Multifunctional photodetectors boost the development of traditional optical communication technology and emerging artificial intelligence fields, such as robotics and autonomous driving. However, the current implement...Multifunctional photodetectors boost the development of traditional optical communication technology and emerging artificial intelligence fields, such as robotics and autonomous driving. However, the current implementation of multifunctional detectors is based on the physical combination of optical lenses, gratings, and multiple photodetectors, the large size and its complex structure hinder the miniaturization, lightweight, and integration of devices. In contrast, perovskite materials have achieved remarkable progress in the field of multifunctional photodetectors due to their diverse crystal structures, simple morphology manipulation, and excellent optoelectronic properties. In this review, we first overview the crystal structures and morphology manipulation techniques of perovskite materials and then summarize the working mechanism and performance parameters of multifunctional photodetectors. Furthermore, the fabrication strategies of multifunctional perovskite photodetectors and their advancements are highlighted, including polarized light detection, spectral detection, angle-sensing detection, and selfpowered detection. Finally, the existing problems of multifunctional detectors and the perspectives of their future development are presented.展开更多
Solids in nano-scales hold the promise to exhibit extreme strength and elasticity due to the absence of interior defects and the designability of micro-arrangements.A nano-scaled bulk sample can be produced by diamond...Solids in nano-scales hold the promise to exhibit extreme strength and elasticity due to the absence of interior defects and the designability of micro-arrangements.A nano-scaled bulk sample can be produced by diamond,ice,metallic twins,high entropy alloy(HEA),or cubic boron nitride(cBN).A loading stage capable of 4-DoF movements was designed and built to achieve multi-axial mechanical loading inside a transmission electronic microscope chamber with sub-nanometer loading precision.For single crystal diamond in the shape of nano-needles,we were able to achieve an extreme bending strength of 125 GPa at the tensile side,approaching the theoretical strength of diamond.For ice fibers of sub-micron radius,an extreme elastic strain of 10.9%was acquired,far exceeding the previous record of 0.3%for the elastic strain achievable by ice.For metallic twin specimens made by nano-welding,a shear strain as large as 364%was recorded parallel to the twin boundary.Cyclic shear loading aligned with the twin boundary would drive an up-and-down sweeping movement of the low-angle grain boundary,as composed by an array of dislocations.The sweep of the grain boundary effectively cleanses the lattice defects and creates a feasible scenario of unlimited cyclic endurance.For a HEA dog-bone specimen in nano-scale,an extreme elastic strain of about 10%was achieved.At this level of mechanical straining,stretch-induced melting for crystalline metals,as envisaged by Lindemann a century ago,was realized.For cBN crystals,a fracture path inclined to the stacking hexagon planes would result in a new failure mechanism of layered decohesion,triggered by the extremely large elastic strain(>7%)along the edge of the submicron-scaled specimen.These results indicate ample room for upgrading the mechanical behaviour of solids in nano-scales.展开更多
The fabrication technique of micro/nano-scale speckle patterns with focused ion beam (FIB) system is studied for digital image correlation (DIC) measurement under a scanning electron microscope (SEM).The speckle patte...The fabrication technique of micro/nano-scale speckle patterns with focused ion beam (FIB) system is studied for digital image correlation (DIC) measurement under a scanning electron microscope (SEM).The speckle patterns are fabricated by directly etching the counterpart of the specimen to the black part of a template.Mean intensity gradient is used to evaluate the quality of these SEM images of speckle patterns fabricated based on different templates to select an optimum template.The pattern size depending on the displacement measurement sensitivity is adjusted by altering the magnification of FIB according to the relation curve of the etching size versus magnification.The influencing factors including etching time and ion beam current are discussed.Rigid body translation tests and rotation tests are carried out under SEM to verify the reliability of the fabricated speckle patterns.The calculated values are in good agreement with the imposed ones.展开更多
To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu allo...To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.展开更多
By conducting experimental analyses, including thermal pyrolysis, micro-/nano-CT, argon-ion polishing field emission scanning electron microscopy (FE-SEM), confocal laser scanning microscopy (CLSM), and two-dimensiona...By conducting experimental analyses, including thermal pyrolysis, micro-/nano-CT, argon-ion polishing field emission scanning electron microscopy (FE-SEM), confocal laser scanning microscopy (CLSM), and two-dimensional nuclear magnetic resonance (2D NMR), the Gulong shale oil in the Songliao Basin was investigated with respect to formation model, pore structure and accumulation mechanism. First, in the Gulong shale, there are a large number of pico-algae, nano-algae and dinoflagellates, which were formed in brackish water environment and constituted the hydrogen-rich oil source materials of shale. Second, most of the oil-generating materials of the Qingshankou Formation shale exist in the form of organo-clay complex. During organic matter thermal evolution, clay minerals had double effects of suppression and catalytic hydrogenation, which expanded shale oil window and increased light hydrocarbon yield. Third, the formation of storage space in the Gulong Shale was related to dissolution and hydrocarbon generation. With the diagenesis, micro-/nano-pores increased, pore diameter decreased and more bedding fractures appeared, which jointly gave rise to the unique reservoir with dual media (i.e. nano-scale pores and micro-scale bedding fractures) in the Gulong shale. Fourth, the micro-/nano-scale oil storage unit in the Gulong shale exhibits independent oil/gas occurrence phase, and shows that all-size pores contain oils, which occur in condensate state in micropores or in oil-gas two phase (or liquid) state in macropores/mesopores. The understanding about Gulong shale oil formation and accumulation mechanism has theoretical and practical significance for advancing continental shale oil exploration in China.展开更多
Nanomaterials fabricated via soft lithography has provided many useful tools for biology. The most commonly used material in soft lithography is poly(dimethylsiloxane) (PDMS).
In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a ...In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a uniform external magnetic field up to 1T to examine its influence on structure and morphology of the obtained thin films. Afterwards,each sample was annealed under high magnetic field with strength up to 12 T at 623 K,what allowed compare and determine the changes in morphology and structure,before and after heat treatment.The Co/Ni bi-layered thin films were deposited onto an indium-doped tin oxide(ITO)-coated conducting glass substrate from sulfate baths with boric acid as an additive.The results show drastic changes in the morphology between macro and nano-scaled films which were strongly affected by an introduction of the magnetic field to the electrodeposition process.The annealing process allowed to determine the nucleus transition and showed that under the high temperature treatment it is possible to control the growth mode as well as the phase composition changes.展开更多
The surface topography of a material can influence osteoclast activity.However,the surface structural factors that promote osteoclast activity have not yet been investigated in detail.Therefore,we investigated osteocl...The surface topography of a material can influence osteoclast activity.However,the surface structural factors that promote osteoclast activity have not yet been investigated in detail.Therefore,we investigated osteoclastogenesis by testing various defined patterns with different dimensions and shapes.The systematic patterns,made of a cyclo-olefin polymer,were prepared at a micron-,submicron-,and nano-scale with a groove,hole,or pillar shape with a 1:1 pitch ratio.RAW264.7 cells were cultured on these patterns in the presence of the receptor activator of NF-κB ligand(RANKL).Osteoclast formation was induced in the order:pillar>groove≥hole.The two-dimensional factors also indicated that submicron-sized patterns strongly induced osteoclast formation.The optimal pillar dimension for osteoclast formation was 500 nm in diameter and 2μm in height.Furthermore,we observed two types of characteristic actin structure,i.e.,belt-like structures with small hollow circles and isolated ring-like structures,which formed on or around the pillars depending on size and height.Furthermore,resorption pits were observed mainly on the top of calcium phosphate-coated pillars.Thus,osteoclasts prefer convex shapes,such as pillars for differentiation and resorption.Our results indicate that osteoclastogenesis can be controlled by designing surfaces with specific morphologies.展开更多
基金supported financially by the National Key R&D Program of China (Nos. 2018YFA0208501 and 2018YFA0703200)the National Natural Science Foundation of China (NSFC, Nos. 52103236, 91963212, 21875260)Beijing National Laboratory for Molecular Sciences (No. BNLMSCXXM-202005)。
文摘Multifunctional photodetectors boost the development of traditional optical communication technology and emerging artificial intelligence fields, such as robotics and autonomous driving. However, the current implementation of multifunctional detectors is based on the physical combination of optical lenses, gratings, and multiple photodetectors, the large size and its complex structure hinder the miniaturization, lightweight, and integration of devices. In contrast, perovskite materials have achieved remarkable progress in the field of multifunctional photodetectors due to their diverse crystal structures, simple morphology manipulation, and excellent optoelectronic properties. In this review, we first overview the crystal structures and morphology manipulation techniques of perovskite materials and then summarize the working mechanism and performance parameters of multifunctional photodetectors. Furthermore, the fabrication strategies of multifunctional perovskite photodetectors and their advancements are highlighted, including polarized light detection, spectral detection, angle-sensing detection, and selfpowered detection. Finally, the existing problems of multifunctional detectors and the perspectives of their future development are presented.
文摘Solids in nano-scales hold the promise to exhibit extreme strength and elasticity due to the absence of interior defects and the designability of micro-arrangements.A nano-scaled bulk sample can be produced by diamond,ice,metallic twins,high entropy alloy(HEA),or cubic boron nitride(cBN).A loading stage capable of 4-DoF movements was designed and built to achieve multi-axial mechanical loading inside a transmission electronic microscope chamber with sub-nanometer loading precision.For single crystal diamond in the shape of nano-needles,we were able to achieve an extreme bending strength of 125 GPa at the tensile side,approaching the theoretical strength of diamond.For ice fibers of sub-micron radius,an extreme elastic strain of 10.9%was acquired,far exceeding the previous record of 0.3%for the elastic strain achievable by ice.For metallic twin specimens made by nano-welding,a shear strain as large as 364%was recorded parallel to the twin boundary.Cyclic shear loading aligned with the twin boundary would drive an up-and-down sweeping movement of the low-angle grain boundary,as composed by an array of dislocations.The sweep of the grain boundary effectively cleanses the lattice defects and creates a feasible scenario of unlimited cyclic endurance.For a HEA dog-bone specimen in nano-scale,an extreme elastic strain of about 10%was achieved.At this level of mechanical straining,stretch-induced melting for crystalline metals,as envisaged by Lindemann a century ago,was realized.For cBN crystals,a fracture path inclined to the stacking hexagon planes would result in a new failure mechanism of layered decohesion,triggered by the extremely large elastic strain(>7%)along the edge of the submicron-scaled specimen.These results indicate ample room for upgrading the mechanical behaviour of solids in nano-scales.
基金supported by the National Basic Research Program of China (Grant Nos.2010CB631005 and 2011CB606105)the National Natural Science Foundation of China (Grant Nos.90916010 and 11172151)the Specialized Research Fund for the Doctoral Program of Higher Education (Grant No. 20090002110048)
文摘The fabrication technique of micro/nano-scale speckle patterns with focused ion beam (FIB) system is studied for digital image correlation (DIC) measurement under a scanning electron microscope (SEM).The speckle patterns are fabricated by directly etching the counterpart of the specimen to the black part of a template.Mean intensity gradient is used to evaluate the quality of these SEM images of speckle patterns fabricated based on different templates to select an optimum template.The pattern size depending on the displacement measurement sensitivity is adjusted by altering the magnification of FIB according to the relation curve of the etching size versus magnification.The influencing factors including etching time and ion beam current are discussed.Rigid body translation tests and rotation tests are carried out under SEM to verify the reliability of the fabricated speckle patterns.The calculated values are in good agreement with the imposed ones.
基金Funded by the National Natural Science Foundation of China(No.51905215)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.SJCX23_1233)+1 种基金Major Scientific and Technological Innovation Project of Shandong Province of China(No.2019JZZY020111)the National College Students Innovation and Entrepreneurship Training Program of China(No.CX2022415)。
文摘To improve the comprehensive mechanical properties of Al-Si-Cu alloy,it was treated by a high-pressure torsion process,and the effect of the deformation degree on the microstructure and properties of the Al-Si-Cu alloy was studied.The results show that the reinforcements(β-Si andθ-CuAl_(2)phases)of the Al-Si-Cu alloy are dispersed in theα-Al matrix phase with finer phase size after the treatment.The processed samples exhibit grain sizes in the submicron or even nanometer range,which effectively improves the mechanical properties of the material.The hardness and strength of the deformed alloy are both significantly raised to 268 HV and 390.04 MPa by 10 turns HPT process,and the fracture morphology shows that the material gradually transits from brittle to plastic before and after deformation.The elements interdiffusion at the interface between the phases has also been effectively enhanced.In addition,it is found that the severe plastic deformation at room temperature induces a ternary eutectic reaction,resulting in the formation of ternary Al+Si+CuAl_(2)eutectic.
基金Supported by the Central Guiding Local Science and Technology Development Special Project(ZY20B13)。
文摘By conducting experimental analyses, including thermal pyrolysis, micro-/nano-CT, argon-ion polishing field emission scanning electron microscopy (FE-SEM), confocal laser scanning microscopy (CLSM), and two-dimensional nuclear magnetic resonance (2D NMR), the Gulong shale oil in the Songliao Basin was investigated with respect to formation model, pore structure and accumulation mechanism. First, in the Gulong shale, there are a large number of pico-algae, nano-algae and dinoflagellates, which were formed in brackish water environment and constituted the hydrogen-rich oil source materials of shale. Second, most of the oil-generating materials of the Qingshankou Formation shale exist in the form of organo-clay complex. During organic matter thermal evolution, clay minerals had double effects of suppression and catalytic hydrogenation, which expanded shale oil window and increased light hydrocarbon yield. Third, the formation of storage space in the Gulong Shale was related to dissolution and hydrocarbon generation. With the diagenesis, micro-/nano-pores increased, pore diameter decreased and more bedding fractures appeared, which jointly gave rise to the unique reservoir with dual media (i.e. nano-scale pores and micro-scale bedding fractures) in the Gulong shale. Fourth, the micro-/nano-scale oil storage unit in the Gulong shale exhibits independent oil/gas occurrence phase, and shows that all-size pores contain oils, which occur in condensate state in micropores or in oil-gas two phase (or liquid) state in macropores/mesopores. The understanding about Gulong shale oil formation and accumulation mechanism has theoretical and practical significance for advancing continental shale oil exploration in China.
文摘Nanomaterials fabricated via soft lithography has provided many useful tools for biology. The most commonly used material in soft lithography is poly(dimethylsiloxane) (PDMS).
基金Item Sponsored by National Natural Science Foundation of China(51061130557,51101032)French ANR,Champagne-Ardenne Region Council and Pole MATERALIA(Programme COMAGNET,Grant No.2010-INTB-903-01)
文摘In this study,the possibility of obtaining micro and nano-scaled Co/Ni bi-layered films by use of the electrochemical method was investigated.The electrodeposition process was performed with presence and absence of a uniform external magnetic field up to 1T to examine its influence on structure and morphology of the obtained thin films. Afterwards,each sample was annealed under high magnetic field with strength up to 12 T at 623 K,what allowed compare and determine the changes in morphology and structure,before and after heat treatment.The Co/Ni bi-layered thin films were deposited onto an indium-doped tin oxide(ITO)-coated conducting glass substrate from sulfate baths with boric acid as an additive.The results show drastic changes in the morphology between macro and nano-scaled films which were strongly affected by an introduction of the magnetic field to the electrodeposition process.The annealing process allowed to determine the nucleus transition and showed that under the high temperature treatment it is possible to control the growth mode as well as the phase composition changes.
基金This work was supported by JSPS KAKENHI(Nos.JP25463047,JP18K18984,JP19H03839,and JP19H04461)。
文摘The surface topography of a material can influence osteoclast activity.However,the surface structural factors that promote osteoclast activity have not yet been investigated in detail.Therefore,we investigated osteoclastogenesis by testing various defined patterns with different dimensions and shapes.The systematic patterns,made of a cyclo-olefin polymer,were prepared at a micron-,submicron-,and nano-scale with a groove,hole,or pillar shape with a 1:1 pitch ratio.RAW264.7 cells were cultured on these patterns in the presence of the receptor activator of NF-κB ligand(RANKL).Osteoclast formation was induced in the order:pillar>groove≥hole.The two-dimensional factors also indicated that submicron-sized patterns strongly induced osteoclast formation.The optimal pillar dimension for osteoclast formation was 500 nm in diameter and 2μm in height.Furthermore,we observed two types of characteristic actin structure,i.e.,belt-like structures with small hollow circles and isolated ring-like structures,which formed on or around the pillars depending on size and height.Furthermore,resorption pits were observed mainly on the top of calcium phosphate-coated pillars.Thus,osteoclasts prefer convex shapes,such as pillars for differentiation and resorption.Our results indicate that osteoclastogenesis can be controlled by designing surfaces with specific morphologies.
