Metalenses—two-dimensionally arranged artificial nanostructures that focus light—have been extensively studied due to their great potential for applications in consumer goods and industrial products.However,when met...Metalenses—two-dimensionally arranged artificial nanostructures that focus light—have been extensively studied due to their great potential for applications in consumer goods and industrial products.However,when metalenses are exposed to harsh environments,they can suffer from mechanical shocks and damage,leading to degradation in optical performance.Here,we present mechanically robust and self-cleanable encapsulated metalenses using spin-on-glass coatings on structured hydrogenated amorphous silicon(a-Si:H),whose optical properties are optimized for effective waveguiding.The atomic structure of a-Si:H has been precisely engineered to achieve a high refractive index(3.23)with near-zero optical losses at the wavelength of 635 nm by adjusting deposition parameters.We develop an analytical model to determine how the refractive index of nanostructures influences light manipulation,highlighting the correlation between refractive indices of structures and metalens efficiencies.Using the high refractive index of the a-Si:H,our encapsulated metalenses achieved a calculated conversion efficiency of 97.2%at the wavelength of 635 nm.Additionally,we verify their mechanical robustness by sonicating encapsulated metalenses with sand for 120 min,demonstrating strong mechanical durability.Furthermore,with the capability of the encapsulated metalenses to perform self-cleaning,this work paves the way for practical applications of metalenses in diverse environments.展开更多
Objective This work is based on analysis on large numbers of coal data such as the latest national coal potential evaluation data and previous data published by REN Deyi, TANG Xiuyi and LU Xukun, and the evaluation m...Objective This work is based on analysis on large numbers of coal data such as the latest national coal potential evaluation data and previous data published by REN Deyi, TANG Xiuyi and LU Xukun, and the evaluation methods of clean potential of coal resources proposed by predecessors. It is found that previous method rank coal is only in accordance with raw coal or washed coal, which fail to take full account of the changes in elements before and after coal washing. Some elements can be removed by washing or other methods, and others may be even enriched after the coal is washed. For this reason, this work defined a new parameter of cleanability and developed its calculation formula to determine the clean potential of coal resources. Cleanability is a comprehensive indicator based on the removal rate of each indicator harmful element in coal. The clean potential of coal is proportional to the value of cleanability. The higher the cleanability value is, the better the clean potential is, and vice versa.展开更多
Particle layers tend to build up on wails in many filtration and separation processes, calling for periodic removal in order to keep the apparatus running. Important factors are the adhesion of the layer on the substr...Particle layers tend to build up on wails in many filtration and separation processes, calling for periodic removal in order to keep the apparatus running. Important factors are the adhesion of the layer on the substrate and the cohesion of the particles in the layer. Models describing such layer detachment generally assume constant and homogeneous conditions for the forces acting on the layer. But in reality detachment is extremely non-stationary concerning place and time, primarily due to changing conditions of the detaching forces on the one hand and changes in the particle layer morphology on the other. This paper describes a model and a simulation based on this model considering such transient kinetic effects, for which some computing results are presented and discussed.展开更多
基金financially supported by the POSCO-POSTECH-RIST Convergence Research Center program funded by POSCOthe National Research Foundation(NRF)grants(RS-2022-NR067559,RS-2024-00462912,RS-2024-00356928,RS-2024-00416272,RS-2024-00337012,RS-2024-00408286,RS-2022-NR068140,RS-2022-NR068141,RS-2021-NR057360)funded by the Ministry of Science and ICT(MSIT)of the Korean government+5 种基金the Korea Evaluation Institute of Industrial Technology(KEIT)grant(No.1415179744/20019169,Alchemist project)funded by the Ministry of Trade,Industry and Energy(MOTIE)of the Korean government.J.S.acknowledges the 3·1 Foundation fellowship.E.L.acknowledges the SBS Foundation fellowshipthe Presidential Science fellowship funded by the MSIT of the Korean governmentthe NRF M.S.fellowship(RS-2024-00464712)funded by the Ministry of Education(MOE)of the Korean governmentthe NRF Ph.D.fellowship(RS-2024-00407755)funded by the MOE of the Korean governmentthe Hyundai Chung Mong-Koo fellowshipthe Presidential Science fellowship funded by the MSIT of the Korean government and the NRF M.S.fellowship(RS-2024-00460406)funded by the MOE of the Korean government。
文摘Metalenses—two-dimensionally arranged artificial nanostructures that focus light—have been extensively studied due to their great potential for applications in consumer goods and industrial products.However,when metalenses are exposed to harsh environments,they can suffer from mechanical shocks and damage,leading to degradation in optical performance.Here,we present mechanically robust and self-cleanable encapsulated metalenses using spin-on-glass coatings on structured hydrogenated amorphous silicon(a-Si:H),whose optical properties are optimized for effective waveguiding.The atomic structure of a-Si:H has been precisely engineered to achieve a high refractive index(3.23)with near-zero optical losses at the wavelength of 635 nm by adjusting deposition parameters.We develop an analytical model to determine how the refractive index of nanostructures influences light manipulation,highlighting the correlation between refractive indices of structures and metalens efficiencies.Using the high refractive index of the a-Si:H,our encapsulated metalenses achieved a calculated conversion efficiency of 97.2%at the wavelength of 635 nm.Additionally,we verify their mechanical robustness by sonicating encapsulated metalenses with sand for 120 min,demonstrating strong mechanical durability.Furthermore,with the capability of the encapsulated metalenses to perform self-cleaning,this work paves the way for practical applications of metalenses in diverse environments.
基金jointly supported by the National Natural Science Foundation of China (grant No.41572146/D0208)
文摘Objective This work is based on analysis on large numbers of coal data such as the latest national coal potential evaluation data and previous data published by REN Deyi, TANG Xiuyi and LU Xukun, and the evaluation methods of clean potential of coal resources proposed by predecessors. It is found that previous method rank coal is only in accordance with raw coal or washed coal, which fail to take full account of the changes in elements before and after coal washing. Some elements can be removed by washing or other methods, and others may be even enriched after the coal is washed. For this reason, this work defined a new parameter of cleanability and developed its calculation formula to determine the clean potential of coal resources. Cleanability is a comprehensive indicator based on the removal rate of each indicator harmful element in coal. The clean potential of coal is proportional to the value of cleanability. The higher the cleanability value is, the better the clean potential is, and vice versa.
基金support by the German Science Foundation (DFG)in the project SCHM 810/27 is acknowledged
文摘Particle layers tend to build up on wails in many filtration and separation processes, calling for periodic removal in order to keep the apparatus running. Important factors are the adhesion of the layer on the substrate and the cohesion of the particles in the layer. Models describing such layer detachment generally assume constant and homogeneous conditions for the forces acting on the layer. But in reality detachment is extremely non-stationary concerning place and time, primarily due to changing conditions of the detaching forces on the one hand and changes in the particle layer morphology on the other. This paper describes a model and a simulation based on this model considering such transient kinetic effects, for which some computing results are presented and discussed.
