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41.
Summary A method for interpolating between the (F)HNC and (F)PY approaches in order to take into account elementary contributions
has been presented in two preceding papers concerned with the properties of zero-temperature quantum fluids, described by
short-range correlated wave functions. In the present paper, both for Bose and for Fermi systems, the technique is extended
to the case in which the two-body radial distribution function contains a long-range tail, going asr
−4. The results obtained for the energy per particle and momentum distribution of liquid4He, polarized hydrogen and3He are presented in correspondence to variational wave functions containing only two-particle correlations.
Riassunto In due precedenti lavori è stata sviluppata una tecnica di interpolazione tra le approssimazioni (F)HNC e (F)PY per tenere conto dei cosiddetti contributi elementari nel calcolo delle proprietà dei fluidi quantistici a temperatura zero e descritti da funzioni d’onda con fattori di correlazione a corto raggio. Nel presente lavoro il metodo è esteso, per sistemi sia bosonici che fermionici, al caso in cui la funzione radiale di distribuzione contenga una coda con andamentor −4. Sono presentati i risultati ottenuti per l’energia per particella e la distribuzione di quantità di moto dell’4He liquido, dell’idrogeno polarizzato e dell’3He liquido, in corrispondenza a funzioni d’onda variazionali contenenti solo correlazioni di coppia.
Резюме В двух предыдущих работах был предложен метод интерполяции между (F)HNC и (F)PY подходами. В этих работах рассматривались свойства квантовых жидкостей при нулевой температуре, которые описываются волновыми функциями с короткодействующими корреляциями. В данной работе, для Бозеи Ферми-систем, предложенная тенхика обобщается на случай, когда двух-частичная радиальная функция распределения содержит длиннодействующий хвост, который спадает какr −4. Приводятся результаты для энергии на одну частицу и импульсное распределение для жидкого4He, поляризованного водорода и3H, причем соответствующие вариационные волновые функции содержат только двух-частичные корреляции.相似文献
42.
We study the Riccati equation arising in a class of quadratic optimal control problems with infinite dimensional stochastic
differential state equation and infinite horizon cost functional. We allow the coefficients, both in the state equation and
in the cost, to be random.
In such a context backward stochastic Riccati equations are backward stochastic differential equations in the whole positive
real axis that involve quadratic non-linearities and take values in a non-Hilbertian space. We prove existence of a minimal
non-negative solution and, under additional assumptions, its uniqueness. We show that such a solution allows to perform the
synthesis of the optimal control and investigate its attractivity properties. Finally the case where the coefficients are
stationary is addressed and an example concerning a controlled wave equation in random media is proposed. 相似文献
43.
Giovanni Carlo Alfonso Antonio Turturro Maria Pizzoli Mariastella Scandola Giuseppina Ceccorulli 《Journal of Polymer Science.Polymer Physics》1989,27(6):1195-1208
Thermal measurements were carried out to investigate the macrostructure of as-cast poly(vinylidene fluoride) (PVDF)/poly(vinyl pyrrolidone) (PVP) blends. At high PVP content, above about 70 wt.%, the two components form a homogeneously mixed amorphous phase whose Tg varies with composition. Crystals are formed upon casting mixtures richer in PVDF; these systems exhibit complex thermal behavior that cannot be justified by a simple two-phase model. DSC measurements above room temperature on semicrystalline blends show, in addition to the melting of PVDF crystals at temperatures that decrease on increasing PVP content, a glass transition at about 80°C, independent of composition. Experimental results strongly support the hypothesis that an interphase, composed of essentially undiluted noncrystalline PVDF, is always associated with the lamellar crystals. 相似文献
44.
Antonio Roviello Fabio Borbone Antonio Carella Rosita Diana Giuseppina Roviello Barbara Panunzi Antonio Ambrosio Pasqualino Maddalena 《Journal of polymer science. Part A, Polymer chemistry》2009,47(10):2677-2689
The synthesis and the chemical physical characterization of new photoluminescent (PL) chromophores and polymers are reported. Chromophores (oligo‐PPV symmetric derivatives ending with amino groups) are strong blue emitters with a PL quantum yield of ~70% in dioxane solution. They have been used to prepare polyamides by reaction with aliphatic acyl dichlorides in which emitting and non emitting units are alternated. PL properties of the synthesized polyamides have been evaluated in solution and reveal a strong blue emission (PL quantum yield ~60%), To increase the solubility of these systems, oligomers have been purposely prepared and then characterized. They show a peculiar white emission when excited in DMF solution; to get insight into this interesting behavior, asymmetric monoacetylated chromophores have been prepared as model compounds for the chromophoric end groups of the polyamide chains. The emission spectra of these compounds reveal a broad excimeric yellow emission which is responsible, along with the blue emission of the inner chromophoric units, of the overall white emission of the oligomers. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2677–2689, 2009 相似文献
45.
46.
Marcello Bernardara Emanuele Macrì Sukhendu Mehrotra Paolo Stellari 《Advances in Mathematics》2012,229(2):770-803
We prove a categorical version of the Torelli theorem for cubic threefolds. More precisely, we show that the non-trivial part of a semi-orthogonal decomposition of the derived category of a cubic threefold characterizes its isomorphism class. 相似文献
47.
Bayer Arend Lahoz Martí Macrì Emanuele Nuer Howard Perry Alexander Stellari Paolo 《Publications Mathématiques de L'IHéS》2021,133(1):157-325
Publications mathématiques de l'IHÉS - We develop a theory of Bridgeland stability conditions and moduli spaces of semistable objects for a family of varieties. Our approach is based... 相似文献
48.
Mariano Venanzi Giuseppina Pace Lorenzo Stella Manuela Scarselli Fernando Formaggio Giovanni Marletta 《Surface science》2006,600(2):409-416
A novel hexapeptide was functionalized at the N-terminus by a lipoyl group for binding to gold substrates. Owing to the high content of α-aminoisobutyric acid residues, the peptide adopts a rigid helical conformation despite the shortness of its main chain. Binding of the peptide to gold was investigated by quartz crystal microbalance, cyclic voltammetry, X-ray photoelectron spectroscopy, and scanning tunneling microscopy under ultra-high vacuum conditions. Scanning tunneling microscopy experiments revealed that the peculiar self-assembly properties of this short helical peptide determine the complex morphology of the monolayer, showing ‘stripes’, i.e. peptide aggregates horizontally layered on the gold surface, and ‘holes’, i.e. Au vacancy islands coated by the peptide monolayer. 相似文献
49.
Two natural extensions of Jensen’s functional equation on the real line are the equations f(xy) + f(xy
−1) = 2f(x) and f(xy) + f(y
−1
x) = 2f(x), where f is a map from a multiplicative group G into an abelian additive group H. In a series of papers (see Ng in Aequationes Math 39:85–99, 1990; Ng in Aequationes Math 58:311–320, 1999; Ng in Aequationes Math 62:143–159, 2001), Ng solved these functional equations for the case where G is a free group and the linear group
GLn(R), R=\mathbbZ,\mathbbR{{GL_n(R), R=\mathbb{Z},\mathbb{R}}} , is a quadratically closed field or a finite field. He also mentioned, without a detailed proof, in the above papers and
in (see Ng in Aequationes Math 70:131–153, 2005) that when G is the symmetric group S
n
, the group of all solutions of these functional equations coincides with the group of all homomorphisms from (S
n
, ·) to (H, + ). The aim of this paper is to give an elementary and direct proof of this fact. 相似文献
50.
Gallo FR Multari G Federici E Palazzino G Giambenedetti M Petitto V Poli F Nicoletti M 《Natural product research》2011,25(13):1261-1270
Equisetum arvense L. is a herbaceous medicinal plant, commonly known as horsetail, whose extracts have been reported to possess diuretic and haemostatic properties. The aim of this study was to evaluate the use of fingerprint chromatographic methods on commercially available raw materials or preparations of E. arvense L. in order to ascertain their quality and identify possible adulterants using HPLC and HPTLC densitometry. Two chromatographic methods were used to determine the chemical fingerprints of E. arvense and other allied species. The first was based on HPTLC identification followed by densitometric measurement at 350?nm. The second was based on HPLC separation. The ease of sample preparation and the possibility of simultaneous analysis of several samples in a short time make HPTLC a method of choice for the comprehensive quality evaluation of herbal products. 相似文献