On the significance of the vector potential squared

We consider the gauge potential A and argue that the minimum value of the volume integral of A2 (in Euclidean space) may have physical meaning, particularly in connection with the existence of topological structures. A lattice simulation comparing compact and noncompact "photodynamics" shows a jump in this quantity at the phase transition, supporting this idea.     

Determination of the absorption coefficient of solids in the short-wave region of the millimeter band

A technique for measuring the absorption coefficient of solids in the short-wave region of the millimeter band is described. The absorption coefficients of six materials were measured at a wavelength = 2mm.The authors express their gratitude for the interest of Academician A. M. Prokhorov, in whose laboratory this work was done. The authors also wish to thank E. A. Vinogradov for his assistance.     

Theory of the hyperfine structure of the esr line

An operator is derived for the electric quadrupole-quadrupole interaction between the unfilled shell of a paramagnetic ion and the nucleus of this ion. Calculations are carried out for certain iron-group and rare-earth ions. The cases in which this interaction can be reflected in the hyperfine structure of the ESR spectrum are discussed.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 3, pp. 36–42, March, 1971.The authors thank B. M. Kozyrev and A. M. Leushin for discussion of this study, and the authors thank A. A. Antipin for furnishing unpublished experimental data.     

Deuteron decay in the field of the nucleus

The amplitude of the A+d→n+p+A reaction was obtained on the basis of the diagram summation method for the particular configurations of the particle in the final state, when (i) the neutron and proton have a small relative energy, or (ii) one of the nucleons and the nucleus have a small relative energy. It was shown that from the analysis of the experimental data of the reaction A+d→n+p+A and by using the obtained formula the value of the spin-dependent and spin-independent parts of the nucleon-nucleus scattering amplitude can be found.     

The application of the matrix method of successive approximations to the calculation of the force constants of tetramethylmethane

A study is made of the applicability of the matrix method of successive approximations to the calculation of force constants under conditions of insufficient experimentally measured vibrational frequencies using as an example the molecule tetramethylmethane and its deuteron modifications. A solution is guaranteed by fixing some of the force constants in each approximation. A procedure is proposed for the selection of the force constants to be fixed, and the assignment of values to them. The force constants obtained in this way completely satisfactorily reproduce the experimental vibration frequencies.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii Fizika, No. 7, pp. 59–62, July, 1971.     

A Revision of the Models for the Accommodation of Extrinsic Grain Boundary Dislocations

The kinetics of the spreading of electron diffraction contrast from extrinsic grain boundary dislocations (EGBDs) is studied in terms of the dissociation model. For the spreading time an equation similar to those given by Lojkowski-Grabski (W. Lojkowski and M.W. Grabski, in Deformation of Polycrystals: Mechanisms and Microstructures, edited by N. Hansen, A. Horswell, T. Leffers, and H. Lilholt (RisØ Nat. Lab., Roskilde, Denmark, 1981), p. 329.) and Johannesson-Thölen (T. Johannesson and A. Thölen, Metal Sci. J. 6, 189 (1972).) formulae is obtained, but with a much less numeric coefficient which is approximately equal to the coefficient calculated in the incorporation model (A.A. Nazarov, A.E. Romanov, and R.Z. Valiev, Scripta Metall. Mater. 24, 1929 (1990).). A comparison with experimental data shows that the new equation describes the spreading kinetics better than the common formulae.     

Photoacoustic method for the measurement of the nonlinearity parameter of liquids

I.IntroductionThenonlinearityparameterB/Aisanimportantacousticalparameteroffluids.Hitherto,manytheoreticalandexperimentalstudiesforthedeterminahonofthenon1inearityparamctersof1iquidshavebeenrcported.ThemcthodsfordetCrminationofthenonlinearityparamenterofthe1iquidcanbeseparatedintotwocategories:thermodynamicmethod[llandfinite-amp1itudeacousticwavcmethod.The1attercancseparatedfurtherintoharmonicwavemcthodt2]andpulsemethod.Karabutovetal.[31andBozkhovetaI.[4lusedthepulsedlasertogencratetheplane…     

利用中-质微分流探测对称能的高密行为

基于同位旋和动量依赖的强子输运模型IBUU04，研究了¹³²Sn+¹²⁴Sn在三种不同碰撞能量、两种不同对称能作用下，中-质微分流随快度的变化关系. 发现中-质微分流的强度随碰撞能量的增大而增强. 在碰撞能量为400 MeV每核子时，中-质微分流对对称能最为敏感. 关键词： 重离子碰撞 中-质微分流 对称能     

HL-2A装置偏滤器室中性气体压强的初步研究

HL-2A装置上首次实现了偏滤器位形放电。采用专门研制的可在强磁场和强噪声环境下工作的快响应真空电离规对偏滤器室内的中性气体压强进行了测量,给出了HL-2A装置偏滤器有关结构的基础数据。初步研究了偏滤器位形和孔栏位形放电期间偏滤器室中性气体压强的特性。     

The molecular symmetry group of the CO dimer and the assignments of the intermolecular vibrations

Vibrational assignments for some of the lowest energy levels of the CO dimer have been derived purely spectroscopically on the basis of the molecular symmetry, nuclear spin statistics, observed selection rules, and sequence of the transition doublets. Most of the previous assignments of Surin et al. [L.A. Surin, D.N. Fourzikov, T.F. Giesen, S. Schlemmer, G. Winnewisser, V.A. Panfilov, B.S. Dumesh, G.W.M. Vissers, A. van der Avoird, J. Phys. Chem. A 111 (2007) 12238-12247] are confirmed in the present work, and are supported by much clear evidences. One significant revision of that analysis in the present work is identification of the torsional (out-of-plane) excited state, which had been assigned previously to an excited state of the geared (in plane) internal rotation.     

The Connection of the Asymptotics of the Far Field of a Jet with the Velocity Profile at an Orifice

Doklady Physics - A submerged nonswirling jet of a viscous incompressible fluid issuing from an orifice is considered under the boundary layer approximation. A connection of an unknown constant in...     

The question of the metric in the nonlinear theory of a scalar field

The question of the interrelation of the metric and the field in a nonlinear scalar theory of Born-Infeld type is considered. It is shown that the occurrence of a weak perturbation on a strong-field background does not lead to violation of the law of causality if the space-time metric is assumed to depend on the field. The field equation and differential conservation laws obtained on the basis of a Lagrangian formalism are combined into a single system of equations which are invariant under the group of five-dimensional rotations.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 52–55, June, 1978.I wish to thank D. A. Kirzhnits, B. M. Bolotovskii, and A. A. Grib for their interest in this work. The author is also grateful to A. A. Kopylov for stimulating discussions.     

Changes in the zero-point energy of the protons as the source of the binding energy of water to A-phase DNA

The measured changes in the zero-point kinetic energy of the protons are entirely responsible for the binding energy of water molecules to A phase DNA at the concentration of 6 water molecules/base pair. The changes in kinetic energy can be expected to be a significant contribution to the energy balance in intracellular biological processes and the properties of nano-confined water. The shape of the momentum distribution in the dehydrated A phase is consistent with coherent delocalization of some of the protons in a double well potential, with a separation of the wells of 0.2??.     

Status and plans of the ion program of NA61 at the CERN SPS

The NA61/SHINE at the CERN SPS is a new experiment to study hadron production in p+p, p+A, h+A and A+A interactions. The main goal of the NA61 ion program is to explore the phase diagram (T ? ?? _B ) of strongly interacting matter. In particular, we plan to study the properties of the onset of deconfinement and to search for the signatures of the critical point. A two-dimensional scan of the phase diagram will be performed by varying the energy (13A?C158A GeV) and system size (p+p, Be+Be, Ar+Ca, Xe+La) of collisions. This paper summarizes the status and plans of the NA61/SHINE ion program. In particular the detector upgrades, data taking schedule and the first results on spectra and correlations are discussed.     

On the unitarization of the Born approximation

A new approximation for the elastic scattering transition matrix is suggested. This approximation satisfies the unitarity condition. A modified Born series is introduced which has this unitarized Born approximation as the leading term. The series is applied to the solvable case of scattering by a separable potential and is found to converge in a wider region of energies than that of the conventional Born series.     

Effect of shape anisotropy on the phase diagram of the Gay-Berne fluid

We have used the density functional theory to study the effect of molecular elongation on the isotropic-nematic, isotropic-smectic A and nematic-smectic A phase transitions of a fluid of molecules interacting via the Gay-Berne intermolecular potential. We have considered a range of length-to-width parameter 3.0 ⩽ x₀ ⩽ 4.0 in steps of 0.2 at different densities and temperatures. Pair correlation functions needed as input information in density functional theory are calculated using the Percus-Yevick integral equation theory. Within the small range of elongation, the phase diagram shows significant changes. The fluid at low temperature is found to freeze directly from isotropic to smectic A phase for all the values of x₀ considered by us on increasing the density while the nematic phase stabilizes in between isotropic and smectic A phases only at high temperatures and densities. Both isotropic-nematic and nematic-smectic A transition density and pressure are found to decrease as we increase x₀. The phase diagram obtained is compared with computer simulation result of the same model potential and is found to be in good qualitative agreement.     

Republication of: On the physical significance of the Riemann tensor

This Golden Oldie is a reprinting of a paper by F. A. E. Pirani first published in 1956. It is accompanied by a reprinting of a paper by J. L. Synge first published in 1934. Together these papers pointed the way to the interpretation of geodesic deviation and its relation to the curvature tensor. These two Golden Oldies are accompanied by an Golden Oldie Editorial containing an editorial note written by A. Trautman, and by the biography of F. Pirani written by himself and commented by A. Trautman. An editorial note to this paper and a biography can be found in this issue preceding this Golden Oldie and online via doi:. Original paper: F. A. E. Pirani, Acta Physica Polonica 15, 389–405 (1956). Reprinted with the kind permission of the Editors of Acta Physica Polonica, and of Felix Pirani.     

Mean free path effects on the current perpendicular to the plane magnetoresistance of magnetic multilayers

We have carried out an experimental and theoretical study of the magnetoresistance MR(H) in the CPP (current perpendicular to the planes) mode for two types of magnetic multilayers that differ only in the ordering of the magnetic layers: [Co(10 A)/Cu(200 A)/Co(60 A)/Cu(200 A)](N) and [Co(10 A)/Cu(200 A)](N)[Co(60 A)/Cu(200 A)](N). The series resistor model predicts that in the CPP mode MR(H) is independent of the ordering of the layers. Nevertheless, the measured MR(H) curves were found to be completely different for the two cases. Calculations based on a realistic band structure and the Kubo formula show that the results are a consequence of a long mean free path.     

椭圆量子群极小表示的系数代数

给出了对应于A(1)n–1面模型的玻尔兹曼权的L矩阵及FelderAn系列椭圆量子群的极小表示(所有矩阵元均为c数)的系数代数.这个代数满足杨–Baxter方程.同时,对此代数还给出了一组PBW基.