The oxidizability-resistance of graphite products have been studied with the addition of H3PO4 and H3BO3. A available way has been found to increase the oxidizability-resistance of graphite products. The oxidizability...The oxidizability-resistance of graphite products have been studied with the addition of H3PO4 and H3BO3. A available way has been found to increase the oxidizability-resistance of graphite products. The oxidizability-resistance of graphite products rises remarkably after treating with 1% H3PO4 and 3% H3BO3. Meanwhile, the relative princi-ple has been proposed also.展开更多
水既可以隔绝空气,又可以吸热降温,是防火、灭火的绝好材料。但经过大量的煤矿现场应用及实验研究发现:很多情况下,注水不仅不能预防煤炭自燃灾害,反而易于灾害发生。为了揭示煤矿井下注水易引起煤自燃的原因,应用Gaussian09程序,采用...水既可以隔绝空气,又可以吸热降温,是防火、灭火的绝好材料。但经过大量的煤矿现场应用及实验研究发现:很多情况下,注水不仅不能预防煤炭自燃灾害,反而易于灾害发生。为了揭示煤矿井下注水易引起煤自燃的原因,应用Gaussian09程序,采用含时密度泛函理论(TD-DFT),在B3LYP/6-31G(d,p)水平上,分析水溶剂效应对煤氧化特性的影响。由计算结果可知:煤各模型的HOMO与O2的LUMO对称性相同,且能级差均小于0.4 e V,符合前线轨道理论提出的反应条件,所以煤HOMO轨道的电子将流向O2未占据的LUMO轨道,从而发生氧化反应,氧化反应剧烈时将引起煤炭自燃;当煤浸泡在水中,煤分子与水分子间将产生静电相互作用,氢键及孔洞能等相互作用,这些相互作用影响了煤分子的核外电子排布,改变了煤的前线轨道能级,煤各模型的HOMO与O2的LUMO能级差比在气相中更小,因此,被水浸泡的煤更容易发生氧化自燃。展开更多
文摘The oxidizability-resistance of graphite products have been studied with the addition of H3PO4 and H3BO3. A available way has been found to increase the oxidizability-resistance of graphite products. The oxidizability-resistance of graphite products rises remarkably after treating with 1% H3PO4 and 3% H3BO3. Meanwhile, the relative princi-ple has been proposed also.
文摘水既可以隔绝空气,又可以吸热降温,是防火、灭火的绝好材料。但经过大量的煤矿现场应用及实验研究发现:很多情况下,注水不仅不能预防煤炭自燃灾害,反而易于灾害发生。为了揭示煤矿井下注水易引起煤自燃的原因,应用Gaussian09程序,采用含时密度泛函理论(TD-DFT),在B3LYP/6-31G(d,p)水平上,分析水溶剂效应对煤氧化特性的影响。由计算结果可知:煤各模型的HOMO与O2的LUMO对称性相同,且能级差均小于0.4 e V,符合前线轨道理论提出的反应条件,所以煤HOMO轨道的电子将流向O2未占据的LUMO轨道,从而发生氧化反应,氧化反应剧烈时将引起煤炭自燃;当煤浸泡在水中,煤分子与水分子间将产生静电相互作用,氢键及孔洞能等相互作用,这些相互作用影响了煤分子的核外电子排布,改变了煤的前线轨道能级,煤各模型的HOMO与O2的LUMO能级差比在气相中更小,因此,被水浸泡的煤更容易发生氧化自燃。
