Some electrical parameters of the SIS-type hysteretic underdamped Josephson junction(JJ)can be measured by its current-voltage characteristics(IVCs).Currents and voltages at JJ are commensurate with the intrinsic nois...Some electrical parameters of the SIS-type hysteretic underdamped Josephson junction(JJ)can be measured by its current-voltage characteristics(IVCs).Currents and voltages at JJ are commensurate with the intrinsic noise level of measuring instruments.This leads to the need for multiple measurements with subsequent statistical processing.In this paper,the digital algorithms are proposed for the automatic measurement of the JJ parameters by IVC.These algorithms make it possible to implement multiple measurements and check these JJ parameters in an automatic mode with the required accuracy.The complete sufficient statistics are used to minimize the root-mean-square error of parameter measurement.A sequence of current pulses with slow rising and falling edges is used to drive JJ,and synchronous current and voltage readings at JJ are used to realize measurement algorithms.The algorithm performance is estimated through computer simulations.The significant advantage of the proposed algorithms is the independence from current source noise and intrinsic noise of current and voltage meters,as well as the simple implementation in automatic digital measuring systems.The proposed algorithms can be used to control JJ parameters during mass production of superconducting integrated circuits,which will improve the production efficiency and product quality.展开更多
The algorithm for evaluation of fiber orientation distribution function (ODF) by laser scattering method based on 2 - dimentional model of fiber arrangement and the method of determining diffuse scattering intensity a...The algorithm for evaluation of fiber orientation distribution function (ODF) by laser scattering method based on 2 - dimentional model of fiber arrangement and the method of determining diffuse scattering intensity are presented. The fiber ODFs of nonwoven samples measured by the computer-program-controlled laser scattering intensity testing system are compared with that of the data obtained by microprojector method. The results show that the algorithm is feasible for assessing the fiber ODFs of nonwoven fabrics manufactured by different processing methods.展开更多
A universal and low-cost temperature thermometer is realized via a special circuit,integrated circuit chip with microprocessor and analog to digital converter,and digital bus interface.Various thermocouples and resist...A universal and low-cost temperature thermometer is realized via a special circuit,integrated circuit chip with microprocessor and analog to digital converter,and digital bus interface.Various thermocouples and resistance temperature detectors used for temperature sensing may be connected to same thermometer.A special signal condition circuitry is designed and a matching algorithm is proposed.A novel calibration method named disassembled calibration is proposed in order to enhance efficiency and flexibility for the whole system.Additionally,it presents a combination method of low order polynomial fitting and piecewise linearity for the nonlinearity calibration of the thermocouple and the resistance temperature detector.A cold junction compensation based on digital way is described.And the matching algorithm and calibration method may eliminate errors stemming from excitation voltage source and reference voltage source,and can weaken quantization error of analog to digital converter and drift of components,too.Furthermore,the 400 times oversampling is completed by sequential and equal interval sampling to upgrade accuracy of analog to digital converter from original 12 to 15 bits and to raise signal-to-noise ratio.Finally,during a long time monitoring,experiment results show that errors at each static point are less than±0.2°C for the thermocouple system and less than±0.1°C for the resistance temperature detector system.展开更多
基金the Ministry of Science and Higher Education of the Russian Federation under Grant No.FSUN-2023-0007.
文摘Some electrical parameters of the SIS-type hysteretic underdamped Josephson junction(JJ)can be measured by its current-voltage characteristics(IVCs).Currents and voltages at JJ are commensurate with the intrinsic noise level of measuring instruments.This leads to the need for multiple measurements with subsequent statistical processing.In this paper,the digital algorithms are proposed for the automatic measurement of the JJ parameters by IVC.These algorithms make it possible to implement multiple measurements and check these JJ parameters in an automatic mode with the required accuracy.The complete sufficient statistics are used to minimize the root-mean-square error of parameter measurement.A sequence of current pulses with slow rising and falling edges is used to drive JJ,and synchronous current and voltage readings at JJ are used to realize measurement algorithms.The algorithm performance is estimated through computer simulations.The significant advantage of the proposed algorithms is the independence from current source noise and intrinsic noise of current and voltage meters,as well as the simple implementation in automatic digital measuring systems.The proposed algorithms can be used to control JJ parameters during mass production of superconducting integrated circuits,which will improve the production efficiency and product quality.
基金This project is supported by Key Subject Foundation of Shanghai Educational Committee.
文摘The algorithm for evaluation of fiber orientation distribution function (ODF) by laser scattering method based on 2 - dimentional model of fiber arrangement and the method of determining diffuse scattering intensity are presented. The fiber ODFs of nonwoven samples measured by the computer-program-controlled laser scattering intensity testing system are compared with that of the data obtained by microprojector method. The results show that the algorithm is feasible for assessing the fiber ODFs of nonwoven fabrics manufactured by different processing methods.
基金the Beijing Municipal Education Commission Science Technology Fund(No.KM201411232015)the Project of Construction of Innovative Teams and Teacher Career Development for Universities and Colleges Under Beijing Municipality(No.IDHT20130519)the National Natural Science Foundation of China(No.61272375)
文摘A universal and low-cost temperature thermometer is realized via a special circuit,integrated circuit chip with microprocessor and analog to digital converter,and digital bus interface.Various thermocouples and resistance temperature detectors used for temperature sensing may be connected to same thermometer.A special signal condition circuitry is designed and a matching algorithm is proposed.A novel calibration method named disassembled calibration is proposed in order to enhance efficiency and flexibility for the whole system.Additionally,it presents a combination method of low order polynomial fitting and piecewise linearity for the nonlinearity calibration of the thermocouple and the resistance temperature detector.A cold junction compensation based on digital way is described.And the matching algorithm and calibration method may eliminate errors stemming from excitation voltage source and reference voltage source,and can weaken quantization error of analog to digital converter and drift of components,too.Furthermore,the 400 times oversampling is completed by sequential and equal interval sampling to upgrade accuracy of analog to digital converter from original 12 to 15 bits and to raise signal-to-noise ratio.Finally,during a long time monitoring,experiment results show that errors at each static point are less than±0.2°C for the thermocouple system and less than±0.1°C for the resistance temperature detector system.
