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
In this study,ionosonde observations over Fuke(19.5°N,109.1°E),Wuhan(30.5°N,114.4°E),and Mohe(53.5°N,122.3°E)were analyzed to demonstrate the responses of the sporadic E()to the severe at...In this study,ionosonde observations over Fuke(19.5°N,109.1°E),Wuhan(30.5°N,114.4°E),and Mohe(53.5°N,122.3°E)were analyzed to demonstrate the responses of the sporadic E()to the severe atmospheric disturbances caused by the Tonga volcanic eruptions on January 15,2022.The most prominent signature was the disappearance of the layer after~10:00 UT over Wuhan and Fuke,which was attributed to the vertical drift caused by the eruptions.The occurred intermittently after 13:00 UT following the arrival of the tropospheric Lamb wave.To examine the causal mechanism for the intermittence,we also included data of horizontal winds in the mesosphere and lower thermosphere region recorded by the meteor radars at Wuhan and Mohe in this study.The wind disturbances with periods of~20 hours contributed to the formation of the layer in the nighttime on January 15.展开更多
目的评估阿达木单抗联合激素治疗重症药疹的疗效和安全性。方法回顾性分析2023年1月至2024年2月于空军特色医学中心皮肤科住院治疗的16例重症药疹患者的临床资料,根据用药的不同将患者分为激素组(10例)和阿达木单抗联合激素治疗组(联合...目的评估阿达木单抗联合激素治疗重症药疹的疗效和安全性。方法回顾性分析2023年1月至2024年2月于空军特色医学中心皮肤科住院治疗的16例重症药疹患者的临床资料,根据用药的不同将患者分为激素组(10例)和阿达木单抗联合激素治疗组(联合组)(6例)。比较2组药疹皮损面积和严重程度指数(drug eruption area and severity index,DASI)评分;比较2组患者疗效、住院时间、皮疹停止进展时间、激素减量时间、皮肤黏膜痒痛感缓解时间、激素初始剂量、激素最大剂量、皮疹停止进展时激素累积剂量及住院期间激素总剂量;比较2组患者血清铁蛋白、D-二聚体(D-dimer,D-D)、β2微球蛋白水平及不良反应发生情况。结果联合组治疗后DASI评分低于激素组(F=6.618,P=0.023)。联合组治疗后血清铁蛋白水平低于治疗前(P=0.002),激素组治疗后血清铁蛋白水平高于联合组(P=0.046);激素组治疗后D-D水平较治疗前下降(P<0.001);2组治疗前后β2微球蛋白水平差异具有统计学意义(Wald χ^(2)=11.066,P=0.001)。联合组皮疹停止进展时间、皮肤黏膜痒痛感缓解时间、激素减量时间、皮疹停止进展时激素的累积剂量及住院期间激素使用总剂量均低于激素组(t=2.221~3.733,P=0.002~0.043)。2组不良反应发生率差异均无统计学意义(P均>0.05)。结论阿达木单抗联合激素治疗可作为重症药疹的治疗选择,对于病情较重、病程较长和大剂量激素冲击治疗皮疹控制不佳的患者,二者联合使用,可以缩短重症药疹病程,减少激素用量。展开更多
Since the eruption of the Tianchi volcano about 1000 years ago, there have been at least 3 to 5 eruptions of small to moderate size. In addition, hazardous avalanches, rock falls and debris flows have occurred during ...Since the eruption of the Tianchi volcano about 1000 years ago, there have been at least 3 to 5 eruptions of small to moderate size. In addition, hazardous avalanches, rock falls and debris flows have occurred during periods between eruptions. A future eruption of the Tianchi volcano is likely to involve explosive interaction between magma and the caldera lake. The volume of erupted magma is almost in a range of 0.1-0.5 km3. Tephra fallout may damage agriculture in a large area near the volcano. If only 1% of the lake water were ejected during an eruption and then precipitated over an area of 200 km2, the average rainfall would be 100 mm. Moreover, lahars are likely to occur as both tephra and water ejected from the caldera lake fall onto flanks of the volcano. Rocks avalanching into the caldera lake also would bring about grave hazards because seiches would be triggered and lake water with the volume equal to that of the landslide would spill out of the existing breach in the caldera and cause flooding downstream.展开更多
With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery ...With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery of the ozone layer is predicted in this century. However, strong volcanic activity can also cause ozone depletion that might be severe enough to threaten the existence of life on Earth. In this study, a transport model and a coupled chemistry–climate model were used to simulate the impacts of super volcanoes on ozone depletion. The volcanic eruptions in the experiments were the 1991 Mount Pinatubo eruption and a 100 × Pinatubo size eruption. The results show that the percentage of global mean total column ozone depletion in the 2050 RCP8.5 100 × Pinatubo scenario is approximately 6% compared to two years before the eruption and 6.4% in tropics. An identical simulation, 100 × Pinatubo eruption only with natural source ODSs, produces an ozone depletion of 2.5% compared to two years before the eruption, and with 4.4% loss in the tropics. Based on the model results,the reduced ODSs and stratospheric cooling lighten the ozone depletion after super volcanic eruption.展开更多
A 600-year integration performed with the Bergen Climate Model and National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） reanalysis data were used to investigate the impa...A 600-year integration performed with the Bergen Climate Model and National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） reanalysis data were used to investigate the impact of strong tropical volcanic eruptions on the East Asian summer monsoon （EASM） and EASM rainfall.Both the simulation and NCEP/NCAR reanalysis data show a weakening of the EASM in strong eruption years.The model simulation suggests that North and South China experience droughts and the Yangtze-Huaihe River Valley experiences floods during eruption years.In response to strong tropical volcanic eruptions,the meridional air temperature gradient in the upper troposphere is enhanced,which leads to a southward shift and an increase of the East Asian subtropical westerly jet stream （EASWJ）.At the same time,the land-sea thermal contrast between the Asian land mass and Northwest Pacific Ocean is weakened.The southward shift and increase of the EASWJ and reduction of the land-sea thermal contrast all contribute to a weakening of the EASM and EASM rainfall anomaly.展开更多
The Cenozoic volcanostratigraphy in the Changbaishan area had complex building processes.Twenty-two eruption periods have been determined from the Wangtian＇e, Touxi, and Changbaishan volcanoes. The complex volcanostr...The Cenozoic volcanostratigraphy in the Changbaishan area had complex building processes.Twenty-two eruption periods have been determined from the Wangtian＇e, Touxi, and Changbaishan volcanoes. The complex volcanostratigraphy of the Changbaishan area can be divided into four types of filling patterns from bottom to top. They are lava flows filling in valleys（LFFV）, lava flows filling in platform（LFFP）, lava flows formed the cone（LFFC）, and pyroclastic Flow filling in crater or valleys（PFFC/V）. LFFV has been divided into four layers and terminates as a lateral overlap. The topography of LFFV, which is controlled by the landform, is lens shaped with a wide flat top and narrow bottom.LFFP has been divided into three layers and terminates as a lateral downlap. The topography of LFFP is sheet and tabular shaped with a narrow top and wide bottom. It has large width to thickness ratio. It was built by multiple eruptive centers distributed along the fissure. The topography of LFFC, which is located above the LFFP, has a hummocky shape with a narrow sloping top and a wide flat bottom. It terminates as a later downlap or backstepping. It has large width to thickness ratio. It was built by a single eruptive center. The topography of PFFC/V, which located above the LFFC, LFFP, or valley, has the shape of fan and terminates as a lateral downlap or overlap. It has a small width to thickness ratio and was built by a single eruptive center. The filling pattern is controlled by temperature, SiO_2 content,volatile content, magma volume, and the paleolandform. In the short term, the eruptive production of the Changbaishan area is comenditic ash or pumice of a Plinian type eruption. The eruptive volume in future should be smaller than that of the Baguamiao period, and the filling pattern should be PFFC/V,which may cause huge damage to adjacent areas.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the Funds of the National Natural Science Foundation of China(NSFC),grant numbers 42174211,42230207,and U2039205.
文摘In this study,ionosonde observations over Fuke(19.5°N,109.1°E),Wuhan(30.5°N,114.4°E),and Mohe(53.5°N,122.3°E)were analyzed to demonstrate the responses of the sporadic E()to the severe atmospheric disturbances caused by the Tonga volcanic eruptions on January 15,2022.The most prominent signature was the disappearance of the layer after~10:00 UT over Wuhan and Fuke,which was attributed to the vertical drift caused by the eruptions.The occurred intermittently after 13:00 UT following the arrival of the tropospheric Lamb wave.To examine the causal mechanism for the intermittence,we also included data of horizontal winds in the mesosphere and lower thermosphere region recorded by the meteor radars at Wuhan and Mohe in this study.The wind disturbances with periods of~20 hours contributed to the formation of the layer in the nighttime on January 15.
文摘目的评估阿达木单抗联合激素治疗重症药疹的疗效和安全性。方法回顾性分析2023年1月至2024年2月于空军特色医学中心皮肤科住院治疗的16例重症药疹患者的临床资料,根据用药的不同将患者分为激素组(10例)和阿达木单抗联合激素治疗组(联合组)(6例)。比较2组药疹皮损面积和严重程度指数(drug eruption area and severity index,DASI)评分;比较2组患者疗效、住院时间、皮疹停止进展时间、激素减量时间、皮肤黏膜痒痛感缓解时间、激素初始剂量、激素最大剂量、皮疹停止进展时激素累积剂量及住院期间激素总剂量;比较2组患者血清铁蛋白、D-二聚体(D-dimer,D-D)、β2微球蛋白水平及不良反应发生情况。结果联合组治疗后DASI评分低于激素组(F=6.618,P=0.023)。联合组治疗后血清铁蛋白水平低于治疗前(P=0.002),激素组治疗后血清铁蛋白水平高于联合组(P=0.046);激素组治疗后D-D水平较治疗前下降(P<0.001);2组治疗前后β2微球蛋白水平差异具有统计学意义(Wald χ^(2)=11.066,P=0.001)。联合组皮疹停止进展时间、皮肤黏膜痒痛感缓解时间、激素减量时间、皮疹停止进展时激素的累积剂量及住院期间激素使用总剂量均低于激素组(t=2.221~3.733,P=0.002~0.043)。2组不良反应发生率差异均无统计学意义(P均>0.05)。结论阿达木单抗联合激素治疗可作为重症药疹的治疗选择,对于病情较重、病程较长和大剂量激素冲击治疗皮疹控制不佳的患者,二者联合使用,可以缩短重症药疹病程,减少激素用量。
基金The research was funded by the Natural Science Foundation of China(40172033)and the state volcano program of the tenth Five-Year Plan period(2001BA601B06-01-4).
文摘Since the eruption of the Tianchi volcano about 1000 years ago, there have been at least 3 to 5 eruptions of small to moderate size. In addition, hazardous avalanches, rock falls and debris flows have occurred during periods between eruptions. A future eruption of the Tianchi volcano is likely to involve explosive interaction between magma and the caldera lake. The volume of erupted magma is almost in a range of 0.1-0.5 km3. Tephra fallout may damage agriculture in a large area near the volcano. If only 1% of the lake water were ejected during an eruption and then precipitated over an area of 200 km2, the average rainfall would be 100 mm. Moreover, lahars are likely to occur as both tephra and water ejected from the caldera lake fall onto flanks of the volcano. Rocks avalanching into the caldera lake also would bring about grave hazards because seiches would be triggered and lake water with the volume equal to that of the landslide would spill out of the existing breach in the caldera and cause flooding downstream.
基金supported by the National Key Research and Development Project of China (Grant No. 2016YFA0600604)the National Natural Science Foundation of China (Grant No. 41461144001 and No. 41861144016)the Youth Innovation Promotion Association of the Chinese Academy of Sciences (Grant No. 2014064)
文摘With the gradual yet unequivocal phasing out of ozone depleting substances(ODSs), the environmental crisis caused by the discovery of an ozone hole over the Antarctic has lessened in severity and a promising recovery of the ozone layer is predicted in this century. However, strong volcanic activity can also cause ozone depletion that might be severe enough to threaten the existence of life on Earth. In this study, a transport model and a coupled chemistry–climate model were used to simulate the impacts of super volcanoes on ozone depletion. The volcanic eruptions in the experiments were the 1991 Mount Pinatubo eruption and a 100 × Pinatubo size eruption. The results show that the percentage of global mean total column ozone depletion in the 2050 RCP8.5 100 × Pinatubo scenario is approximately 6% compared to two years before the eruption and 6.4% in tropics. An identical simulation, 100 × Pinatubo eruption only with natural source ODSs, produces an ozone depletion of 2.5% compared to two years before the eruption, and with 4.4% loss in the tropics. Based on the model results,the reduced ODSs and stratospheric cooling lighten the ozone depletion after super volcanic eruption.
基金supported by the Strategic Priority Research Program(Grant No.XDA05110203) of the Chinese Academy of Sciencesthe Research Council of Norway through the India-Clim projectthe National Basic Research Program of China(Grant Nos.2012CB955401 and 2010CB951802)
文摘A 600-year integration performed with the Bergen Climate Model and National Centers for Environmental Prediction/National Center for Atmospheric Research （NCEP/NCAR） reanalysis data were used to investigate the impact of strong tropical volcanic eruptions on the East Asian summer monsoon （EASM） and EASM rainfall.Both the simulation and NCEP/NCAR reanalysis data show a weakening of the EASM in strong eruption years.The model simulation suggests that North and South China experience droughts and the Yangtze-Huaihe River Valley experiences floods during eruption years.In response to strong tropical volcanic eruptions,the meridional air temperature gradient in the upper troposphere is enhanced,which leads to a southward shift and an increase of the East Asian subtropical westerly jet stream （EASWJ）.At the same time,the land-sea thermal contrast between the Asian land mass and Northwest Pacific Ocean is weakened.The southward shift and increase of the EASWJ and reduction of the land-sea thermal contrast all contribute to a weakening of the EASM and EASM rainfall anomaly.
基金supported by the Natural Science Foundation of Jilin Province(20170101001JC)Natural Science Foundation of China(41472304)National Major Fundamental Research and Development Projects(2012CB822002)
文摘The Cenozoic volcanostratigraphy in the Changbaishan area had complex building processes.Twenty-two eruption periods have been determined from the Wangtian＇e, Touxi, and Changbaishan volcanoes. The complex volcanostratigraphy of the Changbaishan area can be divided into four types of filling patterns from bottom to top. They are lava flows filling in valleys（LFFV）, lava flows filling in platform（LFFP）, lava flows formed the cone（LFFC）, and pyroclastic Flow filling in crater or valleys（PFFC/V）. LFFV has been divided into four layers and terminates as a lateral overlap. The topography of LFFV, which is controlled by the landform, is lens shaped with a wide flat top and narrow bottom.LFFP has been divided into three layers and terminates as a lateral downlap. The topography of LFFP is sheet and tabular shaped with a narrow top and wide bottom. It has large width to thickness ratio. It was built by multiple eruptive centers distributed along the fissure. The topography of LFFC, which is located above the LFFP, has a hummocky shape with a narrow sloping top and a wide flat bottom. It terminates as a later downlap or backstepping. It has large width to thickness ratio. It was built by a single eruptive center. The topography of PFFC/V, which located above the LFFC, LFFP, or valley, has the shape of fan and terminates as a lateral downlap or overlap. It has a small width to thickness ratio and was built by a single eruptive center. The filling pattern is controlled by temperature, SiO_2 content,volatile content, magma volume, and the paleolandform. In the short term, the eruptive production of the Changbaishan area is comenditic ash or pumice of a Plinian type eruption. The eruptive volume in future should be smaller than that of the Baguamiao period, and the filling pattern should be PFFC/V,which may cause huge damage to adjacent areas.
