供应链集中度与成本结构

企业的成本结构会影响企业通过经营实现利润的能力。企业进行成本结构决策时需要综合考虑各种经营和环境因素，其中客户和供应商集中度对于企业来说是一个关键的环境因素，但现有文献很少研究供应链集中度和公司成本结构之间的潜在关系。利用2012至2016年中国制造业上市公司的成本数据，发现制造商的客户集中度和其成本弹性之间存在正相关关系，并且随着客户议价能力提升，客户集中度高的公司的成本结构灵活性被削弱；随着供应商的集中，下游制造商的变动成本比上固定成本的比值在下降，成本刚性在加强。随着供应商行业议价能力提升，供应商集中度和下游客户成本刚性结构之间的正面关系被削弱。供应链集中度和议价能力是企业成本结构决策的决定因素。     

大同煤田同忻矿瓦斯地质特征及突出危险性预测

以大同煤田同忻矿为研究对象，以矿井基础地质资料为基础，共采集62口钻井共214个瓦斯气样，以实验测试为手段，以理论分析为方法，得出了瓦斯气样成分特征；划分了各个煤层的瓦斯带类型；分析了断裂、褶皱、陷落柱、埋深、岩浆侵入、煤化程度等因素对瓦斯赋存的影响；探究了各因素的影响机理；并预测了瓦斯突出危险性。结果显示：瓦斯成分以N2、CH4和CO2为主，山4#煤为N2-CH4带和N2带，2#煤层中包括N2-CH4带和N2带，3-5#煤层中包括N2-CH4带、N2带和CO2-N2带，8#煤层中包括N2-CH4带和N2带，9#煤层中包括N2-CH4带和N2带，将矿井鉴定为高瓦斯矿井；研究区断裂性质多为正断层，利于瓦斯气体的垂向运移和散失；向斜轴部、背斜鞍部、鼻状构造的倾斜端及“S”型背斜转折端等构造部位易于瓦斯的富集保存；封闭性陷落柱为瓦斯赋存提供储集空间，而与导水裂隙带联通的陷落柱则有助于瓦斯气体的散失；瓦斯含量与煤层埋深呈正相关关系，与岩浆侵入区煤样挥发分呈明显负相关关系，而无岩浆岩区，挥发分与瓦斯含量无明显相关性，煤层埋深越大，突出危险性越高；瓦斯突出危险性预测结果显示研究区突出危险性较小。     

The role of salespeople in industrial servitization: How to manage diminishing profit returns from salespeople’s increasing industrial service shares

Business-to-business companies often differentiate themselves from competitors by complementing goods with services. While extant literature on servitization points to substantial benefits for companies and underscores the importance of the sales force for successful servitization, it has rarely empirically investigated the negative effects of and barriers to effective selling of servitized offerings at the salesperson level. Drawing on transaction cost theory, we propose that with rising service shares, the specificity of offers and transaction costs grow, partially offsetting the financial benefits. We derive four salesperson factors that moderate the effect of salespeople’s industrial service share on salespeople’s profit. These factors pertain to the extent to which salespeople individualize offers and effectively manage offers’ specificity (adaptiveness, customer valuation skills, experience). We test our conceptualization with data from 220 salespeople and company records. The results are robust to endogeneity and show that service share has a diminishing positive effect on salesperson profit. While salespersons’ offer individualization enforces this harmful effect, salesperson adaptiveness and customer valuation skills show beneficial moderating effects. This study provides valuable insights for researchers and managers into the role of the sales force in servitization and into salesperson factors conducive to realizing the full profit potential of servitized offerings.     

公路工程机械设备使用效率的影响因素与策略分析

论文主要对公路工程项目中机械设备使用效率的影响因素及应对策略进行研究,以供相关专业人士进行参考和借鉴。     

Investor attention,ETF returns,and country-specific factors

Using the data of 47 single-country exchange-traded funds (ETFs) traded in the U.S. from 36 countries during 2004–2017, this research examines the impact of investor attention proxied by Google Search Volume Index and home country-specific factors on different quantile of their returns. Evidence first shows that compared with U.S. investor attention, home country investor attention largely correlates with low to medium ETF returns, supporting the attention-induced price pressure hypothesis. Second, home country-specific factors significantly affect ETF returns at different conditional quantiles. We also find that investors prefer investing in a country with strong similarity to that of the U.S., supporting the cross-country information asymmetry hypothesis. Third, an intervening effect of home country-specific factors exists on the relationship between U.S. investor attention and ETF returns. These findings should help government authorities find appropriate strategies to attract foreign investment and upgrade the value of their capital market as well as provide a reference on efficiency for equity investors.     

新经济地理学框架下跨国公司区位选择因素分析

中国作为全球最大货物贸易国和最大外汇储备国,许多跨国公司纷纷来华投资。虽然受疫情的影响,在世界经济出现严重衰退和部分地区出现暂时停摆现象,但在华投资势头强劲,总额占世界首位。区位选择与对外直接投资之间存在着不可分离的关系,是跨国公司在海外投资时必须考虑的重要环节。良好地利用外资可以促进我国在经济上的国际交流,拉动区域经济增长和协调发展,所以研究跨国公司在中国选址时的参考因素具有实质意义。     

基于CiteSpace的研发效率的研究热点及演变趋势可视化分析

基于中国知网上2003—2018年以研发效率为主题的学术期刊,运用CiteSpace软件,通过共现关键词、聚类分析、突现词演进等对研发效率展开可视化的科学计量分析,揭示15年间的研发效率研究热点及其演进的过程,探究研发效率未来发展趋势.研究发现,关键词的研究较为紧密,研发效率整体发展呈现出3个阶段,未来"研发创新"和"技术创新"依旧是前沿热点,但机构和学者之间缺乏交流合作.     

Financial performances,entrepreneurial factors and coping strategy to survive in the COVID-19 pandemic: case of Vietnam

Vietnam has been one of a few countries that successfully contained the COVID-19 pandemic. However, aggressive measurements against the pandemic were at the expense of economic activities and companies’ financial performances. This cross-sectional study uses a survey of 672 companies in Vietnam and the logistic regression model to explore companies’ coping strategy choices based on their degree of financial distress, companies’ profiles, entrepreneurial factors, and the interactions between them. The results suggest that companies predominantly selected cost-cutting strategies to deal with the economic shutdown. However, the interactions between financial and entrepreneurial factors could significantly increase the likelihood of selecting growth-focused strategies. Besides, when facing a global pandemic such as COVID-19, managers’ perceptions about the spillover effects of global risks were much more impactful than local risks on companies’ coping strategy selections. This paper can help to inform managers to better deal with the aftermath of the COVID-19 outbreak.     

Time-varying comovement and changes of comovement structure in the Chinese stock market: A causal network method

The driving force for the comovement in stock returns is a long-standing debate between classical asset pricing theory and behavioral finance theory. It has become critically important recently for understanding systemic risk and risk contagion in the market. In this study, we propose complex networks enabled new methods to measure the causal comovement of individual stocks and the comovement structure of the market, which facilitate the examination of all kinds of hypotheses of comovement theories in a unified framework. Using a sample of the Chinese stock market from Jan. 1, 2006 to Dec. 31, 2016, we find that the degree of comovement generally intensifies over time, with a drastic increase from 2011 to 2015, while the comovement structure of the market changes with different market situations. Most importantly, our study reveals the driving force of causal comovement among individual stocks; that is, sentiment-based factors related to the market index indeed induce excess causal comovement in returns beyond that can be justified by fundamental factors including beta coefficient, book-to-market ratio, liquidity, profitability and volatility. Our study also reveals the determinants of comovement structure, which are attributable to the change of investors' behaviors in different periods. It turns out that investors in the Chinese stock market care about risk-return relationship in normal periods, while they seem to care only about risk in crisis periods.     

萤石矿研究综述

从矿床类型、控矿因素、成矿物质来源及找矿方法等多个方面对萤石矿床进行了系统阐述,并提出了存在的主要问题,以期为今后的萤石找矿工作有所帮助。