WT8.BZ]A new quasi 2-dimensional analytical approach to predicting the ring voltage,edge peak fields and optimal spacing of the planar junction with a single floating field limiting ring structure has been proposed,ba...WT8.BZ]A new quasi 2-dimensional analytical approach to predicting the ring voltage,edge peak fields and optimal spacing of the planar junction with a single floating field limiting ring structure has been proposed,based on the cylindrical symmetric solution and the critical field concept.The effects of the spacing and reverse voltage on the ring junction voltage and edge peak field profiles have been analyzed.The optimal spacing and the maximum breakdown voltage of the structure have also been obtained.The analytical results are in excellent agreement with that obtained from the 2-D device simulator,MEDICI and the reported result,which proves the presented model valid.展开更多
Avalanche photon diode and avalanche diode array, working in Geiger mode, have single photon detection capability. The structure of guard ring is the key factor to avoid the premature edge breakdown of the avalanche d...Avalanche photon diode and avalanche diode array, working in Geiger mode, have single photon detection capability. The structure of guard ring is the key factor to avoid the premature edge breakdown of the avalanche diode and increase the maximum bias voltage. A new structure of the guard ring is proposed in this letter, in which the floating guard ring is put outside the p-well guard ring. Simulation results indicate that the maximum bias voltage of the proposed guard ring is higher than that of the state-of-the-art methods.展开更多
A C-band accelerator structure was used to accelerate electrons at the Shanghai soft X-ray free-electron laser test facility (SXFEL-TF) in Shanghai Institute of Applied Physics (SINAP). The microwave system of this ac...A C-band accelerator structure was used to accelerate electrons at the Shanghai soft X-ray free-electron laser test facility (SXFEL-TF) in Shanghai Institute of Applied Physics (SINAP). The microwave system of this accelerator structure used a 110 MW pulse modulator and a klystron (PV-5050) to provide the power supply. A pulse transformer is a crucial device in a modulator klystron system and plays significant roles in voltage level transformation, matching impedances, and polarity inversion. This study presents the optimization of a high-voltage pulse transformer. The design considerations of reducing flattop ringing and flattop droop, and shortening leading edge are provided. The model simulation, mechanical design, and the relevant experimental results are also presented.展开更多
A novel compact electromagnetic bandgap （EBG） structure constructed by etching two reverse split rings （RSRs） and inserting interleaving edge （IE） on the patch of conventional mushroom-like EBG （CML-EBG） is in...A novel compact electromagnetic bandgap （EBG） structure constructed by etching two reverse split rings （RSRs） and inserting interleaving edge （IE） on the patch of conventional mushroom-like EBG （CML-EBG） is investigated. Simulated dispersion diagrams show that the proposed EBG structure presents a 13.6% size reduction in the center frequency of the bandgap. Two comparisons have been carried out for the analysis of the effect of the RSRs and IE configuration. Then, a sample of this novel EBG is fabricated and tested, further experimental data agree well with the simulated results. Thus, this EBG structure makes a good candidate to decrease mutual coupling in compact microstrip patch array.展开更多
Acupuncture as a vital component of traditional medical systems of the Far East has been used to restore and maintain health for over three millennia. However, the neurobiological correlates of this therapy remain lar...Acupuncture as a vital component of traditional medical systems of the Far East has been used to restore and maintain health for over three millennia. However, the neurobiological correlates of this therapy remain largely unknown. The purpose of this study was therefore to determine the effect of enpishin acupuncture (press tack needles (PTN)) on autonomic function, WBC count, and oxidative stress between subjects that received either verum or placebo PTN treatment. Twenty men (mean(SD) age: 36.7(5.1) years) who provided oral consent were randomized to receive either verum PTN (n = 9) or placebo PTN (n = 11). Bi-Digital O-Ring Test (BDORT) was used to select the acupoints for each participant. Autonomic function and oxidative stress level were analyzed before and after the treatment via heart rate variability (HRV) and free radical analysis system (FRAS4), respectively. Pre- and post-treatment WBC count was also evaluated. Verum PTN group had a statistically significant increase (p = 0.008) in Ln TP, an index of overall autonomic activity. Subjects in this group also had a significantly greater (p = 0.006) variation in Ln TP than the placebo PTN group in response to the treatment. Similarly, Ln HF of subjects receiving verum PTN showed a marked increase (p = 0.0026) after the treatment. Moreover, a significantly greater (p < 0.001) variation in mean Ln HF before and after the treatment was noted in the verum group than the placebo group, reflecting a greater parasympathetic activation in the former. In contrast, sympathetic activity was not significantly influenced by verum PTN based on the lack of observed changes in LF/HF ratio. In addition, both groups failed to demonstrate significant variations in pre- and post-treatment mean Ln LF/HF ratio. Further, no significant intergroup difference was found with regard to mean variation in Ln LF/HF ratio. Verum PTN did not induce significant changes in WBC count and markers of oxidative stress, namely reactive oxygen species (ROM) and biological antioxidant potential (BAP). However, a comparison of variations in pre- and post-treatment mean WBC count showed a significant difference (p = 0.020) between the two treatment modes: verum group showed a slight increase (225 ± 384.5), while placebo group showed a minimal decrease (–190 ± 272.6). Our findings suggest that PTN increases overall autonomic activity, particularly the parasympathetic function.展开更多
针对机器视觉轴承内圈侧面复杂形状尺寸检测精度低的问题,提出根据检测目标建立小面积感兴趣区域(Region of Interest,ROI)的自适应选取方法和基于Zernike矩的ROI亚像素级边缘提取方法,大幅提升了轴承内圈尺寸的检测精度。首先分别拍摄...针对机器视觉轴承内圈侧面复杂形状尺寸检测精度低的问题,提出根据检测目标建立小面积感兴趣区域(Region of Interest,ROI)的自适应选取方法和基于Zernike矩的ROI亚像素级边缘提取方法,大幅提升了轴承内圈尺寸的检测精度。首先分别拍摄轴承内圈左侧与右侧轮廓图像,对图像进行预处理。在此基础上,通过角点检测融合像素扫描的方法实现自适应ROI选取,解决了因轴承内圈移动引起的小面积ROI边缘误判问题;使用Canny算子提取ROI的像素级边缘,再用改进的Zernike矩算法得到亚像素级边缘。最后,分别对ROI中提取的边缘进行最小二乘圆拟合和直线拟合,根据像素当量与视场间隔将图像中各尺寸转换为轴承内圈实际尺寸。实验结果表明:所提方法测量的标准不确定度低于0.005 mm,满足轴承尺寸高精度检测的要求,对于实现轴承检测的自动化有实际意义。展开更多
Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considere...Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution.展开更多
文摘WT8.BZ]A new quasi 2-dimensional analytical approach to predicting the ring voltage,edge peak fields and optimal spacing of the planar junction with a single floating field limiting ring structure has been proposed,based on the cylindrical symmetric solution and the critical field concept.The effects of the spacing and reverse voltage on the ring junction voltage and edge peak field profiles have been analyzed.The optimal spacing and the maximum breakdown voltage of the structure have also been obtained.The analytical results are in excellent agreement with that obtained from the 2-D device simulator,MEDICI and the reported result,which proves the presented model valid.
文摘Avalanche photon diode and avalanche diode array, working in Geiger mode, have single photon detection capability. The structure of guard ring is the key factor to avoid the premature edge breakdown of the avalanche diode and increase the maximum bias voltage. A new structure of the guard ring is proposed in this letter, in which the floating guard ring is put outside the p-well guard ring. Simulation results indicate that the maximum bias voltage of the proposed guard ring is higher than that of the state-of-the-art methods.
基金supported by the National Natural Science Foundation of China(No.11675250)
文摘A C-band accelerator structure was used to accelerate electrons at the Shanghai soft X-ray free-electron laser test facility (SXFEL-TF) in Shanghai Institute of Applied Physics (SINAP). The microwave system of this accelerator structure used a 110 MW pulse modulator and a klystron (PV-5050) to provide the power supply. A pulse transformer is a crucial device in a modulator klystron system and plays significant roles in voltage level transformation, matching impedances, and polarity inversion. This study presents the optimization of a high-voltage pulse transformer. The design considerations of reducing flattop ringing and flattop droop, and shortening leading edge are provided. The model simulation, mechanical design, and the relevant experimental results are also presented.
文摘A novel compact electromagnetic bandgap （EBG） structure constructed by etching two reverse split rings （RSRs） and inserting interleaving edge （IE） on the patch of conventional mushroom-like EBG （CML-EBG） is investigated. Simulated dispersion diagrams show that the proposed EBG structure presents a 13.6% size reduction in the center frequency of the bandgap. Two comparisons have been carried out for the analysis of the effect of the RSRs and IE configuration. Then, a sample of this novel EBG is fabricated and tested, further experimental data agree well with the simulated results. Thus, this EBG structure makes a good candidate to decrease mutual coupling in compact microstrip patch array.
文摘Acupuncture as a vital component of traditional medical systems of the Far East has been used to restore and maintain health for over three millennia. However, the neurobiological correlates of this therapy remain largely unknown. The purpose of this study was therefore to determine the effect of enpishin acupuncture (press tack needles (PTN)) on autonomic function, WBC count, and oxidative stress between subjects that received either verum or placebo PTN treatment. Twenty men (mean(SD) age: 36.7(5.1) years) who provided oral consent were randomized to receive either verum PTN (n = 9) or placebo PTN (n = 11). Bi-Digital O-Ring Test (BDORT) was used to select the acupoints for each participant. Autonomic function and oxidative stress level were analyzed before and after the treatment via heart rate variability (HRV) and free radical analysis system (FRAS4), respectively. Pre- and post-treatment WBC count was also evaluated. Verum PTN group had a statistically significant increase (p = 0.008) in Ln TP, an index of overall autonomic activity. Subjects in this group also had a significantly greater (p = 0.006) variation in Ln TP than the placebo PTN group in response to the treatment. Similarly, Ln HF of subjects receiving verum PTN showed a marked increase (p = 0.0026) after the treatment. Moreover, a significantly greater (p < 0.001) variation in mean Ln HF before and after the treatment was noted in the verum group than the placebo group, reflecting a greater parasympathetic activation in the former. In contrast, sympathetic activity was not significantly influenced by verum PTN based on the lack of observed changes in LF/HF ratio. In addition, both groups failed to demonstrate significant variations in pre- and post-treatment mean Ln LF/HF ratio. Further, no significant intergroup difference was found with regard to mean variation in Ln LF/HF ratio. Verum PTN did not induce significant changes in WBC count and markers of oxidative stress, namely reactive oxygen species (ROM) and biological antioxidant potential (BAP). However, a comparison of variations in pre- and post-treatment mean WBC count showed a significant difference (p = 0.020) between the two treatment modes: verum group showed a slight increase (225 ± 384.5), while placebo group showed a minimal decrease (–190 ± 272.6). Our findings suggest that PTN increases overall autonomic activity, particularly the parasympathetic function.
文摘针对机器视觉轴承内圈侧面复杂形状尺寸检测精度低的问题,提出根据检测目标建立小面积感兴趣区域(Region of Interest,ROI)的自适应选取方法和基于Zernike矩的ROI亚像素级边缘提取方法,大幅提升了轴承内圈尺寸的检测精度。首先分别拍摄轴承内圈左侧与右侧轮廓图像,对图像进行预处理。在此基础上,通过角点检测融合像素扫描的方法实现自适应ROI选取,解决了因轴承内圈移动引起的小面积ROI边缘误判问题;使用Canny算子提取ROI的像素级边缘,再用改进的Zernike矩算法得到亚像素级边缘。最后,分别对ROI中提取的边缘进行最小二乘圆拟合和直线拟合,根据像素当量与视场间隔将图像中各尺寸转换为轴承内圈实际尺寸。实验结果表明:所提方法测量的标准不确定度低于0.005 mm,满足轴承尺寸高精度检测的要求,对于实现轴承检测的自动化有实际意义。
文摘Exact solutions for the flexural vibrations of circular plates having elastic edge conditions along with rigid concentric ring support have been presented in this paper. Values of frequency parameter for the considered circular plate are computed for different sets of values of elastic rotational and translation restraints and the radius of internal rigid ring support. The results for the first three modes of plate vibrations are computed and are presented in tabular form. The effects of rotational and linear restraints and the radius of the rigid ring support on the vibration behavior of circular plates are studied over a wide range of non-dimensional parametric values. The values of the exact frequency parameter presented in this paper for varying values of restraint parameters and the radius of the rigid ring support can better serve in design and as benchmark solutions to validate the numerical methods obtained by using other methods of solution.
