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321.
Granger SJ Bol R Dixon L Naden PS Old GH Marsh JK Bilotta G Brazier R White SM Haygarth PM 《Journal of environmental monitoring : JEM》2010,12(5):1159-1169
A study was undertaken on drained and undrained 1 ha grassland lysimeters to assess the effectiveness of multiple novel tracing techniques in understanding how agricultural slurry waste moves from land to water. Artificial fluorescent particles designed to mimic the size and density of organic slurry particles were found to move off the grassland via inter-flow (surface + lateral through-flow) and drain-flow. Where both pathways were present the drains carried the greater number of particles. The results of the natural fluorescence and δ13C of water samples were inconclusive. Natural fluorescence was higher from slurry-amended lysimeters than from zero-slurry lysimeters, however, a fluorescence decay experiment suggested that no slurry signal should be present given the time between slurry application and the onset of drainage. The δ13C values of >0.7 microm and <0.7 microm material in drainage were varied and unrelated to discharge. The mean value of >0.7 microm δ13C in water from the drain-flow pathways was higher from the lysimeter which had received naturally enriched maize slurry compared to the lysimeter which received grass slurry indicating a contribution of slurry-derived material. Values of <0.7 microm δ13C from the same pathway, however, produced counter intuitive trends and may indicate that different fractions of the slurry have different δ13C values. 相似文献
322.
Adam Crawford Jon Holliday Chester Merrick John Brayan Mark van Asten Lee Bowling 《Environmental monitoring and assessment》2017,189(4):202
An unusual bloom of Chrysosporum ovalisporum (basionym Aphanizomenon ovalisporum) occurred for the first time in the Murray River and distributary rivers in New South Wales, Australia, from mid-February to early June 2016. At its greatest extent, it contaminated a combined river length of ca. 2360 km. Chrysosporum ovalisporum usually comprised >99% of the total bloom biovolume at most locations sampled, which at times exceeded 40 mm3 l?1. The origins of the bloom were most likely reservoirs on the upper Murray River, with cyanobacterial-infested water released from them contaminating the river systems downstream. An integrated approach using three analytical methods: (1) identification and enumeration by microscopy, (2) multiplex quantitative polymerase chain reaction (qPCR), and (3) toxin analysis, was used to obtain data for the assessment of risk to water users and management of the bloom. qPCR indicated some cyrA and stxA genes responsible for cylindrospermopsin and saxitoxin biosynthesis respectively were present, but mostly below the level of quantification. No mcyE genes for microcystin biosynthesis were detected. Toxin analysis also revealed that cylindrospermopsin, saxitoxin and microcystin were all below detection. Lack of measurable toxicity in a species usually considered a cylindrospermopsin producer elsewhere meant the possibility of relaxing management guidelines; however, high (Red) alerts needed to be maintained due to risk to water users from other biohazards potentially produced by the cyanobacteria such as contact irritants. A three-tiered monitoring strategy is suggested for monitoring cyanobacterial blooms to provide enhanced data for bloom management. 相似文献
323.
Implementing geologic storage of CO2 at a material scale (ca. 1 Gt C/year) will require an industry comparable in size to the current oil and gas industry and a workforce trained in subsurface engineering. Since the same technologies that apply to hydrocarbon production apply to the subsurface storage of CO2, petroleum engineering (PE) graduates will be valuable candidates to work in the carbon storage industry. We expect however that the demand for PEs from the oil and gas industry will increase, and that already strained educational capacity will not be sufficient to supply both industries. Thus we advocate building new targeted educational infrastructure. We present a model curriculum based on an existing accredited multidisciplinary degree program. This program combines the fundamentals of petroleum engineering with the subsurface architecture emphasis of geology and the environmental perspective of hydrogeology. We indicate key elements of this program that could be integrated with other, more traditional undergraduate engineering majors that also deal with the subsurface. 相似文献
324.
Water is scarce in many regions of the world, clean water is difficult to find in most developing countries, there are conflicts
between irrigation needs and urban demands, and there is wide debate over appropriate means of resolving these problems. Similarly,
in China, there is limited understanding of the ways in which people, groups, and institutions contribute to, are affected
by, and respond to changes in water quantity and quality. We use the example of the Yellow River basin to argue that these
social, managerial, and policy dimensions of the present water problems are significant and overshadow the physical ones.
Despite this, they receive relatively little attention in the research agenda, particularly of the lead agencies in the management
of the Yellow River basin. To this end, we ask ten research questions needed to address the policy needs of water management
in the basin, split into two groups of five. The first five relate to the importance of water in this basin and the changes
that have affected water problems and will continue to do so. The second five questions represent an attempt to explore possible
solutions to these problems. 相似文献
325.
Michael A. Butkus Jon C. Malinowski 《Journal of the American Water Resources Association》2023,59(1):197-211
Comprehensive analyses of long-term region-specific water resources developments could offer new insights for contemporary water resources planners and decision makers. The objective of this work was to analyze water supply development at the United States Military Academy (USMA) during the 19th and early 20th Centuries through the lens of selected modern water resources planning and management practices. Analysis of water usage, population, and technological growth revealed that changes in technology had a greater influence on total water withdrawals than an increase in population. The USMA water supply system evolved incrementally over much of the 141-year study period and failure to adequately recognize shortcomings in water supply options resulted in several suboptimal decisions. Communications and enhanced stakeholder participation might have resulted in alternative decisions. 相似文献
326.
Historic Fire Regime in Southern California Shrublands 总被引:5,自引:0,他引:5
327.
Johnson LL Ylitalo GM Arkoosh MR Kagley AN Stafford C Bolton JL Buzitis J Anulacion BF Collier TK 《Environmental monitoring and assessment》2007,124(1-3):167-194
To better understand the dynamics of contaminant uptake in outmigrant juvenile salmon in the Pacific Northwest, concentrations
of polychlorinated biphenyls (PCBs), DDTs, polycylic aromatic hydrocarbons (PAHs) and organochlorine pesticides were measured
in tissues and prey of juvenile chinook and coho salmon from several estuaries and hatcheries in the US Pacific Northwest.
PCBs, DDTs, and PAHs were found in tissues (whole bodies or bile) and stomach contents of chinook and coho salmon sampled
from all estuaries, as well as in chinook salmon from hatcheries. Organochlorine pesticides were detected less frequently.
Of the two species sampled, chinook salmon had the highest whole body contaminant concentrations, typically 2--5 times higher
than coho salmon from the same sites. In comparison to estuarine chinook salmon, body burdens of PCBs and DDTs in hatchery
chinook were relatively high, in part because of the high lipid content of the hatchery fish. Concentrations of PCBs were
highest in chinook salmon from the Duwamish Estuary, the Columbia River and Yaquina Bay, exceeding the NOAA Fisheries' estimated
threshold for adverse health effects of 2400 ng/g lipid. Concentrations of DDTs were especially high in juvenile chinook salmon
from the Columbia River and Nisqually Estuary; concentrations of PAH metabolites in bile were highest in chinook salmon from
the Duwamish Estuary and Grays Harbor. Juvenile chinook salmon are likely absorbing some contaminants during estuarine residence
through their prey, as PCBs, PAHs, and DDTs were consistently present in stomach contents, at concentrations significantly
correlated with contaminant body burdens in fish from the same sites. 相似文献
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