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Multisphere Tectonics of the Earth System

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Acta Geologica Sinica(English Edition) 2022年第3期96卷 727-741页

作者： REN Jishun niu baogui XU Qinqin ZHAO Lei LIU Jianhui LI Shan ZHU Junbin LIU Renyan Institute of Geology Chinese Academy of Geological SciencesBeijing 100037China

The fundamental theoretical framework of the Multisphere Tectonics of the Earth System is as follows:(1)It intends to extend the geotectonic studies from the crustal and lithospheric tectonics to the multisphere tectonics of the Ear th system as a whole.(2)The global dynamics driven by both the Earth system and the cosmic celestial system:solar energy,multispheric interactions of the Earth system and the combined effects of the motions of celestial bodies in the cosmos syste m are the driving forces of various geological processes.(3)The Continent-Ocean transformation theory:the continent and ocean are two opposite yet unified geological units,which can be transformed into each other;neither continent nor ocean wi ll survive forever;there is no one-way development of continental accretion or ocean extinction;the simple theory of one-way continental accretion is regarded as invalid.(4)The continental crust and mantle are characterized by multiple layers,with different layers liable to slide along the interfaces between them,but corroboration is needed that continents move as a who le or even drift freely.(5)The cyclic evolution theory:the development of Earth’s tectonics is not a uniform change,but a spiral forward evolution,characterized by a combination of non-uniform,non-linear,gradual and catastrophic changes;different evolutionary stages(tectonic cycles)of Earth have distinctive global tectonic patterns and characteristics,one tectonic mo del should not be applied to different tectonic cycles or evolutionary stages.(6)The structure and evolution of Earth are asymmetric and heterogeneous,thus one tectonic model cannot be applied to different areas of the world.(7)The polycyclic evolution of the continental crust:the continental crust is formed by polycyclic tectonics and magmatism,rather than simply lateral or vertical accretion.(8)The role of deep faults:the deep fault zones cutting through different layers of the crus t a nd mantle usually play important roles

关键词： deep fault global dynamics cyclic evolution theory Multisphere Tectonics Continent-Ocean transformation theory Earth system science

Geochronology of Yanshanian Magmatism and Metamorphism in the Hinterland of the Dabie Mountains and Their Geologic Implications

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Acta Geologica Sinica(English Edition) 1992年第2期66卷 155-163,222页

作者： Chen Tingyu niu baogui Liu Zhigang Fu Yunlian Ren Jishun Institute of Geology, Chinese Academy of Geological Sciences, Beijing Institute of Geology Chinese Academy of Geological Sciences Beijing

A strong tectono-magmatic thermal event has been revealed by field observations of granitic, migmatiticand metamorphic rocks in the hinterland of the Dabie Mountains. K-Ar, Ar-Ar and Rb-Sr determinationsshow that the event took place 133-117 Ma ago (Yanshanian). Contemporaneously, a southwestwardthrust-type ductile shearing at multiple levels occurred in the lower crust or at even deeper levels, suggestingthat the Dabie Mountains region was still under the influence ot strong continent-continent overlappingtectonism of the Yangtze block under the Sino-Korean block at depth. Metamorphic rocks of amphibolitefacies, migmatites and deep structural deformations resulting from this tectonothermal event are now exposedto the surface. The present features of the Dabie Mountains thus have appeared only since ca. 100 Ma B.P. Theblock composed of the Dabie Group is not an uplift or shield which would have undergone a long-continuederosion.

关键词： Geochronology of Yanshanian Magmatism and Metamorphism in the Hinterland of the Dabie Mountains and Their Geologic Implications

Microcontinents, Soft Collision and Polycyclic sutuing

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Continental Dynamics 1996年第1期 1-9页

作者： Ren Jishun niu baogui and Liu Zhigang (Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China)

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晚侏罗世承德盆地砾岩碎屑源区分析及构造意义

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岩石学报 2007年第3期23卷 655-666页

作者：和政军牛宝贵张新元中国地质科学院地质研究所北京100037 中国地质调查局地质发展中心北京100083

河北承德及寿王坟盆地在晚侏罗世土城子期堆积了大量的粗碎屑沉积。砾石成分统计结果显示,承德-寿王坟盆地充填的土城子组碎屑母岩组合主要有三种,其中火山岩、花岗质岩石和变质岩组合在承德盆地占绝时优势,反映了当时盆地以北的"内蒙地... 详细信息

河北承德及寿王坟盆地在晚侏罗世土城子期堆积了大量的粗碎屑沉积。砾石成分统计结果显示,承德-寿王坟盆地充填的土城子组碎屑母岩组合主要有三种,其中火山岩、花岗质岩石和变质岩组合在承德盆地占绝时优势,反映了当时盆地以北的"内蒙地轴"为主要的蚀源区。向北逆冲的双庙断裂将承德盆地分成南北两个部分,断裂两侧的砾石成分组合基本相同,显示出碎屑物质共同来源于北部,同时也暗示了该断裂在土城子期可能没有强烈的活动(强烈活动期可能在土城子组之后?)。分析表明,承德盆地南部的不对称向斜构造两侧砾石成分截然不同,说明该向斜构造控制了碎屑分布,是同沉积期形成的。该盆地南侧的碎屑供应量远远小于北侧,反映了控制盆地南缘发育的向北逆冲的灰窑断层可能是一条次要的同沉积断裂。在晚侏罗世整体向南推进的逆冲断裂系统中,灰窑断裂和双庙断裂应属于背向逆冲断层。承德盆地中大量的粗碎屑堆积与同期冲断带的耦合关系分析,指示了这一时期盆地北侧存在强烈的逆冲断裂活动。作为主要物源区,北部的"内蒙地轴"在晚侏罗世发生了强烈的隆升-剥蚀作用,推测当时在地貌上可能存在近E—W走向的古山系(或古高原?)。

关键词：承德盆地晚侏罗世砾岩碎屑物源区分析

陕南山阳地区刘岭群砂岩岩石地球化学特征及其构造背景分析

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地质科学 2005年第4期40卷 594-607页

作者：和政军牛宝贵任纪舜中国地质科学院地质研究所北京100037

陕南山阳地区中晚泥盆世刘岭群位于秦岭造山带的商丹断裂带与山阳断裂之间。由于所处的特殊位置,刘岭群沉积特点及其盆地形成时期构造背景的确定,可以为秦岭地区古生代以来构造演化提供有价值的信息。岩石地球化学分析表明,刘岭群砂岩... 详细信息

陕南山阳地区中晚泥盆世刘岭群位于秦岭造山带的商丹断裂带与山阳断裂之间。由于所处的特殊位置,刘岭群沉积特点及其盆地形成时期构造背景的确定,可以为秦岭地区古生代以来构造演化提供有价值的信息。岩石地球化学分析表明,刘岭群砂岩主要氧化物特征以SiO2和K2O含量较高为特点,具有较高的化学成熟度,反映出其碎屑物质可能来源于相对稳定的大陆源区或更老的沉积岩再旋回的沉积产物。砂岩的稀土元素LREE/HREE比值为3.61,属轻稀土中等富集;Eu/Eu值为0.77,属亏损型,与后太古代大陆地壳沉积岩总体演化特点相一致。主量元素氧化物、稀土元素及微量元素的多种图解和多种参数交叉分析,表明刘岭群沉积不具备前陆盆地堆积的特征。根据砂岩岩石地球化学的构造背景判别和物源区判别,结合沉积序列和沉积岩石学等分析,指示中晚泥盆世刘岭群碎屑岩应属于被动大陆边缘盆地沉积。

关键词：刘岭群被动大陆边缘砂岩岩石地球化学中-晚泥盆世秦岭造山带陕南山阳地区

Design and Verification of Parallel Hip Exoskeleton Considering Output Torque Anisotropy

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Journal of Bionic Engineering 2024年第3期21卷 1305-1320页

作者： Jilong Xu Yunzhan niu Fucai Liu Engineering Research Center of the Ministry of Education for Intelligent Control System and Intelligent Equipment Yanshan UniversityQinhuangdao066004China Key Laboratory of Industrial Computer Control Engineering of Heibei Province Yanshan UniversityQinhuangdao066004China College of Mechanical Engineering Yanshan UniversityQinhuangdao066004China

In rehabilitation training,it is crucial to consider the compatibility between exoskeletons and human legs in ***,most exoskeletons today adopt an anthropomorphic serial structure,which results in rotational centers that are not precisely aligned with the center of the hip *** address this issue,we introduce a novel exoskeleton called the Parallel Hip Exoskeleton(PH-Exo)in this ***-Exo is meticulously designed based on the anisotropic law of output *** the friction of the drive components,a dynamic model of the human-machine complex is *** analysis demonstrates that PH-Exo not only exhibits outstanding torque performance but also achieves high controllability in both flexion/extension and adduction/abduction ***,a robust controller is designed to address model uncertainty,friction,and external *** experiments indicate that under the control of the robust controller,each motor achieves excellent tracking performance.

关键词： Hip exoskeleton Parallel mechanism Misalignment Anisotropy Output torque

An Asynchronous Variational Integrator for Contact Problems Involving Elastoplastic Solids

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Acta Mechanica Solida Sinica 2024年第2期37卷 305-315页

作者： Zongwu niu Zixiao Wang Yongxing Shen University of Michigan-Shanghai Jiao Tong University Joint Institute Shanghai Jiao Tong UniversityShanghai200240China School of Agriculture and Biology Shanghai Jiao Tong UniversityShanghai200240China Department of Biostatistics Johns Hopkins Bloomberg School of Public HealthBaltimoreMaryland21205USA

Simulations of contact problems involving at least one plastic solid may be costly due to their strong nonlinearity and requirements of *** this work,we develop an explicit asynchronous variational integrator(AVI)for inelastic non-frictional contact problems involving a plastic *** AVI assigns each element in the mesh an independent time step and updates the solution at the elements and nodes *** asynchrony makes the AVI highly efficient in solving such bi-material *** advantage of the AVI,the constitutive update is locally performed in one element at a time,and contact constraints are also enforced on only one *** time step of the contact element is subdivided into multiple segments,and the fields are updated *** a contact event,only one element involving a few degrees of freedom is considered,leading to high *** proposed formulation is first verified with a pure elastodynamics benchmark and further applied to a contact problem involving an elastoplastic solid with non-associative volumetric *** numerical results indicate that the AVI exhibits excellent energy behaviors and has high computational efficiency.

关键词： Asynchronous variational integrator Plasticity Contact Computational efficiency Finite element method

Vascularization ability of glioma stem cells in different three-dimensional microenvironments

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Regenerative Biomaterials 2024年第1期3卷 34-43页

作者： Xuanzhi Wang Tao Xu Chaoshi niu Department of Neurosurgery The First Affliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230036China Department of Neurosurgery Sichuan Provincial People's HospitalUniversity of Electronic Science and Technology of ChinaChengdu 610072People's Republic of China Center for Bio-intelligent Manufacturing and Living Matter Bioprinting Research Institute of Tsinghua University in ShenzhenTsinghua UniversityShenzhen 518057People's Republicof China

Glioblastoma(GBM)is among the most common and aggressive adult central nervous system *** prominent charac-teristic of GBM is the presence of abnormal microvessels.A significant correlation between angiogenesis and prognosis has been *** reconstructing this neovascula-rization and tumor microenvironment through personalized in vitro disease models presents a significant ***,it is crucial to develop new anti-angiogenic therapies for *** this study,3D bioprinted glioma stem cell(GSC)-laden hydrogel scaffolds,hybrid Gsc hydrogels and ceil-free hydrogel scaffolds were manufactured to investigate the vas-cularization ability of GsCs in varying 3D microenvironments.

关键词： 3D bioprinting xenograft tumors GSC-laden hydrogel scaffold glioblastoma angiogenesis

An integrative mathematical model of microwave ion thruster for mHz-frequency thrust noise analysis

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Chinese Journal of Aeronautics 2024年第4期37卷 121-136页

作者： Xiang niu Hui LIU Daren YU Plasma Propulsion Laboratory Harbin Institute of TechnologyHarbin 150001China

Many high-precision space missions need thrusters to produce thrust with low noise to compensate for disturbances and ensure satellite platform stability. Microwave ion thruster is characterized with a wide thrust range and potential for these missions. A cost-effective and accurate mathematical model is crucial for mHz-frequency thrust noise analysis and feedback controller design. The Particle-In-Cell(PIC) and global models are two common simulation tools. The PIC model is characterized with high accuracy but huge computation cost, which is difficult to analyze long-time performance characteristics. Now, the global model is only used for the discharge chamber with low accuracy and cannot reflect ion extraction properties. In this paper, an integrative mathematical model is built for a 1-cm microwave ion thruster and can reflect ion beamlet divergence and impingement on the Accelerator Grid(AG). Simulation results show good agreement with experiments at 0.06 sccm. However, the model demonstrates worse consistency with experiments when the flux increases to 0.1 sccm, which may be because the influence of neutral gas on the Electron Cyclotron Resonance(ECR) is not considered in the model. A long-time(1000 s) simulation is conducted with this model under 35 μN. It takes 3 hrs, and the thrust noise reaches 1 μN/Hz^(0.5) at 1 mHz.

关键词： Electric propulsion Microwave ion thruster Integrative model Sheath property Ion beamlet divergence Thrust noise Plasma