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质量较轻的小型航行体在近水面运动时易受波浪力干扰,影响运动稳定性和控制精度,为抑制干扰,在建立纵向平面动力学模型的基础上,采用H∞混合灵敏度鲁棒控制方法设计了小型航行体近水面纵向运动控制器,建立了近水面波浪力模型,并结合所建立的波浪力模型进行了小型航行体纵向运动控制的数学仿真和半实物仿真实验研究. 结果表明,所设计的控制器调整时间短,超调小,鲁棒性较强,可较好地解决小型航行体近水面航行时的波浪干扰问题,为小型航行体总体控制系统设计提供参考依据. 相似文献
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Gambogic acid(GA) is a natural substance with a good antitumor effect, but it is too lipophilic to be metabolized and excreted, thus accumulating in the body. Gemcitabine(GEM), one of the first-line antitumor drugs, has high hydrophilicity, which greatly shortens its half-life in vivo. We previously reported a compound named N-gamboyl gemcitabine(GAG), derived from the condensation of GEM and GA, whose hydrophilicity is better than GA and stability is better than GEM. Here, the antitumor perform... 相似文献
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In order to make the synthetic route of Thiamidol more efficient and easier to scale up, a new method was developed. The compound 2,4-dihydroxyacetophenone was dissolved in ethyl acetate and brominated with cupric bromide. After bromination, the mixture was filtered to remove cuprous bromide. The obtained ethyl acetate solution containing 2-bromo-1-(2,4-dihydroxyphenyl)ethanone was directly reacted with(2-methylpropanoyl)thiourea to obtain the precipitate of Thiamidol hydrobromide. The precipita... 相似文献
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以水中弹药对水面目标进行高效攻击为背景,提出了一种水中弹药垂直攻击目标的变结构导引方法,通过假设忽略目标的横滚与纵向的机动,假设目标在水平面内作匀速直线运动,同时假设弹体无横滚,建立了水中弹药运动学模型方程、动力学模型方程及变结构垂直导引与控制. 应用Matlab/Simulink软件搭建了数学仿真系统并对水中灵巧弹药变结构垂直导引进行了闭环系统仿真研究,结果表明,所提出的水中弹药变结构垂直导引攻击目标的设计方法能够适应垂直攻击目标的设计要求,与预期的指标要求吻合良好. 相似文献
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1 INTRODUCTION Halenia elliptica which is believed to have anti- virus activity[1] has been long used as a medicinal herb to cure hepatic diseases in Qinghai-Tibetan plateau. In this study we aimed at identifying bioactive compounds from the plant. Four … 相似文献