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排序方式: 共有119条查询结果,搜索用时 31 毫秒
61.
LUNA Collaboration F. Ferraro M. P. Takács D. Piatti V. Mossa M. Aliotta D. Bemmerer A. Best A. Boeltzig C. Broggini C. G. Bruno A. Caciolli F. Cavanna T. Chillery G. F. Ciani P. Corvisiero L. Csedreki T. Davinson R. Depalo G. D’Erasmo A. Di Leva Z. Elekes E. M. Fiore A. Formicola Zs. Fülöp G. Gervino A. Guglielmetti C. Gustavino Gy. Gyürky G. Imbriani M. Junker I. Kochanek M. Lugaro L. E. Marcucci P. Marigo R. Menegazzo F. R. Pantaleo V. Paticchio R. Perrino P. Prati L. Schiavulli K. Stöckel O. Straniero T. Szücs D. Trezzi S. Zavatarelli 《The European Physical Journal A - Hadrons and Nuclei》2018,54(3):44
62.
Luisa Sciortino Fabrizio Messina Gianpiero Buscarino Simonpietro Agnello Marco Cannas Franco M. Gelardi 《Journal of nanoparticle research》2017,19(6):228
We describe the simple fabrication of SiO2 sol-gel monoliths embedding highly luminescent carbon nanodots (CDs) sensitive to metal ions. The pristine CDs we synthesize display an intense dual emission consisting in two fluorescence bands in the green and violet region, and we demonstrate that this photoluminescence is substantially unchanged when the dots are incorporated in the SiO2 matrix. The emission of these CDs is quenched by interactions with Cu2+ ions, which can be used to detect these ions with a detection limit of 1 μM. The chromophores remain accessible to diffusing Cu2+ ions even after embedding CDs in the sol-gel monolith, where their detection capabilities are preserved. Such a result provides the proof-of-principle of a new sensing scheme, where CDs are exploited as active sensing centers of metal transition ions within a solid-state device. The different interaction mechanisms of CDs with copper, in liquid and solid phase, are analyzed in detail and discussed in terms of different accessibility of their chromophores when the dots are incorporated in the SiO2 matrix. 相似文献
63.
Bemmerer D Confortola F Costantini H Formicola A Gyürky G Bonetti R Broggini C Corvisiero P Elekes Z Fülöp Z Gervino G Guglielmetti A Gustavino C Imbriani G Junker M Laubenstein M Lemut A Limata B Lozza V Marta M Menegazzo R Prati P Roca V Rolfs C Alvarez CR Somorjai E Straniero O Strieder F Terrasi F Trautvetter HP;LUNA Collaboration 《Physical review letters》2006,97(12):122502
The nuclear physics input from the 3He(alpha,gamma)7Be cross section is a major uncertainty in the fluxes of 7Be and 8B neutrinos from the Sun predicted by solar models and in the 7Li abundance obtained in big-bang nucleosynthesis calculations. The present work reports on a new precision experiment using the activation technique at energies directly relevant to big-bang nucleosynthesis. Previously such low energies had been reached experimentally only by the prompt-gamma technique and with inferior precision. Using a windowless gas target, high beam intensity, and low background gamma-counting facilities, the 3He(alpha,gamma)7Be cross section has been determined at 127, 148, and 169 keV center-of-mass energy with a total uncertainty of 4%. The sources of systematic uncertainty are discussed in detail. The present data can be used in big-bang nucleosynthesis calculations and to constrain the extrapolation of the 3He(alpha,gamma)7Be astrophysical S factor to solar energies. 相似文献
64.
Ferrous glycine sulfate pentahydrate [Fe(glycine)(SO4)·5H2O with glycine = C2H5NO2], contained in the supplement for treating iron deficiency anaemia, commercially known as ferro sanol duodenal®, was characterized by laboratory X‐ray powder diffraction (XRPD), scanning electron microscope (SEM), and infrared spectroscopy (IR). The thermal behavior was investigated by thermal analysis (TGA and DTA) and temperature‐dependent in situ XRPD measurements. Furthermore, the phase transitions to a less hydrated form [Fe(glycine)(SO4)·3H2O] and successively to the anhydrous form were demonstrated to occur in the crystalline solid state. Compared to the crystal structure of the pentahydrate, the trihydrate exhibits a different coordination environment of the iron sites where glycine ligands bridge iron forming a 1D polymeric chain structure. From detailed structural comparison, the mechanism of the phase transitions can be concluded. 相似文献
65.
Gianpiero Cattaneo Carlo Dalla Pozza Claudio Garola Giuseppe Nisticò 《International Journal of Theoretical Physics》1988,27(11):1313-1349
We make a critical analysis of the basic concepts of the Jauch-Piron (JP) approach to quantum physics. Then, we exhibit a formalized presentation of the mathematical structure of the JP theory by introducing it as a completely formalized syntactic system, i.e., we construct a formalized languageL
e
and formally state the logical-deductive structure of the JP theory by means ofL
e
. Finally, we show that the JP syntactic system can be endowed with an intended interpretation, which yields a physical model of the system. A mathematical model endowed with a physical interpretation is given which establishes (in the usual sense of the model theory) the coherence of the JP syntactic system. 相似文献
66.
A. Lleres O. Bartalini V. Bellini J. P. Bocquet P. Calvat M. Capogni L. Casano M. Castoldi A. D'Angelo J. -P. Didelez R. Di Salvo A. Fantini C. Gaulard G. Gervino F. Ghio B. Girolami A. Giusa M. Guidal E. Hourany V. Kouznetsov R. Kunne A. Lapik P. Levi Sandri D. Moricciani A. N. Mushkarenkov V. Nedorezov L. Nicoletti C. Perrin C. Randieri D. Rebreyend F. Renard N. Rudnev T. Russew G. Russo C. Schaerf M. -L. Sperduto M. -C. Sutera A. Turinge 《The European Physical Journal A - Hadrons and Nuclei》2007,31(1):79-93
Beam asymmetries and hyperon recoil polarizations for the reactions γp → K
+Λ and γp → K
+Σ0 have been measured from the threshold production to 1500MeV with the GRAAL facility located at the ESRF in Grenoble. These
results complement the database for the beam asymmetry, covering for the first time the production threshold region. Recent
theoretical analyses are presented for which the beam asymmetry data bring interesting new information and allow to better
determine some resonance parameters. Most importantly, these results strengthen the need of a new D13 state around 1900MeV. 相似文献
67.
Anna E. Caprifico Elena Polycarpou Peter J. S. Foot Gianpiero Calabrese 《Macromolecular bioscience》2021,21(1)
Chitosan‐based nanocarriers (ChNCs) are considered suitable drug carriers due to their ability to encapsulate a variety of drugs and cross biological barriers to deliver the cargo to their target site. Fluorescein isothiocyanate‐labeled chitosan‐based NCs (FITC@ChNCs) are used extensively in biomedical and pharmacological applications. The main advantage of using FITC@ChNCs consists of the ability to track their fate both intra and extracellularly. This journey is strictly dependent on the physico‐chemical properties of the carrier and the cell types under investigation. Other applications make use of fluorescent ChNCs in cell labeling for the detection of disorders in vivo and controlling of living cells in situ. This review describes the use of FITC@ChNCs in the various applications with a focus on understanding their usefulness in labeled drug‐delivery systems. 相似文献
68.
Rational design, synthesis, and evaluation of key analogues of CC-1065 and the duocarmycins 总被引:2,自引:0,他引:2
Tichenor MS MacMillan KS Stover JS Wolkenberg SE Pavani MG Zanella L Zaid AN Spalluto G Rayl TJ Hwang I Baraldi PG Boger DL 《Journal of the American Chemical Society》2007,129(45):14092-14099
The design, synthesis, and evaluation of a predictably more potent analogue of CC-1065 entailing the substitution replacement of a single skeleton atom in the alkylation subunit are disclosed and were conducted on the basis of design principles that emerged from a fundamental parabolic relationship between chemical reactivity and cytotoxic potency. Consistent with projections, the 7-methyl-1,2,8,8a-tetrahydrocyclopropa[c]thieno[3,2-e]indol-4-one (MeCTI) alkylation subunit and its isomer 6-methyl-1,2,8,8a-tetrahydrocyclopropa[c]thieno[2,3-e]indol-4-one (iso-MeCTI) were found to be 5-6 times more stable than the MeCPI alkylation subunit found in CC-1065 and slightly more stable than even the DSA alkylation subunit found in duocarmycin SA, placing it at the point of optimally balanced stability and reactivity for this class of antitumor agents. Their incorporation into the key analogues of the natural products provided derivatives that surpassed the potency of MeCPI derivatives (3-10-fold), matching or slightly exceeding the potency of the corresponding DSA derivatives, consistent with projections made on the basis of the parabolic relationship. Notable of these, MeCTI-TMI proved to be as potent as or slightly more potent than the natural product duocarmycin SA (DSA-TMI, IC50 = 5 vs 8 pM), and MeCTI-PDE2 proved to be 3-fold more potent than the natural product CC-1065 (MeCPI-PDE2, IC50 = 7 vs 20 pM). Both exhibited efficiencies of DNA alkylation that correlate with this enhanced potency without impacting the intrinsic selectivity characteristic of this class of antitumor agents. 相似文献
69.
Mastinu Gianpiero Biggio Danilo Della Rossa Fabio Fainello Marco 《Nonlinear dynamics》2020,99(4):2801-2818
Nonlinear Dynamics - The stability of the straight ahead running motion of automobiles is studied with proper theoretical tools pertaining to bifurcation theory. The study is both theoretical and... 相似文献
70.
This paper studies the state-effect-probability structure associated with thequantum mechanics of nonlinear (homogeneous, in general nonadditive) operatorson a Hilbert space. Its aim is twofold: to provide a concrete representation ofthe features of nonlinear quantum mechanics on a Hilbert space, and to showthat the properties of the nonlinear version of quantum mechanics here describedhave the structure of a classical logic. 相似文献