In this paper,in order to stabilize the position and angle of the light source point,a new photon beam position feedback system based on the Photon Beam Position Monitors was developed on Hefei Light Source,and used t...In this paper,in order to stabilize the position and angle of the light source point,a new photon beam position feedback system based on the Photon Beam Position Monitors was developed on Hefei Light Source,and used to correct the position drift and angle variation of the light source at the same time.On introducing the feedback principle,the transfer function matrix is calibrated,indicating that the new system is workable and effective.展开更多
As an important part of the beam diagnostic system, the synchrotron light beam position measurement has a very high value in the high quality and high stability light source applied research. A new photon beam positio...As an important part of the beam diagnostic system, the synchrotron light beam position measurement has a very high value in the high quality and high stability light source applied research. A new photon beam position monitor based on position-sensitive detector (PSD) has been developed to measure the photon beam position in vertical and horizontal directions at the same time at HLS (Hefei Light Source). The new PBPM based on the PSD has fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, and then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. As the results shown, the resolution of the system is better than 3 mm.展开更多
For high-voltage and high-power Gallium Nitride(GaN)power amplifiers,a drain modulation circuit with rapid rise and fall time is proposed in this paper.To decrease the rise and fall time,the high-side bootstrap drive ...For high-voltage and high-power Gallium Nitride(GaN)power amplifiers,a drain modulation circuit with rapid rise and fall time is proposed in this paper.To decrease the rise and fall time,the high-side bootstrap drive circuit with an auxiliary discharge switch is proposed.The effect of the parasitics is analyzed based on calculation and the parallel bonding is proposed.The storage capacitance of power supply is calculated quantitatively to provide large pulse current.To ensure safe operation of the power amplifier,the circuit topology with the dead-time control and sequential control is proposed.Finally,a prototype is built to verify the drain modulation circuit design.The experiments prove that the rise time and fall time of the output pulse signal are both less than 100 ns.展开更多
文章首先采用溶剂热法合成了系列LiMn1-xFexPO4(x=0.15、0.25、0.35、0.45)微纳颗粒,随后采用热分解的方法对微纳颗粒进行碳包覆处理。采用X射线衍射仪(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscope,SEM)对微...文章首先采用溶剂热法合成了系列LiMn1-xFexPO4(x=0.15、0.25、0.35、0.45)微纳颗粒,随后采用热分解的方法对微纳颗粒进行碳包覆处理。采用X射线衍射仪(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscope,SEM)对微纳颗粒进行表征,结果可知所获微纳颗粒均为橄榄石结构,而LiMn0.75Fe0.25PO4/C分散性较好,颗粒大小较均匀。与LiFePO4/C正极材料相比,LiMn0.75Fe0.25PO4/C的导电性、放电电压、循环稳定性和储锂性能均有明显提高。LiMn0.75Fe0.25PO4/C充放电电压平台为4.1V;在0.5C的电流密度下,首次放电比容量为160mA·h/g,在100圈循环后容量依然保持在140mA·h/g;在10C的电流密度下,保持了60mA·h/g的容量。该文对于研究和发展新型可替代LiFePO4的锂离子电池正极材料具有重要的意义。展开更多
基金Supported by National Natural Science Foundation of China(No.10675118,and No.11175173)
文摘In this paper,in order to stabilize the position and angle of the light source point,a new photon beam position feedback system based on the Photon Beam Position Monitors was developed on Hefei Light Source,and used to correct the position drift and angle variation of the light source at the same time.On introducing the feedback principle,the transfer function matrix is calibrated,indicating that the new system is workable and effective.
基金Supported by the National Science Foundation of China (10675118, 11175173)
文摘As an important part of the beam diagnostic system, the synchrotron light beam position measurement has a very high value in the high quality and high stability light source applied research. A new photon beam position monitor based on position-sensitive detector (PSD) has been developed to measure the photon beam position in vertical and horizontal directions at the same time at HLS (Hefei Light Source). The new PBPM based on the PSD has fast response speed, high sensitivity and wide dynamic range. This PBPM system also includes the C4674 signal processing circuit, NI USB-9215 data acquisition device and the LABVIEW data acquisition program. This PBPM system has been calibrated vertically and horizontally on-line, and then has been applied in the beam line B3EA of HLS to measure the position of the synchrotron light. As the results shown, the resolution of the system is better than 3 mm.
基金supported by the Pri⁃mary Research&Development Plan of Jiangsu Province(Nos.BE2022070,BE2022070-2).
文摘For high-voltage and high-power Gallium Nitride(GaN)power amplifiers,a drain modulation circuit with rapid rise and fall time is proposed in this paper.To decrease the rise and fall time,the high-side bootstrap drive circuit with an auxiliary discharge switch is proposed.The effect of the parasitics is analyzed based on calculation and the parallel bonding is proposed.The storage capacitance of power supply is calculated quantitatively to provide large pulse current.To ensure safe operation of the power amplifier,the circuit topology with the dead-time control and sequential control is proposed.Finally,a prototype is built to verify the drain modulation circuit design.The experiments prove that the rise time and fall time of the output pulse signal are both less than 100 ns.
文摘文章首先采用溶剂热法合成了系列LiMn1-xFexPO4(x=0.15、0.25、0.35、0.45)微纳颗粒,随后采用热分解的方法对微纳颗粒进行碳包覆处理。采用X射线衍射仪(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscope,SEM)对微纳颗粒进行表征,结果可知所获微纳颗粒均为橄榄石结构,而LiMn0.75Fe0.25PO4/C分散性较好,颗粒大小较均匀。与LiFePO4/C正极材料相比,LiMn0.75Fe0.25PO4/C的导电性、放电电压、循环稳定性和储锂性能均有明显提高。LiMn0.75Fe0.25PO4/C充放电电压平台为4.1V;在0.5C的电流密度下,首次放电比容量为160mA·h/g,在100圈循环后容量依然保持在140mA·h/g;在10C的电流密度下,保持了60mA·h/g的容量。该文对于研究和发展新型可替代LiFePO4的锂离子电池正极材料具有重要的意义。
