TV2.0时代传统电视的变革及其发展趋势研究

TV2.0是一种全新的电视媒体信息传播理念,它强调收看形式或节目内容的互动性,使观众在看电视的过程中获得参与和分享,达到全新的个人体验,为此探讨了TV2.0时代传统电视的变革及其发展趋势。     

流媒体技术在远程教育中的应用

随着Internet技术及应用的不断发展,大数据量多媒体信息在网上的传输显得越来越重要和必须,流媒体技术(Streaming Media Technology)以其独有和丰富的特性深受远程教育工作者的青睐。本文主要阐述了流媒体技术的基础、流媒体系统的构成、流媒体的文件格式、流媒体的主要技术方案和流媒体技术在远程教育中的应用,以期对流媒体技术与现代远程教育的开展作一些初步探讨。     

Magnetic properties and magnetocaloric effect in RE55Co30Al10Si5 (RE = Er and Tm) amorphous ribbons

The magnetic and magnetocaloric effects (MCE) of the amorphous $RE_{55}$Co$_{30}$Al$_{10}$Si$_{5}$ ($RE={\rm Er}$ and Tm) ribbons were systematically investigated in this paper. Compounds with $R ={\rm Er}$ and Tm undergo a second-order magnetic phase transition from ferromagnetic (FM) to paramagnetic (PM) around Curie temperature $T_{\rm C} \sim 9.3$ K and 3 K, respectively. For Er$_{55}$Co$_{30}$Al$_{10}$Si$_{5}$ compound, an obvious magnetic hysteresis and thermal hysteresis were observed at low field below 6 K, possibly due to spin-glass behavior. Under the field change of 0 T-5 T, the maximum values of magnetic entropy change ($-\Delta S_{\rm M}^{\rm max}$) reach as high as 15.6 J/kg$\cdot$K and 15.7 J/kg$\cdot$K for Er$_{55}$Co$_{30}$Al$_{10}$Si$_{5}$ and Tm$_{55}$Co$_{30}$Al$_{10}$Si$_{5}$ compounds, corresponding refrigerant capacity (RC) values are estimated as 303 J/kg and 189 J/kg, respectively. The large MCE makes amorphous $RE_{55}$Co$_{30}$Al$_{10}$Si$_{5 }$ ($RE={\rm Er}$ and Tm) alloys become very attractive magnetic refrigeration materials in the low-temperature region.