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Observation of Periodic Multiplication and Chaotic Phenomena in Atmospheric Cold Plasma Jets 下载免费PDF全文
We investigate the temporal evolution of the current pulses from an ac Fie cold plasma jet at atmospheric pressure and with driving frequency in the range 14.76-15.30 kHz. The driving frequency is used as the plasma system's bifurcation parameter in analogy with the evolution in which the current pulses undergoes multiplication and chaos. Such time-domain nonlineaxity is important for controlling instabilities in atmospheric glow discharges. In addition, the observation can provide some data to support the simulation results reported previously [Appl. Phys. Lett. 90 (2007) 071501]. 相似文献
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古里雅冰帽气候环境记录 总被引:20,自引:0,他引:20
古里雅冰帽极低的冰温和冻结到冰床等特征决定了该冰帽贮存了理想的气候环境记录。氧同位素、微粒含量、阴离子、阳离子等参数清楚的年际和季节循环特征,是该冰帽冰芯的高分辨率时间序列的准确断代的基础。冷期时稳定氧同位素值减少、微粒含量和各被测化学元素增加,而暖期时稳定氧同位素值增大、微粒含量和各被测化学元素减少的特征以及各种突发事件记录的合理解释将是系统恢复该冰帽所记录的各种气候环境的钥匙。古里雅冰芯记录表明,80年代中后期在这里发生的气候变暖是过去几十年最强烈的一次。 相似文献
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A superconducting squeezed type half-wave resonator (HWR) of β=0.09 has been developed at the Institute of Modern Physics, Lanzhou. In this paper, a basic design is presented for the stiffening structure for the detuning effect caused by helium pressure and Lorentz force. The mechanical modal analysis has been investigated the with finite element method (FEM). Based on these considerations, a new stiffening structure is proposed for the HWR cavity. The computation results concerning the frequency shift show that the low beta HWR cavity with new stiffening structure has low frequency sensitivity coefficient df/dp and Lorentz force detuning coefficient KL, and stable mechanical properties. 相似文献
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刘环环 《影像科学与光化学》2011,29(4)
<正>二芳基乙烯光致变色化合物在存储、显示、开关、防护、防伪及化学传感器等方面具有潜在的应用价值.本论文设计合成了一系列分别以2,5-二氢噻吩和咪唑为桥头的新型二芳基乙烯光致变色化合物,研究了该类化合物的光致变色性质,并探索了它们在光存储、光开关和化学传感器等方面的应用. 相似文献
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A high-repetition rate master oscillator power amplifier pumped with laser diodes (LDs) is reported. An injection seeding single-frequency electro-optical Q-switched Nd:YAG laser is used as an oscillator, and a conductively cooled Nd:YAG zigzag slab with a bounce-pumped architecture is utilized as a power amplifier. Pulse energies of over 800 mJ at 1 064 nm and 400 mJ at 532 nm, corresponding to average powers of 200 and 100 W, respectively, are achieved with a 12.6-ns pulse width at 250 Hz. Output frequency fluctuations and single-frequency operation are further monitored. Experimental results reveal that the proposed system, which features a single-pass amplified configuration, is a promising design for space-based applications. 相似文献
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考虑偶数阶非线性中立型微分方程,利用Lebesgue控制收敛定理获得了最终有界正解存在的一个充分必要条件. 相似文献
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α-Al2O3∶C单晶具有优良的热释光特性,被用做热释光剂量计,但α-Al2O3∶C晶体剂量计的形状不易加工,生产成本高且碳在晶体中难以掺杂均匀。采用低温燃烧合成法以无水乙醇为溶剂,尿素为染料,硝酸铝为反应物制备少团簇、分散均匀的片状α-Al2O3∶C陶瓷粉体。探讨不同点火温度和不同退火温度对其光致发光特性的影响,不同退火温度对热释光特性的影响以及热释光与辐射剂量(90Sr β)的关系。通过分析α-Al2O3∶C陶瓷粉体的光致发光光谱得出:α-Al2O3∶C陶瓷粉体的发射波长在395 nm附近,点火温度T≤800℃时,点火温度为500 ℃制备的α-Al2O3∶C陶瓷粉体的光致发光强度最强;在相同点火温度T=500 ℃下,经不同温度退火制备α-Al2O3∶C陶瓷粉体,点火温度为500 ℃制备的α-Al2O3∶C陶瓷粉体经1 000 ℃退火后光致发光强度最强。通过分析α-Al2O3∶C陶瓷粉体的热释光曲线得出:退火后的α-Al2O3∶C陶瓷粉体在200 ℃左右的热释光峰值占主导,900 ℃退火的α-Al2O3∶C陶瓷粉体在200 ℃附近的热释光峰值最强;通过峰高法对900 ℃高温退火处理后的α-Al2O3∶C陶瓷粉体位于200 ℃左右的热释光峰做剂量响应曲线,可以看出,在1~50 Gy剂量范围内具有良好的热释光剂量线性响应关系,在50~200 Gy剂量范围内出现超线性响应关系。与α-Al2O3∶C晶体(1~10 Gy)和多孔Al2O3∶C薄膜(1~10 Gy)相比,α-Al2O3∶C陶瓷粉体的线性剂量响应范围明显扩大。此研究可为提高氧化铝陶瓷粉体的热释光性能提供思路。 相似文献