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二维正方晶格光控太赫兹波调制器 总被引：4，自引：2，他引：2
2006年冬季在南京北郊盘城利用系留气球探测系统、自动气象站等仪器对雾日和非雾日的边界层进行了监测,对比分析了两者的边界层结构。结果表明,非雾日主要为单层贴地逆温,并时常出现短时的双层结构,雾发展成熟时逆温则脱离地面。与非雾日相比,雾日平均雾顶之上温度日较差增大,雾顶之下则减小。平均风速的时间—高度分布在雾日和非雾日类似,在稳定性边界层中风速随高度出现一个或者两个极大值区。温度和比湿在非雾日没有显著的对应性,而在雾体内具有较好的对应关系,在雾顶升降过程中反相关。较强的逆温、较低的温度和较小的近地层风速是南京冬季成雾的背景条件。 相似文献
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技术创新效率提升对促进新疆工业经济转型升级具有重要意义。为了明确新疆工业技术创新活动的绩效特点,采用三阶段DEA模型以及地级行政区的大中型工业企业数据,测度并分析了新疆工业创新效率及其影响因素、区际差异。2008年以来,各区域工业创新活动普遍缺乏DEA有效性,规模效率低下是主要原因;经济市场化、产业集聚都有利于区域工业创新效率提升,但人力资本积累表现为反向作用,FDI和出口的影响不显著;剔除环境效应和统计噪音后,工业创新效率分布呈现"北疆高于南疆、核心区高于外围区"的空间极化格局。 相似文献
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The experiment system of 1000 m deep sea mining system is built up with the similarity theory.Sine mechanism is used to simulate mining ship to generate lateral shock excitation by ocean wave.Simulation and experiment of spherical joint connecting deep sea mining system has been done in band six marine conditions.The results indicate that the moment of spherical joint connecting deep sea mining is smaller than that of the thread connected ones,the lifting pipe of spherical joint is "flexible pipe".The flexural torque of the articulated lifting pipe system in pump and buffer is generally periodic variation with some irregularity,the value is stable on 60 N·S,and it is obviously smaller than that of the fixed lifting pipe system;The total displacement exhibits cyclic variation pattern,and the periodicity of them is longer than that of sea current.The results of experiment and simulation are basically consistent.And the analysis in the paper offers theoretical foundation of 1000 m deep sea mining system in China. 相似文献
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