Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this wo...Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated.展开更多
目的对比IOLMaster 700、OPD-ScanⅢ与MODi 2角膜地形图仪3种仪器在测量白内障患者水平角膜直径(white to white,WTW)、平坦轴角膜曲率(keratometry of flataxial,Kf)和陡峭轴角膜曲率(keratometry of steepaxial,Ks)的差异性和一致性...目的对比IOLMaster 700、OPD-ScanⅢ与MODi 2角膜地形图仪3种仪器在测量白内障患者水平角膜直径(white to white,WTW)、平坦轴角膜曲率(keratometry of flataxial,Kf)和陡峭轴角膜曲率(keratometry of steepaxial,Ks)的差异性和一致性。方法选取2019年11月至12月于西安市第四医院眼科白内障人工晶状体中心就诊并拟行白内障超声乳化抽吸联合人工晶状体植入术的患者54例(92只眼),其中男17例(28只眼),女37例(64只眼),平均年龄(52.83±15.00)岁。采用3种仪器分别测量患者的WTW、Kf、Ks。采用方差分析及LSD-t检验比较仪器间的差异性,Pearson相关性分析分析仪器相关性及Bland-Altman法评价仪器的一致性。结果 3种仪器测量WTW、Kf、Ks值时,只有IOLMaster 700与OPD-ScanⅢ的WTW值、OPD-ScanⅢ与MODi 2角膜地形图仪的WTW值差异有统计学意义(P<0.001),余测量值差异均无统计学意义(P>0.05)。相关性分析中,3种仪器测量值均呈现出显著正相关性,相关系数r在0.75~0.98之间。Bland Altman法评价仪器的一致性时,IOLMaster 700与OPD-ScanⅢ、IOLMaster 700与MODi 2角膜地形图仪、OPD-ScanⅢ与MODi 2角膜地形图仪测量WTW、Kf、Ks值95%一致性界限外比例分别为(5.43%、6.52%、4.34%)、(4.34%、4.34%和7.61%)、(5.43%、5.43%和7.61%)。结论 3种仪器测量Kf、Ks值差异无统计学意义,IOLMaster 700与MODi 2角膜地形图仪测量WTW值差异无统计学意义,但3种仪器测量Kf、Ks、WTW差异均有临床意义,不能互换使用。展开更多
基金Project(8212033)supported by the Natural Science Foundation of Beijing,ChinaProject(BBJ2023051)supported by the Fundamental Research Funds of China University of Mining and Technology-BeijingProject(SKLGDUEK202221)supported by the Innovation Fund Research Project,China。
文摘Every year in China,a significant number of mines are closed or abandoned.The pumped hydroelectric storage(PHS)and geothermal utilization are vital means to efficiently repurpose resources in abandoned mine.In this work,the development potentials of the PHS and geothermal utilization systems were evaluated.Considering the geological conditions and meteorological data available of Jiahe abandoned mine,a simple evaluation model for PHS and geothermal utilization was established.The average efficiency of the PHS system exceeds 70%and the regulatable energy of a unit volume is over 1.53 kW·h/m^(3).The PHS system achieves optimal performance when the wind/solar power ratio reaches 0.6 and 0.3 in daily and year scale,respectively.In the geothermal utilization system,the outlet temperature and heat production are significantly affected by the injection flow rate.The heat production performance is more stable at lower rate flow,and the proportion of heat production is higher in the initial stage at greater flow rate.As the operating time increases,the proportion of heat production gradually decreases.The cyclic heat storage status has obvious advantages in heat generation and cooling.Furthermore,the energy-saving and emission reduction benefits of PHS and geothermal utilization systems were calculated.
