In the field of energy conversion,the increasing attention on power electronic equipment is fault detection and diagnosis.A power electronic circuit is an essential part of a power electronic system.The state of its i...In the field of energy conversion,the increasing attention on power electronic equipment is fault detection and diagnosis.A power electronic circuit is an essential part of a power electronic system.The state of its internal components affects the performance of the system.The stability and reliability of an energy system can be improved by studying the fault diagnosis of power electronic circuits.Therefore,an algorithm based on adaptive simulated annealing particle swarm optimization(ASAPSO)was used in the present study to optimize a backpropagation(BP)neural network employed for the online fault diagnosis of a power electronic circuit.We built a circuit simulation model in MATLAB to obtain its DC output voltage.Using Fourier analysis,we extracted fault features.These were normalized as training samples and input to an unoptimized BP neural network and BP neural networks optimized by particle swarm optimization(PSO)and the ASAPSO algorithm.The accuracy of fault diagnosis was compared for the three networks.The simulation results demonstrate that a BP neural network optimized with the ASAPSO algorithm has higher fault diagnosis accuracy,better reliability,and adaptability and can more effectively diagnose and locate faults in power electronic circuits.展开更多
A simple theoretical model based on plasma physics is presented to analyze the microwave plasma effects on the electronic circuits.Results show that under certain parameter conditions the threshold for damaging the el...A simple theoretical model based on plasma physics is presented to analyze the microwave plasma effects on the electronic circuits.Results show that under certain parameter conditions the threshold for damaging the electronic circuits decreases with the decrease of the frequency of the high-power microwave.In addition,the oscillation amplitudes of the plasma electrons increase dramatically when the plasma frequency is near the high-power microwave frequency, which can easily damage the electronic circuits.展开更多
Electronic design automation(EDA)technology is the product of the computer age and finds its foundation in CAD,CAM,CAT,and CAE.EDA is a kind of auxiliary tool in the design process,which requires the designer to carry...Electronic design automation(EDA)technology is the product of the computer age and finds its foundation in CAD,CAM,CAT,and CAE.EDA is a kind of auxiliary tool in the design process,which requires the designer to carry out the file design work using hardware language as the foundation.Subsequently,the computer system automatically compiles and integrates the file to achieve simulation goals,and can complete the programming download of the target chip.At present,this technology is widely used in the communication of electronic circuits.This paper summarizes EDA technology and analyzes its specific application in communication electronic circuits,aiming at promoting the application of CDA technology and promoting the further development of the communication field.展开更多
Supercapacitor has been widely known as a representative electrochemical energy storage device with high power density and long lifespan.Recently,with the deeper understanding of its charge storage mechanism,unidirect...Supercapacitor has been widely known as a representative electrochemical energy storage device with high power density and long lifespan.Recently,with the deeper understanding of its charge storage mechanism,unidirectional-charging supercapacitor,also called supercapacitor diode(CAPode),is successfully developed based on the ion-sieving effect of its working electrode towards electrolyte ions.Because CAPode integrates mobile ion and mobile electron in one hybrid circuit,it has a great potential in the emerging fields of ion/electron coupling logic operations,human–machine interface,neural network interaction,and in vivo diagnosis and treatment.Accordingly,we herein elucidate the working mechanism and design philosophy of CAPode,and summarize the electrode materials that are suitable for constructing CAPode.Meanwhile,some other supercapacitor-based devices beyond CAPode are also introduced,and their potential applications are instructively presented.Finally,we outline the challenges and chances of CAPode-related techniques.展开更多
Dear Editor: There is accumulating evidence that human blood electronic circuit components and their application circuits become more and more important to cyborg implant/engineering, man-machine interface, hu- man ...Dear Editor: There is accumulating evidence that human blood electronic circuit components and their application circuits become more and more important to cyborg implant/engineering, man-machine interface, hu- man disease detection and healing, and artificial brain evolutionusl. Here, we report the first development of human plasma-based amplifier circuit in the dis- crete as well as integrated circuit (IC) configuration mode. Electrolytes in the human blood contain an enormous number of charge carriers such as positive and negative molecule/atom ions, which are electri- cally conducting media and therefore can be utilized for developing electronic circuit components and their application circuits. These electronic circuits obvi- ously have very high application impact potential towards bio-medical engineering and medical science and technology.展开更多
By means of circuit simulation, hardware of electronic control unit (ECU) of high pressure common-rail electronic control fuel system for diesel engine is designed. According to the system requirements for hardware ...By means of circuit simulation, hardware of electronic control unit (ECU) of high pressure common-rail electronic control fuel system for diesel engine is designed. According to the system requirements for hardware of ECU, signal-processing circuit of variable reluctance (VR) sensor, filter circuit for input signal, high voltage power circuit and driver and protection circuit of solenoid are simulated as emphases. Difficulties of wide scope of VR sensor output signal, efficiency of high voltage power and reliable and swift driver of solenoid are solved. The results of simulation show that the hardware meets the requirement of the fuel system. At the same time, circuit simulation can greatly increase quality of the design, alleviate design labor and shorten design time.展开更多
The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit (ECU) design. By means of circuit simulation...The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit (ECU) design. By means of circuit simulation, the thermal design of ECU for electronic unit pump (EUP) fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time展开更多
Printed circuit boards(PCBs)are representative composite materials,and their high-quality drilling machining remains a persistent challenge in the industry.The finishing of the cutting edge of a microdrill is crucial ...Printed circuit boards(PCBs)are representative composite materials,and their high-quality drilling machining remains a persistent challenge in the industry.The finishing of the cutting edge of a microdrill is crucial to drill performance in machining fine-quality holes with a prolonged tool life.The miniature size involving submicron scale geometric dimensions,a complex flute shape,and low fracture toughness makes the cutting edge of microdrills susceptible to breakage and has been the primary limiting factor in edge preparation for microdrills.In this study,a newly developed cutting edge preparation method for microdrills was tested experimentally on electronic printed circuit boards.The proposed method,namely,shear thickening polishing,limited the cutting edge burrs and chipping on the cutting edge,and this in turn transformed the cutting edge’s radius from being sharp to smooth.Moreover,the edge–edge radius could be regulated by adjusting the processing time.PCB drilling experiments were conducted to investigate the influence of different cutting edge radii on wear,hole position accuracy,nail head value,and hole wall roughness.The proposed approach showed 20%enhancement in hole position accuracy,33%reduction in the nail head value,and 19%reduction in hole wall roughness compared with the original microdrill.However,a threshold is needed;without it,excessive shear thickening polishing will result in a blunt edge,which may accelerate the wear of the microdrill.Wear was identified as the primary factor that reduced hole quality.The study indicates that in printed circuit board machining,microdrills should effectively eliminate grinding defects and maintain the sharpness of the cutting edge as much as possible to obtain excellent drilling quality.Overall,shear thickening polishing is a promising method for cutting edge preparation of microdrills.Further research and optimization can lead to additional improvements in microdrill performance and contribute to the continued advancement of printed circuit board manufacturing.展开更多
There is an urgent need for high-quality and high-frequency clock generators for high-energy physics experiments.The transmission data rate exceeds 10 Gbps for a single channel in future readout electronics of silicon...There is an urgent need for high-quality and high-frequency clock generators for high-energy physics experiments.The transmission data rate exceeds 10 Gbps for a single channel in future readout electronics of silicon pixel detectors.Others,such as time measurement detectors,require a high time resolution based on the time-to-digital readout architecture.A phase-locked loop(PLL)is an essential and broadly used circuit in these applications.This study presents an application-specific integrated circuit of a low-jitter,low-power LC-tank that is PLL fabricated using 55-nm CMOS technology.It includes a 3rd-order frequency synthesis loop with a programmable bandwidth,a divide-by-2 pre-scaler,standard low-voltage differential signaling interfaces,and a current mode logic(CML)driver for clock transmissions.All the d-flip-flop dividers and phase-frequency detectors are protected from single-event upsets using the triple modular redundancy technique.The proposed VCO uses low-pass filters to suppress the noise from bias circuits.The tested LC-PLL covers a frequency locking range between 4.74 GHz and 5.92 GHz with two sub-bands.The jitter measurements of the frequency-halved clock(2.56 GHz)are less than 460 fs and 0.8 ps for the random and deterministic jitters,respectively,and a total of 7.5 ps peak-to-peak with a bit error rate of 10^(-12).The random and total jitter values for frequencies of 426 MHz and 20 MHz are less than 1.8 ps and 65 ps,respectively.The LC-PLL consumed 27 mW for the core and 73.8 mW in total.The measured results nearly coincided with the simulations and validated the analyses and tests.展开更多
The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find d...The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find direct applications in the characterization and modeling of the macroscopic electrical properties of the biological media for assessing the effects of fields induced by electromagnetic radiation sources in the human body to set up new standards <span>on the Human exposure to electromagnetic fields. To do this, we have taken into account the different physical phenomena of propagation of a hyper-frequency electromagnetic plane wave and on the other hand, the expe</span>rimental values <span></span><span><span><span style="font-family:;" "="">in order to model the electrical behavior of human biological tissues based on an equivalent electronic circuit model composed of capacities, resistance and reel, which assimilates the biological tissues of the skin, grease, blood. This model using the characteristic impedance of the dielectric support makes it possible to evaluate the voltage induced by the electromagnetic waves of the hyper-frequencies in the studied biological system. The results of the simulations obtained from computer tools demonstrate that the hyper-frequency electromagnetic waves can result in an elevation of the electrical potential of the biological tissues. Despite this potential is a decreasing function of the penetration depth.</span></span></span>展开更多
ZnO whiskers observation on the surface of SnZn/Cu solder joints in concentrator silicon solar cells solder layer is reported. In the experiment,SnZn/Cu samples are left in laboratory after reflow soldering for two ye...ZnO whiskers observation on the surface of SnZn/Cu solder joints in concentrator silicon solar cells solder layer is reported. In the experiment,SnZn/Cu samples are left in laboratory after reflow soldering for two years before an examination by SEM,then ZnO whiskers can be observed obviously,which grows out from the rich-Zn phase of the samples and causes electrical short circuit in the electronics appliances,which demonstrates that the SnZn solder shows a risk for the short circuiting failure of an electronic device. Moreover,the growth mechanism of ZnO whiskers is researched based on cracked oxide theory,which provides the reference support for SnZn solders application.展开更多
This paper introduces a new three dimensional autonomous system with five equilibrium points. It demonstrates complex chaotic behaviours within a wide range of parameters, which are described by phase portraits, Lyapu...This paper introduces a new three dimensional autonomous system with five equilibrium points. It demonstrates complex chaotic behaviours within a wide range of parameters, which are described by phase portraits, Lyapunov exponents, frequency spectrum, etc. Analysis of the bifurcation and Poincar@ map is used to reveal mechanisms of generating these complicated phenomena. The corresponding electronic circuits are designed, exhibiting experimental chaotic attractors in accord with numerical simulations. Since frequency spectrum analysis shows a broad frequency bandwidth, this system has perspective of potential applications in such engineering fields as secure communication.展开更多
High Te superconductor (HTS) technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and ...High Te superconductor (HTS) technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.展开更多
3D printing has opened new horizons for the manufacturing industry in general, and 3D printers have become the tools for technological advancements. There is a huge divide between the pricing of industrial and desktop...3D printing has opened new horizons for the manufacturing industry in general, and 3D printers have become the tools for technological advancements. There is a huge divide between the pricing of industrial and desktop 3D printers with the former being on the expensive side capable of producing excellent quality products and latter being on the low-cost side with moderate quality results. However, there is a larger room for improvements and enhancements for the desktop systems as compared to the industrial ones. In this paper, a desktop 3D printer called Prusa Mendel i2 has been modified and integrated with an additional extruder so that the system can work with dual extruders and produce bespoke electronic circuits. The communication between the two extruders has been established by making use of the In-Chip Serial Program- ming port on the Arduino Uno controlling the printer. The biggest challenge is to control the flow of electric paint (to be dispensed by the new extruder) and CFD (Computa- tional Fluid Dynamics) analysis has been carried out to ascertain the optimal conditions for proper dispensing. The final product is a customised electronic circuit with the base of plastic (from the 3D printer's extruder) and electronic paint (from the additional extruder) properly dispensed to create a live circuit on a plastic platform. This low-cost enhancement to a desktop 3D printer can provide a new prospect to produce multiple material parts where the additional extruder can be filled with any material that can be properly dispensed from its nozzle.展开更多
In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetpri...In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetprinted silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics.展开更多
基金supported by the 2022 Project for Improving the Basic Research Ability of Young and Middle-aged Teachers in Guangxi Universities(Grant No.2022KY0209).
文摘In the field of energy conversion,the increasing attention on power electronic equipment is fault detection and diagnosis.A power electronic circuit is an essential part of a power electronic system.The state of its internal components affects the performance of the system.The stability and reliability of an energy system can be improved by studying the fault diagnosis of power electronic circuits.Therefore,an algorithm based on adaptive simulated annealing particle swarm optimization(ASAPSO)was used in the present study to optimize a backpropagation(BP)neural network employed for the online fault diagnosis of a power electronic circuit.We built a circuit simulation model in MATLAB to obtain its DC output voltage.Using Fourier analysis,we extracted fault features.These were normalized as training samples and input to an unoptimized BP neural network and BP neural networks optimized by particle swarm optimization(PSO)and the ASAPSO algorithm.The accuracy of fault diagnosis was compared for the three networks.The simulation results demonstrate that a BP neural network optimized with the ASAPSO algorithm has higher fault diagnosis accuracy,better reliability,and adaptability and can more effectively diagnose and locate faults in power electronic circuits.
文摘A simple theoretical model based on plasma physics is presented to analyze the microwave plasma effects on the electronic circuits.Results show that under certain parameter conditions the threshold for damaging the electronic circuits decreases with the decrease of the frequency of the high-power microwave.In addition,the oscillation amplitudes of the plasma electrons increase dramatically when the plasma frequency is near the high-power microwave frequency, which can easily damage the electronic circuits.
文摘Electronic design automation(EDA)technology is the product of the computer age and finds its foundation in CAD,CAM,CAT,and CAE.EDA is a kind of auxiliary tool in the design process,which requires the designer to carry out the file design work using hardware language as the foundation.Subsequently,the computer system automatically compiles and integrates the file to achieve simulation goals,and can complete the programming download of the target chip.At present,this technology is widely used in the communication of electronic circuits.This paper summarizes EDA technology and analyzes its specific application in communication electronic circuits,aiming at promoting the application of CDA technology and promoting the further development of the communication field.
基金We acknowledge the financial support from the China Postdoctoral Science Foundation(Grant Nos.BX20220139 and 2021M701530)the National Natural Science Foundation of China(Grant No.61874166)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.lzujbky-2021-sp50)the Science and Technology Program of Qinghai Province(Grant No.2022-ZJ-703).
文摘Supercapacitor has been widely known as a representative electrochemical energy storage device with high power density and long lifespan.Recently,with the deeper understanding of its charge storage mechanism,unidirectional-charging supercapacitor,also called supercapacitor diode(CAPode),is successfully developed based on the ion-sieving effect of its working electrode towards electrolyte ions.Because CAPode integrates mobile ion and mobile electron in one hybrid circuit,it has a great potential in the emerging fields of ion/electron coupling logic operations,human–machine interface,neural network interaction,and in vivo diagnosis and treatment.Accordingly,we herein elucidate the working mechanism and design philosophy of CAPode,and summarize the electrode materials that are suitable for constructing CAPode.Meanwhile,some other supercapacitor-based devices beyond CAPode are also introduced,and their potential applications are instructively presented.Finally,we outline the challenges and chances of CAPode-related techniques.
文摘Dear Editor: There is accumulating evidence that human blood electronic circuit components and their application circuits become more and more important to cyborg implant/engineering, man-machine interface, hu- man disease detection and healing, and artificial brain evolutionusl. Here, we report the first development of human plasma-based amplifier circuit in the dis- crete as well as integrated circuit (IC) configuration mode. Electrolytes in the human blood contain an enormous number of charge carriers such as positive and negative molecule/atom ions, which are electri- cally conducting media and therefore can be utilized for developing electronic circuit components and their application circuits. These electronic circuits obvi- ously have very high application impact potential towards bio-medical engineering and medical science and technology.
文摘By means of circuit simulation, hardware of electronic control unit (ECU) of high pressure common-rail electronic control fuel system for diesel engine is designed. According to the system requirements for hardware of ECU, signal-processing circuit of variable reluctance (VR) sensor, filter circuit for input signal, high voltage power circuit and driver and protection circuit of solenoid are simulated as emphases. Difficulties of wide scope of VR sensor output signal, efficiency of high voltage power and reliable and swift driver of solenoid are solved. The results of simulation show that the hardware meets the requirement of the fuel system. At the same time, circuit simulation can greatly increase quality of the design, alleviate design labor and shorten design time.
文摘The high working junction temperature of power component is the most common reason of its failure. So the thermal design is of vital importance in electronic control unit (ECU) design. By means of circuit simulation, the thermal design of ECU for electronic unit pump (EUP) fuel system is applied. The power dissipation model of each power component in the ECU is created and simulated. According to the analyses of simulation results, the factors which affect the power dissipation of components are analyzed. Then the ways for reducing the power dissipation of power components are carried out. The power dissipation of power components at different engine state is calculated and analyzed. The maximal power dissipation of each power component in all possible engine state is also carried out based on these simulations. A cooling system is designed based on these studies. The tests show that the maximum total power dissipation of ECU drops from 43.2 W to 33.84 W after these simulations and optimizations. These applications of simulations in thermal design of ECU can greatly increase the quality of the design, save the design cost and shorten design time
基金support from the National Natural Science Foundation of China(Grant No.52175441)the Natural Science Foundation of Zhejiang Province,China(Grant No.LD22E050010)+4 种基金the travel scholarship from the China Scholarship Council(Grant No.202208330333)for secondment of Jiahuan Wang at London South Bank University(LSBU)for working closely with Prof.GoelSaurav Goel would like to acknowledge the funding support from UK Research and Innovation,UKRI(Grant Nos.EP/S036180/1 and EP/T024607/1)the feasibility study awards to LSBU from the UKRI National Interdisciplinary Circular Economy Hub(Grant No.EP/V029746/1)Transforming the Foundation Industries:A Network+(Grant No.EP/V026402/1)the International Exchange Cost Share Award by the Royal Society(Grant No.IEC\NSFC\223536).This work accessed the supercomputing service(Isambard-AI,Bristol,UK)via the Resource Allocation Panel and Kittrick(LSBU)-based computational resources.
文摘Printed circuit boards(PCBs)are representative composite materials,and their high-quality drilling machining remains a persistent challenge in the industry.The finishing of the cutting edge of a microdrill is crucial to drill performance in machining fine-quality holes with a prolonged tool life.The miniature size involving submicron scale geometric dimensions,a complex flute shape,and low fracture toughness makes the cutting edge of microdrills susceptible to breakage and has been the primary limiting factor in edge preparation for microdrills.In this study,a newly developed cutting edge preparation method for microdrills was tested experimentally on electronic printed circuit boards.The proposed method,namely,shear thickening polishing,limited the cutting edge burrs and chipping on the cutting edge,and this in turn transformed the cutting edge’s radius from being sharp to smooth.Moreover,the edge–edge radius could be regulated by adjusting the processing time.PCB drilling experiments were conducted to investigate the influence of different cutting edge radii on wear,hole position accuracy,nail head value,and hole wall roughness.The proposed approach showed 20%enhancement in hole position accuracy,33%reduction in the nail head value,and 19%reduction in hole wall roughness compared with the original microdrill.However,a threshold is needed;without it,excessive shear thickening polishing will result in a blunt edge,which may accelerate the wear of the microdrill.Wear was identified as the primary factor that reduced hole quality.The study indicates that in printed circuit board machining,microdrills should effectively eliminate grinding defects and maintain the sharpness of the cutting edge as much as possible to obtain excellent drilling quality.Overall,shear thickening polishing is a promising method for cutting edge preparation of microdrills.Further research and optimization can lead to additional improvements in microdrill performance and contribute to the continued advancement of printed circuit board manufacturing.
基金supported in part by the National Natural Science Foundation of China(Nos.12005245,12075100,and 11775244)by the Scientific and Technological Innovation Project(No.2020000165)from the Institute of High Energy Physics,Chinese Academy of Sciences+1 种基金partially funded by the Scientific Instrument Development Project of the Chinese Academy of Sciences(No.ZDKYYQ20200007)Youth Innovation Promotion Association of the Chinese Academy of Sciences(No.Y201905).
文摘There is an urgent need for high-quality and high-frequency clock generators for high-energy physics experiments.The transmission data rate exceeds 10 Gbps for a single channel in future readout electronics of silicon pixel detectors.Others,such as time measurement detectors,require a high time resolution based on the time-to-digital readout architecture.A phase-locked loop(PLL)is an essential and broadly used circuit in these applications.This study presents an application-specific integrated circuit of a low-jitter,low-power LC-tank that is PLL fabricated using 55-nm CMOS technology.It includes a 3rd-order frequency synthesis loop with a programmable bandwidth,a divide-by-2 pre-scaler,standard low-voltage differential signaling interfaces,and a current mode logic(CML)driver for clock transmissions.All the d-flip-flop dividers and phase-frequency detectors are protected from single-event upsets using the triple modular redundancy technique.The proposed VCO uses low-pass filters to suppress the noise from bias circuits.The tested LC-PLL covers a frequency locking range between 4.74 GHz and 5.92 GHz with two sub-bands.The jitter measurements of the frequency-halved clock(2.56 GHz)are less than 460 fs and 0.8 ps for the random and deterministic jitters,respectively,and a total of 7.5 ps peak-to-peak with a bit error rate of 10^(-12).The random and total jitter values for frequencies of 426 MHz and 20 MHz are less than 1.8 ps and 65 ps,respectively.The LC-PLL consumed 27 mW for the core and 73.8 mW in total.The measured results nearly coincided with the simulations and validated the analyses and tests.
文摘The main objective of this proposed article is to provide explanations to justify the validity of the results of the studies of the interaction between the electromagnetic fields and the human body. It can also find direct applications in the characterization and modeling of the macroscopic electrical properties of the biological media for assessing the effects of fields induced by electromagnetic radiation sources in the human body to set up new standards <span>on the Human exposure to electromagnetic fields. To do this, we have taken into account the different physical phenomena of propagation of a hyper-frequency electromagnetic plane wave and on the other hand, the expe</span>rimental values <span></span><span><span><span style="font-family:;" "="">in order to model the electrical behavior of human biological tissues based on an equivalent electronic circuit model composed of capacities, resistance and reel, which assimilates the biological tissues of the skin, grease, blood. This model using the characteristic impedance of the dielectric support makes it possible to evaluate the voltage induced by the electromagnetic waves of the hyper-frequencies in the studied biological system. The results of the simulations obtained from computer tools demonstrate that the hyper-frequency electromagnetic waves can result in an elevation of the electrical potential of the biological tissues. Despite this potential is a decreasing function of the penetration depth.</span></span></span>
基金Supported by the National Natural Science Foundation of China(No.51475220)State Foundation of Laboratory of Advanced Brazing Filler Metals&Technology(Zhengzhou Research Institute of Mechanical Engineering)(No.SKLABFMT-2015-03)High Level Talent Plan of Jiangsu Normal University(No.YQ2015002)
文摘ZnO whiskers observation on the surface of SnZn/Cu solder joints in concentrator silicon solar cells solder layer is reported. In the experiment,SnZn/Cu samples are left in laboratory after reflow soldering for two years before an examination by SEM,then ZnO whiskers can be observed obviously,which grows out from the rich-Zn phase of the samples and causes electrical short circuit in the electronics appliances,which demonstrates that the SnZn solder shows a risk for the short circuiting failure of an electronic device. Moreover,the growth mechanism of ZnO whiskers is researched based on cracked oxide theory,which provides the reference support for SnZn solders application.
基金supported by the National Natural Science Foundation of China (Grant No. 10771088)Natural Science Foundation of Jiangsu Province,China (Grant No. 2007098)+3 种基金Outstanding Personnel Program in Six Fields of Jiangsu Province,China (Grant No. 6-A-029)National Natural Science (Youth) Foundation of China (Grant No. 10801140)Youth Foundation of Chongqing Normal University,China (Grant No. 08XLQ04)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (Grant No. 09B 202Z)
文摘This paper introduces a new three dimensional autonomous system with five equilibrium points. It demonstrates complex chaotic behaviours within a wide range of parameters, which are described by phase portraits, Lyapunov exponents, frequency spectrum, etc. Analysis of the bifurcation and Poincar@ map is used to reveal mechanisms of generating these complicated phenomena. The corresponding electronic circuits are designed, exhibiting experimental chaotic attractors in accord with numerical simulations. Since frequency spectrum analysis shows a broad frequency bandwidth, this system has perspective of potential applications in such engineering fields as secure communication.
文摘High Te superconductor (HTS) technology has been used to develop a unique high Q resonant circuit. Such circuit or device has some special characteristics such as very high voltage generation. Theoretical study and experimental approaches have proceeded for the concept verification. This paper presents the theory about this high Q resonant circuit. The operation principle of the circuit is described. A practical prototype for HTS high voltage generation is also demonstrated. The experiment result shows that very high voltages can be achieved by the developed method using HTS technology.
文摘3D printing has opened new horizons for the manufacturing industry in general, and 3D printers have become the tools for technological advancements. There is a huge divide between the pricing of industrial and desktop 3D printers with the former being on the expensive side capable of producing excellent quality products and latter being on the low-cost side with moderate quality results. However, there is a larger room for improvements and enhancements for the desktop systems as compared to the industrial ones. In this paper, a desktop 3D printer called Prusa Mendel i2 has been modified and integrated with an additional extruder so that the system can work with dual extruders and produce bespoke electronic circuits. The communication between the two extruders has been established by making use of the In-Chip Serial Program- ming port on the Arduino Uno controlling the printer. The biggest challenge is to control the flow of electric paint (to be dispensed by the new extruder) and CFD (Computa- tional Fluid Dynamics) analysis has been carried out to ascertain the optimal conditions for proper dispensing. The final product is a customised electronic circuit with the base of plastic (from the 3D printer's extruder) and electronic paint (from the additional extruder) properly dispensed to create a live circuit on a plastic platform. This low-cost enhancement to a desktop 3D printer can provide a new prospect to produce multiple material parts where the additional extruder can be filled with any material that can be properly dispensed from its nozzle.
基金supported by the National Key Basic Research Program of China(Nos.2014CB648300,2017YFB0404501)the National Natural Science Foundation of China(Nos.21422402,21674050)+8 种基金the Natural Science Foundation of Jiangsu Province(Nos.BK20140060,BK20130037,BK20140865,BM2012010)the Program for Jiangsu Specially-Appointed Professors(No.RK030STP15001)the Program for New Century Excellent Talents in University(No.NCET-13-0872)the NUPT"1311 Project"and Scientific Foundation(Nos.NY213119,NY213169)the Synergetic Innovation Center for Organic Electronics and Information Displays,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Leading Talent of Technological Innovation of National Ten Thousands Talents Program of Chinathe Excellent Scientific and Technological Innovative Teams of Jiangsu Higher Education Institutions(No.TJ217038)the Program for Graduate Students Research and Innovation of Jiangsu Province(No.KYZZ16-0253)the 333 Project of Jiangsu Province(Nos.BRA2017402,BRA2015374)
文摘In this work, a simple methodology was developed to enhance the patterning resolution of inkjet printing, involving process optimization as well as substrate modification and treatment. The line width of the inkjetprinted silver lines was successfully reduced to 1/3 of the original value using this methodology. Large-area flexible circuits with delicate patterns and good morphology were thus fabricated. The resultant flexible circuits showed excellent electrical conductivity as low as 4.5 Ω/□ and strong tolerance to mechanical bending. The simple methodology is also applicable to substrates with various wettability, which suggests a general strategy to enhance the printing quality of inkjet printing for manufacturing high-performance large-area flexible electronics.