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81.
Silva Lídia Gaudêncio Ribeiro Costa Elizângela Pinheiro Starling Maria Clara Vieira Martins dos Santos Azevedo Taíza Bottrel Sue Ellen Costa Pereira Renata Oliveira Sanson Ananda Lima Afonso Robson José Cassia Franco Amorim Camila C. 《Environmental science and pollution research international》2021,28(19):24067-24078
Environmental Science and Pollution Research - The goal of this work was to evaluate the performance of the LED irradiated photo-Fenton process on the removal of (i) estrogenic activity and (ii)... 相似文献
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This article identifies key questions and challenges for geomorphologists in investigating coupled feedbacks in human–landscape systems. While feedbacks occur in the absence of human influences, they are also altered by human activity. Feedbacks are a key element to understanding human-influenced geomorphic systems in ways that extend our traditional approach of considering humans as unidirectional drivers of change. Feedbacks have been increasingly identified in Earth-environmental systems, with studies of coupled human–natural systems emphasizing ecological phenomena in producing emerging concepts for social–ecological systems. Enormous gaps or uncertainties in knowledge remain with respect to understanding impact-feedback loops within geomorphic systems with significant human alterations, where the impacted geomorphic systems in turn affect humans. Geomorphology should play an important role in public policy by identifying the many diffuse and subtle feedbacks of both local- and global-scale processes. This role is urgent, while time may still be available to mitigate the impacts that limit the sustainability of human societies. Challenges for geomorphology include identification of the often weak feedbacks that occur over varied time and space scales ranging from geologic time to single isolated events and very short time periods, the lack of available data linking impact with response, the identification of multiple thresholds that trigger feedback mechanisms, the varied tools and metrics needed to represent both physical and human processes, and the need to collaborate with social scientists with expertise in the human causes of geomorphic change, as well as the human responses to such change. 相似文献
84.
Le MH Buddenbaum JE Burns RE Shonka JJ Gaffney SH Donovan EP Flack SM Widner TE 《Journal of environmental monitoring : JEM》2011,13(10):2735-2747
From 1999 through 2010, a team of scientists and engineers systematically reviewed approximately eight million classified and unclassified documents at Los Alamos National Laboratory (LANL) that describe historical off-site releases of radionuclides and chemicals in order to determine the extent to which a full-scale dose reconstruction for releases is warranted and/or feasible. As a part of this effort, a relative ranking of historical airborne and waterborne radionuclide releases from LANL was established using priority index (PI) values that were calculated from estimated annual quantities released and the maximum allowable effluent concentrations according to The U.S. Nuclear Regulatory Commission (USNRC). Chemical releases were ranked based on annual usage estimates and U.S. Environmental Protection Agency (USEPA) toxicity values. PI results for airborne radionuclides indicate that early plutonium operations were of most concern between 1948 and 1961, in 1967, and again from 1970 through 1973. Airborne releases of uranium were found to be of most interest for 1968, from 1974 through 1978, and again in 1996. Mixed fission products yielded the highest PI value for 1969. Mixed activation product releases yielded the highest PI values from 1979 to 1995. For waterborne releases, results indicate that plutonium is of most concern for all years evaluated with the exception of 1956 when (90)Sr yielded the highest PI value. The prioritization of chemical releases indicate that four of the top five ranked chemicals were organic solvents that were commonly used in chemical processing and for cleaning. Trichloroethylene ranked highest, indicating highest relative potential for health effects, for both cancer and non-cancer effects. Documents also indicate that beryllium was used in significant quantities, which could have lead to residential exposures exceeding established environmental and occupational exposure limits, and warrants further consideration. In part because of the close proximity of residents to LANL, further study of historical LANL releases and the potential impact to public health is recommended for those materials with the largest priority index values; namely, plutonium, uranium, and selected chemicals. 相似文献
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The increased popularity of bridge employment has raised questions about its consequences for well‐being in late adult life. This research explored the consequences of bridge employment for the level of life satisfaction of older adults during the retirement transition period. Changes in life satisfaction were considered to be a function of the different intentions and motives for taking bridge jobs. Furthermore, the impact of bridge employment was empirically examined conditional on the voluntariness of the exit from the career job. Panel data on Dutch retirees (N = 1248) were investigated using conditional change models. The results demonstrate that older adults willing to prolong their work careers but unable to find bridge jobs reported lower levels of life satisfaction compared with full retirees not considering bridge employment. In addition, participation in bridge employment for financial motives was associated with decreases in life satisfaction compared with postretirement working based on intrinsic motives. Moreover, compared with voluntary retirement, involuntary retirement was detrimental to life satisfaction, but participation in a bridge job was found to mitigate this negative shock. These findings contribute to the understanding of the consequences of various postretirement employment trajectories for older individuals. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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Identification of Putative Geographically Isolated Wetlands of the Conterminous United States 下载免费PDF全文
Charles R. Lane Ellen D'Amico 《Journal of the American Water Resources Association》2016,52(3):705-722
Geographically isolated wetlands (GIWs) are wetlands completely surrounded by uplands. While common throughout the United States (U.S.), there have heretofore been no nationally available, spatially explicit estimates of GIW extent, complicating efforts to understand the myriad biogeochemical, hydrological, and habitat functions of GIWs and hampering conservation and management efforts at local, state, and national scales. We used a 10‐m geospatial buffer as a proxy for hydrological or ecological connectivity of National Wetlands Inventory palustrine and lacustrine wetland systems to nationally mapped and available stream, river, and lake data. We identified over 8.3 million putative GIWs across the conterminous U.S., encompassing nearly 6.5 million hectares of wetland resources (average size 0.79 ± 4.81 ha, median size 0.19 ha). Putative GIWs thus represent approximately 16% of the freshwater wetlands of the conterminous U.S. The water regime for the majority of the putative GIWs was temporarily or seasonally flooded, suggesting a vulnerability to ditching or hydrologic abstraction, sedimentation, or alterations in precipitation patterns. Additional analytical applications of this readily available geospatially explicit mapping product (e.g., hydrological modeling, amphibian metapopulation, or landscape ecological analyses) will improve our understanding of the abundance and extent, effect, connectivity, and relative importance of GIWs to other aquatic systems of the conterminous U.S. 相似文献
90.
Linking Theory and Practice for Restoration of Step-Pool Streams 总被引:1,自引:0,他引:1
Chin A Anderson S Collison A Ellis-Sugai BJ Haltiner JP Hogervorst JB Kondolf GM O'Hirok LS Purcell AH Riley AL Wohl E 《Environmental management》2009,43(4):645-661
Step-pools sequences are increasingly used to restore stream channels. This increase corresponds to significant advances in
theory for step-pools in recent years. The need for step-pools in stream restoration arises as urban development encroaches
into steep terrain in response to population pressures, as stream channels in lower-gradient areas require stabilization due
to hydrological alterations associated with land-use changes, and as step-pools are recognized for their potential to enhance
stream habitats. Despite an increasingly voluminous literature and great demand for restoration using step-pool sequences,
however, the link between theory and practice is limited. In this article, we present four unique cases of stream restoration
using step-pools, including the evolution of the approaches, the project designs, and adjustments in the system following
restoration. Baxter Creek in El Cerrito, California demonstrates an early application of artificial step-pools in which natural
adjustments occurred toward geomorphic stability and ecological improvement. Restoration of East Alamo Creek in a large residential
development near San Ramon, California illustrates an example of step-pools increasingly used in locations where such a channel
form would not naturally occur. Construction of a step-pool channel in Karnowsky Creek within the Siuslaw National Forest,
Oregon overcame constraints posed by access and the type and availability of materials; the placement of logs allowed natural
scouring below steps. Dry Canyon Creek on the property of the Mountains Restoration Trust in Calabasas, California afforded
a somewhat experimental approach to designing step-pools, allowing observation and learning in the future. These cases demonstrate
how theories and relationships developed for step-pool sequences over the past two decades have been applied in real-world
settings. The lessons from these examples enable us to develop considerations useful for deriving an appropriate course of
design, approval, and construction of artificial step-pool systems. They also raise additional fundamental questions concerning
appropriate strategies for restoration of step-pool streams. Outstanding challenges are highlighted as opportunities for continuing
theoretical work. 相似文献