The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic m...The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic matter(OM)enrichment throughout this period is still controversial.Based on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM accumulation.Five Phases are distinguished based on the TOC and environmental variations.In Phase I,anoxic conditions driven by water restriction enhanced OM preservation.In Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM deposition.During Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation condition.Phase IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic environment.In Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary productivity.Phases I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.展开更多
Ba 1 x Dy x Co 2 Fe 16 O 27 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) was prepared by the solid-state method. The phase structure was studied using powder X-ray diffraction (XRD), the electromagnetic properties were meas...Ba 1 x Dy x Co 2 Fe 16 O 27 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) was prepared by the solid-state method. The phase structure was studied using powder X-ray diffraction (XRD), the electromagnetic properties were measured, and the reflection loss of Dy 3+ -doped ferrite material was calculated using electromagnetic parameters by the transmission line theory. All XRD patterns showed the single phase of the magnetoplumbite barium ferrite without other intermediate phase when x ≤ 0.15. The values of ε′ and ε″ increased slightly with Dy 3+ ions doping. The values of μ″ and μ′ were improved with Dy 3+ doping, exhibiting excellent microwave magnetic performance. The reasons have also been discussed using the electromagnetic theory. Dy substitution could increase microwave-absorbing performance and broaden frequency band (reflection loss (RL) < -10 dB), and the absorbing peak shifted to high-frequency position. When x = 0.2, ferrite layer exhibited the most excellent microwave-absorbing performance at a thin matching thickness of 1.5 mm. The peak value of RL was around -15 dB, and the frequency band (RL < -10 dB) was about 7 GHz (from 8 to 15 GHz).展开更多
基金supported by the Fundamental and Commonwealth Geological Survey of Oil and Gas of China(Grant No.DD 20221662)the National Natural Science Foundation of China(NSFC)Program(Grant No.42302124).
文摘The Late Permian was marked by a series of important geological events and widespread organic-rich black shale depositions,acting as important unconventional hydrocarbon source rocks.However,the mechanism of organic matter(OM)enrichment throughout this period is still controversial.Based on geochemical data,the marine redox conditions,paleogeographic and hydrographic environment,primary productivity,volcanism,and terrigenous input during the Late Permian in the Lower Yangtze region have been studied from the Putaoling section,Chaohu,to provide new insights into OM accumulation.Five Phases are distinguished based on the TOC and environmental variations.In Phase I,anoxic conditions driven by water restriction enhanced OM preservation.In Phase II,euxinic and cycling hydrological environments were the two most substantial controlling factors for the massive OM deposition.During Phase III,intensified terrestrial input potentially diluted the OM in sediment and the presence of oxygen in bottom water weakened the preservation condition.Phase IV was characterized by a relatively higher abundance of mercury(Hg)and TOC(peak at 16.98 wt%),indicating that enhanced volcanism potentially stimulated higher productivity and a euxinic environment.In Phase V,extremely lean OM was preserved as a result of terrestrial dilutions and decreasing primary productivity.Phases I,II and IV are characterized as the most prominent OM-rich zones due to the effective interactions of the controlling factors,namely paleogeographic,hydrographic environment,volcanism,and redox conditions.
基金the University Natural Science Fund of Jiangsu Province, China (No. 10KJB430008)the Advanced Project of the General Reserve Department of PLA for the financial support
文摘Ba 1 x Dy x Co 2 Fe 16 O 27 (x = 0.00, 0.05, 0.10, 0.15, and 0.20) was prepared by the solid-state method. The phase structure was studied using powder X-ray diffraction (XRD), the electromagnetic properties were measured, and the reflection loss of Dy 3+ -doped ferrite material was calculated using electromagnetic parameters by the transmission line theory. All XRD patterns showed the single phase of the magnetoplumbite barium ferrite without other intermediate phase when x ≤ 0.15. The values of ε′ and ε″ increased slightly with Dy 3+ ions doping. The values of μ″ and μ′ were improved with Dy 3+ doping, exhibiting excellent microwave magnetic performance. The reasons have also been discussed using the electromagnetic theory. Dy substitution could increase microwave-absorbing performance and broaden frequency band (reflection loss (RL) < -10 dB), and the absorbing peak shifted to high-frequency position. When x = 0.2, ferrite layer exhibited the most excellent microwave-absorbing performance at a thin matching thickness of 1.5 mm. The peak value of RL was around -15 dB, and the frequency band (RL < -10 dB) was about 7 GHz (from 8 to 15 GHz).
