农业生产营养物质的输出是造成水环境污染的重要原因之一。该文以北京密云水库周边地区为研究区域,基于土地利用、土壤以及降水等下垫面信息,利用长期水文影响评价(T he Long-T erm Hydro log ic Im pact A ssessm en t,L-TH IA)模型,...农业生产营养物质的输出是造成水环境污染的重要原因之一。该文以北京密云水库周边地区为研究区域,基于土地利用、土壤以及降水等下垫面信息,利用长期水文影响评价(T he Long-T erm Hydro log ic Im pact A ssessm en t,L-TH IA)模型,估算研究区内污染物的长期平均输出负荷,并分析其空间分布特征。研究结果表明:不同土地利用类型的污染物输出负荷是不同的,其中以农用地对研究区内非点源污染的影响最大。结果表明,在流域规划和管理中使用L-TH IA模型分析农业非点源污染的空间分布是可行的。展开更多
以大亚湾为研究对象,采用3S(GIS、RS和GPS)技术划分了汇水区范围并处理获得土地利用、土壤水文单元及降水等下垫面信息,运用L-THIA模型(Long-term Hydrologic Impact and Non Point Source Pollutant Model)构建了总氮(TN)这一指标的大...以大亚湾为研究对象,采用3S(GIS、RS和GPS)技术划分了汇水区范围并处理获得土地利用、土壤水文单元及降水等下垫面信息,运用L-THIA模型(Long-term Hydrologic Impact and Non Point Source Pollutant Model)构建了总氮(TN)这一指标的大亚湾汇水区非点源污染模型,并通过径流量与负荷量模拟结果与不同方法计算结果的比对验证了模型的合理性。结果表明,大亚湾陆域非点源TN年均负荷量为2 559 t;土地利用类型中耕地、建设用地和园地的负荷量和单位面积流失强度均较高,是TN流失的主要土地利用类型;汇水区涉及的11个镇(街)中惠州市稔山镇、平海镇对TN负荷量的贡献合计超过50. 0%,占据了77. 7%的TN流失关键源区,是非点源污染防治需重点关注的区域。来源贡献的定量识别和关键源区的空间识别为大亚湾陆域非点源TN污染的有效控制提供了重要的科学依据。展开更多
Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bro...Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bromoethoxy and 1,11-dioxa-4,8-dithiahendecene were successfully synthesized,with their extraction effectiveness towards Hg^(2+)and Pb^(2+)were evaluated respectively.The results indicated that the phenolic hydroxyl in calix[4]arene improved the extraction ability on Hg^(2+)by promoting the formation of the negative oxygen ions that could bind with Hg^(2+)by coordination and ionic bonds.The extraction ability of 5,17-dinitro-26,28-(1’,11’-dioxa-4’,8’-dithiahendecene)-calix[4]arene(calix[4]arene thia derivative)was improved slightly due to the better coordination capacity for metal ions after introduction of 1,11-dioxa-4,8-dithiahendecene,which was a chelate-binding centre.Regarding to Pb^(2+),only 1,11-dioxa-4,8-dithiahendecene on molecule contributed to extraction due to the coordination bond.Since the metal ion with higher charge-to-radius ratio could coordinate with one ligand more stably,Pb^(2+)with higher charge-to-radius ratio than Hg^(2+)was coordinated and extracted by the calix[4]arene thia derivative more easily.Furthermore,extraction rates of the calix[4]arene thia derivative on both ions(Hg^(2+)and Pb^(2+))increased with the increase of pH value in acidic aqueous system(pH<7).展开更多
A new type of ferrocenyl thia crown ethers used as selective ligands to some poisonous metals was synthesized, and the features of their mass spectra in electron ionization mode were summarized as: (1) the strong mol...A new type of ferrocenyl thia crown ethers used as selective ligands to some poisonous metals was synthesized, and the features of their mass spectra in electron ionization mode were summarized as: (1) the strong molecular ion peaks; (2) a characteristic homologous ion series with sequential loss of C 2H 4S or C 2H 4O from M C 5H 5; (3) a new rearrangement reaction of Fe migration; (4) the uncommon loss of alcohol or thiol from the fragments of Fe rearrangement. Some typical fragmentation patterns were discussed in detail with the aid of exact mass measurement and MS/MS technique.展开更多
Non-point source （NPS） pollution is the main threat to regional water quality, and the estimation of NPS pollution load has become an important task for NPS pollution control in China. Combined with geographical inf...Non-point source （NPS） pollution is the main threat to regional water quality, and the estimation of NPS pollution load has become an important task for NPS pollution control in China. Combined with geographical information system （GIS）, the long. term hydrologic impact assessment （L-THIA） model was used to evaluate the temporal.spatial changes of chemical oxygen demand （COD）, total nitrogen （TN） and total phosphorus （TP） in Nansi Lake basin from 2000 to 2010. The results show： 1 ） the estimated COD, TN and TP loads in 2010 are 260017.5, 111607. 7 and 6372.0 t with the relative errors of 2.1%, 2. 0 % and - 8.8 % respectively, and more than 90% concentrated in the raining period from June to September; 2） cultivated land and construction land take up more than 80% of the whole Nansi Lake basin, and the proportions of the three kinds of NPS pollution loads coming from cultivated land and construction land are more than 98%; 3 ） during 2000- 2010, the COD, TN and TP loads increase by 8801. 6, 180.3 and 71.9 t respectively, and become the main impact factors on the water quality of Nansi Lake.展开更多
文摘农业生产营养物质的输出是造成水环境污染的重要原因之一。该文以北京密云水库周边地区为研究区域,基于土地利用、土壤以及降水等下垫面信息,利用长期水文影响评价(T he Long-T erm Hydro log ic Im pact A ssessm en t,L-TH IA)模型,估算研究区内污染物的长期平均输出负荷,并分析其空间分布特征。研究结果表明:不同土地利用类型的污染物输出负荷是不同的,其中以农用地对研究区内非点源污染的影响最大。结果表明,在流域规划和管理中使用L-TH IA模型分析农业非点源污染的空间分布是可行的。
文摘以大亚湾为研究对象,采用3S(GIS、RS和GPS)技术划分了汇水区范围并处理获得土地利用、土壤水文单元及降水等下垫面信息,运用L-THIA模型(Long-term Hydrologic Impact and Non Point Source Pollutant Model)构建了总氮(TN)这一指标的大亚湾汇水区非点源污染模型,并通过径流量与负荷量模拟结果与不同方法计算结果的比对验证了模型的合理性。结果表明,大亚湾陆域非点源TN年均负荷量为2 559 t;土地利用类型中耕地、建设用地和园地的负荷量和单位面积流失强度均较高,是TN流失的主要土地利用类型;汇水区涉及的11个镇(街)中惠州市稔山镇、平海镇对TN负荷量的贡献合计超过50. 0%,占据了77. 7%的TN流失关键源区,是非点源污染防治需重点关注的区域。来源贡献的定量识别和关键源区的空间识别为大亚湾陆域非点源TN污染的有效控制提供了重要的科学依据。
基金Natural Science Foundation of Education Department of Anhui Province,China(No.KJ2013B028)Textile Science and Technology Key Discipline in Anhui Polytechnic University,China
文摘Calix[4]arene derivatives have been reported to possess high selectivity for metal ions.In order to analyze the extraction effect of substituents on Hg^(2+)and Pb^(2+),calix[4]arene derivatives containing hydroxyl,bromoethoxy and 1,11-dioxa-4,8-dithiahendecene were successfully synthesized,with their extraction effectiveness towards Hg^(2+)and Pb^(2+)were evaluated respectively.The results indicated that the phenolic hydroxyl in calix[4]arene improved the extraction ability on Hg^(2+)by promoting the formation of the negative oxygen ions that could bind with Hg^(2+)by coordination and ionic bonds.The extraction ability of 5,17-dinitro-26,28-(1’,11’-dioxa-4’,8’-dithiahendecene)-calix[4]arene(calix[4]arene thia derivative)was improved slightly due to the better coordination capacity for metal ions after introduction of 1,11-dioxa-4,8-dithiahendecene,which was a chelate-binding centre.Regarding to Pb^(2+),only 1,11-dioxa-4,8-dithiahendecene on molecule contributed to extraction due to the coordination bond.Since the metal ion with higher charge-to-radius ratio could coordinate with one ligand more stably,Pb^(2+)with higher charge-to-radius ratio than Hg^(2+)was coordinated and extracted by the calix[4]arene thia derivative more easily.Furthermore,extraction rates of the calix[4]arene thia derivative on both ions(Hg^(2+)and Pb^(2+))increased with the increase of pH value in acidic aqueous system(pH<7).
文摘A new type of ferrocenyl thia crown ethers used as selective ligands to some poisonous metals was synthesized, and the features of their mass spectra in electron ionization mode were summarized as: (1) the strong molecular ion peaks; (2) a characteristic homologous ion series with sequential loss of C 2H 4S or C 2H 4O from M C 5H 5; (3) a new rearrangement reaction of Fe migration; (4) the uncommon loss of alcohol or thiol from the fragments of Fe rearrangement. Some typical fragmentation patterns were discussed in detail with the aid of exact mass measurement and MS/MS technique.
基金National Natural Science Foundation of China(No.41401663)Natural Science Foundation of Shandong Province,China(No.ZR2016EEM18)+1 种基金Science Foundation of Ministry of Education of China(No.12YJC790254)Excellent Young Scholars Research Fund of Shandong Normal University,China
文摘Non-point source （NPS） pollution is the main threat to regional water quality, and the estimation of NPS pollution load has become an important task for NPS pollution control in China. Combined with geographical information system （GIS）, the long. term hydrologic impact assessment （L-THIA） model was used to evaluate the temporal.spatial changes of chemical oxygen demand （COD）, total nitrogen （TN） and total phosphorus （TP） in Nansi Lake basin from 2000 to 2010. The results show： 1 ） the estimated COD, TN and TP loads in 2010 are 260017.5, 111607. 7 and 6372.0 t with the relative errors of 2.1%, 2. 0 % and - 8.8 % respectively, and more than 90% concentrated in the raining period from June to September; 2） cultivated land and construction land take up more than 80% of the whole Nansi Lake basin, and the proportions of the three kinds of NPS pollution loads coming from cultivated land and construction land are more than 98%; 3 ） during 2000- 2010, the COD, TN and TP loads increase by 8801. 6, 180.3 and 71.9 t respectively, and become the main impact factors on the water quality of Nansi Lake.
