2023年12月18日甘肃积石山发生M_(S)6.2地震,该地震造成了严重的地质灾害,属国内近些年来6级以上地震所罕见.基于多阶段定位方法对2023年积石山M_(S)6.2地震序列进行了重定位,根据gCAP(generalized Cut And Paste)方法反演了序列中M_(S)...2023年12月18日甘肃积石山发生M_(S)6.2地震,该地震造成了严重的地质灾害,属国内近些年来6级以上地震所罕见.基于多阶段定位方法对2023年积石山M_(S)6.2地震序列进行了重定位,根据gCAP(generalized Cut And Paste)方法反演了序列中M_(S)≥3.0以上地震的震源机制及矩心深度,并对震源机制节面进行聚类分析,获取了地震序列的主要断层面形状,计算了积石山地震序列震源区的构造应力场,研究了其应力场与震源机制节面及断层面的关系,最后结合地质构造、地壳形变等资料综合探讨和推测了积石山地震序列可能的发震构造.结果显示:(1)重定位结果表明,积石山M_(S)6.2地震序列震中区的长轴主要沿着拉脊山北缘断裂南段呈NNW向的优势展布,整个序列长约15km、宽约6km,北端、南端各分别止于大河家镇南侧及积石山县西侧,且存在显著的丛集分区特征,主要划分为大河家镇到刘集乡之间的北段余震稀疏区,以及刘集乡到积石山县西侧之间的南段余震密集区,其中南段余震密集区呈现为NW-SE向的分支和NNW-SSE向的分支,且两个分支形成了NW端分叉且SE端汇聚的分布特征,大部分余震主要集中在NW-SE向分支而积石山M_(S)6.2主震位于NNW-SSE向分支的NE侧.整个序列的平均震源深度约为11.4km,大多数地震主要集中在9~14km深度范围,其中主震的初始破裂深度为13.6km.震源深度剖面清晰勾勒出地震序列的主要发震断层面倾向为NE向,积石山M_(S)6.2主震则位于倾向NE的断层面底端,余震基本位于M_(S)6.2主震的上方,大体呈现为单侧破裂的特征.(2)gCAP波形反演表明,积石山M_(S)6.2主震震源机制节面I的走向/倾角/滑动角为304°/55°/65°,节面II的走向/倾角/滑动角为163°/42°/121°,P轴方位51°和其倾伏角7°,矩心深度10km,矩震级M_(W)5.95.主震及M_(S)3.0以上余震的震源机制主要表现以逆冲为主且略带少量的走滑分量,震源机制的P轴主要呈现近NE-SW向的水平挤压,矩心深度介于9~12km之间,平均矩心深度10.7km.(3)震源机制节面聚类分析得出两簇聚类中心节面,其中NE倾向的聚类中心节面走向311°及倾角43°,其形状和重定位的深度剖面大体一致.震源区应力场反演结果显示,积石山震源区的最优压应力轴走向、倾伏角分别为57°和15°,表明积石山震源区应力场表现为NE向的近水平挤压,并以逆冲为主的应力状态.通过将其反演得到的应力场投影到积石山地震序列震源机制节面及其聚类中心节面,发现积石山应力体系在这些震源机制节面和聚类中心节面上均更容易产生逆冲破裂的地震事件.(4)结合已有区域地质构造、地壳形变等研究,综合分析认为积石山M_(S)6.2地震序列的发震构造和拉脊山北缘主断裂南段(积石山东缘断裂)与其至少两条走向略不同的反冲断层组成的“y”型冲断构造所在的复杂逆冲推覆环境有关,其中积石山M_(S)6.2主震位于NNW-SSE走向、SW倾向拉脊山北缘主断裂南段与其NW-SE走向、NNW-SSE走向及NE倾向的次级反冲断层形成的背冲式构造“y”形汇合部位,并在拉脊山北缘主断裂南段上的反冲断层上发生了相对密集的积石山余震序列.展开更多
Based on the biological prototype characteristics of shark’s gill jet orifice,the flexible driving characteristics of ionic exchange polymer metal composites(IPMC)artificial muscle materials and the use of sleeve fle...Based on the biological prototype characteristics of shark’s gill jet orifice,the flexible driving characteristics of ionic exchange polymer metal composites(IPMC)artificial muscle materials and the use of sleeve flexible connector,the IPMC linear driving unit simulation model is built and the IPMC material-driving dynamic control structure of bionic gill unit is developed.Meanwhile,through the stress analysis of bionic gill plate and the motion simulation of bionic gill unit,it is verified that various dynamic control and active control of the jet orifice under the condition of different mainstream field velocities will be taken by using IPMC material-driving.Moreover,the large-deflection deformation of bionic gill plate under dynamic pressure and the comparative analysis with that of a rigid gill plate is studied,leading to the achievement of approximate revised modifier from real value to theoretical value of the displacement control of IPMC.展开更多
Large-scale gypsum rocks associated with world-class Pb-Zn ore formations are widely distributed in the Lanping Basin,Sowthwest China.Geochemical studies alongside field investigations were conducted in this study to ...Large-scale gypsum rocks associated with world-class Pb-Zn ore formations are widely distributed in the Lanping Basin,Sowthwest China.Geochemical studies alongside field investigations were conducted in this study to determine the source and evolutionary processes of the gypsum rocks in this area.The gypsum sequences in the Lanping Basin developed in two formations:the Triassic Sanhedong Formation and the Paleogene Yunlong Formation.The gypsum hosted in the former displays a primary thick-banded structure withδ34SV-CDT values in the range of 14.5‰−14.8‰.Combined with the 87Sr/86Sr values(0.707737−0.707783)of limestone,it can be suggested that the Sanhedong Formation is of marine origin.In contrast,the gypsum from the Paleogene Yunlong Formation is characterized by the dome,bead and diapiric salt structures,wider range of both 87Sr/86Sr(0.707695−0.708629)andδ34SV-CDT values(9.6‰−17‰),thus indicating a marine source but with the input of continental materials.The initial layered salt formations were formed by chemical deposition in a basin and were later intensely deformed by collisional orogeny during the Himalaya period.As a result,variable salt structures were formed.We hereby propose an evolutionary model to elucidate the genesis of the gypsum formations in the Lanping Basin.展开更多
This paper used the modern evaluation method of DEA （Data Envelopment Analysis） to assess the comparative efficiency and then on the basis of this among multiple schemes chose the optimal scheme of agricultural prod...This paper used the modern evaluation method of DEA （Data Envelopment Analysis） to assess the comparative efficiency and then on the basis of this among multiple schemes chose the optimal scheme of agricultural production structure adjustment. Based on the results of DEA model, we dissected scale advantages of each discretionary scheme or plan. We examined scale advantages of each discretionary scheme, tested profoundly a definitive purpose behind not-DEA efficient, which elucidated the system and methodology to enhance these discretionary plans. At the end, another method had been proposed to rank and select the optimal scheme. The research was important to guide the practice if the modification of agricultural production industrial structure was carded on.展开更多
文摘2023年12月18日甘肃积石山发生M_(S)6.2地震,该地震造成了严重的地质灾害,属国内近些年来6级以上地震所罕见.基于多阶段定位方法对2023年积石山M_(S)6.2地震序列进行了重定位,根据gCAP(generalized Cut And Paste)方法反演了序列中M_(S)≥3.0以上地震的震源机制及矩心深度,并对震源机制节面进行聚类分析,获取了地震序列的主要断层面形状,计算了积石山地震序列震源区的构造应力场,研究了其应力场与震源机制节面及断层面的关系,最后结合地质构造、地壳形变等资料综合探讨和推测了积石山地震序列可能的发震构造.结果显示:(1)重定位结果表明,积石山M_(S)6.2地震序列震中区的长轴主要沿着拉脊山北缘断裂南段呈NNW向的优势展布,整个序列长约15km、宽约6km,北端、南端各分别止于大河家镇南侧及积石山县西侧,且存在显著的丛集分区特征,主要划分为大河家镇到刘集乡之间的北段余震稀疏区,以及刘集乡到积石山县西侧之间的南段余震密集区,其中南段余震密集区呈现为NW-SE向的分支和NNW-SSE向的分支,且两个分支形成了NW端分叉且SE端汇聚的分布特征,大部分余震主要集中在NW-SE向分支而积石山M_(S)6.2主震位于NNW-SSE向分支的NE侧.整个序列的平均震源深度约为11.4km,大多数地震主要集中在9~14km深度范围,其中主震的初始破裂深度为13.6km.震源深度剖面清晰勾勒出地震序列的主要发震断层面倾向为NE向,积石山M_(S)6.2主震则位于倾向NE的断层面底端,余震基本位于M_(S)6.2主震的上方,大体呈现为单侧破裂的特征.(2)gCAP波形反演表明,积石山M_(S)6.2主震震源机制节面I的走向/倾角/滑动角为304°/55°/65°,节面II的走向/倾角/滑动角为163°/42°/121°,P轴方位51°和其倾伏角7°,矩心深度10km,矩震级M_(W)5.95.主震及M_(S)3.0以上余震的震源机制主要表现以逆冲为主且略带少量的走滑分量,震源机制的P轴主要呈现近NE-SW向的水平挤压,矩心深度介于9~12km之间,平均矩心深度10.7km.(3)震源机制节面聚类分析得出两簇聚类中心节面,其中NE倾向的聚类中心节面走向311°及倾角43°,其形状和重定位的深度剖面大体一致.震源区应力场反演结果显示,积石山震源区的最优压应力轴走向、倾伏角分别为57°和15°,表明积石山震源区应力场表现为NE向的近水平挤压,并以逆冲为主的应力状态.通过将其反演得到的应力场投影到积石山地震序列震源机制节面及其聚类中心节面,发现积石山应力体系在这些震源机制节面和聚类中心节面上均更容易产生逆冲破裂的地震事件.(4)结合已有区域地质构造、地壳形变等研究,综合分析认为积石山M_(S)6.2地震序列的发震构造和拉脊山北缘主断裂南段(积石山东缘断裂)与其至少两条走向略不同的反冲断层组成的“y”型冲断构造所在的复杂逆冲推覆环境有关,其中积石山M_(S)6.2主震位于NNW-SSE走向、SW倾向拉脊山北缘主断裂南段与其NW-SE走向、NNW-SSE走向及NE倾向的次级反冲断层形成的背冲式构造“y”形汇合部位,并在拉脊山北缘主断裂南段上的反冲断层上发生了相对密集的积石山余震序列.
基金Project(51275102)supported by the National Natural Science Foundation of ChinaProject(HEUCF140713)supported by the Fundamental Research Funds for the Central Universities,China
文摘Based on the biological prototype characteristics of shark’s gill jet orifice,the flexible driving characteristics of ionic exchange polymer metal composites(IPMC)artificial muscle materials and the use of sleeve flexible connector,the IPMC linear driving unit simulation model is built and the IPMC material-driving dynamic control structure of bionic gill unit is developed.Meanwhile,through the stress analysis of bionic gill plate and the motion simulation of bionic gill unit,it is verified that various dynamic control and active control of the jet orifice under the condition of different mainstream field velocities will be taken by using IPMC material-driving.Moreover,the large-deflection deformation of bionic gill plate under dynamic pressure and the comparative analysis with that of a rigid gill plate is studied,leading to the achievement of approximate revised modifier from real value to theoretical value of the displacement control of IPMC.
基金Project(41362008)supported by the National Natural Science Foundation of China。
文摘Large-scale gypsum rocks associated with world-class Pb-Zn ore formations are widely distributed in the Lanping Basin,Sowthwest China.Geochemical studies alongside field investigations were conducted in this study to determine the source and evolutionary processes of the gypsum rocks in this area.The gypsum sequences in the Lanping Basin developed in two formations:the Triassic Sanhedong Formation and the Paleogene Yunlong Formation.The gypsum hosted in the former displays a primary thick-banded structure withδ34SV-CDT values in the range of 14.5‰−14.8‰.Combined with the 87Sr/86Sr values(0.707737−0.707783)of limestone,it can be suggested that the Sanhedong Formation is of marine origin.In contrast,the gypsum from the Paleogene Yunlong Formation is characterized by the dome,bead and diapiric salt structures,wider range of both 87Sr/86Sr(0.707695−0.708629)andδ34SV-CDT values(9.6‰−17‰),thus indicating a marine source but with the input of continental materials.The initial layered salt formations were formed by chemical deposition in a basin and were later intensely deformed by collisional orogeny during the Himalaya period.As a result,variable salt structures were formed.We hereby propose an evolutionary model to elucidate the genesis of the gypsum formations in the Lanping Basin.
文摘This paper used the modern evaluation method of DEA （Data Envelopment Analysis） to assess the comparative efficiency and then on the basis of this among multiple schemes chose the optimal scheme of agricultural production structure adjustment. Based on the results of DEA model, we dissected scale advantages of each discretionary scheme or plan. We examined scale advantages of each discretionary scheme, tested profoundly a definitive purpose behind not-DEA efficient, which elucidated the system and methodology to enhance these discretionary plans. At the end, another method had been proposed to rank and select the optimal scheme. The research was important to guide the practice if the modification of agricultural production industrial structure was carded on.
