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931.
稠油采出水回用热采锅炉供水的处理工艺设计 总被引:3,自引:0,他引:3
运用混凝沉降、溶气浮选、粗精过滤和弱酸软化方法对稠油采出水进行深度处理。可达到热采锅炉用水指标 ,回用热采锅炉供水 ;生产装置产生的污水、污油、污泥均回收利用。笔者总结了流程选择、工艺配置、新工艺的采用、工艺及自控设计特点 ,为今后污水处理设计提供借鉴。 相似文献
932.
分指数分级评分叠加法在水质评价中的应用 总被引:1,自引:0,他引:1
提出了一种新的具有明确物理意义、且计算简单的“分指数分级评分叠加法”,讨论了该方法评价的表示方法,并给出了应用实例。 相似文献
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936.
A fuzzy logic approach has been developed to assess the groundwater pollution levels below agricultural fields. The data collected
for Kumluca Plain of Turkey have been utilized to develop the approach. The plain is known with its intensive agricultural
activities, which imply excessive application of fertilizers. The characteristics of the soils and underlying groundwater
for this plain were monitored during the years 1999 and 2000. Additionally, an extensive field survey related to the types
and yields of crops, fertilizer application and irrigation water was carried out. Both the soil and groundwater have exhibited
high levels of nitrogen, phosphorus and salinity with considerable spatial and temporal variations. The pollution level of
groundwater at several established stations within the plain were assessed using Fuzzy Logic. Water Pollution Index (WPI)
values are calculated by Fuzzy Logic utilizing the most significant groundwater pollutants in the area namely nitrite, nitrate
and orthophosphate together with the groundwater vulnerability to pollution. The results of the calculated WPI and the monitoring
study have yielded good agreement. WPI indicated high to moderate water pollution levels at Kumluca plain depending on factors
such as agricultural age, depth to groundwater, soil characteristics and vulnerability of groundwater to pollution. Fuzzy
Logic approach has shown to be a practical, simple and useful tool to assess groundwater pollution levels. 相似文献
937.
Use of Maryland Biological Stream Survey Data to Determine Effects of Agricultural Riparian Buffers on Measures of Biological Stream Health 总被引:1,自引:0,他引:1
This study was undertaken to determine the importance of riparian buffers to stream ecology in agricultural areas. The original
Maryland Biological Stream Survey (MBSS) data set was partitioned to represent agricultural sites in Maryland's Coastal Plain
and Piedmont regions. ANOVA, multiple linear regression (MLR), and CART regression tree models were developed using riparian
and site catchment landscape characteristics. MBSS data were both stratified by physiographic region and analyzed as a combined
data set. All models indicated that land management at the site was not the controlling factor for fish IBIs (FIBI) at that
site and, hence, using FIBI to evaluate site-scale factors would not be a prudent procedure. Measures of instream habitat
and location in the stream network were the dominant explanatory factors for FIBI models. Both CART and MLR models indicated
that forest buffers were influential on benthic IBIs (BIBI). Explanatory variables reflected instream conditions, adjacent
landscape influence, and chemistry in the Coastal Plains sites, all of which are relatively site specific. However, for Piedmont
sites, hydrologic factors were important, in addition to adjacent landscape influence, and chemistry. Both Coastal Plain and
Piedmont CART models identified several hydrologic factors, emphasizing the dominant control of hydrology on the physical
habitat index (PHI). Riparian buffers were a secondary influence on PHI in the Coastal Plain, but not in the Piedmont. Between
40% and 70% of the variation in FIBI, BIBI, and PHI was explained by the “easily obtainable” variables available from the
MBSS data set. While these are empirical results specific to Maryland, the general findings are of use to other locations
where the establishment of forest buffers is considered as an aquatic ecosystem restoration measure. 相似文献
938.
Moving Beyond Strawmen and Artificial Dichotomies: Adaptive Management When an Endangered Species Uses an Invasive One 总被引:1,自引:1,他引:0
Daniel Simberloff 《Journal of Agricultural and Environmental Ethics》2009,22(1):73-80
Evans et al. (Journal of Agricultural and Environmental Ethics, 2008) have attempted to enmesh me in their dispute with the Florida Bureau of Invasive Plant Management about a specific
system, Kings Bay/Crystal River. In so doing, they repeatedly mischaracterize my positions in order to depict, incorrectly,
invasion biology as monolithic and me as a representative of one extreme of a false dichotomy about management of introduced
species. In addition, they introduce an issue irrelevant in this case (extinctions) and cite incorrect data. Proposing to
manage people, manatees, introduced plants, and cyanobacteria in Kings Bay by participative adaptive management, they ignore
the fact that living organisms can both disperse autonomously and hitchhike. Finally, they present few details on any aspect
of their management proposal and do not address the myriad problems that have beset previous attempts at scientific adaptive
management, especially at large scales. Until such a management approach is fleshed out and implemented, it is impossible
to assess its validity for Kings Bay, and it is very premature to suggest it as a general model for dealing with invasive
species disputes. 相似文献
939.
Sanjiv Kumar Venkatesh Merwade 《Journal of the American Water Resources Association》2009,45(5):1179-1196
Abstract: Impact of watershed subdivision and soil data resolution on Soil Water Assessment Tool (SWAT) model calibration and parameter uncertainty is investigated by creating 24 different watershed model configurations for two study areas in northern Indiana. SWAT autocalibration tool is used to calibrate 14 parameters for simulating seven years of daily streamflow records. Calibrated parameter sets are found to be different for all 24 watershed configurations, however in terms of calibrated model output, their effect is minimal. In some cases, autocalibration is followed by manual calibration to correct for low flows, which were underestimated during autocalibration. In addition to normal validation using four years of streamflow data for each calibrated parameter set, cross‐validation (using a calibrated parameter set from one model configuration to validate observations using another configuration) is performed to investigate the effect of different model configurations on streamflow prediction. Results show that streamflow output during cross‐validation is not affected, thus highlighting the non‐unique nature of calibrated parameters in hydrologic modeling. Finally, parameter uncertainty is investigated by extracting good parameter sets during the autocalibration process. Parameter uncertainty analysis suggests that significant parameters show very narrow range of uncertainty across different watershed configurations compared with nonsignificant parameters. Results from recalibration of some configurations using only six significant parameters were comparable to that from calibration using 14 parameters, suggesting that including fewer significant parameters could reduce the uncertainty arising from model parameters, and also expedite the calibration process. 相似文献
940.
J. M. Evans A. C. Wilkie J. Burkhardt 《Journal of Agricultural and Environmental Ethics》2009,22(2):169-180
Our recent paper advocating adaptive management of invasive nonnative species (INS) in Kings Bay, Florida received detailed
responses from both Daniel Simberloff, a prominent invasion biologist, and Mark Sagoff, a prominent critic of invasion biology.
Simberloff offers several significant lines of criticism that compel detailed rebuttals, and, as such, most of this reply
is dedicated to this purpose. Ultimately, we find it quite significant that Simberloff, despite his other stated objections
to our paper, apparently agrees with our argument that proposals for alternative management of established INS (i.e., alternatives
to minimization/eradication) should not be rejected on an a␣priori basis. We argue that more specific development and application
of adaptive approaches toward INS management, whether in Kings Bay or other appropriate case studies, would be facilitated
if ecosystem managers and invasion biologists follow Simberloff’s lead on this key point. While Sagoff largely shares (and,
indeed, served as a primary source for developing) our general arguments that challenge common moral and scientific assumptions
associated with invasion biology, he does question our suggestion that participatory adaptive management provides an appropriate
framework for approaching environmental problems in which science and politics are inherently entangled. We attempt to answer
this criticism through a brief sketch of what participatory adaptive management might look like for Kings Bay and how such
an approach would differ from past management approaches. 相似文献