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11.
This paper aims to identify the problems regarding the evaluation of ozone (and ozone-like) symptoms, by examining the results of the 4th UN/ECE ICP-Forests Intercalibration Course for the assessment of ozone-induced visible symptoms. Trees, shrubs and herbaceous species were evaluated in a tree nursery, at Lattecaldo (Switzerland) and under open field conditions at Moggio (Italy). The main findings were: (i) the most expert surveyors tended to be grouped in the same cluster and, during the field exercises, they tended to assess in a more conservative manner compared to the less trained participants; (ii) the agreement was greater in assessing the absence rather than the presence of symptoms; (iii) typical interveinal stippling on the upper leaf surface was more accurately evaluated than discoloration; (iv) uncertainties resulted mainly for species which showed greater variability in their symptom manifestation, and for certain herbaceous species.  相似文献   
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温室效应对我国长江中下游地区气候的影响--数值模拟   总被引:4,自引:0,他引:4  
利用RegCM2区域气候模式嵌套一个全球模式,进行了CO2加倍情况下对中国区域气候影响的数值试验,对长江中下游地区的情况进行了重点分析.结果表明,在CO2加倍的情况下,长江中下游地区的气温将明显升高,升高值一般在2.3~2.5℃以上,但低于全国平均值.同时,其大部分区域的降水也将增加,特别是在冬季和夏季,但年平均的增加率仅为7%,也低于全国平均值.温室效应会使该地区的日平均最高和最低气温升高,降水日数增多.夏季降水的增多可能会导致这一地区夏季更多的洪涝灾害.  相似文献   
14.
The bioaccumulation of two isomeric non-alternant non-priority polycyclic aromatic hydrocarbons (PAHs), namely cyclopenta[cd]pyrene and benzo[ghi]fluoranthene, was investigated in caged mussels (Mytilus galloprovincialis) exposed for 30 days in three sites of a coastal lagoon (Pialassa Baiona, Ravenna, Italy) contaminated by pyrogenic PAHs. The concentration of cyclopenta[cd]pyrene and benzo[ghi]fluoranthene increased from undetectable levels in reference mussels withdrawn from the Adriatic sea to 10-30 ng g(-1) dry weight in transplanted mussels. Other contaminants bioaccumulated by caged mussels included pyrene, fluoranthene and mercury. Whilst the isomer concentration ratio pyrene/fluoranthene in biota was comparable to that observed in sediments, the cyclopenta[cd]pyrene/benzo[ghi]fluoranthene ratio was much lower in mussels than in sediments. The lower sediment biota accumulation factor of cyclopenta[cd]pyrene with respect to that of benzo[ghi]fluoranthene was tentatively attributed to the greater biological activity of the former compound, which contains a reactive olefinic bond in the cyclopenta fused ring moiety. Given the higher mutagenic activity of cyclopenta[cd]pyrene with respect to other priority PAHs, its bioaccumulation from contaminated sediments may rise considerably the overall toxicity of PAH residues in exposed biota.  相似文献   
15.
Within the European intensive forest monitoring programme, the native vegetation on permanent Level II plots has been monitored for visible ozone injuries. The main purpose of the programme is to assess the potential risks for the forest vegetation and the natural ecosystems at the intensive monitoring plots. During the first years of the programme the surveys were qualitative, reporting only the number and the name of the symptomatic species in selected Light Exposed Sampling Site. In 2003 a new plot design was tested, based on the distribution of a number of miniplots along the edge of the forest, so as to obtain quantitative findings about the occurrence and distribution of the symptoms. The problems that still persist are related to: (i) the forest edge assessed for ozone symptoms may have a different floristic composition from the Level II plot itself; (ii) the anthropic pressure and the disturbances affecting the forest edge alters the floristic composition; (iii) the variability of the plant composition in the forest edge, which makes comparability difficult between different sites; and (iv) the evaluation of symptoms in several species that have not yet been experimentally tested. Further difficulties are due to the fact that symptoms observed in the field are often aspecific and cannot, therefore, be attributed solely to the phytotoxic action of ozone. To improve the effectiveness of the European programme, it is necessary: (i) to individualise and select common sensitive plant species for homogeneous ecological regions; (ii) to enhance experimental activities to test the sensitivity of a large number of plant species.  相似文献   
16.
In the industrial risk field, Hazmat Logistics research is growing as a sector of special relevance. The road transport of these substances is an activity with an elevated risk, involving drivers, logistics systems, industries, infrastructures, urban areas, etc.In the study of risk and safety of the logistics of hazardous materials there is a special relevance for new and complex elements, as human factors and mental models involved in managing critical incidents ‘‘on the road”. Moreover, the ‘‘emergency management training” of human resources in this field is often limited, and this represents another factor of vulnerability.In collaboration with SBG (one of the leading European Hazmat Logistics corporations), we developed a quali-quantitative study on cognitive representations and semantic perceptions of risk and emergency management procedures in tanker drivers. The main innovation of the study, with the direct involvement of the stakeholder and 47 drivers, is represented by the construction and use of ‘‘ad hoc” psychometrical and knowledge-elicitation, allowing a deeper analysis of workers’ mental models.The application of PCP tools of adapted RepGrid and Landfield Laddering Procedures allows to analyze some of the main qualitative structures of mental models held by drivers about Hazmat Logistics. Through the analysis of these mental models, it could become possible to set up efficient preventive actions for this type of industrial risk. We are going to discuss the consequences of these findings and methodological approaches for the industrial risk-and-safety field.  相似文献   
17.
137Cs and 60Co, two of the radionuclides more representative of discharges from nuclear facilities, are of interest for radiological protections because of their great mobility in biosphere and affinity with biological systems. The aim of the present work is the investigation of the possible influence of the vertical distribution of 137Cs and 60Co in soil upon their uptake by lettuce as function of plant's growth. An experiment ad hoc has been carried out in field conditions. The results show that (i) the transfer of 137Cs and 60Co from soil to lettuce is independent by their distribution in soil, (ii) the soil–plant transfer factors of 137Cs and 60Co show a similar trend vs. growth stage, (iii) the 40K transfer factor trend is different from those of anthropogenic radionuclides, and (iv) 137Cs and 60Co specific activities are about 1 Bq/kg, in the mature vegetable with soil activity from 9 to 21 kBq/m2.  相似文献   
18.
Visible ozone symptoms on leaves are expressions of physiological mechanisms to cope with oxidative stresses. Often, the symptoms consist of stippling, which corresponds to localized cell death (hypersensitive response, HR), separated from healthy cells by a layer of callose. The HR strategy tends to protect the healthy cells and in most cases the efficiency of chlorophyll to trap energy is not affected. In other cases, the efficiency of leaves to produce biomass declines and the plant loses its photosynthetic apparatus replacing it with a new, more efficient one. Another strategy consists of the production of pigments (anthocyanins), and leaves become reddish. In these cases, the most significant physiological manifestation consists of the enhanced dissipation of energy. These different behavior patterns are reflected in the initial events of photosynthetic activity, and can be monitored with techniques based on the direct fluorescence of chlorophyll a in photosystem II, applying the JIP-test.  相似文献   
19.
Ignition of natural gas (composed primarily of methane) is generally not considered to pose explosion hazards when in unconfined and low- or medium-congested areas, as most of the areas within LNG regasification facilities can typically be classified. However, as the degrees of confinement and/or congestion increase, the potential exists for the ignition of a methane cloud to result in damaging overpressures (as demonstrated by the recurring residential explosions due to natural gas leaks). Therefore, it is prudent to examine a proposed facility’s design to identify areas where vapor cloud explosions (VCEs) may cause damage, particularly if the damage may extend off site.An area of potential interest for VCEs is the dock, while an LNG carrier is being offloaded: the vessel hull provides one degree of confinement and the shoreline may provide another; some degree of congestion is provided by the dock and associated equipment.In this paper, the computational fluid dynamics (CFD) software FLACS is used to evaluate the consequences of the ignition of a flammable vapor cloud from an LNG spill during the LNG carrier offloading process. The simulations will demonstrate different approaches that can be taken to evaluate a vapor cloud explosion scenario in a partially confined and partially congested geometry.  相似文献   
20.
The exploration of the relationships between plant biotic dynamics and scale can reveal important information on ecosystem spatial organization by addressing preservation of information integrity in upscaling/downscaling procedures of land-surface parameterization for environmental modeling applications. Scale-dependent relations of vegetation dynamics are investigated in this study by using emergent biophysical characteristics obtained through a predictive multidimensional model of vegetation anomalies derived from remote-sensing observations. In particular, the analysis is focused on the spatial organization of some phenological parameters including deterministic variations (seasonal range, interannual variability, jump discontinuities) and stochastic components (plant memory, spatial correlations). The analysis is performed using MODIS-based Normalized Difference Vegetation Index (NDVI) 16-day composites for the period from March 2000 to December 2006 over Italy at different levels of spatial aggregation (1-8 km). Scale-dependences of the statistical moments of the phenological parameters are quantified through simple power laws for five distinct vegetated land covers. Results suggest that some biophysical characteristics, especially deterministic components, show no preferential spatial scale for important coverage. In particular, broad-leaved forests and natural grasslands are characterized by deterministic and low-distance spatial components well explained by scale relationships, which are modulated by possible spatiotemporal dynamics of climatic drivers. Agricultural lands show high scale-dependent relations on short-term biophysical memory sources and low-distance spatial components of phenology likely related to hierarchical interactions of anthropogenic and ecological processes; whereas mixed patterns of croplands and natural areas generally present no consistent scaling relations.  相似文献   
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