By analyses on the trace elements of coals,host-rocks and wall-rocks,this study aims to trace the sources and evaluate the utilization prospects of REE+Y(REY)in coals from Bayili Coal Mine(Wensu,Xinjiang,China).The di...By analyses on the trace elements of coals,host-rocks and wall-rocks,this study aims to trace the sources and evaluate the utilization prospects of REE+Y(REY)in coals from Bayili Coal Mine(Wensu,Xinjiang,China).The distribution patterns of REY in the coals are divided into two groups,flat-type and heavy REE-enrichment type(H-type).The REY of the former was mainly from the gneisses of the basement of the coal-bearing basin,and that of the later was partly from hydrothermal solution.The host-rocks show two types of REY patterns,middle REE-enrichment type(M-type)and H-type,which are due to the injection of REY from acid terrestrial water and hydrothermal solution,respectively.Almost all the coal samples are plotted into the promising area on the diagram of percentage of critical elements(REY_(def,rel))vs ratio of sum of critical elements to the sum of excessive elements(C_(outl))and half of the coal samples have high contents of Ga closing to the cut-off grade of Ga deposit as by-product,which indicate that the REY and Ga in Bayili Coal Mine are of utilization prospects as by-product.展开更多
[目的]分析干旱区受损植被恢复过程中生态需水量,为生态恢复不同阶段所需水资源量及水资源优化配置提供科学依据。[方法]基于1990,2000,2010,2015,2020年Landsat系列影像,采用遥感技术,结合改进的彭曼公式法,对新疆哈巴河县平原区植被...[目的]分析干旱区受损植被恢复过程中生态需水量,为生态恢复不同阶段所需水资源量及水资源优化配置提供科学依据。[方法]基于1990,2000,2010,2015,2020年Landsat系列影像,采用遥感技术,结合改进的彭曼公式法,对新疆哈巴河县平原区植被耗水量时空演变特征及生态恢复需水量进行了定量研究。[结果]①1990—2020年天然植被平均耗水量为7.55×10^(8)m^(3),以3.60×10^(7)m^(3)/5 a的速率减小,与之对应的是天然植被面积以17.36 km 2/a的速率减小,植被覆盖度从高植被覆盖度向中植被覆盖度转化,生态受损严重。②区域内植被耗水量时空分布均存在较大差异:空间上高值主要分布于哈巴河流域,别列则克河流域植被耗水量整体偏低;时间上年际变化以2000年植被耗水量为最高,年内植被耗水量则主要集中在生长中期。③绿洲区生态恢复需水量如下:维持现状(2020年)生态需水量为4.62×10^(8)m^(3),恢复到1990—2020年生态平均水平生态需水量为6.65×10^(8)m^(3),达到1990—2020年生态最佳水平(2000年)生态需水量为9.55×10^(8)m^(3)。[结论]在人为与自然二元作用下,灌区1990—2020年生态环境整体呈现退化趋势,生态耗水空间分配失衡,受损植被生态恢复需水量时空配置应根据耗水时空分布进行优化完善。展开更多
基金the National Natural Science Foundation of China(Nos.42004107,42074165)the Open Research Fund Program of Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University)+1 种基金Ministry of Education,China(No.2019YSJS13)Department of Water Resources of Hunan Province,China(No.XSKJ2019081).
文摘By analyses on the trace elements of coals,host-rocks and wall-rocks,this study aims to trace the sources and evaluate the utilization prospects of REE+Y(REY)in coals from Bayili Coal Mine(Wensu,Xinjiang,China).The distribution patterns of REY in the coals are divided into two groups,flat-type and heavy REE-enrichment type(H-type).The REY of the former was mainly from the gneisses of the basement of the coal-bearing basin,and that of the later was partly from hydrothermal solution.The host-rocks show two types of REY patterns,middle REE-enrichment type(M-type)and H-type,which are due to the injection of REY from acid terrestrial water and hydrothermal solution,respectively.Almost all the coal samples are plotted into the promising area on the diagram of percentage of critical elements(REY_(def,rel))vs ratio of sum of critical elements to the sum of excessive elements(C_(outl))and half of the coal samples have high contents of Ga closing to the cut-off grade of Ga deposit as by-product,which indicate that the REY and Ga in Bayili Coal Mine are of utilization prospects as by-product.
文摘[目的]分析干旱区受损植被恢复过程中生态需水量,为生态恢复不同阶段所需水资源量及水资源优化配置提供科学依据。[方法]基于1990,2000,2010,2015,2020年Landsat系列影像,采用遥感技术,结合改进的彭曼公式法,对新疆哈巴河县平原区植被耗水量时空演变特征及生态恢复需水量进行了定量研究。[结果]①1990—2020年天然植被平均耗水量为7.55×10^(8)m^(3),以3.60×10^(7)m^(3)/5 a的速率减小,与之对应的是天然植被面积以17.36 km 2/a的速率减小,植被覆盖度从高植被覆盖度向中植被覆盖度转化,生态受损严重。②区域内植被耗水量时空分布均存在较大差异:空间上高值主要分布于哈巴河流域,别列则克河流域植被耗水量整体偏低;时间上年际变化以2000年植被耗水量为最高,年内植被耗水量则主要集中在生长中期。③绿洲区生态恢复需水量如下:维持现状(2020年)生态需水量为4.62×10^(8)m^(3),恢复到1990—2020年生态平均水平生态需水量为6.65×10^(8)m^(3),达到1990—2020年生态最佳水平(2000年)生态需水量为9.55×10^(8)m^(3)。[结论]在人为与自然二元作用下,灌区1990—2020年生态环境整体呈现退化趋势,生态耗水空间分配失衡,受损植被生态恢复需水量时空配置应根据耗水时空分布进行优化完善。
