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171.
Nicolas Lamouroux Hervé Pella Ton H. Snelder Eric Sauquet Jérome Lejot Ude Shankar 《Journal of the American Water Resources Association》2014,50(1):1-13
Spatially comprehensive estimates of the physical characteristics of river segments over large areas are required in many large‐scale analyses of river systems and for the management of multiple basins. Remote sensing and modeling are often used to estimate river characteristics over large areas, but the uncertainties associated with these estimates and their dependence on the physical characteristics of the segments and their catchments are seldom quantified. Using test data with varying degrees of independence, we derived analytical models of the uncertainty associated with estimates of upstream catchment area (CA), segment slope, and mean annual discharge for all river segments of a digital representation of the hydrographic network of France. Although there were strong relationships between our test data and estimates at the scale of France, there were also large relative local uncertainties, which varied with the physical characteristics of the segments and their catchments. Discharge and CA were relatively uncertain where discharge was low and catchments were small. Discharge uncertainty also increased in catchments with large rainfall events and low minimum temperature. The uncertainty of segment slope was strongly related to segment length. Our uncertainty models were consistent across large regions of France, suggesting some degree of generality. Their analytical formulation should facilitate their use in large‐scale ecological studies and simulation models. 相似文献
172.
It is commonly put forward that effective uptake of research in policy or practice must be built upon a foundation of active knowledge exchange and stakeholder engagement during the research. However, what is often lacking is a systematic appreciation of the specific practices of knowledge exchange and their relative merits. The paper reports on a 2009 survey of 21 research projects within the UK Research Councils' Rural Economy and Land Use Programme regarding the involvement and perceived impact of over a thousand stakeholders in the research. The survey reveals that most stakeholders were involved as research subjects or as event participants. Large numbers were also engaged in the research process itself, including involvement in shaping the direction of research. Stakeholder engagement is perceived as bringing significant benefits to the process of knowledge production. A close relationship is found between mechanisms and approaches to knowledge exchange and the spread of benefits for researchers and stakeholders. Mutual benefits are gained from exchange of staff or where stakeholders are members of research advisory groups. Different stakeholder sectors are also associated with different patterns of engagement, which lead to contrasting impact patterns. Any efforts to alter knowledge exchange processes and outcomes must overcome these differing engagement tendencies. Overall, much greater attention should be given to early processes of knowledge exchange and stakeholder engagement within the lifetime of research projects. 相似文献
173.
Carbon dioxide is the major greenhouse gas responsible for global warming. Man-made CO2 emissions contribute approximately 63% of greenhouse gases and the cement industry is responsible for approximately 5% of CO2 emissions emitting nearly 900 kg of CO2 per 1000 kg of cement. CO2 from a cement plant was captured and purified to 98% using the monoethanolamine (MEA) based absorption process. The capture cost was $51 per tonne of CO2 captured, representing approximately 90% of total cost. Steam was the main operating cost representing 39% of the total capture cost. Switching from coal to natural gas reduces CO2 emissions by about 18%. At normal load, about 36 MW of waste heat is available for recovery to satisfy the parasitic heat requirements of MEA process; however, it is very difficult to recover. 相似文献
174.
Standard procedures for evaluating environmental impact involve comparison between before and after conditions or scenarios
or between treatment and control site pairs. In many cases, however, endogenous directional change (natural succession) is
expected to occur at a significant rate over the period of concern, particularly for manmade systems such as impoundments.
Static evaluations do not provide an adequate approach to such problems. A new evaluation frame is proposed. Nominal system
behavior over time is characterized by a stochastic envelope around a nominal trajectory. We show that both the state variance
and the sampling variance can change over time. In this context, environmental regulations can be framed as constraints, targets,
or conformance to ideal trajectories. Statistical tests for determining noncompliance are explored relative to process variance,
sample error, and sample size. Criteria are elucidated for choosing properties to monitor, sample size, and sampling interval. 相似文献
175.
The 2001 National Land Cover Database (NLCD) provides 30-m resolution estimates of percentage tree canopy and percentage impervious
cover for the conterminous United States. Previous estimates that compared NLCD tree canopy and impervious cover estimates
with photo-interpreted cover estimates within selected counties and places revealed that NLCD underestimates tree and impervious
cover. Based on these previous results, a wall-to-wall comprehensive national analysis was conducted to determine if and how
NLCD derived estimates of tree and impervious cover varies from photo-interpreted values across the conterminous United States.
Results of this analysis reveal that NLCD significantly underestimates tree cover in 64 of the 65 zones used to create the
NCLD cover maps, with a national average underestimation of 9.7% (standard error (SE) = 1.0%) and a maximum underestimation
of 28.4% in mapping zone 3. Impervious cover was also underestimated in 44 zones with an average underestimation of 1.4% (SE = 0.4%)
and a maximum underestimation of 5.7% in mapping zone 56. Understanding the degree of underestimation by mapping zone can
lead to better estimates of tree and impervious cover and a better understanding of the potential limitations associated with
NLCD cover estimates. 相似文献
176.
Kevin Shirley Eric Marland Jenna Cantrell Gregg Marland 《Mitigation and Adaptation Strategies for Global Change》2011,16(3):325-346
We recognize that carbon-containing products do not decay and release CO2 to the atmosphere instantaneously, but release that carbon over extended periods of time. For an initial production of a
stock of carbon-containing product, we can treat the release as a probability distribution covering the time over which that
release occurs. The probability distribution that models the carbon release predicts the amount of carbon that is released
as a function of time. The use of a probability distribution in accounting for the release of carbon to the atmosphere realizes
a fundamental shift from the idea that all carbon-containing products contribute to a single pool that decays in proportion
to the size of the stock. Viewing the release of carbon as a continuous probabilistic process introduces some theoretical
opportunities not available in the former paradigm by taking advantage of other fields where the use of probability distributions
has been prevalent for many decades. In particular, theories developed in the life insurance industry can guide the development
of pricing and payment structures for dealing with the costs associated with the oxidation and release of carbon. These costs
can arise from a number of proposed policies (cap and trade, carbon tax, social cost of carbon, etc), but in the end they
all result in there being a cost to releasing carbon to the atmosphere. If there is a cost to the emitter for CO2 emissions, payment for that cost will depend on both when the emissions actually occur and how payment is made. Here we outline
some of the pricing and payment structures that are possible which result from analogous theories in the life insurance industry.
This development not only provides useful constructs for valuing sequestered carbon, but highlights additional motivations
for employing a probability distribution approach to unify accounting methodologies for stocks of carbon containing products. 相似文献
177.
178.
Kenneth L. Cashdollar Eric S. Weiss Terry G. Montgomery John E. Going 《Journal of Loss Prevention in the Process Industries》2007,20(4-6):607-615
The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) and the Mine Safety and Health Administration (MSHA) conducted joint research on dust explosions by studying post-explosion dust samples. The samples were collected after full-scale explosions at the PRL Lake Lynn Experimental Mine (LLEM), and after laboratory explosions in the PRL 20-L chamber and the Fike 1 m3 chamber. The dusts studied included both high- and low-volatile bituminous coals. Low temperature ashing for 24 h at 515 °C was used to measure the incombustible content of the dust before and after the explosions. The data showed that the post-explosion incombustible content was always as high as, or higher than the initial incombustible content. The MSHA alcohol coking test was used to determine the amount of coked dust in the post-explosion samples. The results showed that almost all coal dust that was suspended within the explosion flame produced significant amounts of coke. Measurements of floor dust concentrations after LLEM explosions were compared with the initial dust loadings to determine the transport distance of dust during an explosion. All these data will be useful in future forensic investigations of accidental dust explosions in coal mines, or elsewhere. 相似文献
179.
Solid waste management (SWM) facilities are crucial for environmental management and public health in urban regions. Due to the waste management hierarchy, one of the greatest challenges that organizations face today is to figure out how to diversify the treatment options, increase the reliability of infrastructure systems, and leverage the redistribution of waste streams among incineration, compost, recycling, and other facilities to their competitive advantage region wide. Systems analysis plays an important role for regionalization assessment of integrated SWM systems, leading to provide decision makers with break-through insights and risk-informed strategies. This paper aims to apply a minimax regret optimization analysis for improving SWM strategies in the Lower Rio Grande Valley (LRGV), an economically fast growing region in the US. Based on different environmental, economic, legal, and social conditions, event-based simulation in the first stage links estimated waste streams in major cities in LRGV with possible solid waste management alternatives. The optimization analysis in the second stage emphasizes the trade-offs and associated regret evaluation with respect to predetermined scenarios. Such optimization analyses with multiple criteria have featured notable successes, either by public or private efforts, in diverting recyclables, green waste, yard waste, and biosolids from the municipal solid waste streams to upcoming waste-to-energy, composting, and recycling facilities. Model outputs may link prescribed regret scenarios in decision making with various scales of regionalization policies. The insights drawn from the system-oriented, forward-looking, and preventative study can eventually help decision-makers and stakeholders gain a scientific understanding of the consequences of short-term and long-term decisions relating to sustainable SWM in the fast-growing US-Mexico borderland. 相似文献
180.
Validation of the propensity for angry driving scale 总被引:1,自引:0,他引:1
Problem: This study examined the validity of the Propensity for Angry Driving Scale (PADS; DePasquale, J. P., Geller, E. S., Clarke, S. W., and Littleton, L. C. (2001). Measuring road rage: Development of the Propensity for Angry Driving Scale. Journal of Safety Research, 32, 1–16) in predicting aggressive driving. Method: The PADS and the Driving Anger Scale (DAS; Deffenbacher, J. L., Oetting, E. R., and Lynch, R. S. (1994). Development of a driving anger scale. Psychological reports, 74, 83–91.) were administered to 232 college student volunteers with measures of aggressive and risky driving. Results: Convergent and discriminant validity of the PADS were supported through relationships among measures of similar constructs. The PADS significantly (p<.05) predicted moving tickets, minor accidents, aggressive driving, risky driving, and maladaptive driving anger expression, above and beyond gender, miles driven per week, and trait anger. Discussion: Findings suggest that the PADS is a useful predictor of aggressive driving and has some advantages over the DAS. Impact on Industry: The PADS is an effective predictor of aggressive driving that complements established measures like the DAS and provides researchers with another valuable tool for the assessment of aggressive driving. 相似文献