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21.
Enrique J. Baran 《Journal of fluorine chemistry》1981,17(6):543-548
Mean amplitudes of vibration for the cations ClF+4, BrF+4 and IF+4 have been calculated using the ‘Method of the Characteristic Vibrations’ and recently revised spectroscopic data. The results are briefly discussed and some comparisons with isoelectronic molecules and other related species are made. 相似文献
22.
Irma L. Botto Enrique J. Baran José C. Pedregosa Pedro J. Aymonino 《Monatshefte für Chemie / Chemical Monthly》1979,110(4):895-898
The infrared and laser-Raman spectra of crystalline Ba2V2O7 are reported and discussed by means of a Site Symmetry analysis.
28. Mitt. der Reihe Orthovanadate und verwandte Verbindungen. 27. Mitt.:E. J. Baran undM. E. Escobar, J. Phys. Chem. Solids, im Druck; 26. Mitt.:E. J. Baran, I. L. Botto, J. F. Ramos undP. J. Aymonino, Mh. Chem.109, 1139 (1978); 25. Mitt.:E. J. Baran, J. Mol. Struct.48, 441 (1978); 24. Mitt.:E. J. Baran undI. L. Botto, J. inorg. nucl. Chem.40, 1603, (1978); 23. Mitt.:M. E. Escobar undE. J. Baran, Z. Anorg. allg. Chem.,441, 273 (1978). 相似文献
23.
Prof. Dr. Enrique J. Baran 《Monatshefte für Chemie / Chemical Monthly》1975,106(1):121-126
Mean amplitudes of vibration of a series of tetrahedralXY 4 molecules and ions (hydrides, halides, oxides and oxoanions) have been calculated using the “Method of the Characteristic Vibrations” ofA. Müller. The results indicate that this method leads to very good values for most of the investigated species, and especially in the cases of highM X/MY mass ratio. 相似文献
24.
I.R. Spectra of Some Double Oxides of the Type Te3MIVO8 The infrared spectra of the phases Te3MIVO8 (MIV = Ti, Zr, Hf, Sn), structurally related to fluorite, have been recorded and discussed. It is shown that all the observed have a complex origin, and it is not possible to assign them to definite vibrations of the metal-oxygen polyhedra present in the lattices. 相似文献
25.
J. Baran 《Journal of Molecular Structure》1987,162(3-4):229-245
The polarized absorption infrared spectra of CsHSeO4 and CsDSeO4 single crystals and polarized Raman spectra of the CsHSeO4 single crystal were measured at room temperature. The polarization features of the internal vibrations of the HSeO−4 ions are predicted on the basis of the X-ray structure assuming strong couping between the vibrations of the two shortest Se---O bonds and an intermediate Se---O bond. The bending methods γOH and δOH of a hydrogen bond appear at 805 cm− and 1258 cm−1, respectively. The νOH absorption has the ABC structure due to Fermi resonance of νOH with the overtones of the δOH and γOH vibrations. A similar shape of the νOH band is observed in the Raman spectra. The νOD absorption has a different shape from that of νOH. Intra-chain coupling was observed for the νOH and νOD vibrations. 相似文献
26.
The infrared and laser-Raman spectra of crystalline Mg3(VO4)2 are reported and a factor group analysis for the full lattice is presented to support the discussion. The 1,000 to 600 cm?1 region of the spectrum is essentially related to internal (stretching) modes of the greatly distorted VO4 tetrahedra, whereas the bands in the low frequency region must be assigned to complex vibrations originating in the interaction of the bending vibrations of the tetrahedral groups with the external modes. 相似文献
27.
Baran J Pawlukojć A Majerz I Malarski Z Sobczyk L Grech E 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2000,(9):1801-1812
The infra-red (IR), Raman (R) and inelastic incoherent neutron scattering (IINS) spectra, particularly in low frequency region, of the title ionic adduct were studied. It is shown that all low frequency vibrations (below 200 cm(-1)) of (CH3)2N groups of protonated 1,8-bis(dimethylamino)naphthalene (DMAN)--clearly observed in IINS spectra--are sensitive to the environment, i.e. to the type of counterion forming short contacts with C-H bonds of methyl groups. The internal frequencies were also calculated by ab initio method. The results are consistent with numerous observations of the counteranion effect on the geometry of the protonated DMAN. The conclusions are compared with structural and NMR studies reported recently for the 1,8-bis(dimethylamino)naphthalene with dichloromaleic acid (DMAN x DCM) adduct. The single crystal R polarized spectra taken over the frequency range 20-3200 cm(-1) were analyzed in detail. We have shown that a substantial difference in the IR spectrum of the dichloromaleic acid (DCM) anion in the DMAN adduct and in the potassium salt results from different geometries of OHO hydrogen bonds. In the case of potassium salt the chains of longer intermolecular hydrogen bonds are formed described by means of a double minimum potential. 相似文献
28.
Five new representatives of the cembrane class of marine natural products have been isolated as minor metabolites from an undescribed species of Eunicea, a sea whip collected near the Colombian Southwestern Caribbean Sea. The structure of the crystalline metabolite 1 was solved by single-crystal X-ray diffraction analysis. Structures could then be proposed for cembradienes 2-5 by comprehensive spectral analyses involving 2D NMR, IR, UV, and high-resolution mass spectrometry, as well as chemical interconversion studies. Compound 1 exhibited weak cytotoxicity in the NCI 3-cell line panel human cancer screening program, whereas compounds 1, 2 and 4 displayed significant antiplasmodial activity against Plasmodium falciparum. 相似文献
29.
L. M. Babkov J. Baran N. A. Davydova J. I. Kukielskii S. V. Trukhachev 《Journal of Structural Chemistry》2004,45(4):591-598
The vibrational spectra of a solid crystalline sample of 2-biphenylmethanol have been measured at room temperature. The IR absorption spectra were recorded in the range 400 cm–1–3600 cm–1; Raman spectra were measured in the range 10 cm–1–1640 cm–1. The direct mechanical and optoelectronic problems were solved using the fragment method realized as Lev-100 software; the intensity distribution in the IR spectrum of 2-biphenylmethanol was obtained by the same method. The experimental Raman and IR absorption spectra were interpreted by analyzing the calculated data on the frequencies and forms of normal vibrations and their intensities in the IR spectra. IR absorption spectra were simulated for several models of 2-biphenylmethanol conformers that differ in the mutual orientation of fragments. Based on the results of simulation and comparison of the calculated and experimental spectra of conformers we suggested a model for the conformer realized in the solid phase under normal conditions.Original Russian Text Copyright © 2004 by L. M. Babkov, J. Baran, N. A. Davydova, J. I. Kukielskii, and S. V. TrukhachevTranslated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 4, pp. 624–631, July–August, 2004.This revised version was published online in April 2005 with a corrected cover date. 相似文献
30.
Prof. Dr. Enrique J. Baran Irma L. Botto 《Monatshefte für Chemie / Chemical Monthly》1977,108(4):781-790
The infrared spectra of the title compounds, as well as that of the structurally related mineral meta-autunite, [Ca(UO2)2(PO4)2·n H2O], are reported and discussed using the available crystallographic data. The results can be considered as representative for the full group of the so-called torbernite-minerals. 相似文献