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Mesozoic uplift of the Dabashan and Micangshan-Hannan Dome in the South Qinling orogenic belt

Science China Earth Sciences 2022年第3期65卷 426-436页

作者： yongdong li Xiong XIONG Yashan FENG School of Geophysics and Geomatics University of GeosciencesWuhan 430074China

The topographic evolution of continental orogens is important for understanding continental orogenic processes,geodynamic mechanisms,and climatic and environmental *** Qinling Orogen is a major orogenic belt in China,and its uplift history can provide insights into the tectonic configuration and geodynamics of China and East *** studies have shown that the Dabashan and Micangshan-Hannan Dome(MHD)in the South Qinling orogenic belt were uplifted during the ***,the magnitude of the uplift remains *** this study,using sedimentary records in the northern Sichuan Basin and lithospheric flexural modeling,we estimated the magnitude of Mesozoic uplift of the Dabashan and MHD,along with the effective elastic thickness(Te)of the Sichuan *** Dabashan and MHD were uplifted by approximately 1220 and 880 m during the Middle Jurassic and Early Cretaceous,***,we propose that the present-day elevation of the Dabashan and MHD is primarily the result of Mesozoic *** differences in the duration and amount of uplift between different tectonic units indicate that the uplift processes and driving mechanisms in the South Qinling orogenic belt were different in the Mesozoic and *** uplift was the result of convergence of the North China and South China blocks advanced from east to west,whereas Cenozoic uplift was driven by ongoing indentation of the Indian Plate into Eurasia from southwest to *** lithospheric strength of the northern Sichuan Basin was weakened from the Middle Jurassic to Early Cretaceous,and Tedecreased from 73 to 57 *** may have been caused by the flexure-related bending stresses in the lithosphere that developed due to the large topographic loading.

关键词： South Qinling orogenic belt Dabashan Micangshan-Hannan Dome Mesozoic Uplift

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Dynamic mechanisms controlling the topography of Longmenshan area

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Science China Earth Sciences 2020年第1期63卷 121-131页

作者： Yuan XIE yongdong li Xiong XIONG Hubei Subsurface Multi-Scale Imaging Key Laboratory Institute of Geophysics and GeomaticsChina University of Geosciences

The Longmenshan fault, which defines the eastern edge of the Tibetan Plateau, is one of the steepest margins of the plateau with a sharp elevation drop of about 4 km over a distance less than 100 km across the Longmenshan fault. The mechanism which is responsible for controlling and maintaining the elevation difference is highly debated. Using multiple observations including seismic velocity model, Moho depth, effective elastic thickness of the lithosphere, we conducted a quantitative study for elucidating the contributions from crust and lithospheric mantle by an integrated analysis of lithospheric isostasy and flexure. It is shown that the topography of the Longmenshan fault is supported by both lithospheric isostasy and flexure statically, and lower crustal channel flow and mantle convection dynamically. Different mechanisms have different weights for contribution to the topography of the Songpan-Ganzi block and the Sichuan Basin. The static and dynamic support contribute roughly the same to the topographic difference of ~4 km between the two sides of the Longmenshan fault. The static topographic difference of ~2 km is mainly resulted from the lithospheric isostasy, while the dynamic one of ~2 km is contributed by the uprising of the accumulated material in the lower crust beneath the Songpan-Ganzi block and the downward drag force caused by the upper mantle convection under the Sichuan Basin. It is thus suggested that the lower crustal flow and upper mantle convection are dynamic forces which should be taken into account in the studies on the dynamics in the Longmenshan and surrounding regions.

关键词： Topography Longmenshan fault zone lithospheric isostasy lithospheric flexure Dynamic topography

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Review of Three-phase Soft Switching Inverters and Challenges for Motor Drives

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CES Transactions on Electrical Machines and Systems 2024年第2期8卷 177-190页

作者： Haifeng Lu Qiao Wang Jianyun Chai yongdong li IEEE the Department of Electrical Engineering Tsinghua UniversityBeijing 100084China the School of Electrical Engineering Xinjiang UniversityUrumqi 830047China

For electric vehicles (EVs),it is necessary to improve endurance mileage by improving the *** exists a trend towards increasing the system voltage and switching frequency,contributing to improve charging speed and power ***,this trend poses significant challenges for high-voltage and high-frequency motor controllers,which are plagued by increased switching losses and pronounced switching oscillations as consequences of hard *** deployment of soft switching technology presents a viable solution to mitigate these *** paper reviews the applications of soft switching technologies for three-phase inverters and classifies them based on distinct *** each type of inverter,the advantages and disadvantages are ***,the paper introduces the research progress and control methods of soft switching inverters (SSIs).Moreover,it presents a comparative analysis among the conventional hard switching inverters (HSIs),an active clamping resonant DC link inverter (ACRDCli) and an auxiliary resonant commuted pole inverter (ARCPI).Finally,the problems and prospects of soft switching technology applied to motor controllers for EVs are put forward.

关键词： Soft switching inverters Zero-voltage switching Electric vehicles Motor drives

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Vector valley Hall edge solitons in the photonic lattice with type-Ⅱ Dirac cones

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Frontiers of physics 2022年第5期17卷 75-82页

作者： Yiqing Tian Yiqi Zhang yongdong li Milivoj RBelić Key Laboratory for Physical Electronics and Devices of the Ministry of Education&Shaanxi Key Lab of Information Photonic Technique School of Electronic and Information EngineeringXi’an Jiaotong UniversityXi’an 710049China Science Program Texas A&M University at QatarP.O.Box 23874 DohaQatar

Topological edge solitons represent a significant research topic in the nonlinear topological *** maintain their profiles during propagation,due to the joint action of lattice potential and nonlinearity,and at the same time are immune to defects or disorders,thanks to the topological *** the past few years topological edge solitons were reported in systems composed of helical waveguide arrays,in which the time-reversal symmetry is effectively *** recently,topological valley Hall edge solitons have been demonstrated in straight waveguide arrays with the time-reversal symmetry ***,these were scalar solitary ***,for the first time,we report vector valley Hall edge solitons in straight waveguide arrays arranged according to the photonic lattice with innate type-II Dirac cones,which is different from the traditional photonic lattices with type-I Dirac cones such as honeycomb *** comes about because the valley Hall edge state can possess both negative and positive dispersions,which allows the mixing of two different edge states into a vector *** results not only provide a novel avenue for manipulating topological edge states in the nonlinear regime,but also enlighten relevant research based on the lattices with type-II Dirac cones.

关键词： valley Hall effect topological edge soliton photonic topological insulator

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The “liberation” Theme of Modern Chinese literature

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Social Sciences in China 2022年第1期43卷 21-36页

作者： li yongdong 邵亚楠 School of literature Southwestern University the School of Foreign Languages at Tianjin Chengjian University

The concept of “liberation” has profoundly influenced the development of modern Chinese literature,giving rise to a “liberation” theme with profound *** Chinese literature can be analyzed from the joint perspectives of the liberators,the routes to liberation and the scope of *** among the liberators have led to the two different concepts of self-liberation and being liberated;the differences in the routes to liberation have led to the intermixture of liberation based on persuasion and struggle-based liberation;and the difference in the scope of liberation derives from the alternation of the partial achievement of thoroughgoing liberation and the full realization of incremental *** Chinese concept of liberation was strongly shaped by the Communist Party of China (CPC);compared to the work of those writers influenced by the CPC’s concept of “liberation,” the writings of ordinary non-Communist writers present “liberation” *** latter tend to adopt an either/or attitude toward liberation,whereas the former ensure that liberation theme reflects the interaction and blending of different types of “liberation” concepts,thus establishing a new form of “liberation” *** mark the centenary of the CPC,we have reviewed and explored the “liberation” theme of modern Chinese literature in the hope that we will gain a full understanding of the theoretical discourse and historical practice of “liberation,” taking a dialectical approach to freedom and responsibility,respecting tradition while boldly pursuing innovation,and striving to explore the realistic significance and ideological value of literary works.

关键词： modern Chinese literature “liberation”theme Communist Party of China concept of liberation

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Microwave frequency downshift in the time-varying collision plasma

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Plasma Science and Technology 2020年第2期22卷 73-78页

作者： Kun CHEN Chao CHANG yongdong li Hongguang WANG Chunliang liU Key Laboratory for Physical Electronics and Devices of the Ministry of Education Xi'an Jiaotong UniversityXi’an 710049People’s Republic of China School of Electronic Science and Engineering Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Microwave frequency downshift in the time-varying collision plasma has been demonstrated by particle-in-cell *** simulation results are consistent with the theoretical analysis,and the preconditions for microwave frequency downshift are that the collision frequency needs to be greater than the incident wave frequency,and the plasma frequency is two times greater than the incident wave ***,the simulation results are compared with the reported experimental results indicating good agreement.

关键词： frequency downshift time-varying collision plasma particle-in-cell(PIC)simulation

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Modulation and Voltage Balancing Control of Dual Five-level ANPC Inverter for Ship Electric Propulsion Systems

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Chinese Journal of Electrical Engineering 2021年第4期7卷 78-92页

作者： Xiaohui Xu Xingchi Song Kui Wang Nianzhou liu Wenfeng Long Zedong Zheng yongdong li Science and Technology on Ship Integrated Power System Technology Laboratory Wuhan Institute of Marine Electric PropulsionWuhan 430070China China State Key Laboratory of Power System Tsinghua UniversityBeijing 100084China

Open-end winding motors are used extensively in ship electric propulsion systems,in which medium-voltage high-power inverters are a critical *** increase the system voltage and power density,a dual five-level active neutral-point clamped(ANPC)inverter is proposed herein to drive medium-voltage open-end winding motors for ship electric *** phase of this inverter comprises two five-level ANPC bridges and all the phases are powered by a common direct-current link.A hybrid modulation method is proposed to control this *** series-connected switches in all the five-level ANPC bridges are operated at the fundamental frequency,and the other switches are controlled with a phase-shifted pulse-width modulation(PWM),which can achieve a natural balance between the neutral-point voltage and flying capacitor voltages in a carrier period.A closed-loop capacitor voltage balancing method based on adjusting the duty ratios of the PWM signals is *** neutral-point voltage and flying capacitor voltages can be controlled independently and balanced without affecting the output phase *** and experimental results are presented to demonstrate the validity of this method.

关键词： Multilevel inverter active neutral-point clamped(ANPC) capacitor voltage balance open-end winding motor drive

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Analysis of microwave propagation in a time-varying plasma slab with particle-in-cell simulations

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Plasma Science and Technology 2019年第10期21卷 47-53页

作者： Kun CHEN Chao CHANG yongdong li Hongguang WANG Chunliang liU Key Laboratory for Physical Electronics and Devices of the Ministry of Education Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China School of Electronic Science and Engineering Xi’an Jiaotong UniversityXi’an 710049People’s Republic of China

Continuous microwave propagation through a time-varying plasma and frequency up-conversion has been demonstrated by particle-in-cell (PIC) simulation. In principle, it is possible to transform a 2.45 GHz source radiation to an arbitrary larger frequency radiation. The energy conversion is also obtained by the theoretical analysis and has been testified by PIC simulation. The source wave was propagating in a parallel plate waveguide locally filled with the ionized gas. In this paper we would discuss the effects of the rise time, the plasma length, the switching time and the collision frequency on the energy conversion, and the methods to improve the upshift wave energy are proposed. We also put forward the new concept of the critical values of the rise time and the source wave amplitude to provide a theoretical basis for the selection of parameters in the experiments.

关键词： continuous microwave time-varying plasma frequency up-conversion particle-incell (PIC) simulation

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Modes decomposition in particle-in-cell software CEMPIC

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Chinese Physics B 2020年第10期29卷 143-147页

作者： Aiping Fang Shanshan liang yongdong li Hongguang Wang Yue Wang School of Physics Xi'an Jiaotong UniversityXi'an 710049China State Key Laboratory of Intense Pulsed Radiation Simulation and Effect(Northwest Institute of Nuclear Technology) Xi'an 710024China Key Laboratory for Physical Electronics and Devices of the Ministry of Education School of Electronic and Information EngineeringXi'an Jiaotong UniversityXi'an 710049China Xian Moduo Technology Co. LtdXi'an 710049China

The numerical method of modes analysis and decomposition of the output signal in 3D electromagnetic particle-in-cell simulation is presented. By the method, multiple modes can be resolved at one time using a set of diagnostic data, the amplitudes and the phases of the specified modes can all be given separately. Based on the method, the output signals of one X-band tri-bend mode converter used for one high power microwave device, with ionization process in the device due to the strong normal electric field, are analyzed and decomposed.

关键词： particle-in-cell mode decomposition tri-bend mode converter high power microwave device

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Development of RPA-Cas12a-fluorescence assay for rapid and reliable detection of human bocavirus 1

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Animal Models and Experimental Medicine 2024年第2期7卷 179-188页

作者： Weidong Qian Xuefei Wang Ting Wang Jie Huang Qian Zhang yongdong li Si Chen School of Food and Biological Engineering Shaanxi University of Science and TechnologyXi'anP.R.China Department of Dermatology Huazhong University of Science and Technology Union Shenzhen HospitalShenzhenP.R.China Ningbo Municipal Center for Disease Control and Prevention NingboP.R.China Medical College of Shenzhen University ShenzhenP.R.China

Human bocavirus(HBoV)1 is considered an important pathogen that mainly affects infants aged 6–24 months,but preventing viral transmission in resource-limited regions through rapid and affordable on-site diagnosis of individuals with early infection of HBoV1 remains somewhat ***,we present a novel faster,lower cost,reliable method for the detection of HBoV1,which integrates a recombinase polymerase amplification(RPA)assay with the CRISPR/Cas12a system,designated the RPA-Cas12a-fluorescence *** RPA-Cas12a-fluorescence system can specifically detect target gene levels as low as 0.5 copies of HBoV1 plasmid DNA per microliter within 40 min at 37℃without the need for sophisticated *** method also demonstrates excellent specificity without cross-reactivity to non-target ***,the method was appraised using 28 clinical samples,and displayed high accuracy with positive and negative predictive agreement of 90.9%and 100%,***,our proposed rapid and sensitive HBoV1 detection method,the RPA-Cas12a-fluorescence assay,shows promising potential for early on-site diagnosis of HBoV1 infection in the fields of public health and health *** established RPA-Cas12a-fluorescence assay is rapid and reliable method for human bocavirus 1 *** RPA-Cas12a-fluorescence assay can be completed within 40 min with robust specificity and sensitivity of 0.5 copies/μl.

关键词： CRISPR-Cas12a detection human bocavirus 1 on-site diagnosis recombinase polymerase amplification

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