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61.
Changes in the thermogravimetrically determined oxidation behaviors of CVD-grown multiwalled carbon nanotubes with varying synthesis conditions are examined. Catalyst type and synthesis temperature are found to have a measurable impact upon nanotube stability, suggesting differing levels of crystalline perfection in the resulting nanotubes. The results provide evidence showing the catalytic effects of nanotube catalyst particles and their oxides upon the oxidation of nanotube carbon and graphite. The significance of thermogravimetric analysis as a characterization tool for carbon nanotubes is discussed. 相似文献
62.
63.
Surface plasmon resonance imaging is used to demonstrate the recognition by the Ricinus communis agglutinin of a new SOD mimic, a bioconjugate of the manganese(II) complex of 1,4,7,10,13-pentaazacyclopentadecane with galactose. 相似文献
64.
M. Turco G. Bagnasco G Russo P. Ciambelli P. Patrono M. A. Massucci S. Vecchio 《Journal of Thermal Analysis and Calorimetry》1996,47(1):215-225
The ion exchange technique was employed for the preparation of VO2+ modified titanium phosphates as catalysts for the selective reduction of NO with NH3. The samples were prepared by contacting with a vanadyl sulphate solution different precursor materials, amorphous, crystalline or sodium half exchanged titanium phosphate. The vanadium contents of modified phosphates were in the range 0.08–2.3 wt%. XRD and thermal analysis TG/DTA showed that vanadium loading does not cause structural modification in hydrogen titanium phosphate. A vanadyl containing phase was obtained when half sodium titanium phosphate was employed. The NH3 TPD measurements indicated the presence of a wide distribution of NH3 adsorbing sites with medium-high strength. Catalytic activity measurements were performed under dilute conditions. It was found that the presence of vanadium even in low amounts strongly promote the catalytic activity. 相似文献
65.
A discrete time version for models of population dynamics in the presence of an infection 总被引:1,自引:0,他引:1
Giuseppe Izzo Antonia Vecchio 《Journal of Computational and Applied Mathematics》2007,210(1-2):210-221
We present a set of difference equations which represents the discrete counterpart of a large class of continuous model concerning the dynamics of an infection in an organism or in a host population. The limiting behavior of the discrete model is studied and a threshold parameter playing the role of the basic reproduction number is derived. 相似文献
66.
Cucinotta V Giuffrida A Maccarrone G Messina M Puglisi A Rizzarelli E Vecchio G 《Dalton transactions (Cambridge, England : 2003)》2005,(16):2731-2736
The bis-amino AB derivative of beta-cyclodextrin on the secondary rim was synthesised and spectroscopically characterised by different techniques. Its binary systems both with protons and copper(II) were thermodynamically characterised by pH-metric potentiometry. In addition the ternary systems with each of the enantiomers of tryptophan and alanine were investigated. A thermodynamic stereoselectivity was observed for the tryptophan enantiomers and this was exploited to separate them by capillary electrophoresis through a ligand exchange mechanism (LECE). LECE separation of racemates of phenylalanine and tyrosine was also obtained. 相似文献
67.
F. Rodante S. Vecchio G. Catalani M. Guidotti 《Journal of Thermal Analysis and Calorimetry》2000,60(2):605-622
The thermal behaviour of some commercial pesticides was studied by simultaneous TG/DSC measurements. Kinetic parameters, related
to solid-gas phase transition processes, were also carried out by using dynamic TG technique.
The kinetics were analysed by using Arrhenius, Satava and Harcourt-Esson equations. The choice of the mathematical expression
to insert in these equations was influenced by the shape of the TG plot and other thermal analysis signals. The compounds
studied undergo a fusion process followed by a single vaporization process. The latter is well represented by a diffusive
process (D1, D2 or D3). The variation of the activation energy values within the range of temperature where the vaporization processes occur was
calculated. The enthalpy values of vaporization were also evaluated by using the Clausius-Clapeyron equation.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
68.
Nonlinear regression of the basic kinetic equation was used to determine kinetic parameters of simple and complex decomposition processes related to some pesticides and pharmaceutical substances. The method for this calculation was carried out using a single TG curve. These values were compared with those obtained with model‐fitting and model‐free methods. Nonlinear regression method is able to define a single mechanism for compounds undergoing one or few steps of decomposition processes. For compounds that undergo many steps of decomposition processes, only the mechanisms of some of them can be hypothesized. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 611–622, 2003 相似文献
69.
Teresa Del Vecchio 《Rendiconti del Circolo Matematico di Palermo》1979,28(3):455-472
In this paper we establish some characterizations of functions which are derivable or approximately derivable almost everywhere with respect to another one supposed increasing. 相似文献
70.
By numerical computations on a chain of 10 particles with Lennard-Jones nearest neighbours interaction, evidence is given for the applicability of the microcanonical ensemble at not too low energies. 相似文献