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Layer-Valley Hall Effect under inversion and Time-Reversal Symmetries

Chinese Physics Letters 2024年第6期41卷 88-97页

作者：赵交交刘贵斌陈鹏姚裕贵张广宇杜罗军 Beijing National Laboratory for Condensed Matter Physics and Key Laboratory for Nanoscale Physics and DevicesInstitute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100190China Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Lab of Nanophotonics&Ultrafine Optoelectronic Systems School of PhysicsBeijing Institute of TechnologyBeijing 100081China Schoolof Microelectronics Southern University of Science and TechnologyShenzhen 518055China Songshan Lake Materials Laboratory Dongguan 523808China

Hall effects have been the central paradigms in modern physics,materials science and practical applications,and have led to many exciting breakthroughs,including the discovery of topological Chern invariants and the revolution of metrological resistance standard.To date,the Hall effects have mainly focused on a single degree of freedom(Do F),and most of them require the breaking of spatial-inversion and/or time-reversal symmetries.Here we demonstrate a new type of Hall effect,i.e.,layer-valley Hall effect,based on a combined layer-valley Do F characterized by the product of layer and valley indices.The layer-valley Hall effect has a quantum origin arising from the layer-valley contrasting Berry curvature,and can occur in nonmagnetic centrosymmetric crystals with both spatial-inversion and time-reversal symmetries,transcending the symmetry constraints of single Do F Hall effect based on the constituent layer or valley index.Moreover,the layer-valley Hall effect is highly tunable and shows a W-shaped pattern in response to the out-of-plane electric fields.Additionally,we discuss the potential detection approaches and material-specific design principles of layer-valley Hall effect.Our results demonstrate novel Hall physics and open up exotic paradigms for new research direction of layer-valleytronics that exploits the quantum nature of the coupled layer-valley DoF.

关键词： quantum inversion curvature

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A new approach for inversion of receiver function for crustal structure in the depth domain

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Earth and Planetary Physics 2022年第1期6卷 83-95页

作者： TianYu Zheng YuMei He Yue Zhu Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of Sciences(CAS)Beijing 100029China University of Chinese Academy of Sciences Beijing 100049China

A method for reconstructing crustal velocity structure using the optimization of stacking receiver function amplitude in the depth domain,named common conversion amplitude(CCA)inversion,is presented.The conversion amplitude in the depth domain,which represents the impedance change in the medium,is obtained by assigning the receiver function amplitude to the corresponding conversion position where the P-to-S conversion occurred.Utilizing the conversion amplitude variation with depth as an optimization objective,imposing reliable prior constraints on the structural model frame and velocity range,and adopting a stepwise search inversion technique,this method efficiently weakens the tendency of easily falling into the local extremum in conventional receiver function inversion.Synthetic tests show that the CCA inversion can reconstruct complex crustal velocity structures well and is especially suitable for revealing crustal evolution by estimating diverse velocity distributions.Its performance in reconstructing crustal structure is superior to that of the conventional receiver function imaging method.

关键词： crustal imaging receiver function depth domain inversion

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A two-step three dimensional marine magnetotelluric inversion method with considering rugged seafloor topography:Synthetic studies

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Science China Earth Sciences 2023年第4期66卷 765-780页

作者： Pengfei LIANG Qingyun DI Changmin FU Ruo WANG Qihui ZHEN Zhe YUN Jiagang ZHANG CAS Engineering Laboratory for Deep Resources Equipment and Technology Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Exploration Surveying Institute of Baogang Group Baotou 014010China

inversion of magnetotelluric(MT) responses has been used to explore the electrical conductivity distribution of the Earth’s interior. In three-dimensional(3-D) inversions, it is significant to use a good initial model, because final model obtained by most 3-D inversion methods is influenced by the initial model. Although uniform initial models are widely used in 3-D inversions, one-dimensional(1-D) initial models are alternatives, which could more appropriately represent the actual conductivity variations in the Earth’s interior. This study presents a two-step 3-D inversion method, especially for marine cases. This inversion method first concentrates on obtaining a 1-D initial model and then inverts for 3-D conductivity structures with it, in both of which the 3-D topography is carefully taken into consideration. This method was tested by synthetic models of different topography variations(depression-shaped, smoothly varying, channel-shaped and square-shaped plateau topography) and of heterogeneous layers with different checkerboard-type anomalies(sharp or smooth lateral conductivity variations) embedded in1-D model of depth-dependent conductivity. The comparisons were done about obtaining an initial model by the proposed method and that inverted from the corrected responses. The results of 3-D inversions by using the method of this study were also compared to that with different uniform initial models. Results of synthetic tests and comparisons were discussed by using directional information of newly introduced model-vector parameters. The performance and validity of this method was verified.It also revealed that some of the newly introduced model-vector parameters could be used to show the convergence of inversions and help to select inverse model.

关键词： Magnetotelluric Integral equation Topography inversion Convergence

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Analysis of inversion error characteristics of stellar occultation simulation data

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Earth and Planetary Physics 2022年第1期6卷 61-69页

作者： MingChen Sun QingLin Zhu Xiang Dong JiaJi Wu China Research Institute of Radiowave Propagation Qingdao 266107China Xidian University Xi’an 710126China

Atmospheric stellar occultation observation technology is an advanced space-based detection technology that can measure the vertical distribution of trace gas composition,temperature,and aerosol content in a planet’s atmosphere.In this study,an inversion algorithm of the onion-peeling method was constructed to invert the transmittance obtained from the forward mask.The method used a three-dimensional ray-tracing simulation to obtain the transmission path of the light in the Earth’s atmosphere.The relevant parameters were then combined in the high-resolution transmission molecular absorption(HITRAN)database,and line-by-line integration was performed to calculate the atmospheric transmittance.The transmittance value was then used as an input to calculate the vertical distribution of oxygen molecules when using the single-wavelength inversion of the onion-peeling method.Finally,the oxygen molecule content was compared with the value attained by the Mass Spectrometer and Incoherent Scatter Radar Extended(MSISE00)atmospheric model to determine the relative error of our model.The maximum error was found to be 0.3%,which is low enough to verify the reliability of our algorithm.Using Global-scale Observations of the Limb and Disk(GOLD)measured data to invert the oxygen number density,we calculated its relative deviation from the published result to further verify the algorithm.The inversion result was affected by factors such as prior data,the absorption spectral line type,the ellipticity of the Earth,and the accuracy of the orbit.Analysis of these error-influencing factors showed that the seasons and the Earth’s ellipticity affected the accuracy of the model only 0.001%and could therefore be ignored.However,latitude and solar activity had a greater impact on accuracy,on the order of 0.1%.The absorption line type affected the accuracy of the model by as much as 1%.All three of these factors therefore need to be considered during the inversion process.

关键词： stellar occultation onion-peeling GOLD inversion error

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Polymyxin resistance caused by large-scale genomic inversion due to IS26 intramolecular translocation in Klebsiella pneumoniae

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药学学报:英文版 2023年第9期13卷 3678-3693页

作者： Haibin Li Lang Sun Han Qiao Zongti Sun Penghe Wang Chunyang Xie Xinxin Hu Tongying Nie Xinyi Yang Guoqing Li Youwen Zhang Xiukun Wang Zhuorong Li Jiandong Jiang Congran Li Xuefu You Beijing Key Laboratory of Antimicrobial Agents Institute of Medicinal BiotechnologyChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100050China Institute of Medicinal Biotechnology Chinese Academy of Medical Science&Peking Union Medical CollegeBeijing 100050China State Key Laboratory of Bioactive Substance and Function of Natural Medicines Institute of Materia MedicaChinese Academy of Medical Science&Peking Union Medical CollegeBeijing 100050China

Polymyxin B and polymyxin E(colistin)are presently considered the last line of defense against human infections caused by multidrug-resistant Gram-negative organisms such as carbapenemase-producer Enterobacterales,Acinetobacter baumannii,and Klebsiella pneumoniae.Yet resistance to this last-line drugs is a major public health threat and is rapidly increasing.Polymyxin S2(S2)is a polymyxin B analogue previously synthesized in our institute with obviously high antibacterial activity and lower toxicity than polymyxin B and colistin.To predict the possible resistant mechanism of S2for wide clinical application,we experimentally induced bacterial resistant mutants and studied the preliminary resistance mechanisms.Mut-S,a resistant mutant of K.pneumoniae ATCC BAA-2146(Kpn2146)induced by S2,was analyzed by whole genome sequencing,transcriptomics,mass spectrometry and complementation experiment.Surprisingly,large-scale genomic inversion(LSGI)of approximately 1.1 Mbp in the chromosome caused by IS26mediated intramolecular transposition was found in Mut-S,which led to mgrB truncation,lipid A modification and hence S2resistance.The resistance can be complemented by plasmid carrying intact mgrB.The same mechanism was also found in polymyxin B and colistin induced drug-resistant mutants of Kpn2146(Mut-B and Mut-E,respectively).This is the first report of polymyxin resistance caused by IS26 intramolecular transposition mediated mgrB truncation in chromosome in K.pneumoniae.The findings broaden our scope of knowledge for polymyxin resistance and enriched our understanding of how bacteria can manage to survive in the presence of antibiotics.

关键词： Klebsiella pneumoniae Polymyxin resistance mgrB IS26 Whole genome sequencing Structural variation inversion

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Comprehensive Study of inversion Methods for Sound Speed Profiles in the South China Sea

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Journal of Ocean University of China 2022年第6期21卷 1487-1494页

作者： LI Jiemeihui SHI Yang YANG Yixin CHEN Cheng School of Marine Science and Technology Northwestern Polytechnical UniversityXi’an 710000China Shaanxi Key Laboratory of Underwater Information Technology Northwestern Polytechnical UniversityXi’an 710000China

Traditional acquisition method of sound speed profiles using hydro-acoustic instruments is accurate but time-consuming and costly.To overcome this problem,some inversion methods have been developed over the last few decades.In this study,a comprehensive comparison of two inversion methods–the acoustic inversion method(AIM)and the satellite observation reconstruction method(SOR)–is presented.For AIM,the sound speed profile is first parameterized by the empirical orthogonal function(EOF)and the optimal parameters are searched by simulated annealing algorithm with respect to the cross-correlation function of the receiving signal and the simulation signal.For SOR,remotely sensed data are used to construct sound speed profiles.An experiment was conducted in the northeast of the South China Sea to verify the two methods.Both methods can obtain sound speed profiles quickly and cheaply.Compared with the sound speed profiles obtained by a conductivity-temperature-depth(CTD)instrument,the root-meansquare-error(RMSE)of AIM is 0.55 m s^(−1) and that of SOR is 1.71 m s^(−1).It is clear that AIM provides better inversion performance than SOR.Another primary benefit of AIM is that this method has no limitation to the inversion depth.The simulation results of sound propagation in regard to the inversed sound speed profiles show that the transmission losses of AIM and CTD are consistent and that of SOR is adversely affected by the inversion error of the sound speed and the inversion depth.But SOR has particular advantages in the inversion coverage.Together,all of these advantages make the AIM particularly valuable in practice.

关键词： sound speed profile inversion EOF cross-correlation remote sensing South China Sea

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inversion for negative dislocation on elastic block boundaries in the northeastern margin of Qinghai-Xizang block and prediction for strong earthquake location

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Acta Seismologica Sinica(English Edition) 2005年第6期18卷 666-677页

作者：张希江在森王琪王双绪崔笃信张晓亮 Second Crust Monitoring and Application Center China Earthquake Administration Xi'an 710054 China Institute of Earthquake Science China Earthquake Administration Beijing 100036 China Institute of Seismology China Earthquake Administration Wuhan 430071 China

On the basis of the velocity field results of horizontal crustal movement obtained from GPS measurements during the periods of 1993-1999, 1999-2001 and 2001-2003 in the northeastern margin of Qinghai-Xizang block, and by the inversion of negative dislocation model for the elastic block boundaries, we provide in this paper a qualitative analysis and quantitative description for the difference of motion and deformation between the tectonic blocks and their boundary faults, time-space distribution of tectonic strain field, and locations with highly accumulated strain energy and correlative intensity. Furthermore, taking the regional tectonics and block strain into full consideration, we investigate the common features of background precursors relating to location prediction for M greater than or equal 6 earthquakes.

关键词： elastic block boundary negative dislocation model horizontal crustal movement inversion study of earthquake examples

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inversion of coseismic stress-triggered fault slips using borehole strainmeter observations

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Acta Seismologica Sinica(English Edition) 2006年第6期19卷 643-649页

作者：邱泽华阚宝祥唐磊张超凡宋茉 Institute of Crustal Dynamics China Earthquake AdministrationBeijing 100085 China Graduate University of the Chinese Academy of Sciences Beijing 100039 China

Coseismic stress-triggering is becoming a new hot spot of research. Coseismic strain steps recorded by borehole strainmeters are particularly valuable in studying coseismic stress-triggered fault slips. Based on the theory of dis location, one can invert the triggered fault slips with such data if he/she has a well understanding about the local faults. Genetic algorithm can be applied to significantly raise the efficiency of searching a best solution among all possibilities in this kind of inversion. A testifying check of the program and analyses of each parameter＇s influence may further enhance the reliability of inversion results. Taking complexity of geological structure into account, the inversion results should be regarded as the predominant property or a comprehensive effect of triggered local faults＇ activities. As an attempt, we inverted the assumingly active faults＇ slips triggered by the Ms=8.1 Kunlun Mountain earthquake over Beijing area.

关键词： coseismic strain step stress triggering inversion dislocation genetic algorithm （GA） the Kunlun Mountain earthquake

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inversion of UEP signatures induced by ships based on PSO method

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Defence Technology（防务技术） 2020年第1期16卷 172-177页

作者： Yu Peng Jin-fang Cheng Run-xiang Jiang Military Key Laboratory for Military Target Characteristics Naval University of EngineeringWuhan 430033PR China College of Weaponry Engineering Naval University of EngineeringWuhan 430033PR China

To model the underwater electric potential(UEP) of ships,a multiple point-electrodes method is commonly used.However,it is difficult to determine the total number of point-electrodes,their respective positions and current values.In this paper,the particle swarm optimization(PSO) method is applied to solve the number,positions and current values of these point-electrodes according to the UEP distribution at a known depth below the keel of a ship.A scaled ship model experiment is carried out to determine the effectiveness of the method.The results show that for hulls in a latural corrosion or cathodic protection state,the UEP inversion accuracy can reach 85% at different depths below the keel.This method is suitable for software implementation and can help the simulation and prediction of UEP signatures.

关键词： UEP PSO inversion Point-electrode

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Full waveform inversion based on the ensemble Kalman filter method using uniform sampling without replacement

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Science Bulletin 2019年第5期64卷 321-330页

作者： Jian Wang Dinghui Yang Hao Jing Hao Wu Department of Mathematical Sciences Tsinghua University

Full waveform inversion(FWI) has been increasingly more and more important in seismology to better understand the interior structure of the Earth. FWI, by taking advantage of both the traveltime and amplitude in the data, provides high-resolution model parameters of the earth which can produce images with high resolution. However, this inversion method conventionally suffers from non-uniqueness due to many local minima of the objective function and large computing costs. In this study, we propose a new FWI method in a semi-random framework by integrating the ensemble Kalman filter and uniform sampling without replacement. Numerical results demonstrate that the new method can achieve highresolution results and a wider convergence domain. Accordingly, the new method overcomes the disadvantage of conventional FWIs that depend strongly on the initial model.

关键词： Data assimilation Ensemble Kalman filter Uniform sampling without replacement Full waveform inversion

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