Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic partic...Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic particles, such as heavy ions, protons, and alpha particles, can induce single event effects(SEEs) that lead CNNs to malfunction and can significantly impact the reliability of a CNN system. In this paper, the MNIST CNN system was constructed based on a 28 nm systemon-chip(SoC), and then an alpha particle irradiation experiment and fault injection were applied to evaluate the SEE of the CNN system. Various types of soft errors in the CNN system have been detected, and the SEE cross sections have been calculated. Furthermore, the mechanisms behind some soft errors have been explained. This research will provide technical support for the design of radiation-resistant artificial intelligence chips.展开更多
A DC regulated power supply with numerical control based on single chip microcomputer (SCM) is designed. SCM is the main controller and output voltage o{ DC power supply can be set by keyboard. The analog voltage ca...A DC regulated power supply with numerical control based on single chip microcomputer (SCM) is designed. SCM is the main controller and output voltage o{ DC power supply can be set by keyboard. The analog voltage can be obtained through D/A converter (DAC0832) so that different voltages can be provided by operational amplifier. The output voltage varies from 0 V to 12 V with the incremental value of 0. 1 V. The actual output voltage is shown in the nixietube. This DC regulated power supply is characterized by simple structure and easy operation.展开更多
With principles of reliability, independence, practicality and economical effi- ciency, a set of intelligent fire alarm system based on AVRmega128 single chip microcomputer was designed to solve problems of fire alarm...With principles of reliability, independence, practicality and economical effi- ciency, a set of intelligent fire alarm system based on AVRmega128 single chip microcomputer was designed to solve problems of fire alarm system in many large- scale warehouses. Using advanced flame sensor, 485 bus communication, computer interactive software and related peripheral devices, this intelligent fire alarm system has functions of sound-light alarm and intelligent fire extinguishing. The human-com- puter interactive software was adopted for the remote control of the alarm main control panel through the 485 bus communication. This design of intelligent fire alarm system shows high reference and practical value to the development of intel- ligent alarm products with high integration and high reliability.展开更多
Developed a new program structure using in single chip computer system, which based on multitasking mechanism. Discussed the specific method for realization of the new structure. The applied sample is also provided.
Presents a one grade adaptive controller with one reference model which is built according to δ MRACS adaptive control theory and used to control an actual high order hydraulic system, and the whole hardware system u...Presents a one grade adaptive controller with one reference model which is built according to δ MRACS adaptive control theory and used to control an actual high order hydraulic system, and the whole hardware system used, which includes a AT89C51 single chip microcomputer, 74Ls373 flip latch, 6116 store, eight bit ADC0809, and so on, and the satisfactory results obtained in study on hydraulic control system.展开更多
Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,r...Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,respectively.Single-bit upset and multicell upset events were observed,and an uppermost number of nine upset cells were discovered in the 90 MeV proton irradiation test.The results indicate that the SEE sensitivities of the 28 nm SoC to the 90 MeV and 70 MeV protons were similar.Cosmic Ray Effects on Micro-Electronics Monte Carlo simulations were analyzed,and it demonstrates that protons can induce effects in a 28 nm SoC if their energies are greater than 1.4 MeV and that the lowest corresponding linear energy transfer was 0.142 MeV cm^2 mg^-1.The similarities and discrepancies of the SEEs induced by the 90 MeV and 70 MeV protons were analyzed.展开更多
EGFR mutations companion diagnostics have been proved to be crucial for the efficacy of tyrosine kinase inhibitor targeted cancer therapies. To uncover multiple mutations occurred in minority of EGFR-mutated cells,whi...EGFR mutations companion diagnostics have been proved to be crucial for the efficacy of tyrosine kinase inhibitor targeted cancer therapies. To uncover multiple mutations occurred in minority of EGFR-mutated cells,which may be covered by the noises from majority of unmutated cells, is currently becoming an urgent clinical requirement. Here we present the validation of a microfluidic-chip-based method for detecting EGFR multimutations at single-cell level. By trapping and immunofluorescently imaging single cells in specifically designed silicon microwells, the EGFR-expressed cellswere easily identified. By in situ lysing single cells, the cell lysates of EGFR-expressed cells were retrieved without cross-contamination. Benefited from excluding the noise from cells without EGFR expression, the simple and cost-effective Sanger's sequencing, but not the expensive deep sequencing of the whole cell population, was used to discover multi-mutations. We verified the new method with precisely discovering three most important EGFR drugrelated mutations from a sample in which EGFR-mutated cells only account for a small percentage of whole cell population. The microfluidic chip is capable of discovering not only the existence of specific EGFR multi-mutations,but also other valuable single-cell-level information: on which specific cells the mutations occurred, or whether different mutations coexist on the same cells. This microfluidic chip constitutes a promising method to promote simple and cost-effective Sanger's sequencing to be a routine test before performing targeted cancer therapy.展开更多
This paper introduces a SF vector control system of a slip frequency controlled induction mo-tor with simple structure,fair performance and convenient operation.It is realized by two singlechip microprocessors and fed...This paper introduces a SF vector control system of a slip frequency controlled induction mo-tor with simple structure,fair performance and convenient operation.It is realized by two singlechip microprocessors and fed from SPWM-GTR inverter.The whole system is combined by twosubsystems,both of them are 8031 single chip microprocessors.The communication between themis coordinated by the full duplex serial port within the chip and ask-and-answer communicationmanner.The error-corrected means adopted has improved the operation reliability of the system.A series of experimental results on a 3 kW induction motor are given at the end of this paper.展开更多
A single molecule detection technique was developed by the combination of a single channel poly (dimethylsiloxane)/glass micro-fluidic chip and fluorescence correlation spectroscopy (FCS). This method was successf...A single molecule detection technique was developed by the combination of a single channel poly (dimethylsiloxane)/glass micro-fluidic chip and fluorescence correlation spectroscopy (FCS). This method was successfully used to determine the proportion of two model components in the mixture containing fluorescein and the rhodamine-green succinimidyl ester.展开更多
Taking a specific production process as an example, this paper introduces the design of multi slot and unequal temperature PID controller based on single chip microcomputer. The mathematical implementation method...Taking a specific production process as an example, this paper introduces the design of multi slot and unequal temperature PID controller based on single chip microcomputer. The mathematical implementation method of PID algorithm and the design method of the hardware and software are discussed, The principle diagram of the hardware circuit implementing the control algorithm and the features of the software possessed are also presented.展开更多
A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP...A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.展开更多
In order to prevent drunk driving timely and protect personal safety,a kind of vehicle-loaded alcohol concentration detector based on single chip microcomputer control is designed.The detector usesAT89C51 microcontrol...In order to prevent drunk driving timely and protect personal safety,a kind of vehicle-loaded alcohol concentration detector based on single chip microcomputer control is designed.The detector usesAT89C51 microcontroller as the core,makes use of the gas sensor,A/D converter to detect the alcohol concentration of the breath of the driver,can set different thresholds according to the space of the car model,automatically cut off the ignition circuit for the exceeded threshold,and has the sound and light alarm function,which fundamentally solve the problem of drunk driving.The instrument is compact in size,stable in performance,convenient in installation and debugging,and of practical significance.展开更多
A single-chip UHF RFID reader transceiver IC has been implemented in 0.18 μm SiGe BiCMOS technology. The chip includes all transceiver blocks as RX/TX RF front-end, RX/TX analog baseband, frequency synthesizer and I2...A single-chip UHF RFID reader transceiver IC has been implemented in 0.18 μm SiGe BiCMOS technology. The chip includes all transceiver blocks as RX/TX RF front-end, RX/TX analog baseband, frequency synthesizer and I2C with fully-compliant China 800/900 MHz RFID draft, ISO/IEC 18000-6C protocol and ETSI 302 208-1 local regulation. The normal mode receiver in the presence of -3 dBm self-jammer achieves -75 dBm 1% PER sensitivity. The linear class-A PA integrated in transmitter has 25 dBm OP1 dB output power for CW. The fully-integrated fractional-N fre-quency synthesizer is designed based on MASH 1-1-1 sigma-delta modulator and 1.8 GHz fundamental frequency LC-VCO for lower in-band and out-of-band phase noise. The measured phase noise is up to -106 dBc/Hz@200 kHz and -131 dBc/Hz@1 MHz offset from center frequency and the integrated RMS jitter from 10 kHz to 10 MHz is less than 1.6 pS. The chip dissipates 330 mA from 3.3 V power supply when transmitting 22.4 dBm CW signal and the PAE of linear PA is up to 26%. The chip die area is 16.8 mm2.展开更多
The grading judgment for apples is related to a variety of factors including,size,shape,color,texture,and scars.Traditional manual sorting methods are time consuming and labor intensive.In addition,the accuracy of the...The grading judgment for apples is related to a variety of factors including,size,shape,color,texture,and scars.Traditional manual sorting methods are time consuming and labor intensive.In addition,the accuracy of the method is easily subjective,not repeatable,error-prone,and affected by the sorting environment.This paper presents a complete and automated grading system for apples.The system uses a single-chip microcomputer as the controller of the system,and a PC as the graphics processing unit.It also includes a conveyor,drive motor,frequency converter for motor control,photoelectric sensors,air compressor,and air jets for ejecting the graded apples.The classification algorithm is implemented by using a convolutional neural network(CNN).In order to eliminate contact damage of apples,the system specifically uses air jets as actuators to eject the graded apples into the corresponding bins.At the same time,in order to ensure that an apple triggers the correct ejecting actuator,this paper designs a jet controller with proper logic.展开更多
The paper introduces a temperature control systembased on AT89C51 single-chip-microprocessor, and discussesthe principle , hardware structure, and software design of thissystem in detail.
The test-QD in-situ annealing method could surmount the critical nucleation condition of InAs/GaAs single quantum dots(SQDs) to raise the growth repeatability.Here,through many growth tests on rotating substrates,we...The test-QD in-situ annealing method could surmount the critical nucleation condition of InAs/GaAs single quantum dots(SQDs) to raise the growth repeatability.Here,through many growth tests on rotating substrates,we develop a proper In deposition amount(θ) for SQD growth,according to the measured critical θ for test QD nucleation(θ;).The proper ratio θ/θ;,with a large tolerance of the variation of the real substrate temperature(T;),is 0.964-0.971 at the edge and> 0.989 but < 0.996 in the center of a 1/4-piece semi-insulating wafer,and around 0.9709 but < 0.9714 in the center of a 1/4-piece N;wafer as shown in the evolution of QD size and density as θ/θ;varies.Bright SQDs with spectral lines at 905 nm-935 nm nucleate at the edge and correlate with individual 7 nm-8 nm-height QDs in atomic force microscopy,among dense 1 nm-5 nm-height small QDs with a strong spectral profile around 860 nm-880 nm.The higher T;in the center forms diluter,taller and uniform QDs,and very dilute SQDs for a proper θ/θ;:only one 7-nm-height SQD in25 μm;.On a 2-inch(1 inch = 2.54 cm) semi-insulating wafer,by using θ/θ;= 0.961,SQDs nucleate in a circle in 22%of the whole area.More SQDs will form in the broad high-T;region in the center by using a proper θ/θ;.展开更多
将基于学习产出的教育模式(Outcome Based Education,OBE)引入单片机课程实践教学之中,设计了智慧教室监控系统的教学案例。系统可实现手动控灯和自动控灯、时钟显示、语音播报等功能。在实践中,以目标成果为导向,分功能模块,设计不同...将基于学习产出的教育模式(Outcome Based Education,OBE)引入单片机课程实践教学之中,设计了智慧教室监控系统的教学案例。系统可实现手动控灯和自动控灯、时钟显示、语音播报等功能。在实践中,以目标成果为导向,分功能模块,设计不同难度的学习目标,将虚拟仿真和实物搭建相结合,训练和培养学生基础模块知识、系统分析设计能力、专业素养和人文素养,循序渐进,并将融入思政元素和培养能力贯穿教学全过程,为其他专业课程实践教学提供参考。展开更多
针对单片机原理与接口技术课程在传统实践教学过程中,学生受规定时间、固定地点、指定实验设备的限制,实践与创新热情不能充分发挥的问题,该文以学生发展为中心,以提高学生实践能力为核心,构建ETPP渐进式从理论到实践、从仿真到实操的...针对单片机原理与接口技术课程在传统实践教学过程中,学生受规定时间、固定地点、指定实验设备的限制,实践与创新热情不能充分发挥的问题,该文以学生发展为中心,以提高学生实践能力为核心,构建ETPP渐进式从理论到实践、从仿真到实操的新型实践教学模式,打造完整的实践教学生态和全过程综合考核评价体系。学生使用51系列、STC15系列、Arduino UNO R3和STM32四种单片机便携式实验装置和多种传感器及外设模块,随时随地学习并实践,激发主动学习和探索实践的热情。实践教学表明,ETPP模式能够更好地培养实践能力强、创新能力强、符合社会需求的复合型创新型新工科人才,具有良好的教学效果。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.12305303)the Natural Science Foundation of Hunan Province of China(Grant Nos.2023JJ40520,2021JJ40444,and 2019JJ30019)+3 种基金the Research Foundation of Education Bureau of Hunan Province of China(Grant No.20A430)the Science and Technology Innovation Program of Hunan Province(Grant No.2020RC3054)the Natural Science Basic Research Plan in the Shaanxi Province of China(Grant No.2023-JC-QN-0015)the Doctoral Research Fund of University of South China。
文摘Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic particles, such as heavy ions, protons, and alpha particles, can induce single event effects(SEEs) that lead CNNs to malfunction and can significantly impact the reliability of a CNN system. In this paper, the MNIST CNN system was constructed based on a 28 nm systemon-chip(SoC), and then an alpha particle irradiation experiment and fault injection were applied to evaluate the SEE of the CNN system. Various types of soft errors in the CNN system have been detected, and the SEE cross sections have been calculated. Furthermore, the mechanisms behind some soft errors have been explained. This research will provide technical support for the design of radiation-resistant artificial intelligence chips.
文摘A DC regulated power supply with numerical control based on single chip microcomputer (SCM) is designed. SCM is the main controller and output voltage o{ DC power supply can be set by keyboard. The analog voltage can be obtained through D/A converter (DAC0832) so that different voltages can be provided by operational amplifier. The output voltage varies from 0 V to 12 V with the incremental value of 0. 1 V. The actual output voltage is shown in the nixietube. This DC regulated power supply is characterized by simple structure and easy operation.
基金Supported by the National Natural Science Foundation of China(11275164)~~
文摘With principles of reliability, independence, practicality and economical effi- ciency, a set of intelligent fire alarm system based on AVRmega128 single chip microcomputer was designed to solve problems of fire alarm system in many large- scale warehouses. Using advanced flame sensor, 485 bus communication, computer interactive software and related peripheral devices, this intelligent fire alarm system has functions of sound-light alarm and intelligent fire extinguishing. The human-com- puter interactive software was adopted for the remote control of the alarm main control panel through the 485 bus communication. This design of intelligent fire alarm system shows high reference and practical value to the development of intel- ligent alarm products with high integration and high reliability.
文摘Developed a new program structure using in single chip computer system, which based on multitasking mechanism. Discussed the specific method for realization of the new structure. The applied sample is also provided.
文摘Presents a one grade adaptive controller with one reference model which is built according to δ MRACS adaptive control theory and used to control an actual high order hydraulic system, and the whole hardware system used, which includes a AT89C51 single chip microcomputer, 74Ls373 flip latch, 6116 store, eight bit ADC0809, and so on, and the satisfactory results obtained in study on hydraulic control system.
基金supported by the National Natural Science Foundation of China(Grant Nos.11575138,11835006,11690040,and 11690043)
文摘Single-event effects(SEEs)induced by mediumenergy protons in a 28 nm system-on-chip(SoC)were investigated at the China Institute of Atomic Energy.An on-chip memory block was irradiated with 90 MeV and 70 MeV protons,respectively.Single-bit upset and multicell upset events were observed,and an uppermost number of nine upset cells were discovered in the 90 MeV proton irradiation test.The results indicate that the SEE sensitivities of the 28 nm SoC to the 90 MeV and 70 MeV protons were similar.Cosmic Ray Effects on Micro-Electronics Monte Carlo simulations were analyzed,and it demonstrates that protons can induce effects in a 28 nm SoC if their energies are greater than 1.4 MeV and that the lowest corresponding linear energy transfer was 0.142 MeV cm^2 mg^-1.The similarities and discrepancies of the SEEs induced by the 90 MeV and 70 MeV protons were analyzed.
基金supported by the National HighTech R&D Program of China(No.2015AA020408)National Natural Science Foundation of China(No.61204118,81500900 and21503054)+1 种基金Beijing Municipal Science and Technology Project(No.Z171100002017013)Key Research Program of the Chinese Academy of Sciences,Grant NO.KFZD-SW-210
文摘EGFR mutations companion diagnostics have been proved to be crucial for the efficacy of tyrosine kinase inhibitor targeted cancer therapies. To uncover multiple mutations occurred in minority of EGFR-mutated cells,which may be covered by the noises from majority of unmutated cells, is currently becoming an urgent clinical requirement. Here we present the validation of a microfluidic-chip-based method for detecting EGFR multimutations at single-cell level. By trapping and immunofluorescently imaging single cells in specifically designed silicon microwells, the EGFR-expressed cellswere easily identified. By in situ lysing single cells, the cell lysates of EGFR-expressed cells were retrieved without cross-contamination. Benefited from excluding the noise from cells without EGFR expression, the simple and cost-effective Sanger's sequencing, but not the expensive deep sequencing of the whole cell population, was used to discover multi-mutations. We verified the new method with precisely discovering three most important EGFR drugrelated mutations from a sample in which EGFR-mutated cells only account for a small percentage of whole cell population. The microfluidic chip is capable of discovering not only the existence of specific EGFR multi-mutations,but also other valuable single-cell-level information: on which specific cells the mutations occurred, or whether different mutations coexist on the same cells. This microfluidic chip constitutes a promising method to promote simple and cost-effective Sanger's sequencing to be a routine test before performing targeted cancer therapy.
文摘This paper introduces a SF vector control system of a slip frequency controlled induction mo-tor with simple structure,fair performance and convenient operation.It is realized by two singlechip microprocessors and fed from SPWM-GTR inverter.The whole system is combined by twosubsystems,both of them are 8031 single chip microprocessors.The communication between themis coordinated by the full duplex serial port within the chip and ask-and-answer communicationmanner.The error-corrected means adopted has improved the operation reliability of the system.A series of experimental results on a 3 kW induction motor are given at the end of this paper.
基金This work was financially supported by the National Natural Science Foundation of China. (No.20271033, 20335020, 90408014).
文摘A single molecule detection technique was developed by the combination of a single channel poly (dimethylsiloxane)/glass micro-fluidic chip and fluorescence correlation spectroscopy (FCS). This method was successfully used to determine the proportion of two model components in the mixture containing fluorescein and the rhodamine-green succinimidyl ester.
文摘Taking a specific production process as an example, this paper introduces the design of multi slot and unequal temperature PID controller based on single chip microcomputer. The mathematical implementation method of PID algorithm and the design method of the hardware and software are discussed, The principle diagram of the hardware circuit implementing the control algorithm and the features of the software possessed are also presented.
基金Supported by the National Basic Research Program of China under Grant No 2012CB933501the National Natural Science Foundation of China under Grant Nos 61307033,61274070,61137003 and 61321063
文摘A single mode hybrid Ⅲ-Ⅴ/silicon on-chip laser based on the flip-chip bonding technology for on-chip optical interconnection is demonstrated. A single mode Fabry-Perot laser structure with micro-structures on an InP ridge waveguide is designed and fabricated on an InP/AIGaInAs multiple quantum well epitaxial layer structure wafer by using i-line lithography. Then, a silicon waveguide platform including a laser mounting stage is designed and fabricated on a silicon-on-insulator substrate. The single mode laser is flip-chip bonded on the laser mounting stage. The lasing light is butt-coupling to the silicon waveguide. The laser power output from a silicon waveguide is 1.3roW, and the threshold is 37mA at room temperature and continuous wave operation.
基金This work was supported by the youth backbone teachers training program of Henan colleges and universities under Grant No.2016ggjs-287the project of science and technology of Henan province under Grant No.172102210124the Key Scientific Research projects in Colleges and Universities in Henan Grant No.18B460003.
文摘In order to prevent drunk driving timely and protect personal safety,a kind of vehicle-loaded alcohol concentration detector based on single chip microcomputer control is designed.The detector usesAT89C51 microcontroller as the core,makes use of the gas sensor,A/D converter to detect the alcohol concentration of the breath of the driver,can set different thresholds according to the space of the car model,automatically cut off the ignition circuit for the exceeded threshold,and has the sound and light alarm function,which fundamentally solve the problem of drunk driving.The instrument is compact in size,stable in performance,convenient in installation and debugging,and of practical significance.
文摘A single-chip UHF RFID reader transceiver IC has been implemented in 0.18 μm SiGe BiCMOS technology. The chip includes all transceiver blocks as RX/TX RF front-end, RX/TX analog baseband, frequency synthesizer and I2C with fully-compliant China 800/900 MHz RFID draft, ISO/IEC 18000-6C protocol and ETSI 302 208-1 local regulation. The normal mode receiver in the presence of -3 dBm self-jammer achieves -75 dBm 1% PER sensitivity. The linear class-A PA integrated in transmitter has 25 dBm OP1 dB output power for CW. The fully-integrated fractional-N fre-quency synthesizer is designed based on MASH 1-1-1 sigma-delta modulator and 1.8 GHz fundamental frequency LC-VCO for lower in-band and out-of-band phase noise. The measured phase noise is up to -106 dBc/Hz@200 kHz and -131 dBc/Hz@1 MHz offset from center frequency and the integrated RMS jitter from 10 kHz to 10 MHz is less than 1.6 pS. The chip dissipates 330 mA from 3.3 V power supply when transmitting 22.4 dBm CW signal and the PAE of linear PA is up to 26%. The chip die area is 16.8 mm2.
文摘The grading judgment for apples is related to a variety of factors including,size,shape,color,texture,and scars.Traditional manual sorting methods are time consuming and labor intensive.In addition,the accuracy of the method is easily subjective,not repeatable,error-prone,and affected by the sorting environment.This paper presents a complete and automated grading system for apples.The system uses a single-chip microcomputer as the controller of the system,and a PC as the graphics processing unit.It also includes a conveyor,drive motor,frequency converter for motor control,photoelectric sensors,air compressor,and air jets for ejecting the graded apples.The classification algorithm is implemented by using a convolutional neural network(CNN).In order to eliminate contact damage of apples,the system specifically uses air jets as actuators to eject the graded apples into the corresponding bins.At the same time,in order to ensure that an apple triggers the correct ejecting actuator,this paper designs a jet controller with proper logic.
文摘The paper introduces a temperature control systembased on AT89C51 single-chip-microprocessor, and discussesthe principle , hardware structure, and software design of thissystem in detail.
基金supported by the National Key Basic Research Program of China(Grant No.2013CB933304)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB01010200)the National Natural Science Foundation of China(Grant No.65015196)
文摘The test-QD in-situ annealing method could surmount the critical nucleation condition of InAs/GaAs single quantum dots(SQDs) to raise the growth repeatability.Here,through many growth tests on rotating substrates,we develop a proper In deposition amount(θ) for SQD growth,according to the measured critical θ for test QD nucleation(θ;).The proper ratio θ/θ;,with a large tolerance of the variation of the real substrate temperature(T;),is 0.964-0.971 at the edge and> 0.989 but < 0.996 in the center of a 1/4-piece semi-insulating wafer,and around 0.9709 but < 0.9714 in the center of a 1/4-piece N;wafer as shown in the evolution of QD size and density as θ/θ;varies.Bright SQDs with spectral lines at 905 nm-935 nm nucleate at the edge and correlate with individual 7 nm-8 nm-height QDs in atomic force microscopy,among dense 1 nm-5 nm-height small QDs with a strong spectral profile around 860 nm-880 nm.The higher T;in the center forms diluter,taller and uniform QDs,and very dilute SQDs for a proper θ/θ;:only one 7-nm-height SQD in25 μm;.On a 2-inch(1 inch = 2.54 cm) semi-insulating wafer,by using θ/θ;= 0.961,SQDs nucleate in a circle in 22%of the whole area.More SQDs will form in the broad high-T;region in the center by using a proper θ/θ;.
文摘将基于学习产出的教育模式(Outcome Based Education,OBE)引入单片机课程实践教学之中,设计了智慧教室监控系统的教学案例。系统可实现手动控灯和自动控灯、时钟显示、语音播报等功能。在实践中,以目标成果为导向,分功能模块,设计不同难度的学习目标,将虚拟仿真和实物搭建相结合,训练和培养学生基础模块知识、系统分析设计能力、专业素养和人文素养,循序渐进,并将融入思政元素和培养能力贯穿教学全过程,为其他专业课程实践教学提供参考。
文摘针对单片机原理与接口技术课程在传统实践教学过程中,学生受规定时间、固定地点、指定实验设备的限制,实践与创新热情不能充分发挥的问题,该文以学生发展为中心,以提高学生实践能力为核心,构建ETPP渐进式从理论到实践、从仿真到实操的新型实践教学模式,打造完整的实践教学生态和全过程综合考核评价体系。学生使用51系列、STC15系列、Arduino UNO R3和STM32四种单片机便携式实验装置和多种传感器及外设模块,随时随地学习并实践,激发主动学习和探索实践的热情。实践教学表明,ETPP模式能够更好地培养实践能力强、创新能力强、符合社会需求的复合型创新型新工科人才,具有良好的教学效果。