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Observation of topological charge transformations in acoustic vortex using passive periodic systems

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 140-147页

作者： Di-Chao Chen Xie Liu Changqing Xu Da-jian Wu Ying Cheng Xiao-jun Liu School of Physics and Technology Nanjing Normal University Key Laboratory of Modern Acoustics School of Physics Nanjing University

Vortex transmutation utilizes a periodic system, which not only enables the alteration of the topological charge(TC) of unstable input vortices but also facilitates their transformation into stable structures. This approach is crucial for investigating the characteristics of vortices in various wave systems. Here, we achieve acoustic vortex TC transmutation by employing a welldesigned dual-structured plate external system(DPES). The interactions between the acoustic vortex and the finite-order discrete rotational symmetry lead to the transformation of its topological charge when complete rotational symmetry is broken to Nthorder discrete symmetry. Our results experimentally demonstrate the acoustic vortex TC transmutation based on passive artificial structures, enabling numerous applications in particle manipulation and information multiplexing as well as advancing our understanding and control over free-space acoustic vortices.

关键词： acoustic vortex topological charge transformation artificial structure

Extra-narrowband metallic filters with an ultrathin single-layer metallic grating

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Chinese Physics B 2020年第6期29卷 242-248页

作者： ran Wang Qi-Huang Gong jian-jun Chen State Key Laboratory for Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Microelectronics Instruments and Equipments R&D Center Institude of Microelectronics of Chinese Academy of SciencesBeijing 100029China Nano-optoelectronics Frontier Center of Ministry of Education(NFC-MOE)&Collaborative Innovation Center of Quantum Matter Peking UniversityBeijing 100871China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Narrowband and high-transmission optical filters are extensively used in color display technology, optical information processing, and high-sensitive sensing. Because of large ohmic losses in metallic nanostructures, metallic filters usually exhibit low transmittances and broad bandwidths. By employing both strong field enhancements in metallic nano-slits and the Wood’s anomaly in a periodic metallic grating, an extra-narrowband and high-transmission metallic filter is numerically predicted in an ultrathin single-layer metallic grating. Simulation results show that the Wood’s anomaly in the ultrathin(thickness H = 60 nm) single-layer metallic grating results in large field enhancements in the substrate and low losses in the metallic grating. As a result, the transmission bandwidth(transmittance T > 60%) at λ = 1200 nm is as small as △λFWHM=1.6 nm, which is smaller than 4% of that in the previous thin dielectric and metallic filters. The corresponding quality factor is as high as Q = λ/△λFWHM= 750, which is 40 times greater than that in the previous reports. Moreover, the thickness of our metallic filter(H = 60 nm) is smaller than 40% of that in the previous reports, and its maximum transmittance can reach up to 80%. In experiments, a narrowband metallic filter with a bandwidth of about △λFWHM = 10 nm, which is smaller than 25% of that in the previous metallic filters, is demonstrated.

关键词： metallic filter extra-narrowband field enhancement Wood’s anomaly

Infrared Radiance Simulation and Application under Cloudy Sky Conditions Based on HIRTM

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Journal of Electronic Science and Technology 2019年第2期17卷 161-170页

作者： jian-Hua Qu jun-Jie Yan Mao-Nong ran Huayun Shinetek Company China Meteorological Administration

An algorithm based on hyperspectral infrared cloudy radiative transfer model (HIRTM) is introduced and a simulation method for infrared image of the generation geostationary meteorological satellite is proposed. Based on the parameters from weather research and forecast (WRF), such as the water content, atmospheric temperature, and humidity profile, the simulation data for the advanced Himawari imager (AHI) infrared radiative (IR) channels of Himawari-8 are obtained. Simulated results based on HIRTM agree well with the observed data. Further, the movement, development, and change of the cloud are well predicated. And the simulation of IR cloud image for the weather forecast has been obtained. This paper provides an improved method for evaluation and improvement of regional numerical model for weather forecast.

关键词： Hyperspectral infrared cloudy radiative transfer model (HIRTM) regional numerical model satellite cloud image

Identification of a dual functional betulinic acid analog for the treatment of osteoarthritis by phenotypic screening

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Science China Life Sciences 2025年第1期 300-302页

作者： Ze-Min Lin Mai Xiang Wen-Hui Wei Shu-Hui Fan Li Chen Jie Wang Xiao-Qian Yang Chun-Hao Yang Shi-jun He jian-Ping Zuo Laboratory of Immunopharmacology State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of Sciences School of Pharmacy University of Chinese Academy of Sciences School of Pharmacy Nanjing University of Chinese Medicine State Key Laboratory of Drug Research Department of Medicinal ChemistryShanghai Institute of Materia MedicaChinese Academy of Sciences Innovation Research Institute of Traditional Chinese Medicine Shanghai University of Traditional Chinese Medicine Experiment Center for Science and Technology Shanghai University of Traditional Chinese Medicine

Dear Editor, Phenotypic drug discovery, which observes compound effects on physiology,has given way to targeting specific molecules, but has revived by using modern methods to find drugs based on therapeutic outcomes in disease models(Vincent et al., 2022). Osteoarthritis(OA) is a prevalent chronic joint disorder, primarily affecting knee joints, with osteoclast activation due to low-grade inflammation resulting in increased bone resorption and structural changes in the joint(Katz et al.,2021).

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The Mechanism of Heating Rate on the Secondary Recrystallization Evolution in Grain Oriented Silicon Steel

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Journal of Wuhan University of Technology(Materials Science) 2025年第1期 275-282页

作者：高倩 LI jun WANG Xianhui CAO Laifu GONG jian LI Bo Central Iron and Steel Research Institute Group Shougang Zhixin Electromagnetic Material R&D (Beijing) Co. Ltd. Beijing Shougang Co. Ltd.

Grain-oriented silicon steels were prepared at different heating rates during high temperature annealing, in which the evolution of magnetic properties, grain orientations and precipitates were studied. To illustrate the Zener factor, the diameter and number density of precipitates of interrupted testing samples were statistically calculated. The effect of precipitate ripening on the Goss texture and magnetic property was investigated. Data indicated that the trend of Zener factor was similar under different heating rates, first increasing and then decreasing, and that the precipitate maturing was greatly inhibited as the heating rate increased. Secondary recrystallization was developed at the temperature of 1 010 ℃ when a heating rate of 5 ℃/h was used, resulting in Goss, Brass and {110} oriented grains growing abnormally and a magnetic induction intensity of 1.90T. Furthermore, increasing the heating rate to 20 ℃/h would inhibit the development of undesirable oriented grains and obtain a sharp Goss texture. However, when the heating rate was extremely fast, such as 40 ℃/h, poor secondary recrystallization was developed with many island grains, corresponding to a decrease in magnetic induction intensity to 1.87 T. At a suitable heating rate of 20 ℃/h, the sharpest Goss texture and the highest magnetic induction of 1.94 T with an onset secondary recrystallization temperature of 1 020 ℃ were found among the experimental variables in this study. The heating rate affected the initial temperature of secondary recrystallization by controlling the maturation of precipitates, leading to the deviation and dispersion of Goss texture, thereby reducing the magnetic properties.

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Approximation Algorithms for Solving the 1-Line Minimum Steiner Tree of Line Segments Problem

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Journal of the Operations Research Society of China 2024年第3期12卷 729-755页

作者： jian-Ping Li Su-Ding Liu jun-ran Lichen Peng-Xiang Pan Wen-Cheng Wang Department of Mathematics Yunnan UniversityKunming650504YunnanChina School of Mathematics and Physics Beijing University of Chemical TechnologyBeijing650504China

We address the 1-line minimum Steiner tree of line segments(1L-MStT-LS)***,given a set S of n disjoint line segments in R^(2),we are asked to find the location of a line l and a set E_(l) of necessary line segments(i.e.,edges)such that a graph consisting of all line segments in S ∪ E_(l) plus this line l,denoted by T_(l)=(S,l,E_(l)),becomes a Steiner tree,the objective is to minimize total length of edges in E_(l) among all such Steiner ***,we are asked to find a set E_(0) of necessary edges such that a graph consisting of all line segments in S ∪ E_(0),denoted by T_(S)=(S,E_(0)),becomes a Steiner tree,the objective is to minimize total length of edges in E_(0) among all such Steiner trees,we refer to this new problem as the minimum Steiner tree of line segments(MStT-LS)*** addition,when two endpoints of each edge in Eo need to be located on two different line segments in S,respectively,we refer to that problem as the minimum spanning tree of line segments(MST-LS)*** obtain three main results:(1)Using technique of Voronoi diagram of line segments,we design an exact algorithm in time O(n log n)to solve the MST-LS problem;(2)we show that the algorithm designed in(1)is a 1.214-approximation algorithm to solve the MStT-LS problem;(3)using the combination of the algorithm designed in(1)as a subroutine for many times,a technique of finding linear facility location and a key lemma proved by techniques of computational geometry,we present a 1.214-approximation algorithm in time O(n^(3) log n)to solve the 1L-MStT-LS problem.

关键词： 1-Line minimum Steiner tree of line segments Minimum spanning tree of line segments Voronoi diagram of line segments Steiner ratio Approximation algorithms

Birkhoff Normal Form for the Derivative Nonlinear Schrodinger Equation

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Acta Mathematica Sinica,English Series 2022年第1期38卷 249-262页

作者： jian jun LIU School of Mathematics Sichuan UniversityChengdu 610065P.R.China

This paper is concerned with the derivative nonlinear Schr?dinger equation with periodic boundary *** obtain complete Birkhoff normal form of order *** an application,the long time stability for solutions of small amp... 详细信息

关键词： Birkhoff normal form derivative nonlinear Schr?dinger equation long time stability

Construction of a novel brittleness index equation and analysis of anisotropic brittleness characteristics for unconventional shale formations

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Petroleum Science 2020年第1期17卷 70-85页

作者： Ke-ran Qian Tao Liu jun-Zhou Liu Xi-Wu Liu Zhi-Liang He Da-jian jiang State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing 100083China Sinopec Key Laboratory of Seismic Elastic Wave Technology Beijing 100083China Key Laboratory of Shale Oil and Gas Exploration and Production SINOPECBeijing 100083China Ministry of Science and Technology SINOPECBeijing 100728China Sinopec Petroleum Exploration and Production Research Institute Beijing 100083China

The brittleness prediction of shale formations is of interest to researchers *** methods of brittleness prediction are usually based on isotropic models while shale is *** order to obtain a better prediction of shale brittleness,our study firstly proposed a novel brittleness index equation based on the Voigt–Reuss–Hill average,which combines two classical isotropic *** proposed method introduces upper and lower brittleness bounds,which take the uncertainty of brittleness prediction into *** addition,this method can give us acceptable predictions by using limited input ***,an anisotropic rock physics model was *** parameters were introduced into our model,which can be used to simulate the lamination of clay minerals and the dip angle of *** addition,rock physics templates have been built to analyze the sensitivity of brittleness ***,the effects of kerogen,pore structure,clay lamination and shale formation dip have been investigated in terms of *** prediction shows that the vertical/horizontal Young’s modulus is always below one while the vertical/horizontal Poisson’s ratio(PR)can be either greater or less than *** study finds different degrees of shale lamination may be the explanation for the random distribution of Vani(the ratio of vertical PR to horizontal PR).

关键词： Brittleness Shale Rock Physics Anisotropy Voigt–Reuss–Hill average

Effect of aspect ratio on triaxial compression of multi-sphere ellipsoid assemblies simulated using a discrete element method

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Particuology 2017年第3期15卷 49-62页

作者： jian Gong jun Liu State Key Laboratory of Coastal and Offshore Engineering Dalian University of Technology Dalian 116024 China

Here, we present a numerical investigation of the mechanical behavior of ellipsoids under triaxial com- pression for a range of aspect ratios. Our simulations use a multi-sphere approach in a three-dimensional discrete element method. All assemblies were prepared at their densest condition, and triaxial compres- sion tests were performed up to extremely large strains, until a critical state was reached. The stress-strain relationship and the void ratio-strain behavior were evaluated. We found that the stress-dilatancy rela- tionship of ellipsoids with different aspect ratios could be expressed as a linear equation. In particular, the aspect ratio influenced the position of the critical state lines for these assemblies. Particle-scale char- acteristics at the critical state indicate that particles tend to be flat lying, and the obstruction of particle rotation that occurs with longer particles affects their contact mechanics. Lastly, anisotropic coefficients related to aspect ratio were investigated to probe the microscopic origins of the macroscopic behavior. A detailed analysis of geometrical and mechanical anisotropies revealed the microscopic mechanisms underlying the dependency of peak and residual strengths on aspect ratio.

关键词： EllipsoidsAspect ratio DEM Triaxial compression Particle shape Macro-micro response