The cylindrical virtual cathode reflex triode is a new type of pulsed hard X-ray load,which has the advantages of simple structure,high radiation conversion efficiency,and simplicity in seriesparallel operation.This p...The cylindrical virtual cathode reflex triode is a new type of pulsed hard X-ray load,which has the advantages of simple structure,high radiation conversion efficiency,and simplicity in seriesparallel operation.This paper presents a method to reduce the impedance of the triode using a multiring cathode.The average electric field on the ring-cathode emission surface is enhanced due to edge effect,and the beam intensity is greatly increased in proportion to the square of the electric field strength.Multi-ring cathode is used to enlarge the emission area.Therefore,the reflex triode can work at lower impedance and generate a stronger beam under the same anode-cathode gap.In addition,the electric field enhancement of the cathode reduces the cathode emission stabilization time and enhances the operation stability of the triode.The effects of parameters such as ring width and ring gap on the triode impedance are simulated and studied.The cathode emission stabilization time and the X-ray conversion efficiency are compared.The design basis of cathode structure parameters and the impedance control method of the cylindrical virtual cathode reflex triode are given according to the simulations.展开更多
In this paper is determined the volume conductivity of thin polymeric films using the corona triode method, when the current through the sample exhibits a quadratic dependence on the grid potential. Based on the exper...In this paper is determined the volume conductivity of thin polymeric films using the corona triode method, when the current through the sample exhibits a quadratic dependence on the grid potential. Based on the experimental data, for the first time, an effective methodology for the determination of volume conductivity, graphically and analytically, is composed. The results obtained by the proposed analytical formula, for polypropylene and Trespaphan, with two different configurations of structures, are closely similar to the graphical method results. In addition, the satisfying accordance of our results, with the results, found out with the consulted literature, obtained by the “static” methods, confirms the accuracy of the proposed methodology, for the determination of volume conductivity of thin polymeric films, using the corona triode.展开更多
A triode extraction system is designed for a dual hollow cathode ion source being developed at the Institute of Heavy Ion Physics, Peking University. Basic parameters of the plasma are selected after examining the ope...A triode extraction system is designed for a dual hollow cathode ion source being developed at the Institute of Heavy Ion Physics, Peking University. Basic parameters of the plasma are selected after examining the operation principle of the ion source, then the triode extraction system is designed and optimized by using software PBGUNS （for Particle Beam GUN Simulations）. The physical design of the system is given in this paper.展开更多
Based on our study on field emission from multi-walled carbon nanotubes （MWNTs）, we experimentally manufactured field emission display （FED） triode with a MWNTs cold cathode, and demonstrated an excellent performa...Based on our study on field emission from multi-walled carbon nanotubes （MWNTs）, we experimentally manufactured field emission display （FED） triode with a MWNTs cold cathode, and demonstrated an excellent performance of MWNTs as field emitters. The measured luminance of the phosphor screens was 1.8 × 10^3 cd/m^2 for green light. The emission is stable with a fluctuation of only 1.5% at an average current of 260 μA.展开更多
The Fermat–Pramanik series are like below: .The mathematical principle has been established by factorization principle. The Fermat-Pramanik tree can be grown. It produces branched Fermat-Pramanik series using same pr...The Fermat–Pramanik series are like below: .The mathematical principle has been established by factorization principle. The Fermat-Pramanik tree can be grown. It produces branched Fermat-Pramanik series using same principle making Fermat-Pramanik chain. Branched chain can be propagated at any point of the main chain with indefinite length using factorization principle as follows: Same principle is applicable for integer solutions of A<sup>M</sup>+B<sup>2</sup>=C<sup>2</sup>which produces series of the type . It has been shown that this equation is solvable with N{A, B, C, M}. where , , M=M<sub>1</sub>+M<sub>2</sub> and M<sub>1</sub>>M<sub>2</sub>. Subsequently, it has been shown that using M= M<sub>1</sub>+M<sub>2</sub>+M<sub>3</sub>+... The combinations of Ms should be taken so that the values of both the parts (C<sub>n</sub>+B<sub>n</sub>) and (C<sub>n</sub>-B<sub>n</sub>) should be even or odd for obtaining Z{B,C}. Hence, it has been shown that the Fermat triple can generate a) Fermat-Pramanik multiplate, b) Fermat-Pramanik Branched multiplate and c) Fermat-Pramanik deductive series. All these formalisms are useful for development of new principle of cryptography. .展开更多
In this paper we determine for the first time the volume conductivity of polyethylene (of 40 μm and 50 μm thickness), using the positive corona triode. A general theory of flowing of the current through the sample, ...In this paper we determine for the first time the volume conductivity of polyethylene (of 40 μm and 50 μm thickness), using the positive corona triode. A general theory of flowing of the current through the sample, when it depends linearly on the grid potential, is formulated. A concrete methodology for the definition of volume conductivity is composed. The volume conductivity of polyethylene lies within the interval: . These results obtained using the corona triode are closely similar to those obtained using the standardized “static” methods, thus showing its superiority to the “dynamic” method of electronic radiation.展开更多
This paper describes the fabrication of backlight units（BLUs） for a liquid crystal display（LCD） based on a novel planar-gate electron source with patterned carbon nanotubes（CNTs） formed by electrophoretic deposi...This paper describes the fabrication of backlight units（BLUs） for a liquid crystal display（LCD） based on a novel planar-gate electron source with patterned carbon nanotubes（CNTs） formed by electrophoretic deposition. The electric field distributions and electron trajectories of this triode structure are simulated according to Ansys software.The device structure is optimized by supporting numerical simulation.The field emission results show that the emission current depends strongly on the cathode-gate gap and the gate voltage.Direct observation of the luminous images on a phosphor screen reveals that the electron beams undergo a noticeable expansion along the lateral direction with increasing gate voltage,which is in good agreement with the simulation results.The luminous efficiency and luminance of the fabricated device reaches 49.1 lm/W and 5500 cd/m^2,respectively.All results indicate that the novel planar-gate electron source with patterned CNTs may lead to practical applications for an electron source based on a flat lamp for BLUs in LCD.展开更多
基金supported by National Natural Science Foundation of China(Nos.12027811 and 12275222)。
文摘The cylindrical virtual cathode reflex triode is a new type of pulsed hard X-ray load,which has the advantages of simple structure,high radiation conversion efficiency,and simplicity in seriesparallel operation.This paper presents a method to reduce the impedance of the triode using a multiring cathode.The average electric field on the ring-cathode emission surface is enhanced due to edge effect,and the beam intensity is greatly increased in proportion to the square of the electric field strength.Multi-ring cathode is used to enlarge the emission area.Therefore,the reflex triode can work at lower impedance and generate a stronger beam under the same anode-cathode gap.In addition,the electric field enhancement of the cathode reduces the cathode emission stabilization time and enhances the operation stability of the triode.The effects of parameters such as ring width and ring gap on the triode impedance are simulated and studied.The cathode emission stabilization time and the X-ray conversion efficiency are compared.The design basis of cathode structure parameters and the impedance control method of the cylindrical virtual cathode reflex triode are given according to the simulations.
文摘In this paper is determined the volume conductivity of thin polymeric films using the corona triode method, when the current through the sample exhibits a quadratic dependence on the grid potential. Based on the experimental data, for the first time, an effective methodology for the determination of volume conductivity, graphically and analytically, is composed. The results obtained by the proposed analytical formula, for polypropylene and Trespaphan, with two different configurations of structures, are closely similar to the graphical method results. In addition, the satisfying accordance of our results, with the results, found out with the consulted literature, obtained by the “static” methods, confirms the accuracy of the proposed methodology, for the determination of volume conductivity of thin polymeric films, using the corona triode.
基金Supported by National Natural Science Foundation of China (10775011)
文摘A triode extraction system is designed for a dual hollow cathode ion source being developed at the Institute of Heavy Ion Physics, Peking University. Basic parameters of the plasma are selected after examining the operation principle of the ion source, then the triode extraction system is designed and optimized by using software PBGUNS （for Particle Beam GUN Simulations）. The physical design of the system is given in this paper.
基金This work was supported by the Science and Technology Foundation of Education Ministry of China under Grant No. 205091.
文摘Based on our study on field emission from multi-walled carbon nanotubes （MWNTs）, we experimentally manufactured field emission display （FED） triode with a MWNTs cold cathode, and demonstrated an excellent performance of MWNTs as field emitters. The measured luminance of the phosphor screens was 1.8 × 10^3 cd/m^2 for green light. The emission is stable with a fluctuation of only 1.5% at an average current of 260 μA.
文摘The Fermat–Pramanik series are like below: .The mathematical principle has been established by factorization principle. The Fermat-Pramanik tree can be grown. It produces branched Fermat-Pramanik series using same principle making Fermat-Pramanik chain. Branched chain can be propagated at any point of the main chain with indefinite length using factorization principle as follows: Same principle is applicable for integer solutions of A<sup>M</sup>+B<sup>2</sup>=C<sup>2</sup>which produces series of the type . It has been shown that this equation is solvable with N{A, B, C, M}. where , , M=M<sub>1</sub>+M<sub>2</sub> and M<sub>1</sub>>M<sub>2</sub>. Subsequently, it has been shown that using M= M<sub>1</sub>+M<sub>2</sub>+M<sub>3</sub>+... The combinations of Ms should be taken so that the values of both the parts (C<sub>n</sub>+B<sub>n</sub>) and (C<sub>n</sub>-B<sub>n</sub>) should be even or odd for obtaining Z{B,C}. Hence, it has been shown that the Fermat triple can generate a) Fermat-Pramanik multiplate, b) Fermat-Pramanik Branched multiplate and c) Fermat-Pramanik deductive series. All these formalisms are useful for development of new principle of cryptography. .
文摘In this paper we determine for the first time the volume conductivity of polyethylene (of 40 μm and 50 μm thickness), using the positive corona triode. A general theory of flowing of the current through the sample, when it depends linearly on the grid potential, is formulated. A concrete methodology for the definition of volume conductivity is composed. The volume conductivity of polyethylene lies within the interval: . These results obtained using the corona triode are closely similar to those obtained using the standardized “static” methods, thus showing its superiority to the “dynamic” method of electronic radiation.
基金supported by the National Natural Science Fotndation of China(Nos.61106053,61101169)the Technology Projects of Department of Education,Fujian Province,China(No.JA11014)
文摘This paper describes the fabrication of backlight units（BLUs） for a liquid crystal display（LCD） based on a novel planar-gate electron source with patterned carbon nanotubes（CNTs） formed by electrophoretic deposition. The electric field distributions and electron trajectories of this triode structure are simulated according to Ansys software.The device structure is optimized by supporting numerical simulation.The field emission results show that the emission current depends strongly on the cathode-gate gap and the gate voltage.Direct observation of the luminous images on a phosphor screen reveals that the electron beams undergo a noticeable expansion along the lateral direction with increasing gate voltage,which is in good agreement with the simulation results.The luminous efficiency and luminance of the fabricated device reaches 49.1 lm/W and 5500 cd/m^2,respectively.All results indicate that the novel planar-gate electron source with patterned CNTs may lead to practical applications for an electron source based on a flat lamp for BLUs in LCD.
