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A Flux Ratio Independent of the Permanent Charge in PNP Models
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作者 Guojian Lin 《Journal of Applied Mathematics and Physics》 2023年第1期1-12,共12页
PNP models with an arbitrary number of positively charged ion species and one negatively charged ion species are studied in this paper under the assumption that positively charged ion species have the same valence and... PNP models with an arbitrary number of positively charged ion species and one negatively charged ion species are studied in this paper under the assumption that positively charged ion species have the same valence and the permanent charge is a piecewise constant function. The permanent charge plays the key role in many functions of an ion channel, such as selectivity and gating. In this paper, using the geometric singular perturbation theory, a flux ratio independent of the permanent charge is proved. 展开更多
关键词 PNP Model The Permanent charge Ionic Flow
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Battery Management System with State ofCharge Indicator for Electric Vehicles 被引量:9
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作者 孙逢春 张承宁 郭海涛 《Journal of Beijing Institute of Technology》 EI CAS 1998年第2期166-171,共6页
Aim To research and develop a battery management system(BMS)with the state of charge(SOC)indicator for electric vehicles (EVs).Methods On the basis of analyzing the electro-chemical characteristics of lead-acid. batte... Aim To research and develop a battery management system(BMS)with the state of charge(SOC)indicator for electric vehicles (EVs).Methods On the basis of analyzing the electro-chemical characteristics of lead-acid. battery, the state of charge indicator for lead-acid battery was developed by means of an algorithm based on combination of ampere-hour, Peukert's equation and open-voltage method with the compensation of temperature,aging,self- discharging,etc..Results The BMS based on this method can attain an accurate surplus capa- city whose error is less than 5% in static experiments.It is proved by experiments that the BMS is reliable and can give the driver an accurate surplus capacity,precisely monitor the individual battery modules as the same time,even detect and warn the problems early,and so on. Conclusion A BMS can make the energy of the storage batteries used efficiently, develop the batteries cycle life,and increase the driving distance of EVs. 展开更多
关键词 electric vehicle (EV) the battery management system (BMS) the stage of charge (SOC)indicator lead-acid battery
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Effects of ion-ion correlations on surface charge inversion in mixture electrolyte solutions 被引量:1
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作者 Tan Qiyan Kan Yajing +1 位作者 Zhao Gutian Chen Yunfei 《Journal of Southeast University(English Edition)》 EI CAS 2020年第3期285-291,共7页
As the structure of electrical double layer(EDL)is crucial for the transport properties of ions in micro/nanochannels,to demonstrate the effects of the ion-ion correlations on EDL structures in mixture electrolyte sol... As the structure of electrical double layer(EDL)is crucial for the transport properties of ions in micro/nanochannels,to demonstrate the effects of the ion-ion correlations on EDL structures in mixture electrolyte solutions,the interaction forces between two mica surfaces immersed in different volume fractions of LaCl3/KCl and LaCl3/MgCl2 mixture solutions with a total ionic strength of 10^-4 mol/L were measured using a surface forces apparatus(SFA).The results reveal that the surface charge of mica surfaces can be inversed at a critical concentration of La^3+ions in electrolyte solutions,due to the correlations between La^3+ions.The addition of monovalent has negligible effects on ion-ion correlations,while the charge inversion was slightly suppressed by introducing the divalent ions.The mechanism of charge inversion in mixture electrolyte solutions was analyzed based on the strongly correlated liquid(SCL)theory.These findings provide implications for understanding the effects of ion-ion correlations on EDL structures,surface charge properties,and ion transportation. 展开更多
关键词 ion-ion correlations charge inversion mixture electrolyte solutions surface forces apparatus
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Modulation and control of DNA charge inversion
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作者 王艳伟 杨光参 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第12期7-17,共11页
DNA is one of most important biological polyelectrolytes, which is negatively charged in physiological condition. Most of Its charge is neutralized by attracting cations in solution. In some conditions, the effective ... DNA is one of most important biological polyelectrolytes, which is negatively charged in physiological condition. Most of Its charge is neutralized by attracting cations in solution. In some conditions, the effective charge of DNA switches its sign from negative to positive, implying charge inversion of DNA. The underlying microscopic mechanism of the counterintuitive phenomenon is still not fully understood although specific chemical affinity and electrostatic ion correlation are considered as two possible driving forces. In this review, we present some recent experimental progress in the modulation and control of DNA charge by single molecular techniques. It has been shown that DNA charge inversion can be modulated bidirectionly by decreasing or increasing the dielectric constant of solution to make the electrophoretic mobility of DNA increase from a negative value to a positive value. In this meanwhile, charge inversion and condensation of DNA in solution of trivalent and quadrivalent counterions are significantly influenced by pH value of the solution. When mixing quadrivalent counterion with mono-, di-and tri-valent counterions in solution, suppression and promotion of DNA charge inversion can be observed. In addition, hydrophobic effect can play an important role in DNA charge inversiton and compaction. We show that the organic monovalent ions of tetraphenyl chloride arsenic (Ph4As+) can induce DNA compaction and even invert its electrophoretic mobility. Thus, hydrophobic effect can be the main driving force of DNA charge inversion and compaction by the organic monovalent ion. 展开更多
关键词 charge inversion COUNTERIONS dielectric constant pH value HYDROPHOBICITY
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Bright hybrid white light-emitting quantum dot device with direct charge injection into quantum dot
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作者 曹进 谢婧薇 +4 位作者 魏翔 周洁 陈超平 王子兴 田哲圭 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第12期514-519,共6页
A bright white quantum dot light-emitting device (white-QLED) with 4-[4-(1-phenyl-lH-benzo[d]imidazol-2- yl)phenyl]-2- [3-(tri-phenylen-2-yl)phen-3-yl]quinazoline deposited on a thin film of mixed green/red-QDs ... A bright white quantum dot light-emitting device (white-QLED) with 4-[4-(1-phenyl-lH-benzo[d]imidazol-2- yl)phenyl]-2- [3-(tri-phenylen-2-yl)phen-3-yl]quinazoline deposited on a thin film of mixed green/red-QDs as a bilayer emitter is fabricated. The optimized white-QLED exhibits a turn-on voltage of 3.2 V and a maximum brightness of 3660 cd/m2 @8 V with the Commission Internationale de l'Eclairage (CIE) chromaticity in the region of white light. The ultra-thin layer of QDs is proved to be critical for the white light generation in the devices. Excitation mechanism in the white-QLEDs is investigated by the detailed analyses of electroluminescence (EL) spectral and the fluorescence lifetime of QDs. The results show that charge injection is a dominant mechanism of excitation in the white-QLED. 展开更多
关键词 quantum dot light-emitting devices WHITE ultra-thin film charge injection
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Characterization of Interface Charge in NbAlO/AlGaN/GaN MOSHEMT with Different NbAlO Thicknesses
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作者 冯倩 杜锴 +2 位作者 代波 董良 冯庆 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第1期137-139,共3页
We investigate the influence of interface charge on electrical performance of NbAIO/A1GaN/GaN metal-oxide- semiconductor high electron mobility transistors (MOSHEMTs). Through C-V measurements and simulations, we fi... We investigate the influence of interface charge on electrical performance of NbAIO/A1GaN/GaN metal-oxide- semiconductor high electron mobility transistors (MOSHEMTs). Through C-V measurements and simulations, we find that the donor-type interface fixed charge density Qit of 2.2 × 10^13 cm^-2 exists at the NbA10/A1GaN interface, which induces the shift of the threshold voltage much more negative. Furthermore, a trap density of approximately 0.43 × 10^13-1.14 ×10^13 cm^-2 eV^-1 is obtained at the NaA10/AlGaN interface, which is consistent with the frequency-dependent capacitance and conductance measurement results. 展开更多
关键词 ALGAN Characterization of interface charge in NbAlO/AlGaN/GaN MOSHEMT with Different NbAlO Thicknesses
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20 MHz Switched-Current Sample-and-Hold Circuit with Low Charge Injection
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作者 高岑 姚素英 高静 《Transactions of Tianjin University》 EI CAS 2013年第1期47-52,共6页
A switched-current sample-and-hold circuit with low charge injection was proposed. To obtain low noise and charge injection, the zero-voltage switching was used to remove the signal-dependent charge injection, and the... A switched-current sample-and-hold circuit with low charge injection was proposed. To obtain low noise and charge injection, the zero-voltage switching was used to remove the signal-dependent charge injection, and the signal-independent charge injection was reduced by removing the feed-through voltage from the input port of the memory transistor directly. This current sample-and-hold circuit was implemented using CMOS 180 nm 1.8 V technology. For a 0.8 MHz sinusoidal signal input, the simulated signal-to-noise and distortion ratio and total harmonic distortion were improved from 53.74 dB and -51.24 dB to 56.53 dB and -54.36 dB at the sampling rate of 20 MHz respectively, with accuracy of 9.01 bit and power consumption of 0.44 mW. 展开更多
关键词 charge injection current-mode circuit sample-and-hold switched-current
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Experimental investigation of penetration performance of shaped charge into concrete targets 被引量:12
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作者 Cheng Wang Tianbao Ma Jianguo Ning 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2008年第3期345-349,共5页
In order to develop a tandem warhead that can effectively destroy concrete targets, this paper explores the penetration performance of shaped charges with different cone angles and liner materials into concrete target... In order to develop a tandem warhead that can effectively destroy concrete targets, this paper explores the penetration performance of shaped charges with different cone angles and liner materials into concrete targets by means of experiments. The penetration process and the destruction mechanism of concrete targets by shaped charges and kinetic energy projectiles are analyzed and compared. Experimental results suggest that both kinetic energetic projectile and shaped charge are capable of destroying concrete targets, but the magnitudes of damage are different. Compared with a kinetic energy projectile, a shaped charge has more significant effect of penetration into the target, and causes very large spalling area. Hence, a shaped charge is quite suitable for first-stage charge of tandem warhead. It is also found that, with the increase of shaped charge liner cone angle, the depth of penetration decreases gradually while the hole diameter becomes larger. Penetration depth with copper liner is larger than of aluminum liner but hole diameter is relatively smaller, and the shaped charge with steel liner is between the above two cases. The shaped charge with a cone angle of 100° can form a jet projectile charge (JPC). With JPC, a hole with optimum depth and diameter on concrete targets can be formed, which guarantees that the second-stage warhead smoothly penetrates into the hole and explodes at the optimum depth to achieve the desired level of destruction in concrete targets. 展开更多
关键词 Shaped charge JPC Kinetic energy projectile Concrete PENETRATION
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Study on orientation fracture blasting with shaped charge in rock 被引量:9
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作者 Yong Luo Zhaowu Shen 《Journal of University of Science and Technology Beijing》 CSCD 2006年第3期193-198,共6页
On the basis of the theories of mechanics of explosive and rock fracture mechanics, the mechanism of crack initiation and its expansion of directional fracture controlled blasting with shaped charges in rock were stud... On the basis of the theories of mechanics of explosive and rock fracture mechanics, the mechanism of crack initiation and its expansion of directional fracture controlled blasting with shaped charges in rock were studied, then the blasting parameters were designed and tested by a model test in laboratory and field experiment. The experimental and test results showed that the energy from blasting is directionally concentrated for the cumulative action. The directional expansion of cracks is satisfactory, the results of the model test and field test suggested that the orientation fracture blasting with shaped charge is a good means of excavating tunnels or cutting rock. 展开更多
关键词 explosive mechanics fracture mechanics orientation fracture blasting shaped charge model test
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Role of on-board discharge in shock wave drag reduction and plasma cloaking 被引量:6
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作者 邱孝明 唐德礼 +2 位作者 孙爱萍 刘万东 曾学军 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第1期186-192,共7页
In the present paper, a physical model is proposed for reducing the problem of the drag reduction of an attached bow shock around the nose of a high-speed vehicle with on-board discharge, to the problem of a balance b... In the present paper, a physical model is proposed for reducing the problem of the drag reduction of an attached bow shock around the nose of a high-speed vehicle with on-board discharge, to the problem of a balance between the magnetic pressure and gas pressure of plane shock of a partially ionized gas consisting of the environmental gas around the nose of the vehicle and the on-board discharge-produced plasma. The relation between the shock strength and the discharge-induced magnetic pressure is studied by means of a set of one-fluid, hydromagnetic equations reformed for the present purpose, where the discharge-induced magnetic field consists of the electron current (produced by the discharge)-induced magnetic field and the partially ionized gas flow-induced one. A formula for the relation between the above parameters is derived. It shows that the discharge-induced magnetic pressure can minimize the shock strength, successfully explaining the two recent experimental observations on attached bow shock mitigation and elimination in a supersonic flow during on-board discharge [Phys. Plasmas 9 (2002) 721 and Phys. Plasmas 7 (2000) 1345]. In addition, the formula implies that the shock elimination leaves room for a layer of higher-density plasma rampart moving around the nose of the vehicle, being favourable to the plasma radar cloaking of the vehicle. The reason for it is expounded. 展开更多
关键词 attached bow shock and magnetohydrodynamic (MHD) drag reduction on-board dis- charges plasma cloaking MHD and fluid equation
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The Origin of the Color Charge into Quarks 被引量:3
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作者 Giovanni Guido 《Journal of High Energy Physics, Gravitation and Cosmology》 2019年第1期1-34,共34页
Showing the origin of the mass in an additional coupling between field quantum oscillators, we formulate a hypothesis of a geometrical structure of the oscillators of “fields-particles”. In this way, we define the p... Showing the origin of the mass in an additional coupling between field quantum oscillators, we formulate a hypothesis of a geometrical structure of the oscillators of “fields-particles”. In this way, we define the possible structure of quarks and hadrons (as the proton). This hypothesis is reasonable if one admits field oscillators composed by sub-oscillators at semi-quantum (IQuO) and in which a degree of internal freedom is definable. Using the IQuO model, we find the origin of the sign of electric charge in to particles and, in quarks, the isospin, the strangeness and colour charge. Finally, we formulate the structure of the gluons and the variation modality of the colour charge in quarks. 展开更多
关键词 Massive Coupling “Aureus” Ratio Geometrical Structure IQuO Semi-Quantum Sub-Oscillator Entangled QUANTUM Vacuum Electric charge ISOSPin STRANGENESS COLOR GLUON
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Study on linear shaped charge in penetrating rock 被引量:1
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作者 Luo Yong 《Engineering Sciences》 EI 2008年第2期50-54,共5页
Based on the action mechanism of linear shaped charge( LSC ), penetration performance of LSC on rock was studied. The optimal standoff and the vertex angle of LSC were studied and determined by lab experiments. Thro... Based on the action mechanism of linear shaped charge( LSC ), penetration performance of LSC on rock was studied. The optimal standoff and the vertex angle of LSC were studied and determined by lab experiments. Through cutting sand-cement grout samples, the spacing interval of boreholes can approach 17.5 times of the bore-hole' s diameter, and the result of the directional expansion of crack is satisfactory. The result of field experiment indicates cutting effect is very good, the ruggedness in fracture plane is less than 50 mm, the rate of half-hole marks is nearly 100 % , and the crack inspection shows that there is no damage in the internal of the cutting part. All these suggest that the orientation fracture blasting with LSC is a good means in directional fracture controlled blasting and is worth popularizing widely. 展开更多
关键词 linear shaped charge(LSC) standoff sand-cement grout sample directional fracture controlled blasting
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Impact of Eccentricity on Nonlinear Oscillations of a Point-Like Charge in the Electric Field of a Curvature-Dependent Elliptic Charged Ellipse 被引量:1
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作者 Haiduke Sarafian 《American Journal of Computational Mathematics》 2020年第4期603-611,共9页
Calculation of the interactive force between two horizontally stacked circular uniformly charged rings placed along the common vertical axis conducive to nonlinear oscillations under gravity has been addressed [1]. Al... Calculation of the interactive force between two horizontally stacked circular uniformly charged rings placed along the common vertical axis conducive to nonlinear oscillations under gravity has been addressed [1]. Although challenging, nonetheless the scope of the study limited to uniform charge distributions of the rings. Here we extend the analysis considering a charged ellipse with a nonuniform, curvature-dependent elliptic charge distribution exerting a force on a point-like charge placed on the vertical symmetry axis. Nonuniform charge distribution and its impact on various practical scenarios are not a common theme addressed in literature. Applying Computer Algebra System (CAS) particularly <em>Mathematica</em> [2], we analyze the issue on hand augmenting the traditional scope of interest. We overcome the CPU expensive symbolic computation following our newly developed numeric/symbolic method [1]. For comprehensive understanding, we simulate the nonlinear oscillations. 展开更多
关键词 Nonlinear Oscillations Elliptic Curvature-Dependent charge Distribution Computer Algebra System Mathematica
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THE E2 EFFECTIVE CHARGE IN LOW-ENERGY NEUTRON RADIATIVE CAPTURE
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作者 HO Yukun 《Chinese Physics Letters》 SCIE CAS 1986年第8期369-372,共4页
It is shown that the concept of effective charge can be used to explain low-energy neutron E2 radiative capture.The quantitative analyses of the ^(13)C(n,γ)at 0.1529MeV resonance and ^(20)Ne(n,γ),^(25)Mg(n,γ)at the... It is shown that the concept of effective charge can be used to explain low-energy neutron E2 radiative capture.The quantitative analyses of the ^(13)C(n,γ)at 0.1529MeV resonance and ^(20)Ne(n,γ),^(25)Mg(n,γ)at thermal energy illustrate that an effective charge equal to 0.5e is required to explain the measured data.This value is consistent with that used for bound state to bound state E2 transition in the same mass region. 展开更多
关键词 EXPLAin charge RADIATIVE
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INVESTIGATION OF CHARGE INTENSIFICATION EFFECT IN a-Si:H BY MEANS OF PHOTOELECTRIC SENSITIVITY METHOD
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作者 Hai Yuhan Hai Hao Xi Zhonghe Zhang Qiang(institute of Electronics, Academia Sinica, Beijing 100080)(Nankai University, Tianjin 300071)(Beijing University, Beijing 100871) (Beijing United University, Beijing 100101) 《Journal of Electronics(China)》 1999年第1期81-87,共7页
The photocurrent-voltage characteristics and photoelectric sensitivity of a-Si:H samples with slit and comb electrodes are measured. A method for calculating the charge intensifying gain from the photoelectric sensiti... The photocurrent-voltage characteristics and photoelectric sensitivity of a-Si:H samples with slit and comb electrodes are measured. A method for calculating the charge intensifying gain from the photoelectric sensitivity is proposed. The obtained charge intensifying gain of a-Si:H under an electric field of 105 V/cm through this method is as high as 4.3×103. The generation process of the charge intensification effect in a-Si:H is discussed on the basis of the energy level diagram. And the product of electron’s mobility and its lifetime is calculated from the measured values of the gains. 展开更多
关键词 A-SI:H semiconductor charge inTENSIFICATION EFFECT PHOTOELECTRIC sensitivity METHOD
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Measurement and analyses of the mean effective ion charge in the centre of tokamak discharges
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作者 郑永真 丁玄同 周艳 《Chinese Physics B》 SCIE EI CAS CSCD 2007年第4期1084-1088,共5页
There are two different definitions for specifying the mean effective ion charge Zeff in plasmas: a) from the Spizer electrical resistivity of the plasma and b) from bremsstrahlung radiation losses of the plasma. I... There are two different definitions for specifying the mean effective ion charge Zeff in plasmas: a) from the Spizer electrical resistivity of the plasma and b) from bremsstrahlung radiation losses of the plasma. In this paper Zeff in the centre of tokamak ohmic discharges has been determined from information on sawtooth-relaxations of the steady state plasma, based on the analysis for the power balance of the plasma electrons in the plasma centre during the period of recovery after the sawtooth crashes. This method is found to supply reliable results for tokamak parameters. While its application requires some efforts in data analysis, it can provide a reliable determination of Zeff, independent of the information from bremsstrahlung radiation losses of the plasma. 展开更多
关键词 mean effective ion charge sawtooth relaxation oower balance of plasma electrons
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Thermal properties of regular black hole with electric charge in Einstein gravity coupled to nonlinear electrodynamics
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作者 Yi-Huan Wei 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第12期113-117,共5页
We propose a regular spherically symmetric spacetime solution with three parameters in Einstein gravity coupled to nonlinear electrodynamics(NED), which describes the NED black hole with electric charge. It is found t... We propose a regular spherically symmetric spacetime solution with three parameters in Einstein gravity coupled to nonlinear electrodynamics(NED), which describes the NED black hole with electric charge. It is found that the system enclosed by the horizon of NED spacetime satisfies the first law of thermodynamics. In order to obtain the NED spacetime with only electric charge, the case of two parameters taking the same value is considered. In this case, we express the mass of the NED spacetime as a function of the entropy and electric charge of the NED black hole, give the Smarr-like formula and the approximate Smarr formula for the mass of NED spacetime. 展开更多
关键词 regular nonlinear electrodynamics(NED) spacetime NED black hole with electric charge first law of thermodynamics Smarr formula
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Kinetic study of key species and reactions of atmospheric pressure pulsed corona discharge in humid air
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作者 Yongkang PENG Xiaoyue CHEN +6 位作者 Yeqiang DENG Lei LAN Haoyu ZHAN Xuekai PEI Jiahao CHEN Yukuan YUAN Xishan WEN 《Plasma Science and Technology》 SCIE EI CAS CSCD 2022年第5期154-168,共15页
In this study, we examined the key particles and chemical reactions that substantially influence plasma characteristics. In summarizing the chemical reaction model for the discharge process of N_(2)–O_(2)–H_(2)O(g)m... In this study, we examined the key particles and chemical reactions that substantially influence plasma characteristics. In summarizing the chemical reaction model for the discharge process of N_(2)–O_(2)–H_(2)O(g)mixed gases, 65 particle types and 673 chemical reactions were investigated. On this basis, a global model of atmospheric pressure humid air discharge plasma was developed, with a focus on the variation of charged particles densities and chemical reaction rates with time under the excitation of a 0–200 Td pulsed electric field. Particles with a density greater than 1% of the electron density were classified as key particles. For such particles, the top ranking generation or consumption reactions(i.e. where the sum of their rates was greater than 95% of the total rate of the generation or consumption reactions) were classified as key chemical reactions. On the basis of the key particles and reactions identified, a simplified global model was derived. A comparison of the global model with the simplified global model in terms of the model parameters, particle densities, reaction rates(with time), and calculation efficiencies demonstrated that both models can adequately identify the key particles and chemical reactions reflecting the chemical process of atmospheric pressure discharge plasma in humid air. Thus, by analyzing the key particles and chemical reaction pathways, the charge and substance transfer mechanism of atmospheric pressure pulse discharge plasma in humid air was revealed, and the mechanism underlying water vapor molecules’ influence on atmospheric pressure air discharge was elucidated. 展开更多
关键词 atmospheric humid air key charged particles key chemical reactions reaction pathways
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Discovery &Proofs of a Nucleus of Mass and Charge in the Photons/Quantum Particles
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作者 Narendra Swarup Agarwal 《Journal of Modern Physics》 2018年第12期2170-2192,共23页
This work discovers and proves that all the photons/quantum particles have a “Nucleus of mass and charge.” The nucleus is located off-center in the particles. The constructive, destructive and intermediate Interfere... This work discovers and proves that all the photons/quantum particles have a “Nucleus of mass and charge.” The nucleus is located off-center in the particles. The constructive, destructive and intermediate Interference phenomena decisively discover and prove the presence of only one nucleus of the mass located off-center in a photon, like an atomic nucleus. The mass in the nucleus of a photon develops varying forces to move the photon as a wave. The Wave-Particle Duality is the most significant proof of such a nucleus of mass. The formation of an electromagnetic wave by a photon proves the presence of a charge in the nucleus of the photon. The Quantum Theory, developed about 100 years back, simplified the understanding of matter and energy at the atomic/subatomic levels. However, the Quantum Theory remains incomplete and cannot explain even a single quantum phenomenon. The New Quantum Theory, developed in the year 2012, is based on the similarity of an atomic nucleus as well as the solar system with the Sun as its nucleus of the mass and the charge. The New Quantum Theory explains all the Quantum Phenomena and matches with the Classical Mechanics as well as the Theory of Electromagnetism. The experiments described in this work, using high precision instruments, determine the mass, the charge and the diameter of a photon/quantum particle. 展开更多
关键词 NUCLEUS Off-Center Location MASS Acceleration Force and charge
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Simulation of Space Charge Impact on Partial Discharge Inception Voltage in Power Busbars Dedicated to Future Hybrid Aircrafts
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作者 Mallys Elliazar Banda David Malec Jean-Pascal Cambronne 《Circuits and Systems》 2018年第11期196-212,共17页
Reducing greenhouse gases, saving energy resources and mass optimization require technological changes towards increasingly electric vehicles. At the same time, performance improvement of semiconductor and dielectric ... Reducing greenhouse gases, saving energy resources and mass optimization require technological changes towards increasingly electric vehicles. At the same time, performance improvement of semiconductor and dielectric materials further promotes electronic components confinement, resulting in a significant increase of embedded power densities. In the particular case of future hybrid propulsion aircrafts, electrical power that intended to supply reactors would be converted through power electronics components mounted on power busbars and insulated by solid dielectrics materials. These dielectrics materials have to respond to various electrical constraints of use (HVDC), in spite of environment change of aircraft parameters such as low pressure, temperature and thermal cycles, humidity... Unfortunately, partial discharges phenomenon is the most problem within electrical insulation system (EIS). Based on a topological model of power busbars designed for power converters dedicated to hybrid aircraft, partial discharge studies were conducted by simulation in various charging conditions of a PTFE insulator. Simulation results, which focus on electric field thresholds criteria of partial discharge inception voltage in air, reveal a net sensitivity of a space charge accumulation and distribution on dielectrics behaviour even for low space charge density, depending on their location in dielectrics. Compared to the behaviour observed with implanted homocharges, when by increasing homocharges density from 0.5 C/m3 to 2 C/m3 we observe a decrease of electric field by 450%, simulation results show a highest risk of partial discharge inception when heterocharges are accumulated inside dielectrics. Their accumulation increases the electric field in triple points beyond electric field thresholds of partial discharge inception in air. The simulated electric field reaching 22 kV/mm with only 2 C/m3 of heterocharges density accumulated in dielectric/busbars interfaces. 展开更多
关键词 SIMULATION Partial DIScharge Space charge POWER BUSBARS HYBRID Aircraft
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