The 7 ka old Qixiangzhan lava flow(QXZ,Tianchi volcano)represents the last eruptive event before the 946 CE,caldera-forming‘Millennium’eruption(ME).Petrographic,whole rock,mineral composition,Sr-Nd isotopic data on ...The 7 ka old Qixiangzhan lava flow(QXZ,Tianchi volcano)represents the last eruptive event before the 946 CE,caldera-forming‘Millennium’eruption(ME).Petrographic,whole rock,mineral composition,Sr-Nd isotopic data on QXZ show that:(a)the lava consists of two components,constituted by comenditic obsidian fragments immersed in a continuous,aphanitic component;(b)both components have the same geochemical and isotopic variations of the ME magma.The QXZ and ME comendites result from fractional crystallization and crustal assimilation processes.The temperature of the QXZ magma was about 790℃ and the depth of the magma reservoir around 7 km,the same values as estimated for ME.QXZ had a viscosity of 10^(5.5)-10^(9) Pa s and a velocity of 3-10 km/yr.The emplacement time was 0.5-1.6yr and the flow rate 0.48-1.50 m^(3)/s.These values lie within the range estimated for other rhyolitic flows worldwide.The QXZ lava originated through a mixed explosive-effusive activity with the obsidian resulting from the ascent of undercooling,degassing and the fragmentation of magma along the conduit walls,whereas the aphanitic component testifies to the less undercooled and segregated flow at the center of the conduit.The QXZ lava demonstrates the extensive history of the ME magma chamber.展开更多
Cenozoic trachytes are characteristic of some active volcanic fields in China.In particular,the origin and mechanisms of the evolution of trachytes from the Tianchi(Changbaishan)volcano(TV,China/North Korea)are poorly...Cenozoic trachytes are characteristic of some active volcanic fields in China.In particular,the origin and mechanisms of the evolution of trachytes from the Tianchi(Changbaishan)volcano(TV,China/North Korea)are poorly known.Here,we present new geochronological,geochemical and isotopic data on two trachytic suites outcropping on the northern and southern upper slopes of TV.Detailed zircon laser ablation-multicollector-inductively coupled plasma-mass spectrometry(LA-MC-ICP-MS)U-Pb dating,Rb-Sr isochron dating of plagioclase and hornblende,^(40)Ar/^(39)Ar chronology with mineral chemistry,whole-rock element and Sr-Nd-Pb isotope data are used to explore their origins and evolutionary mechanisms during the late Middle Pleistocene.Our data indicate that the trachytes mainly consist of sanidine,orthoclase and plagioclase,with minor albite,quartz and hornblende.They formed at 0.353-0.346 Ma(lava flow from the northern slope)and 0.383-0.311 Ma(lava flow from the southern slope),respectively.The TV trachytes are characterized by high K_(2)O/Na_(2)O and AR values,with low A/CNK and Mg~#values.They are enriched in rare earth elements(REEs;except Eu),depleted in Sr and Ba,crystallizing at 742-858℃.The TV trachytes have high(^(87)Sr/^(86)Sr)_i values(0.70776-0.71195),positiveε_(Nd)(t)values(0.61-2.93)and radiogenic^(206)Pb/^(204)Pb values(17.515-17.806).These values are similar to those of the Pleistocene and Holocene TV trachytes.Geochemical data indicate that they were formed by fractional crystallization from a basaltic melt and assimilated upper crust material.The trace element pattern of the studied trachytes is consistent with an evolution from basaltic melts representative of an enriched mantle source.The vent from which the trachytic magma was erupted probably collapsed inside the caldera during the TV'Millennium'eruption(ME)in 946 AD.The contemporaneous emission of basaltic and trachytic magma during the Middle-Late Pleistocene suggests the coexistence of fissural basaltic volcanism and central-type trachytic volcanism,the latter of which was associated with a magma chamber in the upper crust during the TV cone-construction stage.展开更多
Accurate estimations of animal population size are pivotal for implementing management strategies properly.Recapture technique based on sounds as a specimen identifcation mark has barely been used for marine mammals.H...Accurate estimations of animal population size are pivotal for implementing management strategies properly.Recapture technique based on sounds as a specimen identifcation mark has barely been used for marine mammals.However,inferring abundance estimates from acoustic methods could enhance the accuracy and precision of population size assessments.Here,we tested the possibility of using signature whistles as individual marks for estimating the size of common bottlenose dolphin(Tursiops truncatus)populations.Data were continuously collected for 326 days in 2015–2016,by using a fxed acoustic device located in the Sicily Strait(Italy).The SIGID method was applied to identify Signature Whistles Types(SWTs)over 7,000 h of recordings.Eighty SWTs were detected as long as their stereotyped fundamental frequency contours were repeated in bouts of at least 6 renditions.The mean SWTs monthly recording rate resulted in 0.19(Standard deviation=0.16),with 20 SWTs recorded over 5 or more different encounters(until a maximum of 30 encounters).The Jolly–Seber model(with POPAN formulation)was run in Mark software to estimate the population size.The estimated population size resulted in 171 bottlenose dolphins(95%confdence interval=137–215).Even if the detection and identifcation of signature whistles required crucial precautions,and animals could be detected differently from visual techniques,the population size estimate obtained was comparable with previous results based on physical marks data.These outcomes demonstrated that signature whistles can be considered a strongly effective tool for integrating traditional mark-recapture techniques with fnely estimated dolphins’population abundances.展开更多
劳力士TP52世界帆船锦标赛是顶级水手间的竞技,比赛过程精彩绝伦——争先恐后的起航、高潮迭起的竞技过程、争分夺秒的冲线……一点微小的失误都会被其它船队远远抛在后面。TP52级赛船是世界帆船系列赛的重要一员,劳力士TP52世界帆船锦...劳力士TP52世界帆船锦标赛是顶级水手间的竞技,比赛过程精彩绝伦——争先恐后的起航、高潮迭起的竞技过程、争分夺秒的冲线……一点微小的失误都会被其它船队远远抛在后面。TP52级赛船是世界帆船系列赛的重要一员,劳力士TP52世界帆船锦标赛(Rolex TP52 World Championship)则是52英尺超级帆船系列赛(52 SUPER SERIES)的顶级赛事。展开更多
采用熔体水淬法(水冷法)、气雾化法和单辊熔融纺丝技术(甩带法)制备不同冷却速率的快速凝固过共晶Al-50%Si合金,并通过扫描电子显微镜(scanning electron microscope,SEM)和X射线衍射仪(X-ray diffractometer,XRD)分析了快速凝固与常规...采用熔体水淬法(水冷法)、气雾化法和单辊熔融纺丝技术(甩带法)制备不同冷却速率的快速凝固过共晶Al-50%Si合金,并通过扫描电子显微镜(scanning electron microscope,SEM)和X射线衍射仪(X-ray diffractometer,XRD)分析了快速凝固与常规凝固的差异,以及快速凝固Al-50%Si合金微观组织的演变。结果表明:在水冷的Al-50%Si合金组织中观察到了树枝状的Al相,较大的过冷度导致这种亚共晶组织的形成,此组织属于非稳定状态,且共晶Si完全细化至纤维状;随着冷却速率的增加,在甩带试样中Al相的树枝状组织消失;通过甩带以及气雾化制备的Al-50%Si合金中,初晶Si颗粒被明显细化,由常规凝固的200μm细化至20μm左右,使Si在Al基体中的固溶度增大,造成Al基体晶格发生畸变。展开更多
In this paper,the Multi-Temporal Interferometric Synthetic Aperture Radar(MT-InSAR)technology is adopted to monitor the Line of Sight(LOS)displacement of Fushun West Opencast Coal Mine(FWOCM)and its surrounding areas ...In this paper,the Multi-Temporal Interferometric Synthetic Aperture Radar(MT-InSAR)technology is adopted to monitor the Line of Sight(LOS)displacement of Fushun West Opencast Coal Mine(FWOCM)and its surrounding areas in northeast China using Sentinel-1 Synthetic Aperture Radar(SAR)images acquired from 2018 to 2022.The spatial-temporal evolution of urban subsidence and the south-slope landslide are both analyzed in detail.Comparison with ground measurements and cross-correlation analysis via cross wavelet transform with monthly precipitation data are also conducted,to analyze the influence factors of displacements in FWOCM.The monitoring results show that a subsidence basin appeared in the urban area near the eastern part of the north slope in 2018,with settlement center located at the intersection of E3000 and fault F1.The Qian Tai Shan(QTS)landslide on the south slope,which experienced rapid sliding during 2014 to 2016,presents seasonal deceleration and acceleration with precipitation,with the maximum displacement in vicinity of the Liushan paleochannel.The results of this paper have fully taken in account for the complications of large topographic relief,geological conditions,spatial distribution and temporal evolution characteristics of surface displacements in opencast mining area.The wide range and long time series dynamic monitoring of opencast mine are of great significance to ensure mine safety production and geological disaster prevention in the investigated mining area.展开更多
文章介绍了浮动缸套和平均指示压力(indicated mean effective pressure,IMEP)测量方法,并针对浮动缸套法探究了传感器支座振动对测量结果的影响;采用Matlab软件分析了单自由度滞后阻尼在简谐激励下振动系统的输出力与输入力偏离程度,...文章介绍了浮动缸套和平均指示压力(indicated mean effective pressure,IMEP)测量方法,并针对浮动缸套法探究了传感器支座振动对测量结果的影响;采用Matlab软件分析了单自由度滞后阻尼在简谐激励下振动系统的输出力与输入力偏离程度,以表示测量误差大小。仿真结果表明,增加支座等效弹簧刚度与滞后阻尼系数可以降低传感器测量误差,完善浮动缸套法的测量理论,该方法对浮动缸套结构的改装提供了一定的理论指导。展开更多
基金funded by the National Natural Science Foundation of China(Grant Nos.41972313 and 41790453)the Engineering Research Center of Geothermal Resources Development Technology and Equipment,Ministry of Education,Jilin University。
文摘The 7 ka old Qixiangzhan lava flow(QXZ,Tianchi volcano)represents the last eruptive event before the 946 CE,caldera-forming‘Millennium’eruption(ME).Petrographic,whole rock,mineral composition,Sr-Nd isotopic data on QXZ show that:(a)the lava consists of two components,constituted by comenditic obsidian fragments immersed in a continuous,aphanitic component;(b)both components have the same geochemical and isotopic variations of the ME magma.The QXZ and ME comendites result from fractional crystallization and crustal assimilation processes.The temperature of the QXZ magma was about 790℃ and the depth of the magma reservoir around 7 km,the same values as estimated for ME.QXZ had a viscosity of 10^(5.5)-10^(9) Pa s and a velocity of 3-10 km/yr.The emplacement time was 0.5-1.6yr and the flow rate 0.48-1.50 m^(3)/s.These values lie within the range estimated for other rhyolitic flows worldwide.The QXZ lava originated through a mixed explosive-effusive activity with the obsidian resulting from the ascent of undercooling,degassing and the fragmentation of magma along the conduit walls,whereas the aphanitic component testifies to the less undercooled and segregated flow at the center of the conduit.The QXZ lava demonstrates the extensive history of the ME magma chamber.
基金financially supported by the project of the National Observation and Research Station of the Institute of Geology,China Earthquake Administration(Grant No.NORSCBS22-06)the Youth Science and Technology Development Project of the Jilin Earthquake Agency(Grant No.JZQ-202402)+1 种基金the Earthquake Science and Technology Spark Project(Grant No.XH23013B)the China Scholarship Council(Grant No.202104190014)。
文摘Cenozoic trachytes are characteristic of some active volcanic fields in China.In particular,the origin and mechanisms of the evolution of trachytes from the Tianchi(Changbaishan)volcano(TV,China/North Korea)are poorly known.Here,we present new geochronological,geochemical and isotopic data on two trachytic suites outcropping on the northern and southern upper slopes of TV.Detailed zircon laser ablation-multicollector-inductively coupled plasma-mass spectrometry(LA-MC-ICP-MS)U-Pb dating,Rb-Sr isochron dating of plagioclase and hornblende,^(40)Ar/^(39)Ar chronology with mineral chemistry,whole-rock element and Sr-Nd-Pb isotope data are used to explore their origins and evolutionary mechanisms during the late Middle Pleistocene.Our data indicate that the trachytes mainly consist of sanidine,orthoclase and plagioclase,with minor albite,quartz and hornblende.They formed at 0.353-0.346 Ma(lava flow from the northern slope)and 0.383-0.311 Ma(lava flow from the southern slope),respectively.The TV trachytes are characterized by high K_(2)O/Na_(2)O and AR values,with low A/CNK and Mg~#values.They are enriched in rare earth elements(REEs;except Eu),depleted in Sr and Ba,crystallizing at 742-858℃.The TV trachytes have high(^(87)Sr/^(86)Sr)_i values(0.70776-0.71195),positiveε_(Nd)(t)values(0.61-2.93)and radiogenic^(206)Pb/^(204)Pb values(17.515-17.806).These values are similar to those of the Pleistocene and Holocene TV trachytes.Geochemical data indicate that they were formed by fractional crystallization from a basaltic melt and assimilated upper crust material.The trace element pattern of the studied trachytes is consistent with an evolution from basaltic melts representative of an enriched mantle source.The vent from which the trachytic magma was erupted probably collapsed inside the caldera during the TV'Millennium'eruption(ME)in 946 AD.The contemporaneous emission of basaltic and trachytic magma during the Middle-Late Pleistocene suggests the coexistence of fissural basaltic volcanism and central-type trachytic volcanism,the latter of which was associated with a magma chamber in the upper crust during the TV cone-construction stage.
基金the project“BIOforIU project PONa3_00025-Multidisciplinary Infrastructure for the Study and Development of Marine and Terrestrial Biodiversity in the Perspective of Innovation Union.”Part of the analysis was funded under the National Recovery and Resilience Plan(NRRP),Mission 4 Component 2 Investment 1.4-Call for tender No.3138 of 16 December 2021,rectifed by Decree n.3175 of 18 December 2021 of Italian Ministry of University and Research funded by the European Union-NextGenerationEU,Award Number:Project code CN_00000033,Concession Decree No.1034 of 17 June 2022 adopted by the Italian Ministry of University and Research,Project title"National Biodiversity Future Center-NBFC".
文摘Accurate estimations of animal population size are pivotal for implementing management strategies properly.Recapture technique based on sounds as a specimen identifcation mark has barely been used for marine mammals.However,inferring abundance estimates from acoustic methods could enhance the accuracy and precision of population size assessments.Here,we tested the possibility of using signature whistles as individual marks for estimating the size of common bottlenose dolphin(Tursiops truncatus)populations.Data were continuously collected for 326 days in 2015–2016,by using a fxed acoustic device located in the Sicily Strait(Italy).The SIGID method was applied to identify Signature Whistles Types(SWTs)over 7,000 h of recordings.Eighty SWTs were detected as long as their stereotyped fundamental frequency contours were repeated in bouts of at least 6 renditions.The mean SWTs monthly recording rate resulted in 0.19(Standard deviation=0.16),with 20 SWTs recorded over 5 or more different encounters(until a maximum of 30 encounters).The Jolly–Seber model(with POPAN formulation)was run in Mark software to estimate the population size.The estimated population size resulted in 171 bottlenose dolphins(95%confdence interval=137–215).Even if the detection and identifcation of signature whistles required crucial precautions,and animals could be detected differently from visual techniques,the population size estimate obtained was comparable with previous results based on physical marks data.These outcomes demonstrated that signature whistles can be considered a strongly effective tool for integrating traditional mark-recapture techniques with fnely estimated dolphins’population abundances.
文摘劳力士TP52世界帆船锦标赛是顶级水手间的竞技,比赛过程精彩绝伦——争先恐后的起航、高潮迭起的竞技过程、争分夺秒的冲线……一点微小的失误都会被其它船队远远抛在后面。TP52级赛船是世界帆船系列赛的重要一员,劳力士TP52世界帆船锦标赛(Rolex TP52 World Championship)则是52英尺超级帆船系列赛(52 SUPER SERIES)的顶级赛事。
文摘采用熔体水淬法(水冷法)、气雾化法和单辊熔融纺丝技术(甩带法)制备不同冷却速率的快速凝固过共晶Al-50%Si合金,并通过扫描电子显微镜(scanning electron microscope,SEM)和X射线衍射仪(X-ray diffractometer,XRD)分析了快速凝固与常规凝固的差异,以及快速凝固Al-50%Si合金微观组织的演变。结果表明:在水冷的Al-50%Si合金组织中观察到了树枝状的Al相,较大的过冷度导致这种亚共晶组织的形成,此组织属于非稳定状态,且共晶Si完全细化至纤维状;随着冷却速率的增加,在甩带试样中Al相的树枝状组织消失;通过甩带以及气雾化制备的Al-50%Si合金中,初晶Si颗粒被明显细化,由常规凝固的200μm细化至20μm左右,使Si在Al基体中的固溶度增大,造成Al基体晶格发生畸变。
基金supported by the Natural Science Foundation of China[grant number 42071453]the geological hazard investigation project of Liaoning Province[grant number 2022020700179]the Fund of National Key Laboratory of Science and Technology on Remote Sensing Information and imagery Analysis,Beijing Research Institute of Uranium Geology[grant number 6142A01210407].
文摘In this paper,the Multi-Temporal Interferometric Synthetic Aperture Radar(MT-InSAR)technology is adopted to monitor the Line of Sight(LOS)displacement of Fushun West Opencast Coal Mine(FWOCM)and its surrounding areas in northeast China using Sentinel-1 Synthetic Aperture Radar(SAR)images acquired from 2018 to 2022.The spatial-temporal evolution of urban subsidence and the south-slope landslide are both analyzed in detail.Comparison with ground measurements and cross-correlation analysis via cross wavelet transform with monthly precipitation data are also conducted,to analyze the influence factors of displacements in FWOCM.The monitoring results show that a subsidence basin appeared in the urban area near the eastern part of the north slope in 2018,with settlement center located at the intersection of E3000 and fault F1.The Qian Tai Shan(QTS)landslide on the south slope,which experienced rapid sliding during 2014 to 2016,presents seasonal deceleration and acceleration with precipitation,with the maximum displacement in vicinity of the Liushan paleochannel.The results of this paper have fully taken in account for the complications of large topographic relief,geological conditions,spatial distribution and temporal evolution characteristics of surface displacements in opencast mining area.The wide range and long time series dynamic monitoring of opencast mine are of great significance to ensure mine safety production and geological disaster prevention in the investigated mining area.
文摘文章介绍了浮动缸套和平均指示压力(indicated mean effective pressure,IMEP)测量方法,并针对浮动缸套法探究了传感器支座振动对测量结果的影响;采用Matlab软件分析了单自由度滞后阻尼在简谐激励下振动系统的输出力与输入力偏离程度,以表示测量误差大小。仿真结果表明,增加支座等效弹簧刚度与滞后阻尼系数可以降低传感器测量误差,完善浮动缸套法的测量理论,该方法对浮动缸套结构的改装提供了一定的理论指导。
