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Subduction tectonics vs.plume tectonics——Discussion on driving forces for plate motion 被引量:13
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作者 Ling CHEN Xu WANG +2 位作者 Xiaofeng LIANG Bo WAN Lijun LIU 《Science China Earth Sciences》 SCIE EI CAS CSCD 2020年第3期315-328,共14页
Plate tectonics describes the horizontal motions of lithospheric plates,the Earths outer shell,and interactions among them across the Earths surface.Since the establishment of the theory of plate tectonics about half ... Plate tectonics describes the horizontal motions of lithospheric plates,the Earths outer shell,and interactions among them across the Earths surface.Since the establishment of the theory of plate tectonics about half a century ago,considerable debates have remained regarding the driving forces for plate motion.The early"Bottom up"view,i.e.,the convecting mantledriven mechanism,states that mantle plumes originating from the core-mantle boundary act at the base of plates,accelerating continental breakup and driving plate motion.Toward the present,however,the"Top down"idea is more widely accepted,according to which the negative buoyancy of oceanic plates is the dominant driving force for plate motion,and the subducting slabs control surface tectonics and mantle convection.In this regard,plate tectonics is also known as subduction tectonics."Top down"tectonics has received wide supports from numerous geological and geophysical observations.On the other hand,recent studies indicate that the acceleration/deceleration of individual plates over the million-year timescale may reflect the effects of mantle plumes.It is also suggested that surface uplift and subsidence within stable cratonic areas are correlated with plumerelated magmatic activities over the hundred-million-year timescale.On the global scale,the cyclical supercontinent assembly and breakup seem to be coupled with superplume activities during the past two billion years.These correlations over various spatial and temporal scales indicate the close relationship and intensive interactions between plate tectonics and plume tectonics throughout the history of the Earth and the considerable influence of plumes on plate motion.Indeed,we can acquire a comprehensive understanding of the driving forces for plate motion and operation mechanism of the Earth's dynamic system only through joint analyses and integrated studies on plate tectonics and plume tectonics. 展开更多
关键词 driving forces for plate motion negative buoyancy of plates Subduction tectonics Plume tectonics
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A Dynamic Coupling of Ocean and Plate Motion
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作者 Yongfeng Yang 《International Journal of Geosciences》 CAS 2024年第9期737-763,共27页
Plate motion representing a remarkable Earth process is widely attributed to several primary forces such as ridge push and slab pull. Recently, we have presented that the ocean water pressure against the wall of conti... Plate motion representing a remarkable Earth process is widely attributed to several primary forces such as ridge push and slab pull. Recently, we have presented that the ocean water pressure against the wall of continents may generate enormous force on continents. Continents are physically fixed on the top of the lithosphere that has been already broken into individual plates, this attachment enables the force to be laterally transferred to the lithospheric plates. In this study, we combine the force and the existing plate driving forces (i.e., ridge push, slab pull, collisional, and shearing) to account for plate motion. We show that the modelled movements for the South American, African, North American, Eurasian, Australian, Pacific plates are well agreement with the observed movements in both speed and azimuth, with a Root Mean Square Error (RMSE) of the modelled speed against the observed speed of 0.91, 3.76, 2.77, 2.31, 7.43, and 1.95 mm/yr, respectively. 展开更多
关键词 Ocean Water Pressure force Ocean-Continent Interaction plate driving force Lithospheric plate plate motion
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负浮力是板块运动的驱动力吗?关于岩石断裂力学的讨论 被引量:1
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作者 周辉 邱亮 颜丹平 《地学前缘》 EI CAS CSCD 北大核心 2020年第1期270-274,共5页
本文从岩石断裂力学的角度,讨论了俯冲板块下拉牵引力(负浮力)作为板块运动初始驱动力的可能性。笔者总结已发表的岩石抗张强度的岩石力学实验结果,并和现在普遍认为的负浮力的数量级进行对比分析,结果表明大洋岩石圈上部岩石强度较低,... 本文从岩石断裂力学的角度,讨论了俯冲板块下拉牵引力(负浮力)作为板块运动初始驱动力的可能性。笔者总结已发表的岩石抗张强度的岩石力学实验结果,并和现在普遍认为的负浮力的数量级进行对比分析,结果表明大洋岩石圈上部岩石强度较低,仅有n×10 MPa。虽然随着温度和压力的增加岩石圈的强度不断增强,但是在板块俯冲的初始阶段,大洋岩石圈可能无法承受拖曳板块运动高达n×10^2 MPa的应力。此外,构造模拟、热开裂、疲劳断裂、俯冲挠曲、俯冲脱水以及熔融作用等地质现象的分析,也表明俯冲板块的负浮力作为板块运动初始驱动力是不符合客观事实的。 展开更多
关键词 岩石断裂力学 板块运动驱动力 负浮力 岩石圈强度
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新型Cu-IPMC的制备与性能测试及在软体驱动方面的应用 被引量:1
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作者 杨静 田爱芬 +2 位作者 张东升 张富强 李泽州 《功能材料》 EI CAS CSCD 北大核心 2019年第6期6019-6022,共4页
面向正在到来的无人化时代,很多学者采用离子聚合物-金属复合材料(IPMC)作为软体驱动材料来研究软体机器人。目前的IPMC基本都采用铂电极,但铂电极比较昂贵,因此,探索采用价格便宜的铜来制备新型IPMC。首先通过化学镀的方法制备了铜型... 面向正在到来的无人化时代,很多学者采用离子聚合物-金属复合材料(IPMC)作为软体驱动材料来研究软体机器人。目前的IPMC基本都采用铂电极,但铂电极比较昂贵,因此,探索采用价格便宜的铜来制备新型IPMC。首先通过化学镀的方法制备了铜型离子聚合物-金属复合材料(Cu-IPMC),并对其位移、力输出进行性能测试。结果表明,Cu-IPMC的耐受电压可达到10V,远超Pt-IPMC;力输出也较传统Pt-IPMC有所提升,最大可达到17mN;位移最大为30mm。通过研究为Cu-IPMC替代传统Pt-IPMC在软体驱动方面的应用提供了依据。 展开更多
关键词 Cu-IPMC 化学镀 运动性能 力输出 软体驱动
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基于相位调谐的旋转摆盘发动机驱动机构运动与受力分析
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作者 魏振航 王世宇 夏春花 《机械工程学报》 EI CAS CSCD 北大核心 2024年第3期109-119,共11页
旋转摆盘发动机具有结构紧凑和比功率大等优点,广泛应用于潜航器和鱼雷等军事装备中。利用坐标变换矩阵求得了摆盘轨迹、活塞位移和连杆摆角的解析表达式,揭示了斜轴夹角和摆盘半径等结构参数对摆盘运动和连杆摆角的影响规律。考虑活塞... 旋转摆盘发动机具有结构紧凑和比功率大等优点,广泛应用于潜航器和鱼雷等军事装备中。利用坐标变换矩阵求得了摆盘轨迹、活塞位移和连杆摆角的解析表达式,揭示了斜轴夹角和摆盘半径等结构参数对摆盘运动和连杆摆角的影响规律。考虑活塞分布的空间对称性以及燃气压力变化的时间对称性,利用相位调谐原理分析了摆盘的受力特征,揭示了燃气压力谐波阶次和活塞个数对摆盘受力的影响规律。研究结果表明,摆盘边缘的运动轨迹呈球面“8”字形;由于连杆的空间摆动,活塞位移并非连杆大头位移沿活塞轴向的分量;通过调整活塞个数与燃气压力谐波阶次之间的组合关系,可平衡摆盘上的力或力矩。 展开更多
关键词 摆盘发动机 驱动机构 运动规律 受力分析 相位调谐
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