Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.Americ...Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.America’s“natural gas independence”has reshaped the global natural gas market,creating a new pattern of“supply shifting westward and consumption shifting eastward”.展开更多
In the context of China’s rapidly evolving capital market,the proliferation of listed companies has been a salient phenomenon.The quality of corporate governance has emerged as a pivotal factor in determining the suc...In the context of China’s rapidly evolving capital market,the proliferation of listed companies has been a salient phenomenon.The quality of corporate governance has emerged as a pivotal factor in determining the success or failure of these entities.Research by Balsmeier et al.(2022)indicates that the greater the independence of a listed company’s board of directors,the higher its innovation output(both in terms of quantity and quality of patents)^([1]).This finding suggests a strong correlation between the performance of a company and the independence of its board.The present study has selected listed companies on the A-share market of the Shanghai Stock Exchange in 2013 as the subjects of its research.A sample of 960 companies was initially obtained from the CSMAR database.Following a rigorous financial data screening,a final sample of 944 valid companies was retained for further analysis.展开更多
In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in ...In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in this paper,we prove that rooted products of some trees preserve real-rootedness of independence polynomials.In particular,we can obtain that their independence polynomials are unimodal and log-concave.展开更多
In this paper, the authors generalize the definition of χ 2 distribution and introduce a quasi χ 2 distribution, and then prove several properties of it, find the necessary and sufficient conditions of i...In this paper, the authors generalize the definition of χ 2 distribution and introduce a quasi χ 2 distribution, and then prove several properties of it, find the necessary and sufficient conditions of independence about multivariate normal distributions, matrix normal distributions and two parts of the Wishart distribution.展开更多
The relationship between wheat varieties and occurrence of head blight was discussed, the independence test was carried out by using contingency table.
文摘Since 2011,America has maintained its position as the world’s largest natural gas producer.Since 2017,America has consistently experienced a surplus in natural gas supply,becoming a net exporter of natural gas.America’s“natural gas independence”has reshaped the global natural gas market,creating a new pattern of“supply shifting westward and consumption shifting eastward”.
文摘In the context of China’s rapidly evolving capital market,the proliferation of listed companies has been a salient phenomenon.The quality of corporate governance has emerged as a pivotal factor in determining the success or failure of these entities.Research by Balsmeier et al.(2022)indicates that the greater the independence of a listed company’s board of directors,the higher its innovation output(both in terms of quantity and quality of patents)^([1]).This finding suggests a strong correlation between the performance of a company and the independence of its board.The present study has selected listed companies on the A-share market of the Shanghai Stock Exchange in 2013 as the subjects of its research.A sample of 960 companies was initially obtained from the CSMAR database.Following a rigorous financial data screening,a final sample of 944 valid companies was retained for further analysis.
基金supported by the National Natural Science Foundation of China(No.12271527)。
文摘In 1987,Alavi,Malde,Schwenk and Erdős conjectured that the independence polynomial of any tree or forest is unimodal.Although many researchers have been attracted by it,it is still open.Inspired by this conjecture,in this paper,we prove that rooted products of some trees preserve real-rootedness of independence polynomials.In particular,we can obtain that their independence polynomials are unimodal and log-concave.
文摘In this paper, the authors generalize the definition of χ 2 distribution and introduce a quasi χ 2 distribution, and then prove several properties of it, find the necessary and sufficient conditions of independence about multivariate normal distributions, matrix normal distributions and two parts of the Wishart distribution.
文摘The relationship between wheat varieties and occurrence of head blight was discussed, the independence test was carried out by using contingency table.
