canopy cover 中文意思是什麼
canopy cover
解釋
林冠復被-
Mongolica young stand, secondary natural forest, and the mixed forest of larix olgensis and fraxinus mandshurica rupr. countermeasures for controlling soil degradation were also recommended. the study got following results : ( 1 ) from young stand to mid - age of larix olgensis, with the closure of canopy and the decrease of undergrowth vegetation cover, soil acidity, enzyme activity, total inorganic phosphorus, available k, soil moisture and total porosity decreased significantly ; while soil organic matter content, humus component content, the amount of three main types of microbes, acid phosphatase activity, and bulk density in rhizosphere soil and non - rhizosphere soil increased with the increase of the amount of forest floor litter ; from mid - age stand to near mature stand, with the decrease of stand density and crown cover as well as the restoration of undergrowth vegetation after preliminary thinning, soil organic matter content, fulvic acid, exchangeable acidity, exchangeable aluminium, neutral phosphatase activity, total amount of inorganic phosphorus, the amount of actinomycetes, soil moisture, and total porosity in rhizosphere soil and non - rhizosphere soil apparently increased ; from near matu re stand to mature stand, soil activity acidity, organic matter content, humus component content, available phosphorus, total amount of amino acid, available k, soil enzyme activity, soil moisture, and total porosity in rhizosphere soil and non - rhizosphere soil decreased, but total phosphorus, soil acidity ( in particular, exchangeable aluminium ), and bulk density increased
結果表明： （ 1 ）從落葉松幼齡林到中齡林，隨著林冠的郁閉和林下植被蓋度的急劇下降，林地土壤酸度、土壤酶活性、無機磷總量、速效鉀、土壤水分含量、總孔隙度呈明顯下降趨勢，而根際和非根際土壤有機質含量、腐殖質各組分含量、三大類微生物數量、酸性磷酸酶活性和土壤容重隨著凋落物的增加呈明顯上升趨勢；從中齡林到近熟林，由於撫育間伐，林分密度及郁閉度下降，林下植被蓋度逐步得到恢復，根際與非根際土壤有機質含量、富里酸、交換性酸、交換性鋁、中性磷酸酶、無機磷總量、放線菌數量、土壤水分含量、總孔隙度呈明顯的上升趨勢；從近熟林到成熟林，隨著林齡的增大，根際與非根際土壤活性酸、有機質含量、腐殖質各組分含量、有效磷含量、氨基酸總量、速效鉀、土壤酶的活性、土壤水分含量和總孔隙度呈下降趨勢，而根際與非根際土壤全磷含量、土壤酸度（特別是交換性鋁）和容重呈增加趨勢。 -
Firstly, this paper summarizes modern weaponry stealth technology at home and abroad, and lays special emphasis on analyzing stealth problem of cruise missile ’ s guidance head cover, aerocraft radar canopy and other privileged sites. secondly it makes a research on related theories of transparent metallic mesh that applied to missile ’ s guidance head cover and aerocraft radar canopy, and deduces relational expression between transparent metallic mesh structural parameters and radar wave - shielding efficiency, infrared transmitting. we use laser direct writing technique to fabricate a metallic mesh ( dimension : 70mm 70mm ; line width : 5 m ; period : 350 m ) on glass surface, then do experiment to test radar wave - shielding of metallic mesh via radar transmitting and receiving device
本文首先綜述了國內外現代武器系統隱身技術方法;重點對巡航導彈導引頭罩和飛機雷達艙罩等特殊部位的隱身問題進行了研究，研究了金屬網柵用於導彈頭罩和飛機雷達艙罩隱身的相關理論，推導了金屬網柵結構參數對雷達波屏蔽效率和透紅外關系式;用激光直寫工藝，在玻璃表面上製作了一塊面積為70mm 70mm ，線寬為5 m ，線周期為350 m的金屬網柵;在實驗室里用雷達發射和接收裝置測試了網柵對雷達波的屏蔽實驗;認為利用金屬網柵技術對雷達波具有一定的屏蔽作用，而且不影響精確制導的紅外線高效透過。 -
During the day, the walls are transparent and full of light. at night, accordion - style doors unfold to cover everything. the ceiling has a row of thin, elegant skylights, with a graceful transparent canopy over the window
這真是世上最美的一間鳥舍-白天時，四面墻壁是透明的，陽光充裕到了夜晚，只要將一扇折疊式拉門拉開來，就可以發揮很好的遮掩效果天花板上有一排雅緻的薄天窗，天窗上方則覆蓋著一層典雅的透明罩。
分享友人