本文通过《丙子日记》(Beongjaiki)探究了17世纪前半期的气候危机和农业生产状况。南平曹氏的《丙子日记》具有气候史及农业史方面的意义。《丙子日记》的记录的气候变化和《朝鲜王朝实录》及树轮研究(Tree Ring Research)结果完全一致...本文通过《丙子日记》(Beongjaiki)探究了17世纪前半期的气候危机和农业生产状况。南平曹氏的《丙子日记》具有气候史及农业史方面的意义。《丙子日记》的记录的气候变化和《朝鲜王朝实录》及树轮研究(Tree Ring Research)结果完全一致。从《丙子日记》中可知土地的耕作体系中已经出现了水田种麦法,但移秧法还没有普及,水田直播法是普遍采用的方法。《丙子日记》还集中体现了奴婢生产关系,奴婢们跟随南平曹氏参与了农业赋役劳动,主仆之间的关系甚至发展到相互依赖程度。展开更多
We report a facile coagglomeration method for preparing graphene (G)/MgCl2‐supported Ti‐based Ziegler‐Natta catalysts. The effects of graphene feed ratio on catalyst morphology and ethylene polymerization behavior ...We report a facile coagglomeration method for preparing graphene (G)/MgCl2‐supported Ti‐based Ziegler‐Natta catalysts. The effects of graphene feed ratio on catalyst morphology and ethylene polymerization behavior were examined. The synthesized catalyst exhibited very high activity for ethylene polymerization. The resultant polyethylene (PE)/G nanocomposites showed a layered morphology, and the graphene fillers were well dispersed in the PE matrix. In addition, the thermal stability and mechanical properties of PE were significantly enhanced with the introduction of a very small amount of G fillers (0.05 wt%). This work provides a facile approach to the production o fhigh‐performance PE.展开更多
文摘本文通过《丙子日记》(Beongjaiki)探究了17世纪前半期的气候危机和农业生产状况。南平曹氏的《丙子日记》具有气候史及农业史方面的意义。《丙子日记》的记录的气候变化和《朝鲜王朝实录》及树轮研究(Tree Ring Research)结果完全一致。从《丙子日记》中可知土地的耕作体系中已经出现了水田种麦法,但移秧法还没有普及,水田直播法是普遍采用的方法。《丙子日记》还集中体现了奴婢生产关系,奴婢们跟随南平曹氏参与了农业赋役劳动,主仆之间的关系甚至发展到相互依赖程度。
基金supported by the National Research Foundation of Korea (NRF-2015R1D1A1A0161012)the National Natural Science Foundation of China (U1462124)~~
文摘We report a facile coagglomeration method for preparing graphene (G)/MgCl2‐supported Ti‐based Ziegler‐Natta catalysts. The effects of graphene feed ratio on catalyst morphology and ethylene polymerization behavior were examined. The synthesized catalyst exhibited very high activity for ethylene polymerization. The resultant polyethylene (PE)/G nanocomposites showed a layered morphology, and the graphene fillers were well dispersed in the PE matrix. In addition, the thermal stability and mechanical properties of PE were significantly enhanced with the introduction of a very small amount of G fillers (0.05 wt%). This work provides a facile approach to the production o fhigh‐performance PE.