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101.
This paper discusses the computation of real \(\mathtt {Z}\)-eigenvalues and \(\mathtt {H}\)-eigenvalues of nonsymmetric tensors. A generic nonsymmetric tensor has finitely many Z-eigenvalues, while there may be infinitely many ones for special tensors. The number of \(\mathtt {H}\)-eigenvalues is finite for all tensors. We propose Lasserre type semidefinite relaxation methods for computing such eigenvalues. For every tensor that has finitely many real \(\mathtt {Z}\)-eigenvalues, we can compute all of them; each of them can be computed by solving a finite sequence of semidefinite relaxations. For every tensor, we can compute all its real \(\mathtt {H}\)-eigenvalues; each of them can be computed by solving a finite sequence of semidefinite relaxations. 相似文献
102.
Nuvoli Daniele Alzari Valeria Sanna Roberta Scognamillo Sergio Alongi Jenny Malucelli Giulio Mariani Alberto 《Journal of nanoparticle research》2013,15(3):1-8
In this paper, GaN nanoparticles were synthesized from the complex Ga(H2NCONH2)6Cl3 in the flow of NH3 at a mild temperature (350 °C). Further purification was performed by the ethanol-thermal method. The ethanol-thermal method also prompted the GaN nanoparticles to grow into an anisotropic morphology. XRD patterns reveal that GaN nanoparticles have crystallized in a hexagonal wurtzite structure. TEM observation shows that the average size of the as-prepared nanoparticles is about 5–10 nm. The photoluminescence spectrum exhibits a broad green emission band with a peak at 510 nm. It can be known from the first-principle theoretic simulation by the TDDFT method that this fluorescence emission band is attributed to the hydride defects of V N-H on the surface of GaN nanoparticles. 相似文献
103.
We consider the mass-critical focusing nonlinear Schrödinger equation in the presence of an external potential, when the nonlinearity is inhomogeneous. We show that if the inhomogeneous factor in front of the nonlinearity is sufficiently flat at a critical point, then there exists a solution which blows up in finite time with the maximal (unstable) rate at this point. In the case where the critical point is a maximum, this solution has minimal mass among the blow-up solutions. As a corollary, we also obtain unstable blow-up solutions of the mass-critical Schrödinger equation on some surfaces. The proof is based on properties of the linearized operator around the ground state, and on a full use of the invariances of the equation with an homogeneous nonlinearity and no potential, via time-dependent modulations. 相似文献
104.
In this work, we studied the influence of time reaction and initiator amount on N-(1-naphthyl)acrylamide (NAM) polymerization, in dioxane and DMF. The same was done with three copolymers with methyl methacrylate (MMA). We found that NAM could be incorporated in high proportions in the copolymer. We also found that, with the same reaction time, the amount of benzoyl peroxide (BPO) has little or no effect on the polymerization degree; however reaction rates and yields were affected in DMF. All homopolymers showed a low dispersion (?), even when they were polymerized in solution. All DPNAMs can be classified as monodisperse. 相似文献
105.
Valeria Kagramanova Jutta Kunz Claus Lämmerzahl 《General Relativity and Gravitation》2008,40(6):1249-1278
Orbits of test particles and light rays are an important tool to study the properties of space-time metrics. Here we systematically
study the properties of the gravitational field of a globally regular magnetic monopole in terms of the geodesics of test
particles and light. The gravitational field depends on two dimensionless parameters, defined as ratios of the characteristic
mass scales present. For critical values of these parameters the resulting metric coefficients develop a singular behavior,
which has profound influence on the properties of the resulting space-time and which is clearly reflected in the orbits of
the test particles and light rays. 相似文献
106.
Valentina Noemi Madia Daniela De Vita Davide Ialongo Valeria Tudino Alessandro De Leo Luigi Scipione Roberto Di Santo Roberta Costi Antonella Messore 《Molecules (Basel, Switzerland)》2021,26(15)
Growing attention to environmental protection leads food industries to adopt a model of “circular economy” applying safe and sustainable technologies to recover, recycle and valorize by-products. Therefore, by-products become raw material for other industries. Tomato processing industry produces significant amounts of by-products, consisting of skins and seeds. Tomato skin is very rich in lycopene, and from its seeds, high nutritional oil can be extracted. Alternative use of the two fractions not only could cut disposal costs but also allow one to extract bioactive compounds and an oil with a high nutritional value. This review focused on the recent advance in extraction of lycopene, whose beneficial effects on health are widely recognized. 相似文献
107.
Maria Francesca Alberghina Patrizia Capizzi Salvatore Schiavone Silvestro Antonio Ruffolo Valeria Comite 《Natural product research》2019,33(7):1034-1039
AbstractStructural analysis of marble statues, carried out by non-invasive and in situ methods, is crucial to define the state of conservation of the artworks and to identify the deterioration phenomena that can affect them. In this work, we combined in situ non-destructive techniques, ultrasonic tomography (US), ultraviolet-induced visible fluorescence (UV-IF) and X-ray fluorescence (XRF) to study the bass-relief ‘Madonna con Bambino’ (Gorizia, Italy). The US revealed the presence of some metallic pivots, associated with areas of high sound velocity; moreover, a more degraded area has been identified in the lower part of the bass-relief. The acquired UV-IF image confirmed the presence of surface degradation, allowing a preliminary evaluation of the extension of a fracture, from surface to bulk. In addition, the different materials (both original and/or integrations) that compose the studied surface have been identified. The XRF has contributed to define the nature of the inorganic materials applied during undocumented previous restoration works on the surface as filler for lacunae. 相似文献
108.
Efficient sustainable V-catalyzed oxidative desulfurization of fuels assisted by ionic liquids 《燃料化学学报》2018,46(9):1121-1129
Fuel desulfurization is an appealing topic for the chemical industry since severe environmental regulations regarding SO2 emissions have been legislated in many countries. In order to reduce the amount of sulfur-containing compounds in fuels, responsible for high SOx emission levels, a green chemistry approach is compulsory. In this paper, vanadium salen and salophen complexes were used in the oxidation of a model aromatic sulfide, such as dibenzothiophene (DBT), in the presence of H2O2 as green oxidant. The oxidative process was successfully coupled with the extraction of the oxidized compounds by ionic liquids. The system resulted highly selective for sulfide oxidation, showing poor reactivity toward the oxidation of alkenes and allowing a significant reduction of S content in a model benzine. To note, the use of microwave in place of standard heating allowed to obtain 98% of DBT oxidation and almost complete sulfur extraction in the model fuel in 1000 s. For these reasons, this system was considered an easy, rapid and clean process to achieve fuel desulfurization. 相似文献
109.
We give necessary and sufficient conditions for the Kurzweil–Henstock integrability of functions given by , where xn belong to a Banach space and the sets (En)n are measurable and pairwise disjoint. Also weakly completely continuous operators between Banach spaces are characterized by means of scalarly Kurzweil–Henstock integrable functions. 相似文献
110.
Anharmonic behavior in the multisubunit protein apoferritin as revealed by quasi-elastic neutron scattering 总被引:1,自引:0,他引:1
Telling MT Neylon C Kilcoyne SH Arrighi V 《The journal of physical chemistry. B》2008,112(35):10873-10878
Quasi-elastic neutron scattering (QENS) has been used to study the deviation from Debye-law harmonic behavior in lyophilized and hydrated apoferritin, a naturally occurring, multisubunit protein. Whereas analysis of the measured mean squared displacement (msd) parameter reveals a hydration-dependent inflection above 240 K, characteristic of diffusive motion, a hydration-independent inflection is observed at 100 K. The mechanism responsible for this low-temperature anharmonic response is further investigated, via analysis of the elastic incoherent neutron scattering intensity, by applying models developed to describe side-group motion in glassy polymers. Our results suggest that the deviation from harmonic behavior is due to the onset of methyl group rotations which exhibit a broad distribution of activated processes ( E a,ave = 12.2 kJ.mol (-1), sigma = 5.0 kJ x mol (-1)). Our results are likened to those reported for other proteins. 相似文献