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31.
The development of diffusion creep (DC) accompanying superplastic deformation (SPD) of the highly doped nickel alloy ZhS6KP is studied based on an investigation of the redistribution of dispersed intragrain deposits of the phase of Ni3(Al, Ti). Deposit-free zones (DFZ) are formed in the alloy, held at the temperature of SPD and accompanying deformation at the grain boundaries. The contribution of DC to the deformation was determined from a comparative analysis of the width of the DFZ in the deformed and undeformed parts of the samples for different grain sizes and rates of DC taking into account diffusion accommodation. It was established that for the optimum rate of SPD the upper limit of the contribution of DC to deformation for 2-m grains does not exceed 11%. It is concluded, based on the distribution of DFZ, that the effect of DC accompanying SPD is determined by diffusion fluxes, associated with the local concentration of stress accompanying the development of grain-boundary slipping.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 40–45, June, 1986.In conclusion, we thank Yu. M. Mishin for a useful discussion of the results. 相似文献
32.
Optical frequency doubling of a single-mode cw Rhodamin 6G ring dye laser is performed with a thin angle-tuned LiIO3 Brewster cut crystal in a stabilized passive ring resonator. A conversion efficiency of =5 mW uv/320 mW fundamental input power was achieved at =603 nm. 相似文献
33.
Single Crystals of CoNbO4 with AlNbO4 Structure The hitherto unknown single crystals of CoNbO4 were prepared. CoNbO4 has AlNbO4 structure with monoclinic symmetry (space group C?C2/m; a = 1212.9; b = 374.9; c = 651.2 pm; β = 107.6°). X-ray investigations shows on ordered arrangement of Co3+ and Nb5+ with well defined differences in respect to oxocobaltates with Columbite type (CoNb2O6 = Co0.33NbO.66O2) and Rutil type (CoNbO4 = Co0.5-xNb0.5+xO2; 0 ? × ? 0.166) structure. 相似文献
34.
Studies of the complexes of pyridinecarboxylic acids with divalent metal ions as a function of the position of the carboxyl groups were extended. The thermal properties of the complexes of quinoline acid (pyridine-2,3-dicarboxylic acid) with several divalent metal ions were determined by thermogravimetry (TG) and differential thermal analysis (DTA). A correlation between these compounds and others obtained by reaction between the studied metal ions with similar acids (lutidinic acid (pyridine-2,4-dicarboxylic acid) and isocinchomeronic acid (pyridine-2,5-di-carboxylic acid) is discussed in terms of the position of the carboxyl group far from the aza group. The thermal stability of the metal complexes is in the order Mn(II) > Fe(II) > Zn(II) ? Co(II) > Ni(II) > Cu(II). 相似文献
35.
Conjugated esters and amides react with aryldiazonium salts at room temperature (MeCN) to form the corresponding iminium hydrazone derivatives, which can be thermally cyclized to cinnoline-3-esters and cinnoline-3-amides. In general the intermediate iminium salts derived from the enamine amides cyclize faster than those from the enamine esters. Furthermore, the ease of cyclization depends upon the structure of the base-component of the enamine ester or the amide and the substituent in the aryl moiety of the diazonium salt. The configurational structure of the iminium hydrazones, studied by NMR spectroscopy, has been shown to involve H-bonding of the hydrazonyl N-H with the ester or the amide CO group. 相似文献
36.
37.
U. Bohnstedt und R. Budenz 《Fresenius' Journal of Analytical Chemistry》1957,159(2):95-102
Zusammenfassung Die bei der Phosphorbestimmung bewährte einstufige Molybdänblaumethode erwies sich auch bei der Arsenbestimmung als sehr zuverlässig und erfordert kein besonders strenges Einhalten der Bedingungen.Zur Anwendung auf Eisen, Stahl und besonders auf Isolierungsrückstände wird der Aufschluß mit Salpetersäure-Perchlorsäure empfohlen. Da die gemeinsame Bestimmung von Phosphor und Arsen nach diesem Verfahren nur bei relativ hohen Arsengehalten (As>2·P) eine ausreichende Genauigkeit ergibt, wird das Arsen durch Destillation als Trichlorid abgetrennt. Destillation und Verarbeitung des Destillats werden ausführlich untersucht. Die Extinktion wird bei 900 m gemessen.Es wird eine vollständige Arbeitsvorschrift gegeben für 0,03–0,15 mg Arsen. Eine Bestimmung dauert etwa 45 min; bei Serienanalysen kann ein geübter Laborant 4–5 Bestimmungen je Stunde durchführen. Die Methode ist auf jedes Material anwendbar, das sich in dem Säuregemisch lösen läßt. 相似文献
38.
G. Menchi
S. Paganelli
U. Matteoli A. Scrivanti C. Botteghi 《Journal of organometallic chemistry》1993,450(1-2):229-235The unsaturated compounds 1,2-dicarbethoxy-1,2,3,6-tetrahydropyridazine 1 and 1,2-dicarbethoxy-1,2,3,4-tetrahydropyridazine 2 have been hydroformylated and hydrocarbethoxylated in the presence of some well known cobalt, rhodium, palladium and platinum catalysts. The hydroformylation reaction can be tuned by a suitable choice of the catalyst precursor and reaction conditions, thus allowing the synthesis with high selectivity of one of the two possible isomeric aldehydes. The carbonylation reaction is less synthetically useful, since it shows low activity and unsatisfactory chemo- and regio-selectivity. However, the ester 1,2,4-tricarbethoxyhexahydropyridazine 10 can be prepared in good yield from olefin 1 by using the complex [PdCl2(PPh3)2] as the catalyst precursor. 相似文献
39.
The proton NMR in single crystals of ferrocene has been studied by multiple pulse techniques at room temperature. In crystals of natural shape with plane faces the angular dependence of the resonance frequency due to the anisotropy of the shielding and due to the bulk susceptibility was found to be of about equal size, making analysis of the data practically impossible. By using a single crystal sphere the shape dependent part of the susceptibility contribution could be eliminated. In addition, the resolution obtained by the multiple pulse technique is considerably higher for spheres than for non-spherical crystals. As the ferrocene molecules rotate rapidly about their fivefold axes at room temperature, the shielding tensor σ must be axially symmetric. Having this in mind, the data could be analyzed to yield both the shielding tensor with Δσ = σ6 - σ⊥ = ?6.5 ± 0.1 ppm, σiso = ?4.2 ± 0.5 ppm from a spherical sample of TMS and the anisotropy of the susceptibility Δ x = 30 × 10?6 cgs units. 相似文献
40.
U. Gelius S. Svensson H. Siegbahn E. Basilier Å. Faxälv K. Siegbahn 《Chemical physics letters》1974,28(1):1-7
The line profile of the narrow, symmetric 1s line from neon, recorded with the new ESCA instrument with X-ray monochromatization, is analyzed. The natural linewidth of this line is found to be 0.23 ± 0.02 eV, in good agreement with theoretical calculations of the oscillator strengths for Auger transitions and X-ray emission. Spectra from molecules show frequently asymmetric core electron lines under high resolution. This rules out previous explanations based on a chemical influence on the natural lifetime. Contrary to earlier assumptions, vibrational excitations are shown to be important in core electron spectra. For methane, the vibrational energy spacing is large enough to allow the vibrational lines to be partly resolved. Recent results from accurate PNO CI calculations on methane agree well with the experimental findings. The Franck-Condon transitions in the C1s and N1s lines from CO and N2 are shown to be well described in the harmonic approximation and approximating the potential curves of the highly excited core hole states with the potential curve for the ground state of NO+, X1 Σ+. Knowledge of vibrational excitations in core electron spectra is shown to be valuable in the analysis of high resolution X-ray emission spectra of free molecules. 相似文献