Analytic Properties of the Transition Admittance of an Infinite Plate in a medium and the Regularization of Boundary-Contact Integrals in Acoustics

A condition for regularization of boundary-contact integrals in two-dimensional problems of acoustics is considered. With an example of the simplest boundary-contact problem of acoustics, it is shown that a known sufficient condition for regularization is also a necessary one. The study of analytic properties of the transition admittance of an infinite plate that is in contact with a medium is conducted in order to obtain this statement. The considerations are carried out in general terms. The results obtained may be used in arbitrary models of plate theory, and they also may be adapted to boundary-contact problems of another physical nature. Bibliography: 9 titles.     

Working group report: Collider Physics

This is summary of the activities of the working group on collider physics in the IXth Workshop on High Energy Physics Phenomenology (WHEPP-9) held at the Institute of Physics, Bhubaneswar, India in January 2006. Some of the work subsequently done on these problems by the subgroups formed during the workshop is included in this report.     

The Transformation Matrix of Vibrational Waves

The general theory on the transformation of elastic waves at a rigid nodal junction of an arbitrary number of thin plates is considered. The notion of transformation marix is introduced, and a way for computing it and numerical examples are given. Properties of the transformation matrix resulted from the reciprocity principle and the energy conservatin law are studied. In particular, a new relation that expresses the energy conservation low for the case where a wave damped in the direction of the joint of plates is a source of a field is obtained. Bibliography: 18 titles.     

Information on the work of the St. Petersburg Seminar on Computational and Theoretical Acoustics with the Scientific Council of the Russian Academy of Sciences on Acoustics in 2008

Acoustical Physics -     

Collision-induced absorption of hydrogen deuteride dissolved in liquid neon

First observation of the collision-induced IR-fundamental band of hydrogen deuteride (HD) in liquid neon is described. A developed intracell rattling model yields highly accurate fits to the measured diffuse Q1-branch profiles enabling a detailed shape analysis of the adjacent spectral lines. Strong intracollisional anticorrelation found at the location of the permanent dipole-allowed R1(0) transition is interpreted in the frame of the Fano-Mori theory. A new striking narrowing effect (by 30%) is observed on the sharp Q(q)(1)(0) vibrational line with increasing HD concentration in solutions. The T1(0), U1(0) and a few pair transitions are identified in the spectrum.     

On the singularity of Green's tensor for a perfectly conducting semi-infinite cone

This paper is intended to clarify a misunderstanding concerningthe source singularity of the electric Green's tensor for aperfectly conducting semi-infinite cone of circular cross-section.Tai's series expansion of the Green's tensor is known to lacka singular term at the source region. Jones has reconstructedthe solution to this problem and has pointed out the differencebetween his result and that of Tai. The aim of our paper isto demonstrate that, although Jones's closed-form solution iscorrect, there is a mistake in his comparison with Tai's seriessolution. We conclude that one of the two additional singularterms that Jones claims as missing from Tai's formula must beomitted. Besides, we compare Jones's closed-form solution withSmyshlyaev's solution to the very same problem. We concludethat the magnetic field expressions given by Jones and Smyshlyaevcoincide, but a singular term is missing from Smyshlyaev's expressionfor the electric field.     

Reconstruction of the Q band spectrum of the 1285-cm−1 transition in the CO2 molecule from measurements of a pulsed response

By using the method of nonstationary spectroscopy of coherent anti-Stokes Raman scattering, pulsed responses of the Q band of the vibrational-rotational transition in the CO₂ molecule at a frequency of 1285 cm^?1 are measured under conditions of broadening close to the Doppler type. The ratios of the amplitudes of Q-band components at known frequencies are obtained by fitting to the measured pulsed responses.