介绍了一种用于丝阵Z箍缩(Z-pinch)内爆实验研究的脉冲放电模块的设计。模块基于直线型变压器驱动器(LTD)技术,包含34个放电支路,通过4个铁基非晶磁芯耦合。每支路由2个40nF电容器和1只4间隙串联气体开关组成,回路电感为220nH。设计了...介绍了一种用于丝阵Z箍缩(Z-pinch)内爆实验研究的脉冲放电模块的设计。模块基于直线型变压器驱动器(LTD)技术,包含34个放电支路,通过4个铁基非晶磁芯耦合。每支路由2个40nF电容器和1只4间隙串联气体开关组成,回路电感为220nH。设计了水电阻负载检验模块输出性能,在匹配状态下,负载上的输出电流峰值916 k A,上升时间99.8 ns。设计了磁绝缘传输线将输出脉冲传输至Z-pinch丝阵负载,并利用"零维模型"对LTD模块和负载的耦合放电进行了模拟计算。结果显示,丝阵负载上的放电电流峰值可达960 k A,上升时间为114 ns。展开更多
This paper introduces a real option approach to valuation of oil companies and uses the real option pricing model to value CNOOC Ltd. at the time of its IPO. The empirical result shows that the option pricing value of...This paper introduces a real option approach to valuation of oil companies and uses the real option pricing model to value CNOOC Ltd. at the time of its IPO. The empirical result shows that the option pricing value of CNOOC Ltd. exceeds its IPO price at about 21%.展开更多
Based on a transmission line code, a circuit model is proposed that could serve as the basic method for the analysis of linear transformer driver （LTD）-based accelerators. By using 1 MA, 100 kV LTD cavities, the pea...Based on a transmission line code, a circuit model is proposed that could serve as the basic method for the analysis of linear transformer driver （LTD）-based accelerators. By using 1 MA, 100 kV LTD cavities, the peak load current is optimized for a total of N cavities between 500 and 1200. The simulation results suggest that, with the same number of cavities, the peak current changes obviously with the types of combinations, and the maximum change can be as large as 1.2 MA. The results also show that, for the cases considered, the optimized peak current as a function of the total number of cavities agrees with the exponential associate, and the peak current for one level LTD cannot be enhanced infinitely. Furthermore, it is found that, to obtain a 20 MA peak load current, at least 1029 LTD cavities （49 in series and 21 in parallel connection） are needed. Finally, the typical parameters of the optimized design are compared to those of the existing Z accelerator.展开更多
The pests, diseases and weeds in sugarcane areas of Lincang Nanhua Sugar Industry Co.,Ltd. were investigated at seedling stage, growth stage and maturity stage of sugarcane from 2012 to 2016. The occurrence and damag...The pests, diseases and weeds in sugarcane areas of Lincang Nanhua Sugar Industry Co.,Ltd. were investigated at seedling stage, growth stage and maturity stage of sugarcane from 2012 to 2016. The occurrence and damage of diseases, pests and weeds were analyzed, and the problems in prevention and control were discussed based on the local conditions of sugarcane production. The species, occurrence and damage characteristics of diseases, pests and weeds were ascertained, and the corresponding strategies and technical measures were proposed.展开更多
文摘介绍了一种用于丝阵Z箍缩(Z-pinch)内爆实验研究的脉冲放电模块的设计。模块基于直线型变压器驱动器(LTD)技术,包含34个放电支路,通过4个铁基非晶磁芯耦合。每支路由2个40nF电容器和1只4间隙串联气体开关组成,回路电感为220nH。设计了水电阻负载检验模块输出性能,在匹配状态下,负载上的输出电流峰值916 k A,上升时间99.8 ns。设计了磁绝缘传输线将输出脉冲传输至Z-pinch丝阵负载,并利用"零维模型"对LTD模块和负载的耦合放电进行了模拟计算。结果显示,丝阵负载上的放电电流峰值可达960 k A,上升时间为114 ns。
文摘This paper introduces a real option approach to valuation of oil companies and uses the real option pricing model to value CNOOC Ltd. at the time of its IPO. The empirical result shows that the option pricing value of CNOOC Ltd. exceeds its IPO price at about 21%.
基金supported by National Natural Science Foundation of China(Nos.50637010,5107711)
文摘Based on a transmission line code, a circuit model is proposed that could serve as the basic method for the analysis of linear transformer driver （LTD）-based accelerators. By using 1 MA, 100 kV LTD cavities, the peak load current is optimized for a total of N cavities between 500 and 1200. The simulation results suggest that, with the same number of cavities, the peak current changes obviously with the types of combinations, and the maximum change can be as large as 1.2 MA. The results also show that, for the cases considered, the optimized peak current as a function of the total number of cavities agrees with the exponential associate, and the peak current for one level LTD cannot be enhanced infinitely. Furthermore, it is found that, to obtain a 20 MA peak load current, at least 1029 LTD cavities （49 in series and 21 in parallel connection） are needed. Finally, the typical parameters of the optimized design are compared to those of the existing Z accelerator.
基金Supported by Special Fund for China Agricultural Industry Research System(CARS-170303)Special Fund for Agricultural Industry Research System of Yunnan Province(YNGZTX-4-92)
文摘The pests, diseases and weeds in sugarcane areas of Lincang Nanhua Sugar Industry Co.,Ltd. were investigated at seedling stage, growth stage and maturity stage of sugarcane from 2012 to 2016. The occurrence and damage of diseases, pests and weeds were analyzed, and the problems in prevention and control were discussed based on the local conditions of sugarcane production. The species, occurrence and damage characteristics of diseases, pests and weeds were ascertained, and the corresponding strategies and technical measures were proposed.
