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山荆子叶脉序的研究 被引量:8
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作者 王雷宏 汤庚国 +1 位作者 夏海武 蔡华 《南京林业大学学报(自然科学版)》 CAS CSCD 北大核心 2008年第2期39-42,共4页
观察了自然分布于9个省共13个山荆子标本的叶片脉序,并把脉序的各种式样与现有的叶脉序描述术语和图进行了对照。结果表明:现有的术语不能对山荆子叶脉准确描述,但从其二级脉的整体行为来看,仍可划入环结脉。脉序的类型稳定,不同地方居... 观察了自然分布于9个省共13个山荆子标本的叶片脉序,并把脉序的各种式样与现有的叶脉序描述术语和图进行了对照。结果表明:现有的术语不能对山荆子叶脉准确描述,但从其二级脉的整体行为来看,仍可划入环结脉。脉序的类型稳定,不同地方居群的代表样又有一定的特点,可以作为山荆子鉴定和分类的依据。山荆子脉序类型与湖北海棠极为相似,表明二者亲缘关系较近,主要区别在于二者细小二级脉不同。 展开更多
关键词 山荆子 叶脉脉序 环结脉
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Dynamics of a stage-structured single population system with winter hibernation and impulsive effect in polluted environment 被引量:1
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作者 Jianjun Jiao Shaohong Cai +1 位作者 Yujuan Zhang Limei Li 《International Journal of Biomathematics》 2016年第5期277-294,共18页
In this work, we construct a stage-structured single population system with winter hiber- nation and impulsive effect in polluted environment. All solutions of the investigated system are proved to be uniformly ultima... In this work, we construct a stage-structured single population system with winter hiber- nation and impulsive effect in polluted environment. All solutions of the investigated system are proved to be uniformly ultimately bounded. The conditions of the population- extinction solution of the investigated system are obtained. The permanent condition of the investigated system is also obtained. Finally, numerical analysis is inserted to illustrate the results. Our results indicate that the environmental pollution will reduce biological diversity of the natural world. Our results also provide reliable tactic basis for the practical biological resource management. 展开更多
关键词 Stage-structured single population system winter hibernation impulsive effect population-extinction permanence.
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