高效液相色谱法测定熏烧烤肉制品中苯并(a)芘的不确定度评定

本文按照《食品安全国家标准食品中苯并(a)芘的测定》(GB 5009.27—2016)检测熏烧烤肉制品中苯并(a)芘的含量,并参照《测量不确定度评定与表示》(JJF 1059.1—2012),建立测量模型,对实验结果的不确定度来源进行分析和评定。结果显示,熏烧烤肉制品中苯并(a)芘含量为2.708μg·kg-1时,其扩展不确定度为0.215μg·kg-1(k=2),标准曲线拟合过程引入的不确定度最大,其次为重复性测定,需要在以后实验中保证规范操作,以减小不确定度,保证检验结果准确可靠。     

含乳饮料中蛋白质含量测定结果的不确定度评定

对凯氏定氮法测定含乳饮料中蛋白质含量进行测量不确定度来源分析,结果的适用性给出合理的建议。依据JJF 1059.1—2012,分析测量过程中影响不确定度的因素,进行评估合成。结果表明,空白测定和测量重复性是主要的不确度来源,含乳饮料中蛋白质结果为1.53 g/100 g时,扩展不确定度为0.13 g/100 g,因此蛋白质含量测定结果可表示为(1.53±0.13)g/100 g(k=2)。     

经济政策不确定性与商业信用融资——基于商业信用网络位置视角的分析

以2000—2022年沪深A股上市公司数据为样本,研究经济政策不确定性对商业信用融资的影响及商业信用网络位置的调节效应。研究发现,面对经济政策不确定性时,企业会选择提升商业信用融资,企业的商业信用网络中心位置能够帮助企业获得更多性商业信用融资。进一步研究表明,面对经济政策不确定性时,商业信用网络中心位置的企业是通过提升企业的议价能力与系统性风险地位进而提升商业信用融资的。面对经济政策不确定性提升,商业信用网络中心位置会缓解企业对银行信用的依赖,但当企业自身能够获得银行信用青睐时,商业信用网络中心位置会进一步提升企业的商业信用。因此建议企业在经济政策不确定高时充分融入商业信用网络,以商业信用资源弥补企业的银行信用不足,同时监管当局需要合理引导优化金融资源配置,避免商业信用与银行信用资源的过度倾斜。     

CVP under Uncertainty and the Manager's Utility Function Revisited

This paper re-examines the model of Kim, Abdolmohammada, and Klein (KAK, 1996) in which owners of a firm delegate the production decision to a risk-averse manager. Conflict of interest between the owners and the manager emerges as the latter maximizes the expected utility of his/her own wealth rather than that of the firm's profits. This paper shows that the results of KAK on the expected contribution margin and the excess return on the risky asset are flawed. Furthermore, while KAK study the effects of delegating the production decision to the manager on the firm's optimal output based on the mean-variance analysis, this paper derives parallel results within utility functions exhibiting constant absolute risk aversion and any arbitrary probability distribution functions.     

Collective action and market formation: An integrative framework

Research Summary : While extant research recognizes the importance of collective action for market formation, it provides little understanding about when and to what extent collective action is important. In this article, we develop a novel theoretical framework detailing what collective action problems and solutions arise in market formation and under what conditions. Our framework centers on the development of market infrastructure with three key factors that influence the nature and extent of collective action problems: perceived returns to contributions, excludability, and contribution substitutability. We apply our framework to diverse market formation contexts and derive a set of attendant propositions. Finally, we show how collective action problems and solutions evolve during market formation efforts and discuss how our framework contributes to strategic management, entrepreneurship, and organization literatures. Managerial Summary : This article lays out the key considerations that players operating in new markets should contemplate when making nontrivial investments in those spaces. As collective action problems can thwart efforts to establish new markets, we ask: When and under what conditions should market players collaborate rather than act independently? And if players collaborate, how should they coordinate to establish a new market? To address these research questions, we develop a novel generalizable framework of collective action in market formation. Our framework assesses the presence and type of collective action problems that hinder market formation and identifies potential solutions tied to those collective action problems.     

The role of information sources and image on the intention to visit a medical tourism destination: a cross-cultural analysis

This paper intends to analyze: 1) how information sources, eWOM, and image influence the intention to visit a medical tourism destination;2) the moderating role of culture and 3) cross-cultural differences based on Hofstede’s individualism and uncertainty avoidance. A total of 534 responses were collected using a panel of internet users from six different countries and data were analyzed using structural equation modeling and a series of t-tests. The results show that information sources influence cognitive impressions and in conjunction with overall image and medical cognitive image influence the intention to visit a medical tourism destination. Furthermore, individualism and uncertainty avoidance have a moderating effect among these variables and cross-cultural differences exist in the degree of importance given to information sources, eWOM, image perceptions, and intention.     

A wavelet analysis for exploring the relationship between economic policy uncertainty and tourist footfalls in the USA

We attempt to establish the relationship between Economic Policy Uncertainty (EPU) and international tourist footfalls in the USA. In the first stage, we investigate the influence of country-specific EPU and global EPU on tourist footfalls. Since, these two are overlapping in nature, in the second stage, we study the isolated influence of country-specific EPU on footfalls by eliminating the influence of global EPU and vice versa. We consider a study period spanning over January 1997 to April 2017. To capture the variations in the relationship at different time dimensions, we apply wavelet-based techniques. We observe the following: (a) the impact of policy uncertainty shock has a little immediate impact on tourist footfalls, (b) medium to long-run shocks persist due to occurrence of major undesirable economic events, and (c) the influence of domestic (country-specific) EPU is dominant in comparison to global EPU for the USA.     

经济政策不确定性对我国股市波动的影响——基于2007—2019年上证指数的实证分析

股票市场的波动受到宏观经济政策的影响。本文研究2007年1月—2019年10月的月度数据,其结论如下:(1)主效应的经济政策不确定性越高,我国股市波动率越低;(2)在惯性因素上我国股市波动率会显著受到滞后波动率的影响;(3)在结构性断点上我国股市波动率在2008年金融危机和2010年融资融券交易处存在结构性断点;(4)在交互效应上2010年融资融券交易制度的建立降低了股市波动率对于经济政策不确定性的敏感程度。本文的研究结论拓展了研究边界,为宏观政策制定及资本市场投资提供了思路参考。     

企业对外直接投资中的邻居效应:理论机制分析及实证检验

随着对外开放的扩大和深化,近年来中国企业对外投资增长迅速。企业全球配置生产会面临比国内生产更多的不确定性和风险,为提高投资效率,企业需从多方面获取对外直接投资的知识,包括从邻居企业获取信息和经验等。从理论机制上分析邻居效应产生的原因,包括知识溢出、竞争效应、信号传递、产业链带动等途径。在此基础上,构建2002-2013年期间详细的中国工业企业投资数据,实证检验企业对外直接投资中的邻居效应及其产生机制。结果表明:我国企业对外直接投资中确实存在邻居效应,即邻居企业的对外直接投资行为会通过多种方式促进企业"走出去"。进一步地,在省份范围内的邻居效应影响较弱;在行业内部以及细分投资市场的邻居效应影响较强。因此,应利用邻居企业的对外直接投资信息和经验,发挥企业之间的学习效应,提高我国企业对外直接投资成功率。     

葵花籽中水分含量测定不确定度评定

依据《食品安全国家标准食品中水分的测定》(GB 5009.3-2016)中第一法测定葵花籽中的水分。根据方法计算公式建立相应的数学模型,对葵花籽中水分的来源进行全面、细致的分析,通过对影响葵花籽中水分测定结果的4个不确定度分量μA(x)、μ(m1)、μ(m2)、μ(m3)进行量化分析,最后在实验中得出所测定葵花籽水分含量为6.82g/100g时,其扩展不确定度为0.06g/100g(k=2),进而得到了影响合成不确定度最主要的因素为μA(x),进一步保证了检测结果的准确性和稳定性。