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81.
广西罗城马尾松、杉木、桉树人工林碳储量及其动态变化 总被引:1,自引:0,他引:1
对广西罗城仫佬族自治县杉木(Cunninghamia lanceolata)、马尾松(Pinus massoniana)桉树(Eucalyptus grandis x E.urophylla)人工林生态系统碳含量、碳储量进行了研究,结果表明:不同发育阶段马尾松、杉木、桉树人工林林下植被含碳率变化幅度为37.96%~49.03%,枯落物含碳率为41.8%~49.6%之间,马尾松幼龄林林下植被含碳率最高,2年生桉树林枯落物含碳率最小。0~60 cm土层含碳率变化幅度为0.45%~2.17%,0~20 cm土层含碳率表现为杉木〉马尾松〉桉树。马尾松、杉木、桉树人工林生态系统碳储量分别为135.61、144.30、87.54 t.hm-2,马尾松和桉树人工林生态系统碳储量均表现为随林龄的增加而增加,马尾松幼龄和近熟林碳储量分别高于杉木,杉木中龄林碳储量高于马尾松中龄林。马尾松、杉木、桉树人工林乔木碳储量分别占其总碳储量的43.03%、34.44%、22.92%。马尾松、杉木、桉树人工林下植被碳储量表现为桉树(2.54 t.hm-2)〉杉木(1.91 t.hm-2)〉马尾松(0.89 t.hm-2)。马尾松、杉木、桉树人工林枯落物碳储量分别占其总碳储量的1.64%、4.56%、1.95%。马尾松、杉木、桉树人工林土壤碳储量分别为74.13、86.48、62.95 t.hm-2,杉木人工林土壤碳储量最高,桉树最小,0~20 cm土层碳储量成为土壤的主体,马尾松0~20 cm土层碳储量占其土壤总碳储量的47.03%,杉木占51.67%,桉树为42.58%。乔木和土壤碳储量成为整个森林生态系统的主要的碳储存库。 相似文献
82.
大型石油储罐消防设计研究 总被引:1,自引:1,他引:0
根据我国大型储罐设置的特点,分析了大型石油储罐在储存、转运过程中潜在的火灾危险。通过对千例石油火灾案例统计分析,获得了石油储罐发生火灾的主要原因。在此基础上,从石油储罐工艺设计、布局、防火和灭火等角度出发,分析大型石油储罐常用的类型、材料和防腐处理技术;研究储罐的布置间距;总结大型储罐消防设计中采用的防、灭火技术措施。论文研究的成果,可供实践工程参考。 相似文献
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轻柴油储罐火灾过程及安全性评价 总被引:4,自引:1,他引:3
从 2 0 0 2年 1月 1日起我国实施新的“轻柴油”产品标准 ,新标准将轻柴油的闪点指标由原来的≥ 65℃改为≥ 5 5℃ ,由此导致轻柴油的火灾危险类别发生变化 ,并进而引发原有轻柴油储罐能否安全储存新标准轻柴油的问题。笔者利用化学流体力学模型和挪威船级社 (DNV)的SAFETI风险评估软件对 65℃闪点和 5 5℃闪点轻柴油的储存火灾危害性进行了评估 ,取得了轻柴油火灾中危害程度的计算机模拟结果 相似文献
85.
Scott D. Wilson 《Environmental management》1988,12(3):397-403
The effect of various frequencies and seasons of military tank traffic on native mixed-grass prairie was examined in a randomized and replicated field experiment. Vegetation (in 10×10 m plots) was subjected to tank traffic at the following rates: (a) one pass per day of training from May until August; (b) one pass per day in May and June; (c) one pass per day in July and August; (d) one pass every three weeks from May until August; (e) zero (control). Species composition and the amount of bare ground were found to vary significantly with traffic frequency. Plant species alien to North America invaded plots subjected to spring driving. Regression analysis showed spring driving to produce more bare ground than summer driving. The regression models suggested that much higher intensities of training could be conducted without damage if spring driving were avoided. Regression models were also used to estimate the frequency of traffic associated with a significant change in species composition, where species composition was expressed as the ratio ofBouteloua gracilis toStipa spartea, an indicator of disturbance-induced change in prairie vegetation. This relationship predicted the capacity of the vegetation of a training area of any given width to support tank traffic without changing species composition. The predictive ability of the model was tested by comparing predicted traffic capacities with the amount of traffic actually applied to two training areas in 1986. Where traffic capacity was exceeded, the model successfully predicted a significantly higher frequency of bare ground and ratio ofBouteloua gracilis toStipa spartea. 相似文献
86.
Storage was used as a pretreatment to enhance the methanization performance of mesophilic anaerobic digestion of food waste. Food wastes were separately stored for 0, 1,2, 3, 4, 5, 7, and 12 days, and then fed into a methanogenic reactor for a biochemical methane potential(BMP) test lasting up to 60 days. Relative to the methane production of food waste stored for 0–1 day(285–308 m L/g-added volatile solids(VSadded)), that after2–4 days and after 5–12 days of storage increased to 418–530 and 618–696 m L/g-VSadded,respectively. The efficiency of hydrolysis and acidification of pre-stored food waste in the methanization reactors increased with storage time. The characteristics of stored waste suggest that methane production was not correlated with the total hydrolysis efficiency of organics in pre-stored food waste but was positively correlated with the storage time and acidification level of the waste. From the results, we recommend 5–7 days of storage of food waste in anaerobic digestion treatment plants. 相似文献
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油品储运中的环境保护 总被引:3,自引:0,他引:3
杨峋 《石油化工环境保护》2006,29(1):56-58
油品储运中的环境保护是设计工作中应重视的问题,本文从油气储运过程中的污染源、所产生的危害以及设计中应采取的环保对策等三个方面进行阐述。 相似文献
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