The set of finite group actions (up to equivalence) which operate on a prism manifold M, preserve a Heegaard Klein bottle and have a fixed orbifold quotient type, form a partially ordered set. We describe the partial ...The set of finite group actions (up to equivalence) which operate on a prism manifold M, preserve a Heegaard Klein bottle and have a fixed orbifold quotient type, form a partially ordered set. We describe the partial ordering of these actions by relating them to certain sets of ordered pairs of integers. There are seven possible orbifold quotient types, and for any fixed quotient type we show that the partially ordered set is isomorphic to a union of distributive lattices of a certain type. We give necessary and sufficent conditions, for these partially ordered sets to be isomorphic and to be a union of Boolean algebras.展开更多
为探究蒸汽处理对黟县黑毛茶陈化的作用,本研究通过感官审评结合顶空固相微萃取-气相色谱-质谱联用技术、氨基酸分析仪及高效液相分析仪分析了蒸汽处理对黑毛茶风味品质的影响。结果表明,蒸汽处理能够加快黑毛茶陈化,促进陈香和醇厚风...为探究蒸汽处理对黟县黑毛茶陈化的作用,本研究通过感官审评结合顶空固相微萃取-气相色谱-质谱联用技术、氨基酸分析仪及高效液相分析仪分析了蒸汽处理对黑毛茶风味品质的影响。结果表明,蒸汽处理能够加快黑毛茶陈化,促进陈香和醇厚风味的生成。感官评价显示,第三次蒸汽处理后风味最佳。挥发性物质分析显示,蒸汽处理后挥发性物质总量先降后增,在第三、第四次蒸汽处理后香气总量较高,分别为9113.62、10222.82μg/kg;蒸汽处理后呈现花香、甜香风味的壬醛、反-2-辛烯醛、二氢芳樟醇大量生成,而芳樟醇、香叶醇及二甲基硫含量则显著减少(P<0.05)。滋味物质分析显示,蒸汽处理后,样品中儿茶素总量和表型儿茶素(表没食子儿茶素、表没食子酸儿茶素没食子酸酯)含量显著降低(P<0.05),而没食子酸和非表型的儿茶素、没食子儿茶素没食子酸酯含量则增加;游离氨基酸总量在第三次蒸汽处理后增加最为显著(P<0.05),尤其是茶氨酸增加了13.1%。正交偏最小二乘判别分析模型(Orthogonal partial least squares-discriminant analysis,OPLS-DA)显示不同蒸汽处理的黑毛茶差异明显,结合变量投影重要性(Variable important for the projection,VIP)、香气活度值(Odor active value,OAV)、滋味活度值(Dose-over-threshold factors,DOT),筛选出壬醛、癸醛、二甲基硫、1-辛烯-3-酮、反-2-辛烯醛、正己醛、没食子儿茶素、表没食子儿茶素没食子酸酯、表没食子儿茶素、茶氨酸等物质,是影响样品间香气与滋味变化的重要因子。本研究结果为加快黟县黑毛茶的陈化提供了一种可用的新思路及参考依据。展开更多
文摘The set of finite group actions (up to equivalence) which operate on a prism manifold M, preserve a Heegaard Klein bottle and have a fixed orbifold quotient type, form a partially ordered set. We describe the partial ordering of these actions by relating them to certain sets of ordered pairs of integers. There are seven possible orbifold quotient types, and for any fixed quotient type we show that the partially ordered set is isomorphic to a union of distributive lattices of a certain type. We give necessary and sufficent conditions, for these partially ordered sets to be isomorphic and to be a union of Boolean algebras.
文摘为探究蒸汽处理对黟县黑毛茶陈化的作用,本研究通过感官审评结合顶空固相微萃取-气相色谱-质谱联用技术、氨基酸分析仪及高效液相分析仪分析了蒸汽处理对黑毛茶风味品质的影响。结果表明,蒸汽处理能够加快黑毛茶陈化,促进陈香和醇厚风味的生成。感官评价显示,第三次蒸汽处理后风味最佳。挥发性物质分析显示,蒸汽处理后挥发性物质总量先降后增,在第三、第四次蒸汽处理后香气总量较高,分别为9113.62、10222.82μg/kg;蒸汽处理后呈现花香、甜香风味的壬醛、反-2-辛烯醛、二氢芳樟醇大量生成,而芳樟醇、香叶醇及二甲基硫含量则显著减少(P<0.05)。滋味物质分析显示,蒸汽处理后,样品中儿茶素总量和表型儿茶素(表没食子儿茶素、表没食子酸儿茶素没食子酸酯)含量显著降低(P<0.05),而没食子酸和非表型的儿茶素、没食子儿茶素没食子酸酯含量则增加;游离氨基酸总量在第三次蒸汽处理后增加最为显著(P<0.05),尤其是茶氨酸增加了13.1%。正交偏最小二乘判别分析模型(Orthogonal partial least squares-discriminant analysis,OPLS-DA)显示不同蒸汽处理的黑毛茶差异明显,结合变量投影重要性(Variable important for the projection,VIP)、香气活度值(Odor active value,OAV)、滋味活度值(Dose-over-threshold factors,DOT),筛选出壬醛、癸醛、二甲基硫、1-辛烯-3-酮、反-2-辛烯醛、正己醛、没食子儿茶素、表没食子儿茶素没食子酸酯、表没食子儿茶素、茶氨酸等物质,是影响样品间香气与滋味变化的重要因子。本研究结果为加快黟县黑毛茶的陈化提供了一种可用的新思路及参考依据。
