Spike train of uneven duration or delay(STUD)pulses hold potential for laser-plasma interaction(LPI)control in laser fusion.The technique based on time grating is applied to generate an STUD pulse train.Time grating,a...Spike train of uneven duration or delay(STUD)pulses hold potential for laser-plasma interaction(LPI)control in laser fusion.The technique based on time grating is applied to generate an STUD pulse train.Time grating,a temporal analogy of the diffraction grating,can control the pulse width,shape,and repetition rate easily through the use of electro-optical devices.The pulse width and repetition rate are given by the modulation frequency and depth of the phase modulation function in theory and numerical calculation.The zero-chirped phase modulation is good for the compression effect of the time grating.A principle experiment of two pulses interfering is shown to verify the time grating function.展开更多
Competition of stimulated Raman scattering was observed in hydrogen-methane mixed gases pumped by a KrF laser.The Stokespulse of methane gas oscillated,shortened and was destroyed with the addition ofvarious ratios of...Competition of stimulated Raman scattering was observed in hydrogen-methane mixed gases pumped by a KrF laser.The Stokespulse of methane gas oscillated,shortened and was destroyed with the addition ofvarious ratios of hydrogen gas.A model including the feedback of the cell windows as well as competition between hydrogen and methane gas agree well with the experimental observations.展开更多
The mechanical properties, corrosion resistance and microstructures of high performance steel （HPS） was investigated by tensile testing machine, Charpy V-Notch （CVN） testing machine, cyclic immersion corrosion tes...The mechanical properties, corrosion resistance and microstructures of high performance steel （HPS） was investigated by tensile testing machine, Charpy V-Notch （CVN） testing machine, cyclic immersion corrosion tester, XRD, optical microscopy （OM）, scanning electron microscopy （SEM）, and electron probe micro-analyzer （EPMA）. The results showed that significant differences existed in the tensile strength, yield strength and impact toughness between HPS and PCS. After 72 h cyclic immersion accelerated corrosion test, the inner rust layer on HPS was com- posed of a-FeOOH phase and denser than that on PCS that was a mixture of a-FeOOH and Fe3 04. The rust formed on HPS provides better protection and HPS has lower corrosion rates than PCS. Copper and chromium in HPS en- rich in the rust layer and enhance the compactness of the rust layer. Based on the results of the accelerated corrosion tests and rust layer analysis, the roles of Cu and Cr against corrosion are discussed, providing HPS with chemical specification which has been industrially successful to produce weathering steel for bridge structure.展开更多
基金the National Natural Science Foundation of China under Grant Nos 61138006,10905039 and 51235007.
文摘Spike train of uneven duration or delay(STUD)pulses hold potential for laser-plasma interaction(LPI)control in laser fusion.The technique based on time grating is applied to generate an STUD pulse train.Time grating,a temporal analogy of the diffraction grating,can control the pulse width,shape,and repetition rate easily through the use of electro-optical devices.The pulse width and repetition rate are given by the modulation frequency and depth of the phase modulation function in theory and numerical calculation.The zero-chirped phase modulation is good for the compression effect of the time grating.A principle experiment of two pulses interfering is shown to verify the time grating function.
基金Supported by the National Natural Science Foundation of China under Grant No.69780005.
文摘Competition of stimulated Raman scattering was observed in hydrogen-methane mixed gases pumped by a KrF laser.The Stokespulse of methane gas oscillated,shortened and was destroyed with the addition ofvarious ratios of hydrogen gas.A model including the feedback of the cell windows as well as competition between hydrogen and methane gas agree well with the experimental observations.
文摘The mechanical properties, corrosion resistance and microstructures of high performance steel （HPS） was investigated by tensile testing machine, Charpy V-Notch （CVN） testing machine, cyclic immersion corrosion tester, XRD, optical microscopy （OM）, scanning electron microscopy （SEM）, and electron probe micro-analyzer （EPMA）. The results showed that significant differences existed in the tensile strength, yield strength and impact toughness between HPS and PCS. After 72 h cyclic immersion accelerated corrosion test, the inner rust layer on HPS was com- posed of a-FeOOH phase and denser than that on PCS that was a mixture of a-FeOOH and Fe3 04. The rust formed on HPS provides better protection and HPS has lower corrosion rates than PCS. Copper and chromium in HPS en- rich in the rust layer and enhance the compactness of the rust layer. Based on the results of the accelerated corrosion tests and rust layer analysis, the roles of Cu and Cr against corrosion are discussed, providing HPS with chemical specification which has been industrially successful to produce weathering steel for bridge structure.
