Quantum degenerate code may improve the hashing bound of quantum capacity. We propose a family of quantum degenerate codes derived from two-colorable graphs. The coherent information of the codes is analyticaJly obtai...Quantum degenerate code may improve the hashing bound of quantum capacity. We propose a family of quantum degenerate codes derived from two-colorable graphs. The coherent information of the codes is analyticaJly obtained as a function of the channd noise for the depolarizing channel. We find a new code which has a higher noise threshold than that of the repetition code.展开更多
Sustained large-scale migration has been an important structural force bringing about change in the Chinese peasant family. The de-localization resulting from population movement has eroded and undermined the patriarc...Sustained large-scale migration has been an important structural force bringing about change in the Chinese peasant family. The de-localization resulting from population movement has eroded and undermined the patriarchal family system, with its high degree of overlap between kin-based and place-based ties. The resultant changes in the family institution, however, represent not just a de-traditionalization, but also at the same time a process of reconstructing tradition. The continuation and reconstruction of the patriarchal family in the midst of deconstruction is a result of the interplay of institutional constraints, market dominance and the patrilineal and patriarchal system＇s own need for continued authority. This changing family pattern not only provides a low-cost basis for the survival and development of migrant workers ＂working in the city but rooted in the countryside,＂ but also, through its peculiarly flexible adaptability, serves as a buffer for dealing with contradictions and conflicts arising from changes in rural society and plays a role in relieving social tensions under specific historical conditions.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.60972071 and 11375152
文摘Quantum degenerate code may improve the hashing bound of quantum capacity. We propose a family of quantum degenerate codes derived from two-colorable graphs. The coherent information of the codes is analyticaJly obtained as a function of the channd noise for the depolarizing channel. We find a new code which has a higher noise threshold than that of the repetition code.
文摘Sustained large-scale migration has been an important structural force bringing about change in the Chinese peasant family. The de-localization resulting from population movement has eroded and undermined the patriarchal family system, with its high degree of overlap between kin-based and place-based ties. The resultant changes in the family institution, however, represent not just a de-traditionalization, but also at the same time a process of reconstructing tradition. The continuation and reconstruction of the patriarchal family in the midst of deconstruction is a result of the interplay of institutional constraints, market dominance and the patrilineal and patriarchal system＇s own need for continued authority. This changing family pattern not only provides a low-cost basis for the survival and development of migrant workers ＂working in the city but rooted in the countryside,＂ but also, through its peculiarly flexible adaptability, serves as a buffer for dealing with contradictions and conflicts arising from changes in rural society and plays a role in relieving social tensions under specific historical conditions.
