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排序方式: 共有678条查询结果,搜索用时 140 毫秒
1.
2.
We introduce a general scheme to realize perfect storage of quantum information in systems of interacting qubits. This novel approach is based on global external controls of the Hamiltonian that yield time-periodic inversions in the dynamical evolution allowing a perfect periodic quantum state reconstruction. We illustrate the method in the particularly interesting and simple case of spin systems affected by XY residual interactions with or without static imperfections. The global control is achieved by step time inversions of an overall topological phase of the Aharonov-Bohm type. Such a scheme holds both at finite size and in the thermodynamic limit, thus enabling the massive storage of arbitrarily large numbers of local states, and is stable against several realistic sources of noise and imperfections. 相似文献
3.
Giampaolo Cicogna 《Nonlinear dynamics》2008,51(1-2):309-316
We consider the problem of performing the preliminary “symmetry classification” of a class of quasi-linear PDE’s containing
one or more arbitrary functions: we provide an easy condition involving these functions in order that nontrivial Lie point
symmetries be admitted, and a “geometrical” characterization of the relevant system of equations determining these symmetries.
Two detailed examples will elucidate the idea and the procedure: the first one concerns a nonlinear Laplace-type equation,
the second a generalization of an equation (the Grad–Schlüter–Shafranov equation) which is used in magnetohydrodynamics. 相似文献
4.
Prof. Guido Barone Prof. Aldo La Ginestra 《Journal of Thermal Analysis and Calorimetry》1992,38(12):2563-2563
5.
Proteins obtained from agricultural sources represent a unique feedstock from which to prepare thermally processable polymers. In this study, thermally processed feather keratin films were composted with three-month-old compost inoculum in self-heating laboratory composters for 30 days and temperature and carbon dioxide development monitored. About 24% of the available carbon in the feather keratin polymer (FKP) was metabolized in this time and this may not be high enough for some applications. Degradation of the feather keratin polymers was observed within 10 days with concurrent molecular weight reduction measured using FT-IR. Visual inspection of the polymers also showed destruction of the films. A change in crystallinity was observed in DSC analysis and some degradation processes could be inferred from this as well. 相似文献
6.
The heats of dilution of nine ternary solutions of urea and polyols have been determined at 25°C. Excess enthalpies and their virial coefficients h
xy
have been evaluated and compared with the data reported in the literature for mono- and polyfunctional alcohols and other oxygenated nonelectrolytes. The group additivity approach of Savage and Wood was applied and the contributions to the enthalpy coefficients, due to the water mediated interactions between urea and the functional groups –CH2–, –OH, and –O– were determined. On the other hand, by using empirical combination rules among the cross- and self-enthalpic interaction coefficients it is possible to emphasize the large differences in the behavior (even in the presence of urea) of the polyols (and in particular of cyclitols) and of saccharides. 相似文献
7.
Oesophageal cancer treated by photodynamic therapy alone or followed by radiation therapy 总被引:1,自引:0,他引:1
F Calzavara L Tomio L Corti P L Zorat I Barone A Peracchia L Norberto R F D'Arcais F Berti 《Journal of photochemistry and photobiology. B, Biology》1990,6(1-2):167-174
Photodynamic therapy (PDT) with porphyrins and red light is receiving increasing attention in the management of malignant tumours. At present PDT is primarily indicated for the treatment of superficial or early-stage lesions. At the Department of Radiotherapy and the First Institute of Surgery in Padova (Italy) more than 150 cases of tumours of different types have been treated using this technique. This paper briefly describes 21 cases of superficial oesophageal cancer. A complete response was observed in 11 of 21 cases. Radiation therapy appeared to be very effective as a salvage treatment of non-response patients. 相似文献
8.
Adele Bolognese Gaetano Correale Antonio Lavecchia Vincenzo Barone 《Tetrahedron》2004,60(37):8189-8197
Reaction between quinolinquinone and thiazolidine in basic medium was investigated. 2-Arylthiazolidine-4-carboxylic acid ethyl esters undergo two different cleavages in basic medium, yielding the 1-aryl-2-azadiene and a thiolic species. In the presence of quinolinquinone, the isomeric 1-aryl-3-ethoxycarbonyl-pyridoisoquinolin-5,10-diones and 3-amino-3-ethoxycarbonyl-dihydrothienoquinolin-4,9-diones are formed by a hetero-Diels-Alder reaction and 1,4-Michael addition reaction, respectively. A mechanism for the formation of the reaction products is presented. 相似文献
9.
Guido Barone Bruno Bove Giuseppina Castronuovo Vittorio Elia 《Journal of solution chemistry》1981,10(11):803-809
The excess enthalpies of aqueous solutions of nine polyols were determined at 25°C and reported in the virial form. The most interesting and new feature of this family of solutes is that the sign of the enthalpic pair interaction coefficients hxx is positive for the first members of the series and negative for the higher homologues. Other points are the large differences found among the values of hxx for stereoisomers, whereas pairs of enantiomers show the same values within experimental errors. An application of the group additivity method is also discussed. 相似文献
10.
Antonio Da Settimo Giampaolo Primofiore Bertacchi Maria Cristina Federico Da Settimo Anna Maria Marini 《Journal of heterocyclic chemistry》1995,32(3):941-945
The Ullmann reaction of 8-aminotheophylline or 8-aminocaffeine with 2-chlorobenzoic acid and of 8-bromotheophylline with ethyl-2-aminobenzoate afforded derivatives of three new heterocyclic systems: purino[7,8-α]quinazoline-5,9,11(6H,8H,10H)-trione, purino[8,9-b]quinazoline-2,4,11(1H,3H,5H)-trione and purino[8,7-b]quinazoline-2,4,6(1H,3H,11H)-trione, respectively. 相似文献