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不同碳氮浓度对雨生红球藻生长及虾青素累积的影响 总被引：1，自引：0，他引：1
研究了不同二氧化碳浓度和硝酸钾浓度对雨生红球藻生长及虾青素累积的影响。结果表明,较高浓度的CO2(600×10-6)能够显著促进雨生红球藻的生长、光合作用的进行和虾青素的累积。红球藻单个细胞内的虾青素含量随着培养液中硝酸钾浓度的降低而增加,绿色游动藻种和绿色不动藻种培养12 d后获得的最大虾青素值分别为10.93 pg/个和12.64 pg/个。连续通气是促进雨生红球藻生长及虾青素累积的一种有效碳源提供方式。 相似文献
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落石冲击作用下被动柔性防护网整体结构试验 总被引：4，自引：0，他引：4
针对被动柔性防护网受力系统,介绍了被动柔性防护网在国内外的应用和研究现状,阐明了被动柔性防护网的构成和传力机理,揭示其抵抗落石冲击的基本原理。为分析被动柔性防护网整体受力机理和响应特点,进行了在落石作用下被动柔性防护网足尺模型的冲击试验,分析了被动柔性防护网受到冲击之后的整体变形以及减压环、钢柱等关键构件的耗能及其破坏机理,为被动柔性防护网的结构计算分析与设计提供一定的参考依据。 相似文献
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There are many reports about the research on near-fault velocity pulses, which focus on the generation of velocity pulse and simplify the velocity pulse so as to be used in the seismic design of structure, However few researches have put emphasis on the characteristics of near-fault ground motions containing velocity pulses, especially the characteristics relevant with the design response spectrum prescribed by the code. Through collection of a large number of near-fault records containing velocity pulses, the response spectra and the characteristic periods of records containing no pulses are compared with those of records containing pulses. Response spectra of near-fault records are compared with standard spectra given by code; furthermore, the response spectra and the characteristic periods of each earthquake are compared with that given by code. The result shows that at long periods （longer than 1.5 s）, the response spectrum of pulse-containing records is bigger than the response spectrum of no-pulse-containing records; when the characteristic period of near-fault records is calculated, the method that does not fix frequency is more reasonable because the T1 and T2 have a lagging tendency; regardless of the site Ⅰ and site Ⅱ, the characteristic period of pulse-containing records is over twice bigger than the characteristic period given by the code, 相似文献
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在搜集了大量近断层具有速度脉冲的记录后，对有速度脉冲和无速度脉冲的记录的反应谱和特征周期进行了对比，将近断层记录的反应谱与我国规范标准反应谱进行了比较， 还将各次地震有速度脉冲记录的反应谱和特征周期与规范标准谱及规范给出的特征周期进行了比较. 通过比较可知，在长周期段（大约在1.5 s以后），有速度脉冲记录的反应谱值要比无速度脉冲记录的反应谱值大；计算特征周期时，对于近断层记录，T1和T2有后延的趋势， 采用不固定频段的方法计算更加合理； 无论是相对我国规范的Ⅰ类还是Ⅱ类场地， 有速度脉冲记录的特征周期比规范中给出的值都要大，均在规范值的2倍以上. 相似文献
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