排序方式: 共有6条查询结果,搜索用时 160 毫秒
1
1.
2.
基于2005―2019年中国10个主要港口城市的面板数据, 通过耦合协同度模型测算港城耦合协同水平, 使用双向固定效应模型检验港城协同对城市经济增长的影响. 结果表明: (1)我国主要港口城市的港城耦合协同度在2005―2019年期间整体呈现上升趋势, 其中上海的港城耦合协同水平最高. (2)我国主要港口城市间的港口与城市发展水平存在差距, 港城协同发展水平仍存在较大的提升空间. (3)港城协同发展能够显著促进城市经济增长, 此结论在IV-GMM、IV-LIML等多种估计方法下依旧稳健. 相似文献
3.
4.
5.
A new method was proposed to prepare binary composite colloidal crystal hydrogels by interlocking the as-prepared polystyrene/sulfonated polystyrene core/shell colloidal crystal hydrogel with a second responsive gel. The shell thickness thus the core size were synchronously controlled by altering the sulfonation time and temperature. The proper monomers were radically polymerized forming the second gel within the first gel network. The composition and structure were confirmed. Nanopatterued hydrogel including porous bulk hydrogels and surface patterned hydrogels were derived by properly treating the binary composite hydrogels. Specially, some typical patterns such as arrays of “nano-bowls” ,arrays of “nano-ribbons” and “nano-mask” were achieved by changing the treatment method such as by immersion in the solvent, after solvent evaporation from the sample surface during high rate rotation. This work provides a method to prepare nanopatterued hydrogels. 相似文献
6.
氢键诱导聚马来酸单酸液晶复合物的合成及表征 总被引:2,自引:1,他引:2
合成了聚马来酸6-(4-辛氧基偶氮苯氧基)在-己酯,并以其为质子给体,4-(4-庚氧基苯甲酰氧基)-苯乙烯基吡啶为质子受体,研究了两者复合前后的液晶行为。 相似文献
1