As is known to all, theory of invariant metric is very important inseveral complex analysis.The Bergman, Caratheodory and Kobayashi metrics are important biholomorphic. invariants.They play very important role in stud...As is known to all, theory of invariant metric is very important inseveral complex analysis.The Bergman, Caratheodory and Kobayashi metrics are important biholomorphic. invariants.They play very important role in studying the boundary geometry of the domain and biholo-morphic mappings extending smoothly to the boundaries of the relevant domains.展开更多
Based on the complex correlation between the geochemical element distribution patterns at the surface and the types of bedrock and the powerful capabilities in capturing subtle of machine learning algorithms,four mach...Based on the complex correlation between the geochemical element distribution patterns at the surface and the types of bedrock and the powerful capabilities in capturing subtle of machine learning algorithms,four machine learning algorithms,namely,decision tree(DT),random forest(RF),XGBoost(XGB),and LightGBM(LGBM),were implemented for the lithostratigraphic classification and lithostratigraphic prediction of a quaternary coverage area based on stream sediment geochemical sampling data in the Chahanwusu River of Dulan County,Qinghai Province,China.The local Moran’s I to represent the features of spatial autocorrelations,and terrain factors to represent the features of surface geological processes,were calculated as additional features.The accuracy,precision,recall,and F1 scores were chosen as the evaluation indices and Voronoi diagrams were applied for visualization.The results indicate that XGB and LGBM models both performed well.They not only obtained relatively satisfactory classification performance but also predicted lithostratigraphic types of the Quaternary coverage area that are essentially consistent with their neighborhoods which have the known types.It is feasible to classify the lithostratigraphic types through the concentrations of geochemical elements in the sediments,and the XGB and LGBM algorithms are recommended for lithostratigraphic classification.展开更多
The cultural and geomorphological heritages in Playas as a key address to find out past fluctuations called geotop. Iran is strategically located on an important trade route （Silk Road） between four cradles of civil...The cultural and geomorphological heritages in Playas as a key address to find out past fluctuations called geotop. Iran is strategically located on an important trade route （Silk Road） between four cradles of civilization namely, Babylon, Mesopotamia, Indus and Yangtze （Chinese）. Iran is grafting point of four human civilizations which creates Persian civilization about 4,000 years ago. The Lut Desert and Dasht-e Kavir located the central and eastern Iran have been focal points for human settlements since 7,000 years ago. The geoarcheological findings on the Siyalk hills of Kashan located in the Dasht-e Kavir and Jiroft region located in the Lut desert are confirmations for human settlement since more than 7,000 years ago. Shorehzar that is a Persian equivalent word for Arabic word of Sabkha is considered as a Playa geomorphic type which involves precious evidences of quaternary fluctuations. In this article, geomorphological and paleoenvironmental investigations are integrated to provide a framework of environmental change for the late Pleistocene and early-mid Holocene periods in the main deserts of Iran, Lut. In this article based on main geotops of Lut, the quaternary evolutions have been discussed. The investigations are showing that Playas were bed of civilization in Iran Deserts.展开更多
基金Supported by NSFC(No.10171068,No.10071051),NSF of Beijing(No.1012004)and Planned Project for the Development of Science and Technology,Beijing Eduction Committee.
文摘As is known to all, theory of invariant metric is very important inseveral complex analysis.The Bergman, Caratheodory and Kobayashi metrics are important biholomorphic. invariants.They play very important role in studying the boundary geometry of the domain and biholo-morphic mappings extending smoothly to the boundaries of the relevant domains.
基金Projects(41772348,42072326)supported by the National Natural Science Foundation of ChinaProject(2017YFC0601503)supported by the National Key Research and Development Program,China。
文摘Based on the complex correlation between the geochemical element distribution patterns at the surface and the types of bedrock and the powerful capabilities in capturing subtle of machine learning algorithms,four machine learning algorithms,namely,decision tree(DT),random forest(RF),XGBoost(XGB),and LightGBM(LGBM),were implemented for the lithostratigraphic classification and lithostratigraphic prediction of a quaternary coverage area based on stream sediment geochemical sampling data in the Chahanwusu River of Dulan County,Qinghai Province,China.The local Moran’s I to represent the features of spatial autocorrelations,and terrain factors to represent the features of surface geological processes,were calculated as additional features.The accuracy,precision,recall,and F1 scores were chosen as the evaluation indices and Voronoi diagrams were applied for visualization.The results indicate that XGB and LGBM models both performed well.They not only obtained relatively satisfactory classification performance but also predicted lithostratigraphic types of the Quaternary coverage area that are essentially consistent with their neighborhoods which have the known types.It is feasible to classify the lithostratigraphic types through the concentrations of geochemical elements in the sediments,and the XGB and LGBM algorithms are recommended for lithostratigraphic classification.
文摘The cultural and geomorphological heritages in Playas as a key address to find out past fluctuations called geotop. Iran is strategically located on an important trade route （Silk Road） between four cradles of civilization namely, Babylon, Mesopotamia, Indus and Yangtze （Chinese）. Iran is grafting point of four human civilizations which creates Persian civilization about 4,000 years ago. The Lut Desert and Dasht-e Kavir located the central and eastern Iran have been focal points for human settlements since 7,000 years ago. The geoarcheological findings on the Siyalk hills of Kashan located in the Dasht-e Kavir and Jiroft region located in the Lut desert are confirmations for human settlement since more than 7,000 years ago. Shorehzar that is a Persian equivalent word for Arabic word of Sabkha is considered as a Playa geomorphic type which involves precious evidences of quaternary fluctuations. In this article, geomorphological and paleoenvironmental investigations are integrated to provide a framework of environmental change for the late Pleistocene and early-mid Holocene periods in the main deserts of Iran, Lut. In this article based on main geotops of Lut, the quaternary evolutions have been discussed. The investigations are showing that Playas were bed of civilization in Iran Deserts.
