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161.
Kontsevich’s formality theorem and the consequent star-product formula rely on the construction of an L
∞-morphism between the DGLA of polyvector fields and the DGLA of polydifferential operators. This construction uses a version
of graphical calculus. In this article we present the details of this graphical calculus with emphasis on its algebraic features.
It is a morphism of differential graded Lie algebras between the Kontsevich DGLA of admissible graphs and the Chevalley–Eilenberg
DGLA of linear homomorphisms between polyvector fields and polydifferential operators. Kontsevich’s proof of the formality
morphism is reexamined in this light and an algebraic framework for discussing the tree-level reduction of Kontsevich’s star-product
is described.
Mathematics Subject Classifications (2000): 53D55, secondary 18G55 相似文献
162.
It is shown that the correctly written “1/k4” propagator in four space-time dimensions leads to a consistent pertubative expansion of a superrenormalizable (asymptotically free) abelian gauge model. Confinement is found in any order of perturbation theory. A discussion of the physical space is sketched and the violation of asymptotic completeness is pointed out. 相似文献
163.
Suppose that U is the resolvent of a Borel right process on a Lusin space X. If is a U-excessive measure on X then we show by analytical methods that for every U-excessive measure with the Radon–Nikodym derivative d/d possesses a finely continuous version. (Fitzsimmons and Fitzsimmons and Getoor gave a probabilistic approach for this result.) We extend essentially a technique initiated by Mokobodzki and deepened by Feyel. The result allows us to establish a Revuz type formula involving the fine versions, and to study the Revuz correspondence between the -finite measures charging no set that is both -polar and -negligible (U being the potential component of ) and the strongly supermedian kernels on X. This is an analytic version of a result of Azéma, Fitzsimmons and Dellacherie, Maisonneuve and Meyer, in terms of additive functionals or homogeneous random measures. Finally we give an application to the context of the semi-Dirichlet forms, covering a recent result of Fitzsimmons. 相似文献
164.
Adrian–Mihail Stoica 《PAMM》2007,7(1):1061101-1061102
The aim of this paper is to present a design methodology for an observer–based fault detection filter. This approach allows to compute a filter gain such that both fault detection and disturbance attenuation requirements are accomplished. The developments are based on H∞ optimization in the discrete–time framework. The existence conditions for the observer–based detection filter are expressed in terms of feasibility of a system of matrix inequalities. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
165.
We consider a proper submarkovian resolvent of kernels on a Lusin measurable space and a given excessive measure ξ. With
every quasi bounded excessive function we associate an excessive kernel and the corresponding Revuz measure. Every finite
measure charging no ξ–polar set is such a Revuz measure, provided the hypothesis (B) of Hunt holds. Under a weak duality hypothesis,
we prove the Revuz formula and characterize the quasi boundedness and the regularity in terms of Revuz measures. We improve
results of Azéma [2] and Getoor and Sharpe [20] for the natural additive functionals of a Borel right process.
Received: 30 April 1997 / Revised version: 17 September 1999 /?Published online: 11 April 2000 相似文献
166.
IDS Collaboration M. V. Lund A. Andreyev M. J. G. Borge J. Cederkäll H. De Witte L. M. Fraile H. O. U. Fynbo P. T. Greenlees L. J. Harkness-Brennan A. M. Howard M. Huyse B. Jonson D. S. Judson O. S. Kirsebom J. Konki J. Kurcewicz I. Lazarus R. Lica S. Lindberg M. Madurga N. Marginean R. Marginean I. Marroquin C. Mihai M. Munch E. Nacher A. Negret T. Nilsson R. D. Page S. Pascu A. Perea V. Pucknell P. Rahkila E. Rapisarda K. Riisager F. Rotaru C. Sotty M. Stanoiu O. Tengblad A. Turturica P. Van Duppen V. Vedia R. Wadsworth N. Warr 《The European Physical Journal A - Hadrons and Nuclei》2016,52(10):304
167.
Mihail N. Popescu William E. Uspal Siegfried Dietrich 《The European physical journal. Special topics》2016,225(11-12):2189-2206
Chemically active colloids locally change the chemical composition of their solvent via catalytic reactions which occur on parts of their surface. They achieve motility by converting the released chemical free energy into mechanical work through various mechanisms, such as phoresis. Here we discuss the theoretical aspects of self-diffusiophoresis, which – despite being one of the simplest motility mechanisms – captures many of the general features characterizing self-phoresis, such as self-generated and maintained hydrodynamic flows “driven” by surface activity induced inhomogeneities in solution. By studying simple examples, which provide physical insight, we highlight the complex phenomenology which can emerge from self-diffusiophoresis. 相似文献
168.
Dr. Uttam Chakraborty Dr. Serhiy Demeshko Prof. Dr. Franc Meyer M. Sc. Christophe Rebreyend Prof. Dr. Bas de Bruin Prof. Dr. Mihail Atanasov Prof. Dr. Frank Neese Dr. Bernd Mühldorf Prof. Dr. Robert Wolf 《Angewandte Chemie (International ed. in English)》2017,56(27):7995-7999
The 15 valence-electron iron(I) complex [CpArFe(IiPr2Me2)] ( 1 , CpAr=C5(C6H4-4-Et)5; IiPr2Me2=1,3-diisopropyl-4,5-dimethylimidazolin-2-ylidene) was synthesized in high yield from the FeII precursor [CpArFe(μ-Br)]2. 57Fe Mössbauer and EPR spectroscopic data, magnetic measurements, and ab initio ligand-field calculations indicate an S= 3/2 ground state with a large negative zero-field splitting. As a consequence, 1 features magnetic anisotropy with an effective spin-reversal barrier of Ueff=64 cm−1. Moreover, 1 catalyzes the dehydrogenation of N,N-dimethylamine–borane, affording tetramethyl-1,3-diaza-2,4-diboretane under mild conditions. 相似文献
169.
Carmen I. Fort Mihai M. Rusu Liviu C. Cotet Adriana Vulpoi Ileana Florea Sandrine Tuseau-Nenez Monica Baia Mihaela Baibarac Lucian Baia 《Molecules (Basel, Switzerland)》2021,26(1)
Multifunctional Bi- and Fe-modified carbon xerogel composites (CXBiFe), with different Fe concentrations, were obtained by a resorcinol–formaldehyde sol–gel method, followed by drying in ambient conditions and pyrolysis treatment. The morphological and structural characterization performed by X-ray diffraction (XRD), Raman spectroscopy, N2 adsorption/desorption porosimetry, scanning electron microscopy (SEM) and scanning/transmission electron microscopy (STEM) analyses, indicates the formation of carbon-based nanocomposites with integrated Bi and Fe oxide nanoparticles. At higher Fe concentrations, Bi-Fe-O interactions lead to the formation of hybrid nanostructures and off-stoichiometric Bi2Fe4O9 mullite-like structures together with an excess of iron oxide nanoparticles. To examine the effect of the Fe content on the electrochemical performance of the CXBiFe composites, the obtained powders were initially dispersed in a chitosan solution and applied on the surface of glassy carbon electrodes. Then, the multifunctional character of the CXBiFe systems is assessed by involving the obtained modified electrodes for the detection of different analytes, such as biomarkers (hydrogen peroxide) and heavy metal ions (i.e., Pb2+). The achieved results indicate a drop in the detection limit for H2O2 as Fe content increases. Even though the current results suggest that the surface modifications of the Bi phase with Fe and O impurities lower Pb2+ detection efficiencies, Pb2+ sensing well below the admitted concentrations for drinkable water is also noticed. 相似文献
170.
Jan Weis Lucian Covaciu Sten Rubertsson Mats Allers Anders Lunderquist Francisco Ortiz-Nieto Håkan Ahlström 《Magnetic resonance imaging》2012
Decrease of the human brain temperature was induced by intranasal cooling. The main purpose of this study was to compare the two magnetic resonance methods for monitoring brain temperature changes during cooling: phase-difference and magnetic resonance spectroscopic imaging (MRSI) with high spatial resolution. Ten healthy volunteers were measured. Selective brain cooling was performed through nasal cavities using saline-cooled balloon catheters. MRSI was based on a radiofrequency spoiled gradient echo sequence. The spectral information was encoded by incrementing the echo time of the subsequent eight image records. Reconstructed voxel size was 1×1×5 mm3. Relative brain temperature was computed from the positions of water spectral lines. Phase maps were obtained from the first image record of the MRSI sequence. Mild hypothermia was achieved in 15–20 min. Mean brain temperature reduction varied in the interval <−3.0; − 0.6>°C and <−2.7; − 0.7>°C as measured by the MRSI and phase-difference methods, respectively. Very good correlation was found in all locations between the temperatures measured by both techniques except in the frontal lobe. Measurements in the transversal slices were more robust to the movement artifacts than those in the sagittal planes. Good agreement was found between the MRSI and phase-difference techniques. 相似文献