Summary form only given. Atmospheric-pressure room-temperature plasma jets are commonly used in plasma medicine, nanotechnology, as well as surface and materials processing. Most of the applications require room-tempe...
详细信息
Summary form only given. Atmospheric-pressure room-temperature plasma jets are commonly used in plasma medicine, nanotechnology, as well as surface and materials processing. Most of the applications require room-temperature operation while completely avoiding the glow-to-arc transitions. To meet these requirements, the atmospheric plasma jets are usually sustained in noble gases. However, this is very challenging for the open-air operation. Moreover, the cross-sections of the plasma plumes are typically very small, which make large-area surface processing particularly difficult. One promising way to overcome this shortcoming is by using the plasma jet arrays. However, since the individual plasma plumes generated by the arrayed plasma jets are in most cases independent and do not merge in open air, it is very difficult to achieve uniform plasmas and surface treatment effects. In this paper, we demonstrate a homogenous cold air plasma glow with a large cross-section generated by a direct current power supply. There is no risk of glow-to-arc transitions, and the plasma glow appears uniform regardless of the gap between the nozzle and the surface being processed. Detailed studies show that both the position of the quartz tube and the gas flow rate affect the plasma characteristics. Further investigation indicates that the residual charges trapped on the inner surface of the quartz tube may be responsible for the generation of the air plasma plume with a large cross-section. Moreover, the spatially resolved optical emission spectroscopy reveals that the air plasma plume is uniform as it propagates out of the nozzle. The air plasma plume with remarkable improvement of the plasma uniformity is used to improve the bio-compatibility of a glass coverslip over a reasonably large area. This improvement is demonstrated by a much more uniform and effective attachment and proliferation of human embryonic kidney 293 (HEK 293) cells on the plasma-treated surface.
The interior permanent magnet (IPM) machine with fractional-slot concentrated-windings (FSCW) has become a popular research topic owing to their novel structures and attracting potentials. This paper is focused on ind...
详细信息
The interior permanent magnet (IPM) machine with fractional-slot concentrated-windings (FSCW) has become a popular research topic owing to their novel structures and attracting potentials. This paper is focused on inductances and saliency ratios in IPM FSCW machines with different pole and slot combinations. Analytical expressions of inductances and saliency ratios are derived using harmonic analysis method (HAM) and their features and trends are concluded. The concept of dq-axis equivalent windings containing harmonic components is proposed to help better understand these features and trends. It explains the phenomenon that configurations with fewer stator slots and fewer winding layers have lower saliency ratio. Theoretical conclusions are verified by finite-element (FE) method.
We proposed a novel visible polarizer based on multilayer silicon and silicon oxide alternative subwavelength grating and its optical characteristic is numerically investigated by finite difference time domain method....
详细信息
We proposed a novel visible polarizer based on multilayer silicon and silicon oxide alternative subwavelength grating and its optical characteristic is numerically investigated by finite difference time domain method. The reflectance of TE mode and transmission of TM mode are above 90% with extinction ratio up to 10 3 . Moreover, the proposed polarizer also has wide angular field and large fabrication tolerance.
A fast π bistable twist nematic (π-BTN) liquid crystal display controlled by nucleation process is developed. The nucleation induced by the patterned spacer inside the cell. The response time is fast and it depends ...
A fast π bistable twist nematic (π-BTN) liquid crystal display controlled by nucleation process is developed. The nucleation induced by the patterned spacer inside the cell. The response time is fast and it depends on the density of patterned spacer.
In order to assess transformer's status and forecast its potential fault, this paper applied Bayesian network classifier into transformer fault diagnosis, combined with dissolved gas analysis and other electrical ...
详细信息
In order to assess transformer's status and forecast its potential fault, this paper applied Bayesian network classifier into transformer fault diagnosis, combined with dissolved gas analysis and other electrical test results, and thereby created a transformer fault synthetic diagnosis method. Build up transformer's fault diagnosis model based on Naive Bayesian Classifier and Tree Augmented Naive Bayesian Classifier respectively, and verify their validity by instance.
Deconvolution has become one of the most used methods for improving spectral resolution, and blind deconvolution as a typical method has been researched widely. However, the predefined point spread function (PSF) used...
详细信息
ISBN:
(纸本)9781479927654
Deconvolution has become one of the most used methods for improving spectral resolution, and blind deconvolution as a typical method has been researched widely. However, the predefined point spread function (PSF) used in blind deconvolution method is not known exactly in practice. In general, the PSF is estimated simultaneously from the observed spectrum, but it becomes difficult when the spectroscopic data are polluted by strong noise. In this paper, we present a deconvolution method used to improve the resolution of THz spectrum. In the method, the energy function is constructed, which includes the likelihood term, Total variation of spectrum term and L2 norm of the PSF term. The PSF is modeled as a parametric function combination with the a priori knowledge about the characteristics of the instrumental response. The spectrum and the parameter of PSF are obtained by minimizing the energy functional using alternate minimization approach. Experimental results are shown to demonstrate the efficiency of the proposed method used for THz spectrum.
To compare with resonant magnetic perturbations(RMPs) related experimental results observed in J-TEXT tokamak,nonlinear numerical modeling based on reduced MHD equations has been carried *** experimental parameters as...
详细信息
To compare with resonant magnetic perturbations(RMPs) related experimental results observed in J-TEXT tokamak,nonlinear numerical modeling based on reduced MHD equations has been carried *** experimental parameters as input,both the mode locking and mode stabilization by RMPs are also obtained from numerical modeling. Further calculations have been carried out to study the plasma parameters affecting the mode stabilization by RMPs,including the plasma rotation frequency,viscosity,Alfven velocity and the RMP *** is found that the suppression of the tearing mode by RMPs of moderate amplitude is possible for a sufficiently high ratio of plasma rotation velocity to the Alfven speed.A larger plasma viscosity enhances the mode stabilization. In addition,the non-uniform mode rotation frequency,modulated by electromagnetic force(Fern) and viscous force(Fvs),results in the applied RMPs contributing both net stabilizing and braking effect on *** evaluation based on analytical theory shows the applied RMP contributes a dominant stabilizing effect,which are responsible for the suppression of *** dynamics of the first discovered small locked island(SLI) are *** is found that the island is locked at the stabilizing phase and the saturated island width is less than the linear layer *** simulated Mirnov signal indicates the small locked island is likely to be the complete suppression case observed in experiments. The comparisons between the numerical and experimental results are in good agreement.
With the rapid growth of power system, it is becoming increasingly difficult to realize reach and time coordination for conventional backup protection. To cope with those problems, wide-area protection is widely resea...
详细信息
Vernier permanent magnet (VPM) machines are well known for high torque density but low power factor. This paper deals with the low power factor of VPM machines. The goal is not obtained by reducing the electrical load...
详细信息
ISBN:
(纸本)9781479903375
Vernier permanent magnet (VPM) machines are well known for high torque density but low power factor. This paper deals with the low power factor of VPM machines. The goal is not obtained by reducing the electrical loading or adjusting current advance angle but proposing a novel vernier topology- dual-stator, spoke-array (DSSA) VPM topology. In this paper, the characteristics, such as active part, auxiliary mechanical structure and rotor anisotropy, of the DSSA VPM topology are analyzed in detail. Performances, including power factor, torque density, and cogging torque etc., are evaluated based on finite element analysis (FEA). The analysis results show that the DSSA VPM topology exhibits high power factor viz.,~0.9 and significantly high torque capability. Finally, the prototype machine has been designed, built, and is under testing. The verification of the mechanical structure scheme is done in this paper, and the experimental results will be presented in the near future.
Surface tension driven self-assembly has been demonstrated to be a promising method for mass production of highly 3-D MEMS structures. However, factors and their mechanisms affecting the self-assembly precision of the...
详细信息
暂无评论