Diagnosis of Electronic Excitation Temperature in Surface Dielectric Barrier Discharge Plasmas at Atmospheric Pressure

The electronic excitation temperature of a surface dielectric barrier discharge （DBD） at atmospheric pressure has been experimentally investigated by optical emission spectroscopic measurements combined with numerical simulation. Experiments have been carried out to deter- mine the spatial distribution of electric field by using FEM software and the electronic excitation temperature in discharge by calculating ratio of two relative intensities of atomic spectral lines. In this work, we choose seven Ar atomic emission lines at 415.86 nm [（3s^23p^5）5p →（3s^23p^5）4s] and 706.7 nm, 714.7 nm, 738.4 nm, 751.5 nm, 794.8 nm and 800.6 nm [（3s^23p^5）4p → （3s^23p^5）4s] to estimate the excitation temperature under a Boltzmann approximation. The average electron energy is evaluated in each discharge by using line ratio of 337.1 nm （N2（C^3Пu →B3Пg）） to 391.4 nm （N2^＋（B2 ∑u^＋→ ∑g^＋））. Furthermore, variations of the electronic excitation tempera- ture are presented versus dielectric thickness and dielectric materials. The discharge is stable and uniform along the axial direction, and the electronic excitation temperature at the edge of the copper electrode is the largest. The corresponding average electron energy is in the range of 1.6- 5.1 eV and the electric field is in 1.7-3.2 MV/m, when the distance from copper electrode varies from 0 cm to 6 cm. Moreover, the electronic excitation temperature with a higher permittivity leads to a higher dissipated electrical power.

Multiple current peaks and spatial characteristics of atmospheric helium dielectric barrier discharges with repetitive unipolar narrow pulse excitation

Atmospheric dielectric barrier discharges driven by repetitive unipolar narrow pulse excitation are investigated numerically by using one-dimensional fluid models.The one-dimensional simulation focuses on the effects of applied voltage amplitude,pulse repetition frequency,gap width andγcoefficient on the multiple-current-pulse(MCP)discharge.The results indicate that the MCP behavior will lead to the stratification of electron density distribution in axial direction.Traditional MCP manipulating methods,such as reducing the applied voltage amplitude,increasing the applied voltage frequency,adjusting the gap width,cannot regulate MCPs exhibiting in this work.Further analyses reveal that the increasing electric field of the cathode fall region is the basis for the emergence of MCP behavior.

Performance improvement of magneto-acousto-electrical tomography for biological tissues with sinusoid-Barker coded excitation

By combining magnetics, acoustics and electrics, the magneto-acoustic-electrical tomography（MAET） proves to possess the capability of differentiating electrical impedance variation and thus improving the spatial resolution. However,the signal-to-noise ratio（SNR） of the collected MAET signal is still unsatisfactory for biological tissues with low-level electrical conductivity. In this study, the formula of MAET measurement with sinusoid-Barker coded excitation is derived and simplified for a planar piston transducer. Numerical simulations are conducted for a four-layered gel phantom with the 13-bit sinusoid-Barker coded excitation, and the performances of wave packet recovery with side-lobe suppression are improved by using the mismatched compression filter, which is also demonstrated by experimentally measuring a three-layered gel phantom. It is demonstrated that comparing with the single-cycle sinusoidal excitation, the amplitude of the driving signal can be reduced greatly with an SNR enhancement of 10 dB using the 13-bit sinusoid-Barker coded excitation. The amplitude and polarity of the wave packet filtered from the collected MAET signal can be used to achieve the conductivity derivative at the tissue boundary. In this study, we apply the sinusoid-Barker coded modulation method and the mismatched suppression scheme to MAET measurement to ensure the safety for biological tissues with improved SNR and spatial resolution, and suggest the potential applications in biomedical imaging.

Development of High Torque and High Power Density Hybrid Excitation Flux Switching Motor for Traction Drive in Hybrid Electric Vehicles

This paper presents design feasibility study and development of a new hybrid excitation flux switching motor (HEFSM) as a contender for traction drives in hybrid electric vehicles (HEVs). Initially, the motor general construction, the basic working principle and the design concept of the proposed HEFSM are outlined. Then, the initial drive performances of the proposed HEFSM are evaluated based on 2D-FEA, in which the design restrictions, specifications and target performances are similar with conventional interior permanent magnet synchronous motor (IPMSM) used in HEV. Since the initial results fail to achieve the target performances, deterministic design optimization approach is used to treat several design parameters. After several cycles of optimization, the proposed motor makes it possible to obtain the target torque and power of 333 Nm and 123 kW, respectively. In addition, due to definite advantage of robust rotor structure of HEFSM, rotor mechanical stress prediction at maximum speed of 12,400 r/min is much lower than the mechanical stress in conventional IPMSM. Finally, the maximum torque and power density of the final design HEFSM are approximately 11.41 Nm/kg and 5.55 kW/kg, respectively, which is 19.98% and 58.12% more than the torque and power density in existing IPMSM for Lexus RX400h.

IMPROVEMENT OF EXPRESSION FOR EXCITATION BY AN ELECTRIC DIPOLE IN GTEM CELL

On the basis of Wilson's work in which the vertical electric dipole is centrally located in GHz Transverse ElectroMagnetic (GTEM) cell, we deduce the expression for the field distribution excited by an electric dipole in the case that the dipole is not centrally located. It will be useful for EMC measurements using GTEM cell.

Si_2O_2 molecule:structure of ground state and the excited properties under different external electric fields

Geometry and vibrational frequencies of the ground state of Si2O2 molecule are studied using density function theory （DFT） at the level of cc-pvtz and 6-311-k＋G^＊＊. It is found that the optimizing value by B31yp/cc-pvtz is closer to the experimental data. The excited properties under different external electric fields are also investigated by the time-dependent-DFT method. Transitions from the ground state of Si2O2 molecule to the first singlet state under different external electric fields can take place more easily. The corresponding absorption spectral line is about 360 nm in wavelength and the excitation energy is about 3.4 eV.

Hybrid Excited Permanent Magnet Machines for Electric and Hybrid Electric Vehicles

This paper reviews various hybrid excited(HE)machines from the perspective of location of PM and DC excitation,series/parallel connection of PM and DC excited magnetic fields,and 2D/3D magnetic fields,respectively.The advantages as well as drawbacks of each category are analyzed.Since an additional control degree,i.e.DC excitation,is introduced in the HE machine,the flux weakening control strategies are more complex.The flux weakening performance as well as efficiency are compared with different control strategies.Then,the potential to mitigate the risk of uncontrolled overvoltage fault at high speed operation is highlighted by controlling the field excitation.Since additional DC coils are usually required for HE machines compared with pure PM excitation,the spatial confliction inevitably results in electromagnetic performance reduction.Finally,the technique to integrate the field and armature windings with open-winding drive circuit is introduced,and novel HE machines without a DC coil are summarized.

Quantitative evaluation of extrinsic factors influencing electrical excitability in neuronal networks： Voltage Threshold Measurement Method(VTMM)

The electrical excitability of neural networks is influenced by different environmental factors. Effective and simple methods are required to objectively and quantitatively evaluate the influence of such factors, including variations in temperature and pharmaceutical dosage. The aim of this paper was to introduce ‘the voltage threshold measurement method＇, which is a new method using microelectrode arrays that can quantitatively evaluate the influence of different factors on the electrical excitability of neural networks. We sought to verify the feasibility and efficacy of the method by studying the effects of acetylcholine, ethanol, and temperature on hippocampal neuronal networks and hippocampal brain slices. First, we determined the voltage of the stimulation pulse signal that elicited action potentials in the two types of neural networks under normal conditions. Second, we obtained the voltage thresholds for the two types of neural networks under different concentrations of acetylcholine, ethanol, and different temperatures. Finally, we obtained the relationship between voltage threshold and the three influential factors. Our results indicated that the normal voltage thresholds of the hippocampal neuronal network and hippocampal slice preparation were 56 and 31 m V, respectively. The voltage thresholds of the two types of neural networks were inversely proportional to acetylcholine concentration, and had an exponential dependency on ethanol concentration. The curves of the voltage threshold and the temperature of the medium for the two types of neural networks were U-shaped. The hippocampal neuronal network and hippocampal slice preparations lost their excitability when the temperature of the medium decreased below 34 and 33°C or increased above 42 and 43°C, respectively. These results demonstrate that the voltage threshold measurement method is effective and simple for examining the performance/excitability of neuronal networks.

Design and Comparison of Electrically Excited Double Rotor Flux Switching Motor Drive Systems for Automotive Applications

This paper presents a cost-effective driving system for automotive applications based on a double rotor electrically excited flux switching machine(FSM).Benefiting from a double rotor topology,this FSM can realize a drum winding design and thus winding ends are effectively shorten and the copper loss is mitigated.The machine structure,operation principle and design consideration are studied and further verified by time-stepping finite element method.Moreover,three topologies of drive circuit for the proposed FSM are introduced.By using electromagnetic-circuit coupling simulation,a comparison between three different three drive systems are performed,with focus on the system cost and overall electromagnetic performance,especially the effect of current control and torque ripple.A prototype is established and tested.Relevant experimental results verify the effectiveness of the proposed new FSM drive system.

Three-dimensional forward modeling and inversion of borehole-to-surface electrical imaging with different power sources

Borehole-to-surface electrical imaging （BSEI） uses a line source and a point source to generate a stable electric field in the ground. In order to study the surface potential of anomalies, three-dimensional forward modeling of point and line sources was conducted by using the finite-difference method and the incomplete Cholesky conjugate gradient （ICCG） method. Then, the damping least square method was used in the 3D inversion of the formation resistivity data. Several geological models were considered in the forward modeling and inversion. The forward modeling results suggest that the potentials generated by the two sources have different surface signatures. The inversion data suggest that the low- resistivity anomaly is outlined better than the high-resistivity anomaly. Moreover, when the point source is under the anomaly, the resistivity anomaly boundaries are better outlined than when using a line source.

Properties of a Si_2N molecule under an external electric field

In the present work,we adopt the ccsd/6-31g（d） method to optimize the ground state structure and calculate the vibrational frequency of the Si2N molecule.The calculated frequencies accord satisfactorily with the experimental values,which helps confirm the ground state structure of the molecule.In order to find how the external electric field affects the Si2N molecule,we use the density functional method B3P86/6-31g（d） to optimize the ground state structure and the time-dependent density functional theory TDDFT/6-31g（d） to study the absorption spectra,the excitation energies,the oscillator strengths,and the dipole moments of the Si2N molecule under different external electric fields.It is found that the absorption spectra,the excitation energies,the oscillator strengths,and the dipole moments of the Si2N molecule are affected by the external electric field.One of the valuable results is that the absorption spectra of the yellow and the blue-violet light of the Si2N molecule each have a red shift under the electric field.The luminescence mechanism in the visible light region of the Si2N molecule is also investigated and compared with the experimental data.

Electronic Structure and Physical Characteristics of Dioxin Under External Electric Field

Dioxin is a highly toxic and caustic substance,which widely existed in the atmosphere,soil and water with tiny particles.Dioxin pollution has become a major problem that concerns the survival of mankind,which must be strictly controlled.The bond length,bond angle,energy,dipole moment,orbital energy level distribution of dioxin under the external field are investigated using DFT(density functional theory)on basis set level of B3LYP/6-31G(d,p).The results indicate that with the increase of the electric field,the length of one Carbon-Oxygen bond increases while another Carbon-Oxygen bond decreases.The energy gradually decreases with the electric field,while the change of the dipole moment has an opposite trend.In the infrared spectra,the vibration frequency decreases with the electric field increasing and shows an obvious red shift.Moreover,the ultraviolet-visible absorption spectra under different electric fields are analyzed with TD-DFT(time-dependent density functional theory)method.The wavelength of the strongest absorption peak increases and occurs red shift with the increase of the electric field.All the above results can provide reference for further research on the properties of dioxin under different external electric field.

Photoluminescence of green nanophosphors Sr_(2)MgSi_(2)O_(7)doped with Tb^(3+)under 374-nm excitation

A series of Sr_(2)MgSi_(2)O_(7):Tb^(3+)nanophosphors is prepared using a high-temperature solid-state reaction.The x-ray diffraction patterns show that the crystal structure of the sample is not significantly affected by Tb^(3+)ions.However,the images of the scanning electron microscope illustrate that the average size of nanoparticles becomes larger with the increase of Tb^(3+)concentration.Unlike earlier investigations on down-conversion emission of Tb^(3+)ion excited by deep ultraviolet light,in this work,the photoluminescence characteristics of Sr_(2)MgSi_(2)O_(7)nanophosphors doped with different Tb^(3+)concentrations are analyzed under 374-nm excitations.The intense green emission at 545 nm is observed at an optimal doping concentration of 1.6 mol%.The main reason for the concentration quenching is due to the electric dipole-electric dipole interaction among Tb^(3+)ions.

Hybrid Excitation Flux Switching Motor with Permanent Magnet Placed at Middle of Field Coil Slots and High Filling Factor Windings

Design and experimental studies on a hybrid excitation flux switching motor as a traction motor for hybrid electric vehicles drive are presented.A stator body of the motor consists of not only laminated silicon-iron electromagnetic steel and three-phase armature windings,but also both of field excitation coils and permanent magnets working together as a variable field magnetomotive force source.On the other hand,a rotor is composed of just laminated silicon-iron electromagnetic steel with salient poles like switched reluctance motor.To bring out the best in drive performances of the hybrid excitation flux switching motor as a variable flux motor for the application,each material adopted for the stator and rotor body should be designed properly in terms of motor efficiency,maximum torque and power densities and so forth.As some of them,in this paper,thinner silicon-iron electromagnetic steel sheet and permanent magnets with high remanent and low amount of Dysprosium used are applied for achieving higher motor efficiency.Moreover,all coils wound flatwise and edgewise using rectangular wires are introduced to realizing high filling factor for reduced copper losses.Experimental tests using a 60kW prototype of the motor demonstrates the designed motor has good motor efficiency under frequent operating points expected for the target vehicle drive.

Self-screening of the polarized electric field in wurtzite gallium nitride along[0001]direction

The strong polarization effect of GaN-based materials is widely used in high-performance devices such as white-lightemitting diodes(white LEDs),high electron mobility transistors(HEMTs),and GaN polarization superjunctions.However,the current researches on the polarization mechanism of GaN-based materials are not sufficient.In this paper,we studied the influence of polarization on electric field and energy band characteristics of Ga-face GaN bulk materials by using a combination of theoretical analysis and semiconductor technology computer-aided design(TCAD) simulation.The selfscreening effect in Ga-face bulk GaN under ideal and non-ideal conditions is studied respectively.We believe that the formation of high-density two-dimensional electron gas(2 DEG) in GaN is the accumulation of screening charges.We also clarify the source and accumulation of the screening charges caused by the GaN self-screening effect in this paper and aim to guide the design and optimization of high-performance GaN-based devices.

Ab initio study offree radical underthe Si （CH3） 2O doubleexternal electric field

Infrared spectrum and NMR chemical shifts of Si (CH3)2O double free radical were calculatedemploying density functional theory(DFT) with the basis sets 6 - 311 + G(2d, p). Excited states, dipole momentand energy of Si(CH3 )2O double free radical were also calculated using time dependent density function theory(TD-DFT) with the same basis sets. It is found that the external electric field along the X,Y and Z axis affectdifferently on the excited states and other properties of Si(CH3)2O double free radical.

Analysis of Small Oscillations in Complex Electric Power Systems

In this article the mathematical model of complex regulated electric system in matrix form is developed. This mathematical model makes it possible to study the steady-state stability of a complex electrical system by determining the eigenvalues of the dynamics matrix. The model of an electrical system that reflects transient processes for small deviations is convenient, both algorithmically and computationally, in particular, in cases of their joint solution with steady-state equations—the equations of nodal voltages. The obtained results in the form of the eigenvalues of the matrix spectrum are qualitatively the same as the results of classical studies, which is a consequence of the adequacy of the proposed model and the correct reflection of the dynamic processes occurring in a real electrical system. In addition, the equations obtained are of independent importance for the analysis of various modes, including transient, electrical systems of any complexity.

Photo-Doped Active Electrically Controlled Terahertz Modulator

We demonstrate an electric-controlled terahertz（THz） modulator which can be used to realize amplitude modulation of terahertz waves with slight photo-doping. The THz pulse transmission was efficiently modulated by electrically controlling the monolayer silicon-based device. The modulation depth reached 100% almost when the applied voltage was 7V at an external laser intensity of 0.6W/cm2. The saturation voltage reduced with the increase of the photo-excited intensity. In a THz continuous wave（CW）system, a significant fall in both THz transmission and reflection was also observed with the increase of applied voltage. This reduction in the THz transmission and reflection was induced by the absorption for electron injection. The results show that a high-efficiency and high modulation depth broadband electric-controlled terahertz modulator in a pure Si structure has been realized.

The Nature, Origin and Propagation of the Electric Field: A New Insight to Fundamental Physics

The nature, origin and propagation of the electric field are discussed for the first time on the basis of the presence of vibrating strings in the space and their self-excitation process. It is considered that the electron is formed from strings and it has specific vibrational frequency. This excites the strings which are close by with the self-excitation process. This procedure which is continuous in the space according to the symmetry and vibrational energy in the form of waves spreads near the electron (or the charge particle), which behaves and carries energy known as electric field. In fact, the electron does not continuously emit energy in any form but induces (or excites) and organizes energy in a self-sustain vibrational form and extends in three dimensional space. Only on the basis of the presence of strings (vibrational energy), several electromagnetic phenomena have been explained in a consistent way. The vibrational nature of the electric field is also examined with the help of Stark effect and X-ray diffraction approach to support the present view.

Therapeutic Basis of Electromagnetic Resonances and Signal-Modulation

The medical application of electromagnetic resonances is a controversial area of knowledge. Numerous unproven statements and some medical quackeries were published and distributed in informal channels among suffering patients. The fake information is hazardous in such severe diseases as cancer. The optimal, high efficacy energy transport by resonances attracts the interest of the experts and the public. The focus of the attention is technical and concentrates on the careful selection and excitation of the target compounds or cells, expecting helpful modifications. The complication is the complexity of the living systems. The targets are interconnected with an extensive network in the tissues where homeostasis, a dynamic equilibrium, regulates and controls changes. The broad range of energy-transfer variants could cause resonant effects, but the necessary criteria for the selection and proper action have numerous limits. The modulated high-frequency carrier may solve a part of the problem. This mixed solution uses the carrier and modulation’s particular properties to solve some of the obstacles of selection and excitation processes. One of the advantages of modulation is its adaptive ability to the living complexity. The modulated signal uses the homeostatic time-fractal pattern (1/f noise). The task involves finding and providing the best available mode to support the healthy state of the body. The body’s reaction to the therapy remains natural;the modulation boosts the body’s ability for the homeostatic regulation to reestablish the healthy state.