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61.
Edoardo Ballico 《Results in Mathematics》2007,50(3-4):169-172
Fix non-negative integers r, e, m, g, s such that r ≥ 3, 0 ≤ m < r, e > 0, g + s ≤ er + max{0, m − 1} + 2, g ≤ (e − 1)r + max{0,m − 1} and 0 ≤ s ≤ er + 2. Set d := er + m. Fix any such that and S is in linearly general position. Fix an ordering of the points P
1, . . . , P
s
of S. Here we prove the existence of an irreducible family Γ of smooth, non-degenerate and connected curves with degree d and genus g, all of them containing S and such that the induced map is dominant.
Received: September 19, 2006. 相似文献
62.
Romain Valentin Raluca Horga Barbara Bonelli Edoardo Garrone Francesco Di Renzo Françoise Quignard 《Macromolecular Symposia》2005,230(1):71-77
Supercritical drying of alginate gels is an efficient way to prepare aerogels with high surface area (>300 m2 · g−1). FTIR spectroscopy allows to monitor the adsorption of NH3 from the gas phase onto the acid sites of the alginate. Free carboxylic groups are effective Brønsted sites, whereas the divalent cations used in the ionotropic gelation present the properties of Lewis sites. The ratio between Brønsted and Lewis sites provides infomation on the role of pH in alginate gelation and suggests that non-buffered gelation by transition-metal cations is a mixed ionotropic-acid process. 相似文献
63.
64.
Edoardo Artioli Paolo Bisegna 《International Journal of Solids and Structures》2013,50(7-8):1154-1163
This paper presents a homogenization method for unidirectional periodic composite materials reinforced by circular fibres with functionally graded coating layers. The asymptotic homogenization method is adopted, and the relevant cell problem is addressed. Periodicity is enforced by resorting to the theory of Weierstrass elliptic functions. The equilibrium equation in the coating domain is solved in closed form by applying the theory of hypergeometric functions, for different choices of grading profiles. The effectiveness of the present analytical procedure is proved by convergence analysis and comparison with finite element solutions. The influence of microgeometry and grading parameters on the shear stress concentration at the coating/matrix interface is addressed, aimed at the composite optimization in regards to fatigue and debonding phenomena. 相似文献
65.
Pierpaolo Mastrolia Edoardo Mirabella Giovanni Ossola Tiziano Peraro 《Physics letters. [Part B]》2012
We show that the evaluation of scattering amplitudes can be formulated as a problem of multivariate polynomial division, with the components of the integration-momenta as indeterminates. We present a recurrence relation which, independently of the number of loops, leads to the multi-particle pole decomposition of the integrands of the scattering amplitudes. The recursive algorithm is based on the weak Nullstellensatz theorem and on the division modulo the Gröbner basis associated to all possible multi-particle cuts. We apply it to dimensionally regulated one-loop amplitudes, recovering the well-known integrand-decomposition formula. Finally, we focus on the maximum-cut, defined as a system of on-shell conditions constraining the components of all the integration-momenta. By means of the Finiteness Theorem and of the Shape Lemma, we prove that the residue at the maximum-cut is parametrized by a number of coefficients equal to the number of solutions of the cut itself. 相似文献
66.
67.
68.
Zanarini S Vankova S Hernandez S Ijeri VS Armandi M Garrone E Bonelli B Onida B Spinelli P 《Chemical communications (Cambridge, England)》2012,48(46):5754-5756
We report the first use of cobalt aluminophosphate (CoAPO5) as a water oxidation catalyst. A decrease in the overvoltage by about 0.2 V with respect to catalyst free FTO has been observed. Additionally, we show that CoAPO5, deposited on ITO or Pt, can also act as a photo-electro-catalyst, as it generates enhanced oxidation currents in the presence of light starting from a bias of +0.8 V vs. Ag/AgCl. 相似文献
69.
Edoardo Magnone Jong Pyo Kim Jung Hoon Park 《Journal of Thermal Analysis and Calorimetry》2012,110(2):755-764
In this study, the formation and characteristics of Sr-doped praseodymium alkaline-earth cobalt oxide were studied as a function of the strontium content (x). PrBa1?x Sr x Co2O5+d ceramics with x?=?0.0, 1/16, 1/8, 1/4, and 1/2.5 were prepared by solid-state reaction method from Pr6O11, BaCO3, SrCO3, and Co3O4. The solid-state reaction mechanisms were analyzed by differential thermal analysis (DTA) and thermogravimetry (TG) techniques to characterize properly the distinct thermal events occurring during synthesis of layered perovskite-type PrBa1?x Sr x Co2O5+d oxides. The X-ray diffraction (XRD) results were used to assist the interpretation of DTA?CTG analyses. The TG, DTA, and XRD results for the mixtures showed that the solid-state reaction between precursors was completed in a temperature range between 800 and 1000?°C. The strong influence of strontium contents (x) on the solid-state reaction temperatures and PrBa1?x Sr x Co2O5+d structure was found. 相似文献
70.
K Bhaskaran-Nair J Brabec E Aprà HJ van Dam J Pittner K Kowalski 《The Journal of chemical physics》2012,137(9):094112
In this paper we discuss the performance of the non-iterative state-specific multireference coupled cluster (SS-MRCC) methods accounting for the effect of triply excited cluster amplitudes. The corrections to the Brillouin-Wigner and Mukherjee's MRCC models based on the manifold of singly and doubly excited cluster amplitudes (BW-MRCCSD and Mk-MRCCSD, respectively) are tested and compared with exact full configuration interaction results for small systems (H(2)O, N(2), and Be(3)). For the larger systems (naphthyne isomers) the BW-MRCC and Mk-MRCC methods with iterative singles, doubles, and non-iterative triples (BW-MRCCSD(T) and Mk-MRCCSD(T)) are compared against the results obtained with single reference coupled cluster methods. We also report on the parallel performance of the non-iterative implementations based on the use of processor groups. 相似文献