MXene is a promising energy storage material for miniaturized microbatteries and microsupercapacitors(MSCs).Despite its superior electrochemical performance,only a few studies have reported MXene-based ultrahigh-rate(...MXene is a promising energy storage material for miniaturized microbatteries and microsupercapacitors(MSCs).Despite its superior electrochemical performance,only a few studies have reported MXene-based ultrahigh-rate(>1000 mV s^(−1))on-paper MSCs,mainly due to the reduced electrical conductance of MXene films deposited on paper.Herein,ultrahigh-rate metal-free on-paper MSCs based on heterogeneous MXene/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)-stack electrodes are fabricated through the combination of direct ink writing and femtosecond laser scribing.With a footprint area of only 20 mm^(2),the on-paper MSCs exhibit excellent high-rate capacitive behavior with an areal capacitance of 5.7 mF cm^(−2)and long cycle life(>95%capacitance retention after 10,000 cycles)at a high scan rate of 1000 mV s^(−1),outperforming most of the present on-paper MSCs.Furthermore,the heterogeneous MXene/PEDOT:PSS electrodes can interconnect individual MSCs into metal-free on-paper MSC arrays,which can also be simultaneously charged/discharged at 1000 mV s^(−1),showing scalable capacitive performance.The heterogeneous MXene/PEDOT:PSS stacks are a promising electrode structure for on-paper MSCs to serve as ultrafast miniaturized energy storage components for emerging paper electronics.展开更多
Supercapacitors,with the merits of both capacitors for safe and fast charge and batteries for high energy storage have drawn tremendous attention.Recently,laser scribed graphene has been increasingly studied for super...Supercapacitors,with the merits of both capacitors for safe and fast charge and batteries for high energy storage have drawn tremendous attention.Recently,laser scribed graphene has been increasingly studied for supercapacitor applications due to its unique properties,such as flexible fabrication,large surface area and high electrical conductivity.With the laser direct writing process,graphene can be directly fabricated and patterned as the supercapacitor electrodes.In this review,facile laser direct writing methods for graphene were firstly summarized.Various precursors,mainly graphene oxide and polyimide were employed for laser scribed graphene and the modifications of graphene properties were also discussed.This laser scribed graphene was applied for electrochemical double-layer capacitors,pseudo-capacitors and hybrid supercapacitors.Diverse strategies including doping,composite materials and pattern design were utilized to enhance the electrochemical performances of supercapacitors.Featured supercapacitors with excellent flexible,ultrafinestructured and integrated functions were also reviewed.展开更多
Increasing both clean water and green energy demands for survival and development are the grand challenges of our age.Here,we successfully fabricate a novel multifunctional 3D graphene-based catalytic membrane(3D-GCM)...Increasing both clean water and green energy demands for survival and development are the grand challenges of our age.Here,we successfully fabricate a novel multifunctional 3D graphene-based catalytic membrane(3D-GCM)with active metal nanoparticles(AMNs)loading for simultaneously obtaining the water purification and clean energy generation,via a“green”one-step laser scribing technology.The as-prepared 3D-GCM shows high porosity and uniform distribution with AMNs,which exhibits high permeated fluxes(over 100 L m^(−2) h^(−1))and versatile super-adsorption capacities for the removal of tricky organic pollutants from wastewater under ultra-low pressure-driving(0.1 bar).After adsorption saturating,the AMNs in 3D-GCM actuates the advanced oxidization process to self-clean the fouled membrane via the catalysis,and restores the adsorption capacity well for the next time membrane separation.Most importantly,the 3D-GCM with the welding of laser scribing overcomes the lateral shear force damaging during the long-term separation.Moreover,the 3D-GCM could emit plentiful of hot electrons from AMNs under light irradiation,realizing the membrane catalytic hydrolysis reactions for hydrogen energy generation.This“green”precision manufacturing with laser scribing technology provides a feasible technology to fabricate high-efficient and robust 3D-GCM microreactor in the tricky wastewater purification and sustainable clean energy production as well.展开更多
The effect of ball scribing on iron loss of conventional grain-oriented ( CGO) and high-permeability grain-oriented ( HGO) electrical steel was investigated. In this paper,ball scribing was achieved by self- designed ...The effect of ball scribing on iron loss of conventional grain-oriented ( CGO) and high-permeability grain-oriented ( HGO) electrical steel was investigated. In this paper,ball scribing was achieved by self- designed ball scribing instrument and a computer-controlled system capable of providing high accuracy and automatic measurements was developed for the magnetisation and measurement at high and low flux densities. The results showed that after ball scribing,iron loss of two types of steel ( C711 and H668 ) apparently decreases ( 5. 5% and 8. 2% respectively after 16mm scribing at 1. 2T) ,and at high and low flux densities, CGO and HGO electrical steel performs differently. Through the formation and development of free magnetic poles and secondary magnetic domains due to compressive stress,primary magnetic domain spacing of grain- oriented electrical steel becomes smaller,which reflects as a reduction of iron loss in the macroscopic magnetic properties. Through iron loss formula derivation,the effect of domain refinement on grain-oriented electrical steel was also interpreted.展开更多
Power loss of Fe-3%Sigrain-oriented silicon steelwas measured after ballscribing with different spacing using a self-designed tool.Three different sections of power loss,including hysteresis loss,abnormalloss,and eddy...Power loss of Fe-3%Sigrain-oriented silicon steelwas measured after ballscribing with different spacing using a self-designed tool.Three different sections of power loss,including hysteresis loss,abnormalloss,and eddy current loss,were measured and calculated,respectively.The loss variation and ratio were analyzed based on the experimentaldata.At 1.0 T,hysteresis loss of tested steelwith scribing spacing of 8 mm descends by 8.2% compared to samples without scribing,which is similar to the totalloss variation,and abnormalloss descends by 16.8%.At 1.0 T,hysteresis loss ratio of the steelwith scribing spacing of 16 mm ascends from 55.7% to 57.9%,and eddy current loss increases from 17.4% to 24.1%,while abnormalloss descends from 26.9% to 23.7%.The experimentalresults show that the reduction of power loss after scribing is mainly due to decreasing of hysteresis loss and abnormalloss.展开更多
In December 2020,the United Nations Educational,Scientific and Cultural Organization(UNESCO)in scribed China's Taijiquan on the Representative List of the In tangible Cultural Heritage of Humanity.
Over the past decade,the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%.The significant efficiency growth and the relative simplification of the technology for obtaini...Over the past decade,the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%.The significant efficiency growth and the relative simplification of the technology for obtaining thin-film solar cells due to liquid printing methods determine the high potential for the low-cost perovskite solar cells manufacturing.However,efficient use of cell geometry is comparable to the size of standard crystalline-Si wafers(156:156 mm and more).Therefore,modular geometry similar to amorphous-Si solar cell approaches is used to scale perovskite solar cells.Serial electrical connection of thin-film cells requires precise processing of the conductive layers that form the device p-i-n structure.The subject of research is the development of a full pulsed laser scribing cycle for inverted perovskite solar cells.In this work,we propose a study of a laser-patterning technology In_(2)O_(3):SnO_(2)(ITO)conductive layer and a photoactive perovskite layer Cs0,2(CH(NH_(2))_(2))_(0,8)PbI_(3).Process regimes of transparent conducting electrodes based on ITO and halide perovskite layer Cs_(0,2)(CH(NH_(2))_(2))_(0,8)PbI_(3)laser patterning were obtained.The optimal parameters for the multipass mode processing of ITO and perovskite layer were determined.The cell was electrically isolated at a scribe line width of 30μm.展开更多
Wedge-shaped microstructures have the ability to reproduce the excellent adhesive properties of geckos’feet because of their unique anisotropic structure.In particular,the controllability of the wedge-shaped microstr...Wedge-shaped microstructures have the ability to reproduce the excellent adhesive properties of geckos’feet because of their unique anisotropic structure.In particular,the controllability of the wedge-shaped microstructures on adhesion is beneficial to the undisturbed grasp or the capture of space targets.However,the problem currently remains of how to process it efficiently and with high quality.Here a strategy called ultraprecision multistep and layered scribing is proposed for the manufacture of the biomimetic controllable adhesive surface.The results show that the metal master mold prepared based on the manufacturing strategy has not only good surface topography but also high reliability and durability.Furthermore,the controllable adhesive surface of 1.96 cm2,fabricated by the proposed manufacturing strategy,has a normal adhesion of 1.012 N,and the corresponding shear friction and adhesion coefficient are 3.105 N and 4.82,respectively.Additionally,the controllable adhesive surface has been shown to be approximately superhydrophobic and also to possess the properties of controllable adhesion and dynamic adhesion.Also,after 250 adhesion-detachment cycles,the normal adhesion and shear friction only decrease by 5%and 3%,respectively.The research realizes an environmentally friendly and efficient method by which to manufacture a durable metal mold for fabricating a biomimetic controllable adhesive surface,laying a foundation for its effective application in the adherence of space-floating targets.展开更多
Effect of ball scribing on magnetic Barkhausen noise (MBN) of conventional grain-oriented (CGO) and high- permeability grain-oriented (HGO) electrical steel was investigated. The results showed that after ball s...Effect of ball scribing on magnetic Barkhausen noise (MBN) of conventional grain-oriented (CGO) and high- permeability grain-oriented (HGO) electrical steel was investigated. The results showed that after ball scribing, root mean square of MBN (MBNrms) of CGO electrical steel increased 9.8% with 4 mm scribing spacing at 1.2 T, and that of HGO electrical steel apparently decreased 17.3% with 16 mm scribing spacing at 1.2 T. Through the formation and development of free magnetic poles and secondary magnetic domains due to compressive stress, primary magnetic domain space of grain-oriented electrical steel becomes smaller, which reflects as a variation of MBN in the macroscopic magnetic properties. Through correlation formula derivation of MBNrms and equilibrium distance between domain walls, effect of domain refinement on grain-oriented electrical steel was also interpreted, and optimum equilibrium distance between domain walls was determined.展开更多
Efect of ball scribing on relative permeability of conventional grain-oriented(CGO) and high permeability grain-oriented(HGO) electrical steel was investigated. The samples were scribed with spacing of 2 mm, 4 mm,...Efect of ball scribing on relative permeability of conventional grain-oriented(CGO) and high permeability grain-oriented(HGO) electrical steel was investigated. The samples were scribed with spacing of 2 mm, 4 mm, 8 mm and 16 mm. The results show that after ball scribing with 16 mm width at 1.0 T, relative permeability of both℃GO and HGO steels was increased by 109% and 80%, respectively. Relative permeability rises as the scribing space increases, with the movement of the peak value of relative permeability to a higher flux density. Relational models describing relative permeability and flux density were constructed with high accuracy based on experimental data. The experimental data curves were analyzed during the magnetizing process.展开更多
Friction stir welding [FSW) has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys. Conventional FSW, however, has not been entirely successful in the joi...Friction stir welding [FSW) has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys. Conventional FSW, however, has not been entirely successful in the joining, processing and manufacturing of different desired materials essential to meet the sophis- ticated green globe requirements. Through the efforts of improving the process and transferring the existing friction stir knowledge base to other advanced applications, several friction stir based daughter technologies have emerged over the timeline, A few among these technologies are well developed while others are under the process of emergence. Beginning with a broad classification of the scattered fric- tions stir based technologies into two categories, welding and processing, it appears now time to know, compile and review these to enable their rapid access for reference and academia. In this review article, the friction stir based technologies classified under the categol^J of welding are those applied for join- ing of materials while the remnant are labeled as friction stir processing (FSP) technologies. This review article presents an overview of four general aspects of both the developed and the developing friction stir based technologies, their associated process parameters, metallurgical features of their products and their feasibility and application to various materials. The lesser known and emerging technologies have been emphasized.展开更多
Humidity sensors have been widely applied to detect environment humidity in various fields. However, most of humidity sensors cannot provide performance needed for high sensitivity and fast response. We report one typ...Humidity sensors have been widely applied to detect environment humidity in various fields. However, most of humidity sensors cannot provide performance needed for high sensitivity and fast response. We report one type of capacitive-type humidity sensors composed of laser-scribed graphene(LSG) as sensing electrodes and graphene oxide/tin dioxide(GO/SnO2) as a sensing layer. The LSG is reduced graphene oxide(rGO) electrodes resulted from selective reducing of GO within a GO/SnO2 composite layer by laser scribing method, and the sensing layer is the un-scribed GO/SnO2 composite. The sensor fabrication is a one-step process which is facile and cost-efficient. When a mass ratio of GO:SnO2 in the composite reaches 1:1, the humidity sensor(named as LSG-GS1) has the best properties than other ratios, which exhibits high sensitivity in the range of 11%~97% relative humidity(RH). In addition, the LSG-GS1 also has very quick response/recovery time(20 s for adsorption and 18 s for desorption) when RH changes from 23% to 84%, and very good stability after monitoring for 41 days. Such excellent performances of the humidity sensor can be attributed to synergistic effect of SnO2 and GO within the composite layer.展开更多
The Legal Inscription of Mose was carved on the north and south walls of the tomb-chapel of the treasury-scribe Mose located in Saqqara, and Mose was a treasury-scribe of the Temple of Ptah in Memphis. The inscription...The Legal Inscription of Mose was carved on the north and south walls of the tomb-chapel of the treasury-scribe Mose located in Saqqara, and Mose was a treasury-scribe of the Temple of Ptah in Memphis. The inscription mainly deals with a lawsuit concerning the land of Mose family between Mose and his opponent, the agent Khay, as well as the four previous land lawsuits mentioned in their testimonies. This document, which is the most important document in the research of the ancient Egyptian legal system, details the entire process of land disputes within the Mose family, including the bringing of a lawsuit, collection of evidence, debate before the court and execution of judgments. In addition, this document is of high academic value to our study of the tax system, land occupation and official corruption in ancient Egypt.展开更多
To hear people talk, there are "black holes" all around us: the U. S.deficit, the Russian economy, the residence of Japan’s Prime Minister.They are found wherever things seem to disappear without leaving a ...To hear people talk, there are "black holes" all around us: the U. S.deficit, the Russian economy, the residence of Japan’s Prime Minister.They are found wherever things seem to disappear without leaving a trace.Ever since Princeton physicist John Wheeler coined the term in 1967 to de-scribe an object whose gravily is so powerful that it swallows everythingaround it even light-this bizarre concept, which first emerged from E-展开更多
基金China Scholarship Council,Grant/Award Number:201906230359Vetenskapsrådet,Grant/Award Number:2019-04731+4 种基金HORIZON EUROPE Digital,Industry and Space,Grant/Award Number:101070255Stiftelsen Olle Engkvist Byggmästare,Grant/Award Number:2014/799Swedish National Infrastructure in Advanced Electron Microscopy,Grant/Award Numbers:2021-00171,RIF21-0026KTH Energy Platform,Grant/Award Number:HT2021Swedish Foundation for Strategic Research,Grant/Award Number:STP19-0014。
文摘MXene is a promising energy storage material for miniaturized microbatteries and microsupercapacitors(MSCs).Despite its superior electrochemical performance,only a few studies have reported MXene-based ultrahigh-rate(>1000 mV s^(−1))on-paper MSCs,mainly due to the reduced electrical conductance of MXene films deposited on paper.Herein,ultrahigh-rate metal-free on-paper MSCs based on heterogeneous MXene/poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)(PEDOT:PSS)-stack electrodes are fabricated through the combination of direct ink writing and femtosecond laser scribing.With a footprint area of only 20 mm^(2),the on-paper MSCs exhibit excellent high-rate capacitive behavior with an areal capacitance of 5.7 mF cm^(−2)and long cycle life(>95%capacitance retention after 10,000 cycles)at a high scan rate of 1000 mV s^(−1),outperforming most of the present on-paper MSCs.Furthermore,the heterogeneous MXene/PEDOT:PSS electrodes can interconnect individual MSCs into metal-free on-paper MSC arrays,which can also be simultaneously charged/discharged at 1000 mV s^(−1),showing scalable capacitive performance.The heterogeneous MXene/PEDOT:PSS stacks are a promising electrode structure for on-paper MSCs to serve as ultrafast miniaturized energy storage components for emerging paper electronics.
基金the funding support of Zhangjiang National Innovation Demonstration Zone(ZJ2019-ZD-005)the support from National Natural Science Foundation of China(Grant No.11974247)the support of Shanghai Super Postdoctoral Incentive Programand and China Postdoctoral Science Foundation(No.2021M692137)。
文摘Supercapacitors,with the merits of both capacitors for safe and fast charge and batteries for high energy storage have drawn tremendous attention.Recently,laser scribed graphene has been increasingly studied for supercapacitor applications due to its unique properties,such as flexible fabrication,large surface area and high electrical conductivity.With the laser direct writing process,graphene can be directly fabricated and patterned as the supercapacitor electrodes.In this review,facile laser direct writing methods for graphene were firstly summarized.Various precursors,mainly graphene oxide and polyimide were employed for laser scribed graphene and the modifications of graphene properties were also discussed.This laser scribed graphene was applied for electrochemical double-layer capacitors,pseudo-capacitors and hybrid supercapacitors.Diverse strategies including doping,composite materials and pattern design were utilized to enhance the electrochemical performances of supercapacitors.Featured supercapacitors with excellent flexible,ultrafinestructured and integrated functions were also reviewed.
基金supported by the National Scientific Foundation of China(No.61974050,61704061,51805184,61974049)Key Laboratory of Non-ferrous Metals and New Materials Processing Technology of Ministry of Education/Guangxi Key Laboratory of Optoelectronic Materials and Devices open Fund(20KF-9)+2 种基金the Natural Science Foundation of Hunan Province of China(No.2018TP2003)Excellent youth project of Hunan Provincial Department of Education(No.18B111)State Key Laboratory of Crop Germplasm Innovation and Resource Utilization(No.17KFXN02).The authors thank the technical support from Analytical and Testing Center at Huazhong University of Science and Technology.
文摘Increasing both clean water and green energy demands for survival and development are the grand challenges of our age.Here,we successfully fabricate a novel multifunctional 3D graphene-based catalytic membrane(3D-GCM)with active metal nanoparticles(AMNs)loading for simultaneously obtaining the water purification and clean energy generation,via a“green”one-step laser scribing technology.The as-prepared 3D-GCM shows high porosity and uniform distribution with AMNs,which exhibits high permeated fluxes(over 100 L m^(−2) h^(−1))and versatile super-adsorption capacities for the removal of tricky organic pollutants from wastewater under ultra-low pressure-driving(0.1 bar).After adsorption saturating,the AMNs in 3D-GCM actuates the advanced oxidization process to self-clean the fouled membrane via the catalysis,and restores the adsorption capacity well for the next time membrane separation.Most importantly,the 3D-GCM with the welding of laser scribing overcomes the lateral shear force damaging during the long-term separation.Moreover,the 3D-GCM could emit plentiful of hot electrons from AMNs under light irradiation,realizing the membrane catalytic hydrolysis reactions for hydrogen energy generation.This“green”precision manufacturing with laser scribing technology provides a feasible technology to fabricate high-efficient and robust 3D-GCM microreactor in the tricky wastewater purification and sustainable clean energy production as well.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 51174057 and 51274062)National High Technology Research and Development Program (Grant No. 2012AA03A503)
文摘The effect of ball scribing on iron loss of conventional grain-oriented ( CGO) and high-permeability grain-oriented ( HGO) electrical steel was investigated. In this paper,ball scribing was achieved by self- designed ball scribing instrument and a computer-controlled system capable of providing high accuracy and automatic measurements was developed for the magnetisation and measurement at high and low flux densities. The results showed that after ball scribing,iron loss of two types of steel ( C711 and H668 ) apparently decreases ( 5. 5% and 8. 2% respectively after 16mm scribing at 1. 2T) ,and at high and low flux densities, CGO and HGO electrical steel performs differently. Through the formation and development of free magnetic poles and secondary magnetic domains due to compressive stress,primary magnetic domain spacing of grain- oriented electrical steel becomes smaller,which reflects as a reduction of iron loss in the macroscopic magnetic properties. Through iron loss formula derivation,the effect of domain refinement on grain-oriented electrical steel was also interpreted.
基金Funded by the National Natural Science Foundation of China(Nos.51174057 and 51404159)the National High Technology Research and Development Program(No.2012AA03A503)Research Fund for the Doctoral Program of Higher Education of China(No.20130042110040)
文摘Power loss of Fe-3%Sigrain-oriented silicon steelwas measured after ballscribing with different spacing using a self-designed tool.Three different sections of power loss,including hysteresis loss,abnormalloss,and eddy current loss,were measured and calculated,respectively.The loss variation and ratio were analyzed based on the experimentaldata.At 1.0 T,hysteresis loss of tested steelwith scribing spacing of 8 mm descends by 8.2% compared to samples without scribing,which is similar to the totalloss variation,and abnormalloss descends by 16.8%.At 1.0 T,hysteresis loss ratio of the steelwith scribing spacing of 16 mm ascends from 55.7% to 57.9%,and eddy current loss increases from 17.4% to 24.1%,while abnormalloss descends from 26.9% to 23.7%.The experimentalresults show that the reduction of power loss after scribing is mainly due to decreasing of hysteresis loss and abnormalloss.
文摘In December 2020,the United Nations Educational,Scientific and Cultural Organization(UNESCO)in scribed China's Taijiquan on the Representative List of the In tangible Cultural Heritage of Humanity.
基金support from the Ministry of Science and Higher Education of the Russian Federation in the framework of the Russian Science Foundation Grant No.21-19-00853R.I.,P.G.and A.I.acknowledge the financial support of“Theoretical and methodological framework for digital transformation in radiology”,(USIS No.123031400118-0)in accordance with the Order No.1196 dated December 21,2022"On approval of state assignments funded by means of allocations from the budget of the city of Moscow to the state budgetary(autonomous)institutions subordinate to the Moscow Health Care Department,for 2023 and the planned period of 2024 and 2025"issued by the Moscow Health Care Department.
文摘Over the past decade,the power conversion efficiency of halide perovskite solar cells has shown a rapid increase to 26.1%.The significant efficiency growth and the relative simplification of the technology for obtaining thin-film solar cells due to liquid printing methods determine the high potential for the low-cost perovskite solar cells manufacturing.However,efficient use of cell geometry is comparable to the size of standard crystalline-Si wafers(156:156 mm and more).Therefore,modular geometry similar to amorphous-Si solar cell approaches is used to scale perovskite solar cells.Serial electrical connection of thin-film cells requires precise processing of the conductive layers that form the device p-i-n structure.The subject of research is the development of a full pulsed laser scribing cycle for inverted perovskite solar cells.In this work,we propose a study of a laser-patterning technology In_(2)O_(3):SnO_(2)(ITO)conductive layer and a photoactive perovskite layer Cs0,2(CH(NH_(2))_(2))_(0,8)PbI_(3).Process regimes of transparent conducting electrodes based on ITO and halide perovskite layer Cs_(0,2)(CH(NH_(2))_(2))_(0,8)PbI_(3)laser patterning were obtained.The optimal parameters for the multipass mode processing of ITO and perovskite layer were determined.The cell was electrically isolated at a scribe line width of 30μm.
基金supported by the Major Research Plan of the National Natural Science Foundation of China(Grant No.91848202)。
文摘Wedge-shaped microstructures have the ability to reproduce the excellent adhesive properties of geckos’feet because of their unique anisotropic structure.In particular,the controllability of the wedge-shaped microstructures on adhesion is beneficial to the undisturbed grasp or the capture of space targets.However,the problem currently remains of how to process it efficiently and with high quality.Here a strategy called ultraprecision multistep and layered scribing is proposed for the manufacture of the biomimetic controllable adhesive surface.The results show that the metal master mold prepared based on the manufacturing strategy has not only good surface topography but also high reliability and durability.Furthermore,the controllable adhesive surface of 1.96 cm2,fabricated by the proposed manufacturing strategy,has a normal adhesion of 1.012 N,and the corresponding shear friction and adhesion coefficient are 3.105 N and 4.82,respectively.Additionally,the controllable adhesive surface has been shown to be approximately superhydrophobic and also to possess the properties of controllable adhesion and dynamic adhesion.Also,after 250 adhesion-detachment cycles,the normal adhesion and shear friction only decrease by 5%and 3%,respectively.The research realizes an environmentally friendly and efficient method by which to manufacture a durable metal mold for fabricating a biomimetic controllable adhesive surface,laying a foundation for its effective application in the adherence of space-floating targets.
基金The financial support of the National Natural Science Foundation of China(Nos.51174057 and 51274062)the National High Technology Research and Development Program (No.2012AA03A503)
文摘Effect of ball scribing on magnetic Barkhausen noise (MBN) of conventional grain-oriented (CGO) and high- permeability grain-oriented (HGO) electrical steel was investigated. The results showed that after ball scribing, root mean square of MBN (MBNrms) of CGO electrical steel increased 9.8% with 4 mm scribing spacing at 1.2 T, and that of HGO electrical steel apparently decreased 17.3% with 16 mm scribing spacing at 1.2 T. Through the formation and development of free magnetic poles and secondary magnetic domains due to compressive stress, primary magnetic domain space of grain-oriented electrical steel becomes smaller, which reflects as a variation of MBN in the macroscopic magnetic properties. Through correlation formula derivation of MBNrms and equilibrium distance between domain walls, effect of domain refinement on grain-oriented electrical steel was also interpreted, and optimum equilibrium distance between domain walls was determined.
基金supported by National Natural Science Foundation of China (Nos. 51174057 and 51274062)the National High Technology Research and Development Program (No. 2012AA03A503)
文摘Efect of ball scribing on relative permeability of conventional grain-oriented(CGO) and high permeability grain-oriented(HGO) electrical steel was investigated. The samples were scribed with spacing of 2 mm, 4 mm, 8 mm and 16 mm. The results show that after ball scribing with 16 mm width at 1.0 T, relative permeability of both℃GO and HGO steels was increased by 109% and 80%, respectively. Relative permeability rises as the scribing space increases, with the movement of the peak value of relative permeability to a higher flux density. Relational models describing relative permeability and flux density were constructed with high accuracy based on experimental data. The experimental data curves were analyzed during the magnetizing process.
基金financial support on this work from the National Natural Science Foundation of China(Grant Nos.51475272 and 51550110501)Shandong University for the Postdoctoral fellowship
文摘Friction stir welding [FSW) has achieved remarkable success in the joining and processing of aluminium alloys and other softer structural alloys. Conventional FSW, however, has not been entirely successful in the joining, processing and manufacturing of different desired materials essential to meet the sophis- ticated green globe requirements. Through the efforts of improving the process and transferring the existing friction stir knowledge base to other advanced applications, several friction stir based daughter technologies have emerged over the timeline, A few among these technologies are well developed while others are under the process of emergence. Beginning with a broad classification of the scattered fric- tions stir based technologies into two categories, welding and processing, it appears now time to know, compile and review these to enable their rapid access for reference and academia. In this review article, the friction stir based technologies classified under the categol^J of welding are those applied for join- ing of materials while the remnant are labeled as friction stir processing (FSP) technologies. This review article presents an overview of four general aspects of both the developed and the developing friction stir based technologies, their associated process parameters, metallurgical features of their products and their feasibility and application to various materials. The lesser known and emerging technologies have been emphasized.
基金supported by the Fujian Provincial Department of Science and Technology (No. 2018H0041,2018H0042,2018T3010,2019T3017 and 2019T3024)。
文摘Humidity sensors have been widely applied to detect environment humidity in various fields. However, most of humidity sensors cannot provide performance needed for high sensitivity and fast response. We report one type of capacitive-type humidity sensors composed of laser-scribed graphene(LSG) as sensing electrodes and graphene oxide/tin dioxide(GO/SnO2) as a sensing layer. The LSG is reduced graphene oxide(rGO) electrodes resulted from selective reducing of GO within a GO/SnO2 composite layer by laser scribing method, and the sensing layer is the un-scribed GO/SnO2 composite. The sensor fabrication is a one-step process which is facile and cost-efficient. When a mass ratio of GO:SnO2 in the composite reaches 1:1, the humidity sensor(named as LSG-GS1) has the best properties than other ratios, which exhibits high sensitivity in the range of 11%~97% relative humidity(RH). In addition, the LSG-GS1 also has very quick response/recovery time(20 s for adsorption and 18 s for desorption) when RH changes from 23% to 84%, and very good stability after monitoring for 41 days. Such excellent performances of the humidity sensor can be attributed to synergistic effect of SnO2 and GO within the composite layer.
文摘The Legal Inscription of Mose was carved on the north and south walls of the tomb-chapel of the treasury-scribe Mose located in Saqqara, and Mose was a treasury-scribe of the Temple of Ptah in Memphis. The inscription mainly deals with a lawsuit concerning the land of Mose family between Mose and his opponent, the agent Khay, as well as the four previous land lawsuits mentioned in their testimonies. This document, which is the most important document in the research of the ancient Egyptian legal system, details the entire process of land disputes within the Mose family, including the bringing of a lawsuit, collection of evidence, debate before the court and execution of judgments. In addition, this document is of high academic value to our study of the tax system, land occupation and official corruption in ancient Egypt.
文摘To hear people talk, there are "black holes" all around us: the U. S.deficit, the Russian economy, the residence of Japan’s Prime Minister.They are found wherever things seem to disappear without leaving a trace.Ever since Princeton physicist John Wheeler coined the term in 1967 to de-scribe an object whose gravily is so powerful that it swallows everythingaround it even light-this bizarre concept, which first emerged from E-