Background:Research in various academic disciplines has undergone tremendous changes in the era of big data.Everyone is talking about big data nowadays,but how exactly is it being applied in research on financial stud...Background:Research in various academic disciplines has undergone tremendous changes in the era of big data.Everyone is talking about big data nowadays,but how exactly is it being applied in research on financial studies?Results:This study summarizes the sources of Internet big data for research related to capital markets and the analytical methods that have been used in the literature.In addition,it presents a review of the research findings based on Internet big data in the field of capital markets and proposes suggestions for future studies in which big data can be applied to examine issues related to capital markets.Conclusion:(1)Internet big data sources related to present capital market research can be categorized into forum-type data,microblog-type data and search class data.(2)As for research about investors’sentiments on the basis of Internet big data,the main methods of sentiment analysis include building an inventory of lexical categories,using dictionaries for analysis of lexical categories,and machine learning.(3)Many studies address whether Internet big data can predict capital markets.However,they reach no consistent conclusions,which could be due to limitations of sample and analysis method used.(4)Data collection technique and analysis methods require further improvements.展开更多
The order–disorder transition(ODT)of A_(2)B_(2)O_(7)compounds obtained enormous attention owing to the potential application for thermal barrier coating(TBC)design.In this work,the influence of ODT on the mechanical ...The order–disorder transition(ODT)of A_(2)B_(2)O_(7)compounds obtained enormous attention owing to the potential application for thermal barrier coating(TBC)design.In this work,the influence of ODT on the mechanical and thermophysical properties of dual-phase A_(2)B_(2)O_(7)high-entropy ceramics was investigated by substituting Ce^(4+)and Hf^(4+)with different ionic radii on B-sites(Zr^(4+)).The X-ray diffraction(XRD),Raman,and transmission electron microscopy(TEM)results show that rA3+/rB^(4+)=1.47 is the critical value of ODT phase boundary with different doping B-site ion contents,and the energy dispersive spectroscopy(EDS)results further indicate the uniform distribution of elements.Interestingly,owing to the high intrinsic disorder derived from high-entropy effect,the A_(2)B_(2)O_(7)high-entropy ceramics exhibit unreduced modulus(E0≈230 GPa)and enhanced mechanical properties(HV≈10 GPa,KIC≈2.3 MPa·m^(0.5)).A_(2)B_(2)O_(7)high-entropy ceramics exhibit excellent thermal stability with relatively high thermal expansion coefficients(TECs)(Hf_(0.25),11.20×10-6 K-1,1000℃).Moreover,the matching calculation implied that the ODT further enhances the phonon scattering coefficient,leading to a relatively lower thermal conductivity of(La_(0.25)Eu_(0.25)Gd_(0.25)Yb_(0.25))2(Zr_(0.85)Ce_(0.15))_(2)O_(7)(1.48–1.51 W/(m·K),100–500℃)compared with other components.This present work provides a novel composition design principle for high-entropy ceramics,as well as a material selection rule for high-temperature insulation applications.展开更多
This paper examines how independent directors’social capital,as measured by their social network,affects corporate fraud.We find that firms with wellconnected independent directors are less likely to commit fraud,sup...This paper examines how independent directors’social capital,as measured by their social network,affects corporate fraud.We find that firms with wellconnected independent directors are less likely to commit fraud,supporting our monitoring effect hypothesis.This result is robust to a battery of tests.Further analyses show that the effect is stronger for firms with a relatively poor legal environment,for firms whose independent directors face strong reputation incentives and when independent directors are audit committee members.Moreover,we explore a potential economic mechanism of the effect and observe that well-connected independent directors are associated with less absenteeism and more dissension.Overall,our findings suggest that independent directors’social capital plays an important role in corporate governance.展开更多
基金National Nature Sciences Foundation of China(No.71372148).
文摘Background:Research in various academic disciplines has undergone tremendous changes in the era of big data.Everyone is talking about big data nowadays,but how exactly is it being applied in research on financial studies?Results:This study summarizes the sources of Internet big data for research related to capital markets and the analytical methods that have been used in the literature.In addition,it presents a review of the research findings based on Internet big data in the field of capital markets and proposes suggestions for future studies in which big data can be applied to examine issues related to capital markets.Conclusion:(1)Internet big data sources related to present capital market research can be categorized into forum-type data,microblog-type data and search class data.(2)As for research about investors’sentiments on the basis of Internet big data,the main methods of sentiment analysis include building an inventory of lexical categories,using dictionaries for analysis of lexical categories,and machine learning.(3)Many studies address whether Internet big data can predict capital markets.However,they reach no consistent conclusions,which could be due to limitations of sample and analysis method used.(4)Data collection technique and analysis methods require further improvements.
基金This work was supported by the National Natural Science Foundation of China(No.52072301)State Key Laboratory of New Ceramics and Fine Processing Tsinghua University(No.KFZD202102)+3 种基金State Key Laboratory of Solidification Processing(NPU)(No.2021-TS-08)the China–Poland International Collaboration Fund of the National Natural Science Foundation of China(No.51961135301)the Fundamental Research Funds for the Central Universities(No.D5000210722)State Key Laboratory of Materials Processing and Die&Mould Technology,Huazhong University of Science and Technology(No.P2020-009)。
文摘The order–disorder transition(ODT)of A_(2)B_(2)O_(7)compounds obtained enormous attention owing to the potential application for thermal barrier coating(TBC)design.In this work,the influence of ODT on the mechanical and thermophysical properties of dual-phase A_(2)B_(2)O_(7)high-entropy ceramics was investigated by substituting Ce^(4+)and Hf^(4+)with different ionic radii on B-sites(Zr^(4+)).The X-ray diffraction(XRD),Raman,and transmission electron microscopy(TEM)results show that rA3+/rB^(4+)=1.47 is the critical value of ODT phase boundary with different doping B-site ion contents,and the energy dispersive spectroscopy(EDS)results further indicate the uniform distribution of elements.Interestingly,owing to the high intrinsic disorder derived from high-entropy effect,the A_(2)B_(2)O_(7)high-entropy ceramics exhibit unreduced modulus(E0≈230 GPa)and enhanced mechanical properties(HV≈10 GPa,KIC≈2.3 MPa·m^(0.5)).A_(2)B_(2)O_(7)high-entropy ceramics exhibit excellent thermal stability with relatively high thermal expansion coefficients(TECs)(Hf_(0.25),11.20×10-6 K-1,1000℃).Moreover,the matching calculation implied that the ODT further enhances the phonon scattering coefficient,leading to a relatively lower thermal conductivity of(La_(0.25)Eu_(0.25)Gd_(0.25)Yb_(0.25))2(Zr_(0.85)Ce_(0.15))_(2)O_(7)(1.48–1.51 W/(m·K),100–500℃)compared with other components.This present work provides a novel composition design principle for high-entropy ceramics,as well as a material selection rule for high-temperature insulation applications.
文摘This paper examines how independent directors’social capital,as measured by their social network,affects corporate fraud.We find that firms with wellconnected independent directors are less likely to commit fraud,supporting our monitoring effect hypothesis.This result is robust to a battery of tests.Further analyses show that the effect is stronger for firms with a relatively poor legal environment,for firms whose independent directors face strong reputation incentives and when independent directors are audit committee members.Moreover,we explore a potential economic mechanism of the effect and observe that well-connected independent directors are associated with less absenteeism and more dissension.Overall,our findings suggest that independent directors’social capital plays an important role in corporate governance.
