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121.
122.
Gordana S. Risti? Milan S. Trtica Nebojša ?. Rom?evi? 《Applied Surface Science》2007,253(12):5233-5239
Diamond coatings were deposited by synergy of the hot filament CVD method and the pulse TEA CO2 laser, in spectroactive and spectroinactive diamond precursor atmospheres. Resulting diamond coatings are interpreted relying on evidence of scanning electron microscopy as well as microRaman spectroscopy. Thermal synergy component (hot filament) possesses an activating agent for diamond deposition, and contributes significantly to quality and extent of diamond deposition. Laser synergy component comprises a solid surface modification as well as the spectroactive gaseous atmosphere modification. Surface modification consists in changes of the diamond coating being deposited and, at the same time, in changes of the substrate surface structure. Laser modification of the spectroactive diamond precursor atmosphere means specific consumption of the precursor, which enables to skip the deposition on a defined substrate location. The resulting process of diamond coating elimination from certain, desired locations using the CO2 laser might contribute to tailoring diamond coatings for particular applications. Additionally, the substrate laser modification could be optimized by choice of a proper spectroactive precursor concentration, or by a laser radiation multiple pass through an absorbing medium. 相似文献
123.
B. Todorovi?-Markovi? I. Dragani? N. Rom?evi? M. Drami?anin 《Applied Surface Science》2007,253(8):4029-4035
In this paper, results of structural modification of fullerene thin films by single and multiple charged boron ions (B+, B3+) are presented. The applied ion energies were in the range of 15-45 keV. The characterization of as-deposited and irradiated specimens has been performed by atomic force microscopy, Raman and Fourier transform infrared spectroscopy and UV/vis spectrophotometry. The results of Raman analysis have shown the formation of amorphous layer after irradiation of fullerene thin films. Fourier transform infrared spectroscopy has confirmed the formation of new B-C bonds in irradiated films at higher fluences (2 × 1016 cm−2). The morphology of bombarded films has been changed significantly. The optical band gap was found to be reduced from 1.7 to 1.06 eV for irradiated films by B3+ ions and 0.7 eV for irradiated films by B+ ions. 相似文献
124.
125.
García-Couceiro U Olea D Castillo O Luque A Román P de Pablo PJ Gómez-Herrero J Zamora F 《Inorganic chemistry》2005,44(23):8343-8348
The compound [Mn(mu-ox)(4atr)2]n (1) (ox = oxalato and 4atr = 4-amine-1,2,4-triazole) has been synthesized and characterized by FT-IR spectroscopy, thermal analysis, variable-temperature magnetic measurements, and X-ray single-crystal diffraction methods. The crystal structure of compound 1 consists of one-dimensional linear chains in which trans-[Mn(4atr)2]2+ units are sequentially bridged by centrosymmetric bis-bidentate oxalato ligands. Cryomagnetic measurements show an overall antiferromagnetic behavior of the compound. Isolated chains of this polymer have been obtained by sonication of 1 in ethanol or treatment of the polymer with NaOH and morphologically characterized on highly oriented pyrolitic graphite and mica surfaces by atomic force microscopy and scanning tunneling microscopy. The procedures employed to obtain single chains of this coordination polymer open a route for future nanotechnological applications of these types of materials. 相似文献
126.
A new method is reported for determining the composition of complexes of the form AmBn; it can be used to differentiate mono- and polynuclear complexes. The method is based on that of Holme and Langmyhr. Good results were obtained for several complexes. 相似文献
127.
Pazo-Llorente R Rodriguez-Menacho MA González-Romero E Bravo-Díaz C 《Journal of colloid and interface science》2002,248(1):169-175
The effects of a sodium dodecyl sulfate, SDS, micellar solution on the coupling rates of two arenediazonium ions, ArN(2)(+), with the hydrophobic 1-naphthylamine, 1NA and N-(1-naphthyl) ethylenediamine, NED, coupling agents and with the hydrophilic Na salt of 2-naphthol-6-sulfonic acid, 2N6S, have been studied. First, we explored the micellar effects on the thermal decomposition of the arenediazonium ions. The observed rate constants are slightly depressed or increased, depending on the nature of ArN(2)(+), compared to those in pure water upon increasing [SDS]. Estimations of the corresponding association constant to the micelle indicate that a significant fraction of the arenediazonium ions are incorporated into the micelles even at low surfactant concentrations. The sulfonate group in 2N6S prevents its incorporation into the micellar aggregate due to the electrostatic barrier imposed by the micelles and, in consequence, the coupling reaction is inhibited. In contrast, when employing the naphthylamine derivatives, the observed rate constant increase rapidly up to a maximum at [SDS]=0.01 M and then decreases smoothly due to the dilution effect exerted by the micelles. The results are discussed in terms of the distribution of reactants between the micellar and aqueous pseudophases, the micellar-induced shift in the pK(a) of the amines, and the concentration/dilution effect exerted by the micelles. 相似文献
128.
M. Petrović N. Romčević M. Romčević G. Stanišić D. Vasiljević-Radović J. Trajić Z. Lazarević S. Kostić 《Journal of Crystal Growth》2012,338(1):75-79
New semimagnetic semiconductor Hg0.91Mn0.09Te-MnSe mixture, grown by Bridgman method, was investigate by Atomic Force Microscopy, X-ray and far-infrared spectroscopy, in order to obtain the necessary feedback information to determine the optimal conditions for crystal growth. The investigated mixture consists of MnSe nanoclasters randomly distributed in Hg0.91Mn0.09Te matrix. Far-infrared reflectivity spectrum of the Hg0.91Mn0.09Te-MnSe mixture was measured in the 80–500 cm?1 range at a room temperature. The analysis of the far-infrared spectrum was made by the fitting procedure. The Maxwell-Garnett effective medium theory is used for modeling an effective dielectric function, and on that way calculating both electron and phonon response. 相似文献
129.
130.
Vladimir Skarka Marina M. Lekić Aleksander G. Kovačević Boban Zarkov Nebojša Ž. Romčević 《Optical and Quantum Electronics》2018,50(1):37
We present here the experimental, theoretical, and numerical investigations of Kerr solitons generated by self-organization in black and yellow high quality bismuth germanium oxide (Bi12GeO20) single crystals. A picosecond laser beam of increasing power induces competing cubic and quintic nonlinearities. The numerical evolution of two-dimensional complex cubic-quintic nonlinear Schrödinger equation with measured values of nonlinearities shows the compensation of diffraction by competing cubic and quintic nonlinearities of opposite sign, i.e., the self-generation and stable propagation of solitons. Experiments as well as numerical simulations show higher nonlinearity in the black Bi12GeO20 than in the more transparent yellow one. 相似文献