种植密度对决定菠萝产量起着重要的作用,高种植密度能提高每公项产量(Cha-dha等,1973;Norman,1978;Dass等,1978).种植密度不影响菠......

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随着科学技术的发展,战场上会不断出现新目标,传统目标的防护能力也会得到不断加强.钢筋混凝土永备工事的侵彻与破坏机理是21世纪......

指出了顽拗性种子的分布与植物所属的科、属并无必然的关联,故其物种数量并无确切数字。根据英国皇家植物园(邱园)种子数据,依照AP......

Definition and ornamental characteristics of ornamental grasses,as well as a general background of Kew Gardens were intr......

This paper aims to briefly summarize the major differences in form, techniques and characterization between modern ficti......

In the novella Seize the Day Saul Bellow compacts the significance of the whole life of a person into one day’s experie......