The signs of the electric field markers in Figs.2 and 4 of the paper[Chin.Phys.B 32104211(2023)]have been corrected.These modifications do not affect the results derived in the paper.
Atoms in the microscopic world are the basic building blocks of the macroscopic world. In this work, we construct an atomic-scale electromagnetic theory that bridges optics in the microscopic and macroscopic worlds. A...Atoms in the microscopic world are the basic building blocks of the macroscopic world. In this work, we construct an atomic-scale electromagnetic theory that bridges optics in the microscopic and macroscopic worlds. As the building block of the theory, we use the microscopic polarizability to describe the optical response of a single atom, solve the transport of electromagnetic wave through a single atomic layer under arbitrary incident angle and polarization of the light beam, construct the single atomic layer transfer matrix for light transport across the atomic layer. Based on this transfer matrix, we get the analytical form of the dispersion relation, refractive index, and transmission/reflection coefficient of the macroscopic medium. The developed theory can handle single-layer and few-layers of homogeneous and heterogeneous 2D materials, investigate homogeneous 2D materials with various vacancies or insertion atomic-layer defects, study compound 2D materials with a unit cell composed of several elements in both the lateral and parallel directions with respect to the light transport.展开更多
It is currently believed that light quantum or the quantization of light energy is beyond classical physics, and the picture of wave-particle duality, which was criticized by Einstein but has attracted a number of exp...It is currently believed that light quantum or the quantization of light energy is beyond classical physics, and the picture of wave-particle duality, which was criticized by Einstein but has attracted a number of experimental researches, is necessary for the description of light. It is shown in this paper, however, that the quantization of light energy in vacuum, which is the same as that in quantum electrodynamics, can be derived directly from the classical electromagnetic theory through the consideration of statistics based on classical physics. Therefore, the quantization of energy is an intrinsic property of light as a classical electromagnetic wave and has no need of being related to particles.展开更多
Many domestic and international scholars have done a wide range of researches on electromagnetic and technology and have made some achievements. Electromagnetic technology has been used in forest pests control as a c...Many domestic and international scholars have done a wide range of researches on electromagnetic and technology and have made some achievements. Electromagnetic technology has been used in forest pests control as a convenient and high-efficient physics means. This article summaries the current study of the electromagnetic biological effect and introduces the appfication of microwave, pulsed electromagnetic field and electrostatic field to forest pests control. The research direction and prospect of the application of electromagnetic theory and technology to forest pests control arc also discussed.展开更多
This paper presents the principle of electromagnetic missile from the mathematical point of view, and verifies rigorously that the radiating power over whole space is limited.
In the course of designing and developing different-purpose electrodynamical devices,electromagnetic processes in movable and immovable media need to be calculated simultaneously.The solution for such tasks based on t...In the course of designing and developing different-purpose electrodynamical devices,electromagnetic processes in movable and immovable media need to be calculated simultaneously.The solution for such tasks based on the electromagnetic field theory is associated with the emergence of significant theoretical and practical difficulties.The problems that arise during the calculation of electromagnetic processes in movable and immovable media of electrodynamical devices using the electromagnetic field theory are examined in this study.Improved approaches toward the calculation of electromagnetic processes in electrodynamical devices using Maxwell’s equations are suggested.Notably,calculating electromagnetic processes in movable and immovable media using Maxwell’s equations necessitates consideration of the systems of coordinates where the electromagnetic phenomena are analyzed.Theoretically substantiated methods of calculating electromagnetic processes in movable and immovable media based on the principles of electromagnetic field theory are proposed.The methods consider the systems of coordinates where the analysis of electromagnetic phenomena is conducted.The effectiveness of the suggested methods for example in calculating electromagnetic processes in movable and immovable media of the turbogenerator is illustrated.展开更多
This article argues that the Haitian Vodou spirits(lwas)of fertility and death,Gede,do not promote homosexuality or the fluidity of sexuality in Haitian culture.The latter position is a Western reading of Gede grounde...This article argues that the Haitian Vodou spirits(lwas)of fertility and death,Gede,do not promote homosexuality or the fluidity of sexuality in Haitian culture.The latter position is a Western reading of Gede grounded in postmodern and post-structural identity theorizing.Gede in Haitian ontology and epistemology is lwas of fertility and death not sexual identity confusion or fluidity.展开更多
By using a finite difference time domain (FDTD) method, the effects of a one-dimensional (1D) surface defect on designer surface plasmon polaritons (designer SPPs) supported by a 1D metallic grating in THz domai...By using a finite difference time domain (FDTD) method, the effects of a one-dimensional (1D) surface defect on designer surface plasmon polaritons (designer SPPs) supported by a 1D metallic grating in THz domain are investigated. When the size of the defect is in a special range which is not too large, the designer SPPs reflected and scattered by the defect are weak enough to be neglected. The defect only induces a disturbance in the energy distribution of the designer SPP supported by the whole defect grating. If the defect size exceeds the said range, the reflecting and scattering are dominant in the influences of the defect on designer SPPs. Our analysis opens opportunities to control and direct designer SPPs by introducing a 1D defect, especially in low frequency domain.展开更多
Generalized impedance boundary conditions are employed to simplify the solution of the Sommerfeld half-space problem. An analytical expression is derived for the Hertz potential of a vertical electric dipole over the ...Generalized impedance boundary conditions are employed to simplify the solution of the Sommerfeld half-space problem. An analytical expression is derived for the Hertz potential of a vertical electric dipole over the earth’s surface, in which the earth is assumed to be a layered media or homogeneous dissipative half-space. A Sommerfeld type integral in the potential function is expressed as the sum of two parts: a zeroth order Hankel function and an absolutely convergent series of Bessel functions. In addition, two expressions in closed form are obtained as the far-field and near-field approximation of the present result.展开更多
It is well known that the macroscopic Maxwell’s equations can be obtained from the corresponding microscopic or atomic equations by a proper averaging process. The purpose of this paper is to present the macroscopic ...It is well known that the macroscopic Maxwell’s equations can be obtained from the corresponding microscopic or atomic equations by a proper averaging process. The purpose of this paper is to present the macroscopic Maxwell’s equations which are valid in all regions of space, including an interface between two different media; and the boundary conditions can naturally emerge from the macroscopic equations as an effect of average of the microscopic Maxwell’s equations. In addition, the application of the unit step functions and the Dirac delta function to our discussion not only permits great mathematical simplicity but also gives rise to convenient physical concepts for the description and representation of the actual fields in the vicinity of the interface.展开更多
The frequency selective surface (FSS) has been widely applied by means of its spatial frequency-filter characteristic, but it is always designed and used as a device with fixed frequency response. In order to tune the...The frequency selective surface (FSS) has been widely applied by means of its spatial frequency-filter characteristic, but it is always designed and used as a device with fixed frequency response. In order to tune the resonant frequency and switch the frequency channel, a scheme of mechanically tunable FSS is theoretically analyzed by using the method of Floquet's vector modes expansion and fields matching. A double-layer tunable FSS with dipole element can perform a dynamic range of resonant frequency covering whole X-band.展开更多
Polarization singularities in the near-field of Gaussian vortex beams diffracted by a circular aperture are studied by a rigorous electromagnetic theory. It is shown that there exist C-points and L-lines, which depend...Polarization singularities in the near-field of Gaussian vortex beams diffracted by a circular aperture are studied by a rigorous electromagnetic theory. It is shown that there exist C-points and L-lines, which depend on off-axis displacement parameters along the x and y directions, waist width, wavelength, and topological charge of the diffracted Gaussian vortex beam, as well as on propagation distance. The results are illustrated by numerical calculations.展开更多
Microwave remote sensing has become the primary means for sea-ice research, and has been supported by a great deal of field experiments and theoretical studies regarding sea-ice microwave scattering. However, these st...Microwave remote sensing has become the primary means for sea-ice research, and has been supported by a great deal of field experiments and theoretical studies regarding sea-ice microwave scattering. However, these studies have been barely carried in the Bohai Sea. The sea-ice microwave scattering mechanism was first developed for the thin sea ice with slight roughness in the Bohai Sea in the winter of 2012, and included the backscattering coefficients which were measured on the different conditions of three bands(L, C and X), two polarizations(HH and VV), and incident angles of 20° to 60°, using a ground-based scatterometer and the synchronous physical parameters of the sea-ice temperature, density, thickness, salinity, and so on. The theoretical model of the sea-ice electromagnetic scattering is obtained based on these physical parameters. The research regarding the sea-ice microwave scattering mechanism is carried out through two means, which includes the comparison between the field microwave scattering data and the simulation results of the theoretical model, as well as the feature analysis of the four components of the sea-ice electromagnetic scattering. It is revealed that the sea-ice microwave scattering data and the theoretical simulation results vary in the same trend with the incident angles. Also, there is a visible variant in the sensitivity of every component to the different bands.For example, the C and X bands are sensitive to the top surface, the X band is sensitive to the scatterers, and the L and C bands are sensitive to the bottom surface, and so on. It is suggested that the features of the sea-ice surfaces and scatterers can be retrieved by the further research in the future. This experiment can provide an experimental and theoretical foundation for research regarding the sea-ice microwave scattering characteristics in the Bohai Sea.展开更多
This article attempts to outline Paul C.Mocombe’s nominalism as highlighted in his theory of phenomenological structuralism(PS).Mocombe posits that the human mind or consciousness is presented with brute facts and th...This article attempts to outline Paul C.Mocombe’s nominalism as highlighted in his theory of phenomenological structuralism(PS).Mocombe posits that the human mind or consciousness is presented with brute facts and things of the multiverse,which it attempts to reify and universalize through concepts of language and mathematics.So,the facts and things of the world exist irrespective of the human mind,which simply highlights and categorizes them in order to experience being-in-the-world with others and things they encounter.展开更多
Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40 keV to 500 keV. As a specific feature, the output beam ener...Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40 keV to 500 keV. As a specific feature, the output beam energy spread is as low as 0.6% achieved with the internal discrete bunching method, which makes potential applications of RFQ feasible, such as accelerator mass spectrometry and ion implantation. Tolerances of the beam dynamics design are studied by means of changing the input beam parameters, and the results are quite satisfying. On the other hand, the L-IH-RFQ structure is employed, taking advantage of its mechanical stability and the absence of inter-electrode voltage asymmetry. Radio-frequency properties are studied and optimized for reducing power loss with Microwave Studio (MWS). Tuning of the field flatness and frequency is investigated in principle.展开更多
Accelerator mass spectrometry (AMS) is one of the most promising methods to detect minute amounts of 182Hf. However, the sensitivity of 5×10^-11 for ^182Hf/180Hf obtained previously by the AMS method at China I...Accelerator mass spectrometry (AMS) is one of the most promising methods to detect minute amounts of 182Hf. However, the sensitivity of 5×10^-11 for ^182Hf/180Hf obtained previously by the AMS method at China Institute of Atomic Energy (CIAE) cannot meet the requirement of some applications. We present some new improvements of measurement method for AMS measurement of 182Hf at the CIAE HI?13 tandem accelerator system. As a result, a sensitivity of 1.0×10^-11 for 182Hf/180Hf is achieved.展开更多
A 30-MeV femto-second electron linac is built at the Shanghai Institute of Applied Physics, which can produce high power, coherent THz undulator radiation. We report the experimental facility and measurement of the po...A 30-MeV femto-second electron linac is built at the Shanghai Institute of Applied Physics, which can produce high power, coherent THz undulator radiation. We report the experimental facility and measurement of the power, frequency spectrum. First experiments show the averaged power at THz to be about 20mW.展开更多
The full torus electromagnetic gyrokinetic particle simulations using the hybrid model with kinetic electrons in the presence of magnetic shear is presented.The fluid-kinetic electron hybrid model employed in this pap...The full torus electromagnetic gyrokinetic particle simulations using the hybrid model with kinetic electrons in the presence of magnetic shear is presented.The fluid-kinetic electron hybrid model employed in this paper improves numerical properties by removing the tearing mode,meanwhile,preserves both linear and nonlinear wave-particle resonances of electrons with Alfven wave and ion acoustic wave.展开更多
The conventional vector addition theorem is written in a compact notation.Then a new and succinct derivation of the vector addition theorem is presented thatis as close to the derivation of the scalar addition theorem...The conventional vector addition theorem is written in a compact notation.Then a new and succinct derivation of the vector addition theorem is presented thatis as close to the derivation of the scalar addition theorem. Newly derived expressionsin this new derivation are used to diagonalize the vector addition theorem. Thediagonal form of the vector addition theorem is important in the design of fast algorithmsfor computational wave physics such as computational electromagnetics andcomputational acoustics.展开更多
文摘The signs of the electric field markers in Figs.2 and 4 of the paper[Chin.Phys.B 32104211(2023)]have been corrected.These modifications do not affect the results derived in the paper.
基金Project supported by the Guangdong Innovative and Entrepreneurial Research Team Program (Grant No. 2016ZT06C594)the Science and Technology Project of Guangdong Province of China (Grant No. 2020B010190001)+1 种基金the National Key R&D Program of China (Grant No. 2018YFA0306200)the National Natural Science Foundation of China (Grant No. 11974119)。
文摘Atoms in the microscopic world are the basic building blocks of the macroscopic world. In this work, we construct an atomic-scale electromagnetic theory that bridges optics in the microscopic and macroscopic worlds. As the building block of the theory, we use the microscopic polarizability to describe the optical response of a single atom, solve the transport of electromagnetic wave through a single atomic layer under arbitrary incident angle and polarization of the light beam, construct the single atomic layer transfer matrix for light transport across the atomic layer. Based on this transfer matrix, we get the analytical form of the dispersion relation, refractive index, and transmission/reflection coefficient of the macroscopic medium. The developed theory can handle single-layer and few-layers of homogeneous and heterogeneous 2D materials, investigate homogeneous 2D materials with various vacancies or insertion atomic-layer defects, study compound 2D materials with a unit cell composed of several elements in both the lateral and parallel directions with respect to the light transport.
文摘It is currently believed that light quantum or the quantization of light energy is beyond classical physics, and the picture of wave-particle duality, which was criticized by Einstein but has attracted a number of experimental researches, is necessary for the description of light. It is shown in this paper, however, that the quantization of light energy in vacuum, which is the same as that in quantum electrodynamics, can be derived directly from the classical electromagnetic theory through the consideration of statistics based on classical physics. Therefore, the quantization of energy is an intrinsic property of light as a classical electromagnetic wave and has no need of being related to particles.
基金Supported by the National Nature Science Foundation of China (grant No. 30471384 )
文摘Many domestic and international scholars have done a wide range of researches on electromagnetic and technology and have made some achievements. Electromagnetic technology has been used in forest pests control as a convenient and high-efficient physics means. This article summaries the current study of the electromagnetic biological effect and introduces the appfication of microwave, pulsed electromagnetic field and electrostatic field to forest pests control. The research direction and prospect of the application of electromagnetic theory and technology to forest pests control arc also discussed.
文摘This paper presents the principle of electromagnetic missile from the mathematical point of view, and verifies rigorously that the radiating power over whole space is limited.
文摘In the course of designing and developing different-purpose electrodynamical devices,electromagnetic processes in movable and immovable media need to be calculated simultaneously.The solution for such tasks based on the electromagnetic field theory is associated with the emergence of significant theoretical and practical difficulties.The problems that arise during the calculation of electromagnetic processes in movable and immovable media of electrodynamical devices using the electromagnetic field theory are examined in this study.Improved approaches toward the calculation of electromagnetic processes in electrodynamical devices using Maxwell’s equations are suggested.Notably,calculating electromagnetic processes in movable and immovable media using Maxwell’s equations necessitates consideration of the systems of coordinates where the electromagnetic phenomena are analyzed.Theoretically substantiated methods of calculating electromagnetic processes in movable and immovable media based on the principles of electromagnetic field theory are proposed.The methods consider the systems of coordinates where the analysis of electromagnetic phenomena is conducted.The effectiveness of the suggested methods for example in calculating electromagnetic processes in movable and immovable media of the turbogenerator is illustrated.
文摘This article argues that the Haitian Vodou spirits(lwas)of fertility and death,Gede,do not promote homosexuality or the fluidity of sexuality in Haitian culture.The latter position is a Western reading of Gede grounded in postmodern and post-structural identity theorizing.Gede in Haitian ontology and epistemology is lwas of fertility and death not sexual identity confusion or fluidity.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10974063)the Research Foundation of Wuhan National Laboratory (Grant No. P080008)the National Basic Research Program of China (Grant No. 2007CB310403)
文摘By using a finite difference time domain (FDTD) method, the effects of a one-dimensional (1D) surface defect on designer surface plasmon polaritons (designer SPPs) supported by a 1D metallic grating in THz domain are investigated. When the size of the defect is in a special range which is not too large, the designer SPPs reflected and scattered by the defect are weak enough to be neglected. The defect only induces a disturbance in the energy distribution of the designer SPP supported by the whole defect grating. If the defect size exceeds the said range, the reflecting and scattering are dominant in the influences of the defect on designer SPPs. Our analysis opens opportunities to control and direct designer SPPs by introducing a 1D defect, especially in low frequency domain.
文摘Generalized impedance boundary conditions are employed to simplify the solution of the Sommerfeld half-space problem. An analytical expression is derived for the Hertz potential of a vertical electric dipole over the earth’s surface, in which the earth is assumed to be a layered media or homogeneous dissipative half-space. A Sommerfeld type integral in the potential function is expressed as the sum of two parts: a zeroth order Hankel function and an absolutely convergent series of Bessel functions. In addition, two expressions in closed form are obtained as the far-field and near-field approximation of the present result.
文摘It is well known that the macroscopic Maxwell’s equations can be obtained from the corresponding microscopic or atomic equations by a proper averaging process. The purpose of this paper is to present the macroscopic Maxwell’s equations which are valid in all regions of space, including an interface between two different media; and the boundary conditions can naturally emerge from the macroscopic equations as an effect of average of the microscopic Maxwell’s equations. In addition, the application of the unit step functions and the Dirac delta function to our discussion not only permits great mathematical simplicity but also gives rise to convenient physical concepts for the description and representation of the actual fields in the vicinity of the interface.
文摘The frequency selective surface (FSS) has been widely applied by means of its spatial frequency-filter characteristic, but it is always designed and used as a device with fixed frequency response. In order to tune the resonant frequency and switch the frequency channel, a scheme of mechanically tunable FSS is theoretically analyzed by using the method of Floquet's vector modes expansion and fields matching. A double-layer tunable FSS with dipole element can perform a dynamic range of resonant frequency covering whole X-band.
基金Project supported by the China Postdoctoral Science Foundation (Grant No. 2009450159)the Foundation of the State Key Laboratory of Optical Technologies for Micro-Frabrication and Micro-Engineering,Chinese Academy of Sciences (Grant No. KF001)
文摘Polarization singularities in the near-field of Gaussian vortex beams diffracted by a circular aperture are studied by a rigorous electromagnetic theory. It is shown that there exist C-points and L-lines, which depend on off-axis displacement parameters along the x and y directions, waist width, wavelength, and topological charge of the diffracted Gaussian vortex beam, as well as on propagation distance. The results are illustrated by numerical calculations.
基金The National Science Foundation for Young Scientists of China under contract No.41306193the National Special Research Fund for Non-Profit Marine Sector under of China under contract No.201105016the European Space Agency-Ministry of Science and Technology of the People’s Republic of China(ESA-MOST)Dragon 3 Cooperation Programme under contract No.10501
文摘Microwave remote sensing has become the primary means for sea-ice research, and has been supported by a great deal of field experiments and theoretical studies regarding sea-ice microwave scattering. However, these studies have been barely carried in the Bohai Sea. The sea-ice microwave scattering mechanism was first developed for the thin sea ice with slight roughness in the Bohai Sea in the winter of 2012, and included the backscattering coefficients which were measured on the different conditions of three bands(L, C and X), two polarizations(HH and VV), and incident angles of 20° to 60°, using a ground-based scatterometer and the synchronous physical parameters of the sea-ice temperature, density, thickness, salinity, and so on. The theoretical model of the sea-ice electromagnetic scattering is obtained based on these physical parameters. The research regarding the sea-ice microwave scattering mechanism is carried out through two means, which includes the comparison between the field microwave scattering data and the simulation results of the theoretical model, as well as the feature analysis of the four components of the sea-ice electromagnetic scattering. It is revealed that the sea-ice microwave scattering data and the theoretical simulation results vary in the same trend with the incident angles. Also, there is a visible variant in the sensitivity of every component to the different bands.For example, the C and X bands are sensitive to the top surface, the X band is sensitive to the scatterers, and the L and C bands are sensitive to the bottom surface, and so on. It is suggested that the features of the sea-ice surfaces and scatterers can be retrieved by the further research in the future. This experiment can provide an experimental and theoretical foundation for research regarding the sea-ice microwave scattering characteristics in the Bohai Sea.
文摘This article attempts to outline Paul C.Mocombe’s nominalism as highlighted in his theory of phenomenological structuralism(PS).Mocombe posits that the human mind or consciousness is presented with brute facts and things of the multiverse,which it attempts to reify and universalize through concepts of language and mathematics.So,the facts and things of the world exist irrespective of the human mind,which simply highlights and categorizes them in order to experience being-in-the-world with others and things they encounter.
基金Supported by the National Natural Science Foundation of China under Grant No 10775009.
文摘Beam dynamics and rf designs of a 104 MHz ladder type IH-RFQ (L-IH-RFQ) accelerator are finished at Peking University for the acceleration of 14C+ from 40 keV to 500 keV. As a specific feature, the output beam energy spread is as low as 0.6% achieved with the internal discrete bunching method, which makes potential applications of RFQ feasible, such as accelerator mass spectrometry and ion implantation. Tolerances of the beam dynamics design are studied by means of changing the input beam parameters, and the results are quite satisfying. On the other hand, the L-IH-RFQ structure is employed, taking advantage of its mechanical stability and the absence of inter-electrode voltage asymmetry. Radio-frequency properties are studied and optimized for reducing power loss with Microwave Studio (MWS). Tuning of the field flatness and frequency is investigated in principle.
基金Supported by the Foundation of China Academy of Engineering Physics under Grant No 10576040, and the National Natural Science Foundation of China under Grant No 10705054.
文摘Accelerator mass spectrometry (AMS) is one of the most promising methods to detect minute amounts of 182Hf. However, the sensitivity of 5×10^-11 for ^182Hf/180Hf obtained previously by the AMS method at China Institute of Atomic Energy (CIAE) cannot meet the requirement of some applications. We present some new improvements of measurement method for AMS measurement of 182Hf at the CIAE HI?13 tandem accelerator system. As a result, a sensitivity of 1.0×10^-11 for 182Hf/180Hf is achieved.
文摘A 30-MeV femto-second electron linac is built at the Shanghai Institute of Applied Physics, which can produce high power, coherent THz undulator radiation. We report the experimental facility and measurement of the power, frequency spectrum. First experiments show the averaged power at THz to be about 20mW.
基金This work is supported by Department of Energy(DOE)Cooperative Agreement No.DE-FC02-04ER54796Grant No.DE-FC02-06ER54860in part by SciDAC GPS,GSEP,and CPES centers。
文摘The full torus electromagnetic gyrokinetic particle simulations using the hybrid model with kinetic electrons in the presence of magnetic shear is presented.The fluid-kinetic electron hybrid model employed in this paper improves numerical properties by removing the tearing mode,meanwhile,preserves both linear and nonlinear wave-particle resonances of electrons with Alfven wave and ion acoustic wave.
基金Part of this work was done when the author was a Cheng Tsang Man Visiting Professor at Nanyang Technological University,Singapore.This work is dedicated to the memory of Professor Y.T.Lo.Partial support by AFOSR MURI grant FA9550-04-1-0326WC is gratefully acknowledged.Feedback from an anonymous reviewer for improving the manuscript is gratefully acknowledged.
文摘The conventional vector addition theorem is written in a compact notation.Then a new and succinct derivation of the vector addition theorem is presented thatis as close to the derivation of the scalar addition theorem. Newly derived expressionsin this new derivation are used to diagonalize the vector addition theorem. Thediagonal form of the vector addition theorem is important in the design of fast algorithmsfor computational wave physics such as computational electromagnetics andcomputational acoustics.