A Novel Method Using Flower-like Manganese Oxide Nanozymes for Colorimetric Detection of Ascorbic Acid

This paper proposes a method of utilizing a flower-like MnOx nanozyme to conduct a colorimetric detection of ascorbic acid.The nanozyme is obtained by a chain of reaction of K3[Fe(CN)6],MnSO4·H2O,polyvinyl pyrrolidone(PVP),NH4F,ethanol,and water.During the experimental process,the flower-like nanozyme is added to the mixed solution,including phosphate buffer,H2O2,and 3,3’,5,5’-tetramethylbe nzidine(TMB).The optimum reaction condition as following:pH 3.0,30μL 500mM H2O2,25μL 92 mM TMB,and 30μL 0.1mM nanozyme.Under the optimum condition,the detection range is 2-26mM,and the linear detection range is 2-20mM.

基于ESG表现和金融化的企业违约风险预警分析

文章基于2022年被首次特殊处理的40家我国A股上市公司及其对应的107家未被特殊处理的A股上市公司样本数据,利用因子分析对11个财务指标提取5个公因子,并基于ESG视角构造金融化指标,运用Logistic模型对企业违约概率进行实证检验。研究发现:1)企业的ESG表现与违约风险呈显著负相关关系;2)企业的金融化程度在一定情况下与违约风险呈显著正相关关系,尤其是反映企业在当年来自金融渠道的收益与营业总收入之比的流量指标在大多数情况下与违约风险呈显著正相关关系。3)利用聚类分析对预测因子进行聚类后,只会对模型预测效果产生轻微影响,但是对其进行聚类后,不仅方便企业对自身财务和ESG进行控制和优化,也方便投资者对投资对象违约风险的评估。这些结论为投资者在选择投资对象、企业在资产配置和战略选择以及管理当局在信息披露管理等方面提供了启示。