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51.
In this paper, we consider nonlinear Schrödinger (NLS) equations, both in the anomalous and normal dispersive regimes, which govern the propagation of a single field in a fiber medium with phase modulation and fibre gain (or loss). The integrability conditions are arrived from linear eigen value problem. The variable transformations which connect the integrable form of modified NLS equations are presented. We succeed in Hirota bilinearzing the equations and on solving, exact bright and dark soliton solutions are obtained. From the results, we show that the soliton is alive, i.e. pulse area can be conserved by the inclusion of gain (or loss) and phase modulation effects. 相似文献
52.
Y Dimitrova 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2001,57(12):2457-2462
The changes in the vibrational characteristics characterizing the dimerization of nitric acid have been investigated by ab initio calculations at the MP2 level, with 6-31G(d,p) and 6-31 + G(d,p) basis sets, and B3LYP/6-31G(d,p) calculations. The most consistent agreement between the computed values of the frequency shifts for the planar fully symmetric structure (2A) and those experimentally observed suggests that this structure is preferred. It was established that the most sensitive to the complexation is the stretching O-H vibration. The values of the frequency shift (-306 cm(-1)) is indicative for the formation of the relatively strong hydrogen bonds. The calculations predict an increase of the infrared intensity of the stretching O-H vibration in the nitric acid dimer more than 26 times. 相似文献
53.
54.
By using spectroscopic and colloidal chemistry methods we studied the interactions of globular proteins with phospholipid membranes in relation to protein-promoted membrane fusion. We considered the effect of protein sorption on the destabilization of phosphatidylcholine and phosphatidylserine liposome membranes. Experimentally, we injected the proteins into fluorophore-quencher embedded liposome dispersions and recorded the leakage of fluorophore-quencher from the liposomes' inner compartment, which is due to the protein-induced destabilization of the phospholipid membranes. The release of fluorophore-quencher strongly depends on the protein concentration. The existence of monovalent and polyvalent cations also influences the protein-induced membrane destabilization by affecting the hydrophobic and electrostatic interactions. 相似文献
55.
The study of the IR spectral data for metallated acetonitrile (counter ions Li+, Na+, K+ in solvents tetrahydrofuran, THF, and hexamethylphosphotriamide, HMPT) and its D3? and 15N- derivatives together with and normal coordinate calculations showed that the mesomeric ion H2CCN has a favoured planar structure and the carbon-metal bond has a pronounced ionic character. 相似文献
56.
Olga Yakubovich Galina Kiriukhina Anatoliy Volkov Olga Dimitrova 《Acta Crystallographica. Section C, Structural Chemistry》2019,75(5):514-522
A novel phosphate, sodium zinc aluminium bis(phosphate), NaZnAl(PO4)2, was obtained under mild‐temperature hydrothermal conditions at 553 K. The crystal structure has been studied using single‐crystal X‐ray experimental data. The pseudo‐hexagonal phase NaZnAl(PO4)2 crystallizes in the monoclinic space group P21/c. Its unique crystal structure is based on a three‐dimensional (3D) framework built by Zn‐, Al‐ and P‐centred tetrahedra sharing vertices. Channels parallel to the [101] and [01] directions are limited by six‐ and eight‐membered windows, and incorporate Na atoms. The new compound is discussed as a member of the morphotropic series AMM′PO4, where A = Na, K, Rb or NH4, M = Cu, Ni, Co, Fe, Zn or Mg and M′ = Fe, Al or Ga. The title compound is the first Na representative within the series and is characterized by a 3D architecture of tetrahedra populated in an ordered manner by Zn2+, Al3+ and P5+ ions. 相似文献
57.
JIANG DiHua NIEN ChuFeng & QIN YuJun School of Mathematics University of Minnesota Minneapolis MN USA 《中国科学 数学(英文版)》2010,(3)
In this paper, we summarize the basic structures and properties of irreducible symplectic supercuspidal representations of GLn(F) over a p-adic local field F with characteristic zero, and explore possible topics for further investigation. 相似文献
58.
Belokoneva E. L. Eremina T. A. Dimitrova O. V. Volkov A. S. 《Crystallography Reports》2021,66(1):95-104
Crystallography Reports - Crystals of a new complex layered lead carbonate silicate Pb19.4Na1.9[Si10O25](CO3)9(OH)12.7 ? 1.3H2O and lead silicogermanate... 相似文献
59.
A new lead-sodium borosilicate (Pb4.8Na1.2)[Si8(Si1.2B0.8)O25] (a = 9.5752 and c = 42.565 ?; space group R
$
\bar 3
$
\bar 3
c) is synthesized under hydrothermal conditions, and its crystal structure is determined without preliminary knowledge of the
chemical formula. The anionic radical of a new type is a double layer in which one of the three independent Si-tetrahedra
contains an isomorphous boron admixture. Its topological relationship with the radicals in the structures of benitoite and
langasite, as well as in the structures of lead silicates barisilite and hyttsjoeite, is found based on the block consisting
of an octahedron and six tetrahedra. This allows one to consider that the new layer is derived from the hyttsjoeite layer
by the replacement of the octahedron with two tetrahedra and the increase of the silicon fraction. Although lead atoms are
located between the layers in the intersheet space, they form relatively strong bonds with silicon-oxygen layers. This structural
type is a collector of heavy metals. 相似文献
60.
Dimitrova Y Daskalova LI 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2009,71(5):1720-1727
The vibrational characteristics (vibrational frequencies and infrared intensities) for the hydrogen-bonded systems of nicotinamide (NA(Z) and NA(E)) with dimethyl sulfoxide (DMSO) have been predicted using ab initio SCF/6-31G(d,p) and DFT (BLYP/6-311++G(d,p)) calculations. The changes in the vibrational characteristics from free monomers to a complex have been calculated. The ab initio and BLYP calculations show that the complexation between nicotinamide (NA(Z) and NA(E)) and DMSO leads to large red shifts of the stretching vibrations for the hydrogen-bonded N-H bonds of nicotinamide and very strong increase in their IR intensity. The results from the BLYP/6-311++G(d,p) calculations show that the predicted red shifts of the nu(s)(NH) and nu(as)(NH) vibrations for the complex NA(E)-DMSO (1:2) (Deltanu(as)(NH)=-186 cm(-1) and Deltanu(s)(NH)=-198 cm(-1)) are in better agreement with the experimentally measured. The magnitudes of the wavenumber shifts are indicative of strong NH...O hydrogen-bonded interactions in both complexes. The calculations predict an increase of the IR intensity of nu(s)(NH) and nu(as)(NH) vibrations in the complexes up to 14 times. Having in mind that in more cases the predicted changes in the vibrational characteristics for the complexes studied are very near, it could be concluded that both conformers of nicotinamide, Z-conformer and E-conformer, are present in the solution forming the hydrogen-bonded complexes with DMSO. 相似文献