An experimental device is used to study the characteristics of dielectric barrier discharge(DBD)plasma excited by high voltage sub-microsecond pulse power in atmospheric air.Glass,polytetrafluoroethene(PTFE)and plexig...An experimental device is used to study the characteristics of dielectric barrier discharge(DBD)plasma excited by high voltage sub-microsecond pulse power in atmospheric air.Glass,polytetrafluoroethene(PTFE)and plexiglass are used as dielectric barrier materials.Comparatively homogeneous discharge is obtained within 130 mm diameter area in atmospheric air using the three dielectric materials with gap distances of 4.5 mm,6.5 mm and 6.5 mm,respectively.There is no filamentary discharge observed by naked eyes or by camera with the exposure time of 0.25 s.Gas gap voltage,discharge current,discharge power density,etc.are calculated by using Liu’s equivalent circuit model for pulsed DBD.These parameters are used to study the DBD characteristics.Typically,current varies from tens of amperes to hundreds of amperes in atmospheric air DBD excited by sub-microsecond pulses.The peak power can reach to MW order of magnitude.The average power surface density of 1.0 W/cm2and the average electron density of 1011cm 3can also be obtained in the discharge.Rotational and vibrational temperatures,approximately 400 K and 2 650 K,respectively,are obtained by using the emission spectrum of the discharge.This is the basic work performed for a better understanding of the characteristics of atmospheric air DBD plasma excited by high voltage sub-microsecond pulsed power source.展开更多
Elucidating the initial kinetics of folding pathways is critical to the understanding of the protein folding mechanism. Transient infrared spectroscopy has proved a powerful tool to probe the folding kinetics. Herein ...Elucidating the initial kinetics of folding pathways is critical to the understanding of the protein folding mechanism. Transient infrared spectroscopy has proved a powerful tool to probe the folding kinetics. Herein we report the construction of a nanosecond laser-induced temperature-jump （T-jump） technique coupled to a nanosecond timeresolved transient mid-infrared （mid-IR） spectrometer system capable of investigating the protein folding kinetics with a temporal resolution of 50 ns after deconvolution of the instrumental response function. The mid-IR source is a liquid N2 cooled CO laser covering a spectral range of 5.0μm （2000 cm^-1）-6.5μm （1540 cm^-1）. The heating pulse was generated by a high pressure H2 Raman shifter at wavelength of 1.9μm. The maximum temperature-jump could reach as high as 26±1℃. The fast folding/unfolding dynamics of cytochrome C was investigated by the constructed system, providing an example.展开更多
为提升操作系统的实时性,对PPC460处理器进行硬件加速处理。采用FPGA对PPC460处理器架构进行核心代码移植,修改原有SRAM空间为DPRAM并进行加固处理,增加任务控制块(task control block,TCB)模块精准定位和监控任务状态及堆栈信息,在操...为提升操作系统的实时性,对PPC460处理器进行硬件加速处理。采用FPGA对PPC460处理器架构进行核心代码移植,修改原有SRAM空间为DPRAM并进行加固处理,增加任务控制块(task control block,TCB)模块精准定位和监控任务状态及堆栈信息,在操作系统发生任务调度时,将原有串行压栈出栈模式修改为并行同时进出栈模式。测试结果表明:该方法有效实现了针对PPC460处理器的任务切换亚微秒设计,处理复杂应用的实时性与抗干扰能力得到极大提升。展开更多
Sub-microsecond time-resolved absorption spectroscopy has been used to study the electronically excited state behavior of soluble multiwalled carbon nanotube (MWNTsCON((CH2)9- CH3)2, denoted as MDDA) in chloroform, to...Sub-microsecond time-resolved absorption spectroscopy has been used to study the electronically excited state behavior of soluble multiwalled carbon nanotube (MWNTsCON((CH2)9- CH3)2, denoted as MDDA) in chloroform, toluene and cyclohexane. Following pulsed photo-excitation of MDDA at 355 nm, three major spectral components are clearly identified with the help of global analysis carried out over 7 representative kinetics curves from 450 to 700 nm. The solvent depend-ence of decay associated difference spectra (DADS) and the corresponding lifetimes help to assign these transient species to singlet state (S1), triplet state (T1) and charge-separated state (CS), re-spectively. Preliminary discussion had been made to explore the involved photophysical and electron transfer processes.展开更多
基金Project supported by National Natural Science Foundation of China（11035004）, Double Hundred Talent Fotmdation of CAEP （ 2009R0102）, Key Laboratory of Pulsed Power of CAEP Science and Technology Development Foundation （2008B0402037）.
文摘An experimental device is used to study the characteristics of dielectric barrier discharge(DBD)plasma excited by high voltage sub-microsecond pulse power in atmospheric air.Glass,polytetrafluoroethene(PTFE)and plexiglass are used as dielectric barrier materials.Comparatively homogeneous discharge is obtained within 130 mm diameter area in atmospheric air using the three dielectric materials with gap distances of 4.5 mm,6.5 mm and 6.5 mm,respectively.There is no filamentary discharge observed by naked eyes or by camera with the exposure time of 0.25 s.Gas gap voltage,discharge current,discharge power density,etc.are calculated by using Liu’s equivalent circuit model for pulsed DBD.These parameters are used to study the DBD characteristics.Typically,current varies from tens of amperes to hundreds of amperes in atmospheric air DBD excited by sub-microsecond pulses.The peak power can reach to MW order of magnitude.The average power surface density of 1.0 W/cm2and the average electron density of 1011cm 3can also be obtained in the discharge.Rotational and vibrational temperatures,approximately 400 K and 2 650 K,respectively,are obtained by using the emission spectrum of the discharge.This is the basic work performed for a better understanding of the characteristics of atmospheric air DBD plasma excited by high voltage sub-microsecond pulsed power source.
基金Project supported by the National Natural Science Foundation of China （Grant No 20373088） and Program for innovation group （Grant No 60321002）.
文摘Elucidating the initial kinetics of folding pathways is critical to the understanding of the protein folding mechanism. Transient infrared spectroscopy has proved a powerful tool to probe the folding kinetics. Herein we report the construction of a nanosecond laser-induced temperature-jump （T-jump） technique coupled to a nanosecond timeresolved transient mid-infrared （mid-IR） spectrometer system capable of investigating the protein folding kinetics with a temporal resolution of 50 ns after deconvolution of the instrumental response function. The mid-IR source is a liquid N2 cooled CO laser covering a spectral range of 5.0μm （2000 cm^-1）-6.5μm （1540 cm^-1）. The heating pulse was generated by a high pressure H2 Raman shifter at wavelength of 1.9μm. The maximum temperature-jump could reach as high as 26±1℃. The fast folding/unfolding dynamics of cytochrome C was investigated by the constructed system, providing an example.
文摘为提升操作系统的实时性,对PPC460处理器进行硬件加速处理。采用FPGA对PPC460处理器架构进行核心代码移植,修改原有SRAM空间为DPRAM并进行加固处理,增加任务控制块(task control block,TCB)模块精准定位和监控任务状态及堆栈信息,在操作系统发生任务调度时,将原有串行压栈出栈模式修改为并行同时进出栈模式。测试结果表明:该方法有效实现了针对PPC460处理器的任务切换亚微秒设计,处理复杂应用的实时性与抗干扰能力得到极大提升。
基金This work was supported by the National Natural Science Foundation of China (Grant No. 20373079).
文摘Sub-microsecond time-resolved absorption spectroscopy has been used to study the electronically excited state behavior of soluble multiwalled carbon nanotube (MWNTsCON((CH2)9- CH3)2, denoted as MDDA) in chloroform, toluene and cyclohexane. Following pulsed photo-excitation of MDDA at 355 nm, three major spectral components are clearly identified with the help of global analysis carried out over 7 representative kinetics curves from 450 to 700 nm. The solvent depend-ence of decay associated difference spectra (DADS) and the corresponding lifetimes help to assign these transient species to singlet state (S1), triplet state (T1) and charge-separated state (CS), re-spectively. Preliminary discussion had been made to explore the involved photophysical and electron transfer processes.
