共查询到17条相似文献,搜索用时 0 毫秒
1.
Based on the total-factor energy efficiency framework,this paper calculates China’s industrial energy efficiency and CO2 emissions reduction potential from 2000 to 2009 by utilizing the directional distance function and data envelopment analysis.The empirical results show that:China’s industrial overall energy efficiency is relatively lower while the emis-sions reduction potential is relatively greater,given the optimum production frontier.Significant indus-trial disparities of energy efficiency and emissions reduction potential exist.Energy efficiency and emis-sions reduction potential significantly show different tendencies of industrial dynamic variation.This paper suggests the Chinese government impose differential carbon taxes,flexibly utilize carbon market mecha-nism,strengthen energy-saving technological R&D,promote the utilization of renewable energy,and strengthen environmental supervision and regulation,so as to improve China’s industrial energy efficiency and reduce CO2 emissions. 相似文献
2.
The HBV-N model was used for a scenario analysis of changes in nitrogen retention and transport caused by alterations of
wetness due to land drainage, lowering of lakes, building of dams and climatic variability in a river basin in south-central
Sweden (1885–1994). In general, dams were situated in locations more favourable for retention, compared to the lowered lakes.
Rather modest conversions of water bodies only changed nitrogen transport by about 3%. The 180-times-larger increase of (mainly)
tile-drained agricultural land had, according to simulations, increased the nitrogen transport by 17%, due to reduced retention.
However, compared to human-induced alteration of the landscape N retention, the choice of 10-year periods of climatological
data had the overriding effect on the calculated nitrogen transport. Weather-induced variations resulted in a 13% difference
in nitrogen retention between various 10-year periods. When the model was driven by climatological data from the driest 10-year
period (1905–1914), the estimated average annual load was only half of that obtained with climatological data from the wettest
10-year period (1975–1984).
Electronic Publication 相似文献
3.
The significant processes controlling the fate of particulates are convection an dispersion on one hand, and sedimentation on the other hand. Due to inteparticulated reactions, larger aggregates can be formed from smaller units thus changing the sedimentation characteristics. These phenomena are summarized in a mathematical model whereby hydrodynamic effects as well as the control mechanisms of the dissolved phase are included. A relationship was derived on the basis of energy considerations leading to the formulation of a critical sedimentation velocity of the suspensa, which determines the transport capacity of the flowing system. The sedimentation term is calculated from the above discussed transport capacity, hydro-dynamic parameters and suspending media properties. Aggregation effects are taken into account as an increase of sedimentation velocities of the particles. The equations are solved in a particular computational routine such that the horizontal distribution of suspended solids in a natural system can be describe as function of the above discussed phenomena. The model was tested with in situ-measurements. It was found that the observed processes are described satisfactorily by this model. 相似文献
4.
Variation in the relative spleen weight was studied in three small rodent species of two genera, Microtus and Myodes. Its range was found to reach 80?C94/%.. Regression equations for the upper and lower limits of normal spleen weight were calculated, and its values were shown to lie between 2.0 and 2.0?C5.0??. 相似文献
5.
He Jie Département d’économique GREDI Faculté d’administration Université de Sherbrooke boulevard de l’Univesité Sher-brooke QC JKR Canada 《中国人口.资源与环境(英文版)》2008,6(1):14-24
In this paper, we construct a model in which the impact of pollution on health is exerted through both direct and indirect channels. The indirect channel is captured by a production function in which the principal health-improving factor, income growth, can be realized only in the cost of pollution increase. This model is then tested by the aggregated chronicle disease data in over 78 Chinese counties. Our results show, after attaining the threshold of 8 μ g/m^2, continuous increase in industrial SO2 emission density will lead the ratio of population suffering chronicle diseases, among which respiratory diseases occupy a significant proportion, to rise. However, owing to technological progress in pollution control activities, the needed SO2 emission to produce one unit of GDP diminishes with time. Therefore, the negative effect from pollution augmentation on public health seems to be recompensed more and more by the positive effect of economic growth. 相似文献
6.
Bruno Fady Joan Cottrell Lennart Ackzell Ricardo Alía Bart Muys Arantxa Prada Santiago C. González-Martínez 《Regional Environmental Change》2016,16(4):927-939
The conservation and sustainable use of forests in the twenty-first century pose huge challenges for forest management and policy. Society demands that forests provide a wide range of ecosystem services, from timber products, raw materials and renewable energy to sociocultural amenities and habitats for nature conservation. Innovative management and policy approaches need to be developed to meet these often-conflicting demands in a context of environmental change of uncertain magnitude and scale. Genetic diversity is a key component of resilience and adaptability. Overall, forest tree populations are genetically very diverse, conferring them an enormous potential for genetic adaptation via the processes of gene flow and natural selection. Here, we review the main challenges facing our forests in the coming century and focus on how recent progress in genetics can contribute to the development of appropriate practical actions that forest managers and policy makers can adopt to promote forest resilience to climate change. Emerging knowledge will inform and clarify current controversies relating to the choice of appropriate genetic resources for planting, the effect of silvicultural systems and stand tending on adaptive potential and the best ways to harness genetic diversity in breeding and conservation programs. Gaps in our knowledge remain, and we identify where additional information is needed (e.g., the adaptive value of peripheral populations or the genetic determinism of key adaptive traits) and the types of studies that are required to provide this key understanding. 相似文献
7.
Simões Eliane de Sousa Junior Wilson C. de Freitas Débora M. Mills Morena Iwama Allan Y. Gonçalves Isabel Olivato Débora Fidelman Pedro 《Regional Environmental Change》2017,17(6):1739-1750
Regional Environmental Change - This paper examines barriers and opportunities for climate change adaptation in an urban coastal setting where adaptation is in its infancy. It draws on a diagnostic... 相似文献
8.
Beginning in 1960, the Spanish agricultural sector underwent an intensive process of development, resulting in important structural changes, not only in the sector itself, but also in the relationship of the agrarian system to natural resources. These changes were closely related to the growth of per capita income and Spain’s increasing integration into international markets. In the last five decades, the volume of Spanish agricultural trade has increased strongly, with a concomitant increase in the consumption of domestic water resources, requiring the construction of water infrastructure for irrigation. This paper examines the impact on water use in Spain during a period of economic modernization and trade liberalization. More specifically, we are interested in obtaining virtual water trade flow trends and identifying the major drivers responsible for these trajectories, via a decomposition analysis. Our results point to a large increase in virtual water exports and imports, primarily driven by the scale effect, that is, by the growing integration into international markets. The composition effect and changes in water intensity entailed a moderation in water consumption. 相似文献
9.
Emmanuel Yeboah-Assiamah Kobus Muller Kwame Ameyaw Domfeh 《Environment, Development and Sustainability》2018,20(5):2205-2224
Natural resource governance is underpinned by institutions which evolve ‘circumstantially’ over time. An attempt at understanding the contemporary institutions and governance structure of a resource requires an in-depth ethnographic enquiry. Adapting a four-phase institutional analysis framework, this study discusses the evolution and adaptation of wildlife governance structures and institutions using the unique experience of Boabeng–Fiema Monkey Sanctuary in Ghana. The study adopted a transdisciplinary research approach which was participatory and consultative. The key observations are that: wildlife institutions have gone through three main evolutionary phases, a pre-collaborative phase, which was exclusively underpinned by informal institutions; a critical juncture stage, where contextual challenges led to an adaptive response; the third and contemporary phase is a collaborative governance regime, where the erstwhile informal institutions have been complemented by formal state structures and institutions to synergistically enhance viability of the wildlife species. In spite of the problems posed to community members by the monkeys (wildlife), the study still observes a cordial human–wildlife relationship. Based on the study outcomes, we derive four key conclusions which have implications for institutionalism and natural resource governance. 相似文献
10.
In this study, we assess the risks of global warming on distributions of individual tree species in Switzerland. Applying
a spatially explicit model, tree occurrence is predicted as a function of high resolution and physiologically relevant biophysical
variables. The study shows that warming only slightly alters the overall abundance of tree species. However, the preferred
temperature regimes are unevenly distributed along an elevational gradient, and the sensitivity to temperature varies considerably
between the species. As a result, major reorganizations of forests in montane and subalpine belts are expected, i.e., a segregation
of the core distributions of Fagus sylvatica and Picea abies is observed. Tree distribution potentials near timberlines, however, remain roughly the same.
Electronic Publication 相似文献
11.
This paper describes the behaviour of 137Cs in Lago Maggiore and other pre-alpine lakes as a consequence of atmospheric nuclear weapons testing fallout and the fallout from the nuclear accident in Chernobyl. It presents data on the 137Cs distribution in tributaries, lake water, bottom sediments and reveals the role of 137Cs as a marker of the sedimentation processes. The run-off of 137Cs from the watershed to the lake is described with a simple compartment model. Measurements of the activity concentration of 137Cs in sediments are compared with the output of a model (diffusion–convection type) which describes the input of 137Cs into and its vertical distribution within the sediment. Varying sedimentation rates (0.05–0.90 g (cm2 y)−1) in Lago Maggiore are compared with data of other authors. Sedimentation rates and total distribution coefficients (of about 105 L kg−1) in Lago Maggiore are discussed and compared with those of Lago di Lugano, Lake Constance, and Lake Vorsee. 相似文献
12.
In the frame of the OFFICAIR project, indoor and outdoor PM2.5 samples were collected in office buildings across Europe in two sampling campaigns (summer and winter). The ability of the particles to deplete physiologically relevant antioxidants (ascorbic acid (AA), reduced glutathione (GSH)) in a synthetic respiratory tract lining fluid, i.e., oxidative potential (OP), was assessed. Furthermore, the link between particulate OP and the concentration of the PM constituents was investigated.The mean indoor PM2.5 mass concentration values were substantially lower than the related outdoor values with a mean indoor/outdoor PM2.5 mass concentration ratio of 0.62 and 0.61 for the summer and winter campaigns respectively. The OP of PM2.5 varied markedly across Europe with the highest outdoor OPAA m−3 and OPGSH m−3 (% antioxidant depletion/m3 air) values obtained for Hungary, while PM2.5 collected in Finland exhibited the lowest values. Seasonal variation could be observed for both indoor and outdoor OPAA m−3 and OPGSH m−3 with higher mean values during winter. The indoor/outdoor OPAA m−3 and OPGSH m−3 ratios were less than one with 4 and 17 exceptions out of the 40 cases respectively. These results indicate that indoor air is generally less oxidatively challenging than outdoors. Correlation analysis revealed that trace elements play an important role in determining OP, in particular, the Cu content. Indoor air chemistry might affect OP since weaker correlations were obtained for indoor PM2.5. Our findings also suggest that office workers may be exposed to health relevant PM constituents to a different extent within the same building. 相似文献
13.
The processes of soil and vegetation recovery after cessation of surface coal mining operations have been studied for the first time in the far north of Europe. Three stages of primary succession—from primitive algal groups to closed plant communities—have been identified, with the main role being played by soil algae at the zero stage, by herbs at the first stage, and by grasses at the second stage. A close relationship between the early stages in the development of phytocenoses and the stages of posttechnogenic soil formation is demonstrated. 相似文献
14.
Researching the dynamic distribution characteristics and trend evolution of agricultural carbon emissions is of considerable significance in formulating an effective agricultural carbon reduction policy. Based on measurement of agricultural carbon emissions of 31 provinces over the period 2002–2011, the study observed regional differences and the dynamic evolution of distribution of agricultural carbon emissions using agricultural carbon intensity as the indicator, accompanied by Gini coefficients and the kernel density estimation method. The results demonstrate first that agricultural carbon emissions for China show an obvious nonequilibrium nature in regard to spatial distribution. According to the differences in agricultural carbon emissions dynamic trends, we divided the 31 regions into four types – continuous decline, fluctuating decline, continuous increase, and fluctuating increase. Further, agricultural carbon emissions intensity showed a downward trend with significant differences in the research areas. Second, the gap in spatial distribution of national agricultural carbon emissions is gradually expanding based on the results calculated by Gini coefficient. From the perception of regional differences in agricultural carbon emissions, the eastern region showed an average level, the gap was more obvious in the central region, while western region showed a trend of fluctuating downward. Third, according to estimation by kernel density, the regional disparity in agricultural carbon emissions had a downward, but limited, trend. In regard to agricultural carbon emissions over the three areas, the regional gap not only tended to decrease but also showed a “four way” differentiation phenomenon in the eastern region. The difference in the central region difference was narrower. On the whole, the gap for the western region reduced steadily over a small range. 相似文献
15.
Howcroft CF Amorim MJ Gravato C Guilhermino L Soares AM 《Environment international》2009,35(2):318-324
Enchytraeids are important organisms of the soil biocenosis. They improve the soil pore structure and the degradation of organic matter. These organisms are used in standardized testing, using survival and reproduction (6 weeks) as endpoints. The use of biomarkers, linked to ecologically relevant alterations at higher levels of biological organization, is a promising tool for Environmental Risk Assessment. Here, enchytraeids were exposed for different time periods (two days and three weeks) to different soils (OECD artificial soil, different compositions in its organic matter, clay or pH value, and LUFA 2.2 natural soil) and different chemicals (Phenmedipham and copper). The main question addressed in the present study was if the effects of chemicals and different soil properties are preceded by alterations at the sub-cellular level, and if these endpoints may be used reliantly as faster screening tools for the assessment of different stress conditions in soils. The parameters measured in E. albidus whole body were: lipid peroxidation (LPO), total glutathione (TG), as well as the enzymatic activities of superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione S-transferase (GST). The results showed that biomarker responses in E. albidus were significantly affected by the soil type (GST, CAT, GPx, GR and LPO) and the duration of exposure in OECD artificial soil (GST, GPx, GR, CAT and LPO) but not in LUFA 2.2 natural soil. For the abiotic factors studied, after 2 days, low pH decreased significantly the TG levels and the activities of CAT and GR,and low OM also significantly decreased CAT and GR activities. After 3 weeks, differences in soil properties caused a decrease in GR and GPx activities, whereas increased GST activity was observed due to low organic matter and pH. Copper significantly increased the activities of CAT, GPx and GR, and decreased the activity of GST after 2 days as well as inscreasing LPO levels after 3 weeks. Phenmedipham increased LPO levels, associated with increased levels of TG as well as increased activities of CAT and GPx and decreased GST activity after 3 weeks exposure. This study shows that both abiotic and chemical stresses could be followed through biomarker analysis and that some of these determinations are potential endpoints in a quick soil contamination assessment procedure. 相似文献
16.
《International Journal of Sustainable Engineering》2013,6(3):154-172
Recovery of used products has become a field of rapidly growing importance in reverse supply chain management. Product recovery includes collection, inspection/separation, disassembly, reconditioning/reuse, remanufacturing, and recycling. In real time situations, the collection of end‐of‐life (EoL) products from the customer and their return to the manufacturer is tedious and time consuming. Reduced product life cycles have increased the rate of product returns and disposals. Owing to shortened product economic life cycles, the recovery of value from EoL products is becoming a necessity. Companies have realised the value that they could recover by remanufacturing or recycling EoL products. Researchers have developed various models for product recovery network design, optimal inventory, production planning and control, remanufacturing, recycling, disposal, etc. The main purpose of this paper is to review the literature on EoL product recovery and inventory management issues in reverse supply chains and to outline some future directions for research on these issues. 相似文献
17.
The objective of this study was to provide operational probability density functions (PDFs) for distribution coefficients (Kds) in freshwater, representing the partition of radionuclides between the particulate and the dissolved phases respectively. Accordingly, the Kd variability should be considered in uncertainty analysis of transport and risk assessment models. The construction of PDFs for 8 elements (Ag, Am, Co, Cs, I, Mn, Pu and Sr) was established according to the procedure already tested in Durrieu et al. [2006. A weighted bootstrap method for the determination of probability density functions of freshwater distribution coefficients (Kds) of Co, Cs, Sr and I radioisotopes. Chemosphere 65 (8), 1308–1320]: (i) construction of a comprehensive database where Kds values obtained under various environments and parametric conditions were collected; (ii) scoring procedure to account for the ‘quality’ of each datapoint (according to several criteria such as the presentation of data (e.g. raw data vs mean with or without replicates), contact time, pH, solid-to-liquid ratio, expert judgement) in the construction of the PDF; (iii) weighted bootstrapping procedure to build the PDFs, in order to give more importance to the most relevant datapoints. Two types of PDFs were constructed: (i) non-conditional, usable when no knowledge about the site of concern is available; (ii) conditional PDFs corresponding to a limited range of parameters such as pH or contact time; conditional PDFs can thus be used when some parametric information is known on the site under study. For 7 other radionuclides (Ba, Be, Ce, Ra, Ru, Sb and Th), a simplified procedure was adopted because of the scarcity of data: only non-conditional PDFs were built, without incorporating a scoring procedure. 相似文献