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Anisotropic and nonlinear metasurface for multiple functions

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Science China(Information Sciences) 2021年第9期64卷 165-174页

作者： Zhangjie LUO Xueyao REN qiang wang qiang CHENG Tiejun CUI State Key Laboratory of Millimeter Waves School of Information Science and EngineeringSoutheast University Pazhou Lab Air and Missile Defense College Air Force Engineering University

We present a novel anisotropic and nonlinear metasurface integrated with multiple functions of diffuse scattering, beam splitting, and normal reflection, which can be switched in real time by tuning the polarization state or power level of the incident microwave. The key lies in the two judiciously designed anisotropic nonlinear particles in subwavelength scales that possess opposite reflection phases under one polarization and the same nonlinear power-dependent reflection phases under the orthogonal polarization. These properties are demonstrated comprehensively via comparisons between their reflection responses, receiving abilities, and nonlinear circuitry behaviors. In addition, both the spatial arrangement and the electrically enabling strategy of the particles are underpinned to pursue the proposed functions, which are verified through numerical simulations and measurements. When the metasurface is illuminated by plane waves coming from the direction perpendicular to it, a significant beam splitting effect is achieved with strong x-polarized incidence,which is switched to a specular reflection when the incoming power decreases. Under y-polarization,a diffuse scattering phenomenon is obtained, which is not dependent on the incident intensity. The study is expected to offer new solutions to many electromagnetic scenarios involving energy transmissions and protections.

关键词： multi-function metasurface nonlinear anisotropic polarization

ERROR ESTIMATE ON A FULLY DISCRETE LOCAL DISCONTINUOUS GALERKIN METHOD FOR LINEAR CONVECTION-DIFFUSION PROBLEM

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Journal of Computational Mathematics 2013年第3期31卷 283-307页

作者： Haijin wang qiang Zhang Department of Mathematics Nanjing University Nanjing 210093 China

In this paper we present the error estimate for the fully discrete local discontinuous Galerkin algorithm to solve the linear convection-diffusion equation with Dirichlet boundary condition in one dimension. The time is advanced by the third order explicit total variation diminishing Runge-Kutta method under the reasonable temporal-spatial condition as general. The optimal error estimate in both space and time is obtained by aid of the energy technique, if we set the numerical flux and the intermediate boundary condition properly.

关键词： Runge-Kutta Local discontinuous Galerkin method Convection-diffusion equation Error estimate.

基于SCIATRAN的临近空间氧气光谱敏感性分析

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光谱学与光谱分析 2025年第1期45卷 170-178页

作者：叶松胡双寒熊伟李树王新强王方原汪杰君桂林电子科技大学光电工程学院广西桂林541004 中国科学院安徽光学精密机械研究所中国科学院通用光学定标与表征技术重点实验室安徽合肥230031 广西光电信息处理重点实验室广西桂林541004

临近空间大气温度场的研究具有重要的科学意义,根据全时相大气温度示踪物辐射机制与分布特征研究表明,氧气作为大气的主要成分之一,广泛分布于临近空间且辐射强度明显,所以氧气探测是研究临近空间温度变化的重要基础。临近空间氧气探测... 详细信息

临近空间大气温度场的研究具有重要的科学意义,根据全时相大气温度示踪物辐射机制与分布特征研究表明,氧气作为大气的主要成分之一,广泛分布于临近空间且辐射强度明显,所以氧气探测是研究临近空间温度变化的重要基础。临近空间氧气探测主要是依据太阳辐射的短波红外部分被大气层氧气分子吸收得到的吸收谱线,该谱线携带着氧气含量等重要信息。利用探测器得到的氧气光谱进行高精度反演可以得到温度等信息。探测过程中的太阳天顶角、方位角、临边切高及气溶胶参数等因素对氧气影响不同,基于SCIATRAN模型分析氧气对不同参数的敏感性。通过对探测方式和环境因素引起的辐射亮度变化来分析计算氧气对其敏感性。结果表明:氧气的辐射亮度在天顶角为60°以下是随天顶角增大而增大的,但在超过60°后变化随之相反,一天内的太阳天顶角对于氧气的辐射亮度影响不超过0.01 W/m^(2)/nm/sr,且差值不超过7%;氧气辐亮度随方位角增大而减小;氧气辐射亮度随切线高增加而减小,且减小幅度逐渐下降;气溶胶类型对氧气辐射亮度的影响差值比例在10%以内;气溶胶季节对氧气辐射亮度影响是春夏季节要大于秋冬季节;不同气溶胶类型下的气溶胶光学厚度倍数对氧气辐射亮度影响的差值比例均在30%以内,且农村与海洋型气溶胶下光学厚度倍数与辐射亮度成正比,城市型气溶胶下与之相反。仿真数据的结果与实测数据结果对比分析验证了SCIATRAN模型仿真数据的有效性和可行性。该研究为临近空间的氧气探测提供了科学依据,为临近空间的反演等相关研究领域提供参考。

关键词：临近空间氧气辐射传输敏感性

A multifunctional stealthy material for wireless sensing and active camouflage driven by configurable polarization

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Journal of Materials Science & Technology 2023年第1期132卷 42-49页

作者： Min Zhang Mao-Sheng Cao qiang-qiang wang Xi-Xi wang Wen-qiang Cao Hui-Jing Yang Jie Yuan School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China Department of Physics Beijing Technology and Business UniversityBeijing 100048China School of Electrical and Electronic Engineering Nanyang Technological University639798Singapore Department of Physics Tangshan Normal UniversityTangshan 063000China School of Information Engineering Minzu University of ChinaBeijing 100081China

The dipole species transformation and polarization relaxation configuration are achieved by changing the cobalt ion stoichiometry,which precisely tailors the electromagnetic attenuation performance of bismuth iron cobalt *** the stoichiometric ratio of Fe:Co is 19:1,the optimal reflection loss reaches-60 *** high electromagnetic attenuation performance significantly improve the linear sensitivity of the strain response and active customized stealth capability of the designed multifunctional capacitor-like ***,the wireless multifunctional design integrates energy attenuaten of electromagnetic wave with the wireless sensing and active camouflage functions for the first *** work provides an important step for the realization of electromagnetical multifunctional applications including electromag-netic protection and electromagnetic sensing in artificial beings,medical health and even space travel.

关键词： Electromagnetic absorption Polarization relaxation Electromagnetic sensing Active camouflage

Agricultural products processing characteristics and quality evaluation

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Journal of Integrative Agriculture 2018年第5期17卷 975-976页

作者： wang qiang Institute of Food Science and TechnologyChinese Academy of Agricultural Sciences Beijing 100193 P.R.China

Cereal,oil and fruit are the foundation of human survival which attracted much attention by their quality characteristics and ***,there are about 410 000 wheat resources（Drikvand et al.2013）,215 000 rice resources（... 详细信息

关键词：特征和产品处理评估农业资源

Viscosity and structure of CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags for continuous casting of high titanium steel with different Tio2 absorption

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Journal of Iron and Steel Research International 2024年第8期31卷 1936-1946页

作者： Ya-tao Cui Xue-you wang Xu-bin Zhang qiang-qiang wang Sheng-ping He College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

The effect of TiO_(2) absorption into two different CaO-BaO-SiO_(2)-Al_(2)O_(3)-based mold slags from the steel plant on the viscosity,melting performance and microstructure of slags was investigated through the measurement of the viscosity-temperature relationship,melting temperature and Raman *** parameter of the number of non-bridging oxygen per tetrahedrally-coordinated atom(NBO/T)was also calculated to explain the microstructure variation of molten slags with different TiO_(2) *** variation of the actual slag consumption and the depth of the liquid slag in mold was explained through the comparison of the viscosity and the melting temperature of two different *** viscosity of mold slags(basicity=0.6)decreased from 1.1 to 0.68 Pa s with the increase in the Ti0_(2) absorption from 0 to 10%,while that of slags(basicity=0.7)decreased from 0.76 to 0.56 Pa s with the Ti0_(2) absorption from 0 to 6%.The activation energy of both two groups of slags had the tendency to decrease with the increasing TiO_(2) *** network structure of both two groups of slags measured by the Raman spectra showed that the fraction of complex structure units(Q^(1),Q^(2),Q^(3) and A1-O-Al)decreased and simple structure units(Al-O-and Q^(0))increased with the increase in TiO_(2) ***/T also increased with the increase in the TiO2 absorption,indicating that the absorption of TiO_(2) into slags resulted in the destruction of silicate/aluminate ***,the absorption of TiO_(2) into the current CaO-BaO-SiO_(2)-Al_(2)O_(3) mold slags decreased the degree of polymerization of these slags and then led to the decrease of viscosity.

关键词： Mold slag Viscosity Melting temperature Slag consumption Liquid slag depth Structure

Desulfurization of rejected electrolytic manganese metal by electroslag remelting furnace with a water-cooled electrode

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Journal of Iron and Steel Research International 2023年第7期30卷 1411-1425页

作者： Ru Lu Ran-ran Yu Guang-qiang Li Yu Liu qiang wang Hai-chuan wang School of Metallurgical Engineering Anhui University of TechnologyMa’anshan 243002AnhuiChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of Education Wuhan University of Science and TechnologyWuhan 430081HubeiChina

Remelting rejected electrolytic manganese metal (EMM) scrap was investigated by electroslag remelting (ESR) process through industrial experiment. The results indicated that the ANF-6 slag (70 wt.% CaF_(2) + 30 wt.% Al_(2)O_(3)) and deoxidizer could promote the desulfurization of ESR manganese in an air atmosphere. Under an air atmosphere, the sulfur in the ingot decreased to 0.0534 wt.% with a desulfurization ratio of ESR manganese of 53.2% by using ANF-6 slag and water-cooled copper electrode electroslag remelting rejected EMM scrap, suggesting its efficient removal. The electroslag ingots exhibited uneven chemical composition in an air atmosphere and cooling condition of the ESR process. The metal manganese could be oxidized by electroslag remelting of rejected EMM scrap in an air atmosphere with MnO content in the final slag of 21.9 wt.%. Besides, the activity of MnO in slag increased with increasing remelting temperature, resulting in a reduction in the slag–manganese sulfur partition ratio and desulfurization ratio. Moreover, with the accumulation of sulfur in slag and the oxidation of metallic manganese liquid, the slag showed a lower cleanliness and more oxidation, leading to an increase in sulfur and oxygen content in the electroslag ingot with the increase in ingot height.

关键词： Rejected electrolytic manganese metal scrap Desulfurization Electroslag remelting Thermodynamics

A new model to simulate infrared radiation from an aircraft exhaust system

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Chinese Journal of Aeronautics 2017年第2期30卷 651-662页

作者： Zhou Yue wang qiang Li Ting School of Energy and Power Engineering Beihang University Beijing 100083 China Collaborative Innovation Center Jor Advanced Aero-Engine Beijing 100083 China

A multi-scale narrow band correlated-k distribution（MSNBCK） model is developed to simulate infrared radiation（IR） from an exhaust system of a typical aircraft *** this model,an approximate approach instead of statistically uncorrelated assumption is used to treat overlapping bands in gas *** significantly reduces the requirement for computing power through converting the exponential increase of computing power consumption with the increase of participating gas species to linear ***,MSNBCK model has a great advantage compared with conventional methods which can estimate each species＇ contribution to the total gas mixture radiation *** by line（LBL） results,experimental data and other results in the references are used to evaluate this new model,which demonstrates its advantage in terms of accuracy and computing *** coupling this model and finite volume method（FVM） into radiative transfer equation（RTE）,a comparative study is conducted to simulate IR signature from the exhaust *** results indicate that wall＇s IR emission should be considered in both 3-5 μm and8-14 μm bands while gases＇ IR emission plays an important role only in 3-5 μm *** plume IR radiation,carbon dioxide＇s emission is much more significant than that of water vapor in both3-5μm and 8-14 μm *** in 3-5 μm band,the water vapor＇s IR signal can even be neglected compared with that of carbon dioxide.

关键词： Computational efficiency Infrared radiation k-distribution Multi-scale method Radiative contribution

Identifying the sensitive area in adaptive observation for predicting the upstream Kuroshio transport variation in a 3-D ocean model

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Science China Earth Sciences 2017年第5期60卷 866-875页

作者： ZHANG Kun MU Mu wang qiang Key Laboratory of Ocean Circulation and Waves Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China University of Chinese Academy of Sciences Beijing 100049 China Institute of Atmospheric Sciences Fudan University Shanghai 200433 China Laboratory for Ocean and Climate Dynamics Qingdao National Laboratory for Marine Science and Technology Qingdao 266237 China

Using the conditional nonlinear optimal perturbation(CNOP) approach, sensitive areas of adaptive observation for predicting the seasonal reduction of the upstream Kuroshio transport(UKT) were investigated in the Regional Ocean Modeling System(ROMS). The vertically integrated energy scheme was utilized to identify sensitive areas based on two factors: the specific energy scheme and sensitive area size. Totally 27 sensitive areas, characterized by three energy schemes and nine sensitive area sizes, were evaluated. The results show that the total energy(TE) scheme was the most effective because it includes both the kinetic and potential components of CNOP. Generally, larger sensitive areas led to better predictions. The size of 0.5% of the model domain was chosen after balancing the effectiveness and efficiency of adaptive observation. The optimal sensitive area OSen was determined accordingly. Sensitivity experiments on OSen were then conducted, and the following results were obtained:(1) In OSen, initial errors with CNOP or CNOP-like patterns were more likely to yield worse predictions, and the CNOP pattern was the most unstable.(2) Initial errors in OSen rather than in other regions tended to cause larger prediction errors. Therefore, adaptive observation in OSen can be more beneficial for predicting the seasonal reduction of UKT.

关键词： Sensitive area Adaptive observation The upstream Kuroshio transport Conditional nonlinear optimal perturbation(CNOP)