The dynamic control of the metasurface opens up a vital technological approach for the development of multifunctional integrated optical devices.The magnetic field manipulation has the advantages of sub-nanosecond ult...The dynamic control of the metasurface opens up a vital technological approach for the development of multifunctional integrated optical devices.The magnetic field manipulation has the advantages of sub-nanosecond ultra-fast response,non-contact,and continuous adjustment.Thus,the magnetically controllable metasurface has attracted significant attention in recent years.This study introduces the basic principles of the Faraday and Kerr effect of magneto-optical(MO)materials.It classifies the typical MO materials according to their properties.It also summarizes the physical mechanism of different MO metasurfaces that combine the MO effect with plasmonic or dielectric resonance.Besides,their applications in the nonreciprocal device and MO sensing are demonstrated.The future perspectives and challenges of the research on MO metasurfaces are discussed.展开更多
Active metasurfaces have recently attracted more attention since they can make the light manipulation be versatile and real-time. Metasurfaces-based holography possesses the advantages of high spatial resolution and e...Active metasurfaces have recently attracted more attention since they can make the light manipulation be versatile and real-time. Metasurfaces-based holography possesses the advantages of high spatial resolution and enormous information capacity for applications in optical displays and encryption. In this work, a tunable polarization multiplexing holographic metasurface controlled by an external magnetic field is proposed. The elaborately designed nanoantennas are arranged on the magneto-optical intermediate layer, which is placed on the metallic reflecting layer. Since the non-diagonal elements of the dielectric tensor of the magneto-optical material become non-zero values once the external magnetic field is applied,the differential absorption for the left and right circularly polarized light can be generated. Meanwhile, the amplitude and phase can be flexibly modulated by changing the sizes of the nanoantennas. Based on this, the dynamic multichannel holographic display of metasurface in the linear and circular polarization channels is realized via magnetic control, and it can provide enhanced security for optical information storage. This work paves the way for the realization of magnetically controllable phase modulation, which is promising in dynamic wavefront control and optical information encryption.展开更多
Community-based social organizations play a vital role in grassroots governance but generally face resource dependence dilemmas that constrain their capacity building and sustainable development.Based on Resource Depe...Community-based social organizations play a vital role in grassroots governance but generally face resource dependence dilemmas that constrain their capacity building and sustainable development.Based on Resource Dependence Theory(RDT),this study addresses the limitations of existing research,such as the lack of an integrated framework and insufficient exploration of bidirectional interaction mechanisms,by systematically analyzing the current state of resource dependence among community-based social organizations.The study constructs a three-dimensional capacity-building strategy:optimizing dependency structures through the establishment of a diversified resource supply network;enhancing resource acquisition capabilities through identification,integration,and utilization of resources;and cultivating organizational autonomy through governance structures,professional competencies,and organizational culture.These strategies provide both theoretical support and practical pathways for community-based social organizations to overcome resource constraints and achieve sustainable development.展开更多
基金the financial support from the National Key Research and Development Program of China(No.2017YFB1002900)Fok Ying-Tong Education Foundation of China(No.161009)+1 种基金the National Natural Science Foundation of China(Grant No.61775019)Beijing Outstanding Young Scientist Program(No.BJJWZYJH01201910007022).
文摘The dynamic control of the metasurface opens up a vital technological approach for the development of multifunctional integrated optical devices.The magnetic field manipulation has the advantages of sub-nanosecond ultra-fast response,non-contact,and continuous adjustment.Thus,the magnetically controllable metasurface has attracted significant attention in recent years.This study introduces the basic principles of the Faraday and Kerr effect of magneto-optical(MO)materials.It classifies the typical MO materials according to their properties.It also summarizes the physical mechanism of different MO metasurfaces that combine the MO effect with plasmonic or dielectric resonance.Besides,their applications in the nonreciprocal device and MO sensing are demonstrated.The future perspectives and challenges of the research on MO metasurfaces are discussed.
基金supported by the National Key R&D Program of China (Nos. 2021YFB2801803 and 2021YFA1401200)the Natural Science Foundation of Shandong Province(No. ZR2023LZH001)+3 种基金the Beijing Outstanding Young Scientist Program (No. BJJWZYJH01201910007022)the National Natural Science Foundation of China (Nos. U21A20140 and 92050117)the Fok Ying-Tong Education Foundation of China(No. 161009)the Beijing Municipal Science&Technology Commission,Administrative Commission of Zhongguancun Science Park (No. Z211100004821009)。
文摘Active metasurfaces have recently attracted more attention since they can make the light manipulation be versatile and real-time. Metasurfaces-based holography possesses the advantages of high spatial resolution and enormous information capacity for applications in optical displays and encryption. In this work, a tunable polarization multiplexing holographic metasurface controlled by an external magnetic field is proposed. The elaborately designed nanoantennas are arranged on the magneto-optical intermediate layer, which is placed on the metallic reflecting layer. Since the non-diagonal elements of the dielectric tensor of the magneto-optical material become non-zero values once the external magnetic field is applied,the differential absorption for the left and right circularly polarized light can be generated. Meanwhile, the amplitude and phase can be flexibly modulated by changing the sizes of the nanoantennas. Based on this, the dynamic multichannel holographic display of metasurface in the linear and circular polarization channels is realized via magnetic control, and it can provide enhanced security for optical information storage. This work paves the way for the realization of magnetically controllable phase modulation, which is promising in dynamic wavefront control and optical information encryption.
基金Chongqing Social Science Cultivation Project—Empirical Research on the Development of Community-Based Social Organizations'Capacity in the Process of Shifting the Focus of Social Governance to the Grassroots(2021PY21)Chongqing Social Science Planning Project—Research on Collaborative Prevention Mechanisms for Social Risk Governance in Chongqing(2024NDYB105)Chongqing May Day Vocational and Technical College—Research on the Current Status and Pathways of Social Work Participation in Urban and Regional Grassroots Governance(KY2024102).
文摘Community-based social organizations play a vital role in grassroots governance but generally face resource dependence dilemmas that constrain their capacity building and sustainable development.Based on Resource Dependence Theory(RDT),this study addresses the limitations of existing research,such as the lack of an integrated framework and insufficient exploration of bidirectional interaction mechanisms,by systematically analyzing the current state of resource dependence among community-based social organizations.The study constructs a three-dimensional capacity-building strategy:optimizing dependency structures through the establishment of a diversified resource supply network;enhancing resource acquisition capabilities through identification,integration,and utilization of resources;and cultivating organizational autonomy through governance structures,professional competencies,and organizational culture.These strategies provide both theoretical support and practical pathways for community-based social organizations to overcome resource constraints and achieve sustainable development.
