Resistive plate chambers for muon detection at LHC

One resistive plate chamber made of Chinese materials and one Italian resistive plate chamber have been tested in the Gamma Irradiation Facility (GIF) at CERN on a high intensity muon beam together with a¹³⁷Cs source to give a uniform photon background, and simulating conditions close to those expected for an LHC muon detector. The results are analyzed. Good space and time resolutions are obtained which satisfy the future CMS experiment requirements. The detection efficiency is different between two RPCs against a high irradiation background. The reason is discussed.     

甲基氰乙基纤维素／二氯乙酸液晶溶液的红外研究

本文用FTIR研究了甲基氰乙基纤维素/二氯乙酸溶液相转变过程中分子间相互作用的变化。发现溶液中分子之间的相互作用随溶液结构的改变而变化。随着浓度的增大,溶液由各向同性态向各向异性态转变,分子产生有序排列,导致某些氢键被增强或削弱,使基团的红外吸收谱带发生位移。当加热液晶溶液时,各向异性态向各向同性态转变,也使基团的红外吸收谱带位移。     

New mixed plate-bending elements with shear strain interpolations

This paper is concerned with two mixed plate-bending elements with shear strain interpolations, a quadrilateral element and an 8-node serendipity-type element based on discussions on the element proposed in Ref.[1]. The shear strains and inner-forces in the natural coordinates are interpolated in an element and then transformed into Cartesian coordinates in accordance with covariant and contravariant tensor transformations, respectively. The quadrilateral element coincides with the element in Ref.[1] when it is rectangular. Numerical examples show that the two new elements are free from shear locking and spurious kinematic modes under regular and irregular meshes and have the advantages of being insensitive to element distortion and able to give fairly accurate results.The Project supported by National Natural Science Foundation of China.     

复合消色差补偿器

给出一种新的三元复合式消色差补偿器，该补偿器具有调节方便、精度高、在一定波长范围内消色差性能良好等优点。     

THE METHOD OF THE RECIPROCAL THEOREM OF FORCED VIBRATION FOR THE ELASTIC THIN RECTANGULAR PLATES(Ⅱ)—RECTANGULAR PLATES WITH TWO ADJACENT CLAMPED EDGES

In this paper,applying the method of reciprocal theorem,we give the distributions ofthe amplitude of bending moments along clamped edges and the amplitude of deflectionsalong free edges of rectangular plates with two adjacent clamped edges under harmonicdistributed and concentrated loads.     

Scanning electrochemical microscopy (SECM) of nanolitre droplets using an integrated working/reference electrode assembly

Scanning electrochemical microscopy (SECM) has been performed in the restricted space of nanolitre droplets with a robust and easy-to-handle coaxial electrode assembly centring a Pt microdisk in a circular Ag electrode. Straightforward and reproducible fabrication of the specially designed probe tips was achieved by using Tollens reaction to chemically deposit a uniform and well-adhering layer of silver on the body of a glass-insulated Pt microdisk electrode. The suitability of the novel dual-electrode SECM tip for measurement in small volumes was evaluated by imaging an array of four Pt band microelectrodes in 500 nL electrolyte.     

Determination of the parameters of a three-dimensional heat release region in a supersonic stream from pressure measurements

Three-dimensional steady-state supersonic flow with weak heat release is analyzed. Two conjugate problems are considered: determination of the forces exerted on surfaces surrounding a given heat source and determination of the release region and the amount of heat released from pressure measurements in the surrounding space. Features of the three-dimensional flow are found. The characteristic properties of the three-dimensional flow are illustrated with reference to a spherical Gaussian source.     

Viscous Fingering Instability in Porous Media: Effect of Anisotropic Velocity-Dependent Dispersion Tensor

The viscous fingering of miscible flow displacements in a homogeneous porous media is examined to determine the effects of an anisotropic dispersion tensor on the development of the instability. In particular, the role of velocity-dependent transverse and longitudinal dispersions is investigated through linear stability analysis and nonlinear simulations. It is found that an isotropic velocity-dependent dispersion tensor does not affect substantially the development of the instability and effectively has the same effect as molecular diffusion. On the other hand, an anisotropic velocity-dependent dispersion tensor results in different instability characteristics and more intricate finger structures. It is shown that anisotropic dispersion has profound effects on the development of the fingers and on the mechanisms of interactions between neighboring fingers. The development of the new finger structures is explained by examining the velocity field and characterized qualitatively through a spectral analysis of the average concentration and an analysis of the variations of the sweep efficiency and relative contact area.     

Comments on Reply to Comments on “Non-Darcian Forced Convection Flow of Viscous Dissipating Fluid Over a Flat Plate Embedded in a Porous Medium”

This note is a comment on the reply by Aydin and Kaya (Transp Porous Media (to appear), 2008b) to comments by Rees and Magyari (Transp Porous Media (to appear), 2008) on an article by Aydin and Kaya (Transp Porous Media (to appear), 2008a) concerning the combined effects of viscous dissipation and surface mass flux on the forced convection boundary-layer flow in a saturated porous medium modeled by the Brinkman equation. It is argued that the statements by Rees and Magyari are in fact appropriate. The thermal boundary condition imposed at the edge of the boundary-layer by Aydin and Kaya is incompatible with the energy equation, and thus the results of their paper are inconsistent with the physics of the situation. The attempts of Aydin and Kaya to justify their paper are flawed by an inappropriate assumption and calculations with an insufficiently large parameter.