<div style="text-align:justify;"> Load identification method is one of the major technical difficulties of non-intrusive composite monitoring. Binary V-I trajectory image can reflect the original V-I t...<div style="text-align:justify;"> Load identification method is one of the major technical difficulties of non-intrusive composite monitoring. Binary V-I trajectory image can reflect the original V-I trajectory characteristics to a large extent, so it is widely used in load identification. However, using single binary V-I trajectory feature for load identification has certain limitations. In order to improve the accuracy of load identification, the power feature is added on the basis of the binary V-I trajectory feature in this paper. We change the initial binary V-I trajectory into a new 3D feature by mapping the power feature to the third dimension. In order to reduce the impact of imbalance samples on load identification, the SVM SMOTE algorithm is used to balance the samples. Based on the deep learning method, the convolutional neural network model is used to extract the newly produced 3D feature to achieve load identification in this paper. The results indicate the new 3D feature has better observability and the proposed model has higher identification performance compared with other classification models on the public data set PLAID. </div>展开更多
Magnetic absorbers with high permeability have significant advantages in lowfrequency and broadband electromagnetic wave(EMW)absorption.However,the insufficient magnetic loss and inherent high conductivity of existing...Magnetic absorbers with high permeability have significant advantages in lowfrequency and broadband electromagnetic wave(EMW)absorption.However,the insufficient magnetic loss and inherent high conductivity of existing magnetic absorbers limit the further expansion of EMW absorption bandwidth.Herein,the spinel(FeCoNiCrCu)_(3)O_(4) high-entropy oxides(HEO)are successfully constructed on the surface of FeCoNiCr_(0.4)Cu_(0.2) high-entropy alloys(HEA)through low-temperature oxygen bath treatment.On the one hand,HEO and HEA have different magnetocrystalline anisotropies,which is conducive to achieving continuous natural resonance to improve magnetic loss.On the other hand,HEO with low conductivity can serve as an impedance matching layer,achieving magneto-electric co-modulation.When the thickness is 5 mm,the minimum reflection loss(RL)value and absorption bandwidth(RL<−5 dB)of bi-phase high-entropy composites(BPHEC)can reach−12.8 dB and 633 MHz,respectively.The RCS reduction value of multilayer sample with impedance gradient characteristic can reach 18.34 dB m^(2).In addition,the BPHEC also exhibits temperaturestable EMW absorption performance,high Curie temperature,and oxidation resistance.The absorption bandwidth maintains between 593 and 691 MHz from−50 to 150℃.This work offers a new and tunable strategy toward modulating the electromagnetic genes for temperature-stable ultra-broadband megahertz EMW absorption.展开更多
As China’s higher education transitions from extensive expansion to intensive development,the‘New Liberal Arts’concept has emerged as a pivotal strategic direction for transforming humanities disciplines.This appro...As China’s higher education transitions from extensive expansion to intensive development,the‘New Liberal Arts’concept has emerged as a pivotal strategic direction for transforming humanities disciplines.This approach emphasizes interdisciplinary integration,parallel development of theory and practice,and optimizing talent cultivation models guided by societal demands.The diversified economic structure and high-quality development trajectory of the Guangdong-Hong Kong-Macao Greater Bay Area present new demands for talent cultivation,curriculum design,and pedagogical reform within university Human Resource Management(HRM)programs.Taking Guangzhou Huashang College as the research subject,this paper analyses the core competencies required for HRM programs under the New Liberal Arts framework through policy document analysis,literature review,and field research.It identifies shortcomings in the current curriculum system regarding knowledge structure,practical pathways,and cross-disciplinary integration.Guided by Outcome-Based Education(OBE)and Competency-Based Education(CBE)frameworks,a new curriculum architecture was designed comprising four pillars:general education and humanities literacy,professional core competencies,cross-disciplinary integration,and practical innovation.Practical explorations were undertaken in areas such as university-enterprise collaboration and industry-education integration.Preliminary outcomes demonstrate that the new scheme comprehensively enhances students’data comprehension,strategic awareness,and humanistic sensitivity,providing a reference paradigm for the high-quality development of HRM programs within the new liberal arts context.展开更多
<div style="text-align:justify;"> In the multi-objective of intelligent building load scheduling, aiming at the problem of how to select Pareto frontier scheme for multi-objective optimization algorith...<div style="text-align:justify;"> In the multi-objective of intelligent building load scheduling, aiming at the problem of how to select Pareto frontier scheme for multi-objective optimization algorithm, the current optimal scheme mechanism combined with multi-objective multi-verse algorithm is used to optimize the intelligent building load scheduling. The update mechanism is changed in updating the position of the universe, and the process of correction coding is omitted in the iterative process of the algorithm, which reduces the com-putational complexity. The feasibility and effectiveness of the proposed method are verified by the optimal scheduling experiments of residential loads. </div>展开更多
Metamaterials are widely used in electromagnetic radiation and camouflage for their flexible wavefront manipulation and polarization over a broad spectrum ranging from microwaves to optics.However,multispectral compat...Metamaterials are widely used in electromagnetic radiation and camouflage for their flexible wavefront manipulation and polarization over a broad spectrum ranging from microwaves to optics.However,multispectral compatible camouflage faces significant challenges due to tremendous scale differences of unit cells and desired radiative properties in various spectral regimes.This study assembles a micron-scale infrared emitter,a millimeter-scale microwave absorber,and a metal reflector to propose a hierarchical metamaterial that reduces microwave scattering and reflects low-infrared waves.As a proof of concept,laser etching micro-manufactures an upper infrared shielding layer with a periodic metal pattern.At the same time,bottom square frustum metastructure composites are fabricated and optimized based on genetic algorithms.Under the normal incidence transverse electromagnetic wave with a 90°azimuth angle,the hierarchical strategy and infrared unit create an asymmetric electric field distribution of local near-field coupling,which is conducive to generating additional resonance for broadening the absorption bandwidth.Experiments verify the multispectral camouflage,which shows a high absorption efficiency of more than 90%,ranging from 3.6 to 6.2 and from 8.4 to 18 GHz with a total thickness of 4.05 mm(0.049λmax).Due to the non-reflection of surrounding thermal signals in the infrared 2-22μm region,low-infrared emissivity(0.29)metamaterials can adapt to various thermal backgrounds.This methodology can provide a novel route for fabricating multispectral camouflage devices.展开更多
HZSM-5/MCM-41 molecular sieve (H-ZM) catalysts with well-defined micro/mesoporous structures were synthesized and showed high performance for selective synthesis of triacetin via the esterification reaction of glycero...HZSM-5/MCM-41 molecular sieve (H-ZM) catalysts with well-defined micro/mesoporous structures were synthesized and showed high performance for selective synthesis of triacetin via the esterification reaction of glycerol with acetic acid. The conversion of glycerol was demonstrated to be 100% and the triacetin selectivity was over 91%, which can be attributed to the synergistic effect regarding suitable acidic property, excellent diffusion efficiency and good stability derived from the combined advantages of microporous molecular sieve HZSM-5 and mesoporous molecular sieve MCM-41.展开更多
The scarcity and weak durability of metal,especially precious metal catalysts are big obstacles for their large-scale application in many reactions.The state-of-the-art of the catalytic science prefers such type of ca...The scarcity and weak durability of metal,especially precious metal catalysts are big obstacles for their large-scale application in many reactions.The state-of-the-art of the catalytic science prefers such type of catalysts,which can replace metal-based catalysts to alleviate energy and environmental crises and exhibit catalytic performance comparable to or even exceeding these metal catalysts.Herein,we report that N-doped porous carbon(NKC)derived from cheap and abundant radish can be employed as versatile and efficient bifunctional catalysts in both the catalytic reduction of 4-nitrophenol(NRR)and oxidation of styrene(SOR).The series of NKC catalysts were prepared with a simple and facile one-pot strategy by coupling the N-doping,carbonization and KOH activation processes.These catalysts show hierarchical porosity,with the specific surface area,total pore volume and N-doping content ranging from 918.9-3062.7 m^2 g^-1,1.01-2.04 cm^3 g^-1 and 1.29-15.3 at%,respectively.Interestingly,our finding suggests that the catalytic performance is not directly related to these parameters but correlates positively with the content of graphitic N dopants,which is the dominant contributor for impelling both the NRR and SOR.Another intriguing finding is that for both reactions,the optimal catalyst was found to be the NKC-3-800 which possesses the highest graphitic N content of 3.13 at%.In addition,to gain insight into the catalytic behavior,analyses of kinetics and thermodynamics were performed,and the catalytic mechanisms were postulated.This work paves the way for the construction of biomass-derived N-doped carbon catalysts for bi-or even multi-functional applications in various organic reactions.展开更多
Metamaterials with artificial designability and perfect absorption provide a novel design method for the manipulation and attenuation of microwaves.However,owing to the limitations of meta-atomic reso-nance effect and...Metamaterials with artificial designability and perfect absorption provide a novel design method for the manipulation and attenuation of microwaves.However,owing to the limitations of meta-atomic reso-nance effect and the lossless medium,it is difficult to achieve effective microwave absorption in a broad-band frequency range.Hence,an ultra-wideband metamaterial absorber(UWMA)composed of two mag-netic media and a metasurface was designed,and the absorption bandwidth of 2.9 to 18 GHz for 90%absorptivity under normal incidence was achieved,covering almost the entire S,C,X,and Ku bands.Through detailed investigation of equivalent circuit,equivalent medium theory,electromagnetic field dis-tribution and front-back interface interference,the internal physical working mechanism was clarified essentially.In addition,the multi-environment adaptabilities of the proposed absorber,including polariza-tion sensitivity,large angle incidence,dual-station radar stealth,bearing capacity and corrosion resistance,were analyzed.The proposed metamaterial absorber presents an effective way to achieve ultra-wideband absorption and compatibility with environmental adaptability,and provides a new way of thinking for intelligent full-band stealth technology.展开更多
Great efforts have been devoted to the developing of simple,efficient and stable heterogeneous catalysts for the styrene epoxidation reaction(SER).Metal oxides can be of industrial importance by offering an economic a...Great efforts have been devoted to the developing of simple,efficient and stable heterogeneous catalysts for the styrene epoxidation reaction(SER).Metal oxides can be of industrial importance by offering an economic and green route for selectively converting styrene into styrene oxide(SO).Herein,by treating the pristine porous 2D Co3O4 sheets with NaBH4 solution,a novel hierarchical structure,i.e.,0D Co3O4 nanoparticles decorated on 2D porous Co3O4 sheets,was obtained.This simple solution reduction strategy not only realizes the morphology evolution,but also induces the modification of the valence states of metal ions and the simultaneous generation of surface oxygen vacancies.The hierarchical 0D/2D Co3O4 hybrids rich in oxygen vacancies(OV‐Co3O4)exhibit a much better SER performance than the Co3O4 sheets(P‐Co3O4),with the yield of SO more than doubled.The excellent catalytic performance of the OV‐Co3O4 can be ascribed to the synergistic effects regarding the hierarchical porous structure,the modification of surface chemical composition and the creation of surface oxygen vacancies.展开更多
The reconfigurable metasurfaces which can regulate the microwave absorption performance at the sub wavelength scale provide a possibility to construct intelligent stealth system.However,the existing reconfigurable-met...The reconfigurable metasurfaces which can regulate the microwave absorption performance at the sub wavelength scale provide a possibility to construct intelligent stealth system.However,the existing reconfigurable-metasurface-based absorbers seriously limit the medium and long-distance regulation in practical application due to the complex circuit path and regulation mode.Here,an infrared-coded dual-polarized metasurface absorber(IDMA)with remote-control mode was proposed,which realized the realtime dynamic regulation of the intensity and frequency range of absorption peaks by combining the infrared-coding remotecontrol technology with the active metasurface absorber.The proposed remote-control system can switch the 8-bit binary coding sequences stored in the microcontroller unit(MCU)by an infrared transceiver,so as to regulate the state of active devices under X-and Y-polarizations,respectively.The experimental results showed that the reflection/absorption responses can be regulated by switching different binary codes,and the reflection loss(RL)can be tuned below−7.5 dB(absorptivity over 82%)in wide range of 6.20–18 GHz.Furthermore,the corresponding equivalent circuit model was established and the distributions of surface current and electric field were analyzed to elucidate the dynamic reconfigurable mechanism of the metasurface absorber.The proposed IDMA,which combines intelligent electronic technology with active metasurface absorber,creatively realizes the remote control of active metasurface absorber and opens up a new way for the stealth technology of smart absorber in the future.展开更多
文摘<div style="text-align:justify;"> Load identification method is one of the major technical difficulties of non-intrusive composite monitoring. Binary V-I trajectory image can reflect the original V-I trajectory characteristics to a large extent, so it is widely used in load identification. However, using single binary V-I trajectory feature for load identification has certain limitations. In order to improve the accuracy of load identification, the power feature is added on the basis of the binary V-I trajectory feature in this paper. We change the initial binary V-I trajectory into a new 3D feature by mapping the power feature to the third dimension. In order to reduce the impact of imbalance samples on load identification, the SVM SMOTE algorithm is used to balance the samples. Based on the deep learning method, the convolutional neural network model is used to extract the newly produced 3D feature to achieve load identification in this paper. The results indicate the new 3D feature has better observability and the proposed model has higher identification performance compared with other classification models on the public data set PLAID. </div>
基金Supported by Program for the National Natural Science Foundation of China(No.52071053,U1704253,52103334)the Fundamental Research Funds for the Central Universities(DUT24GF102)the Shandong Province Natural Science Youth Fund(ZR2024QA134)。
文摘Magnetic absorbers with high permeability have significant advantages in lowfrequency and broadband electromagnetic wave(EMW)absorption.However,the insufficient magnetic loss and inherent high conductivity of existing magnetic absorbers limit the further expansion of EMW absorption bandwidth.Herein,the spinel(FeCoNiCrCu)_(3)O_(4) high-entropy oxides(HEO)are successfully constructed on the surface of FeCoNiCr_(0.4)Cu_(0.2) high-entropy alloys(HEA)through low-temperature oxygen bath treatment.On the one hand,HEO and HEA have different magnetocrystalline anisotropies,which is conducive to achieving continuous natural resonance to improve magnetic loss.On the other hand,HEO with low conductivity can serve as an impedance matching layer,achieving magneto-electric co-modulation.When the thickness is 5 mm,the minimum reflection loss(RL)value and absorption bandwidth(RL<−5 dB)of bi-phase high-entropy composites(BPHEC)can reach−12.8 dB and 633 MHz,respectively.The RCS reduction value of multilayer sample with impedance gradient characteristic can reach 18.34 dB m^(2).In addition,the BPHEC also exhibits temperaturestable EMW absorption performance,high Curie temperature,and oxidation resistance.The absorption bandwidth maintains between 593 and 691 MHz from−50 to 150℃.This work offers a new and tunable strategy toward modulating the electromagnetic genes for temperature-stable ultra-broadband megahertz EMW absorption.
基金Guangzhou Huashang College 2024 Demonstration Major Program(Project No.:HS2024SFZY09)。
文摘As China’s higher education transitions from extensive expansion to intensive development,the‘New Liberal Arts’concept has emerged as a pivotal strategic direction for transforming humanities disciplines.This approach emphasizes interdisciplinary integration,parallel development of theory and practice,and optimizing talent cultivation models guided by societal demands.The diversified economic structure and high-quality development trajectory of the Guangdong-Hong Kong-Macao Greater Bay Area present new demands for talent cultivation,curriculum design,and pedagogical reform within university Human Resource Management(HRM)programs.Taking Guangzhou Huashang College as the research subject,this paper analyses the core competencies required for HRM programs under the New Liberal Arts framework through policy document analysis,literature review,and field research.It identifies shortcomings in the current curriculum system regarding knowledge structure,practical pathways,and cross-disciplinary integration.Guided by Outcome-Based Education(OBE)and Competency-Based Education(CBE)frameworks,a new curriculum architecture was designed comprising four pillars:general education and humanities literacy,professional core competencies,cross-disciplinary integration,and practical innovation.Practical explorations were undertaken in areas such as university-enterprise collaboration and industry-education integration.Preliminary outcomes demonstrate that the new scheme comprehensively enhances students’data comprehension,strategic awareness,and humanistic sensitivity,providing a reference paradigm for the high-quality development of HRM programs within the new liberal arts context.
文摘<div style="text-align:justify;"> In the multi-objective of intelligent building load scheduling, aiming at the problem of how to select Pareto frontier scheme for multi-objective optimization algorithm, the current optimal scheme mechanism combined with multi-objective multi-verse algorithm is used to optimize the intelligent building load scheduling. The update mechanism is changed in updating the position of the universe, and the process of correction coding is omitted in the iterative process of the algorithm, which reduces the com-putational complexity. The feasibility and effectiveness of the proposed method are verified by the optimal scheduling experiments of residential loads. </div>
基金supported by the National Natural Science Foundation of China(Nos.52103334,52071053,and U1704253)China Postdoctoral Science Foundation(Nos.2020M680946,2020M670748)the Fundamental Research Funds for the Central Universities(No.DUT20GF111).
文摘Metamaterials are widely used in electromagnetic radiation and camouflage for their flexible wavefront manipulation and polarization over a broad spectrum ranging from microwaves to optics.However,multispectral compatible camouflage faces significant challenges due to tremendous scale differences of unit cells and desired radiative properties in various spectral regimes.This study assembles a micron-scale infrared emitter,a millimeter-scale microwave absorber,and a metal reflector to propose a hierarchical metamaterial that reduces microwave scattering and reflects low-infrared waves.As a proof of concept,laser etching micro-manufactures an upper infrared shielding layer with a periodic metal pattern.At the same time,bottom square frustum metastructure composites are fabricated and optimized based on genetic algorithms.Under the normal incidence transverse electromagnetic wave with a 90°azimuth angle,the hierarchical strategy and infrared unit create an asymmetric electric field distribution of local near-field coupling,which is conducive to generating additional resonance for broadening the absorption bandwidth.Experiments verify the multispectral camouflage,which shows a high absorption efficiency of more than 90%,ranging from 3.6 to 6.2 and from 8.4 to 18 GHz with a total thickness of 4.05 mm(0.049λmax).Due to the non-reflection of surrounding thermal signals in the infrared 2-22μm region,low-infrared emissivity(0.29)metamaterials can adapt to various thermal backgrounds.This methodology can provide a novel route for fabricating multispectral camouflage devices.
基金Supported by the National Natural Science Foundation of China(21620102007)the Natural Science Foundation for High Education of Jiangsu Province(17KJB530011)+1 种基金the Science and Technology Innovation Foundation of Yangzhou University(2017CXJ015)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘HZSM-5/MCM-41 molecular sieve (H-ZM) catalysts with well-defined micro/mesoporous structures were synthesized and showed high performance for selective synthesis of triacetin via the esterification reaction of glycerol with acetic acid. The conversion of glycerol was demonstrated to be 100% and the triacetin selectivity was over 91%, which can be attributed to the synergistic effect regarding suitable acidic property, excellent diffusion efficiency and good stability derived from the combined advantages of microporous molecular sieve HZSM-5 and mesoporous molecular sieve MCM-41.
文摘The scarcity and weak durability of metal,especially precious metal catalysts are big obstacles for their large-scale application in many reactions.The state-of-the-art of the catalytic science prefers such type of catalysts,which can replace metal-based catalysts to alleviate energy and environmental crises and exhibit catalytic performance comparable to or even exceeding these metal catalysts.Herein,we report that N-doped porous carbon(NKC)derived from cheap and abundant radish can be employed as versatile and efficient bifunctional catalysts in both the catalytic reduction of 4-nitrophenol(NRR)and oxidation of styrene(SOR).The series of NKC catalysts were prepared with a simple and facile one-pot strategy by coupling the N-doping,carbonization and KOH activation processes.These catalysts show hierarchical porosity,with the specific surface area,total pore volume and N-doping content ranging from 918.9-3062.7 m^2 g^-1,1.01-2.04 cm^3 g^-1 and 1.29-15.3 at%,respectively.Interestingly,our finding suggests that the catalytic performance is not directly related to these parameters but correlates positively with the content of graphitic N dopants,which is the dominant contributor for impelling both the NRR and SOR.Another intriguing finding is that for both reactions,the optimal catalyst was found to be the NKC-3-800 which possesses the highest graphitic N content of 3.13 at%.In addition,to gain insight into the catalytic behavior,analyses of kinetics and thermodynamics were performed,and the catalytic mechanisms were postulated.This work paves the way for the construction of biomass-derived N-doped carbon catalysts for bi-or even multi-functional applications in various organic reactions.
基金National Natural Science Foundation of China(Nos.52103334,52071053,and U1704253)China Postdoctoral Science Foundation(Nos.2020M680946 and 2020M670748)+1 种基金Fundamental Research Funds for the Central Universities(No.DUT20GF111)Fundamental Research Funds of Shaanxi Key Laboratory of Artificially–Structured Functional Materials and Devices(No.AFMD–KFJJ–21102).
文摘Metamaterials with artificial designability and perfect absorption provide a novel design method for the manipulation and attenuation of microwaves.However,owing to the limitations of meta-atomic reso-nance effect and the lossless medium,it is difficult to achieve effective microwave absorption in a broad-band frequency range.Hence,an ultra-wideband metamaterial absorber(UWMA)composed of two mag-netic media and a metasurface was designed,and the absorption bandwidth of 2.9 to 18 GHz for 90%absorptivity under normal incidence was achieved,covering almost the entire S,C,X,and Ku bands.Through detailed investigation of equivalent circuit,equivalent medium theory,electromagnetic field dis-tribution and front-back interface interference,the internal physical working mechanism was clarified essentially.In addition,the multi-environment adaptabilities of the proposed absorber,including polariza-tion sensitivity,large angle incidence,dual-station radar stealth,bearing capacity and corrosion resistance,were analyzed.The proposed metamaterial absorber presents an effective way to achieve ultra-wideband absorption and compatibility with environmental adaptability,and provides a new way of thinking for intelligent full-band stealth technology.
基金supported by the Natural Science Foundation for High Education of Jiangsu Province (17KJB530011)the Science and Technology Innovation Foundation of Yangzhou University (2017CXJ015)the Priority Academic Program Development of Jiangsu Higher Education Institu-tions (PAPD)~~
文摘Great efforts have been devoted to the developing of simple,efficient and stable heterogeneous catalysts for the styrene epoxidation reaction(SER).Metal oxides can be of industrial importance by offering an economic and green route for selectively converting styrene into styrene oxide(SO).Herein,by treating the pristine porous 2D Co3O4 sheets with NaBH4 solution,a novel hierarchical structure,i.e.,0D Co3O4 nanoparticles decorated on 2D porous Co3O4 sheets,was obtained.This simple solution reduction strategy not only realizes the morphology evolution,but also induces the modification of the valence states of metal ions and the simultaneous generation of surface oxygen vacancies.The hierarchical 0D/2D Co3O4 hybrids rich in oxygen vacancies(OV‐Co3O4)exhibit a much better SER performance than the Co3O4 sheets(P‐Co3O4),with the yield of SO more than doubled.The excellent catalytic performance of the OV‐Co3O4 can be ascribed to the synergistic effects regarding the hierarchical porous structure,the modification of surface chemical composition and the creation of surface oxygen vacancies.
基金the National Natural Science Foundation of China(Nos.52103334,52071053,and U1704253)China Postdoctoral Science Foundation(Nos.2020M680946 and 2020M670748)the Fundamental Research Funds for the Central Universities(No.DUT20GF111).
文摘The reconfigurable metasurfaces which can regulate the microwave absorption performance at the sub wavelength scale provide a possibility to construct intelligent stealth system.However,the existing reconfigurable-metasurface-based absorbers seriously limit the medium and long-distance regulation in practical application due to the complex circuit path and regulation mode.Here,an infrared-coded dual-polarized metasurface absorber(IDMA)with remote-control mode was proposed,which realized the realtime dynamic regulation of the intensity and frequency range of absorption peaks by combining the infrared-coding remotecontrol technology with the active metasurface absorber.The proposed remote-control system can switch the 8-bit binary coding sequences stored in the microcontroller unit(MCU)by an infrared transceiver,so as to regulate the state of active devices under X-and Y-polarizations,respectively.The experimental results showed that the reflection/absorption responses can be regulated by switching different binary codes,and the reflection loss(RL)can be tuned below−7.5 dB(absorptivity over 82%)in wide range of 6.20–18 GHz.Furthermore,the corresponding equivalent circuit model was established and the distributions of surface current and electric field were analyzed to elucidate the dynamic reconfigurable mechanism of the metasurface absorber.The proposed IDMA,which combines intelligent electronic technology with active metasurface absorber,creatively realizes the remote control of active metasurface absorber and opens up a new way for the stealth technology of smart absorber in the future.
