[目的]研究关中地区土壤侵蚀时空分布特征,为制定精准有效的水土流失防治政策提供科学参考。[方法]基于中国土壤水土流失方程CSLE(Chinese soil loss equation)计算土壤侵蚀模数,采用ArcGIS的区域分析和叠加方法,分析关中地区土壤侵蚀...[目的]研究关中地区土壤侵蚀时空分布特征,为制定精准有效的水土流失防治政策提供科学参考。[方法]基于中国土壤水土流失方程CSLE(Chinese soil loss equation)计算土壤侵蚀模数,采用ArcGIS的区域分析和叠加方法,分析关中地区土壤侵蚀时空分布特征,土地利用类型、坡度及植被覆盖度对土壤侵蚀的影响。[结果]①2018—2022年,关中地区水土流失面积减少了568.67 km2,土壤侵蚀等级主要由中度及以上类型转移为微度和轻度。②关中地区土壤侵蚀呈现南北高中间低的分布特征。微度是关中地区主要的侵蚀类型;5 a间,微度及轻度侵蚀范围呈现从中间向两端扩大的趋势,强度及以上侵蚀范围则逐渐缩小。③8°~25°坡度带土壤侵蚀对坡度的敏感性较强;小于8°区域土壤侵蚀对坡度的敏感性较弱。④2018—2022年林地高覆盖度区域水土流失减少面积比例为72.60%,是引起水土流失面积减少的主要原因。⑤林地及耕地是研究区土壤侵蚀发生的主要土地利用类型。[结论]关中地区呈现水土流失面积减少和高等级侵蚀强度比例减少的双下降趋势,土壤侵蚀状况好转。8°~25°坡度带是进行坡耕地治理时需要重点关注的区域;高覆盖林地对于减少水土流失面积至关重要。展开更多
Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)an...Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.展开更多
文摘Hydroxyapatite nanoparticles(HAP NPs)were synthesized by a one‐step hydrothermal method.The surface of HAP NPs was grafted-SH and-COOH chelating groups via in situ surface‐modification with iminodiacetic acid(IDA)and 3‐mercaptopropyl trimethoxysilane(MPS)to afford dual surface‐capped nano‐amendment HAPIDA/MPS.The structure of HAP‐IDA/MPS was characterized,and its adsorption performance for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)was evaluated.The total adsorption capacity of 0.10 g HAP‐IDA/MPS nano‐amendment for Hg^(2+),Cu^(2+),Zn^(2+),Ni^(2+),Co^(2+),and Cd^(2+)with an initial mass concentration of 20 mg·L^(-1) reached 13.7 mg·g^(-1),about 4.3 times as much as that of HAP.Notably,HAP‐IDA/MPS nano‐amendment displayed the highest immobilization rate for Hg^(2+),possibly because of its chemical reaction with-SH to form sulfide,possessing the lowest solubility product constant among a variety of metal sulfides.
