document.write('<br><span style="font-size:15px">上一篇</span> <a href=/shtmlnewsfiles/ecomnews/467/2013/20132041316438004.shtml  target="_blank">流体流动原理</a><br><span style="font-size:15px">下一篇</span> <a href=/shtmlnewsfiles/ecomnews/467/2013/201320414574727666.shtml  target="_blank">流体的特性</a>')