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741.
Environmental Science and Pollution Research - The cytotoxicity of nanoparticles (NPs) and their properties are important issues in nanotechnology research. Particularly, NPs affect the metabolism...  相似文献   
742.
Political transitions often trigger substantial environmental changes. In particular, deforestation can result from the complex interplay among the components of a system—actors, institutions, and existing policies—adapting to new opportunities. A dynamic conceptual map of system components is particularly useful for systems in which multiple actors, each with different worldviews and motivations, may be simultaneously trying to alter different facets of the system, unaware of the impacts on other components. In Myanmar, a global biodiversity hotspot with the largest forest area in mainland Southeast Asia, ongoing political and economic reforms are likely to change the dynamics of deforestation drivers. A fundamental conceptual map of these dynamics is therefore a prerequisite for interventions to reduce deforestation. We used a system‐dynamics approach and causal‐network analysis to determine the proximate causes and underlying drivers of forest loss and degradation in Myanmar from 1995 to 2016 and to articulate the linkages among them. Proximate causes included infrastructure development, timber extraction, and agricultural expansion. These were stimulated primarily by formal agricultural, logging, mining, and hydropower concessions and economic investment and social issues relating to civil war and land tenure. Reform of land laws, the link between natural resource extraction and civil war, and the allocation of agricultural concessions will influence the extent of future forest loss and degradation in Myanmar. The causal‐network analysis identified priority areas for policy interventions, for example, creating a public registry of land‐concession holders to deter corruption in concession allocation. We recommend application of this analytical approach to other countries, particularly those undergoing political transition, to inform policy interventions to reduce forest loss and degradation.  相似文献   
743.
Design of landscape is the process of the arrangement of spatial features with the objective of sustaining ecosystem services, and maintaining ecological functionality to meet societal needs. Along a gradient of cultivation intensity, the functional quality of agricultural landscape was explored and the relationships between landscape metrics and functional quality were analyzed, in order to make effective recommendations for landscape design aimed at sustainable land use schemes. The functional quality of landscape was calculated using the InVest model for 20 farm landscapes (North-Eastern Italy) where biodiversity (plant taxa) and sensitivity to disturbance (hemeroby) were used as model inputs. Results highlighted the importance of specific habitat types such as meadows and woodlands rather than other habitats for improving the biodiversity of agricultural landscapes. A high proportion of these habitats enhanced the functional quality of the landscape when the habitats were organized in large and not isolated patches in heterogeneous landscapes.  相似文献   
744.
Landfilling is one of the most common ways of municipal solid waste disposal. Degradation of organic waste produces CH(4) and other landfill gases that significantly contribute to global warming. However, before entering the atmosphere, part of the produced CH(4) can be oxidised while passing through the landfill cover. In the present study, the oxidation rate of CH(4) was studied with various types of compost as possible landfill cover. The influence of incubation time, moisture content and temperature on the CH(4) oxidation capacity of different types of compost was examined. It was observed that the influence of moisture content and temperature on methane oxidation is time-dependent. Maximum oxidation rates were observed at moisture contents ranging from 45% to 110% (dry weight basis), while the optimum temperature ranged from 15 to 30 degrees C.  相似文献   
745.
Possible contaminants produced by the Petroleos Mexicanos (PEMEX) marine oil complex in the vicinity of the Cayo Arcas (Mexico) coral reef ecosystem were evaluated by analyzing sediments and sea water for hydrocarbons and metal elements. We found that the concentrations of aliphatic hydrocarbons in the sea water were generally low, with the highest values detected near the oil station; the concentration of polycyclic aromatic hydrocarbons (PAHs) was generally below the detection limit. The hydrocarbons found in the sediments seem to have a pyrogenic origin, and were probably produced by marine traffic in the study area. The total PAH concentration did not exceed the NOAA criteria, although levels of some individual PAHs did. The only metal detected in the sea water at high concentrations was nickel. The Ni/V ratio in the sediments indicates the contribution of crude oil to the system. The high content of Ni and Zn was attributed to the ballast waters from the oil tankers that load at the station's monobuoys. The presence of fine sediments that commonly originate from terrestrial ecosystems supported this assumption.  相似文献   
746.
简述了环境保护新特征的系统诊断,指出面对环境保护呈现的新特征,环境监测管理及建设存在环境监测的各项技术、标准、规范、管理措施滞后于社会经济基本现代化的发展要求,体制机制滞后于环境保护的发展要求,服务能力滞后于公共服务的需求,质量管理滞后于严格的环境管理需求等问题。提出,应从传统的环境监测向资源环境承载力监测预警转变,从条块管理向垂直管理的体制转变,从监测信息相对封闭向监测信息主动公开转变,由单纯依靠自身监测向依靠各部门和全社会监测转变,从污染物总量监测为主向污染物总量,环境质量监测并重转变,从实验室质控为主向全过程质控转变,从以生态,环境为核心的环境监测向以人为本的环境监测转变。  相似文献   
747.
In this paper, we use a stochastic integrated assessment model to evaluate the effects of uncertainty about future carbon taxes and the costs of low-carbon power technologies. We assess the implications of such ambiguity on the mitigation portfolio under a variety of assumptions and evaluate the role of emission performance standards and renewable portfolios in accompanying a market-based climate policy. Results suggest that climate policy and technology uncertainties are important with varying effects on all abatement options. The effect varies with the technology, the type of uncertainty, and the level of risk. We show that carbon price uncertainty does not substantially change the level of abatement, but it does have an influence on the mitigation portfolio, reducing in particular energy R&D investments in advanced technologies. When investment costs are uncertain, investments are discouraged, especially during the early stages, but the effect is mitigated for the technologies with technological learning prospects. Overall, these insights support some level of regulation to encourage investments in coal equipped with carbon capture and storage and clean energy R&D.  相似文献   
748.
The techniques of diffusive equilibrium in thin films (DET) and diffusive gradients in thin films (DGT) were used in the outer section of Songkhla Lake, Thailand in order to obtain high-resolution profiles of total dissolved and labile trace metals in the sediment pore water and investigate benthic fluxes. Six DET probes and six DGT probes were deployed at the mouths of the Phawong, Samrong and U-Taphao canals. A close correspondence could be observed between the high-resolution profiles of Fe and As, revealing a close link between the reductive remobilization of Fe oxides and the reduction of As(V). Co and Ni DGT profiles showed a close correspondence with Mn, but a narrow mobilization zone. Reductive mobilization of Mn oxides and associated metals and sulfide precipitation control the behaviour of these metals. The DGT profiles of Cu, Zn, Cd and Pb show surface maximum, probably linked to organic matter degradation. Important benthic fluxes, especially for As, were found at the mouths of the U-Taphao and Phawong canals.  相似文献   
749.
对空气-乙炔火焰原子吸收法测铬(Cr)时共存元素对其测定结果的干扰进行研究。结果表明,当ρ(共存元素)/ρ(Cr)100时,Mg、Co、Al、V、Ni、Fe、Na、Ca对Cr测定有影响,而K、Mn、Zn、Mo、Pb、Si、Cu均不影响Cr的测定;当ρ(共存元素)/ρ(Cr)为10和30时,加入1%HNO_3和2%NH_4Cl可消除干扰;当ρ(共存元素)/ρ(Cr)30时,加入5%HCl和超过1%的NH_4Cl可消除干扰;5%HCl作为介质消除Cr测定干扰的效果要优于1%HNO_3介质。  相似文献   
750.
In order to evaluate the impact of atmospheric pollutants emitted by the industrial settlement of Milazzo (Italy) on agriculture, sulphur dioxide and ozone levels in air were monitored and the data were used to estimate yield losses of the most widespread cultures. Trace element concentrations in crops and soils were also detected and metabolic profiles of soil microbial communities were considered. Vibrio fischeri test was used to appraise airborne pollutant ecotoxicity and epidemiological studies on causes of death distribution were carried out to characterize health state of people living in the area. All the sampling points were selected in farms on the basis of a theoretical meteo-diffusive model of industrial air pollutants. Experimental SO2 and O3 values mainly exceeded the threshold established by Italian and EU regulations to protect vegetation and they correspond to estimated significant crop losses. Conversely toxic element residues in soils and in agroalimentary products were generally lower than the fixed values. SO2 and O3 concentrations, toxic element contents and ecotoxicity levels of airborne pollutants were not related only to industrial site emissions, while the fluctuations on metabolic profiles of soil microbial communities seem to agree with the predicted deposition of xenobiotic compounds from the industrial plants. The epidemiological study evidenced a better health state of populations living in the investigated area than in the Messina province and the Sicily region but, inside the area, males living in the municipalities closest to the industrial settlement exhibited a worst health state than those in the very far ones.  相似文献   
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