Talc is a hydroxyled, magnesium-rich, layered silicate that has the ideal chemical formula Mg3Si4O10(OH)2. Due to its unique properties, such as softness, chemical inertness, high thermal stability, low electrical con...Talc is a hydroxyled, magnesium-rich, layered silicate that has the ideal chemical formula Mg3Si4O10(OH)2. Due to its unique properties, such as softness, chemical inertness, high thermal stability, low electrical conductivity, lamellar habit, adsorption properties, and occurrence of a wide range of particle sizes that can be easily reduced by milling and high specific surface area, talc is widely used in many industries. A stratified deposit of unusual black talc, an occurrence of talc estimated to be more than half a billion tons, was found exposed in the late Neoproterozoic Dengying Formation, located in Guangfeng County, Jiangxi Province, southeastern China. The ores occur primarily as oolitic structures (Fig. 1). The mineralogical and geochemical characteristics of the ores were investigated by using multiple techniques. The ores were found to mainly consist of talc (30%–70%), dolomite, quartz, and magnesite. Most of talc crystals are ultrafine (with an average crystallite size of smaller than 5 μm) and appear as irregular broken or distorted lamellar flakes. The total organic carbon (TOC) content of the black talc ore samples is generally lower than 1.0%. Electron-microprobe analysis (EPMA) revealed low contents of Na, K, Ca and Mn, Fe, Ni, Al in the talc oolitic particles. The talc ores have low contents of toxic elements and relatively high contents of Li and Zn. The infrared spectrum of the black talc is similar to that of white talc from Trimouns (Pyrenees, France), and their Brunauer–Emmett-Teller (BET) specific surface areas, ranging from 15.7 to 23.2 m2/g, is much higher than those of white talc (normally lower than 5.0 m2/g), which may be due to the small size of the talc crystals.展开更多
The base of non-pollution agricultural products is a prerequisite for the non-pollution agricultural production. Based on two factors, i.e., irrigation water and soil, the environmental quality of Yilan county＇s base...The base of non-pollution agricultural products is a prerequisite for the non-pollution agricultural production. Based on two factors, i.e., irrigation water and soil, the environmental quality of Yilan county＇s base of non-pollution agricultural products was evaluated by single pollution index. The main monitoring items included the content of Hg, Se, Cr, Pb, fluoride, and so on, and the evaluating results showed Pi〈1 which indicated that this area was fit for developing not only non-pollution products but also greenfood of A level.展开更多
Total concentrations of arsenic, lead, cadmium, mercury, nickel, chromium, and copper in the soils from near a coal mine area in southwest Guizhou, China, were measured to evaluate the level of contamination, and the ...Total concentrations of arsenic, lead, cadmium, mercury, nickel, chromium, and copper in the soils from near a coal mine area in southwest Guizhou, China, were measured to evaluate the level of contamination, and the potential ecological risks posed by the heavy metals were quantitatively estimated. Results reveal that all heavy metals/metalloid exceeded the background values for soil environmental quality of heavy metals in Guizhou area. Geo-accumulation index(I_(geo)) showed that arsenic had the highest contamination level(I_(geo)=4) among the seven heavy metals/metalloid, and the contamination levels of mercury and lead were also relatively high(I_(geo)=3). Pearson correlation and cluster analysis identified that mercury, copper and arsenic had a relationship, and their presence might be mainly related to mining activity, coal and oil combustion, and vehicle emissions. Improved Nemerow index indicated that the overall level of heavy metal contamination in the studied area ranged from moderately–heavily contaminated to heavily contaminated level. Potential ecological risk index(R_I) analysis manifested that the whole ecological risk level ranged from high degree to very high degree(325.30≤R_I≤801.02) in the studied soil samples, and the potential ecological risk factors (E_r^i) of heavy metals/metalloid were as follows: Hg > As > Cd > Pb > Cu > Ni > Cr, and the E_r^i of Hg and As reached very high risk grade.展开更多
In early morning of Aug 8th, 2010, the rain-triggered tremendous debris flows broke out simultaneously at the Sanyanyu ravine and Luojiayu ravine, which locate in the north part of Zhouqu County town. The debris flow ...In early morning of Aug 8th, 2010, the rain-triggered tremendous debris flows broke out simultaneously at the Sanyanyu ravine and Luojiayu ravine, which locate in the north part of Zhouqu County town. The debris flow is the most severe event of the same kind of disasters in the past sixty years in China, which caused great losses of people's lives and properties. Based on field investigation, remote sensing image interpretation and analysis of local climatological data, the local topographical conditions, active tectonic movement, massive debris source and torrential rains were the main formation causes which induced the catastrophic debris flows. Moreover, detailed geological surveys were carried out following the disaster, the other geological potential hazard sites were found out, and the geological and seismic hazard assessment has been put into practice. At last, scientific and appropriate countermeasures have been suggested to prevent and mitigate the extraordinarily serious debris flow.展开更多
Tumen region is situated in the northwest of Yiyuan county, Shandong province, about 130 km to the east of Jinan city, the province captial. The geographical coordinates are 118°33′E longitude and 36°04′N ...Tumen region is situated in the northwest of Yiyuan county, Shandong province, about 130 km to the east of Jinan city, the province captial. The geographical coordinates are 118°33′E longitude and 36°04′N latitude. The modern climate is a warm temperate monsoon forest type, with annual mean temperature of 13℃ and annual mean precipitation of 767 mm . The aridity is 11-- 3.0. So this region is the transitional environment between semiarid and展开更多
分别从性状鉴别、粉末显微鉴别、薄层色谱鉴别、水分、总灰分、浸出物检查、总酸含量测定等方面,比较了7个采样点息半夏(Pinellia ternate(Thunb.)Breit of Xixian county)的质量。结果表明,7个采样点息半夏粉末显微特征、薄层色谱一致...分别从性状鉴别、粉末显微鉴别、薄层色谱鉴别、水分、总灰分、浸出物检查、总酸含量测定等方面,比较了7个采样点息半夏(Pinellia ternate(Thunb.)Breit of Xixian county)的质量。结果表明,7个采样点息半夏粉末显微特征、薄层色谱一致;但性状、水分、总灰分、浸出物和总酸含量有差异。其种源、繁育方式、野生环境、培育条件对息半夏质量有影响。展开更多
Huanglong (yellow dra(?)) Ravine is located in the northeast part of Songpan county, Sichuan province, and 28 km away from the county town (Fig. 1). Because of its magnificant tufa flow, colorful pools and rimstone da...Huanglong (yellow dra(?)) Ravine is located in the northeast part of Songpan county, Sichuan province, and 28 km away from the county town (Fig. 1). Because of its magnificant tufa flow, colorful pools and rimstone dams, it has become a famous scenic spot and typical site of alpine karst.展开更多
文摘Talc is a hydroxyled, magnesium-rich, layered silicate that has the ideal chemical formula Mg3Si4O10(OH)2. Due to its unique properties, such as softness, chemical inertness, high thermal stability, low electrical conductivity, lamellar habit, adsorption properties, and occurrence of a wide range of particle sizes that can be easily reduced by milling and high specific surface area, talc is widely used in many industries. A stratified deposit of unusual black talc, an occurrence of talc estimated to be more than half a billion tons, was found exposed in the late Neoproterozoic Dengying Formation, located in Guangfeng County, Jiangxi Province, southeastern China. The ores occur primarily as oolitic structures (Fig. 1). The mineralogical and geochemical characteristics of the ores were investigated by using multiple techniques. The ores were found to mainly consist of talc (30%–70%), dolomite, quartz, and magnesite. Most of talc crystals are ultrafine (with an average crystallite size of smaller than 5 μm) and appear as irregular broken or distorted lamellar flakes. The total organic carbon (TOC) content of the black talc ore samples is generally lower than 1.0%. Electron-microprobe analysis (EPMA) revealed low contents of Na, K, Ca and Mn, Fe, Ni, Al in the talc oolitic particles. The talc ores have low contents of toxic elements and relatively high contents of Li and Zn. The infrared spectrum of the black talc is similar to that of white talc from Trimouns (Pyrenees, France), and their Brunauer–Emmett-Teller (BET) specific surface areas, ranging from 15.7 to 23.2 m2/g, is much higher than those of white talc (normally lower than 5.0 m2/g), which may be due to the small size of the talc crystals.
基金Supported by Science and Technology Projects of Heilongjiang Province(GB04B717-06)
文摘The base of non-pollution agricultural products is a prerequisite for the non-pollution agricultural production. Based on two factors, i.e., irrigation water and soil, the environmental quality of Yilan county＇s base of non-pollution agricultural products was evaluated by single pollution index. The main monitoring items included the content of Hg, Se, Cr, Pb, fluoride, and so on, and the evaluating results showed Pi〈1 which indicated that this area was fit for developing not only non-pollution products but also greenfood of A level.
基金美国Florida Sea Grant College Program 2012-2013:A Spatial-Temporal Econometric Model to Estimate Costs and Benefits of Sea-Level Rise Adaptation Strategies资助
基金Project(21467005)supported by the National Natural Science Foundation of China
文摘Total concentrations of arsenic, lead, cadmium, mercury, nickel, chromium, and copper in the soils from near a coal mine area in southwest Guizhou, China, were measured to evaluate the level of contamination, and the potential ecological risks posed by the heavy metals were quantitatively estimated. Results reveal that all heavy metals/metalloid exceeded the background values for soil environmental quality of heavy metals in Guizhou area. Geo-accumulation index(I_(geo)) showed that arsenic had the highest contamination level(I_(geo)=4) among the seven heavy metals/metalloid, and the contamination levels of mercury and lead were also relatively high(I_(geo)=3). Pearson correlation and cluster analysis identified that mercury, copper and arsenic had a relationship, and their presence might be mainly related to mining activity, coal and oil combustion, and vehicle emissions. Improved Nemerow index indicated that the overall level of heavy metal contamination in the studied area ranged from moderately–heavily contaminated to heavily contaminated level. Potential ecological risk index(R_I) analysis manifested that the whole ecological risk level ranged from high degree to very high degree(325.30≤R_I≤801.02) in the studied soil samples, and the potential ecological risk factors (E_r^i) of heavy metals/metalloid were as follows: Hg > As > Cd > Pb > Cu > Ni > Cr, and the E_r^i of Hg and As reached very high risk grade.
基金Foundation item： Projects（40902094, 50978239） supported by the National Natural Science Foundation of China Project（20121ESLZ01） supported by the Institute of Earthquake Prediction, China Earthquake Administration
文摘In early morning of Aug 8th, 2010, the rain-triggered tremendous debris flows broke out simultaneously at the Sanyanyu ravine and Luojiayu ravine, which locate in the north part of Zhouqu County town. The debris flow is the most severe event of the same kind of disasters in the past sixty years in China, which caused great losses of people's lives and properties. Based on field investigation, remote sensing image interpretation and analysis of local climatological data, the local topographical conditions, active tectonic movement, massive debris source and torrential rains were the main formation causes which induced the catastrophic debris flows. Moreover, detailed geological surveys were carried out following the disaster, the other geological potential hazard sites were found out, and the geological and seismic hazard assessment has been put into practice. At last, scientific and appropriate countermeasures have been suggested to prevent and mitigate the extraordinarily serious debris flow.
文摘Tumen region is situated in the northwest of Yiyuan county, Shandong province, about 130 km to the east of Jinan city, the province captial. The geographical coordinates are 118°33′E longitude and 36°04′N latitude. The modern climate is a warm temperate monsoon forest type, with annual mean temperature of 13℃ and annual mean precipitation of 767 mm . The aridity is 11-- 3.0. So this region is the transitional environment between semiarid and
文摘分别从性状鉴别、粉末显微鉴别、薄层色谱鉴别、水分、总灰分、浸出物检查、总酸含量测定等方面,比较了7个采样点息半夏(Pinellia ternate(Thunb.)Breit of Xixian county)的质量。结果表明,7个采样点息半夏粉末显微特征、薄层色谱一致;但性状、水分、总灰分、浸出物和总酸含量有差异。其种源、繁育方式、野生环境、培育条件对息半夏质量有影响。
文摘Huanglong (yellow dra(?)) Ravine is located in the northeast part of Songpan county, Sichuan province, and 28 km away from the county town (Fig. 1). Because of its magnificant tufa flow, colorful pools and rimstone dams, it has become a famous scenic spot and typical site of alpine karst.
