含钡合金的生产及其对钢液脱氧行为的研究

介绍了含钡合金的生产状况。在MoSi2炉上对钢管钢进行了含钡合金脱氧行为的研究，然后在150tLF／VD精炼设备上进行了使用含钡合金的工业试验。研究中主要选取SiAlBa、SiCaBa、SiAlBaCa、SiAlBaCaSr及用于钙处理的SiCa包芯线，并选用Al和FeSiAl作为对比脱氧剂，分别考察了实验室条件下和实际生产过程中，采用钡系合金对钢液脱氧的全氧含量，脱氧产物的分布、尺寸和形貌，探讨了钡系合金脱氧和对夹杂物的变质作用的机理。     

自蔓延高温合成TiNi多孔体合金

为了开发新型的生体材料，本文对自蔓延高温合成TiNi多孔体合金——人造骨材料进行了研究。以单质钛粉和镍粉作原料，在氩气保护条件下，采用预热点燃模式和热爆模式制得了不同形态的多孔TiNi形状记忆合金。采用SEM和XRD分析了样品的孔洞特征和相组成，测试了其力学性能，并研究了合成条件参数与样品表面形貌和孔隙状态之间的关系。结果表明，用SHS法制备TiNi多孔体合金是可行的。     

A Hermitian Box-scheme for One-dimensional Elliptic Equations – Application to Problems with High Contrasts in the Ellipticity

We introduce a new box-scheme, called ``hermitian box-scheme' on the model of the one-dimensional Poisson problem. The scheme combines features of the box-scheme of Keller, [20], [13], with the hermitian approximation of the gradient on a compact stencil, which is characteristic of compact schemes, [9], [21]. The resulting scheme is proved to be 4th order accurate for the primitive unknown u and its gradient p. The proved convergence rate is 1.5 for (u,p) in the discrete L ² norm. The connection with a non standard mixed finite element method is given. Finally, numerical results are displayed on pertinent 1-D elliptic problems with high contrasts in the ellipticity, showing in practice convergence rates ranging from 1 to 2.5 in the discrete H ¹ norm. This work has been performed with the support of the GDR MOMAS, (ANDRA, CEA, EDF, BRGM and CNRS): Modélisation pour le stockage des déchets radioactifs. The author thanks especially A. Bourgeat for his encouragements and his interest in this work.     

Sorption of Acid Green 25 on chitosan: Influence of experimental parameters on uptake kinetics and sorption isotherms

Acid Green 25, which is a diazoic dye bearing two sulfonic groups, is efficiently sorbed on chitosan. The protonation of chitosan may explain the electrostatic attraction of this anionic dye and that its optimum pH is close to 3. Preliminary protonation of amine groups (obtained by contact with a sulfuric acid solution) reduced the variation of solution pH following sorbent addition but significantly reduced sorption performance: the maximum sorption capacity of raw chitosan, 525 mg dye/g (0.84 mmol dye/g), was halved by acidic preconditioning. The acidic conditioning also reduced the kinetic rate—the time necessary to reach equilibrium increased up to threefold depending on the experimental conditions. The size of sorbent particles influenced sorption kinetics and equilibrium because of resistance to intraparticle diffusion, but the sorption appeared to occur not only at the surface of the sorbent but also in the intraparticle network of the polymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1073–1080, 2003     

Effect of heat treatments on tensile properties and microstructures of wrought Mg−Zn−Zr-RE alloys

The effect of heat treatments on the tensile properties and microstructures of wrought Mg–Zn–Zr-Rare earth alloys MB25 and MB26 have been studied in this paper. It was shown that the homogenization of the cast ingots decreased the strength of the extruded bars because some grain boundary phases were dissolved during the process of this treatment, while the ageing treatment of the extruded bars increased the strength due to the dispersive precipitation of MgZn₂ phase. The quenching + ageing treatments of the extruded bars decreases the strength and plasticity because of the growing up of the grains.Abbreviations ED electron diffraction - GB grain boundary - RE rare earth - TEM transmission electron microscope     

Structure of rapidly solidified aluminum alloys

This paper is a summary of an extensive research program carried out by the authors on the structure of rapidly solidified aluminum alloys; and a comparison with the work of others also involved in this field. The paper discusses the changes in the dendritic and non-dendritic structure of the matrix at cooling rates from 10^–3 to 10¹⁰ K/s and discusses the hetergeneity of the structure caused by interdendritic-segretion during solidification.     

镁基储氢材料的研究进展

本文回顾和总结了近几十年来，特别是近十年来镁基储氢材料的发展情况，重点综述了机械合金化Mg-Ni2合金体系的研究情况及其近期的进展，从储氢材料成份及配比，制造工艺改进以及材料的组织结构对材料性能的影响等各方面进行一定的分析和归纳，对储氢材料研究中出现的问题以及今后的发展方向都作了探讨。     

铝锂合金力学性能的各向异性

针对当前困扰铝锂合金实际应用的各向异性问题，概述关于铝锂合金中各向异性的表现规律，产生机理及对于降低各向异性所采用的方法等方面的研究现状和进展，对铝锂合金各向异性表现与微观组织结构的关系以及目前克服各向异性所采用方法的局限性进行分析。就此提出，若彻底解决这一问题则必须采用更先进的合金化方法及热加工工艺，研制新一代铝锂合金的观点和研究方向。     

An investigation of pore cracking in titanium welds

Two welded Ti-6A1-4V pressure vessels leaked prematurely in service. The leaks were caused by cracks emanating from weld porosity. The cracks originated during fabrication, with subsequent growth in service leading to the formation of the leak paths. Pore cracking is thought to be caused by a mechanism that involves both sustained-load and cyclic contributions, with the former being the more prominent. It is shown that the tendency for cracking is influenced by pore position and that pore size is not a deciding factor in that regard. The factors that govern pore cracking are discussed, and the possible role of interstitial embrittlement is assessed.     

Brandschutz; subjektiv-?ffentliche Nachbarrechte

Nachbarn kommt kein Mitspracherecht dahingehend zu, dass die Zufahrt für Einsatzfahrzeuge der Feuerwehr gew?hrleistet sein müsste.