An approximation method based on Regge behavior is presented. This new methodrelates the reduced cross section derivative and the structure function Regge behavior at low x.With the use of this approximation method, t...An approximation method based on Regge behavior is presented. This new methodrelates the reduced cross section derivative and the structure function Regge behavior at low x.With the use of this approximation method, the C and λ parameters are calcuiated from the HERAreduced cross section data taken at low-x. Also, we calculate the structure functions F_2(x, Q~2)even for low-x values, which have not been investigated. To test the validity of calculatedstructure functions, we find the gluon distribution function in the Leading order approximationbased on Regge behaviour of structure function and compare to the NLO QCD fit to H1 data and NLOparton distribution function.展开更多
We measured the resonant Raman spectra of all-trans-β-carotene in solvents with different densities and concentrations at different temperatures. The results demonstrated that the Raman scattering cross section （RSC...We measured the resonant Raman spectra of all-trans-β-carotene in solvents with different densities and concentrations at different temperatures. The results demonstrated that the Raman scattering cross section （RSCS） of short-chain polymer all-trans-β-carotene is extremely high in liquid. Resonance and strong coherent weakly damped CC bond vibrating properties play important roles under these conditions. Coherent weakly damped CC bond vibration strength is associated with molecular ordered structure. All-trans-β-carotene has highly ordered structure and strong coherent weakly damped CC bond vibrating properties, which lead to large RSCS in the solvent with large density and low concentration at low temperature.展开更多
With 3D orthogonal and pseudo-orthogonal weaves, woven sructures with lengthwise and widthwise changing cross section on one side or both sides of the structure can be constructed. The weave formation and the looming ...With 3D orthogonal and pseudo-orthogonal weaves, woven sructures with lengthwise and widthwise changing cross section on one side or both sides of the structure can be constructed. The weave formation and the looming draft creation are discussed in this paper which can be used as references to manufacture woven preforms with changing cross sections.展开更多
The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing ...The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing geotechnical works(ISO 23469)and code for seismic design of urban rail transit structures(GB 50909-2014).However,there are some obvious limitations in the application of RDM.Springs and the shear stress of the soil could be approximately evaluated for the structures having a simple cross section,such as rectangular and circular structures.It is necessary to propose simplified seismic analysis methods for structures with complex cross sections.This paper refers to the idea of RDM and proposes three generalized response displacement methods(GRDM).In GRDM1,a part of the soil surrounding a structure is selected to generate a generalized underground structure with a rectangular cross section,and the same analysis model as RDM is applied to analyze the responses of the structure.In GRDM2,a hollow soil model without a generalized structure is used to compute the equivalent load caused by the relative displacement of the soil,and the soil-structure interaction model is applied to calculate the responses of the structure.In GRDM3,a continuous soil model is applied to compute the equivalent load caused by the relative displacement and shear stress of the soil,and the soil-structure interaction model is applied to analyze the responses of the structure,which is the same as the model used in GRDM2.The time-history analysis method(THAM)is used to evaluate the accuracy of the proposed simplified methods.Results show that the error of GRDM1 is about 20%,while the error is only 5%for GRDM2 and GRDM3.Among the three proposed methods,GRDM3 has obvious advantages regarding calculation efficiency and accuracy.Therefore,it is recommended to use GRDM3 for the seismic response analysis of underground structures that have conventional simple or complex cross sections.展开更多
This paper is an effort to extract the structure function, the EMC ratio, and the lepton scattering cross section in the convolution nuclear theory framework for 4He and 12C nuclei. We suppose that, in conventional ap...This paper is an effort to extract the structure function, the EMC ratio, and the lepton scattering cross section in the convolution nuclear theory framework for 4He and 12C nuclei. We suppose that, in conventional approach, based on harmonic oscillator model, one could consider for a nucleus shell different hw?parameters which are associated with the square root of the mean radius of the nucleus shells. We use GRV free nucleon structure function, which has good agreement with the proton and neutron structure function, extracted from experimental results. In addition, the lepton scattering cross sections of 4He and 12C nuclei are calculated in energy higher than 1 GeV. The extracted results show good agreement with experimental data.展开更多
In order to solve the thickness dependence of plasma absorption of electromagnetic waves and further reduce the backward radar scattering cross section(RCS)of the target,we designed a novel composite structure of a me...In order to solve the thickness dependence of plasma absorption of electromagnetic waves and further reduce the backward radar scattering cross section(RCS)of the target,we designed a novel composite structure of a metasurface and plasma.A metasurface with three absorption peaks is designed by means of an equivalent circuit based on an electromagnetic resonance type metamaterial absorber.The reflection and absorption of the composite structure are numerically and experimentally verified.The finite integration method was used to simulate a composite structure of finite size to obtain the RCS.The experimental measurements of electromagnetic wave reflection were conducted by a vector network analyzer(Keysight N5234A)and horn antennas,etc.The research showed that the absorption capacity of this composite structure was substantially improved compared to either the plasma or the metasurface,and it is more convenient for application due to its low plasma thickness requirement and easy fabrication.展开更多
A one-dimensional modified integral equation for electromagnetic scattering from a metallic concentric disc-ring structure is derived by using Fourier expansion and separating the contribution of charge density from c...A one-dimensional modified integral equation for electromagnetic scattering from a metallic concentric disc-ring structure is derived by using Fourier expansion and separating the contribution of charge density from conventional EFIE. In the case of normal incidence, the derived equation is very simple and easy to be solved numerically regardless of the electric dimension of the structure. The comparison between the data of RCS of a disc by using this method and analytical method shows the effectiveness of this approach. Numerical results are also given for current distributions and the scattered fields for a disc-ring structure.展开更多
A kind of novel electromagnetic structure of Cassini cross section is proposed and simulation is implemented with business microwave soft CST based on finite integral technique （FIT）. The electromagnetic field mode ...A kind of novel electromagnetic structure of Cassini cross section is proposed and simulation is implemented with business microwave soft CST based on finite integral technique （FIT）. The electromagnetic field mode type of Cassini wave-guide belongs to TE, and the electromagnetic field intensity is stronger near the neck region than at other areas. For Cassini electromagnetic patches and lumped elements, the radar cross section （RCS） is smaller around 7 GHz with -30.85 dBsm, and the absorbing property is better around 13 GHz with 4.56 dBsm difference of RCS from comparing of pure medium. For novel radiation structure of Cassini cross-section patches, the electromagnetic field value is larger in the neck areas of two half patches. At last, the potential application and development of Cassini oval structure are put forward in the electromagnetic stealth technology and antennae design.展开更多
The excess pion inside the nucleus could change not only nucleons structure function, but also electron scattering cross section from nuclei. In this paper, we calculate pionic contribution in nuclear structure functi...The excess pion inside the nucleus could change not only nucleons structure function, but also electron scattering cross section from nuclei. In this paper, we calculate pionic contribution in nuclear structure functions of 3He and 3H nuclei and the differential cross sections of electron scattering from these nuclei. At first, we calculate the Fermi motion and binding energy contribution as an important nuclear medium effect in scattering cross sections and then we add pionic contribution to structure functions and differential cross sections of electron scattering from these nuclei that the Fermi motion and binding energy are considered.展开更多
The synchrotron radiation angle-resolved photoemission data of K3C60 single crystal film are analyzed, aiming at the photoionization cross-sections of the LUMO, HOMO and HOMO-1 bands in low photon energy region （14.5...The synchrotron radiation angle-resolved photoemission data of K3C60 single crystal film are analyzed, aiming at the photoionization cross-sections of the LUMO, HOMO and HOMO-1 bands in low photon energy region （14.5--27.5 eV）. Many fine structures of the HOMO/HOMO-1 intensity ratios are observed, which support the general validity of a quantum chemistry model. However, the experimental data and the theoretical results have some disagreement in the energy positions and magnitudes of the fine structures, and the disagreement is more outstanding than the case of pure C60. So the photoemission data of K3C60 afford valuable experimental reference to further theoretical developments. The LUMO cross-section data, which cannot be discussed with the quantum chemistry description due to strong solid state effects, are also reported for further studies.展开更多
文摘An approximation method based on Regge behavior is presented. This new methodrelates the reduced cross section derivative and the structure function Regge behavior at low x.With the use of this approximation method, the C and λ parameters are calcuiated from the HERAreduced cross section data taken at low-x. Also, we calculate the structure functions F_2(x, Q~2)even for low-x values, which have not been investigated. To test the validity of calculatedstructure functions, we find the gluon distribution function in the Leading order approximationbased on Regge behaviour of structure function and compare to the NLO QCD fit to H1 data and NLOparton distribution function.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10774057 and 10974067)the Graduate Innovation Fund of Jilin University,China (Grant No. 20101046)
文摘We measured the resonant Raman spectra of all-trans-β-carotene in solvents with different densities and concentrations at different temperatures. The results demonstrated that the Raman scattering cross section （RSCS） of short-chain polymer all-trans-β-carotene is extremely high in liquid. Resonance and strong coherent weakly damped CC bond vibrating properties play important roles under these conditions. Coherent weakly damped CC bond vibration strength is associated with molecular ordered structure. All-trans-β-carotene has highly ordered structure and strong coherent weakly damped CC bond vibrating properties, which lead to large RSCS in the solvent with large density and low concentration at low temperature.
文摘With 3D orthogonal and pseudo-orthogonal weaves, woven sructures with lengthwise and widthwise changing cross section on one side or both sides of the structure can be constructed. The weave formation and the looming draft creation are discussed in this paper which can be used as references to manufacture woven preforms with changing cross sections.
基金National Natural Science Foundation of China under Grant No.52108453Natural Science Foundation of Jiangxi Province of China under Grant No.20212BAB214014+1 种基金National Key R&D Program of China under Grant No.2018YFC1504305Joint Funds of the National Natural Science Foundation of China under Grant No.U1839201。
文摘The response displacement method(RDM)is recommended for the seismic analysis of underground structures in the transverse direction for many codes,including bases for design of structures-seismic actions for designing geotechnical works(ISO 23469)and code for seismic design of urban rail transit structures(GB 50909-2014).However,there are some obvious limitations in the application of RDM.Springs and the shear stress of the soil could be approximately evaluated for the structures having a simple cross section,such as rectangular and circular structures.It is necessary to propose simplified seismic analysis methods for structures with complex cross sections.This paper refers to the idea of RDM and proposes three generalized response displacement methods(GRDM).In GRDM1,a part of the soil surrounding a structure is selected to generate a generalized underground structure with a rectangular cross section,and the same analysis model as RDM is applied to analyze the responses of the structure.In GRDM2,a hollow soil model without a generalized structure is used to compute the equivalent load caused by the relative displacement of the soil,and the soil-structure interaction model is applied to calculate the responses of the structure.In GRDM3,a continuous soil model is applied to compute the equivalent load caused by the relative displacement and shear stress of the soil,and the soil-structure interaction model is applied to analyze the responses of the structure,which is the same as the model used in GRDM2.The time-history analysis method(THAM)is used to evaluate the accuracy of the proposed simplified methods.Results show that the error of GRDM1 is about 20%,while the error is only 5%for GRDM2 and GRDM3.Among the three proposed methods,GRDM3 has obvious advantages regarding calculation efficiency and accuracy.Therefore,it is recommended to use GRDM3 for the seismic response analysis of underground structures that have conventional simple or complex cross sections.
文摘This paper is an effort to extract the structure function, the EMC ratio, and the lepton scattering cross section in the convolution nuclear theory framework for 4He and 12C nuclei. We suppose that, in conventional approach, based on harmonic oscillator model, one could consider for a nucleus shell different hw?parameters which are associated with the square root of the mean radius of the nucleus shells. We use GRV free nucleon structure function, which has good agreement with the proton and neutron structure function, extracted from experimental results. In addition, the lepton scattering cross sections of 4He and 12C nuclei are calculated in energy higher than 1 GeV. The extracted results show good agreement with experimental data.
基金financially supported by National Natural Science Foundation of China(No.12175050)the Foundation of National Key Laboratory of Electromagnetic Environment of China(No.202101003)。
文摘In order to solve the thickness dependence of plasma absorption of electromagnetic waves and further reduce the backward radar scattering cross section(RCS)of the target,we designed a novel composite structure of a metasurface and plasma.A metasurface with three absorption peaks is designed by means of an equivalent circuit based on an electromagnetic resonance type metamaterial absorber.The reflection and absorption of the composite structure are numerically and experimentally verified.The finite integration method was used to simulate a composite structure of finite size to obtain the RCS.The experimental measurements of electromagnetic wave reflection were conducted by a vector network analyzer(Keysight N5234A)and horn antennas,etc.The research showed that the absorption capacity of this composite structure was substantially improved compared to either the plasma or the metasurface,and it is more convenient for application due to its low plasma thickness requirement and easy fabrication.
文摘A one-dimensional modified integral equation for electromagnetic scattering from a metallic concentric disc-ring structure is derived by using Fourier expansion and separating the contribution of charge density from conventional EFIE. In the case of normal incidence, the derived equation is very simple and easy to be solved numerically regardless of the electric dimension of the structure. The comparison between the data of RCS of a disc by using this method and analytical method shows the effectiveness of this approach. Numerical results are also given for current distributions and the scattered fields for a disc-ring structure.
文摘A kind of novel electromagnetic structure of Cassini cross section is proposed and simulation is implemented with business microwave soft CST based on finite integral technique （FIT）. The electromagnetic field mode type of Cassini wave-guide belongs to TE, and the electromagnetic field intensity is stronger near the neck region than at other areas. For Cassini electromagnetic patches and lumped elements, the radar cross section （RCS） is smaller around 7 GHz with -30.85 dBsm, and the absorbing property is better around 13 GHz with 4.56 dBsm difference of RCS from comparing of pure medium. For novel radiation structure of Cassini cross-section patches, the electromagnetic field value is larger in the neck areas of two half patches. At last, the potential application and development of Cassini oval structure are put forward in the electromagnetic stealth technology and antennae design.
文摘The excess pion inside the nucleus could change not only nucleons structure function, but also electron scattering cross section from nuclei. In this paper, we calculate pionic contribution in nuclear structure functions of 3He and 3H nuclei and the differential cross sections of electron scattering from these nuclei. At first, we calculate the Fermi motion and binding energy contribution as an important nuclear medium effect in scattering cross sections and then we add pionic contribution to structure functions and differential cross sections of electron scattering from these nuclei that the Fermi motion and binding energy are considered.
基金Supported by National Natural Science Foundation of China (10674115)Beijing Synchrotron Radiation Facility
文摘The synchrotron radiation angle-resolved photoemission data of K3C60 single crystal film are analyzed, aiming at the photoionization cross-sections of the LUMO, HOMO and HOMO-1 bands in low photon energy region （14.5--27.5 eV）. Many fine structures of the HOMO/HOMO-1 intensity ratios are observed, which support the general validity of a quantum chemistry model. However, the experimental data and the theoretical results have some disagreement in the energy positions and magnitudes of the fine structures, and the disagreement is more outstanding than the case of pure C60. So the photoemission data of K3C60 afford valuable experimental reference to further theoretical developments. The LUMO cross-section data, which cannot be discussed with the quantum chemistry description due to strong solid state effects, are also reported for further studies.
