b b fraction 中文意思是什麼
b b fraction
解釋
b-b餾分-
Bismuth ruthenate and silver were selected as conductor phases and the mixture of calcium oxide - alumina - silicon dioxide ( cao - al _ 2o _ 3 - sio _ 2 ) glass and lead oxide - boron oxide - silicon dioxide ( pbo - b _ 2o _ 3 - sio _ 2 ) glass was selected as inorganic binder phases. it was found that, with the increasing of volume fraction of silver and conductor phase, sheet resistivities descend and there are critical thresholds
實驗發現，隨著功能相百分含量的增加，電阻膜層的方阻值逐漸減小，存在兩個臨界閾值，電阻溫度系數偏向正值;功能相中銀百分含量增加，膜層的方阻值逐漸減小，有一個臨界閾值，電阻溫度系數偏向正值。 -
When soil antecedent condition is dry and the initial rainfall intensity is high, peak surface runoff also considerably lag behind that of rainfall, because of the formation of temporary relative impermeable top layer ; b ) surface runoff is controlled primarily by infiltration - excess runoff mechanism under unsaturated condition ; the major fraction of surface runoff are dominated by saturated infiltration - excess runoff response, only a small fraction by return flow mechanism when soil is saturated ; c ) subsurface flow is dominated by saturated runoff mechanism, and the duration of subsurface post the rainfall end is dependent upon rather the soil properties than the rainfall characteristics ; d ) subsurface flow intensity in cultivated soil layer ( 0 ~ 20cm ) is high up to 35mm / h when rainfall intensity is up to 120mm / h, indicating the existing of macropores and pipe flow in cultivated layer
2 ）耕作制下紫色土的產流主要機制是： 1 ）當雨前土壤含水量未達到飽和狀態時，表面產流起始時間有明顯滯后現象，這與紫色土的快吸水性和較多非毛管孔隙密切相關；當雨前土壤較乾燥，降雨初期雨強較大時，易形成臨時相對不透水表層，表面產流峰也有明顯滯后現象。 2 ）表面徑流的產流方式主要是超滲產流，當土壤達到飽和狀態后，有四川大學博士學位論文小部分回歸流發生，但主要是飽和超滲產流發生，因為紫色土的相對不透水層和其它透水障礙層不明顯。 3 ）壤中流主要是飽和產流，與降雨過程有明顯的滯后，而且雨停后的壤中流產流歷時與降雨特徵無關。
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