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Elisa Pellegrino Claudia Di Bene Cristiano Tozzini Enrico Bonari 《Agriculture, ecosystems & environment》2011,140(1-2):245-254
Bioenergy crops play an ecologically and economically fundamental role as an alternative to agri-food productions and as renewable energy sources. Little attention has been focused on soil quality following conversion of agricultural lands to biomass crops. Here, we assessed the impact of a 10-year-old short-rotation coppice (SRC) poplar stand on the main soil chemical parameters, microbial biomass carbon, soil respiration, and arbuscular mycorrhizal fungi (AMF), compared with intensive agricultural and uncultivated systems. Three different harvest frequencies of poplar SRC (annual T1, biannual T2 and triennial T3 cutting cycles) were evaluated. Multivariate analysis showed that poplar SRC improved soil quality compared with intensive agricultural and uncultivated systems. T1 and T2 positively affected AMF inoculum potential and root colonisation of a co-occurring plant species, while T3 improved the majority of soil chemical and biochemical parameters. Moreover, three different AMF morphospecies belonging to the genera Glomus and Scutellospora were found in poplar SRC, while morphospecies belonging exclusively to genera Glomus were recorded in intensive agricultural and uncultivated systems. Such aspects have agro-ecological implications, since the positive changes of soil nutrient availability and carbon content together with a high abundance and diversity of soil biota show clear soil sustainability of poplar SRC. 相似文献
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对流化床厌氧反应器的流化及反应特性进行研究,结果显示:床层实际初始流化流速umf为0.138~0.154cm/min,与理论计算值0.143 cm/min一致;在一定范围内,流速增大有利于反应量的提高,当流速为0.414 cm/min时,单位时间内的反应量达到最大,其值为4.66 mg/(L·min);适当提高流速有利... 相似文献
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目的:调查催化剂企业粉尘危害情况,分析对作业人员健康影响.方法:对现场粉尘浓度进行检测,调查企业粉尘防护情况.结果:粉尘检测结果均符合国家标准限值要求.结论:某催化剂企业粉尘职业危害防控情况较好,粉尘检查结果合格率较高. 相似文献
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Seasonal variations and size distributions of water-soluble ions in atmospheric aerosols in Beijing, 2012 总被引:5,自引:0,他引:5
Yongjie Yang Rui Zhou Jianjun Wu Yue Yu Zhiqiang M Lejian Zhang Yi''an Di 《环境科学学报(英文版)》2015,27(8):197-205
The characteristics of water-soluble ions in airborne particulate matter in Beijing were investigated using ion chromatography. The results showed that the total concentrations of ions were 83.7 ± 48.9 μg/m3 in spring, 54.0 ± 17.0 μg/m3 in summer, 54.1 ± 42.9 μg/m3 in autumn, and 88.8 ± 47.7 μg/m3 in winter, respectively. Furthermore, out of all the ions, NO3−, SO42 − and NH4+ accounted for 81.2% in spring, 78.5% in summer, 74.6% in autumn, and 76.3% in winter. Mg2 + and Ca2 + were mainly associated with coarse particles, with a peak that ranged from 5.8 to 9.0 μm. Na+, NH4+ and Cl− had a multi-mode distribution with peaks that ranged from 0.43 to 1.1 μm and 4.7 to 9.0 μm. K+, NO3−, and SO42 − were mainly associated with fine particles, with a peak that ranged from 0.65 to 2.1 μm. The concentrations of Na+, K+, Mg2 +, Ca2 +, NH4+, Cl−, NO3− and SO42 − were 2.69, 2.32, 1.01, 4.84, 16.9, 11.8, 42.0, and 44.1 μg/m3 in particulate matter (PM) on foggy days, respectively, which were 1.4 to 7.3 times higher than those on clear days. The concentrations of these ions were 2.40, 1.66, 0.92, 4.95, 17.5, 7.00, 32.6, and 34.7 μg/m3 in PM on hazy days, respectively, which were 1.2–5.7 times higher than those on clear days. 相似文献
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为探究山区河道型水库中,滑坡涌浪产生的冲击波对重力坝漫坝的影响,运用三维物理模型试验方法,探究近坝库区滑坡涌浪冲击波到达坝前时,坝前首浪最大振幅与涌浪漫坝体积的关系。结果显示,坝前首浪振幅沿坝体两岸向中间减小,坝段中心容易出现最小值;漫坝体积随首浪振幅的增加而增大。研究结果表明:坝前首浪最大振幅与涌浪漫坝体积两者呈正相关关系,漫坝体积受滑坡体角度与滑坡体积影响显著,进而构建漫坝体积计算方法。研究结果能够为大坝安全评估提供一定参考依据。 相似文献