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161.
一个适宜发展脐橙的区域 总被引:1,自引:0,他引:1
陈卓良 《长江流域资源与环境》1993,2(3):219-224
这是一篇关于三峡低山河谷脐橙引种栽培情况的调查报告。本文简略地介绍了三峡地区的地理和气候概况,报道该区域引种栽培试验的脐橙产量和品质的情况,也论证了脐橙对该区气候的适应性。通过论证说明了三峡低山河谷是一个很适宜商品性脐橙生产的区域。 相似文献
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Every year, nurseries waste about 40 t of residual biomass for each ha of potted plants cultivation. The European nursery sector deals with about 90,000 ha of cultivated land and 120,000 ha of nurseries, with a turnover of 19.8 billion Euros in 2011. In recent years, a number of Italian projects highlighted that GHG (greenhouse gas) emissions for the nursery sector range between 37 tCO2eq/ha/year and 45 tCO2eq/ha/year for potted plants, mainly due to the consumption of electric energy, plastics and peat. Moreover, other studies analyse the impacts associated to nurseries, recommending best practices for energy reductions and waste recycle or reuse. Therefore, the present work focused its attention to the possible environmental benefits associated to the reuse of residues (wood and substrate) of potted plants that are discarded from the nursery production chain. GHG emissions and fossil energy requirement were quantified by considering the CO2eq (CO2 equivalent) and the CER (cumulative energy requirement) respectively, in order to assess the environmental impacts of two different scenarios proposed for the materials recovery. Final results highlighted that the solutions which are able to recover the substrate and the wood allow impact reductions compared to landfill disposal. In particular, the scenario consisting in the immediate separation of the substrate from the root-plant system and the successive chipping of wood for energetic reuse, allows higher savings than those obtainable through shredding and subsequent wind separation. Moreover, for what concerns the CO2eq, an adequate use of the residual biomass make it possible to compensate the GHG emissions of the nurseries up to 15%. 相似文献
165.
王湃 《中国环境管理干部学院学报》2013,(2):81-84
职业是经济社会分层的表征,职业指导随着经济社会和职业的发展应运而生。从就业形势、社会对高校人才培养的要求及大学毕业生职业核心竞争力缺失等方面对高校就业工作现状进行了分析,提出将职业指导融入人才培养机制、目标、方法和内容等各个层面,实现大学生有序就业,完成高校办学与社会需求之间的有效对接。 相似文献
166.
The effects of agricultural improvement by cultivation, re-seeding, lime and fertiliser additions on the soil solution chemistry of acid podzolic soils have been investigated in a field experiment in a mid-Wales catchment. the treatment resulted in an increase in the pH, alkalinity and calcium content of soil waters from the surface, organic-rich horizon. in the year following treatment, soil waters in the mineral horizons became more acid and had higher aluminium concentrations than observed at the control site. This response is ascribed to soil water acidification resulting from increased nitrification rates following liming and cultivation. in subsequent years, soil water acidity in these lower horizons was neutralised by lime-rich water percolating from the surface. No changes in stream water acidity and calcium content were observed in the catchment containing the area of agriculturally improved soils. This suggests that the selective treatment of moorland catchments to improve agricultural productivity may not always be accompanied by amelioration of acid stream water. 相似文献
167.
活性污泥法快速培菌的探索与实践 总被引:2,自引:0,他引:2
本文介绍了一种快速培养,驯化活性微生物的方法,大大缩短了微物生长的停滞期,使活性污泥在培菌、驯化方面有很大的改进,做到节约时间、降低成本、减轻培菌期间的环境污染。使活性污泥法更加快速、高效。 相似文献
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报道了西双版纳纳板河流域自然保护区3个拉祜族村寨对土地和野生植物资源的利用现状,认为转变单纯采集为栽培种植价值大的野生植物是发展的根本出路。 相似文献
169.
张文丽 《防灾科技学院学报》2004,6(1):38-41
在制图教学中,利用CAD绘制二维工程图,建立三维立体虚拟模型,培养学生思维能力,使学生达到读图并绘制完整、正确、清晰的二维工程图的目的。 相似文献
170.
姜小文 《湖南环境生物职业技术学院学报》2002,8(2):98-104
综述了微繁、胚培养、胚乳培养、花药培养、原生质体培养与融合、转基因和基因克隆、分子标记等生物技术近年来在柑桔等南方果树上的应用. 相似文献