本文应用基于松弛的全局ML指数(slacks based measure of global Malmquist-Luenberger index,SBM-GML)法来测算我国中部区域2008—2019年期间的绿色生产率(green total factor productivity,GTFP),采用空间引力模型衡量中部地区旅游业...本文应用基于松弛的全局ML指数(slacks based measure of global Malmquist-Luenberger index,SBM-GML)法来测算我国中部区域2008—2019年期间的绿色生产率(green total factor productivity,GTFP),采用空间引力模型衡量中部地区旅游业绿色生产率空间联系强度,并对其驱动因素进行考察研究。研究发现:2008—2019年中部地区旅游业绿色生产率波动幅度较大,整体呈现出上升的趋势;各省的旅游业绿色生产率差异不大,山西省的旅游业绿色生产率位于中部六省之首;中部六省的旅游业绿色生产率间空间联结格局变化较为稳定,相邻省市间旅游业绿色生产率空间联系强度较高;区位熵、交通便利程度、GDP(国内生产总值)、对中部地区旅游业绿色生产率产生正向的影响。展开更多
The microstructure and properties of a quarternary Mg-8Er-5Zn-0.5Zr(mass fraction, %) alloy with the low Er/Zn mass ratio of 1.60 were investigated. It is found that despite of the low Er/Zn mass ratio, the microstruc...The microstructure and properties of a quarternary Mg-8Er-5Zn-0.5Zr(mass fraction, %) alloy with the low Er/Zn mass ratio of 1.60 were investigated. It is found that despite of the low Er/Zn mass ratio, the microstructure of the as-prepared alloy is composed of α-Mg, W phase with face-centered cubic structure and long packed stacking ordered(LPSO) phase. As expected, the extruded and annealed alloy possesses high yield stress(310 MPa) and good elongation(14%) at room temperature. The superior mechanical properties can be interpreted in terms of the promising microstructure characteristic of fine α-Mg recrystallized grains embedded with high-density fine lamellar-shaped LPSO phase and block W phase structure.展开更多
文摘本文应用基于松弛的全局ML指数(slacks based measure of global Malmquist-Luenberger index,SBM-GML)法来测算我国中部区域2008—2019年期间的绿色生产率(green total factor productivity,GTFP),采用空间引力模型衡量中部地区旅游业绿色生产率空间联系强度,并对其驱动因素进行考察研究。研究发现:2008—2019年中部地区旅游业绿色生产率波动幅度较大,整体呈现出上升的趋势;各省的旅游业绿色生产率差异不大,山西省的旅游业绿色生产率位于中部六省之首;中部六省的旅游业绿色生产率间空间联结格局变化较为稳定,相邻省市间旅游业绿色生产率空间联系强度较高;区位熵、交通便利程度、GDP(国内生产总值)、对中部地区旅游业绿色生产率产生正向的影响。
基金Project(51171120)supported by the National Natural Science Foundation of China
文摘The microstructure and properties of a quarternary Mg-8Er-5Zn-0.5Zr(mass fraction, %) alloy with the low Er/Zn mass ratio of 1.60 were investigated. It is found that despite of the low Er/Zn mass ratio, the microstructure of the as-prepared alloy is composed of α-Mg, W phase with face-centered cubic structure and long packed stacking ordered(LPSO) phase. As expected, the extruded and annealed alloy possesses high yield stress(310 MPa) and good elongation(14%) at room temperature. The superior mechanical properties can be interpreted in terms of the promising microstructure characteristic of fine α-Mg recrystallized grains embedded with high-density fine lamellar-shaped LPSO phase and block W phase structure.