Mei symmetry and Mei conserved quantity for a non-holonomic system of non-Chetaev's type with unilateralconstraints in the Nielsen style are studied.The differential equations of motion for the system above are es...Mei symmetry and Mei conserved quantity for a non-holonomic system of non-Chetaev's type with unilateralconstraints in the Nielsen style are studied.The differential equations of motion for the system above are established.The definition and the criteria of Mei symmetry,conditions,and expressions of Mei conserved quantity deduced directlyfrom the Mei symmetry are given.An example is given to illustrate the application of the results.展开更多
We provide evidence on the effect of the presentation format and information content of Internet financial reporting on the market value of American Depository Receipts and on country-specific variables that drive Int...We provide evidence on the effect of the presentation format and information content of Internet financial reporting on the market value of American Depository Receipts and on country-specific variables that drive Internet financial reporting. A two-stage Heckman approach was used to determine if Internet financial reporting adds incremental value to firms beyond the decision to cross-list in the United States. The results indicate that investors more highly value firms that provide information in multiple formats. We also find that country-specific variables affect the information content, but not the presentation format of disclosures on corporate websites. The results uncover a disconnection between what the market values （presentation format） and what the firms believe the market values （information content）. This implies that firms are not entirely aware of investors＇ information wants and that they are not utilizing their resources in the manner that will have the most impact on their market value.展开更多
In recent years, peculiar physical phenomena enabled by non-Hermitian systems, especially the parity-time(PT)-symmetric systems, have drawn tremendous research interests. Particularly, special spectral degeneracies kn...In recent years, peculiar physical phenomena enabled by non-Hermitian systems, especially the parity-time(PT)-symmetric systems, have drawn tremendous research interests. Particularly, special spectral degeneracies known as exceptional points(EPs) and coherent perfect absorber-laser(CPAL) points where zero and infinite large eigenvalues coexist are the most popular topics to be studied. To date, the discussions of EPs that serve as transition boundaries between broken PT-symmetry phase and exact PT-symmetry phase have been intensively presented. However, the theoretical analysis and experimental validations of CPAL points are inadequate. Different from EPs, CPAL points, as a special solution of broken PT-symmetry phase, may exhibit even further counterintuitive physical features, which may have significant implications to study non-Hermitian physics. Here, we review some recent advances of CPAL phenomena in different sub-disciplines of physics, including optics, electronics and electromagnetics, and acoustics.Additionally, we also provide an envision of future directions and applications of CPAL systems.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.10572021Preparatory Research Foundation of Jiangnan under Grant No.2008LYY011
文摘Mei symmetry and Mei conserved quantity for a non-holonomic system of non-Chetaev's type with unilateralconstraints in the Nielsen style are studied.The differential equations of motion for the system above are established.The definition and the criteria of Mei symmetry,conditions,and expressions of Mei conserved quantity deduced directlyfrom the Mei symmetry are given.An example is given to illustrate the application of the results.
文摘We provide evidence on the effect of the presentation format and information content of Internet financial reporting on the market value of American Depository Receipts and on country-specific variables that drive Internet financial reporting. A two-stage Heckman approach was used to determine if Internet financial reporting adds incremental value to firms beyond the decision to cross-list in the United States. The results indicate that investors more highly value firms that provide information in multiple formats. We also find that country-specific variables affect the information content, but not the presentation format of disclosures on corporate websites. The results uncover a disconnection between what the market values （presentation format） and what the firms believe the market values （information content）. This implies that firms are not entirely aware of investors＇ information wants and that they are not utilizing their resources in the manner that will have the most impact on their market value.
文摘In recent years, peculiar physical phenomena enabled by non-Hermitian systems, especially the parity-time(PT)-symmetric systems, have drawn tremendous research interests. Particularly, special spectral degeneracies known as exceptional points(EPs) and coherent perfect absorber-laser(CPAL) points where zero and infinite large eigenvalues coexist are the most popular topics to be studied. To date, the discussions of EPs that serve as transition boundaries between broken PT-symmetry phase and exact PT-symmetry phase have been intensively presented. However, the theoretical analysis and experimental validations of CPAL points are inadequate. Different from EPs, CPAL points, as a special solution of broken PT-symmetry phase, may exhibit even further counterintuitive physical features, which may have significant implications to study non-Hermitian physics. Here, we review some recent advances of CPAL phenomena in different sub-disciplines of physics, including optics, electronics and electromagnetics, and acoustics.Additionally, we also provide an envision of future directions and applications of CPAL systems.
