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291.
292.
The physico-chemical characteristics of manganese soaps (caproate, caprylate and caprate) in solid state were investigated by infrared (IR), x-ray diffraction, magnetic and TGA measurements. The IR results revealed that the fatty acids exist in dimeric state through hydrogen bonding and manganese soaps possess ionic character. The x-ray analysis showed that manganese soaps have single-layer structure with molecular axes slightly inclined to the basal plane. The magnetic results suggested the presence of five unpaired electrons with octahedral geometry and possesssp
3
d
2 hybridization. The thermal decomposition of these soaps is kinetically of zero order and the energy of activation for the decomposition process lies in the range 9.2–12.8 K Cal mol–1. 相似文献
293.
1. Oxidation ot tartronic acid has been studied and it has been shown that the oxidation of glycerol by ceric sulphate does not proceed via this acid by was presumed by earlier workers. 2. It has been shown that the oxidation of formic acid by pure ceric sulphate is negligible, but using chromium sulphate as catalyst, formic acid can be quantitatively oxidized. 3. Oxidation of glycol and glycerol can be carried out quantitatively either to the -formic acid stage or completely to carbon dioxide and water. A combination of the above provides a method for the estimation of the two compounds when present together in a mixture. 相似文献
294.
Frequency spectra of the complex permittivity for 1,2-dichloroethane–alcohol binary mixtures have been determined over the frequency range 10 MHz to 20 GHz at 15, 25, 35, and 45°C, using the time-domain reflectometry (TDR) technique, for 11 compositions of each 1,2 dichloroethane–alcohol system. The alcohols used in the study were methanol, ethanol, and 1-propanol. The relaxation in these systems can be described by a single relaxation time using the Debye model. The static dielectric constant, relaxation time, the corresponding excess dielectric properties, Kirkwood correlation factor, and Bruggeman factor of the mixtures have been determined. The static dielectric constants for the mixtures have been fitted with the modified Bruggeman model. 相似文献
295.
Castor oil has been transformed—via methyl ricinoleate—to PGF1α by strategy wherein 16 of the 18 carbons of the castor oil backbone are incorporated in the C-20 PGF1α, involving, inter alia, a novel procedure for the regiospecific functionalisation of terminal olefins, a novel degradation of aldehyde to lower acid and strategies useful for the generation of the highly functionalised prostanoid system, which specially illustrate the utility of MEM protecting group in diverse types of chemical transformations. Additionally, this work describes the preparation of synthons having potential utility and the synthesis of novel homo—PGP1α. 相似文献
296.
Tetraisopropoxyaluminate of copper undergoes alcoholysis reactions with various alcohols and acetylacetone to yield Cu[Al(OR)4]2, where RO = methoxy, ethoxy, 2,2,2-trifluoroethoxy, 2,2,2-trichloroethoxy, 1,3,-dibromo-2-propoxy, n-butoxy, teriary butoxy and pentoxy amyl and acetylacetone. Various physico-chemical studies like infrared, visible reflectance, and electron spin resonance and magnetic susceptibility measurements as well as molecular weight and elemental analysis have been made to throw light on the structural features of these derivatives. These studies suggest an octahedral environment for copper(II) in these derivatives. 相似文献
297.
Tris(alkylenedithiophosphates) of arsenic(III), antimony(III) and bismuth(III), have been synthesized by the reactions of alkylenedithiophosphoric acids with metal oxides and chlorides and of their ammonium salts with metal chlorides in suitable solvents. Mixed chloride alkylenedithiophosphates of arsenic(III) and antimony(III), have been obtained by the reactions of metal chlorides with ammonium alkylenedithiophosphates at 1 : 1 and 1 : 2 molar ratios or alternatively by the co-disproportionations reactions of metal chlorides with metal tris(alkylenedithiophosphates) at different (2 : 1 and 1 : 2) molar ratios. These new compounds have been characterized by elemental analyses, molecular weight measurements and spectroscopic (IR, and 1H and 31P NMR) data. Chelated structures with bidentate alkylenedithiophosphate groups have been proposed for all these derivatives. 相似文献
298.
Prem K. Mehrotra Jayaraman Chandrasekhar Periakaruppan T. Manoharan Sankaran Subramanian 《Theoretical chemistry accounts》1976,41(3):243-256
The Roby version of the NDDO MO method has been analysed by performing extensive calculations on several molecular systems employing a minimum basis set of STO-3G functions. The effect of using uniform scale factors and those derived from theS-expansion technique, for electron repulsion integrals has also been studied. At the all-electron level, the method, with all its refinements, does not appear promising. The all-valence NDDO MO method after correction byS-expansion, however, yields results which are in good agreement withab initio results. The performance of this scheme is comparable to that of the simplifiedab initio method of Brown and Roby. 相似文献
299.
Summary Equimolar adducts of mononuclear oxomolybdenum(IV)O,O-dialkyl and alkylene dithiophosphates with heterocyclic amines, MoO[S2P(OR)2]2·L (where when R=Et,i-Bu; L=pyridine and when R=Et,n-Pr,i-Bu; L=2,2-bipyridyl, 1,10-phenanthroline) and (where G=CH2CMe2CH2, L=2,2-bipyridyl and when G=CMe2CMe2; L=pyridine) have been prepared by reacting the corresponding oxomolybdenum(IV) complexes with an excess of pyridine or with bipyridyl or phenanthroline in a 11 molar ratio.The complexes have been characterized by elemental analyses and molecular weight determinations. Their probable structures are proposed on the basis of i.r. and n.m.r. (1H,13C and31P) spectral data, which are consistent with a 6-coordinated octahedral structure for all the base adduct complexes. 相似文献
300.
Summary The above estimations show that stannous chloride and uranyl acetate can be estimated with the help of chromous sulphate. In the case of tin, excess of ferric iron is added and its excess found by titration with chromous sulphate, using neutral red or phenosafranine as indicator. In the case of uranyl acetate chromous salt titration, the above two indicators work satisfactorily in the absence of excess of sulphuric acid, whereas methyl red and p-ethoxycrysodine give good end points even in the presence of excess acid. In the alternative procedure for estimation of uranium, chromous sulphate serves the purpose of a Jone's reductor.Ammonium metavanadate solution can be titrated directly against chromous sulphate. N-phenylanthranilic acid, diphenylamine, diphenylbenzidine and diphenylamine sulphonic acid serve satisfactorily as internal indicators for the VO3– to VO2+ change. It has been shown that ferric and cupric salts do not interfere in the above titrations. Mixtures of vanadate and dichromate or vanadate and ceric sulphate can also be titrated in the same manner using the same indicators.Part VI: cf. Z. analyt. Chem. 162, 33 (1958). 相似文献