随着城市化进程的加快,城市用地逐渐硬质化,这是城市暴雨内涝发生的重要原因。城市绿地作为软质下垫面,对雨水径流有显著的渗透、滞留及调蓄作用。该文借助CNKI数据库和Web of Science数据库,利用文献计量学方法,对国内外关于绿地雨洪...随着城市化进程的加快,城市用地逐渐硬质化,这是城市暴雨内涝发生的重要原因。城市绿地作为软质下垫面,对雨水径流有显著的渗透、滞留及调蓄作用。该文借助CNKI数据库和Web of Science数据库,利用文献计量学方法,对国内外关于绿地雨洪调蓄能力方面的文献进行统计分析,从宏观、中观、微观三个方面综述了绿地雨洪调蓄能力的研究热点和研究方向,总结了目前研究存在的不足并提出展望,希望为最大化城市绿地雨洪调蓄能力的研究提供参考。展开更多
Spinel lithium manganese oxide cathode materials were synthesized using the ultrasonic-assisted sol-gel method. The synthesized samples were investigated by differential thermal analysis （DTA） and thermogravimetry ...Spinel lithium manganese oxide cathode materials were synthesized using the ultrasonic-assisted sol-gel method. The synthesized samples were investigated by differential thermal analysis （DTA） and thermogravimetry （TG）, powder X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, and the charge-discharge test. TG-DTA shows that significant mass loss occurs in two temperature regions during the synthesis of LiLa0.01Mn1.9903.99F0.01. XRD data indicate that all samples exhibit the same pure spinel phase, and LiLa0.01Mn1.9903.99F0.01 and LiLa0.01Mn1.9904 samples have a better crystallinity than LiMn2O4. SEM images indicate that LiLa0.01Mn1.9903.99F0.01 has a slightly smaller particle size and a more regular morphology structure with narrow size distribution. The charge-discharge test reveals that the initial capacities of LiMn2O4, LiLa0.01Mn1.99O4, and LiLa0.01Mn1.99O3.99F0.01 are 130, 123, and 126 mAh·g^-1, respectively, and the capacity retention rates of the initial value, after 50 cycles, are 84.8%, 92.3%, and 92.1%, respectively. The electrode coulomb efficiency and CV reveal that the electrode synthesized by the ultrasonic-assisted sol-gel （UASG） method has a better re- versibility than the electrode synthesized by the sol-gel method.展开更多
文摘随着城市化进程的加快,城市用地逐渐硬质化,这是城市暴雨内涝发生的重要原因。城市绿地作为软质下垫面,对雨水径流有显著的渗透、滞留及调蓄作用。该文借助CNKI数据库和Web of Science数据库,利用文献计量学方法,对国内外关于绿地雨洪调蓄能力方面的文献进行统计分析,从宏观、中观、微观三个方面综述了绿地雨洪调蓄能力的研究热点和研究方向,总结了目前研究存在的不足并提出展望,希望为最大化城市绿地雨洪调蓄能力的研究提供参考。
文摘Spinel lithium manganese oxide cathode materials were synthesized using the ultrasonic-assisted sol-gel method. The synthesized samples were investigated by differential thermal analysis （DTA） and thermogravimetry （TG）, powder X-ray diffraction （XRD）, scanning electron microscopy （SEM）, cyclic voltammetry （CV）, and the charge-discharge test. TG-DTA shows that significant mass loss occurs in two temperature regions during the synthesis of LiLa0.01Mn1.9903.99F0.01. XRD data indicate that all samples exhibit the same pure spinel phase, and LiLa0.01Mn1.9903.99F0.01 and LiLa0.01Mn1.9904 samples have a better crystallinity than LiMn2O4. SEM images indicate that LiLa0.01Mn1.9903.99F0.01 has a slightly smaller particle size and a more regular morphology structure with narrow size distribution. The charge-discharge test reveals that the initial capacities of LiMn2O4, LiLa0.01Mn1.99O4, and LiLa0.01Mn1.99O3.99F0.01 are 130, 123, and 126 mAh·g^-1, respectively, and the capacity retention rates of the initial value, after 50 cycles, are 84.8%, 92.3%, and 92.1%, respectively. The electrode coulomb efficiency and CV reveal that the electrode synthesized by the ultrasonic-assisted sol-gel （UASG） method has a better re- versibility than the electrode synthesized by the sol-gel method.
