排序方式: 共有47条查询结果,搜索用时 296 毫秒
31.
D. Montanari S. Leoni D. Mengoni G. Benzoni N. Blasi G. Bocchi P.F. Bortignon A. Bracco F. Camera G. Colò A. Corsi F.C.L. Crespi B. Million R. Nicolini O. Wieland J.J. Valiente-Dobon L. Corradi G. de Angelis F. Della Vedova E. Fioretto A. Gadea D.R. Napoli R. Orlandi F. Recchia E. Sahin R. Silvestri A.M. Stefanini R.P. Singh S. Szilner D. Bazzacco E. Farnea R. Menegazzo A. Gottardo S.M. Lenzi S. Lunardi G. Montagnoli F. Scarlassara C. Ur G. Lo Bianco A. Zucchiatti M. Kmiecik A. Maj W. Meczynski A. Dewald Th. Pissulla G. Pollarolo 《Physics letters. [Part B]》2011
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du Rietz R Ekman J Rudolph D Fahlander C Dewald A Möller O Saha B Axiotis M Bentley MA Chandler C de Angelis G Della Vedova F Gadea A Hammond G Lenzi SM Mărginean N Napoli DR Nespolo M Rusu C Tonev D 《Physical review letters》2004,93(22):222501
Following the heavy-ion fusion-evaporation reaction 32S+24Mg at 95 MeV beam energy the lifetimes of analogue states in the T(z)=+/-1/2 A=51 mirror nuclei 51Fe and 51Mn have been measured using the Cologne plunger device coupled to the GASP gamma-ray spectrometer. The deduced B(E2;27/2(-)-->23/2(-)) values afford a unique opportunity to probe isoscalar and isovector polarization charges and to derive effective proton and neutron charges, epsilon(p) and epsilon(n), in the fp shell. A comparison between the experimental results and several different large-scale shell-model calculations yields epsilon(p) approximately 1.15e and epsilon(n) approximately 0.80e. 相似文献
33.
G.?CattaneoEmail author G.?Della?Vedova A.?Leporati R.?Leporini 《International Journal of Theoretical Physics》2005,44(7):861-873
We extend the notion of conservativeness, given by Fredkin and Toffoli in 1982, to generic gates whose input and output lines
may assume a finite number d of truth values. A physical interpretation of conservativeness in terms of conservation of the energy associated to the data
used during the computation is given. Moreover, we define conservative computations, and we show that they naturally induce a new NP-complete decision problem. Finally, we present a framework that can be used
to explicit the movement of energy occurring during a computation, and we provide a quantum implementation of the primitives
of such framework using creation and annihilation operators on the Hilbert space ℂd, where d is the number of energy levels considered in the framework. 相似文献
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35.
Kh. Gholivand C.O. Della Vedova A. Anaraki Firooz A. Madani Alizadehgan M.C. Michelini R. Pis Diez 《Journal of Molecular Structure》2005,750(1-3):64-71
The reaction of N-benzoylphosphoramidic dichloride with piperidine and 4-methylpiperidine lead to PhC(O)N(H)P(O)R2 with R=piperidine (1) and R=4-methylpiperidine (2) as N-benzoyl-N′,N″-bis(piperidine) phosphoric triamide and N-benzoyl-N′,N″-bis(4-methylpiperidine) phosphoric triamide, respectively. The products have been characterized by 1H, 13C, 31P NMR spectra, and by elemental analysis. The crystalline solid for (1) and (2) consists surprisingly of four and two independent molecules, respectively. There is a disorder in one amine group due to ring inversion in each conformer in compound 1. In the solid state, comparable magnitudes for the stabilization of the stable conformers for the more or less discrete molecules, the polarization effects, hydrogen bonding and the packing effects could be anticipated.
The geometry of compound (1) optimized by density functional calculations at the B3LYP/6-31++G* (d,p) level, is in good agreement with data obtained from X-ray crystallography. 相似文献
36.
Stella L De Rosso M Panighel A Vedova AD Flamini R Traldi P 《Rapid communications in mass spectrometry : RCM》2008,22(23):3867-3872
Resveratrol (3,5,4'-trihydroxystilbene) and piceatannol (3,4,3',5'-tetrahydroxy-trans-stilbene) are phytoalexins present in red grapes and wines. In vitro studies have revealed that piceatannol blocks LMP2A, a viral protein-tyrosine kinase implicated in leukemia, non-Hodgkin's lymphoma and other diseases associated with the Epstein-Barr virus, and has an antimelanoma effect on human melanoma cells. Resveratrol has several beneficial effects on human health, such as anticancer, cardioprotection, antioxidant, inhibition of platelet aggregation and anti-inflammatory activity. In this investigation, the collisional behaviour of deprotonated resveratrol and piceatannol obtained under electrospray conditions is described. The mechanisms involved in the fragmentation pattern of [M-H](-) species of the two compounds were investigated by performing MS(n) experiments, deuterium labelling and accurate mass measurements. 相似文献
37.
Marijke WA de Backer Maike AD Brans Mieneke CM Luijendijk Keith M Garner Dianne MA van den Heuvel R Jeroen Pasterkamp Roger AH Adan 《BMC neuroscience》2010,11(1):94
Background
Multiple neuropeptides, sometimes with opposing functions, can be produced from one precursor gene. To study the roles of the different neuropeptides encoded by one large precursor we developed a method to overexpress minigenes and establish local secretion. 相似文献38.
F. Camera A. Bracco V. Nanal M. P. Carpenter F. Della Vedova S. Leoni B. Million S. Mantovani M. Pignanelli O. Wieland B. B. Back A. M. Heinz R. V. F. Janssens D. Jenkins T. L. Khoo F. G. Kondev T. Lauritsen C. J. Lister B. McClintock S. Mitsuoka E. F. Moore D. Seweryniak R. H. Siemssen R. J. Van Swol D. Hofman M. Thoennessen K. Eisenman P. Heckman J. Seitz R. Varner M. Halbert I. Dioszegi A. Lopez-Martens 《Physics letters. [Part B]》2003,560(3-4):155-160
The spectra of high-energy γ rays emitted by the Giant Dipole Resonance (GDR) built on moderately excited states associated with the evaporation of 0, 1 and 2 nucleons were measured in the 90Zr + 89Y symmetric fusion reaction. The radiative fusion data suggest statistical emission from the compound nucleus. In addition, the analysis of the high-energy γ-ray spectra associated with the different evaporation channels at the present temperature of 0.7 MeV and spin range 15–20 show a fairly narrow width of 5.0±0.35 MeV. This value is smaller than what would be expected in a nucleus where shell effects do not play a role. 相似文献
39.
R. Medda S. Longu E. Agostinelli L. Dalla Vedova J. Z. Pedersen G. Floris A. A. Moosavi-Movahedi A. Padiglia 《Journal of the Iranian Chemical Society》2004,1(2):89-98
In this review the characteristics of the prosthetic group and the role of copper in amine oxidase purified from lentil seedlings are compared with the corresponding features of the amine oxidase isolated from bovine serum. Although both enzymes contain the same organic cofactor, the 6-hydroxydopa (2,4,5-trihydroxyphenethylamine) quinone, the catalytic cycle of lentil seedling amine oxidase operates through a Cu(I)-free-radical intermediate of the cofactor, whereas in bovine serum enzyme the radical form was not observed. The role of the metal in the catalytic mechanism of the two enzymes is also discussed. Moreover, the energetic domains and the effect of the temperature on activity, for both enzymes, are examined using differential scanning calorimetry. 相似文献
40.
A mathematical model is proposed for the process of vacuum superplasticforming. The model exploits the fact that in most industrialapplications the sheet aspect ratio (thickness/sheet width)is small. After an initial consideration of some of the moregeneral properties and the literature of superplastic materials,the elastic/plastic deformation of an internally-inflated thin-walledcylinder is examined. Plates of arbitrary geometry are thenconsidered. A quasisteady model in which the sheet moves througha sequence of steady states is developed. Some simplified closed-formsolutions are examined, but for general cases a system of nonlinearpartial differential equations must be solved numerically. Anefficient and accurate semi-explicit numerical scheme is proposedand a simplified stability analysis is presented; the methodis then used to compute properties of superplastic vacuum mouldedsheets in a number of practically motivated cases. 相似文献