Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temper...Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temperatures.Herein,we design an Fe-Ov-Ce-triggered phase-reversible CeO_(2)−x·Fe·CaO↔CeO_(2)·Ca_(2)Fe_(2)O_(5)oxygen carrier with strong electron-donating ability,which activates CO_(2)at low temperatures and promotes oxygen transformation.Results reveal that the maximum CO_(2)conversion and CO yield obtained with 50 mol%CeO_(2)−x·Fe·CaO are,respectively,426%and 53.6 times higher than those of Fe·CaO at 700℃.This unique multiphase material also retains exceptional redox durability,with no obvious deactivation after 100 splitting cycles.The addition of Ce promotes the formation of the Fe-Ov-Ce structure,which acts as an activator,triggers CO_(2)splitting,and lowers the energy barrier of C═O dissociation.The metallic Fe plays a role in consuming O_(2)−lattice transformed from Fe-Ov-Ce,whereas CaO acts as a structure promoter that enables phase-reversible Fe0↔Fe3+looping.展开更多
Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pr...Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.展开更多
基金supported by the National Key R&D Program of China(2022YFE0105900)the National Natural Science Foundation of China(52436006,52476144,52311530339,42441835)the Innovation-Driven Project of Central South University(2023ZZTS0721).
文摘Advanced oxygen carrier plays a pivotal role in various chemical looping processes,such as CO_(2)splitting.However,oxygen carriers have been restricted by deactivation and inferior oxygen transferability at low temperatures.Herein,we design an Fe-Ov-Ce-triggered phase-reversible CeO_(2)−x·Fe·CaO↔CeO_(2)·Ca_(2)Fe_(2)O_(5)oxygen carrier with strong electron-donating ability,which activates CO_(2)at low temperatures and promotes oxygen transformation.Results reveal that the maximum CO_(2)conversion and CO yield obtained with 50 mol%CeO_(2)−x·Fe·CaO are,respectively,426%and 53.6 times higher than those of Fe·CaO at 700℃.This unique multiphase material also retains exceptional redox durability,with no obvious deactivation after 100 splitting cycles.The addition of Ce promotes the formation of the Fe-Ov-Ce structure,which acts as an activator,triggers CO_(2)splitting,and lowers the energy barrier of C═O dissociation.The metallic Fe plays a role in consuming O_(2)−lattice transformed from Fe-Ov-Ce,whereas CaO acts as a structure promoter that enables phase-reversible Fe0↔Fe3+looping.
基金funded by the National Nature Science Foundation of China(11934009,12174198,and 12227808)the Natural Science Foundation of Jiangsu Province,China(BE2022814)+2 种基金the Universal Technology for Primary and Secondary Schoolsthe National Research Institute for Teaching Materialsthe Qing Lan Project of Jiangsu Province,China。
文摘Acoustic-vortex(AV)tweezers ensure stable particle trapping at a zero-pressure center,while particle assembly between two vortex cores is still prevented by the high-potential barrier.Although a one-dimensional low-pressure attractive path of particle assembly can be constructed by the interference between two independent cylindrical Bessel beams,it remains challenging to create two-dimensional(2D)neighboring vortexes using a source array in practical applications.In this paper,a three-step phase-reversal strategy of 2D particle assembly based on the synchronized evolution of a centrosymmetric array of M off-axis acoustic vortexes(OA-AVs)with a preset radial offset is proposed based on a ring array of planar sources.By introducing initial vortex phase differences of-2π/M and+2π/M to the vortex array,low-pressure patterns of an M-sided regular polygon and M-branched star are formed by connecting the vortex cores and the field center before and after the tangent state of adjacent OA-AVs.Center-oriented particle assembly is finally realized by a central AV constructed by coincident in-phase OA-AVs.The capability of particle manipulation in the lateral and radial directions is demonstrated by low-pressure patterns with acoustic radiation forces pointing to the field center during a synchronized central approach.The field evolution is certified by experimental field measurements for OA-AVs with different vo rtex numbers,initial vortex phase differences,and radial offsets using a ring array of 16 planar sources.The feasibility of particle assembly in two dimensions is also verified by the accurate manipulation of four particles using the low-pressure patterns of a four-sided polygon,a four-branched star,and a central AV in experiments.The three-step strategy paves a new way for 2D particle assembly based on the synchronize d evolution of centrosymmetric OA-AVs using a simplified single-sided source array,exhibiting excellent potential for the precise navigation and manipulation of cells and particles in biomedical applications.
