Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the ...Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.展开更多
Radiation source identification plays an important role in non-cooperative communication scene and numerous methods have been proposed in this field. Deep learning has gained popularity in a variety of computer vision...Radiation source identification plays an important role in non-cooperative communication scene and numerous methods have been proposed in this field. Deep learning has gained popularity in a variety of computer vision tasks. Recently, it has also been successfully applied for radiation source identification.However, training deep neural networks for classification requires a large number of labeled samples, and in non-cooperative applications, it is unrealistic. This paper proposes a method for the unlabeled samples of unknown radiation source. It uses semi-supervised learning to detect unlabeled samples and label new samples automatically. It avoids retraining the neural network with parameter-transfer learning. The results show that compared with the traditional algorithms, the proposed algorithm can offer better accuracy.展开更多
In order to acquire a broadband absorption spectrum in a single shot,a compact radiation source was developed by using a Z-pinch type electric discharge.This paper presents the mechanical and electrical construction o...In order to acquire a broadband absorption spectrum in a single shot,a compact radiation source was developed by using a Z-pinch type electric discharge.This paper presents the mechanical and electrical construction of the source,as well as its electrical and optical characteristics,including the intense continuum of radiation emitted by the source in the UV and visible spectral range.It also shows that the compactness of the source allows direct coupling with the probed medium,enabling broadband absorption measurement in the spectral range of 200e300 nm without use of an optical fiber which strongly attenuates the light in the short wavelength range.Concretely,thanks to this source,broadband spectral absorption of NO molecules around 210 nm and that of OH molecules around 310 nm were recorded in this direct coupling arrangement.Copper atom spectral absorption around 325 nm of the peripheral cold zones of an intense transient arc was also recorded.展开更多
An equivalent radiation source method is proposed to characterize electromagnetic emission and interference of complex three dimensional integrated circuits(IC) in this paper.The method utilizes amplitude-only near-fi...An equivalent radiation source method is proposed to characterize electromagnetic emission and interference of complex three dimensional integrated circuits(IC) in this paper.The method utilizes amplitude-only near-field scanning data to reconstruct an equivalent magnetic dipole array,and the differential evolution optimization algorithm is proposed to extract the locations,orientation and moments of those dipoles.By importing the equivalent dipoles model into a 3D full-wave simulator together with the victim circuit model,the electromagnetic interference issues in mixed RF/digital systems can be well predicted.A commercial IC is used to validate the accuracy and efficiency of this proposed method.The coupled power at the victim antenna port calculated by the equivalent radiation source is compared with the measured data.Good consistency is obtained which confirms the validity and efficiency of the method.展开更多
In recent years,in order to meet the practical needs of deep edge mine detection with large depth and high precision,transient electromagnetic method(TEM)near emission source detection mode has become an international...In recent years,in order to meet the practical needs of deep edge mine detection with large depth and high precision,transient electromagnetic method(TEM)near emission source detection mode has become an international advanced method(Xue et al.,2020).展开更多
The PeTa (Perelman-Tatartchenko) effect is the radiation of the energy of a first-order phase transition during the transition from a less condensed phase to a more condensed one. The effect was independently discover...The PeTa (Perelman-Tatartchenko) effect is the radiation of the energy of a first-order phase transition during the transition from a less condensed phase to a more condensed one. The effect was independently discovered by M. Perelman and the author of this paper. Six papers on the PeTa effect have been published in this journal over the past nine years. They are devoted to the development of PeTa models to explain the following phenomena: IR radiation from cold surfaces, cavitation luminescence/sonoluminescence (CL/SL), laser-induced bubble luminescence (LIBL), and vapor bubble luminescence (VBL) in underwater geysers. This paper describes the sources of PeTa radiation in the Earth’s atmosphere. These sources of infrared radiation have been investigated by numerous research groups, but their interpretation either does not exist at all, or it is erroneous. The following phenomena are specifically considered: PeTa radiation during the formation of clouds and fog;a pulse laser based on the PeTa radiation;condensation explosions as sources of PaTa radiation;measurement of the concentration of water vapor in the atmosphere using PeTa radiation;atmospheric scintillation of infrared radiation in the atmosphere due to the PeTa effect;PeTa radiation as a source of comfort for the igloo;the influence of PeTa radiation on living organisms;PeTa radiation due to characteristics of tropical storms;PeTa radiation as a possible precursor to earthquakes. The problem of global warming, which worries everyone, as it turns out, is also associated with the PeTa effect.展开更多
MCNPX(Monte Carlo N-Particle Transport Code)computer code is used to design a model to CANDU(Canada Deuterium Uranium)reactor core and its shielding system.It is assumed that reactor core is fueled with natural uraniu...MCNPX(Monte Carlo N-Particle Transport Code)computer code is used to design a model to CANDU(Canada Deuterium Uranium)reactor core and its shielding system.It is assumed that reactor core is fueled with natural uranium.The core radiation sources are calculated which consider prompt neutrons,neutron induced gamma and prompt gamma radiations.The total neutron flux and dose rate are calculated along the shield and at outer shield points.The results indicated that the major dose rate component at outer shield points is due to neutron induced gamma dose rate(μSv/h).展开更多
A theoretical model is presented to describe the parametric acoustic field generated by a piston radiator. In the model, the high-frequency primary wave interaction region that is truncated by a low-pass acoustic filt...A theoretical model is presented to describe the parametric acoustic field generated by a piston radiator. In the model, the high-frequency primary wave interaction region that is truncated by a low-pass acoustic filter can be viewed as a cylindrical source within the Rayleigh distance of the piston. When the radius of the piston is much smaller than the length of the parametric region, this model is reduced to the Berketey’s End-Fire Line Army model. Comparison between numerical calculations and experimental measurement show that the generated parametric sound field (especially near the axis) agrees well with the experiment results.展开更多
Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototy...Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototype was an active attempt and early exploration for future APPLE–Knot undulator,which will be used at high energy photon source(HEPS).Materials and methods There are several challenges to develop a cryogenic delta undulator,such as the complicated structure,the influence of large magnetic force,and the magnetic measurement difficulty due to the very small gap.In this paper,the mechanical design for overcoming these difficulties will be presented in detail.Conclusion A special hall measuring system is developed,and the preliminary results agree with the theoretical results.This undulator prototype will provide valuable experience for angle magnetization technology,intricate magnetic attraction structure design,and magnetic field measurement under closed small space.展开更多
Using both fast and slow electric field change sensors and field mill,multi-station observations on lightning flashes over China inland plateau areas were conducted during the summer of 2004.All of the stations were s...Using both fast and slow electric field change sensors and field mill,multi-station observations on lightning flashes over China inland plateau areas were conducted during the summer of 2004.All of the stations were synchronized by GPS with a time-resolution of±50 ns.Using the different time of arrival(DTOA)and based on the fast electric field change sensor,a lightning radiation location technique was developed.Radiation pulses in the initial stages of five intracloud(IC)lightning discharges which occurred on 20 August were analyzed.The results indicate that the technique developed could effectively locate the lightning radiation sources.Furthermore,the lightning discharges were compared with the Doppler radar data.The results show that the radiation sources were well associated with the storm development.When the storm was at the mature stage with an echo top of about 10.9 km,the radiation sources ranged from 5.2 to 8.3 km above mean sea level;when the storm gradually became weaker,with echo top of about 7.9 km,the radiation sources ranged from 3.0 to 5.9 km.In particular,one of the IC lightning discharges ranged from 3.0 to 4.9 km during the dissipation stage of the storm.The results also indicate that the radiation sources were closely associated with the high reflectivity region(25-50 dBZ)of the storm,which,to some extent,demonstrates the reliability of the location results,thereby showing that multi-station observations of fast electric field change sensors could be a useful tool for monitoring the storm development.Location errors from radiation sources were also compared with the radar data and the results of a simple simulation.It was found that the errors were getting smaller when the radiation sources approached the center of the detection network, and vice versa.Compared with the limited experimental observations,the simulation results were found capable of effectively reflecting the location errors.展开更多
The Giant Radio Array for Neutrino Detection(GRAND)is a planned large-scale observatory of ultra-high-energy(UHE)cosmic particles,with energies exceeding 10~8 Ge V.Its goal is to solve the long-standing mystery of the...The Giant Radio Array for Neutrino Detection(GRAND)is a planned large-scale observatory of ultra-high-energy(UHE)cosmic particles,with energies exceeding 10~8 Ge V.Its goal is to solve the long-standing mystery of the origin of UHE cosmic rays.To do this,GRAND will detect an unprecedented number of UHE cosmic rays and search for the undiscovered UHE neutrinos and gamma rays associated to them with unmatched sensitivity.GRAND will use large arrays of antennas to detect the radio emission coming from extensive air showers initiated by UHE particles in the atmosphere.Its design is modular:20 separate,independent sub-arrays,each of 10000 radio antennas deployed over 10000 km^2.A staged construction plan will validate key detection techniques while achieving important science goals early.Here we present the science goals,detection strategy,preliminary design,performance goals,and construction plans for GRAND.展开更多
With the latest configuration,the Ti:Sa laser system ARCTURUS(Düsseldorf University,Germany)operates with a double-chirped pulse amplification(CPA)architecture delivering pulses with an energy of 7 J before compr...With the latest configuration,the Ti:Sa laser system ARCTURUS(Düsseldorf University,Germany)operates with a double-chirped pulse amplification(CPA)architecture delivering pulses with an energy of 7 J before compression in each of the two high-power beams.By the implementation of a plasma mirror system,the intrinsic laser contrast is enhanced up to 10^-12 on a time scale of hundreds of picoseconds,before the main peak.The laser system has been used in various configurations for advanced experiments and different studies have been carried out employing the high-power laser beams as a single,high-intensity interaction beam(I≈1020 W/cm^2),in dual-and multi-beam configurations or in a pump–probe arrangement.展开更多
基金National Natural Science Foundation of China under Grant No.61973037China Postdoctoral Science Foundation under Grant No.2022M720419。
文摘Automatic modulation recognition(AMR)of radiation source signals is a research focus in the field of cognitive radio.However,the AMR of radiation source signals at low SNRs still faces a great challenge.Therefore,the AMR method of radiation source signals based on two-dimensional data matrix and improved residual neural network is proposed in this paper.First,the time series of the radiation source signals are reconstructed into two-dimensional data matrix,which greatly simplifies the signal preprocessing process.Second,the depthwise convolution and large-size convolutional kernels based residual neural network(DLRNet)is proposed to improve the feature extraction capability of the AMR model.Finally,the model performs feature extraction and classification on the two-dimensional data matrix to obtain the recognition vector that represents the signal modulation type.Theoretical analysis and simulation results show that the AMR method based on two-dimensional data matrix and improved residual network can significantly improve the accuracy of the AMR method.The recognition accuracy of the proposed method maintains a high level greater than 90% even at -14 dB SNR.
基金supported by the National Key R&D Program of China (2018YFB2101300)。
文摘Radiation source identification plays an important role in non-cooperative communication scene and numerous methods have been proposed in this field. Deep learning has gained popularity in a variety of computer vision tasks. Recently, it has also been successfully applied for radiation source identification.However, training deep neural networks for classification requires a large number of labeled samples, and in non-cooperative applications, it is unrealistic. This paper proposes a method for the unlabeled samples of unknown radiation source. It uses semi-supervised learning to detect unlabeled samples and label new samples automatically. It avoids retraining the neural network with parameter-transfer learning. The results show that compared with the traditional algorithms, the proposed algorithm can offer better accuracy.
文摘In order to acquire a broadband absorption spectrum in a single shot,a compact radiation source was developed by using a Z-pinch type electric discharge.This paper presents the mechanical and electrical construction of the source,as well as its electrical and optical characteristics,including the intense continuum of radiation emitted by the source in the UV and visible spectral range.It also shows that the compactness of the source allows direct coupling with the probed medium,enabling broadband absorption measurement in the spectral range of 200e300 nm without use of an optical fiber which strongly attenuates the light in the short wavelength range.Concretely,thanks to this source,broadband spectral absorption of NO molecules around 210 nm and that of OH molecules around 310 nm were recorded in this direct coupling arrangement.Copper atom spectral absorption around 325 nm of the peripheral cold zones of an intense transient arc was also recorded.
基金supported by the National Nature Science Foundation of China(No.61274110)
文摘An equivalent radiation source method is proposed to characterize electromagnetic emission and interference of complex three dimensional integrated circuits(IC) in this paper.The method utilizes amplitude-only near-field scanning data to reconstruct an equivalent magnetic dipole array,and the differential evolution optimization algorithm is proposed to extract the locations,orientation and moments of those dipoles.By importing the equivalent dipoles model into a 3D full-wave simulator together with the victim circuit model,the electromagnetic interference issues in mixed RF/digital systems can be well predicted.A commercial IC is used to validate the accuracy and efficiency of this proposed method.The coupled power at the victim antenna port calculated by the equivalent radiation source is compared with the measured data.Good consistency is obtained which confirms the validity and efficiency of the method.
基金project supported by Science and Technology Innovation Fund(Grant No.KDY2019001)Integrated Geophysical Simulation Lab of Chang’an University(Key Laboratory of Chinese Geophysical Society)
文摘In recent years,in order to meet the practical needs of deep edge mine detection with large depth and high precision,transient electromagnetic method(TEM)near emission source detection mode has become an international advanced method(Xue et al.,2020).
文摘The PeTa (Perelman-Tatartchenko) effect is the radiation of the energy of a first-order phase transition during the transition from a less condensed phase to a more condensed one. The effect was independently discovered by M. Perelman and the author of this paper. Six papers on the PeTa effect have been published in this journal over the past nine years. They are devoted to the development of PeTa models to explain the following phenomena: IR radiation from cold surfaces, cavitation luminescence/sonoluminescence (CL/SL), laser-induced bubble luminescence (LIBL), and vapor bubble luminescence (VBL) in underwater geysers. This paper describes the sources of PeTa radiation in the Earth’s atmosphere. These sources of infrared radiation have been investigated by numerous research groups, but their interpretation either does not exist at all, or it is erroneous. The following phenomena are specifically considered: PeTa radiation during the formation of clouds and fog;a pulse laser based on the PeTa radiation;condensation explosions as sources of PaTa radiation;measurement of the concentration of water vapor in the atmosphere using PeTa radiation;atmospheric scintillation of infrared radiation in the atmosphere due to the PeTa effect;PeTa radiation as a source of comfort for the igloo;the influence of PeTa radiation on living organisms;PeTa radiation due to characteristics of tropical storms;PeTa radiation as a possible precursor to earthquakes. The problem of global warming, which worries everyone, as it turns out, is also associated with the PeTa effect.
文摘MCNPX(Monte Carlo N-Particle Transport Code)computer code is used to design a model to CANDU(Canada Deuterium Uranium)reactor core and its shielding system.It is assumed that reactor core is fueled with natural uranium.The core radiation sources are calculated which consider prompt neutrons,neutron induced gamma and prompt gamma radiations.The total neutron flux and dose rate are calculated along the shield and at outer shield points.The results indicated that the major dose rate component at outer shield points is due to neutron induced gamma dose rate(μSv/h).
文摘A theoretical model is presented to describe the parametric acoustic field generated by a piston radiator. In the model, the high-frequency primary wave interaction region that is truncated by a low-pass acoustic filter can be viewed as a cylindrical source within the Rayleigh distance of the piston. When the radius of the piston is much smaller than the length of the parametric region, this model is reduced to the Berketey’s End-Fire Line Army model. Comparison between numerical calculations and experimental measurement show that the generated parametric sound field (especially near the axis) agrees well with the experiment results.
基金The Grant No.is 11675207.Project name:The Physical and Technical Study of Quasi-eriodic DELTA Undulator working at liquid nitrogen temperature.
文摘Introduction A novel type of pure permanent cryogenic Delta–Knot Undulator was developed at IHEP to supply a high flux of full adjustable polarization synchrotron radiation with low on-axis power density.This prototype was an active attempt and early exploration for future APPLE–Knot undulator,which will be used at high energy photon source(HEPS).Materials and methods There are several challenges to develop a cryogenic delta undulator,such as the complicated structure,the influence of large magnetic force,and the magnetic measurement difficulty due to the very small gap.In this paper,the mechanical design for overcoming these difficulties will be presented in detail.Conclusion A special hall measuring system is developed,and the preliminary results agree with the theoretical results.This undulator prototype will provide valuable experience for angle magnetization technology,intricate magnetic attraction structure design,and magnetic field measurement under closed small space.
基金the 100 Talents Program of the Chinese Academy of Sciencesthe Special Research Project for Public Welfare of China under Grant No.200704027-1the National Natural Science Foundation of China under Grant No.40930949
文摘Using both fast and slow electric field change sensors and field mill,multi-station observations on lightning flashes over China inland plateau areas were conducted during the summer of 2004.All of the stations were synchronized by GPS with a time-resolution of±50 ns.Using the different time of arrival(DTOA)and based on the fast electric field change sensor,a lightning radiation location technique was developed.Radiation pulses in the initial stages of five intracloud(IC)lightning discharges which occurred on 20 August were analyzed.The results indicate that the technique developed could effectively locate the lightning radiation sources.Furthermore,the lightning discharges were compared with the Doppler radar data.The results show that the radiation sources were well associated with the storm development.When the storm was at the mature stage with an echo top of about 10.9 km,the radiation sources ranged from 5.2 to 8.3 km above mean sea level;when the storm gradually became weaker,with echo top of about 7.9 km,the radiation sources ranged from 3.0 to 5.9 km.In particular,one of the IC lightning discharges ranged from 3.0 to 4.9 km during the dissipation stage of the storm.The results also indicate that the radiation sources were closely associated with the high reflectivity region(25-50 dBZ)of the storm,which,to some extent,demonstrates the reliability of the location results,thereby showing that multi-station observations of fast electric field change sensors could be a useful tool for monitoring the storm development.Location errors from radiation sources were also compared with the radar data and the results of a simple simulation.It was found that the errors were getting smaller when the radiation sources approached the center of the detection network, and vice versa.Compared with the limited experimental observations,the simulation results were found capable of effectively reflecting the location errors.
基金The GRAND project is supported by the APACHE of the French Agence Nationale de la Recherche(Grant No.ANR-16-CE31-0001)the FranceChina Particle Physics Laboratory,the China Exchange Program from the Royal Netherlands Academy of Arts and Sciences and the Chinese Academy of Sciences+15 种基金the Key Projects of Frontier Science of the Chinese Academy of Sciences(Grant No.QYZDY-SSW-SLH022)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB23000000)the National Key R&D Program of China(Grant No.2018YFA0404601)supported by Sao Paulo Research Foundation(FAPESP)(Grant No.2017/12828-4)partially supported from National Science Foundation(Grant Nos.PHY-1404311,and PHY-1714479)supported by Danish National Research Foundation(DNRF91)Danmarks Grundforskningsfond(Grant No.1041811001)Villum Fonden(Grant No.13164)Washington Carvalho Jr.is supported by Sao Paulo Research Foundation(FAPESP)(Grant No.2015/15735-1)supported by the National Natural Science Foundation of China(Grant No.11375209)supported by the Flemish Foundation for Scientific Research(Grant No.FWO-12L3715N–K.D.de Vries)supported by the Netherlands Organisation for Scientific Research(NWO)supported by the Key Projects of Frontier Science of Chinese Academy of Sciences,(Grant No.QYZDY-SSWSLH022)the Strategic Priority Research Program of Chinese Academy of Sciences,(Grant No.XDB23000000)supported by the National Natural Science Foundation of China(Grant No.11505213)“Data analysis for radio detection array at 21CMA base”
文摘The Giant Radio Array for Neutrino Detection(GRAND)is a planned large-scale observatory of ultra-high-energy(UHE)cosmic particles,with energies exceeding 10~8 Ge V.Its goal is to solve the long-standing mystery of the origin of UHE cosmic rays.To do this,GRAND will detect an unprecedented number of UHE cosmic rays and search for the undiscovered UHE neutrinos and gamma rays associated to them with unmatched sensitivity.GRAND will use large arrays of antennas to detect the radio emission coming from extensive air showers initiated by UHE particles in the atmosphere.Its design is modular:20 separate,independent sub-arrays,each of 10000 radio antennas deployed over 10000 km^2.A staged construction plan will validate key detection techniques while achieving important science goals early.Here we present the science goals,detection strategy,preliminary design,performance goals,and construction plans for GRAND.
基金supported by the DFG Transregio SFB/TR18 and GRK 1203 programs
文摘With the latest configuration,the Ti:Sa laser system ARCTURUS(Düsseldorf University,Germany)operates with a double-chirped pulse amplification(CPA)architecture delivering pulses with an energy of 7 J before compression in each of the two high-power beams.By the implementation of a plasma mirror system,the intrinsic laser contrast is enhanced up to 10^-12 on a time scale of hundreds of picoseconds,before the main peak.The laser system has been used in various configurations for advanced experiments and different studies have been carried out employing the high-power laser beams as a single,high-intensity interaction beam(I≈1020 W/cm^2),in dual-and multi-beam configurations or in a pump–probe arrangement.
