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1.
Benzindoles     
A large amount of structural similarity between 4,5-benzindole and naphthalene and between 6,7-benzindole and indole was detected on a basis of a comparison of the absorption, fluorescence, and phosphorescence spectra of isomeric benzindoles with the spectra of indole and naphthalene. A great analogy between indole and 6,7-benzindole as compared with 4,5-benzindole is also observed during the formation of hydrogen bonds, as indicated by the shift in the absorption band of the NH group in the IR spectra of the investigated compounds in the presence of various proton acceptors.  相似文献   
2.
We use QCD sum rules to compute the matrix elements of the ΔB=2 operators appearing in the heavy-quark expansion of the width difference of the B s mass eigenstates. The main focus of our analysis is on the subleading operators R 2 and R 3, which appear at next-to-leading order in the 1/m b expansion. The matrix elements of these operators are already essential for precise phenomenology, but their calculation in lattice QCD is lacking and the values given here provide a first estimate of their values. We conclude that the violation of the factorization approximation for these matrix elements due to non-perturbative vacuum condensates is as low as 1–2%.  相似文献   
3.
An overview of theoretical and experimental studies of the coherent type-B e + e-pair production by photons in aligned crystals performed at Nuclear Physics Institute at Tomsk Polytechnic University is given.  相似文献   
4.
We present an analysis of the static properties of heavy baryons at next-to-leading order in the perturbative expansion of QCD. We obtain analytical next-to-leading order three-loop results for the two-point correlators of baryonic currents with one finite-mass quark field for a variety of quantum numbers of the baryonic currents. We consider both the massless limit and the HQET limit of the correlator as special cases of the general finite-mass formula and find agreement with previous results. We present closed-form expressions for the moments of the spectral density. We determine the residues of physical baryon states using sum-rule techniques.  相似文献   
5.
The processes of establishing of generalized chaotic synchronization in a network of mutually coupled continuous-time systems are investigated. The nature of interaction between the network elements in transitioning from synchronous to asynchronous behavior while increasing the communication parameter is studied. A synchronization regime, the nearest neighbors method, and calculations of the spectrum of Lyapunov exponents are used to clarify features of the interaction between network elements and the occurrence of a generalized chaotic.  相似文献   
6.
We calculate the low-energy limit of heavy quark current correlators within an expansion in the inverse heavy quark mass. The induced low-energy currents built from the gluon fields corresponding to the initial heavy quark currents are obtained from an effective action for gauge fields in the one-loop approximation at the leading order of the expansion. Explicit formulae for the low-energy spectra of electromagnetic and tensor heavy quark current correlators are given. Consequences of the appearance of a nonvanishing spectral density below the two-particle threshold for high precision phenomenology of heavy quarks are discussed quantitatively. Received: 21 April 2001 / Revised version: 18 May 2001 / Published online: 29 June 2001  相似文献   
7.
8.
Volkov  M. K.  Pivovarov  A. A. 《JETP Letters》2019,110(6):394-396
JETP Letters - The well-known [ρ(770), ω(782)] → γ[π, η] electromagnetic decays have been considered within the Nambu-Jona-Lasinio model taking into account...  相似文献   
9.
A method is developed for calculation of the polarization characteristics of radiation based on computer tracking of relativistic particle trajectories. The dependence of the Stokes parameter which defines the polarization properties of the radiation upon photon frequency is determined for characteristic trajectories. Formation of full spectra and the degree of linear polarization for averaging over possible trajectories are considered, and results are compared with available experiments.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 63–68, November, 1986.The authors are indebted to S. A. Vorob'ev for his support in the study and evaluation, to M. I. Podgoretskii and A. P. Potyltsyn for their valuable discussion, and to O. V. Boyarko for assistance in formulating the plan of the study.  相似文献   
10.
Changes in the composition of aqueous NaCl solutions during the course of their treatment with glow-discharge plasma in a gas-liquid plasma-chemical reactor have been studied. A mathematical model involving the steps of oxidation of water molecules and chloride ions and the steps of reduction of their chemical conversion products has been developed. For the first time, it has been found that the hydrogen peroxide content of the solution monotonically decreases with the concentration of NaCl and a change in chlorite, chlorate, and perchlorate concentrations has the appearance of an undulating curve with a maximum at c(NaCl) = 3 g/L. The predominant accumulation of hypochlorite ions in the solution has been detected only in the case of the plasma treatment of the NaCl solutions with concentrations higher than 5 g/L.  相似文献   
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