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61.
We review the current state of knowledge about urban ecosystem services in New York City (NYC) and how these services are regulated, planned for, and managed. Focusing on ecosystem services that have presented challenges in NYC—including stormwater quality enhancement and flood control, drinking water quality, food provisioning and recreation—we find that mismatches between the scale of production and scale of management occur where service provision is insufficient. Adequate production of locally produced services and services which are more accessible when produced locally is challenging in the context of dense urban development that is characteristic of NYC. Management approaches are needed to address scale mismatches in the production and consumption of ecosystem services. By coordinating along multiple scales of management and promoting best management practices, urban leaders have an opportunity to ensure that nature and ecosystem processes are protected in cities to support the delivery of fundamental urban ecosystem services.  相似文献   
62.
The qualified finished water from water treatment plants (WTPs) may become discolored and deteriorated during transportation in drinking water distribution systems (DWDSs), which affected tap water quality seriously. This water stability problem often occurs due to pipe corrosion and the destabilization of corrosion scales. This paper provides a comprehensive review of pipe corrosion in DWDSs, including corrosion process, corrosion scale formation, influencing factors and monitoring technologies utilized in DWDSs. In terms of corrosion process, corrosion occurrence, development mechanisms, currently applied assays, and indices used to determine the corrosion possibility are summarized, as well as the chemical and bacterial influences. In terms of scale formation, explanations for the nature of corrosion and scale formation mechanisms are discussed and its typical multilayered structure is illustrated. Furthermore, the influences of water quality and microbial activity on scale transformation are comprehensively discussed. Corrosion-related bacteria at the genus level and their associated corrosion mechanism are also summarized. This review helps deepen the current understanding of pipe corrosion and scale formation in DWDSs, providing guidance for water supply utilities to ensure effective measures to maintain water quality stability and guarantee drinking water safety.  相似文献   
63.
An important factor that limits children's autonomy outdoors is parental perception of social danger and traffic danger. To obtain quantitative instruments for these dimensions, this work aimed to explore the validity and reliability of three scales. Two of them describe, respectively, problematic aspects of the area of residence linked to traffic and situations of social degradation that could constitute risk factors for the child's psychological and physical safety (Traffic Danger Perception Scale, Social Danger Perception Scale). The third scale investigates parental perception of the positive potentiality of outdoor autonomy for children's maturation and growth. Interviews were conducted with 377 mothers of children between 8 and 10 years of age residing in six different areas in Italy. The results indicated weak reliability of the Traffic Danger Perception Scale, which requires further investigation, and they confirmed the reliability and the construct validity of the Social Danger Perception Scale and the Perception of Positive Potentiality of Outdoor Autonomy for Children Scale. The perception of social danger was higher in mothers who live in larger urban contexts and who have more personal fear of crime and a lower sense of community. The positive perception of children's autonomy of movement was higher among mothers who live in greener areas, who have a greater sense of community and who have more neighbourhood relations.  相似文献   
64.
This short note discusses methodological obstacles to the collection of microeconomic data in artisanal and small-scale mining communities. International donor organizations are supporting policy efforts that enhance the contribution to poverty alleviation of this mining subsector. The design and evaluation of such policy interventions require data on income, expenditure, investment, and savings in mining households and communities. These data are difficult to come by. Incomes are variable; migrants may work far from home; miners often work informally and sometimes illegally; mining populations and communities are heterogeneous and transient; and miners have many reasons to distort information. Legalization and organization of miners in cooperatives would facilitate documentation and research. These processes, however, are beyond the control of the typical policy consultant or donor organization. On their part, these parties can adopt an alternative model of research. This model involves the community in project development, data collection, and monitoring. It emphasizes continuity, cultural diversity, trust building and learning. The data thus collected should provide a firm basis for programmes that promote more sustainable livelihoods in artisanal and small-scale mining communities.  相似文献   
65.
The literature on trade openness, economic development, and the environment is largely inconclusive about the environmental consequences of trade. This study treats trade and income as endogenous and estimates the overall impact of trade openness on environmental quality using the instrumental variables technique. We find that whether or not trade has a beneficial effect on the environment varies depending on the pollutant and the country. Trade is found to benefit the environment in OECD countries. It has detrimental effects, however, on sulfur dioxide (SO2) and carbon dioxide (CO2) emissions in non-OECD countries, although it does lower biochemical oxygen demand (BOD) emissions in these countries. We also find the impact is large in the long term, after the dynamic adjustment process, although it is small in the short term.  相似文献   
66.
Matrix diffusion is an important mechanism for solute transport in fractured rock. We recently conducted a literature survey on the effective matrix diffusion coefficient, Dme, a key parameter for describing matrix diffusion processes at the field scale. Forty field tracer tests at 15 fractured geologic sites were surveyed and selected for the study, based on data availability and quality. Field-scale Dme values were calculated, either directly using data reported in the literature, or by reanalyzing the corresponding field tracer tests. The reanalysis was conducted for the selected tracer tests using analytic or semi-analytic solutions for tracer transport in linear, radial, or interwell flow fields. Surveyed data show that the scale factor of the effective matrix diffusion coefficient (defined as the ratio of Dme to the lab-scale matrix diffusion coefficient, Dm, of the same tracer) is generally larger than one, indicating that the effective matrix diffusion coefficient in the field is comparatively larger than the matrix diffusion coefficient at the rock-core scale. This larger value can be attributed to the many mass-transfer processes at different scales in naturally heterogeneous, fractured rock systems.Furthermore, we observed a moderate, on average trend toward systematic increase in the scale factor with observation scale. This trend suggests that the effective matrix diffusion coefficient is likely to be statistically scale-dependent. The scale-factor value ranges from 0.5 to 884 for observation scales from 5 to 2000 m. At a given scale, the scale factor varies by two orders of magnitude, reflecting the influence of differing degrees of fractured rock heterogeneity at different geologic sites. In addition, the surveyed data indicate that field-scale longitudinal dispersivity generally increases with observation scale, which is consistent with previous studies. The scale-dependent field-scale matrix diffusion coefficient (and dispersivity) may have significant implications for assessing long-term, large-scale radionuclide and contaminant transport events in fractured rock, both for nuclear waste disposal and contaminant remediation.  相似文献   
67.
This paper describes an experimental study of 2300 L pressure vessels exposed to remote fire heating by a natural gas fuelled wall fire simulator. The tanks were filled to 15% capacity with commercial liquid propane. The flame intensity and distance were varied to study the effect of different heating levels on the tank and its lading.The fire simulator is first characterized with tests including fire thermocouples, radiative flux meters and thermal imaging. With the appropriate positioning of a target tank it is possible to get very realistic fire heat fluxes at the tank surface.Three tests were conducted with the 2300 L tanks filled to 15% capacity with propane. The tanks were positioned at three different distances from the wall fire resulting in measured average peak heat flux at the tank surfaces ranging between 24 and 43 kW m?2. The data shows rapid rise in vapour space wall temperatures, significant temperature stratification in the vapour space, and moderate rate of pressure rise. These results provide excellent data for the validation of computer models used to predict the response of pressure vessels exposed to moderate heating from a remote fire.  相似文献   
68.
The objective was to explore the relationship between person-based variables and work-related variables of presenteeism in four different private sector workplaces. Employees (N=413) filled in a questionnaire related to demographic and socio-economic characteristics, social networks, work-related factors, lifestyle factors and state of health. Presenteeism was assessed using the Stanford Presenteeism Scale 6 (SPS-6). The majority of respondents were male (77.2%), and mean age was 34.7±8.1 years. The prevalence of chronic conditions was 15.9%. The mean score for the SPS-6 was 19.9 (SD, 3.3). The female score was higher than the male score on the SPS-6 in this study. Total score was higher among workers who reported working at high speed. SPS-6 score was higher among individuals with a chronic health problem. Understanding of the workplace and personal factors related to presenteeism may support the health and well-being of workers.  相似文献   
69.
Critical loads have been used to develop international agreements on acidifying air pollution abatement, and within the UK and other countries, to develop national policies for pollution abatement. The Environment Agency (England and Wales) has regulatory obligations to protect sites of high conservation value from the threat of acidification, and hence requires a practical methodology for acidification assessments at the site-specific scale. The Environment Agency has therefore posed the question: Are the national critical load exceedance models sufficiently robust to form the basis for methods to assess harm to individual sites or are they only useful for national policy development? In order to provide one measure of the appropriateness of applying the models at the site-specific scale we incorporated estimates of uncertainty in both national and site-specific data into the calculation of critical load exceedance for individual sites. The exceedance calculations use data from a wide range of sources and the accuracy of the exceedance will be influenced by the accuracy of the input data sets. Using Monte Carlo methods to incorporate the uncertainty in the input data sets into the calculation a distribution of critical load exceedance values is generated rather than a single point estimate. This paper compares uncertainty analyses for coniferous forested sites in England and Wales using both national scale and site-specific data sets and uncertainty ranges.  相似文献   
70.
Integrating mitigation and adaptation (M&A) is a practical reality for climate change response policy, despite a range of conceptual and methodological challenges. Based on the papers in this special issue, some preliminary findings about appropriate integrated portfolios are offered, along with several implications for climate policy.  相似文献   
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