Formation of a quasi-stationary discharge or quasi-stationary emission mode in the explosive-emission electron sources is related to the current limitation resulting from the emissive ability saturation of cathode pla...Formation of a quasi-stationary discharge or quasi-stationary emission mode in the explosive-emission electron sources is related to the current limitation resulting from the emissive ability saturation of cathode plasma with its expansion. The paper shows that in the process of the discharge current stabilization in the explosive-emission sources with the point- or blade-type emitters the essential role belongs to the electron beam space charge. Availability of the space charge results in limitation of the current growth velocity at the initial discharge phase and, hence, restricts the emissive ability of the cathode plasma and contributes to its saturation. In the vacuum diodes with multiemitter cathodes, the space charge availability increases the cathode operation stability and can provide obtaining of quasi-stationary beam current values or close to them resulting in formation of a plasma emission surface at the cathode close to the continuous one.展开更多
CMEs(Coronal Mass Ejections) are an important means of energy release in the solar corona.Solar Polar Orbit Radio Telescope(SPORT) is a mission being proposed for observing the propagation of interplanetary CMEs from ...CMEs(Coronal Mass Ejections) are an important means of energy release in the solar corona.Solar Polar Orbit Radio Telescope(SPORT) is a mission being proposed for observing the propagation of interplanetary CMEs from solar polar orbit.The main payload onboard SPORT is a synthetic aperture interferometric radiometer,which receives radio emission of interplanetary CMEs. It is identified that there are mainly three radio emission mechanisms of CMEs,i.e.,bremsstrahlung, gyrosynchrotron emission and plasma emission.Among these emission types,bremsstrahlung emission is the main emission mechanism of the high-density plasma clouds of interplanetary CMEs.Gyrosynchrotron emission is the continuous emission generated by high-energy electrons from CMEs, while plasma emission is the main mechanism of transient radio bursts from CMEs.In this paper,the gyrosynchrotron emission of interplanetary CMEs is focused on.Firstly,the mechanism of gyrosynchrotron emission is reviewed.Secondly,a review of the physical parameter models of background solar wind and interplanetary CMEs is presented.After these,the brightness temperature and polarization of gyrosynchrotron emission of interplanetary CMEs are calculated and analyzed.Finally, the detectability of gyrosynchrotron emission of interplanetary CMEs by radio meters is discussed briefly.展开更多
O437／／TN249 2005053443 影响单电子非线性汤姆孙散射因素的研究=Parameters that influence the nonlinear Thomsom scattering of single electrons in high-intensity laser fields[刊,中]／郑君(中科 院物理所光物理开放实验室．...O437／／TN249 2005053443 影响单电子非线性汤姆孙散射因素的研究=Parameters that influence the nonlinear Thomsom scattering of single electrons in high-intensity laser fields[刊,中]／郑君(中科 院物理所光物理开放实验室．北京(100080)),盛政明…∥ 物理学报．-2005,54(3)．-1018-1035 应用电子汤姆孙散射的经典理论,通过理论分析和计 算机模拟,研究了超短超强激光脉冲作用下电子产生的辐 射脉冲的性质。计算表明,在这种情况下,电子的辐射通 常以阿秒脉冲列的形式。展开更多
Inductively coupled plasma optical emission spectrometric approach（1CP-OES） is used to determine the potassium content as principal component in pyrotechnic compositions used for fireworks and firecrackers. Element ...Inductively coupled plasma optical emission spectrometric approach（1CP-OES） is used to determine the potassium content as principal component in pyrotechnic compositions used for fireworks and firecrackers. Element of potassium is conunonly found in potassium nitrate and potassium perchlorate in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that potassium nitrate content in pyrotechnics is between 10% to 60% and the potassium perchlorate content is between 20% to 70%,which counted in the content of potassium element is between 4% to 23%. Concept of this method： considering the weight of the sample is 400rag,constant volume is 1L and the concentration of potassium is between 10 mg/L to 90 mg/L in sample solution, the determination scope of the method for the potassium content would be between 1% to 23%.Further experiments proved that the fitting correlation coefficient of potassium calibration curve is 0.9997 or higher, recovery is 89.15%-100.23%.The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.展开更多
A plasma spectroscopy experiment is described and its performances are given, ways oI excltauon u^ttc~,t tc~,,,,,~ ,,, free-burning plasma at atmospheric pressure is analyzed in detail. The fixed-grating spectrograph ...A plasma spectroscopy experiment is described and its performances are given, ways oI excltauon u^ttc~,t tc~,,,,,~ ,,, free-burning plasma at atmospheric pressure is analyzed in detail. The fixed-grating spectrograph PGS-2 Carl Zeiss Jena is actually a variation on the very first spectrometer design, where photo-plate was replaced with a detector array of PIXIS-Roper Scientific camera. Abilities of the system are analyzed and its limitations are determined.展开更多
Inductively coupled plasma optical emission spectrometric approach（ICP-OES）is used to determine the magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrack...Inductively coupled plasma optical emission spectrometric approach（ICP-OES）is used to determine the magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrackers. Elements of magnesium and aluminum are commonly found in aluminum powder or magnesium-aluminum alloy powder in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that the magnesium content in pyrotechnics is between 8% to 30% and the aluminum content is between 8% to 35%（roughly）.Concept of this method： suppose the weight of the sample is 400rag,constant volume is IL and the concentlation of magnesium and aluminum is between 12mg/L to 160mg/L in sample solution, the determination scope of the method for magnesium and aluminum content would be between 3% to 40%.Further experiments proved that the fitting correlation coefficient of the magnesium calibration curve is 0.9999 or higher, recovery is 101.01% -101.96%.The fitting correlation coefficient of the aluminum calibration curve is 0.9999 or higher, recovery is 99.36%-103.07%. The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.展开更多
文摘Formation of a quasi-stationary discharge or quasi-stationary emission mode in the explosive-emission electron sources is related to the current limitation resulting from the emissive ability saturation of cathode plasma with its expansion. The paper shows that in the process of the discharge current stabilization in the explosive-emission sources with the point- or blade-type emitters the essential role belongs to the electron beam space charge. Availability of the space charge results in limitation of the current growth velocity at the initial discharge phase and, hence, restricts the emissive ability of the cathode plasma and contributes to its saturation. In the vacuum diodes with multiemitter cathodes, the space charge availability increases the cathode operation stability and can provide obtaining of quasi-stationary beam current values or close to them resulting in formation of a plasma emission surface at the cathode close to the continuous one.
基金Supported by the National Natural Science Foundation of China(No.40574070)China Post-doctor Foundation
文摘CMEs(Coronal Mass Ejections) are an important means of energy release in the solar corona.Solar Polar Orbit Radio Telescope(SPORT) is a mission being proposed for observing the propagation of interplanetary CMEs from solar polar orbit.The main payload onboard SPORT is a synthetic aperture interferometric radiometer,which receives radio emission of interplanetary CMEs. It is identified that there are mainly three radio emission mechanisms of CMEs,i.e.,bremsstrahlung, gyrosynchrotron emission and plasma emission.Among these emission types,bremsstrahlung emission is the main emission mechanism of the high-density plasma clouds of interplanetary CMEs.Gyrosynchrotron emission is the continuous emission generated by high-energy electrons from CMEs, while plasma emission is the main mechanism of transient radio bursts from CMEs.In this paper,the gyrosynchrotron emission of interplanetary CMEs is focused on.Firstly,the mechanism of gyrosynchrotron emission is reviewed.Secondly,a review of the physical parameter models of background solar wind and interplanetary CMEs is presented.After these,the brightness temperature and polarization of gyrosynchrotron emission of interplanetary CMEs are calculated and analyzed.Finally, the detectability of gyrosynchrotron emission of interplanetary CMEs by radio meters is discussed briefly.
文摘O437／／TN249 2005053443 影响单电子非线性汤姆孙散射因素的研究=Parameters that influence the nonlinear Thomsom scattering of single electrons in high-intensity laser fields[刊,中]／郑君(中科 院物理所光物理开放实验室．北京(100080)),盛政明…∥ 物理学报．-2005,54(3)．-1018-1035 应用电子汤姆孙散射的经典理论,通过理论分析和计 算机模拟,研究了超短超强激光脉冲作用下电子产生的辐 射脉冲的性质。计算表明,在这种情况下,电子的辐射通 常以阿秒脉冲列的形式。
文摘Inductively coupled plasma optical emission spectrometric approach（1CP-OES） is used to determine the potassium content as principal component in pyrotechnic compositions used for fireworks and firecrackers. Element of potassium is conunonly found in potassium nitrate and potassium perchlorate in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that potassium nitrate content in pyrotechnics is between 10% to 60% and the potassium perchlorate content is between 20% to 70%,which counted in the content of potassium element is between 4% to 23%. Concept of this method： considering the weight of the sample is 400rag,constant volume is 1L and the concentration of potassium is between 10 mg/L to 90 mg/L in sample solution, the determination scope of the method for the potassium content would be between 1% to 23%.Further experiments proved that the fitting correlation coefficient of potassium calibration curve is 0.9997 or higher, recovery is 89.15%-100.23%.The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.
文摘A plasma spectroscopy experiment is described and its performances are given, ways oI excltauon u^ttc~,t tc~,,,,,~ ,,, free-burning plasma at atmospheric pressure is analyzed in detail. The fixed-grating spectrograph PGS-2 Carl Zeiss Jena is actually a variation on the very first spectrometer design, where photo-plate was replaced with a detector array of PIXIS-Roper Scientific camera. Abilities of the system are analyzed and its limitations are determined.
文摘Inductively coupled plasma optical emission spectrometric approach（ICP-OES）is used to determine the magnesium and aluminum content as principal components in pyrotechnic compositions used for fireworks and firecrackers. Elements of magnesium and aluminum are commonly found in aluminum powder or magnesium-aluminum alloy powder in pyrotechnic compositions in fireworks and firecrackers. Statistical analysis shows that the magnesium content in pyrotechnics is between 8% to 30% and the aluminum content is between 8% to 35%（roughly）.Concept of this method： suppose the weight of the sample is 400rag,constant volume is IL and the concentlation of magnesium and aluminum is between 12mg/L to 160mg/L in sample solution, the determination scope of the method for magnesium and aluminum content would be between 3% to 40%.Further experiments proved that the fitting correlation coefficient of the magnesium calibration curve is 0.9999 or higher, recovery is 101.01% -101.96%.The fitting correlation coefficient of the aluminum calibration curve is 0.9999 or higher, recovery is 99.36%-103.07%. The allowable differential value is 0.4% between two single tests under repeatable conditions. This method can completely satisfy the requirements of the fireworks and firecrackers industry with high accuracy and good precision.
