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基于FOH的n阶积分器采样数据模型(英文)
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作者 李修云 曾诚 《机床与液压》 北大核心 2017年第24期106-112,共7页
针对一阶保持器(first-order hold,FOH)条件,分析了n阶积分器的离散采样模型,导出了相应的FOH离散脉冲函数和离散时间模型的标准形描述。在此基础上,探寻了离散时间零点的渐近性质,以及离散标准形模型的采样零点条件。特别地,当采样周期... 针对一阶保持器(first-order hold,FOH)条件,分析了n阶积分器的离散采样模型,导出了相应的FOH离散脉冲函数和离散时间模型的标准形描述。在此基础上,探寻了离散时间零点的渐近性质,以及离散标准形模型的采样零点条件。特别地,当采样周期T→0时,研究并且描述了线性n阶积分器的离散系统零点的稳定特性和稳定准则。所给出的定理是对相关结果的进一步推广。 展开更多
关键词 采样数据模型 离散系统零点 n阶积分器 一阶保持器 标准形
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Male reproductive system and simulated high-altitude environment:preliminary results in rats
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作者 xiu-yun li Mei-Hua Zhang +3 位作者 Zhao-Wen Chen Bin Zhang Gang Bai He-Feng Wang 《Asian Journal of Andrology》 SCIE CAS CSCD 2023年第3期426-432,共7页
This study assessed the effects of a simulated high-altitude environment on the reproductive system of prepubertal male rats and the reversibility of these effects upon return to a normal environment.Three-week-old ma... This study assessed the effects of a simulated high-altitude environment on the reproductive system of prepubertal male rats and the reversibility of these effects upon return to a normal environment.Three-week-old male Wistar rats were randomly allocated to 4 groups that were exposed to different conditions:a normal environment for 6 weeks and 12 weeks,respectively,hypobaric hypoxia for 6 weeks,and hypobaric hypoxia for 6 weeks followed by a normal environment for 6 weeks.Multiple pathophysiological parameters were evaluated at the histological,endocrine,and molecular levels.Hypobaric hypoxia exposure for 6 weeks during the prepubertal phase significantly altered physiological parameters,body functions,blood indices,and reproductive potential.Six weeks after returning to a normal environment,the damaged reproductive functions partially recovered due to compensatory mechanisms.However,several changes were not reversed after returning to a normal environment for 6 weeks,including disorders of body development and metabolism,increased red blood cells,increased fasting blood glucose,abnormal blood lipid metabolism,decreased testicular and epididymis weights,abnormal reproductive hormone levels,excessive apoptosis of reproductive cells,and decreased sperm concentration.In summary,a hypobaric hypoxic environment significantly impaired the reproductive function of prepubertal male rats,and a return to normal conditions during the postpubertal phase did not fully recover these impairments. 展开更多
关键词 high altitude hypobaric hypoxia male rats reproductive potential TESTIS
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