrounding oxygenates limiting radical quenching. 相似文献
103.
104.
105.
Péter Reischig Lukas Helfen Arie Wallert Tilo Baumbach Joris Dik 《Applied Physics A: Materials Science & Processing》2013,111(4):983-995
The characterisation of the microstructure and micromechanical behaviour of paint is key to a range of problems related to the conservation or technical art history of paintings. Synchrotron-based X-ray laminography is demonstrated in this paper to image the local sub-surface microstructure in paintings in a non-invasive and non-destructive way. Based on absorption and phase contrast, the method can provide high-resolution 3D maps of the paint stratigraphy, including the substrate, and visualise small features, such as pigment particles, voids, cracks, wood cells, canvas fibres etc. Reconstructions may be indicative of local density or chemical composition due to increased attenuation of X-rays by elements of higher atomic number. The paint layers and their interfaces can be distinguished via variations in morphology or composition. Results of feasibility tests on a painting mockup (oak panel, chalk ground, vermilion and lead white paint) are shown, where lateral and depth resolution of up to a few micrometres is demonstrated. The method is well adapted to study the temporal evolution of the stratigraphy in test specimens and offers an alternative to destructive sampling of original works of art. 相似文献
106.
We prove the existence of a hyperbolic surface spread over the sphere for which the projection map has all its singular values
on the extended real line and such that the preimage of the extended real line under the projection map is homeomorphic to
the square grid in the plane. This answers a question raised by è. B. Vinberg.
Supported by the Alexander von Humboldt Foundation.
Supported by NSF grants DMS-0400636, DMS-0244421, and DMS-0244547. 相似文献
107.
108.
An approximation scheme is proposed for calculating electronic excitations in solids. It is described within a projection operator formalism of the Mori-Zwanzig type. The approximation consists in successively limiting the space of dynamical variables which are treated. The selection of the variables is done by making use of the local character of the correlation hole which is surrounding an electron. The method is distinct from a perturbation expansion and can be related to a variational ansatz via the Sauermann functional. The computation of the spectral density of the Green's function is reduced to the diagonalization of matrices. Their dimension depends on the required degree of accuracy of the calculations. The present method can be considered as an extension to excited states of a previously developed. Local Approach for ground state calculations.Dedicated to Prof. S. Methfessel on the occasion of his 60th birthday 相似文献
109.
K Altendorf M Lukas B Kohl C R Müller H Sandermann 《Journal of supramolecular structure》1977,6(2):229-238
110.
A. Chevarier N. Chevarier A. Demeyer A. Alevra I.R. Lukas M.T. Magda M.E. Nistor 《Nuclear Physics A》1975,237(2):354-364
A study of the energy and angular distributions of protons emitted in 3He induced reactions was undertaken at an incident energy of 25.6 MeV. An analysis in the framework of the pre-equilibrium hybrid model did not succeed in explaining the overall behaviour of proton spectra; a contribution due to a break-up or a double stripping of the incident particle has to be taken into account. An attempt was made to account for these processes by performing a phase space calculation. This formulation was firstly tried in the case of deuteron induced reactions for which a break-up mechanism has already been confirmed in continuous proton spectra. The calculation extended to the case of 3He induced reactions showed that a double stripping mechanism could explain the observed distribution. 相似文献