Xiazhuang uranium ore field,located in the southern part of the Nanling Metallogenic Belt,is considered one of the largest granite-related U regions in South China.In this paper,we contribute new apatite fission track...Xiazhuang uranium ore field,located in the southern part of the Nanling Metallogenic Belt,is considered one of the largest granite-related U regions in South China.In this paper,we contribute new apatite fission track data and thermal history modeling to constrain the exhumation history and evaluate preservation potential of the Xiazhuang Uranium ore field.Nine Triassic outcrop granite samples collected from different locations of Xiazhuang Uranium ore field yield AFT ages ranging from 43 to 24 Ma with similar mean confined fission track lengths ranging from 11.8±2.0 to 12.9±1.9μm and Dpar values between 1.01 and 1.51μm.The robustness time-temperature reconstructions of samples from the hanging wall of Huangpi fault show that the Xiazhuang Uranium ore field experienced a time of monotonous and slow cooling starting from middle Paleocene to middle Miocene(~60-10 Ma),followed by relatively rapid exhumation in the late Miocene(~10-5 Ma)and nearly thermal stability in the Pliocene-Quaternary(~5-0 Ma).The amount of exhumation after U mineralization since the Middle Paleogene was estimated as~4.3±1.8 km according to the integrated thermal history model.Previous studies indicate that the ore-forming ages of U deposits in the Xiazhuang ore field are mainly before Middle Paleocene and the mineralization depths are more than 4.4±1.2 km.Therefore,the exhumation history since middle Paleocene plays important roles in the preservation of the Xiazhuang Uranium ore field.展开更多
目的探讨单侧双通道脊柱内镜(UBE)治疗退行性腰椎疾病(DLD)术后疗效与影响因素关系。方法对2021年2月至2023年3月收治本科室的61例DLD患者进行回顾性分析,评价其术后疗效。随访时间12~38个月。男35个,女26个,年龄19~81岁,平均年龄54.4...目的探讨单侧双通道脊柱内镜(UBE)治疗退行性腰椎疾病(DLD)术后疗效与影响因素关系。方法对2021年2月至2023年3月收治本科室的61例DLD患者进行回顾性分析,评价其术后疗效。随访时间12~38个月。男35个,女26个,年龄19~81岁,平均年龄54.4岁。手术节段均为单节段,共61节段。记录患者围手术期及手术并发症情况;随访以末次随访为终止时间。采用疼痛视觉模拟评分(VAS)、Oswestry功能障碍指数(ODI)和改良MacNab标准评价临床疗效;手术前后行腰椎CT三维重建检查,观察并测量关节突关节切除内侧角(β角);椎间盘类型按照分类定位系统MSU(Michgan State University)基于MRI横断位分A、B、C区,依据区域定位法FSU(Functional Spine Unit)基于MRI或CT横断位、矢状位分级1~4级;统计采用配对t检验,及方差分析。结果61例患者均顺利完成手术。其中行腰椎间盘突出手术61例,其中合并中央管狭窄29例,合并侧隐窝狭窄54例。术中出现硬膜囊撕裂2例。术后出现短暂性下肢麻木3例,类脊髓综合征1例,感染1例。患者术后随访(12~38)个月。术后随访时,患者腿部VAS、ODI较术前明显下降(P值均<0.05)。术后末次随访时依据改良MacNab标准,优良率为65.6%(40/61)。腰椎三维CT影像学方面,测量β角均小于90°,平均值83.59°,范围(66.72°~89.32°)。基于MSU分区,A区37例,B区15例,C区9例;基于FSU位置分级,分别为1级1例,2级25例,3级2例,合并1和2级26例,2和3级4例,1和2、3级3例。方差分析显示术后满意度与椎间盘分区及分级、β角无关,与术后疼痛及功能障碍指数相关。结论单侧双通道脊柱内镜治疗退行性腰椎疾病术后疗效可能与术后β角及椎间盘分区、分级无关。分级、分区越复杂,手术难度越大,早期开展这项技术遇到的困难可能越多。展开更多
通过深沪湾高分辨率浅地层剖面声学地层和地质钻孔沉积地层的对比,并结合沉积物的粒度、微体古生物以及AMS14C测年的综合分析,揭示了研究区晚更新世末次冰期以来的地层层序,探讨了深沪湾的古环境演变。深沪湾高分辨率浅地层剖面自上而...通过深沪湾高分辨率浅地层剖面声学地层和地质钻孔沉积地层的对比,并结合沉积物的粒度、微体古生物以及AMS14C测年的综合分析,揭示了研究区晚更新世末次冰期以来的地层层序,探讨了深沪湾的古环境演变。深沪湾高分辨率浅地层剖面自上而下划分的5个声学地层单元与钻孔岩芯划分的5个沉积地层单元具有较好的对应关系。8.2 ka BP左右,全新世海侵使得海水进入深沪湾海域,海平面低于现今海平面10~12 m,气候凉爽;7 ka BP左右海水到达现今海平面位置,并于6 ka BP左右到达最高,约比现今海平面高2~3 m,气候温暖湿润,这一时期,近岸大量裸子植物被海水淹没并被沉积物快速掩埋;5 850~5 642 a BP研究区温度降低,该降温活动持续到2 ka BP左右,气候凉爽干燥;2 ka BP以来温度逐渐上升,600 a BP左右有一个相对冷期,之后温度又逐渐上升至现今水平。展开更多
基金the Foundation of State Key Laboratory of Nuclear Resources and Environment(Grant Nos.NRE2021-01,2022NRE34)the National Natural Science Foundation of China(Grant No.42162013)+1 种基金the Third Xinjiang Scientific Expedition Program(Grant No.2022xjkk1301)the Fund of National Key Laboratory of Science and Technology on Remote Sensing Information and imagery Analysis,Beijing Research Institute of Uranium Geology(Grant No.6142A01210405).
文摘Xiazhuang uranium ore field,located in the southern part of the Nanling Metallogenic Belt,is considered one of the largest granite-related U regions in South China.In this paper,we contribute new apatite fission track data and thermal history modeling to constrain the exhumation history and evaluate preservation potential of the Xiazhuang Uranium ore field.Nine Triassic outcrop granite samples collected from different locations of Xiazhuang Uranium ore field yield AFT ages ranging from 43 to 24 Ma with similar mean confined fission track lengths ranging from 11.8±2.0 to 12.9±1.9μm and Dpar values between 1.01 and 1.51μm.The robustness time-temperature reconstructions of samples from the hanging wall of Huangpi fault show that the Xiazhuang Uranium ore field experienced a time of monotonous and slow cooling starting from middle Paleocene to middle Miocene(~60-10 Ma),followed by relatively rapid exhumation in the late Miocene(~10-5 Ma)and nearly thermal stability in the Pliocene-Quaternary(~5-0 Ma).The amount of exhumation after U mineralization since the Middle Paleogene was estimated as~4.3±1.8 km according to the integrated thermal history model.Previous studies indicate that the ore-forming ages of U deposits in the Xiazhuang ore field are mainly before Middle Paleocene and the mineralization depths are more than 4.4±1.2 km.Therefore,the exhumation history since middle Paleocene plays important roles in the preservation of the Xiazhuang Uranium ore field.
文摘目的探讨单侧双通道脊柱内镜(UBE)治疗退行性腰椎疾病(DLD)术后疗效与影响因素关系。方法对2021年2月至2023年3月收治本科室的61例DLD患者进行回顾性分析,评价其术后疗效。随访时间12~38个月。男35个,女26个,年龄19~81岁,平均年龄54.4岁。手术节段均为单节段,共61节段。记录患者围手术期及手术并发症情况;随访以末次随访为终止时间。采用疼痛视觉模拟评分(VAS)、Oswestry功能障碍指数(ODI)和改良MacNab标准评价临床疗效;手术前后行腰椎CT三维重建检查,观察并测量关节突关节切除内侧角(β角);椎间盘类型按照分类定位系统MSU(Michgan State University)基于MRI横断位分A、B、C区,依据区域定位法FSU(Functional Spine Unit)基于MRI或CT横断位、矢状位分级1~4级;统计采用配对t检验,及方差分析。结果61例患者均顺利完成手术。其中行腰椎间盘突出手术61例,其中合并中央管狭窄29例,合并侧隐窝狭窄54例。术中出现硬膜囊撕裂2例。术后出现短暂性下肢麻木3例,类脊髓综合征1例,感染1例。患者术后随访(12~38)个月。术后随访时,患者腿部VAS、ODI较术前明显下降(P值均<0.05)。术后末次随访时依据改良MacNab标准,优良率为65.6%(40/61)。腰椎三维CT影像学方面,测量β角均小于90°,平均值83.59°,范围(66.72°~89.32°)。基于MSU分区,A区37例,B区15例,C区9例;基于FSU位置分级,分别为1级1例,2级25例,3级2例,合并1和2级26例,2和3级4例,1和2、3级3例。方差分析显示术后满意度与椎间盘分区及分级、β角无关,与术后疼痛及功能障碍指数相关。结论单侧双通道脊柱内镜治疗退行性腰椎疾病术后疗效可能与术后β角及椎间盘分区、分级无关。分级、分区越复杂,手术难度越大,早期开展这项技术遇到的困难可能越多。
文摘通过深沪湾高分辨率浅地层剖面声学地层和地质钻孔沉积地层的对比,并结合沉积物的粒度、微体古生物以及AMS14C测年的综合分析,揭示了研究区晚更新世末次冰期以来的地层层序,探讨了深沪湾的古环境演变。深沪湾高分辨率浅地层剖面自上而下划分的5个声学地层单元与钻孔岩芯划分的5个沉积地层单元具有较好的对应关系。8.2 ka BP左右,全新世海侵使得海水进入深沪湾海域,海平面低于现今海平面10~12 m,气候凉爽;7 ka BP左右海水到达现今海平面位置,并于6 ka BP左右到达最高,约比现今海平面高2~3 m,气候温暖湿润,这一时期,近岸大量裸子植物被海水淹没并被沉积物快速掩埋;5 850~5 642 a BP研究区温度降低,该降温活动持续到2 ka BP左右,气候凉爽干燥;2 ka BP以来温度逐渐上升,600 a BP左右有一个相对冷期,之后温度又逐渐上升至现今水平。
