为了节省棉花打顶用工,达到轻简化栽培目的。通过以中熟陆地棉品系豫宛199为材料,在豫南植棉区进行新型化学打顶剂打顶试验,研究打顶剂不同喷施时间、不同剂量对棉花顶端控制及产量的影响。结果表明:两个喷施时期的3种剂量均可控制棉花...为了节省棉花打顶用工,达到轻简化栽培目的。通过以中熟陆地棉品系豫宛199为材料,在豫南植棉区进行新型化学打顶剂打顶试验,研究打顶剂不同喷施时间、不同剂量对棉花顶端控制及产量的影响。结果表明:两个喷施时期的3种剂量均可控制棉花顶端生长速度和增加籽棉产量,8月3日喷施的对棉花顶端控制效果好于8月8日,株高新增量随剂量的升高而降低,果枝数新增量剂量之间差异不明显,籽棉产量以处理3比人工打顶对照增产显著。对于豫南植棉区的中熟棉,在8月3日使用新型化学打顶剂750 m L/hm2进行打顶可以有效抑制棉花顶部生长,控制效果接近人工打顶。展开更多
In this paper, the law of roof-coal movement has been investigated through the field measurement, theoretical analysis and numerical calculation. Several results, which are of important values for caving process, desi...In this paper, the law of roof-coal movement has been investigated through the field measurement, theoretical analysis and numerical calculation. Several results, which are of important values for caving process, design of the supports, controlling end-face stability, raising recovery rate, realizing working face high output and other related aspects in practice, have been obtained. These results mainly include the following: roof-coal breaking curve of soft-coal seam, roof-coal movement curve of soft-coal and medium-hard coal seam, and roof-coal movement equation. The roof-coal caveability has been analyzed.展开更多
Plant organs are derived from stem cells.Once a leaf primordium initiates growth from the shoot apical meristem（SAM）,it establishes adaxial-abaxial（dorsal-ventral）polarity.This polarity essentially allows the leaf...Plant organs are derived from stem cells.Once a leaf primordium initiates growth from the shoot apical meristem（SAM）,it establishes adaxial-abaxial（dorsal-ventral）polarity.This polarity essentially allows the leaf to become a flat structure with the lamina expanding along the juxtaposition,i.e.,the middle domain,between the adaxial and abaxial domains.展开更多
文摘为了节省棉花打顶用工,达到轻简化栽培目的。通过以中熟陆地棉品系豫宛199为材料,在豫南植棉区进行新型化学打顶剂打顶试验,研究打顶剂不同喷施时间、不同剂量对棉花顶端控制及产量的影响。结果表明:两个喷施时期的3种剂量均可控制棉花顶端生长速度和增加籽棉产量,8月3日喷施的对棉花顶端控制效果好于8月8日,株高新增量随剂量的升高而降低,果枝数新增量剂量之间差异不明显,籽棉产量以处理3比人工打顶对照增产显著。对于豫南植棉区的中熟棉,在8月3日使用新型化学打顶剂750 m L/hm2进行打顶可以有效抑制棉花顶部生长,控制效果接近人工打顶。
文摘In this paper, the law of roof-coal movement has been investigated through the field measurement, theoretical analysis and numerical calculation. Several results, which are of important values for caving process, design of the supports, controlling end-face stability, raising recovery rate, realizing working face high output and other related aspects in practice, have been obtained. These results mainly include the following: roof-coal breaking curve of soft-coal seam, roof-coal movement curve of soft-coal and medium-hard coal seam, and roof-coal movement equation. The roof-coal caveability has been analyzed.
文摘Plant organs are derived from stem cells.Once a leaf primordium initiates growth from the shoot apical meristem（SAM）,it establishes adaxial-abaxial（dorsal-ventral）polarity.This polarity essentially allows the leaf to become a flat structure with the lamina expanding along the juxtaposition,i.e.,the middle domain,between the adaxial and abaxial domains.
