锌配合物的绿色合成与表征是结合配合物基础知识和当前科学研究热点设计改进的一个综合性实验。本文以水为溶剂,以对氨基苯磺酸(4-ABS)和ZnO为主要原料,直接法制备得到一种三维网状配合物。对该配合物进行单晶X射线衍射、红外光谱、热...锌配合物的绿色合成与表征是结合配合物基础知识和当前科学研究热点设计改进的一个综合性实验。本文以水为溶剂,以对氨基苯磺酸(4-ABS)和ZnO为主要原料,直接法制备得到一种三维网状配合物。对该配合物进行单晶X射线衍射、红外光谱、热重分析、紫外以及荧光光谱等结构表征,并采用Materials Studio (MS)软件的CASTEP模块,对配合物的几何构型进行优化,从原子水平上进一步佐证配合物的最优结构及稳定化能。该实验过程包含配合物制备、蒸发浓缩、减压过滤、单晶培养、紫外及荧光光谱测试、热重分析、理论计算等,整个教学过程综合性及可操作性较强。同时,该实验把绿色合成融入到实验方案设计和实施的全过程,使学生树立节能环保的理念,激发学生探究真知的兴趣和热情,使其在加深理解配位化学基础知识的同时,获得了相关前沿热点知识,对培养学生创新思维、科学研究能力和综合素质具有十分重要的意义。展开更多
This research looks at any relevance between Altman’s Z-score and the stock market performance of airline companies in the United States(US).Nearly a thousand pieces of data on various aspects of operation and financ...This research looks at any relevance between Altman’s Z-score and the stock market performance of airline companies in the United States(US).Nearly a thousand pieces of data on various aspects of operation and financial status from 81 airline companies in the US are available.Additionally,stock return is used as an indicator of firm stock performance in this paper.In order to satisfy the purpose of determining the relationship between Z-score and stock performance as well as what may be inferred from high stock returns with regard to Z-score,two different regression processes are carried out.The first regression tests the relationship between Z-score and stock return,while the second regression examines whether there is a difference in Z-scores between well-performing airline companies and poorly performing ones using dummy variables.The results reveal that there is a significant positive correlation between the Z-scores of US airline companies and their stock performance;besides,high stock returns potentially imply relatively high Z-scores and vice versa.Therefore,one of the crucial steps that US airline companies must make is to strengthen their balance sheets in order to draw investors to make investments in their businesses.展开更多
文摘锌配合物的绿色合成与表征是结合配合物基础知识和当前科学研究热点设计改进的一个综合性实验。本文以水为溶剂,以对氨基苯磺酸(4-ABS)和ZnO为主要原料,直接法制备得到一种三维网状配合物。对该配合物进行单晶X射线衍射、红外光谱、热重分析、紫外以及荧光光谱等结构表征,并采用Materials Studio (MS)软件的CASTEP模块,对配合物的几何构型进行优化,从原子水平上进一步佐证配合物的最优结构及稳定化能。该实验过程包含配合物制备、蒸发浓缩、减压过滤、单晶培养、紫外及荧光光谱测试、热重分析、理论计算等,整个教学过程综合性及可操作性较强。同时,该实验把绿色合成融入到实验方案设计和实施的全过程,使学生树立节能环保的理念,激发学生探究真知的兴趣和热情,使其在加深理解配位化学基础知识的同时,获得了相关前沿热点知识,对培养学生创新思维、科学研究能力和综合素质具有十分重要的意义。
文摘This research looks at any relevance between Altman’s Z-score and the stock market performance of airline companies in the United States(US).Nearly a thousand pieces of data on various aspects of operation and financial status from 81 airline companies in the US are available.Additionally,stock return is used as an indicator of firm stock performance in this paper.In order to satisfy the purpose of determining the relationship between Z-score and stock performance as well as what may be inferred from high stock returns with regard to Z-score,two different regression processes are carried out.The first regression tests the relationship between Z-score and stock return,while the second regression examines whether there is a difference in Z-scores between well-performing airline companies and poorly performing ones using dummy variables.The results reveal that there is a significant positive correlation between the Z-scores of US airline companies and their stock performance;besides,high stock returns potentially imply relatively high Z-scores and vice versa.Therefore,one of the crucial steps that US airline companies must make is to strengthen their balance sheets in order to draw investors to make investments in their businesses.
