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21.
22.
It is shown that there are differentiable manifolds which can be characterized only by the geometric and topological structure of their linear subspaces. More precisely, such a characterization is possible for Grassmann and C. Segre's product manifolds. The starting point of this investigation was a paper by J. Misfeld, G. Tallini and the author [10], the ideas in which were further developed in [15,16,17].Dedicated to Professor Giuseppe Tallini on his 60th birthday 相似文献
23.
I. Fragala E. Ciliberto R.D. Fischer G.R. Sienel P. Zanella 《Journal of organometallic chemistry》1976,120(1):C9-C12
The photoelectron spectra of some cyclopentadienyI derivatives of uranium(IV) and thorium(IV), namely (C5H5)3 ThCl, (C5H5)3 UCl, (C5 H4 CH3)3 ThCl, (C5 H4 CH3)3 UCl, (C5 H4 CH3)3 UBr and (C5 H4 CH3 )3 UBH4, are reported the metal 5f ionization has been detected in all the uranium derivative spectra and a simple molecular orbital scheme qualitatively accounts for the number and position of the observed low energy bands. 相似文献
24.
Souza Maria Aparecida Ribeiro Marcela Zanella Silva Daniel Pereira Pessoa Adalberto Vitolo Michele 《Applied biochemistry and biotechnology》2002,98(1-9):265-272
Hexokinase (HK) and glucose 6-phosphate dehydrogenase (G6PDH) are important enzymes used in biochemical studies and in analytical
methods. The stability of the enzymes can be affected by several variables, pH being one of them. The effect of pH on the
stability of HK and G6PDH was evaluated in this work. Baker’s yeast cells were suspended in 50 mM Tris-HCl buffer (pH 7.5) containing 5.0 mM MgCl2, and submitted to disruption by agitation with glass beads and in the presence of protease inhibitors. The cell-free
extract was obtained by centrifugation (2880g; 10 min), followed by dilution into the buffers: 0.1 M acetate-acetic acid (pH: 4.0, 4.5, 5.0, or 5.5), 0.1 M phosphate buffer (pH: 6.0, 6.5, or 7.0), and 0.1 M Tris-HCl buffer (pH: 7.5, 8.0, 8.5, 9.0 or 9.5). The residual activity of HK and G6PDH, expressed as μmol of NADPH formed
per min, were measured through a period of buffer-enzyme contact from 0 to 51 h at 4°C. It was observed that up to 4 h both
enzymes were stable in all buffers used. However, after 51 h HK was stable at pH 6.0 and 7.5, whereas G6PDH was stable at
pH 7.0, 9.5, and between 4.5 and 5.5. 相似文献
25.
Benedetta Ferrario Margherita Zanella 《Stochastic Processes and their Applications》2019,129(5):1568-1604
We consider the two dimensional Navier–Stokes equations in vorticity form with a stochastic forcing term given by a gaussian noise, white in time and colored in space. First, we prove existence and uniqueness of a weak (in the Walsh sense) solution process
and we show that, if the initial vorticity is continuous in space, then there exists a space–time continuous version of the solution. In addition we show that the solution (evaluated at fixed points in time and space) is locally differentiable in the Malliavin calculus sense and that its image law is absolutely continuous with respect to the Lebesgue measure on . 相似文献
26.
Zhao Yue Waqas Khalid Marco Zanella Azhar Zahoor Abbasi Andrea Pfreundt Pilar Rivera Gil Kirsten Schubert Fred Lisdat Wolfgang J. Parak 《Analytical and bioanalytical chemistry》2010,396(3):1095-1103
Gold electrodes with switchable conductance are created by coating the gold surface with different colloidal quantum dots.
For the quantum dot immobilization, a dithiol compound was used. By polarizing the electrode and applying a light pointer,
local photocurrents were generated. The performance of this setup was characterized for a variety of different nanoparticle
materials regarding drift and signal-to-noise ratio. We varied the following parameters: quantum dot materials and immobilization
protocol. The results indicate that the performance of the sensor strongly depends on how the quantum dots are bound to the
gold electrode. The best results were obtained by inclusion of an additional polyelectrolyte film, which had been fabricated
using layer-by-layer assembly.
相似文献
27.
I. Loris M. Bertero C. De Mol R. Zanella L. Zanni 《Applied and Computational Harmonic Analysis》2009,27(2):247-254
We propose a new gradient projection algorithm that compares favorably with the fastest algorithms available to date for ℓ1-constrained sparse recovery from noisy data, both in the compressed sensing and inverse problem frameworks. The method exploits a line-search along the feasible direction and an adaptive steplength selection based on recent strategies for the alternation of the well-known Barzilai–Borwein rules. The convergence of the proposed approach is discussed and a computational study on both well conditioned and ill-conditioned problems is carried out for performance evaluations in comparison with five other algorithms proposed in the literature. 相似文献
28.
Anthony Fucaloro Robert Pinnell Andrew Zanella Karen Conrad Yan Pu 《Journal of solution chemistry》2006,35(9):1245-1254
Both the partial molar volumes (V°
2m
refractions (R°
2m
) of the solutes at infinite dilution have been determined at 20 °C for a series of six octahedral N6-coordinated cobalt(III) species featuring five coordinated ammonia ligands along with a sixth N-coordinated organonitrile of increasing ligand size (from acetonitrile to sebaconitrile). The experimental values for V°
2m
are consistent with the relative sizes of the ligands but show larger values than those generated by computer modeling as the size of the cation increases, presumably due to the void space of the cation which increases with the size of the nitrile ligand. 相似文献
29.
M. Bolzan I. Bergenti G. Rossetto P. Zanella V. Dediu M. Natali 《Journal of magnetism and magnetic materials》2007
MnAs thin films were grown by metalorganic vapour-phase epitaxy (MOVPE) on GaAs(0 0 1), Si(0 0 1) and oxidised silicon substrates. All films are crystalline and contain only the ferromagnetic α-MnAs phase. X-ray diffraction (XRD) and atomic force microscopy (AFM) measurements show that films on GaAs(0 0 1) have strong preferential orientation, developing elongated grains parallel to [1 –1 0] GaAs while films on bare and oxidised Si are polycrystalline with irregular-shaped, randomly oriented grains. Magneto-optic Kerr effect (MOKE) measurements show good magnetic properties for films on GaAs, such as strong in-plane anisotropy and squareness of the hysteresis loop in the easy direction. A Curie temperature of 340 K, remarkably higher than the bulk material (315 K), was found for a 65 nm thick film on GaAs. Films grown on bare and oxidised silicon wafers had lower Curie temperature and were magnetically isotropic. 相似文献
30.