A 51.85-m tim core collected from site DT001 （accumulation rate 127 kgm^-2a^-1, mean annual temperature -33.1 ℃） on Princess Elizabeth Land, East Antarctica, during the 1996-97 Chinese First Antarctic Inland Expedi...A 51.85-m tim core collected from site DT001 （accumulation rate 127 kgm^-2a^-1, mean annual temperature -33.1 ℃） on Princess Elizabeth Land, East Antarctica, during the 1996-97 Chinese First Antarctic Inland Expedition has been analyzed for chemical composition and oxygen isotope ratio. A comparison between the seasonal variations of major ions was carried out in order to reduce the dating uncertainty, using the volcanic markers as time constrains. A deposition period of 251 years was determined. The calculated accumulation rates display an increasing trend before 1820, while after 1820, the trend of the accumulation is not obvious. Overall, temperature change in the region shows a slight increasing trend over the past 250 years. But, notably, a temperature decline of -2 ℃ is observed from 1860 to the present. This feature, at odds with the warming trend over the past century recorded in both hemispheres, likely reflects a regional characteristic related to the lack of a high latitude/low latitude link in the Southern Hemisphere circulation patterns. The results of the glaciochemical records of the firn core show that the mean concentrations of Cl^-, Na^＋ and Mg^2＋ are similar to those reported from other sites in East Antarctica. However, the mean concentration of Ca^2＋ is much higher than that reported from other regions, suggesting the influence of the strong local terrestrial sources in Princess Elizabeth Land. There is no evidence of a positive correlation between NO3^- concentrations and solar activity （11-year solar cycle and solar cycle length）, although solar proton events may account for some of the NO3^- peak values in the record.展开更多
以贵州省某厂的废水污染农田土壤为例,通过现场访谈、专家咨询、监测分析和方案对比等方法,从消除危险、污染场地修复及期间生态功能损失对污染场地进行环境污染损害评估。经测算,污染农田面积约40000 m 2,评估区域土壤均受到不同程度...以贵州省某厂的废水污染农田土壤为例,通过现场访谈、专家咨询、监测分析和方案对比等方法,从消除危险、污染场地修复及期间生态功能损失对污染场地进行环境污染损害评估。经测算,污染农田面积约40000 m 2,评估区域土壤均受到不同程度的重金属污染:一号区域土壤全部为重度污染;二号区域91%面积的土壤呈重度污染,7%的土壤为中度污染,轻微和轻度污染仅占2%。污染农田的农作物特别是稻米的重金属含量超标情况较严重,长期食用潜在的人体健康风险超过可接受水平。最终确认污染损害费用估算约5360570元。展开更多
The detailed electrical conductivity measure- ment (ECM), trace chemical compositions and microparti- cles concentration analysis are performed for BH8 ice core from the depth of 126.0m to 130.0m at Vostok Station. At...The detailed electrical conductivity measure- ment (ECM), trace chemical compositions and microparti- cles concentration analysis are performed for BH8 ice core from the depth of 126.0m to 130.0m at Vostok Station. At depth 128.7m, a volcanic signal 4726 a B.P. is detected. The volcanic sulphate flux is 95.8 kg·km?2, sulphate peak concen- tration 1352.8 ng·g?1, duration time about 10.1 years, com- parable with some well-known volcanic events. The results indicate that it seems to be a relatively large scale, long last- ing volcanic signal with farther volcanic origin.展开更多
基金The Key International Cooperation Project of the Ministry of Science and Technology of China, No. 2001CB711003 Knowledge Innovation Project of CAS, No.KZCX3-SW-354
文摘A 51.85-m tim core collected from site DT001 （accumulation rate 127 kgm^-2a^-1, mean annual temperature -33.1 ℃） on Princess Elizabeth Land, East Antarctica, during the 1996-97 Chinese First Antarctic Inland Expedition has been analyzed for chemical composition and oxygen isotope ratio. A comparison between the seasonal variations of major ions was carried out in order to reduce the dating uncertainty, using the volcanic markers as time constrains. A deposition period of 251 years was determined. The calculated accumulation rates display an increasing trend before 1820, while after 1820, the trend of the accumulation is not obvious. Overall, temperature change in the region shows a slight increasing trend over the past 250 years. But, notably, a temperature decline of -2 ℃ is observed from 1860 to the present. This feature, at odds with the warming trend over the past century recorded in both hemispheres, likely reflects a regional characteristic related to the lack of a high latitude/low latitude link in the Southern Hemisphere circulation patterns. The results of the glaciochemical records of the firn core show that the mean concentrations of Cl^-, Na^＋ and Mg^2＋ are similar to those reported from other sites in East Antarctica. However, the mean concentration of Ca^2＋ is much higher than that reported from other regions, suggesting the influence of the strong local terrestrial sources in Princess Elizabeth Land. There is no evidence of a positive correlation between NO3^- concentrations and solar activity （11-year solar cycle and solar cycle length）, although solar proton events may account for some of the NO3^- peak values in the record.
文摘以贵州省某厂的废水污染农田土壤为例,通过现场访谈、专家咨询、监测分析和方案对比等方法,从消除危险、污染场地修复及期间生态功能损失对污染场地进行环境污染损害评估。经测算,污染农田面积约40000 m 2,评估区域土壤均受到不同程度的重金属污染:一号区域土壤全部为重度污染;二号区域91%面积的土壤呈重度污染,7%的土壤为中度污染,轻微和轻度污染仅占2%。污染农田的农作物特别是稻米的重金属含量超标情况较严重,长期食用潜在的人体健康风险超过可接受水平。最终确认污染损害费用估算约5360570元。
基金This work was supported by the China Scholarship Council (CSC)the National Natural Science Foundation of China (Grant Nos.40203013 and 4027 1026) the Brazilian National Council for Scien-tifice ind Technological Developnient (CNPq).
文摘The detailed electrical conductivity measure- ment (ECM), trace chemical compositions and microparti- cles concentration analysis are performed for BH8 ice core from the depth of 126.0m to 130.0m at Vostok Station. At depth 128.7m, a volcanic signal 4726 a B.P. is detected. The volcanic sulphate flux is 95.8 kg·km?2, sulphate peak concen- tration 1352.8 ng·g?1, duration time about 10.1 years, com- parable with some well-known volcanic events. The results indicate that it seems to be a relatively large scale, long last- ing volcanic signal with farther volcanic origin.
