Dynamics of endogenous hormone in american ginseng seed during morphological after - ripening period and their regulation to embryo development 西洋參種胚形態后熟過程中種子內源激素變化動態及其對種胚發育的調節
Karst ecosystem is a kind of vulnerable ecosystem , its vulnerability including mainly : 1 environment capacity is small , vegetation is difficult to recover after having been destructed , hydrologic movement is rapid and floods and droughts often occur ; 2 vegetation growth depends on the conditions of eco - environment overly , which are affected by environment obviously ; 3the positive evolve of eco - environment relies on the recover of vegetation , 4the methods of water resource use and land use lack of rationality . these vulnerabilities are be magnified by climate changes 巖溶生態系統是一種脆弱的生態系統,它的脆弱性主要表現在:環境容量小,植被遭破壞后很長時間才能恢復,以及水文過程變化迅速,旱澇時常發生;植被生長過度依賴于生境條件,但生境條件受到環境影響明顯;生態環境的良性演化依賴植被的恢復;水資源利用與土地利用方式間缺乏合理性,如刀耕火種、過渡開墾造成生態環境中種子庫嚴重丟失,物種多樣性受到影響,植被演化趨于單一或種群退化。
The main context of this paper is improving the precision of the disseminator . through analyzing the motion and construction parameter , making sure of the factor of working property , the motion equations of seed were established , and then the mathematical patter of main parameters were established . using of vb , we compiled procedure to simulate the motion of seed in the working process , finding the main factor that affect on the working property of the disseminator , then optimal designing of parameters of the device was laid 通過對排種輪的充種極限速度、清種始角、護種始角、排種器的投種口尺寸、型孔的尺寸等運動參數和結構參數進行分析,總體了解排種器結構參數和運動參數對其工作性能的影響,建立種子的運動方程,進而建立各主要參數(充種速度、清種角、護種角等)的數學模型,運用計算機輔助分析( caa )方法,通過visualbasic編制程序,對排種器工作過程中種子的運動進行動態模擬,找出影響排種器工作性能的主要因素,并對其參數進行優化,為合理地優化設計奠定了基礎。
Based on analysis of the forces exerted to seeds in metering device during working procedure , the theoretical calculation equations for beginning and end angles of seed cleaning in scoop metering device with declined disc were established , and the impact of construction and working parameters on seed filling and cleaning were investigated 摘要以排種器工作過程中種子的受力分析為基礎,建立了排種器清種起始角和清種結束角的理論計算公式,分析了傾斜圓盤勺式精密排種器結構參數和工作參數對充種和清種性能的影響。