Noise removal routines (destriping) were performed on Landsat ETM+ data as adjustments for atmospheric and distortion factors, prior to further image enhancement and interpretation. The image enhancement techniques w...Noise removal routines (destriping) were performed on Landsat ETM+ data as adjustments for atmospheric and distortion factors, prior to further image enhancement and interpretation. The image enhancement techniques were contrast stretching, density slicing, spatial filtering, Fourier analysis, brightness inversion, band combinations, and band ratioing. It has been revealed that, owing to the presence of gossans at Paishanlou, the mixture of iron oxide and clay minerals affects the spectral reflectance in satellite data. The mineral and hydrothermal composite images with band ratios 5/7+5/4+3/1 RGB and 5/7+3/1+4/3 RGB, respectively, yielded the best results for their sensitivity to lithologic variables, and lack of statistical redundancy. Ratio 3/1 clearly highlighted ferric (Fe 3+ ) iron; 5/4 depicted ferrous (Fe 2+ ) iron, and 5/7 depicted clays, carbonates, and hydroxyl bearing minerals. Vegetation was also successfully discriminated by ratio 5/7. Finally, coupled with field surveys, petrographical and geochemical data, the observed anomalies led to the discovery of three new sites, which are gold mineralized. The prime objective of this study was to map supergene and/or hypogene signatures in the gold mineralized areas using Landsat ETM+ data at Paishanlou.展开更多
The Nahran area is located in the Northeast of Zanjan in the Northwest of Iran. This area with 20,000 km2 is part of the Tarom volcanic-plutonic zone which lies between the longitudes 49°7'7.8"E and 36&#...The Nahran area is located in the Northeast of Zanjan in the Northwest of Iran. This area with 20,000 km2 is part of the Tarom volcanic-plutonic zone which lies between the longitudes 49°7'7.8"E and 36°41'25.74"E near to the Nahran village. The Nahran altered zone is part of large-scale syncline, which is oriented from Sirdan to Altinkosh with an axial length of 9 km. A systematic study of petrographical and geochemical data of Nahran samples reveals they are andesite, trachyandesite to dacite composition and have metaluminous to peraluminous and calc-alkaline affinity. Four alteration zones of propylitic, medium and advanced argillic and silicific zones could be identified in the area. According to our finding, combination of both supergene and hypogene process has an effective role in the development of alteration in the Nahran alteration zone.展开更多
Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed. It consists of six endemic stygobiont and troglo-biont crustaceans and other...Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed. It consists of six endemic stygobiont and troglo-biont crustaceans and other arthropods and two species still with unclear status. The taxonomic list is followed by brief discussions on the systematics of the species as well as by a few comments concerning the eventual broader zoogeographical and speleological implications of the Ayyalon faunistic findings, as they appeared in literature.展开更多
A preliminary survey of silver isotopic composition in four polymetallic ores in eastern China shows a larger variation inδ^(109)Ag from-0.014‰to+0.983‰,which is within the total ranges for the entire respective or...A preliminary survey of silver isotopic composition in four polymetallic ores in eastern China shows a larger variation inδ^(109)Ag from-0.014‰to+0.983‰,which is within the total ranges for the entire respective ore deposit types worldwide.The diversity of silver isotopic compositions in oredeposits reported here and previous studies seemed to preclude simple isotopic links to particular sources,but reflected the silver isotope fractionation in transport-and deposit-related processes instead.Theδ^(109)Ag values in supergene samples from the Qixiashan Pb-Zn-Ag polymetallic deposit are more positive,in consistent with the statistical δ^(109)Ag distribution from-0.4‰to+2.2‰in 36 pieces of supergene ore samples around the World,which reflects the diverse controls on silver isotope fractionation from the first-order thermodynamic effect,reduction-mediated reaction,remobilization of silver with surficial low-temperature weathering processes.The hypogene samples in Dazhuangzi orogenic Au-Ag ore deposit,have δ^(109)Ag values close to 0,which implies that equilibrium partitioning associated with metal sources at the high-temperature does not result in a resolvable difference in silver isotopic compositions.By contrast,the hypogene samples which are dominated by pyrite without visible silver minerals (i.e.,skarn iron ore deposit in Edongnan) have shown the largest variation range of δ^(109)Ag,followed by that from the porphyry copper ore in Zijinshan.It could be concluded that the surface adsorption and/or lattice substitution are important factors to control Ag isotope fractionation in oreforming processes,especially for skarn deposits with only pyrite.The perspective of silver isotope shows great potentials to understand the processes that lead to the concentrations of metals to economic levels and to constrain the physicochemical conditions during ore-mineralization in metallic ore-deposits.展开更多
According to the features of geophysics, experimental petrology, granite geology and geochemistry, the differentiations of ore-bearing granitic magmas are discussed. It is put forward that only the supergene different...According to the features of geophysics, experimental petrology, granite geology and geochemistry, the differentiations of ore-bearing granitic magmas are discussed. It is put forward that only the supergene differentiations of ore-bearing granitic magma might exist, instead of the hypogene one of the magma. Based on it, a supergene differentiation model for the ore-bearlng granitic magma is presented.展开更多
甲状旁腺素能增加人体骨密度和骨强度,是治疗骨质疏松症最有效的多肽类药物之一,但至今缺乏具有相应功能的小分子药物。根据计算机辅助药物设计原理,采用Discovery Studio 2.5软件包,以14个甲状旁腺素(PTH)受体激动剂及其突变类似物为...甲状旁腺素能增加人体骨密度和骨强度,是治疗骨质疏松症最有效的多肽类药物之一,但至今缺乏具有相应功能的小分子药物。根据计算机辅助药物设计原理,采用Discovery Studio 2.5软件包,以14个甲状旁腺素(PTH)受体激动剂及其突变类似物为训练集,利用活性构象限制的方法,采用HypoGen算法构建出具有活性预测功能的3D药效团模型。其中最好的药效团模型含有1个阳离子基团(PI),3个疏水中心(H)和1个氢键供体(HBD)。同时应用该模型成功预测出16个测试集分子的活性,经交叉验证表明该模型达到95%的置信水平,具有良好的活性预测能力。该药效团可以用于后续抗骨质疏松症小分子药物的筛选,指导相应的药物优化,同时所采用的限制构象的药效团生产方法为基于多肽的药物设计提供了一个新的思路。展开更多
文摘Noise removal routines (destriping) were performed on Landsat ETM+ data as adjustments for atmospheric and distortion factors, prior to further image enhancement and interpretation. The image enhancement techniques were contrast stretching, density slicing, spatial filtering, Fourier analysis, brightness inversion, band combinations, and band ratioing. It has been revealed that, owing to the presence of gossans at Paishanlou, the mixture of iron oxide and clay minerals affects the spectral reflectance in satellite data. The mineral and hydrothermal composite images with band ratios 5/7+5/4+3/1 RGB and 5/7+3/1+4/3 RGB, respectively, yielded the best results for their sensitivity to lithologic variables, and lack of statistical redundancy. Ratio 3/1 clearly highlighted ferric (Fe 3+ ) iron; 5/4 depicted ferrous (Fe 2+ ) iron, and 5/7 depicted clays, carbonates, and hydroxyl bearing minerals. Vegetation was also successfully discriminated by ratio 5/7. Finally, coupled with field surveys, petrographical and geochemical data, the observed anomalies led to the discovery of three new sites, which are gold mineralized. The prime objective of this study was to map supergene and/or hypogene signatures in the gold mineralized areas using Landsat ETM+ data at Paishanlou.
文摘The Nahran area is located in the Northeast of Zanjan in the Northwest of Iran. This area with 20,000 km2 is part of the Tarom volcanic-plutonic zone which lies between the longitudes 49°7'7.8"E and 36°41'25.74"E near to the Nahran village. The Nahran altered zone is part of large-scale syncline, which is oriented from Sirdan to Altinkosh with an axial length of 9 km. A systematic study of petrographical and geochemical data of Nahran samples reveals they are andesite, trachyandesite to dacite composition and have metaluminous to peraluminous and calc-alkaline affinity. Four alteration zones of propylitic, medium and advanced argillic and silicific zones could be identified in the area. According to our finding, combination of both supergene and hypogene process has an effective role in the development of alteration in the Nahran alteration zone.
文摘Seven years after the discovery of the chemoautotrophic sulfidic groundwater site of the Ayyalon cave, its macrofauna can be fully reviewed. It consists of six endemic stygobiont and troglo-biont crustaceans and other arthropods and two species still with unclear status. The taxonomic list is followed by brief discussions on the systematics of the species as well as by a few comments concerning the eventual broader zoogeographical and speleological implications of the Ayyalon faunistic findings, as they appeared in literature.
基金supported by the National Natural Science Foundations of China(Nos.41973005,41673001)China National Space Administration(CNSA)(No.D020205)。
文摘A preliminary survey of silver isotopic composition in four polymetallic ores in eastern China shows a larger variation inδ^(109)Ag from-0.014‰to+0.983‰,which is within the total ranges for the entire respective ore deposit types worldwide.The diversity of silver isotopic compositions in oredeposits reported here and previous studies seemed to preclude simple isotopic links to particular sources,but reflected the silver isotope fractionation in transport-and deposit-related processes instead.Theδ^(109)Ag values in supergene samples from the Qixiashan Pb-Zn-Ag polymetallic deposit are more positive,in consistent with the statistical δ^(109)Ag distribution from-0.4‰to+2.2‰in 36 pieces of supergene ore samples around the World,which reflects the diverse controls on silver isotope fractionation from the first-order thermodynamic effect,reduction-mediated reaction,remobilization of silver with surficial low-temperature weathering processes.The hypogene samples in Dazhuangzi orogenic Au-Ag ore deposit,have δ^(109)Ag values close to 0,which implies that equilibrium partitioning associated with metal sources at the high-temperature does not result in a resolvable difference in silver isotopic compositions.By contrast,the hypogene samples which are dominated by pyrite without visible silver minerals (i.e.,skarn iron ore deposit in Edongnan) have shown the largest variation range of δ^(109)Ag,followed by that from the porphyry copper ore in Zijinshan.It could be concluded that the surface adsorption and/or lattice substitution are important factors to control Ag isotope fractionation in oreforming processes,especially for skarn deposits with only pyrite.The perspective of silver isotope shows great potentials to understand the processes that lead to the concentrations of metals to economic levels and to constrain the physicochemical conditions during ore-mineralization in metallic ore-deposits.
文摘According to the features of geophysics, experimental petrology, granite geology and geochemistry, the differentiations of ore-bearing granitic magmas are discussed. It is put forward that only the supergene differentiations of ore-bearing granitic magma might exist, instead of the hypogene one of the magma. Based on it, a supergene differentiation model for the ore-bearlng granitic magma is presented.
文摘甲状旁腺素能增加人体骨密度和骨强度,是治疗骨质疏松症最有效的多肽类药物之一,但至今缺乏具有相应功能的小分子药物。根据计算机辅助药物设计原理,采用Discovery Studio 2.5软件包,以14个甲状旁腺素(PTH)受体激动剂及其突变类似物为训练集,利用活性构象限制的方法,采用HypoGen算法构建出具有活性预测功能的3D药效团模型。其中最好的药效团模型含有1个阳离子基团(PI),3个疏水中心(H)和1个氢键供体(HBD)。同时应用该模型成功预测出16个测试集分子的活性,经交叉验证表明该模型达到95%的置信水平,具有良好的活性预测能力。该药效团可以用于后续抗骨质疏松症小分子药物的筛选,指导相应的药物优化,同时所采用的限制构象的药效团生产方法为基于多肽的药物设计提供了一个新的思路。
