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991.
992.
Alessandro Chiolerio Paolo Allia Edvige Celasco Paola Martino Federico Spizzo Federica Celegato 《Journal of magnetism and magnetic materials》2010,322(9-12):1409-1412
Patterned soft magnetic materials are eligible for use in magnetic random access memories. A hexagonal-lattice pattern of circular antidots was produced by optical lithography in a Co film. In order to test the effect of geometry on the local magnetisation configuration of such a structure, we performed room-temperature angle-resolved magnetisation measurements aimed to check the pinning of domain walls by the pattern's lattice. Magnetoresistance (MR) room-temperature measurements were performed at various angles between the magnetic field direction and the macroscopic electrical current vector, to clarify whether and how the local current density configuration affects the MR response. We found that the magnetoresistance is of anisotropic type (AMR) and has a local origin. Furthermore, the largely unsaturating behaviour of MR at high fields may be explained only by considering that tiny portions of the pattern constitute highly frustrated regions and align their magnetisation at rather high fields. A simplified model based on a local anisotropy term is shown to account for the experimental results for both M and MR. 相似文献
993.
We study purely nonlocal Hamiltonian structures for systems of hydrodynamic type. In the case of a semi-Hamiltonian system, we show that such structures are related to quadratic expansions of the diagonal metrics naturally associated with the system. 相似文献
994.
Massimo Peruffo Pablo Contreras-Carballada Paolo Bertoncello Ren M. Williams Luisa De Cola Patrick R. Unwin 《Electrochemistry communications》2009,11(10):1885-1887
A method for assembling Pt nanoparticles (5 nm diameter) on indium tin oxide (ITO) and highly oriented pyrolytic graphite (HOPG) electrodes, via the potential-assisted deposition of pre-formed perthiolated-β-cyclodextrin-capped Pt nanoparticles is described. Cyclic voltammetry allowed control over the surface coverage of monodisperse Pt nanoparticles in a simple fashion, as evidenced by the voltammetric response and atomic force microscopy of the resulting electrode surface. The Pt nanoparticle arrays formed in this way were electrocatalytically active towards proton reduction-hydrogen evolution. The methodology described thus opens up a new approach for the deposition of metal nanoparticles with controlled surface density for the investigation of electrocatalytic processes. 相似文献
995.
Angela Chambery Antimo Di Maro Carmen Sanges Valeria Severino Maura Tarantino Annalisa Lamberti Augusto Parente Paolo Arcari 《Analytical and bioanalytical chemistry》2009,395(7):2281-2291
Diagnostic techniques applied to the field of cultural heritage represent a very important aspect of scientific investigation.
Recently, proteomic approaches based on mass spectrometry coupled with traditional spectroscopic methods have been used for
painting analysis, generating promising results for binder’s protein identification. In the present work, an improved procedure
based on LC-ESI/Q-q-TOF tandem mass spectrometry for the identification of protein binders has been developed for the molecular
characterization of samples from an early-twentieth-century mural painting from the St. Dimitar Cathedral in Vidin, Bulgaria.
The proteomic investigation has led to the identification of both egg white and egg yolk proteins, according to traditional
old recipes for tempera paintings. In addition, beyond the egg components, the presence of caseins was also revealed, thus
suggesting the use of milk as binding medium, fixative or stabilising agent. Furthermore, for the first time, the capability
to discriminate the milk origin on the basis of alpha casein proteotypic peptides is reported, that are diagnostic for a given
species, thus opening interesting perspectives in art and archaeological fields. 相似文献
996.
Paolo Salvatore 《Journal of Pure and Applied Algebra》2009,213(2):224-230
We show that the operad Lie is free as a non-symmetric operad. Then we study the generating series counting the operadic generators. We find a recursive formula for the coefficients of the series and show that the asymptotic density of the operadic generators is 1/e. 相似文献
997.
Becucci L León RR Moncelli MR Rovero P Guidelli R 《Langmuir : the ACS journal of surfaces and colloids》2006,22(15):6644-6650
The channel-forming peptide melittin was incorporated into a biomimetic membrane consisting of a mercury electrode coated with a thiolipid monolayer, with a lipid monolayer self-assembled on top of it. The thiolipid consisted of a hydrophilic tetraethyleneoxy chain terminated at one end with a disulfide group, for anchoring to the mercury surface, and covalently linked at the other end to two diphytanyl chains, which formed a lipid bilayer with the overhanging lipid monolayer. The conductance of the lipid bilayer in contact with aqueous 0.1 M KCl was measured by electrochemical impedance spectroscopy over a frequency range from 1 x 10(-2) to 1 x 10(5) Hz and a potential range of 0.7 V for different compositions of the outer lipid monolayer. The conductance increases abruptly above the background level at sufficiently negative applied potentials, attaining a maximum value that increases with the composition of the outer monolayer in the order PC/chol (60:40) < PC < PC/SM/chol (59:15:26) < PS, with PC = phosphatidylcholine, chol = cholesterol, SM = sphingomyelin, and PS = phosphatidylserine. The higher the maximum conductance, the less negative the applied potential at which it is attained. This behavior is also discussed using a model of the electrified interphase. 相似文献
998.
The rotational supersonic jet Fourier transform microwave spectra of the 35Cl and 37Cl species of the molecular complex chlorofluoromethane-argon show that, in its equilibrium conformation, the argon atom is located out of the ClCF plane, interacting with the F and Cl atoms. All rotational transitions are split into several quadrupole components, each of them further split into two lines, due to the tunneling motion of the Ar atom between two equivalent positions, below and above the ClCF plane. The feasible low energy pathway between the structurally degenerate conformations is described, in a first approximation, by a circular motion around the C-Cl bond, with barriers estimated to be about 61 and 100 cm(-1). 相似文献
999.
Colantoni D Fioravanti S Pellacani L Tardella PA 《The Journal of organic chemistry》2006,71(16):6295-6297
CF3-enones showed a different reactivity in amination reactions with nosyloxycarbamates. 4-Oxazolines or vinyl carbamates were obtained as unique products depending on the nature of double-bond substituents and on the choice of carbamates and bases. Starting from trans-trifluoroacetyl olefins carrying a heterocyclic residue or the p-methoxyphenyl group on the double bond, a rare loss of CF3CO was observed when the aminations were performed under heterogeneous conditions using CaO as the base. 相似文献
1000.
Di Bussolo V Romano MR Favero L Pineschi M Crotti P 《The Journal of organic chemistry》2006,71(4):1696-1699
The reaction of the new D-galactal-derived allylic aziridine 1beta with O-nucleophiles (alcohols and monosaccharides) affords, in a high to complete beta-stereoselectivity, the corresponding 2,3-unsaturated-beta-O-glycosides bearing a beta-N-functionality at C4. 相似文献