A Legendre expansion and some exact solutions basic to the McCormack model for binary gas mixtures

A Legendre expansion of the scattering kernel, a conservation condition and some exact solutions are reported for the McCormack kinetic model that is used to describe a binary mixture of rarefied gases.     

Stability in Shells

This paper charts the various ways in which a close working relationship with Michael Thompson, during our early years within the Stability Research Group at UCL, came to have such a profound influence on the direction of my own research activities. In particular, his fascination with energy and its use in providing a systematic framework for looking at the initial post-buckling of systems was especially contagious, opening up for me new ways of approaching the interpretation of shell buckling. In a sense my own work moved from chaos to stability in shells while Mike's was the reverse.     

Stress–strain field around elliptic cavities in elastic continuum

The paper is related to the determination of stress and strain fields around unsupported, stress free surface of an ellipsoidal cavity situated in a stressed elastic continuum. This is a most common requirement for the estimate of structural safety of underground rock excavations. The analytical approach elaborated in the paper avoids the solutions of the same problem that lead to expressions that contain rather complex integrations. The significant simplifications of all expressions from definition of the problem to its resolving have been achieved by application of ellipsoidal coordinates. Thus the presented solutions provide the applicable and explicit expressions for stresses and strains developed in infinite series with easily determinable coefficients by the use of contemporary mathematical packages. The numerical examples are also included to confirm the convergence of the obtained solutions.     

Bifurcations in nonlinear models of fluid-conveying pipes supported at both ends

Stationary bifurcations in several nonlinear models of fluid conveying pipes fixed at both ends are analyzed with the use of Lyapunov–Schmidt reduction and singularity theory. Influence of the gravitational force, curvature and vertical elastic support on various properties of bifurcating solutions are investigated. In particular the conditions for occurrence of supercritical and subcritical bifurcations are presented for the models of Holmes, Thurman and Mote, and Paidoussis.     

Study of the effect of γ-absorbed dose on degradation of polypropylene/starch-filled polymer containing photo-initiators by spectroscopic methods

γ irradiated samples containing photo-initiators (PIs) with and without corn starch at 0–60 kGy were studied by UV spectrophotometer and FTIR. A linear decrease in the wavelength of absorbance maximum of each aromatic PI is observed by increase in the dose. The presence of starch in the sample caused a fluctuation of the absorptions. An increase in carbonyl formation due to the effect of a PI was detected. Ferric stearate and Irgacure 184 showed the highest and lowest effect respectively.     

PREFACE

This special issue contains 16 papers selected from the presentations at the 8th International Conference on Fundamentals of Fracture (ICFF Ⅷ),which was successfully held during 3-7 January 2008 at the Clear Water Bay and Nansha Campuses,Hong Kong University of Science & Technology.ICFF are the series of international conferences on fundamentals of fracture with the highest academic reputation.ICFF Ⅷ is the successor of the previous seven held at NBS,Gaithersburg (USA,1983),Gatlinburg (USA,1985),Irsee (Germany,1989),Urabandai (Japan,1993),NIST,Gaithersburg (USA,1997),Cirencester (UK,2001),and Nancy (France,2005).     

Asymptotic solutions of coupled dynamic problems of thermoelasticity for isotropic plates

The asymptotic method of solving boundary-value problems of the theory of elasticity for anisotropic strips and plates is used to solve coupled dynamic problems of thermoelasticity for plates, on the faces of which the values of the temperature function and the values of the components of the displacement vector or the conditions of the mixed problem of the theory of elasticity are specified. Recurrence formulae are derived for determining the components of the displacement vector, the stress tensor and for the temperature field variation function of the plate.     

Cluster dynamics of a uniform chain of dissipatively coupled rotators

The existence and stability of stationary cluster structures in uniform chains of dissipatively coupled rotators is investigated. Cluster synchronization is interpreted as the classical synchronization of cluster rotators, which are elementary structure-forming objects. The complete set of types of cluster rotators and simple cells is defined. This definition is equivalent to the definition of the complete set of types of cluster structures. The completeness of this set is proved. The problem of the stability of cluster structures is solved. Physical examples of chains of rotators and a physical interpretation of the results of this research are given.     

Theoretical and experimental studies on the aerodynamic instability of a two-dimensional circular cylinder with a moving attachment

Rain–wind induced vibration of cables in cable-stayed bridges is a worldwide problem of great concern. The effect of the motion of water rivulets on the instability of stay cables has been recognized as one of the mechanisms of this complex phenomenon. In order to investigate how the motion of rivulets affects the unstable vibration of cables without considering the effects of axial flow and axial vortex, a real three-dimensional cable was modeled as a two-dimensional circular cylinder, around which an attachment representing the rivulet can move. This could also be regarded as a new kind of two-dimensional 2-dof dynamic system. This paper studies the aerodynamic instability of the system theoretically and experimentally. Equations governing the motions of the cylinder and the attachment are first established. The Lyapunov stability criterion is applied to the equations of motion to derive the criterion for the unstable balance angle of the attachment. Moreover, a new two-dimensional 2-dof cable model system with a movable attachment is designed and tested in a wind tunnel. Parametric studies are carried out to investigate the effects of major factors such as wind speed, frequency and damping of the dynamic system on the unstable balance angle of the rivulet attachment. Theoretical and experimental results match well. These results may be valuable in elucidating the mechanism of rain–wind induced vibration of stay cables.     

矿物材料在电磁屏蔽中的应用研究

为解决电磁辐射污染问题,介绍了国内外矿物材料应用在电磁屏蔽方面的研究及最新进展,尤其是在建筑混凝土、涂料以及纳米矿物材料中的应用,归纳总结了其屏蔽特点和屏蔽效果,并对发展前景作出了展望.