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31.
S. Padovani F. D'Acapito C. Sada E. Cattaruzza F. Gonella N. Argiolas M. Bazzan C. Maurizio P. Mazzoldi 《The European Physical Journal B - Condensed Matter and Complex Systems》2003,32(2):157-161
Lithium niobate crystals doped with erbium by the ion exchange process were studied by means of extended X-ray absorption
fine structure spectroscopy and secondary ion mass spectrometry. The study of the local atomic order allowed the determination
of the erbium environment in the crystal matrix and the investigation on the role of preparation conditions.
Received 21 November 2002 Published online 1st April 2003
RID="a"
ID="a"e-mail: sada@padova.infm.it 相似文献
32.
Cristina Padovani 《Journal of Elasticity》2000,58(3):257-268
An explicit expression of the derivative of the square root of a tensor is provided, by using the expressions of the derivatives
of the eigenvalues and eigenvectors of a symmetric tensor. Starting from this result, the derivatives of the right and left
stretch tensor U, V and of the rotation R with respect to the deformation gradient F, are calculated. Expressions for the material time derivatives of U, V and R are also given.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
33.
Danilo Stinghen Janaina G. Ferreira Giovana G. Nunes Jaísa F. Soares 《Acta Crystallographica. Section C, Structural Chemistry》2012,68(12):m353-m355
The pentanuclear title compound, [V5(C7H13O)10O5], has a metal–oxygen core that consists of five vanadyl(IV) centres bridged by the O atoms of cyclohexylmethanolate ligands. This particular ring topology is new to oxovanadium(IV) chemistry and resembles the structure proposed for [V5O15]5− on the basis of 51V NMR studies in aqueous solution. The bulky cyclohexylmethanolate ligands adopt chair‐like conformations and project outwards from the central cyclic core. The title compound crystallizes in a centrosymmetric triclinic unit cell, which contains four independent but chemically identical molecules in the asymmetric unit. The crystal structure is devoid of any significant intermolecular interactions. 相似文献
34.
Lucchesi Massimiliano Padovani Cristina Pasquinelli Giuseppe Zani Nicola 《Meccanica》1997,32(4):327-346
In this paper a constitutive equation for masonry arches is defined and its main properties are proven; in this equation to each pair of generalized strains (, ), with the extensional strain and the curvature change of the centre line, is assigned the pair of generalized internal forces (N,M), where N is the normal force and M the bending moment. Subsequently, the collapse of masonry arches is characterized and the static and kinematic theorems proven. Finally, a method for determining the collapse load in the case of circular arches subjected to their own weight and a vertical point load applied at a point of the extrados is presented. The results obtained, of interest in some applications, are summarized in a series of graphs. 相似文献
35.
M. Bonchio V. Conte F. Di Furia G. Modena C. Padovani M. Sivak 《Research on Chemical Intermediates》1989,12(2):111-124
The oxidation of di-n-butyl sulfide and phenylmethyl sulfide by two vanadium (V) peroxocomplexes, e.g. VO(O2)OCH3, 1, and VO(O2)(PIC)(H2O)2, 2, in methanol, was investigated. The kinetic analysis of the reactions revealed significant mechanistic differences between
the two peroxometal oxidants. In particular, 1 behaves as an electrophilic oxidant so that the transition state of sulfide
oxidations by 1 may be described as a S
N
2 displacement on the peroxide oxygen whereas 2 acts as a radical oxidant in a process which has a substantial SET character. The role of the picolinaoo ligand in determining the reactivtty of 2 is discussed in terms of a decrease of the electrophilicity of the peroxide oxygen compared with 1 and of a stabilization of the radical metal species. 相似文献
36.
37.
Martinez M Reis GS Pinheiro PF Almeida CC Cagnon VH Mello-Júnior W Pereira S Padovani CR Martinez FE 《Micron (Oxford, England : 1993)》2008,39(5):587-592
The effects of chronic alcohol ingestion on the structure of the glandular epithelium of the seminal vesicle of the rodent Calomys callosus were analyzed in 24 adult animals aged 3 months divided into three experimental groups. The control group received a solid diet and tap water, the alcoholic group received the same solid diet and ethanol P.A. diluted 20% in water (v/v) for 4 months. The abstinent group received the same liquid diet of the alcoholic one for the same period and after that the alcoholic diet was changed by water for a period of 3 months. After treatment, all animals were anesthetized, weighed and sacrificed. At the end of treatment, mean body weight did not differ between animal groups. The glandular epithelial cells of the alcoholic and abstinent groups showed atrophy and ultrastructural alterations such as the presence of altered nuclei, intense dilatation of the cisterns of the granular endoplasmic reticulum, intense digestive vacuoles and lipid droplets. Ethanol ingestion provokes marked lesions on the epithelium of the seminal vesicle probably interfering on the glandular secretion. 相似文献
38.
S. Padovani F. D'Acapito E. Cattaruzza A. De Lorenzi F. Gonella G. Mattei C. Maurizio P. Mazzoldi M. Montagna S. Ronchin C. Tosello M. Ferrari 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,25(1):11-17
Composite silica films containing metal nanoclusters were prepared by the rf- sputtering technique, in which SiO2 was co-deposited with gold+copper, gold+silver, or copper+silver. The formation of either pure or alloy clusters was studied
by extended X-ray absorption fine structure spectroscopy and transmission electron microscopy. For all systems, the presence
of alloy aggregates was evidenced. Moreover, small amounts of pure metal aggregates as well as dispersed or oxidized dopants
were observed.
61.46.+w Nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals – 61.10.Ht X-ray absorption spectroscopy:
EXAFS, NEXAFS, XANES, etc. – 81.05.Pj Glass-based composites, vitroceramics
Received 29 June 2001 相似文献
39.
A method is described for the determination of stable scandium in samples of plants, animals, sediments, soils, rocks and minerals. The samples and comparator standards were irradiated in a neutron flux of 5·1012 n/cm2/sec for 4 h and dissolved and the scandium quantitatively precipitated from 2N nitric acid as scandium phytate; contaminants were rinsed from the precipitate with nitric and hydrochloric acids. The limit of detection was 0.005μg(±10% at the 95% confidence level). The activated 46Sc was counted by γ-spectrometry. 相似文献
40.
Nanogram level quantitation of oxycodone in human plasma by capillary gas chromatography using nitrogen-phosphorus selective detection. 总被引:1,自引:0,他引:1
A sensitive and specific capillary gas chromatographic assay is reported for the quantitation of oxycodone in human plasma. The technique involves a single extraction of oxycodone and internal standard (hydrocodone) from plasma by toluene containing 1% isopropanol. Separation is achieved on a methyl silicone (HP-1) fused-silica capillary column (25 m x 0.2 mm I.D., 0.33 microns film thickness) and detection is by nitrogen-phosphorus selective mode. The minimum quantifiable limit is 1.8 ng/ml using 2 ml of plasma. The method is applicable to characterize the plasma profile of oxycodone in humans after a single oral 5-mg oxycodone hydrochloride tablet. 相似文献