Conditions database system of the COMPASS experiment

The CERN SPS experiment COMPASS has integrated a Conditions Database System in its off-line software. The system is used to manage time-dependent information, detector condition, calibration, and geometrical alignment information, by using a package provided by the CERN IT/DB. This integrated system consists of administration tools, a data handling library, and data transfer software from the detector control system to the Conditions Database. In this paper, the status of the Conditions Database project is described, and the results of the performance test on the COMPASS computing farm are given.     

PSEUDO: applications of streams and lazy evaluation to integrable models

Procedures to manipulate pseudo-differential operators in MAPLE are implemented in the program PSEUDO to perform calculations with integrable models. We use lazy evaluation and streams to represent and operate with pseudo-differential operators. No order of truncation is needed since terms are produced on demand. We give a series of concrete examples.

Program summary

Title of program: PSEUDOCatalogue identifier: ADUOProgram summary URL:http://cpc.cs.qub.ac.uk/summaries/ADUOProgram obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: NoneComputers: IBM PCOperating systems under which the program has been tested: Windows systemsProgramming language used: MAPLE V Release 8Memory required to execute with typical data: Depends strongly on the problemNo. of lines in distributed program, including test data, etc.: 737No. of bytes in distributed program, including test data, etc.: 8822Distribution format: tar.gzNature of mathematical problem: Determination of equations of motion and conserved charges in the theory of integrable modelsMethods of solution: Pseudo-differential Lax operatorsRestrictions on the complexity of the problem: Handles only one-dimensional pseudo-differential operators with scalar coefficientsTypical running time: This depends strongly on the problem to be solved, usually taking from a few seconds to a few minutesUnusual features of the program: Use of delayed evaluation and streams     

纵论国外黑白照相胶片市场的发展

本文扼要地综述了黑白照相胶片市场的概况，现状和展望，重点阐述了各主要跨国公司，目前在市场上销售的普通黑白照相胶片系列，染料黑白下系列，黑白一次性相机等产产品，并指出这是一个正在不断增长的市场，还将蓬勃发展。     

Characteristics of high-k gate oxide prepared by oxidation of multi-layered Hf/Zr/Hf/Zr/Hf metal films

We investigated the physical and electrical properties of Hf-Zr mixed high-k oxide films obtained by the oxidation and annealing of multi-layered metal films (i.e., Hf/Zr/Hf/Zr/Hf, ∼ 5 nm). We demonstrated that the oxidation of multi-layered metal films results in two distinctive amorphous layers: That is, Hf-Zr mixed oxide film was formed on the top of silicate film due to inter-diffusion between Hf and Zr layer. This film shows the improved dielectric constant (k) and the raised crystallization temperature. Compared with HfO₂ and ZrO₂ gate dielectric, the crystallization temperature of Hf-Zr mixed oxides was raised by more than 200 °C. Using AES and XPS, we observed that Zr oxide has more fully oxidized stoichiometry than Hf oxide, irrespective of annealing temperatures. We also found that the thickness of an interfacial layer located between Hf-Zr mixed oxide and Si substrate also increases as annealing temperature increases. Especially, the thin SiO_x interfacial layer starts to form if annealing temperature increases over 700 °C, deteriorating the equivalent oxide thickness.     

A thin gold coated hydrogen heat pipe-cryogenic target for external experiments at COSY

A gravity assisted Gold coated heat pipe (GCHP) with 5-mm diameter has been developed and tested to cool a liquid hydrogen target for external beam experiments at COSY. The need for a narrow target diameter leads us to study the effect of reducing the heat pipe diameter to 5 mm instead of 7 mm, to study the effect of coating the external surface of the heat pipe by a shiny gold layer (to decrease the radiation heat load), and to study the effect of using the heat pipe without using 20 layers of‘ super-insulation around it (aluminized Mylar foil) to keep the target diameter as small as possible. The developed gold coated heat pipe was tested with 20 layers of super-insulation (WI) and without super-insulation (WOI). The operating characteristics for both conditions were compared to show the advantages and disadvantages.     

A polymer-network gel route to oxide composite nanoparticles with core/shell structure

A modified polymer-network gel route has been developed to prepare oxide composite nanoparticles with core/shell structure. The core particles, which are prepared firstly using an acrylamide gel method, are dispersed in the solution of the shell material to form a uniform suspension, and then the suspension system is gelled by the polymerization of acrylamide. The gel is calcined to remove the organic phase, consequently leading to the coating of the shell material on the core particles. The versatility of this sol-gel method in preparing core/shell nanocomposites is evidenced by the example of MgO-coated La_0.67Ca_0.33MnO₃ system. The preparation process has been discussed in detail.     

6061铝合金搅拌摩擦焊工艺窗口的研究

目的提高6061铝合金搅拌摩擦焊接头的质量,确定合适的工艺参数范围。方法设计3种不同的搅拌头进行焊接,分析接头拉伸强度与组织性能,并根据试验结果建立工艺窗口,选择合适的轴肩尺寸及工艺参数范围。结果随着轴肩尺寸减小,焊缝宽度、金属流动性、热力影响区面积均减小,在较大的焊接速度及较小的搅拌头转速下,焊缝底部出现缺陷;采用轴肩直径小的搅拌头进行焊接,在一定焊接参数范围内,焊接接头的拉伸强度得到提高;随着轴肩直径减小,焊核区晶粒组织细化,材料变形程度减小;由建立的工艺窗口可知,当轴肩尺为9 mm时,可选择的参数范围最大。结论焊接时采用小尺寸轴肩,可以在搅拌头行走速度更低、转速更大的情况下,仍然可以保持合理产热量,使接头性能得到提高。     

Cross section calculations in Glauber model: I. Core plus one-nucleon case

This paper presents a Fortran program to calculate cross sections for various reactions between composite particles in the framework of Glauber theory. The projectile nucleus is described as a core plus one valence-nucleon system. The input data needed for the calculation are the core and target densities and the nucleon-nucleon profile function. The single-particle wave function of the valence nucleon may be provided by a user or generated by the code if appropriate quantum numbers of the wave function are specified. Multiple integrations involving the valence-nucleon wave function are performed by a Monte Carlo technique with Metropolis algorithm. The program gives the total reaction cross section, the one-nucleon removal cross section, the elastic differential cross section, and the longitudinal momentum distribution of the core fragment. Sample calculations include the reactions of ^13,19C+¹²C, ¹¹Be+¹²C, ¹¹Be+⁹Be, and ⁸B+¹²C systems.     

Ti-Zr-V non-evaporable getter films: From development to large scale production for the Large Hadron Collider

Non-evaporable getter (NEG) alloys after dissolution of their native oxide layer into the bulk are able to pump most of the gases present in ultra-high vacuum systems. The dissolution process, commonly called activation, is obtained by heating in vacuum. NEG materials can be sputter-deposited as a thin film on the inner wall of a vacuum chamber, transforming it from a source of gas into an effective pump. The most significant advance in the development of NEG films was the discovery of a very low activation temperature (180 °C for 24 h heating) in a large range of compositions of the Ti-Zr-V system. This favourable property was correlated with nanometric grain size of the film (about 3 to 5 nm).In addition to pumping, NEG films lead to reduced induced gas desorption and secondary electron yields. As a consequence, Ti-Zr-V films provide the optimum solution to most of the problems encountered in vacuum systems of modern particle accelerators for high energy physics and for synchrotron radiation facilities. In the near future the most significant benchmark for Ti-Zr-V films will be the Large Hadron Collider (LHC) presently under construction at CERN, where about 6 km of beam pipe are being coated. A dedicated magnetron sputtering facility has been built to cope with the high number of vacuum chambers (about 1200) and the tight production schedule.