ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

The effects of density, resin content and hot-pressing temperature on mechanical properties of reconsolidated square material of cotton stalk were investigated by single factor test. The result showed that modulus of elasticity, bending strength and compression strength of cotton stalk reconsolidated square material gradually increased with the increase of density (0.5g/cm3, 0.6g/cm3 and 0.7g/cm3) and resin content (8％, 10％ and 12％) during the range of experiment. With the hot-pressing temperature rising, these mechanical properties increased initially（from 160℃ to 180℃）and then decreased (from 180℃ to 200℃). At other technology condition being equal, the mechanical properties of cotton stalk reconsolidated square material used phenol-formaldehyde (PF) were obviously superior to those used the melamine modified urea-formaldehyde (MUF). The mechanical properties of cotton stalk reconsolidated square material with density of 0.7g/cm3 could be equivalent to mature wood of plantation grown poplar.