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501.
Evaluation of PPCPs removal in a combined anaerobic digester-constructed wetland pilot plant treating urban wastewater 总被引:3,自引:0,他引:3
The removal efficiency of 16 pharmaceuticals and personal care products (PPCPs) from urban wastewater (dissolved and particulate phases) was evaluated for the first time in a hybrid pilot plant consisting of an upflow anaerobic sludge blanket reactor followed by two sequentially connected horizontal flow constructed wetlands: a surface flow wetland (SF CW) and a subsurface flow wetland (SSF CW). Whereas the PPCP removal associated with the dissolved phase exhibited a seasonal pattern, the fraction associated with the suspended solids showed less seasonality. In the dissolved phase, the overall removal efficiency in summer ranged from 70% to 85% for salicylic acid (SAL), methyl dihydrojasmonate, caffeine (CAF), ketoprofen and triclosan, whereas in winter it declined for most of the PPCPs to between 30% and 50%, except for CAF and SAL (>80%) and carbamazepine and butylated hydroxyl toluene (11-18%). In the suspended solids, the removal exceeded 80% for most of the target PPCPs. The efficiency of the different treatment steps was also compound-dependent, but the SF CW generally exhibited the highest removal efficiency for most of the contaminants analyzed. The characterization of the organic matter retained in the wetland gravel beds revealed the occurrence of hydrophobic contaminants such as phthalate esters and fragrances at moderate concentrations (i.e., up to 3.5 μg kg−1), which declined strongly over the course of the different treatment steps. In the SF CW, the net mass accumulation rates of tonalide and galaxolide were 4 and 23 g y−1 respectively, whereas in the SSF CW they were 0.3 and 1.8 g y−1 respectively. 相似文献
502.
洞庭湖退田还湖区不同土地利用方式对土壤养分库的影响 总被引:3,自引:0,他引:3
以钱粮湖垸为例,研究了洞庭湖退田还湖区的林地(Ⅰ)、园地(Ⅱ)、旱地(Ⅲ)、水田(Ⅳ)和荒地(Ⅴ)等不同土地利用方式下的土壤养分含量、养分库综合指数以及养分相关性。研究表明:土壤养分分布的表聚效应明显,0~50 cm土层土壤有机质含量为3.40~32.32 g/kg,全氮、水解氮含量为2.23~9.71 g/kg、12.95~112.00 mg/kg,全磷、速效磷含量为29.50~69.35 g/kg、4.15~75.68 mg/kg,全钾、速效钾含量为603~3069 g/kg、37.70~217.50 mg/kg;林地土壤全氮含量最高,有机质含量最低,水田有机质、全钾及速效磷含量均最高,旱地水解氮含量最高,而荒地土壤全氮、全磷、全钾、水解氮及水解磷均最低;土壤养分库综合指数变化范围为24.33~295.93,排序为IⅣ(231.96)>IⅢ(193.46)>IⅡ(70.90)>IⅠ(59.57)>IⅤ(35.59);土壤养分要素的相关性分析结果表明,有机质与全磷、全磷与速效磷、全氮与全钾、水解氮与速效磷均呈显著正相关关系,相关系数分别为 0.5760、0.5961、0.6864 和 0.5701。 相似文献
503.
Morrice JA Danz NP Regal RR Kelly JR Niemi GJ Reavie ED Hollenhorst T Axler RP Trebitz AS Cotter AM Peterson GS 《Environmental management》2008,41(3):347-357
A better understanding of relationships between human activities and water chemistry is needed to identify and manage sources
of anthropogenic stress in Great Lakes coastal wetlands. The objective of the study described in this article was to characterize
relationships between water chemistry and multiple classes of human activity (agriculture, population and development, point
source pollution, and atmospheric deposition). We also evaluated the influence of geomorphology and biogeographic factors
on stressor-water quality relationships. We collected water chemistry data from 98 coastal wetlands distributed along the
United States shoreline of the Laurentian Great Lakes and GIS-based stressor data from the associated drainage basin to examine
stressor-water quality relationships. The sampling captured broad ranges (1.5–2 orders of magnitude) in total phosphorus (TP),
total nitrogen (TN), dissolved inorganic nitrogen (DIN), total suspended solids (TSS), chlorophyll a (Chl a), and chloride; concentrations were strongly correlated with stressor metrics. Hierarchical partitioning and all-subsets
regression analyses were used to evaluate the independent influence of different stressor classes on water quality and to
identify best predictive models. Results showed that all categories of stress influenced water quality and that the relative
influence of different classes of disturbance varied among water quality parameters. Chloride exhibited the strongest relationships
with stressors followed in order by TN, Chl a, TP, TSS, and DIN. In general, coarse scale classification of wetlands by morphology (three wetland classes: riverine, protected,
open coastal) and biogeography (two ecoprovinces: Eastern Broadleaf Forest [EBF] and Laurentian Mixed Forest [LMF]) did not
improve predictive models. This study provides strong evidence of the link between water chemistry and human stress in Great
Lakes coastal wetlands and can be used to inform management efforts to improve water quality in Great Lakes coastal ecosystems. 相似文献
504.
Expert Perceptions of Approaches to Protecting Isolated Wetlands in the Northeastern United States
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Kristin Floress Mary Beth Kolozsvary Jean Mangun 《Journal of the American Water Resources Association》2017,53(5):1048-1061
In this article, we describe how protecting vernal pools was discussed by experts in the northeastern United States (U.S) within the context of a theoretical policy framework. We offer insight about characteristics of feasible vernal pool policy solutions, and identify gaps in our understanding, particularly regarding conditions in states currently lacking specific vernal pool protections. Vernal pools are geographically isolated, intermittent wetlands that provide important habitat for a variety of plants and animals. Many may not be federally protected as a result of judicial decisions over the past two decades, and the rule intended to clarify what qualifies for federal protection is currently being reviewed by the courts. Thus, state or local policy approaches may be alternatives to conserving vernal pools. We interviewed vernal pool experts in the northeastern U.S. regarding approaches to vernal pool protection and analyzed their perceptions through the lens of Kingdon's ( 2011 ) multiple streams policy development framework. The framework denotes 13 characteristics of three processes associated with policy development: problem identification, policy solution development, and the impacts of politics. While analyzed for all 13 components, we found participants most often discussed feasibility of policy formulation and implementation, particularly with regard to protecting vernal pools of high value while also remaining within the bounds of what public opinion supports. 相似文献
505.
The capacity of a full-scale reclamation pond-constructed wetland (CW) system to eliminate 27 emerging contaminants (i.e. pharmaceuticals, sunscreen compounds, fragrances, antiseptics, fire retardants, pesticides, and plasticizers) and the seasonal occurrence of these contaminants is studied. The compounds with the highest concentrations in the secondary effluent are diclofenac, caffeine, ketoprofen, and carbamazepine. The results show that the constructed wetland (61%) removes emerging contaminants significantly more efficiently than the pond (51%), presumably due to the presence of plants (Phragmites and Thypa) as well as the higher hydraulic residence time (HRT) in the CW. A greater seasonal trend to the efficient removal of these compounds is observed in the pond than in the CW. The overall mass removal efficiency of each individual compound ranged from 27% to 93% (71% on average), which is comparable to reported data in advanced treatments (photo-fenton and membrane filtration). The seasonal average content of emerging contaminants in the river water (2488 ng L−1) next to the water reclamation plant is found to be higher than the content in the final reclaimed water (1490 ng L−1), suggesting that the chemical quality of the reclaimed water is better than available surface waters. 相似文献
506.
Federico Antolini Eric Tate Brent Dalzell Nathan Young Kris Johnson Peter L. Hawthorne 《Journal of the American Water Resources Association》2020,56(1):161-179
Best management practices (BMPs) play an important role in improving impaired water quality from conventional row crop agriculture. In addition to reducing nutrient and sediment loads, BMPs such as fertilizer management, reduced tillage, and cover crops could alter the hydrology of agricultural systems and reduce surface water runoff. While attention is devoted to the water quality benefits of BMPs, the potential co‐benefits of flood loss reduction are often overlooked. This study quantifies the effects of selected commonly applied BMPs on expected flood loss to agricultural and urban areas in four Iowa watersheds. The analysis combines a watershed hydrologic model, hydraulic model outputs, and a loss estimation model to determine relationships between hydrologic changes from BMP implementations and annual economic flood loss. The results indicate a modest reduction in peak discharge and economic loss, although loss reduction is substantial when urban centers or other high‐value assets are located downstream in the watershed. Among the BMPs, wetlands, and cover crops reduce losses the most. The research demonstrates that watershed‐scale implementation of agricultural BMPs could provide benefits of flood loss reduction in addition to water quality improvements. 相似文献
507.
The small playa-lakes and other saline wetlands of Monegros, scattered over a dry area with winter cereal monoculture, are threatened by the settlement of new irrigation districts and other kinds of human pressure. Enforcing the protection rules of European Union in these valuable habitats requires, first, their delimitation and monitoring. This article shows how these tasks can be undertaken using remote sensing in conjunction with field observations. A series of Landsat images covering different seasons provided a comprehensive view of these wetlands encompassing their changing facies, hydrologic regime, state of conservation, and functional status. Remotely-sensed data were the primary, and in most cases the only available, source of consistent information. Our approach can help planning and surveying for the implementation of saline wetland protection measures in harmony with the conterminous agricultural areas. 相似文献
508.
509.
Floods continue to pose the greatest threat to the property and safety of human communities among all natural hazards in the United States. This study examines the relationship between the built environment and flood impacts in Texas, which consistently sustains the most damage from flooding of any other state in the country. Specifically, we calculate property damage resulting from 423 flood events between 1997 and 2001 at the county level. We identify the effect of several built environment measures, including wetland alteration, impervious surface, and dams on reported property damage while controlling for biophysical and socio-economic characteristics. Statistical results suggest that naturally occurring wetlands play a particularly important role in mitigating flood damage. These findings provide guidance to planners and flood managers on how to alleviate most effectively the costly impacts of foods at the community level. 相似文献
510.
利用静态箱/气相色谱法,观测了生长季(5~9月)三江平原小叶章沼泽化草甸H2S和COS的释放动态,结果表明,H2S、COS的排放通量具有季节和日变化规律,小叶章沼泽化草甸H2S的平均释放通量为0.34μg·(m2·h)-1,COS的平均释放通量为-0.29μg·(m2·h)-1;在生长季,小叶章沼泽化草甸表现为H2S的源,COS的汇.小叶章的生长过程对H2S、COS的排放影响显著,在小叶章生长旺盛期,H2S出现排放峰值,COS出现吸收高峰,H2S和COS的释放通量呈负相关. 相似文献