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61.
G. A. Akopdzhanov V. B. Anikeev V. A. Bezzubov S. P. Denisov A. A. Durum Yu. V. Gilitsky V. M. Korablev V. I. Koreshev A. V. Kozelov E. A. Kozlovsky V. I. Kurbakov V. V. Lipaev A. M. Rybin A. A. Shchukin M. M. Soldatov D. A. Stoyanova K. I. Trushin I. A. Vasilyev 《JETP Letters》2005,82(11):675-678
The g, h, and k Dalitz plot parameters, which are coefficients in a series expansion of the squared module of the matrix element |M(u, v)|2 ∝ 1 + gu + hu 2 + kv 2 (u, v are invariant variables), have been measured for K ± → π±π 0π0 decays using 35 GeV/c hadron beams at the IHEP (Protvino) accelerator. Dependences of parameters and fit quality on the π0π0 mass cut were investigated for the first time. It is shown that the expansion mentioned above does not fit the experimental data near the π+π? mass threshold and that addition of the cubic terms only slightly improves the fit quality. This result indicates the important role of nonanalytical terms in the matrix element that are connected with pion rescattering. A comparison of our data with previous measurements is presented. 相似文献
62.
A. G. Reutova M. R. Ul’maskulov A. K. Sharypov V. G. Shpak S. A. Shunailov M. I. Yalandin V. I. Belousov N. S. Ginzburg G. G. Denisov I. V. Zotova R. M. Rozental’ A. S. Sergeev 《JETP Letters》2005,82(5):263-266
The generation of ultrashort superradiant pulses in the stimulated scattering of an intense microwave (38 GHz) pump wave by a counterpropagating high-current relativistic electron bunch has been observed. Scattered radiation is a single ~200-ps pulse with a peak power of about 1 MW. Owing to the Doppler shift of the radiation frequency, frequencies up to 150 GHz are present in the spectrum of the scattered pulse. 相似文献
63.
The movement of a magnetized particle in the equatorial plane of a magnetic dipole is investigated. Analysis and classification
of trajectory types for such particles are made. It is shown that eight different trajectory types are possible, which depend
on the particle’s energy and on the orientation of its magnetic dipole moment. This permits the use of an axial magnetic field
to move a magnetized particle in any point of the magnetic equatorial plane. 相似文献
64.
A. M. Denisov 《Differential Equations》2009,45(11):1577-1587
We consider two inverse coefficient problems for a quasilinear hyperbolic equation, where the additional information used
for finding the coefficients is the values of the solution on some curve. (This corresponds to measurements performed at a
moving observation point.) The unknown coefficient depends on the space variable in the first inverse problem and on the solution
of the equation in the second inverse problem. We prove theorems of uniqueness of solution to the inverse problems. 相似文献
65.
A. M. Denisov E. V. Zakharov A. V. Kalinin V. V. Kalinin 《Differential Equations》2009,45(7):1034-1043
We consider numerical methods for solving inverse problems that arise in heart electrophysiology. The first inverse problem
is the Cauchy problem for the Laplace equation. Its solution algorithm is based on the Tikhonov regularization method and
the method of boundary integral equations. The second inverse problem is the problem of finding the discontinuity surface
of the coefficient of conductivity of a medium on the basis of the potential and its normal derivative given on the exterior
surface. For its numerical solution, we suggest a method based on the method of boundary integral equations and the assumption
on a special representation of the unknown surface. 相似文献
66.
Absorption spectra of the photoexcited (2-C60)Pd(PPh3)2 complex in benzene were obtained by picosecond and nanosecond laser photolysis. The spectra are compared with those observed for photoexcited states of fullerene C60 and charge-transfer states of C60 complexes with ternary amines. The relaxation kinetics of excited (2-C60)Pd(PPh3)2 complex has three components with characteristic lifetimes 1 = 43 ps, 2 = 1500 ps, and 3 = 1.17 s. The results are discussed in terms of the four-level scheme of the excited complex.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1163–1166, May, 1996. 相似文献
67.
The O-H bond dissociation energies (D O-H) in five alcohols and six acids have been determined from experimental data (rate constants of radical reactions). The ratio of the rate constants of the reactions R1O˙+RH→R1OH+R˙ and R i O˙+RH→R i OH+R˙ and the intersecting parabolas method are used in the estimation procedure. The D O-H values are used to calculate the activation energies and rate constants for hydrogen abstraction from 2-methylbutane, butene-1, and cumene by alkoxyl and carboxyl radicals. The geometric parameters of the transition state are calculated for these reactions. 相似文献
68.
The kinetics of hydrogen exchange in molecular systems with H-bonds has been studied by means of kinetic IR spectroscopy and low-temperature NMR spectroscopy. The experimental values of the rate constants and activation energies for molecules capable of forming H-bonds as both proton donors and proton acceptor are collected and analyzed from the point of view of the influence of H-bond formation ability of the molecules-partners. The evidence available testifies to a molecular mechanism of the H-exchange reactions in inert solvents and in the gas phase via the formation of cyclic bimolecular intermediates. The different mechanisms and the structure of intermediate complex of molecular H-exchange process in inert media are discussed and the possible paths of experimental elucidation of reaction mechanism are offered. 相似文献
69.
T. S. Pokidova E. T. Denisov A. F. Shestakov 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2010,84(3):375-382
The experimental data on the molecular decomposition of olefins ( 1 -pentens) of various structures to two olefins in a gas phase were analyzed by means of the parabola intersection method. The enthalpies and kinetic parameters characterizing such decomposition were calculated for eighteen reactions. Decomposition of olefins representing two-centered concerted re action was found to be characterized by a very high classic potential barrier of thermoneutral reaction (197.4 kJ/mol). The kinetic parameters (activation energy and velocity constant) of fifteen reverse reactions of formation of olefins from two alkenes were calculated using the parabola-intersection method. The factors affect ing the activation energy of the reactions of olefin decomposition and formation are discussed. Quantum chemical calculations of the transition state energy and geometry for six reactions of olefin decomposition were performed. 相似文献
70.
The enthalpies of intramolecular reactions of alkoxy and peroxy radicals formed from polyatomic artemisinin hydroperoxides
and of their bimolecular reactions with C—H, S—H, and O—H bonds of biological substrates were calculated. The activation energies
and rate constants of these reactions were calculated using the intersecting parabolas method. The decomposition of artemisinin
hydroperoxides can initiate the cascade of intramolecular oxidation reactions involving radicals R·, RO·, HO·, HO2·, and RO2·. The main sequences of transformation of these radicals were established. The oxidative destruction of the artemisinin peroxy
derivatives generates radicals RO2·, HO·, and HO2· in an amount of 4.5 radicals per peroxide derivative molecule on the average. The kinetic scheme of oxidative transformations
of the hydroperoxide with four OOH groups and radicals formed from it was constructed using this radical as an example. 相似文献