This standard specifies the terms and definitions, theory, apparatus, specimens, test procedures, calcu- lation results, apparatus check and test reports, etc. of abrasion resistance at ambient temperature of refracto...This standard specifies the terms and definitions, theory, apparatus, specimens, test procedures, calcu- lation results, apparatus check and test reports, etc. of abrasion resistance at ambient temperature of refractory products.展开更多
本文主要介绍了地面数字电视广播(Digital Television Terrestrial Broadcasting,DTrB)系统,在介绍国外现有的DTIB传输标准的基础上说明清华大学数字电视传输技术研发中心提出的DMB-T(Terrestrial Digital Multi- media/Television Broa...本文主要介绍了地面数字电视广播(Digital Television Terrestrial Broadcasting,DTrB)系统,在介绍国外现有的DTIB传输标准的基础上说明清华大学数字电视传输技术研发中心提出的DMB-T(Terrestrial Digital Multi- media/Television Broadcasting)标准。DMB-T系统采用了时域同步正交频分复用(TDS-OFDM)的多载波调制方式,适用于具有多径干扰和多普勒频移的地面数字电视广播传输信道。通过比较,DMB-T具有新的关键技术和优越的性能。展开更多
文摘This standard specifies the terms and definitions, theory, apparatus, specimens, test procedures, calcu- lation results, apparatus check and test reports, etc. of abrasion resistance at ambient temperature of refractory products.
文摘本文主要介绍了地面数字电视广播(Digital Television Terrestrial Broadcasting,DTrB)系统,在介绍国外现有的DTIB传输标准的基础上说明清华大学数字电视传输技术研发中心提出的DMB-T(Terrestrial Digital Multi- media/Television Broadcasting)标准。DMB-T系统采用了时域同步正交频分复用(TDS-OFDM)的多载波调制方式,适用于具有多径干扰和多普勒频移的地面数字电视广播传输信道。通过比较,DMB-T具有新的关键技术和优越的性能。