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41.
Raffaella Calabrese Johan A. Elkink Paolo S. Giudici 《The Journal of the Operational Research Society》2017,68(12):1503-1511
The recent European sovereign debt crisis clearly illustrates the importance of measuring the contagion effects of bank failures. Indeed, to better understand and monitor contagion risk, the European Central Bank has assumed the supervision of the largest banks in each of the member states. We propose a measure of contagion risk based on the spatial autocorrelation parameter of a binary spatial autoregressive model. Using different specifications of the interbank connectivity matrix, we estimate the contagion parameter for banks within the Eurozone, between 1996 and 2012. We provide evidence of high levels of systemic risk due to contagion during the European sovereign debt crisis. 相似文献
42.
43.
The functional Ito formula, in the form df() = f( + d ) f(),is formulated and proved in the context of a Lie algebra L associatedwith a quantum (non-commutative) stochastic calculus. Here fis an element of the universal enveloping algebra U of L, andf() + d() f() is given a meaning using the coproductstructure of U even though the individual terms of this expressionhave no meaning. The Ito formula is equivalent to a chaoticexpansion formula for f() which is found explicitly. 1991 MathematicsSubject Classification: primary 81S25; secondary 60H05; tertiary18B25. 相似文献
44.
AnthonyJ. Arduengo III J.C. Calabrese Fredric Davidson H.V. RasikaDias JensR. Goerlich Roland Krafczyk WilliamJ. Marshall Matthias Tamm Reinhard Schmutzler 《Helvetica chimica acta》1999,82(12):2348-2364
Syntheses and characterizations are described for C−H insertion products derived from 1,3-dimesityldihydroimidazol-2-ylidene ( 1 ) with acetylene, acetonitrile, methyl phenyl sulfone, and chloroform. In the reaction with acetylene, both acetylenic H-atoms are reactive so that 1 : 1 and 2 : 1 adducts can be obtained. The acetylene and methyl-phenyl-sulfone adducts are structurally characterized by means of single-crystal X-ray structure determinations. The reactions of 1,3,4,5-tetramethylimidazolidin-2-ylidene ( 8 ) with chloroform or chlorodifluoromethane are shown to yield 2-(dihaloalkyl)imidazolium salts that arise from a failure of the intermediate 2-protioimidazolium salt to capture the initially formed halocarbanion. 相似文献
45.
Vincent T. Calabrese Arshad Khan 《Journal of polymer science. Part A, Polymer chemistry》1999,37(15):2711-2717
Amylose-iodine (AI) complex has been synthesized in aqueous solution without added KI. Complex formation (with solid iodine in amylose solution) is maximized at approximately 35°C and decreases beyond that temperature. Ion-selective electrode (ISE) measurements of an aqueous solution of iodine and AI complex indicate that there is no change in the I− ion concentration when the complex forms. This suggests that I− ions (including I, I, and others) cannot be involved in forming the AI complex. The present work also reports a new and simple method for providing both the iodine-binding capacity (IBC) of amylose and the dissociation mechanism for the AI complex. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2711–2717, 1999 相似文献
46.
Giorgio Della Sala Angelo Fontana Aldo Spinella Gianpiero Calabrese Giuliana d'Ippolito Guido Cimino 《Tetrahedron》2007,63(30):7256-7263
Secondary metabolites of the Mediterranean mollusc Scaphander lignarius from different collection sites have been investigated, proving the constant presence of a number of minor metabolites correlated to the already known lignarenones. Complete characterization of the new metabolites has been supported by enantioselective synthesis. The data are consistent with the origin of this unique class of ω-phenyloctanoids from a common polyketide pathway. 相似文献
47.
T. Clauser D. Diacono G.V. Lamanna V. Stagno V. Variale S. Atutov R. Calabrese V. Guidi U. Tambini E. Mariotti L. Moi P. Lenisa 《Hyperfine Interactions》1998,115(1-4):23-27
A Monte Carlo code combined with a particle tracking program has been used to study a stroboscopic laser diagnostic system
that is able to detect a string-like ordered ion beam. Different ion species have been studied to evaluate the diagnostics
capability.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
48.
G. Stancari S. N. Atutov R. Calabrese L. Corradi A. Dainelli C. de Mauro A. Khanbekyan E. Mariotti P. Minguzzi L. Moi S. Sanguinetti L. Tomassetti S. Veronesi 《The European physical journal. Special topics》2007,150(1):389-392
Francium is one of the best candidates for atomic parity
nonconservation (APNC) and for the search of permanent electric
dipole moments (EDMs). APNC measurements test the weak force
between electrons and nucleons at very low momentum transfers. They
also represent a unique way to detect weak nucleon-nucleon
interactions. EDMs are instead related to the time-reversal
symmetry. Preliminary to these fundamental measurements are
precision studies in atomic spectroscopy and the development of
magneto-optical traps (MOT), which partially compensate for the lack
of stable Fr isotopes. At LNL Legnaro, francium is produced by
fusion of 100-MeV 18O with 197Au in a thick target,
followed by evaporation of neutrons from the compound nucleus.
Francium diffuses inside the hot target (1200 K) and is surface
ionized for injection at 3 keV in an electrostatic beamline.
Typically, we produce 1×106 (210Fr ions)/s for a
primary flux of 1.5×1012 particles/s. We have studied
Fr yields as a function of primary beam energy, intensity, and
target temperature. Information on the efficiency of bulk
diffusion, surface desorption and ionization is deduced. The beam
then enters a Dryfilm-coated cell, where it is neutralized on a
heated yttrium plate. The escape time of neutral Fr (diffusion +
desorption) is approximately 20 s at 950 K, as measured with a
dedicated setup. In the MOT, we use 6 orthogonal Ti:sapphire laser
beams for the main pumping transition and 6 beams from a stabilized
diode repumper. Fluorescence from trapped atoms is observed with a
cooled CCD camera, in order to reach noise levels from stray
light equivalent to approximately 50 atoms. Systematic tests are
being done to improve the trapping efficiency. We plan to further
develop Fr traps at LNL; in parallel, we will study APNC and EDM
techniques and systematics with stable alkalis at Pisa, Siena, and
Ferrara. 相似文献
49.
Bondarenko VE Cymbalyuk GS Patel G Deweerth SP Calabrese RL 《Chaos (Woodbury, N.Y.)》2004,14(4):995-1003
Oscillatory activity in the central nervous system is associated with various functions, like motor control, memory formation, binding, and attention. Quasiperiodic oscillations are rarely discussed in the neurophysiological literature yet they may play a role in the nervous system both during normal function and disease. Here we use a physical system and a model to explore scenarios for how quasiperiodic oscillations might arise in neuronal networks. An oscillatory system of two mutually inhibitory neuronal units is a ubiquitous network module found in nervous systems and is called a half-center oscillator. Previously we created a half-center oscillator of two identical oscillatory silicon (analog Very Large Scale Integration) neurons and developed a mathematical model describing its dynamics. In the mathematical model, we have shown that an in-phase limit cycle becomes unstable through a subcritical torus bifurcation. However, the existence of this torus bifurcation in experimental silicon two-neuron system was not rigorously demonstrated or investigated. Here we demonstrate the torus predicted by the model for the silicon implementation of a half-center oscillator using complex time series analysis, including bifurcation diagrams, mapping techniques, correlation functions, amplitude spectra, and correlation dimensions, and we investigate how the properties of the quasiperiodic oscillations depend on the strengths of coupling between the silicon neurons. The potential advantages and disadvantages of quasiperiodic oscillations (torus) for biological neural systems and artificial neural networks are discussed. 相似文献
50.
LaNb2O6Cl has been prepared by the interaction of LaOCl and Nb2O5. It crystallizes in the orthorhombic space group Pnma with , and the structure was refined to an R value of 1.9%. The most unusual feature of the structure is the participation of one Cl atom in the octahedral environment of Nb(2) combined with one short NbO distance. 相似文献