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The anomalous Response of Elastoplatic Circular Plates Under Impulsive Loading

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上海交通大学学报 2004年第Z2期38卷 14-18页

作者： Wu guiying Liu wei Yang guitong Institute of Applied Mechanics Taiyuan University of Technology Taiyuan030024 China Institute of Applied Mechanics Taiyuan University of Technology Taiyuan030024 China Institute of Applied Mechanics Taiyuan University of Technology Taiyuan030024 China

The anomalous nonlinear elastic, perfectly plastic response behaviors of circular plate subjected to short transverse pulse load is studied. The plate is assumed fixed-pin along the boundary. 'anomalous' here means that the final deflection may be in the direction opposite that of the load. It has been found by detailed numerical analyses that there exists anomalous response in some narrow loading ranges, so called slots. By further calculations it is shown that this special dynamic behavior is related to coupling affects of internal forces and large plastic deformation after removal loading. Further plastic dissipation will be lead to anomalous dynamic response. This phenomena could be considered as the coupling of the geometry nonlinearity, material nonlinearity,elastic effects and the irrecoverable of the plastic deformation.

关键词： anomalous response elastoplastic plates numerical analyses

Multi-scale regionalization based mining of spatio-temporal teleconnection patterns between anomalous sea and land climate events

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Journal of Central South University 2017年第10期24卷 2438-2448页

作者：徐枫石岩邓敏龚健雅刘启亮金瑞 Department of Geo-informatics Central South UniversityChangsha 410083China State Key Laboratory of Information Engineering in Surveying(Mapping&Remote Sensing Wuhan University)Wuhan 430079China Collaborative Innovation Center of Geospatial Technology Wuhan UniversityWuhan 430079China

Climate sequences can be applied to defining sensitive climate zones, and then the mining of spatio-temporal teleconnection patterns is useful for learning from the past and preparing for the future. However, scale-dependency in this kind of pattern is still not well handled by existing work. Therefore, in this study, the multi-scale regionalization is embedded into the spatio-temporal teleconnection pattern mining between anomalous sea and land climatic events. A modified scale-space clustering algorithm is first developed to group climate sequences into multi-scale climate zones. Then, scale variance analysis method is employed to identify climate zones at characteristic scales, indicating the main characteristics of geographical phenomena. Finally, by using the climate zones identified at characteristic scales, a time association rule mining algorithm based on sliding time windows is employed to discover spatio-temporal teleconnection patterns. Experiments on sea surface temperature, sea level pressure, land precipitation and land temperature datasets show that many patterns obtained by the multi-scale approach are coincident with prior knowledge, indicating that this method is effective and reasonable. In addition, some unknown teleconnection patterns discovered from the multi-scale approach can be further used to guide the prediction of land climate.

关键词： climate sequences anomalous climatic events spatio-temporal teleconnection patterns multi-scale regionalization

anomalous Lattice Expansion of Bi-based Superconductors

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Science China Mathematics 1993年第9期36卷 1123-1128页

作者：曹国辉李阳王耘波马如璋赵忠贤程本培孔捷 Department of Materials Physics University of Science and Technology of BeijingBeijing 100083PRC Institute of Physics Academia SinicaBeijing 100080PRC Research Institute of Solid State Physics Academia SinicaHefei 230031PRC

The dependence of X-ray diffraction on temperature was measured to studythe properties of thermal expansion and distortion of lattices in the Bi-system superconduc-tors.Results show that the anomalous expansion of lattices in the Bi-based superconductingphases 2223 and 2212 exists both in the high and low temperature regions.In the high tem-perature region（230～200K）,the anomalous expansion occurs at the same temperature forboth the 2223 and 2212 phases.But in the low temperature region,the two phases havedifferent anomalous temperatures（Ta）;however,they still obey the relation Ta=Tco+～20K.The present result,along with the observation of M（o|¨）ssbauer spectroscopy and internalfriction,shows that the structural instability related with the softening and anomalous ex-pansion of lattices occurs as a precursor effect to the onset of superconductivity.

关键词： Bi-system superconductors anomalous lattice expansion X-ray diffraction

Leaky cavity modes in metasurfaces:a route to low-loss wideband anomalous dispersion

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Photonics Research 2023年第6期11卷 1085-1093页

作者： XIAOFENG WANG JIAFU WANG YAJUAN HAN MINGBAO YAN YONGFENG LI TONGHAO LIU HUA MA SHAOBO QU Shaanxi Key Laboratory of Artificially-Structured Functional Material and Devices Air Force Engineering UniversityXi’an 710051China

Metasurfaces have provided unprecedented degrees of freedom in manipulating electromagnetic waves upon interfaces.In this work,we first explore the condition of wide operating bandwidth in the view of reflective scheme,which indicates the necessity of anomalous dispersion.To this end,the leaky cavity modes(LCMs)in the metaatom are analyzed and can make effective permittivity inversely proportional to frequency.Here we employ the longitudinal Fabry-Perot(F-P)resonances and transverse plasmonic resonances to improve the LCMs efficiency.It is shown that the order of F-P resonance can be customized by the plasmonic modes,that is,the F-P cavity propagation phase should match the phase delay of surface currents excited on the meta-atom.The nth order F-P resonance will multiply the permittivity by a factor of n,allowing larger phase accumulation with increasing frequencies and forming nonlinear phase distribution which can be applied in weak chromatic-aberration focusing design.As a proof-of-concept,we demonstrate a planar weak chromatic-aberration focusing reflector with a thickness ofλ_(0)∕9 at 16.0-21.0 GHz.This work paves a robust way to advanced functional materials with anomalous dispersion and can be extended to higher frequencies such as terahertz,infrared,and optical frequencies.

关键词： cavity anomalous dispersion

High resolution imaging with anomalous saturated excitation

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Photonics Research 2021年第1期9卷 21-26页

作者： BO DU XIANG-DONG CHEN ZE-HAO WANG SHAO-CHUN ZHANG EN-HUI WANG GUANG-CAN GUO FANG-WEN SUN CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

The nonlinear fluorescence emission has been widely applied for high spatial resolution optical imaging.Here,we studied the fluorescence anomalous saturating effect of the nitrogen vacancy defect in diamond.The fluorescence reduction was observed with high power laser excitation.It increased the nonlinearity of the fluorescence emission,and changed the spatial frequency distribution of the fluorescence image.We used a differential excitation protocol to extract the high spatial frequency information.By modulating the excitation laser’s power,the spatial resolution of imaging was improved approximately 1.6 times in comparison with the confocal microscopy.Due to the simplicity of the experimental setup and data processing,we expect this method can be used for improving the spatial resolution of sensing and biological labeling with the defects in solids.

关键词： excitation resolution anomalous

Quantum anomalous Hall effect in two-dimensional magnetic insulator heterojunctions

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npj Computational Materials 2020年第1期6卷 405-412页

作者： Jinbo Pan Jiabin Yu Yan-Fang Zhang Shixuan Du Anderson Janotti Chao-Xing Liu Qimin Yan Department of Physics Temple UniversityPhiladelphiaPA 19122USA Department of Physics The Pennsylvania State UniversityUniversity ParkPA 16802USA Condensed Matter Theory Center Department of PhysicsUniversity of MarylandCollege ParkMaryland 20742USA Institute of Physics Chinese Academy of ScienceBeijing 100190China Department of Materials Science and Engineering University of DelawareDE 19716 WilmingtonUSA

Recent years have witnessed tremendous success in the discovery of topological states of matter.Particularly,sophisticated theoretical methods in time-reversal-invariant topological phases have been developed,leading to the comprehensive search of crystal database and the prediction of thousands of topological materials.In contrast,the discovery of magnetic topological phases that break time reversal is still limited to several exemplary materials because the coexistence of magnetism and topological electronic band structure is rare in a single compound.To overcome this challenge,we propose an alternative approach to realize the quantum anomalous Hall(QAH)effect,a typical example of magnetic topological phase,via engineering two-dimensional(2D)magnetic van der Waals heterojunctions.

关键词： magnetic anomalous effect

Numerical Study for the Role Playing of Atmospheric Dynamic Processes Caused by Seasonal and Non-seasonal Forcings in Formation of the Short-Term anomalous Climate Change

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Science China Chemistry 1993年第5期36卷 599-609页

作者：倪允琪王万秋袁重光张勤 Department of Atmospheric Sciences Naniing University Nanjing 210008 PRC Institute of Atmospheric Physics Academia Sinica Beijing 100029 PRC Department of Meteorology Institute of Nanjing Meteorology Nanjing 210009 PRC

In this paper, it has been pointed out that anomalous climate change can be found, which is similar to that caused by anomalous external forcing, in the 25-year simulations from the model without non-seasonal external forcings. It shows that the short-term anomalous climate change can be formed by dynamic processes in the atmosphere caused by seasonal and non-seasonal external forcings.In this research, two numerical experiments with different initial states and different time sub-series of the natural climate change have been done using the IAP atmospheric general circulation model with same sea surface temperature anomalies in the tropical Pacific. The results reveal that anomalous climate phenomena in the atmosphere can arise as a result of interaction between the inherent internal dynamic process (caused by seasonal external forcings) in the long-range climate natural change process of the atmosphere and the dynamic process caused by non-seasonal external forcings (external dynamic process); in

关键词： dynamic process interaction anomalous climate change.

A Possible Reason About Origin of Singularity and anomalous Dispersion in Peridynamics

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Computer Modeling in Engineering & Sciences 2019年第11期121卷 385-398页

作者： Xinfeng Wang Zaixing Huang State Key Laboratory of Mechanics and Control of Mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

In the benchmark problems of peridynamics,there are some eccentric results,for example,singularity of uniaxial tension and anomalous dispersion of wave.The reasons to give rise to these results are investigated.We calculated local tension and wave of an infinite rod after adding a divergence of local stress in the peridynamic motion equation.The acquired results verify that the singularity in the peridynamic solution of local tension problem and anomalous dispersion of peridynamic wave are all eliminated.Therefore,the anomalous features of some peridynamic solutions likely stem from the lack of local stress characterizing contact interactions.

关键词： Peridynamics singularity of displacement anomalous dispersion peridynamic wave

Transfer of information in an anomalous dispersion medium

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Science China(Physics,Mechanics & Astronomy) 2003年第4期46卷 428-436页

作者：黄超光张元仲 Institute of High Energy Physics Chinese Academy of SciencesBeijing 100039China Institute of Theoretical Physics Chinese Academy of SciencesBeijing 100080China

The transfer of information and signal velocity in an anomalous dispersion medium are studied. We propose that the discontinuous points in the envelop and its derivatives of any order are the information carried by a pulse different from others. The signal velocity will not exceed the speed of the shift of these discontinuous points. We study the propagation of pulses with a triangle envelop and with the envelop made up by three pieces of quadratic curve in dilute, anomalous dispersion gas with double gain lines. The discontinuous points of the envelop, its first derivative, and its second derivative are shown to propagate with vacuum speed of light c in the medium. A criterion has been suggested to determine theoretically whether the distortion of a pulse can be ignored.

关键词： light propagation, anomalous dispersion medium, signal velocity