After repeated boiling and vacuum-pressure conditioning respectively, the bond strengths of larch plywood with different thicknesses were examined and compared.
对分别用反复煮沸和减压加压方式处理的落叶松结构用胶合板进行了胶合强度性能检测和对比。
methylhydroquinone was prepared by oxidation of o-methyl aniline and manganese(Ⅳ) oxide in sulfuric acid and negative-pressure reduction using iron as reducer under neutral condition.
以邻甲基苯胺为原料,在硫酸介质中与二氧化锰氧化得到邻甲基苯醌,再在中性条件下经铁粉负压还原合成甲基对苯二酚 以负压还原工艺替代常压还原,所用蒸汽量大为减少,极大地降低了能耗,提高了收率,从而降低了生产成本,且对产品的质量无影
