中大機構典藏-NCU Institutional Repository-提供博碩士論文、考古題、期刊論文、研究計畫等下載:Item 987654321/26527
English  |  正體中文  |  简体中文  |  全文笔数/总笔数 : 80990/80990 (100%)
造访人次 : 41652764      在线人数 : 1679
RC Version 7.0 © Powered By DSPACE, MIT. Enhanced by NTU Library IR team.
搜寻范围 查询小技巧:
  • 您可在西文检索词汇前后加上"双引号",以获取较精准的检索结果
  • 若欲以作者姓名搜寻,建议至进阶搜寻限定作者字段,可获得较完整数据
  • 进阶搜寻


    jsp.display-item.identifier=請使用永久網址來引用或連結此文件: http://ir.lib.ncu.edu.tw/handle/987654321/26527


    题名: Surface fractal dimensions of alumina and aluminum borate from nitrogen isotherms
    作者: Lee,CK;Tsay,CS
    贡献者: 化學工程與材料工程學系
    关键词: POROUS SILICA-GELS;ADSORPTION-ISOTHERM;CARBON-BLACKS;NONINTEGER DIMENSIONS;CHEMISTRY;ROUGHNESS;FIBERS;FILMS
    日期: 1998
    上传时间: 2010-06-29 17:30:07 (UTC+8)
    出版者: 中央大學
    摘要: The effects of calcination temperature on the surface roughness of alumina and aluminum borate samples, prepared by the coprecipitation method and low-water sol-gel processes, were investigated by fractal analysis of their nitrogen adsorption isotherms. The surface fractal dimension D was calculated from their nitrogen isotherms using both the fractal isotherm equations derived from the FHH (Frenkel-Halsay-Hill) theory and the recently proposed Neimark equation based on thermodynamics. It was found that for samples calcined from 500 to 1100 degrees C, the D values evaluated using fractal FHH equation were nearly constant (2.5-2.6) despite a large reduction of the BET surface area and pore volume. Only after a 1250 degrees C calcination, when the alpha-alumina crystalline phase starts to sinter, was there a slightly larger change of the surface fractal dimension. On the other hand, Neimark's method suggested that thermal effects induce an enormous change on surface roughness of examined samples. The discrepancy of D values obtained with the above two methods was discussed.
    關聯: JOURNAL OF PHYSICAL CHEMISTRY B
    显示于类别:[化學工程與材料工程研究所] 期刊論文

    文件中的档案:

    档案 描述 大小格式浏览次数
    index.html0KbHTML348检视/开启


    在NCUIR中所有的数据项都受到原著作权保护.

    社群 sharing

    ::: Copyright National Central University. | 國立中央大學圖書館版權所有 | 收藏本站 | 設為首頁 | 最佳瀏覽畫面: 1024*768 | 建站日期:8-24-2009 :::
    DSpace Software Copyright © 2002-2004  MIT &  Hewlett-Packard  /   Enhanced by   NTU Library IR team Copyright ©   - 隱私權政策聲明