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Radiation of a TM mode from an open end of a three-layer dielectric capillary
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作者 Sergey NGalyamin Alexandr MAltmark 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期311-318,共8页
Modern trends in beam-driven radiation sources include the interaction of Cherenkov wakefields in open-ended circular waveguides with complicated dielectric linings, with a three-layer dielectric capillary recently pr... Modern trends in beam-driven radiation sources include the interaction of Cherenkov wakefields in open-ended circular waveguides with complicated dielectric linings, with a three-layer dielectric capillary recently proposed to reduce radiation divergence being a representative example [Opt. Lett. 45 5416(2020)]. We present a rigorous approach that allows for an analytical description of the electromagnetic processes that occur when the structure is excited by a single waveguide TM mode. In other words, the corresponding canonical waveguide diffraction problem is solved in a rigorous formulation. This is a continuation of our previous papers which considered simpler cases with a homogeneous or two-layer dielectric filling. Here we use the same analytical approach based on the Wiener–Hopf–Fock technique and deal with the more complicated case of a three-layer dielectric lining. Using the obtained rigorous solution, we discuss the possibility of manipulating the far-field radiation pattern using a third layer made of a low permittivity material. 展开更多
关键词 diffraction radiation open-ended waveguide Wiener–Hopf technique Cherenkov radiation
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Wave Radiation and Diffraction by A Two-Dimensional Floating Body with An Opening Near A Side Wall 被引量:6
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作者 张洪生 周华伟 《China Ocean Engineering》 SCIE EI CSCD 2013年第4期437-450,共14页
The radiation and diffraction problem of a two-dimensional rectangular body with an opening floating on a semi- infinite fluid domain of finite water depth is analysed based on the linearized velocity potential theory... The radiation and diffraction problem of a two-dimensional rectangular body with an opening floating on a semi- infinite fluid domain of finite water depth is analysed based on the linearized velocity potential theory through an analytical solution procedure. The expressions for potentials are obtained by the method of variation separation, in which the unknown coefficients are determined by the boundary condition and matching requirement on the interface. The effects of the position of the hole and the gap between the body and side wall on hydrodynamic characteristics are investigated. Some resonance is observed like piston motion in a moon pool and sloshing in a closed tank because of the existence of restricted fluid domains. 展开更多
关键词 wave radiation and diffraction floating body with an opening side wall variable separation method domain decomposition
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Hot deformation of Mg-Y-Zn alloy with a low content of the LPSO phase studied by in-situ synchrotron radiation diffraction 被引量:5
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作者 Klaudia Horváth Fekete Daria Drozdenko +5 位作者 Jan Capek Kristián Máthis Domonkos Tolnai Andreas Stark Gerardo Garcés Patrik Dobron 《Journal of Magnesium and Alloys》 SCIE 2020年第1期199-209,共11页
The compressive deformation behavior of the extruded WZ42(Mg98.5Y1Zn0.5 in at.%)magnesium alloy containing a low amount of long-period stacking ordered(LPSO)phase was studied by in-situ synchrotron radiation diffracti... The compressive deformation behavior of the extruded WZ42(Mg98.5Y1Zn0.5 in at.%)magnesium alloy containing a low amount of long-period stacking ordered(LPSO)phase was studied by in-situ synchrotron radiation diffraction technique.Tests were conducted at temperatures between room temperature and 350℃.Detailed microstructure investigation was provided by scanning electron microscopy,particularly the backscattered electron imaging and electron backscatter diffraction technique.The results show that twinning lost its dominance and kinking of the LPSO phase became more pronounced with increasing deformation temperature.No cracks of the LPSO phase and no debonding r at the interface between the LPSO phase and the Mg matrix were observed at temperatures above 200℃.At 350℃,the LPSO phase lost its strengthening effect and the deformation of the alloy was mainly realized by the dynamic recrystallization of the Mg matrix. 展开更多
关键词 Magnesium alloy LPSO phase KINKING High temperature Synchrotron radiation diffraction
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High pressure x-ray diffraction techniques with synchrotron radiation 被引量:6
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作者 刘景 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第7期9-21,共13页
This article summarizes the developments of experimental techniques for high pressure x-ray diffraction(XRD) in diamond anvil cells(DACs) using synchrotron radiation. Basic principles and experimental methods for ... This article summarizes the developments of experimental techniques for high pressure x-ray diffraction(XRD) in diamond anvil cells(DACs) using synchrotron radiation. Basic principles and experimental methods for various diffraction geometry are described, including powder diffraction, single crystal diffraction, radial diffraction, as well as coupling with laser heating system. Resolution in d-spacing of different diffraction modes is discussed. More recent progress, such as extended application of single crystal diffraction for measurements of multigrain and electron density distribution, timeresolved diffraction with dynamic DAC and development of modulated heating techniques are briefly introduced. The current status of the high pressure beamline at BSRF(Beijing Synchrotron Radiation Facility) and some results are also presented. 展开更多
关键词 high pressure x-ray diffraction synchrotron radiation diamond anvil cell
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Radiation and diffraction analysis of a cylindrical body with a moon pool 被引量:7
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作者 周华伟 张洪生 《Journal of Hydrodynamics》 SCIE EI CSCD 2013年第2期196-204,共9页
An analytical solution is presented for the radiation and the diffraction of a cylindrical body with a moon pool floating on the surface of water with a finite depth. The expressions for the potentials are obtained by... An analytical solution is presented for the radiation and the diffraction of a cylindrical body with a moon pool floating on the surface of water with a finite depth. The expressions for the potentials are obtained by the method of separation of variables, and the unknown coefficients are determined by the boundary conditions and the matching requirements on the interface. The effects of the moon pool on the hydrodynamic characteristics of the body are investigated. Some peaks are observed on the curves of the added mass and damping coefficients, corresponding to the resonant frequencies of the moon pool. The internal free surface moves like a piston at a certain low resonant frequency. 展开更多
关键词 radiation and diffraction cylindrical body moon pool variable separation method resonant frequencies
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High temperature mechanical behaviour of Mg-6Zn-1Y alloy with 1 wt.% calcium addition:Reinforcing effect due to I-(Mg3Zn6Yi)and Mg6Zn3Ca2 phases 被引量:6
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作者 J.Medina G.Garces +3 位作者 P.Perez A.Stark N.Schell P.Adeva 《Journal of Magnesium and Alloys》 SCIE EI CAS 2020年第4期1047-1060,共14页
The infiuence of small calcium additions on the high-temperature mechanical behaviour in an extruded Mg-6Zn-l Y(wt.%)alloy reinforced by the I-phase has been investigated.Calcium promotes the formation of the intermet... The infiuence of small calcium additions on the high-temperature mechanical behaviour in an extruded Mg-6Zn-l Y(wt.%)alloy reinforced by the I-phase has been investigated.Calcium promotes the formation of the intermetallic Mg6Zn3Ca2 phase instead of 1-phase,which results in a noticeable improvement of the yield strength and ultimate tensile strength of the alloy above 100℃.The strength of the alloys was analysed taking into account the contribution due to the grain size,the crystallographic texture and the volume fraction and nature of second phase particles.In situ synchrotron radiation diffraction experiments have been used to evaluate the load partitioning between the magnesium matrix and the second phase particles(1-and MgeZgCa?phases)in both alloys.The load transfer from the magnesium matrix towards the MgeZihCa?phase is markedly more effective than that for the I-phase over the entire temperature range,especially at 200°C,temperature at which the reinforcement effect of the I-phase is null. 展开更多
关键词 Magnesium alloys I-phase Synchrotron radiation diffraction High temperature mechanical properties.
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Wave radiation and diffraction by a floating rectangular structure with an opening at its bottom in oblique seas 被引量:3
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作者 杨小岩 张洪生 李海涛 《Journal of Hydrodynamics》 SCIE EI CSCD 2017年第6期1054-1066,共13页
The radiation and the diffraction of linear waves by a rectangular structure with an opening at its bottom floating in oblique seas of finite depth are investigated. Analytical expressions for the radiated potentials ... The radiation and the diffraction of linear waves by a rectangular structure with an opening at its bottom floating in oblique seas of finite depth are investigated. Analytical expressions for the radiated potentials and the diffracted potential are obtained by use of the method of separation of variables and the eigenfunction expansion method, with the unknown coefficients being determined by the boundary conditions and the matching requirement on the interface. The hydrodynamic coefficients and the wave excitation forces are verified using the symmetry properties of coupled hydrodynamic coefficients and one specific example investigated previously. By use of the present analytical-numerical solution, the influences of the angle of incidence, the width of the opening on the wave forces and the hydrodynamic coefficients are investigated. It is also found that in the oblique sea the external excitation frequency that can lead to the resonance of a rectangular tank depends on the wave direction and the wave number of the incident wave. 展开更多
关键词 Oblique-wave radiation and diffraction floating structure with an opening analytical-numerical solution hydrodynamiccoefficient wave excitation force
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Interaction of Oblique Waves and A Rectangular Structure with An Opening Near A Vertical Wall 被引量:1
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作者 ZHANG Hong-sheng ZHENG Bi-fang YANG Xiao-yan 《China Ocean Engineering》 SCIE EI CSCD 2017年第2期220-229,共10页
With the method of separation of variables and the eigenfunction expansion employed, an analytical solution is presented for the radiation and diffraction of a rectangular structure with an opening near a vertical wal... With the method of separation of variables and the eigenfunction expansion employed, an analytical solution is presented for the radiation and diffraction of a rectangular structure with an opening near a vertical wall in oblique seas, in which the unknown coefficients are determined by the boundary conditions and matching requirement on the interface. The effects of the width of the opening and the angle of incidence on the hydrodynamic characteristics of a rectangular structure with an opening near a vertical wall are mainly studied. The comparisons of the calculation results with wall-present and with wall-absent are also made. The results indicate that the variation trends of the heave added mass and excitation force with wall-present are almost the same as those with wall-absent, and that the peak values in the former case are obviously larger than those in the latter due to the reflection of the vertical wall. 展开更多
关键词 wave radiation and diffraction rectangular structure OPENING oblique incidence vertical wall analytical solution hydrodynamic characteristics comparison
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ON VELOCITY POTENTIALS DUE TO PULSATING PRESSURE DISTRIBUTIONS ON THE FREE SURFACE OF INFINITE-DEPTH WATERS AND THE RADIATION CONDITIONS FOR SECOND-ORDER DIFFRACTION PROBLEMS
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作者 Miao Guo-ping Liu Ying-zhong Shanghai Jiao Tong University,Shanghai,P.R.China 《Journal of Hydrodynamics》 SCIE EI CSCD 1989年第4期103-114,共12页
In the present paper,two-and three-dimensional velocity potentials generated by pulsating pressure distributions of infinite extent on the free surface of infinite-depth waters are strictly derived based on special ca... In the present paper,two-and three-dimensional velocity potentials generated by pulsating pressure distributions of infinite extent on the free surface of infinite-depth waters are strictly derived based on special cases of concentrated pulsating pressure.The far-field asymptotic behaviour of the potentials and the radiation conditions to be satisfied by them are discussed. It is proved in a general sense that the potentials should be composed of a forced wave component,a free wave component and a local disturbance component.The radiation condition of the forced wave component should correspond to the far-field asymptotic behaviour of the pressure distribution,Hence,the formulation of radiation conditions for the second-order diffraction potentials has theoretically become clear,The radiation conditions for two-and three-dimensional problems are explicitly given in the paper. 展开更多
关键词 ON VELOCITY POTENTIALS DUE TO PULSATING PRESSURE DISTRIBUTIONS ON THE FREE SURFACE OF INFINITE-DEPTH WATERS AND THE radiation CONDITIONS FOR SECOND-ORDER diffraction PROBLEMS 于七 body
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Interface regulation of Cu_(2)Se via Cu–Se–C bonding for superior lithium-ion batteries
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作者 Kefu Zhu Shiqiang Wei +13 位作者 Quan Zhou Shuangming Chen Yunxiang Lin Pengjun Zhang Yuyang Cao Changda Wang Yixiu Wang Yujian Xia Dengfeng Cao Zeinab Mohamed Xin Guo Xiya Yang Xiaojun Wu Li Song 《Nano Research》 SCIE EI CSCD 2023年第2期2421-2427,共7页
Transition metal selenides have aroused great attention in recent years due to their high theoretical capacity.However,the huge volume fluctuation generated by conversion reaction during the charge/discharge process r... Transition metal selenides have aroused great attention in recent years due to their high theoretical capacity.However,the huge volume fluctuation generated by conversion reaction during the charge/discharge process results in the significant electrochemical performance reduction.Herein,the carbon-regulated copper(I)selenide(Cu_(2)Se@C)is designed to significantly promote the interface stability and ion diffusion for selenide electrodes.The systematic X-ray spectroscopies characterizations and density functional theory(DFT)simulations reveal that the Cu–Se–C bonding forming on the surface of Cu2Se not only improves the electronic conductivity of Cu_(2)Se@C but also retards the volume change during electrochemical cycling,playing a pivotal role in interface regulation.Consequently,the storage kinetics of Cu_(2)Se@C is mainly controlled by the capacitance process diverting from the ion diffusion-controlled process of Cu2Se.When employed this distinctive Cu_(2)Se@C as anode active material in Li coin cell configuration,the ultrahigh specific capacity of 810.3 mA·h·g^(−1)at 0.1 A·g^(−1)and the capacity retention of 83%after 1,500 cycles at 5 A·g^(−1)is achieved,implying the best Cu-based Li^(+)-storage capacity reported so far.This strategy of heterojunction combined with chemical bonding regulation opens up a potential way for the development of advanced electrodes for battery storage systems. 展开更多
关键词 Cu–Se–C bonding interface regulation lithium-ion battery X-ray absorption spectroscopy(XAS) operando synchrotron radiation X-ray diffraction(SRXRD)
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A Universal Blown Film Apparatus for in Situ X-ray Measurements
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作者 Rui Zhang 纪又新 +5 位作者 Qian-lei Zhang Jian-zhu Ju Ali Sarmad Li-fu Li Hao-yuan Zhao 李良彬 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2017年第12期1508-1516,共9页
A setup of blown film machine combined with in situ synchrotron radiation X-ray diffraction measurements and infrared temperature testing is reported to study the structure evolution of polymers during film blowing. T... A setup of blown film machine combined with in situ synchrotron radiation X-ray diffraction measurements and infrared temperature testing is reported to study the structure evolution of polymers during film blowing. Two homemade auto-lifters are constructed and placed under the blown machine at each end of the beamline platform which move up and down with a speed of 0.05 mm/s bearing the 200 kg weight machine. Therefore, structure development and temperature changes as a function of position on the film bubble can be obtained. The blown film machine is customized to be conveniently installed with precise servo motors and can adjust the processing parameters in a wide range. Meanwhile, the air ring has been redesigned in order to track the structure information of the film bubble immediately after the melt being extruded out from the die exit. Polyethylene(PE) is selected as a model system to verify the feasibility of the apparatus and the in situ experimental techniques. Combining structure information provided by the WAXD and SAXS and the actual temperature obtained from the infrared probe, a full roadmap of structure development during film blowing is constructed and it is helpful to explore the molecular mechanism of structure evolution behind the film blowing processing, which is expected to lead to a better understanding of the physics in polymer processing. 展开更多
关键词 Blown film machine Synchrotron radiation X-ray diffraction In situ measurement Structure evolution
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Establishing two-stage interaction between fly ash and NaOH by X-ray and infrared analyses
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作者 Bhagwanjee JHA Nevin KOSHY Devendra Narain SINGH 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2015年第2期216-221,共6页
The interaction of the fly ash and NaOH, in an open reflux hydrothermal system at 100℃, has been explored by several researchers and formation of fly ash zeolites has been confirmed based on the X-ray diffraction ana... The interaction of the fly ash and NaOH, in an open reflux hydrothermal system at 100℃, has been explored by several researchers and formation of fly ash zeolites has been confirmed based on the X-ray diffraction analysis of the residues. However, this method does not reveal much about the characteristic transitions (viz. elemental, electro-negativity and cation exchange capa- city) of the residues. In this situation, resorting to Fourier transform-infrared radiation (FT-IR) spectroscopy on the residues obtained from two-stage hydrothermal treatment process, described in this manuscript, appears to be a novel idea to establish transitions in chemical bonds (viz., -Si- OH-AI-, OH-Na, OH-A1-), crystallinity and cation exchange capacity of these residues. Based on extensive studies, it has been demonstrated that FT-IR spectroscopy is extremely useful for 1) detection of chemical bonds in the residues, 2) evaluation of zeolites in the residues and 3) also establishing the superiority of the two-stage interac- tion of the fly ash with NaOH for synthesizing better fly ash zeolites (viz., Na-P1 and Hydroxysodalte) as compared to those obtained from the conventional single-stage treatment of the fly ash. 展开更多
关键词 hydrothermal treatment alkali activation flyash zeolites X-ray diffraction (XRD) and Fourier transform-infrared radiation (FT-IR) spectroscopy
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