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影响振动式挖掘机性能的主要参数 被引量:10
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作者 文学洙 《农机化研究》 北大核心 2012年第4期127-129,135,共3页
利用由振幅、振动频率和前进速度定义的参数λ,K和T,建立了对振动式挖掘机挖掘铲及振动筛上堆积的土壤平均高度、牵引力、驱动转矩和消耗动力的回归方程。从这些回归方程的决定系数可知,用参数T表示的回归方程的决定系数始终是次大。当... 利用由振幅、振动频率和前进速度定义的参数λ,K和T,建立了对振动式挖掘机挖掘铲及振动筛上堆积的土壤平均高度、牵引力、驱动转矩和消耗动力的回归方程。从这些回归方程的决定系数可知,用参数T表示的回归方程的决定系数始终是次大。当综合考虑上述情况时,用参数T表示的回归方程决定系数具有普遍性,根据土壤的分离能力,推荐T≥2.4。 展开更多
关键词 振动式挖掘机 土壤平均高度 牵引力 驱动转矩 消耗动力
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Nutrient uptake by mulberry and Chinese prickly ash associated with arbuscular mycorrhizal fungi
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作者 Hechun Piao Siliang Li Shijie Wang 《Acta Geochimica》 EI CAS CSCD 2016年第2期120-129,共10页
Understanding how nutrient absorption processes in plants are related to arbuscular mycorrhizal(AM)association is critical for predicting the effects of AM symbiosis on elemental cycling for plants. Both mulberry(Moru... Understanding how nutrient absorption processes in plants are related to arbuscular mycorrhizal(AM)association is critical for predicting the effects of AM symbiosis on elemental cycling for plants. Both mulberry(Morus alba) and Chinese prickly ash(Zanthoxylum bungeanum) are AM-associated plants, widely distributed in southwest China. It was hypothesized that if the nutrient absorption processes were efficiently associated with AM symbiosis in both mulberry and Chinese prickly ash, foliar nutrient concentrations—especially calcium(Ca)—would be primarily determined by the soil conditions in different regions. To investigate this, AM colonization levels of soils, nutrient levels in soils and leaves, and δ^(13)C values of leaves were analyzed for mulberry and Chinese prickly ash.In this study, spore density in soils with low p H was higher than that in soils with high p H. The average concentrations of sugar delivered to roots in both mulberry and Chinese prickly ash in soil with relatively low p H and soil extractable cations were higher than those in other areas.The values of foliar δ^(13)C in both mulberry and Chinese prickly ash in low soil-pH and soil extractable cations were lower than those in contrast areas, indicating that water availability was impacted by soil characteristics. The efficiency in AM-mediated processes might play an important role in translocation between soil nutrients and plant tissue.The results suggest uptake and translocation of nutrients,especially Ca, in AM-associated plants may be affected by an efficiency of AM-mediated processes. Since Sr does not appear to be similarly affected, expressing Ca and other nutrient concentrations relative to Sr could be used to evaluate whether the uptake and translocation of Ca and other nutrients are affected by AM-mediated processes. 展开更多
关键词 Arbuscular mycorrhizal fungi - Elementalratio Carbon isotopes MULBERRY Chinese prickly ash
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