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81.
An EPA program for monitoring ecological status and trends 总被引:1,自引:0,他引:1
Jay J. Messer Rick A. Linthurst W. Scott Overton 《Environmental monitoring and assessment》1991,17(1):67-78
Despite hundreds of millions of dollars spent annually in the United States on environmental monitoring, policy and decision makers seldom have ready access to monitoring data to aid in prioritizing reasearch and assessment efforts or to assess the extent to which current policies are meeting the desired objectives. EPA is currently conducting research to evaluate options for establishing an integrated, cooperative monitoring program, with participation by federal, state, and private entities, that could result in annual statistical reports and interpretive summaries on the status and trends in indicators of adverse disturbance and corresponding health of the nation's ecosystem on the regional and national scale.The research described in this article has not been subjected to U.S. Environmental Protection Agency review and therefore does not necessarily reflect the views of the Agency, and no official endorsement should be inferred. 相似文献
82.
Concentrations of Fe, Mn, Cu, dissolved organic matter (DOM), and pH were synthesized from 30 publications to determine the
factors regulating concentrations and behavior of metals in freshwater systems. Results from the review suggest that contrasting
watershed land use can directly (erosion and runoff) and indirectly (in-lake processes including metal–DOM–pH interactions)
affect the metal concentrations in freshwater systems. Among the watershed land uses considered here, concentrations of Fe,
Mn, and Cu were observed in the following order: arctic lakes < forested < agricultural < urbanized < mined. A drastic difference
in mean metal concentrations has been observed when undisturbed or low impact watersheds (arctic and forested) were changed
by agricultural, urban, and mining developments. Relationships between metal concentrations and pH revealed that metals precipitate
at high pH (pH > 5). Additionally, at pH < 5, metal concentrations were significantly correlated with DOM due to metal–DOM
complexation. High ratios of metal: DOM occur only at low DOM concentrations. Collectively, two general conclusions can be
drawn from this review. First, lakes, rivers, and streams with urbanized watersheds are the most susceptible to increased
concentrations of metals. Secondly, these results also suggest that regardless of high or low DOM in the water column, pH
would affect metal concentrations in freshwater systems. Nonetheless, free metal ions would be higher in freshwater systems
with acidic water and low DOM. 相似文献
83.
Susan Seacrest Robert Kuzelka Rick Leonard 《Journal of the American Water Resources Association》2000,36(2):253-263
ABSTRACT: Global climate change is examined from the perspective of its relevancy and urgency as a public policy issue. Interpreting from literature specific to investigations into public awareness and concern, climate change is seen as a legitimate though less than urgent issue. The literature reveals that the general public holds surprising misconceptions about the processes contributing to climate change, including failure to grasp the fundamental connection to CO2. General ambivalence is also suggested from the results of two surveys conducted by The Groundwater Foundation. They first asked participants in a recent Groundwater Guardian Conference to rate levels of discussion and concern for water resources implications in the participants' communities. A second survey polled national water resource organizations about the extent climate change has been a focus of their educational, investigative, or advocacy efforts. The paper concludes by describing basic barriers to stimulating public response to climate change, which education about the issue should address, and by offering a model to educate and involve citizens based on the Groundwater Guardian program developed by the The Groundwater Foundation. 相似文献
84.
Estimates of temporal trends in species’ occupancy are essential for conservation policy and planning, but limitations to the data and models often result in very high trend uncertainty. A critical source of uncertainty that degrades scientific credibility is that caused by disagreement among studies or models. Modelers are aware of this uncertainty but usually only partially estimate it and communicate it to decision makers. At the same time, there is growing awareness that full disclosure of uncertainty is critical for effective translation of science into policies and plans. But what are the most effective approaches to estimating uncertainty and communicating uncertainty to decision makers? We explored how alternative approaches to estimating and communicating uncertainty of species trends could affect decisions concerning conservation status of freshwater fishes. We used ensemble models to propagate trend uncertainty within and among models and communicated this uncertainty with categorical distributions of trend direction and magnitude. All approaches were designed to fit an established decision-making system used to assign species conservation status by the New Zealand government. Our results showed how approaches that failed to fully disclose uncertainty, while simplifying the information presented, could hamper species conservation or lead to ineffective decisions. We recommend an approach that was recently used effectively to communicate trend uncertainty to a panel responsible for setting the conservation status of New Zealand's freshwater fishes. 相似文献
85.
Rous Andrew M. Midwood Jonathon D. Gutowsky Lee F.G. Lapointe Nicolas W.R. Portiss Rick Sciscione Thomas Wells Mathew G. Doka Susan E. Cooke Steven J. 《Environmental management》2017,59(1):118-128
Environmental Management - Widespread human development has led to impairment of freshwater coastal wetlands and embayments, which provide critical and unique habitat for many freshwater fish... 相似文献
86.
Steinman AD Biddanda B Chu X Thompson K Rediske R 《Environmental monitoring and assessment》2007,134(1-3):177-189
Groundwater withdrawal has major economic, social, and environmental implications. In Michigan, recent legislative activity
has begun to address the issue of groundwater sustainability. However, more hydrologic data are needed to help inform policy
and legislation. A study was conducted in Mecosta County, Michigan to: (1) determine if a relationship could be established
between land use/land cover and groundwater quality; and (2) develop a conceptual model for the shallow groundwater system
of the study region. In general, groundwater quality was good, with below detection levels of E. coli, low total bacterial counts, and relatively low nutrient concentrations. No statistically significant associations were found
between the bacterial numbers and either land use or the physical/chemical attributes measured, which may be because the scale
of our spatial analysis was too coarse to detect patterns. Finer-scale, localized processes may have a greater influence on
microorganism growth and abundance than coarser-scale, regional processes in this area. Our groundwater analysis suggested
that shallow groundwater flow paths are generally consistent with regional surface water flow networks, and that shallow groundwater
levels in most of the region have fluctuated within 1–2 m over the past 30 years, with no obvious increasing or decreasing
trend. 相似文献
87.
88.
Adam Smale Silvia Bagdadli Rick Cotton Silvia Dello Russo Michael Dickmann Anders Dysvik Martina Gianecchini Robert Kae Mila Lazarova Astrid Reichel Paula Rozo Marijke Verbruggen 《组织行为杂志》2019,40(1):105-122
Although career proactivity has positive consequences for an individual's career success, studies mostly examine objective measures of success within single countries. This raises important questions about whether proactivity is equally beneficial for different aspects of subjective career success, and the extent to which these benefits extend across cultures. Drawing on Social Information Processing theory, we examined the relationship between proactive career behaviors and two aspects of subjective career success—financial success and work‐life balance—and the moderating role of national culture. We tested our hypotheses using multilevel analyses on a large‐scale sample of 11,892 employees from 22 countries covering nine of GLOBE's 10 cultural clusters. Although we found that proactive career behaviors were positively related to subjective financial success, this relationship was not significant for work‐life balance. Furthermore, career proactivity was relatively more important for subjective financial success in cultures with high in‐group collectivism, high power distance, and low uncertainty avoidance. For work‐life balance, career proactivity was relatively more important in cultures characterized by high in‐group collectivism and humane orientation. Our findings underline the need to treat subjective career success as a multidimensional construct and highlight the complex role of national culture in shaping the outcomes of career proactivity. 相似文献
89.
90.
Regression models for predicting total streamflow (TSF), baseflow (TBF), and storm runoff (TRO) are needed for water resource planning and management. This study used 54 streams with >20 years of streamflow gaging station records during the period October 1971 to September 2001 in Pennsylvania and partitioned TSF into TBF and TRO. TBF was considered a surrogate of groundwater recharge for basins. Regression models for predicting basin-wide TSF, TBF, and TRO were developed under three scenarios that varied in regression variables used for model development. Regression variables representing basin geomorphological, geological, soil, and climatic characteristics were estimated using geographic information systems. All regression models for TSF, TBF, and TRO had R(2) values >0.94 and reasonable prediction errors. The two best TSF models developed under scenarios 1 and 2 had similar absolute prediction errors. The same was true for the two best TBF models. Therefore, any one of the two best TSF and TBF models could be used for respective flow prediction depending on variable availability. The TRO model developed under scenario 1 had smaller absolute prediction errors than that developed under scenario 2. Simplified Area-alone models developed under scenario 3 might be used when variables for using best models are not available, but had lower R(2) values and higher or more variable prediction errors than the best models. 相似文献