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131.
Ricci AM Tognalli N de la Llave E Vericat C Méndez De Leo LP Williams FJ Scherlis D Salvarezza R Calvo EJ 《Physical chemistry chemical physics : PCCP》2011,13(12):5336-5345
Osmium pyridine-bipyridine redox centers have been tethered to Au electrodes by chemical modification through Au-S and Au-C bonds respectively. 4-Mercapto benzoic acid and the reduction product of the aryl diazonium salt of 4-amino benzoic acid were reacted on Au surfaces, with further post-functionalization by chemical reaction of the osmium complex amino-pyridine derivative with the surface carboxylates. The resulting modified Au surfaces were characterized by polarization modulated infrared reflection absorption spectroscopy (PM-IRRAS), scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy (XPS), resonant raman spectroscopy and cyclic voltammetry. 相似文献
132.
Bäcklund transformations are applied to study the Gross–Pitaevskii equation. Supported by previous results, a class of Bäcklund transformations admitted by this equation are constructed. Schwarzian derivative as well as its invariance properties turn out to represent a key tool in the present investigation. Examples and explicit solutions of the Gross–Pitaevskii equation are obtained.
相似文献133.
We prove that the fields of asymptotic lines of a real hyperbolic homogeneous polynomial are isotopic to the corresponding fields of its hyperbolic homogeneous part. We also show some combinatorial identities which are related to such isotopy. 相似文献
134.
Fernando De Tern Bruno Iannazzo Federico Poloni Leonardo Robol 《Numerical Linear Algebra with Applications》2019,26(5)
We consider the uniqueness of solution (i.e., nonsingularity) of systems of r generalized Sylvester and ?‐Sylvester equations with n×n coefficients. After several reductions, we show that it is sufficient to analyze periodic systems having, at most, one generalized ?‐Sylvester equation. We provide characterizations for the nonsingularity in terms of spectral properties of either matrix pencils or formal matrix products, both constructed from the coefficients of the system. The proposed approach uses the periodic Schur decomposition and leads to a backward stable O(n3r) algorithm for computing the (unique) solution. 相似文献
135.
César Massri Ariel Molinuevo Federico Quallbrunn 《Journal of Pure and Applied Algebra》2021,225(6):106630
Let ω be a differential q-form defining a foliation of codimension q in a projective variety. In this article we study the singular locus of ω in various settings. We relate a certain type of singularities, which we name persistent, with the unfoldings of ω, generalizing previous work done on foliations of codimension 1 in projective space. We also relate the absence of persistent singularities with the existence of a connection in the sheaf of 1-forms defining the foliation. 相似文献
136.
One-pot catalytic synthesis of butyrolactones from alkynols under mild conditions is described here. The methodology involves the use of the K2[Ni(CN)4]/NaBH4 system in presence of KCN and water. According to the experimental evidences, a possible mechanism pathway is suggested, which involves the nickel-catalyzed reductive cyanation of alkynol, followed by nitrile hydration, reduction of double bond and lactonization. 相似文献
137.
A so-called “interaction-box” formalism, which has recently been introduced to describe hysteresis in dynamical systems in the case of higher harmonic generation, is further discussed and generalized to describe the phenomenon of subharmonic generation. In this case, the increase in the periodicity of the response is reflected in the formation of multiple loops in the Effect (output) vs. Cause (input) diagrams. Conversely, we show how this type of response represents a sort of “signature” of the system, and can thus be employed to draw general conclusions about the features of the latter. A specific example of a nonlinear system is chosen to illustrate the approach, namely a vibrating cantilever beam with a breathing crack. Effect vs. Cause curves are calculated for this system in the presence of higher harmonics and subharmonics. 相似文献
138.
139.
The negative charge state of the vacancy-oxygen pair (Si-B1) in irradiated silicon was populated by illumination with polarized light, from which the direction of the electric dipole moment was determined to be near 〈110〉 perpendicular to the (Si-O-Si) bond axis. Energy dependence of the alignment suggests the presence of an optical absorption band at λ = 1.30 μm. 相似文献
140.
Bruno Danieli Federico Maria Rubino Alfredo Cremonesi 《Journal of mass spectrometry : JMS》1989,24(4):225-229
The positive fast atom bombardment (FAB) mass spectra of 15 N-carbobenzyloxy derivatives of α-amino acids are presented together with those of some synthetic peptides containing other widely employed protecting groups. The data obtained allow a fragmentation pattern to be established for the N-carbobenzyloxy moiety and to obtain detailed structural information on the main fragment ions. A study of the ion current ratio vs. time pattern shows that important fragments derive from the parent protonated molecule through FAB-induced condensed-phase reactions. 相似文献