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961.
In this study, paddy fields in Jilin province which are flooded parcel of arable lands used for growing rice (Oryza sativa Linn.) were selected as the object. Long-term exploitation of paddy fields led to variations of soil organic carbon (SOC) and green house gases (GHGs) emissions which might contribute to global warming. In order to calculate the amount of global warming potentials (GWPs) of emissions from ricepaddies and find the correlations among rice yield, SOC storage and GWP, DeNitrification-DeComposition (DNDC) model was used to simulate SOC densities and fluxes of main GHGs emitted from paddy fields. After verification, simulation results were used to calculate SOC storages and 100-year GWPs from 1949 to 2009. Results indicated that SOC densities in depths of 0–10 cm, 10–20 cm and 20–30 cm all kept increasing. Average methane (CH4) and nitrous oxide (N2O) fluxes were 278.55 kg carbon (kgC) ha−1 a−1 and 2.22 kg nitrogen (kgN) ha−1 a−1. The SOC storage (0–30 cm) had increased from 3.96 × 109kgC in 1949 to 47.85 × 109kgC in 2009. In addition, GWP emission was increasing exponentially in the past 61 years, from 0.16 × 106 Mg carbon dioxide equivalents (CO2-equivalents) to 66.36 × 106 Mg CO2-equivalents. Both SOC storage and GWP presented obviously linear relation to rice yields. Overall, the research suggested that long-term rice yields could be used to estimate the SOC storage and GWP variations.  相似文献   
962.
介绍了液化烃的特性及主要火灾爆炸伤害模型,分析了诱发火灾爆炸的原因,并从本质化安全技术角度,提出了前期管理无缺陷的主要对策措施。  相似文献   
963.
自然环境谱编制方法研究   总被引:7,自引:6,他引:1  
针对装备(产品)在服役过程中所遭受的自然环境开展了自然环境谱编制方法研究,给出了自然环境谱的定义和编制程序,提出了盐雾和工业废气环境的判定标准,制定了适用于我国各种大气环境场地自然环境谱的编制方法,并举例编制了某地域的自然环境谱.  相似文献   
964.
以聚乙烯亚胺、巯基乙酸为原料,通过酰胺化反应合成了一种新型高分子重金属絮凝剂巯基乙酰聚乙烯亚胺(MAPEI),研究其处理含镉废水的性能,并对几个影响因素进行了考察。实验结果表明:①该絮凝剂对Cd2+有很好的捕集性能,最高去除率可达99.9%以上;②水中常见阳离子Na+、K+、Mg2+对Cd2+的去除起促进作用;③水中常见阴离子C l-、SO42-、NO3-对Cd2+的去除也起促进作用;④pH值在6.0至8.0范围内变化时,pH值越高去除Cd2+的效果越好;⑤Cd2+和致浊物质共存时,会相互促进彼此的去除。  相似文献   
965.
在结合实际确定陕西省二噁英的主要排放源及其排放因子基础上,采用国际通用的气体排放量计算法估算了陕西省2000年-2008年的二噁英年排放量,并就排放量的构成和变化趋势进行分析。结果显示:二噁英的年排放总量呈增长趋势,介于27.67 98.39 g TEQ之间;能源消耗产生的二噁英居于首位,其排放量约占总排放量的50%。工业燃料燃烧和工业生产过程所排放的二噁英占年排放量的60%以上,控制工业污染源的二噁英排放势在必行。  相似文献   
966.
Studies on mortality attributed to tropical cyclones often concern large-scale disasters. Attention is rarely paid to small-scale mortality over the long term. To understand the relationship between the environment and the behavior that contributes to mortality, this article uses a classification table to review the 1556 deaths attributed to tropical cyclones, named typhoons, in Taiwan during the period 2000–2014. The results demonstrate that the majority of outdoor deaths are associated with work-related activities, while most indoor deaths occur during non-work-related activities. Taking action, such as stopping the car on a bridge if the tail lights of a vehicle in front disappear, and not walking on the roadside when the road is flooded by muddy water, may help to reduce the likelihood of typhoon-attributed death. The findings also help to dispel four myths associated with typhoon-attributed mortality.  相似文献   
967.
为提高电网应急预案知识的检索效率以及电网事故的处置效率,提出电网应急预案知识图谱的构建方法。首先,以电网自然灾害和大面积停电事件应急预案为数据源,分析电网应急预案知识内容体系框架;其次,采用基于规则与基于深度学习的知识抽取方式对应急预案进行知识抽取,并基于Neo4j图数据库对电网应急预案知识进行存储和可视化展示;最后,以某市大面积停电事件应急响应为例,分析电网应急预案知识图谱在实际案例中的有效性。研究结果表明:所构建电网应急预案知识图谱可对电网突发事故进行辅助决策,从而缩短应急决策时间,提高电网事故的应急处置效率。  相似文献   
968.
Two representative zones in Chongming Dongtan which faced the Yangtze River and East China Sea respectively were selected to study the variability of soil organic carbon (SOC) reservation capability between coastal wetland and riverside wetland in the Chongming Dongtan wetland as well as its mechanism by analyzing soil characteristics and plant biomass. The results showed the SOC content of riverside wetland was only 48.61% (P = 0.000 < 0.05) that of coastal wetland. As the organic matter inputs from plant litter of the coastal wetland and riverside wetland were approximately the same, the higher soil microbial respiration (SMR) of riverside wetland led to its lower SOC reservation capability. In the riverside wetland, the high soil microbial biomass, higher proportion of β-Proteobacteria, which have strong carbon metabolism activity and the existence of some specific aerobic heterotrophic bacteria such as Bacilli and uncultured Lactococcus, were the important reasons for the higher SMR compared to the coastal wetland. There were additional differences in soil physical and chemical characteristics between the coastal wetland and riverside wetlands. Path analysis of predominant bacteria and microbial biomass showed that soil salinity influenced β-Proteobacteria and microbial biomass most negatively among these physical and chemical factors. Therefore the low salinity of the riverside area was suitable for the growth of microorganisms, especially β-Proteobacteria and some specific bacteria, which led to the high SMR and low SOC reservation capability when compared to the coastal area.  相似文献   
969.
Adsorption of the hydrophobic organic compounds (HOCs) trichloroethylene (TCE), 1,3-dichlorobenzene (DCB), 1,3-dinitrobenzene (DNB) and γ-hexachlorocyclohexane (HCH) on five different carbonaceous materials was compared. The adsorbents included three polymer-based activated carbons, one coal-based activated carbon (F400) and multiwalled carbon nanotubes (MWNT). The polymerbased activated carbons were prepared using KOH activation from waste polymers: polyvinyl chloride (PVC), polyethyleneterephthalate (PET) and tire rubber (TR). Compared with F400 and MWNT, activated carbons derived from PVC and PET exhibited fast adsorption kinetics and high adsorption capacity toward the HOCs, attributed to their extremely large hydrophobic surface area (2700 m2/g) and highly mesoporous structures. Adsorption of small-sized TCE was stronger on the tire-rubber-based carbon and F400 resulting from the pore-filling effect. In contrast, due to the molecular sieving effect, their adsorption on HCH was lower. MWNT exhibited the lowest adsorption capacity toward HOCs because of its low surface area and characteristic of aggregating in aqueous solution.  相似文献   
970.
汤成莉  常青  延卫 《环境工程》2012,(Z2):59-63
采用铁炭微电解技术为核心工艺的混凝-铁炭微电解-强化电解组合工艺对大蒜切片废水进行处理,主要研究了铁炭微电解的运行参数,包括曝气与否、废水pH值、反应时间、铁炭质量比、铁水质量比对COD去除效果的影响。结果表明:经过组合工艺处理后,废水刺鼻的气味完全消除,浊度去除率达100%,ρ(COD)值由13050mg/L降至878mg/L,去除率达93.3%,BOD5/COD(B/C)值由0.10提高到0.46,废水的可生化性显著提高。  相似文献   
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