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41.
Aldo Portela 《Bulletin of the Brazilian Mathematical Society》2009,40(1):53-75
It is known that not every Cantor set of S
1 is C
1-minimal. In this work we prove that every member of a subfamily of what we here call regular interval Cantor set is not C
1-minimal. We also prove that no member of a class of Cantor sets that includes this subfamily is C
1+∈-minimal, for any ∈ > 0.
Partially supported by CNPq-Brasil and PEDECIBA-Uruguay. 相似文献
42.
Summary Solution existence, uniqueness and regularity are analyzed for the elastic plate on unilateral elastic foundation problem. Some results are also given for the one-sided rigid foundation case.
Sommario Si studiano l'esistenza, l'unicità e la regolarità delle soluzioni del problema della piastra elastica su fondazione elastica unilaterale. Sono anche dati alcuni risultati per il caso di fondazione rigida unilaterale.相似文献
43.
44.
Silvia Rita Amato Aviva Burnstock Maureen Cross Koen Janssens Francesca Rosi Laura Cartechini Raffaella Fontana Alice Dal Fovo Marco Paolantoni Chiara Grazia Aldo Romani Anne Michelin Christine Andraud Aurélie Tournié Joris Dik 《X射线光谱测定》2019,48(4):282-292
The paintings by Édouard Manet in The Courtauld Gallery Déjeuner sur l'herbe (1863–68), Marguerite de Conflans en Toilette de Bal (1870–1880), Banks of the Seine at Argenteuil (1874), and A Bar at the Folies–Bergère (1882) were investigated for the first time using a range of non-invasive in situ analyses. The aims of the study were to investigate the painting techniques and materials used for this group of works and to critically evaluate the technical evidence derived from the integrated use of imaging techniques and portable spectroscopic methods in this context. The paintings were investigated by means of macro X-ray fluorescence (MA-XRF), reflection spectral imaging, portable UV–Vis–NIR spectroscopy, portable Raman spectroscopy, and reflection FTIR. MA-XRF and reflection spectral imaging allowed visualising elements in the compositions that were not visible using traditional methods of technical study. For example, MA-XRF analysis of Déjeuner sur l'herbe revealed elements of the development of the composition that provided new evidence to consider its relationship to other versions of the composition. The study also highlighted questions about the interpretation of elemental distribution maps and spectral images that did not correspond to the reworking visible in X-radiographs. For example, in A Bar at the Folies–Bergère Manet made numerous changes during painting, which were not clearly visualised with any of the techniques used. The research has wider implications for the study of Impressionist paintings, as the results will support technical studies of works by other artists of the period who used similar materials and painting methods. 相似文献
45.
A general method is presented to explicitly compute autocovariance functions for non-Poisson dichotomous noise based on renewal theory. The method is specialized to a random telegraph signal of Mittag-Leffler type. Analytical predictions are compared to Monte Carlo simulations. Non-Poisson dichotomous noise is non-stationary and standard spectral methods fail to describe it properly as they assume stationarity. 相似文献
46.
Weak steady Mach reflections are numerically simulated using unstructured grids by means of either “shock-fitting” or “shock-capturing”
techniques. It is shown that shock-fitting allows using coarser meshes than those required by shock-capturing, since the latter
needs mesh refinement in the direction normal to the discontinuities, which is not needed using the former approach. The shock-fitted
solution is also free from the numerical disturbances that arise along the captured discontinuities and pollute the captured
solution in the smooth flowfield region. Finally, the shock-fitting solutions show the presence of a small region next to
the Mach stem and the reflected shock downstream of the triple point, characterized by very high gradients. 相似文献
47.
We exhibit a class of integer spin systems whose free energy can be written in term of an absolutely convergent series at
any temperature. This class includes spin systems on ℤ
d
interacting through infinite range pair potential polynomially decaying at large distances r at a rate 1/r
d+ε
with ε>0. It also contains the Blume-Emery-Griffiths model in the disordered phase at large values of the crystal field. 相似文献
48.
A simple spray pyrolysis setup is used to grow multi-walled carbon nanotubes (MWCNTs), from a ferrocene solution in benzene
as precursor. The effects of process variables such as growth temperature, position of the aerosol generator and position
in the reactor where the sample was formed were investigated. These variables have a strong influence on the graphitization
degree, homogeneity, diameter and alignment of the nanotubes, as observed by TEM, SEM, XRD and Raman spectroscopy. Vertically
aligned MWCNT arrays with high density were obtained in large areas (10 × 10 mm2), with high yield (2.1 mg cm−2) and at a growth rate at 1.43 μm min−1, by a suitable choice of the experimental conditions. 相似文献
49.
Valerio Zardetto Thomas M. Brown Andrea Reale Aldo Di Carlo 《Journal of Polymer Science.Polymer Physics》2011,49(9):638-648
Designing and developing flexible electronics requires a thorough investigation of the substrates available for the fabrication of devices. Here, we present a practical study on a variety of significant substrates: polyethylene terephthalate (PET), its heat‐stabilized (HS) derivative, HS‐PET, and polyethylene naphthalate (PEN) plastic insulating films; indium tin oxide (ITO)‐coated ITO/PEN and ITO/PET transparent conducting films; rigid ITO/glass and FTO/glass substrates; stainless steel and titanium foils. We put the substrates through a range of tests these actually undergo during device fabrication to determine their optical, mechanical flexibility (under different types of tensile and compressive stress bending with and without a PEDOT:PSS conducting polymer layer), solvent resistance, stability to temperature treatment (conductivity and deformation), and to UV irradiation. We highlight issues and propose solutions to improve substrate response. The results and thresholds extracted reveal limitations and windows of opportunity useful for the designer of flexible optoelectronics in determining manufacturing processes and the final applications under everyday operation. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
50.
Umberto Costantino Maria Antonietta Massucci Aldo La Ginestra Anna Maria Tarola Laura Zampa 《Journal of inclusion phenomena and macrocyclic chemistry》1986,4(2):147-162
The intercalation of imidazole and some organic species containing the imidazole ring, between the layers of crystalline zirconium phosphate has been investigated. Fourteen new, well-ordered intercalation compounds are obtained with the batch procedure at r.t. and/or 60°C. A mechanism of formation of the various compounds is proposed on the basis of the interaction between the guest molecules (with their dimensions and geometries) and the free PO3OH groups available between the layers of the host. The new phases have been characterized by TG and X-ray methods. 相似文献