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161.
Transferability of Species Distribution Models: a Functional Habitat Approach for Two Regionally Threatened Butterflies 总被引:3,自引:0,他引:3
Abstract: Numerous models for predicting species distribution have been developed for conservation purposes. Most of them make use of environmental data (e.g., climate, topography, land use) at a coarse grid resolution (often kilometres). Such approaches are useful for conservation policy issues including reserve-network selection. The efficiency of predictive models for species distribution is usually tested on the area for which they were developed. Although highly interesting from the point of view of conservation efficiency, transferability of such models to independent areas is still under debate. We tested the transferability of habitat-based predictive distribution models for two regionally threatened butterflies, the green hairstreak ( Callophrys rubi ) and the grayling ( Hipparchia semele ), within and among three nature reserves in northeastern Belgium. We built predictive models based on spatially detailed maps of area-wide distribution and density of ecological resources. We used resources directly related to ecological functions (host plants, nectar sources, shelter, microclimate) rather than environmental surrogate variables. We obtained models that performed well with few resource variables. All models were transferable—although to different degrees—among the independent areas within the same broad geographical region. We argue that habitat models based on essential functional resources could transfer better in space than models that use indirect environmental variables. Because functional variables can easily be interpreted and even be directly affected by terrain managers, these models can be useful tools to guide species-adapted reserve management. 相似文献
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164.
通过对环境问题产生的复杂性及环境侵权行为特征的剖析,阐述发当前各国环境立法中有关环境诉讼作出重大变革的必然性和现实意义。并指出环境法学理论的第一步发展和完善是市场经济进程中司法实践的需要和必然趋势。 相似文献
165.
Jones PD Newsted JL Henningsen G Slocomb J Giesy JP 《Environmental science and pollution research international》2005,12(4):189-198
Background, Aims and Scope The Rocky Mountain Arsenal (RMA) is a US Army facility located northeast of Denver, Colorado that has been listed on the
National Priorities List (NPL). It is currently being re-mediated under the authority of the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA) and the Superfund Amendments and Reauthorization Act of 1986 (SARA). As part
of the remediation activities at RMA, indications were found that a source of polychlorinated dibenzo-p-dioxins (PCDDs) and
polychlorinated dibenzofurans (PCDFs) had existed on the RMA. As a result, investigations were undertaken to assess the possible
nature and extent of any potential sources of PCDDs and PCDFs on the RMA site. In addition, other studies were conducted that
examined PCDD/PCDF contamination in the Denver area. The goal of these studies was to examine nature and extent of PCDD/PCDF
contamination both on the RMA as well as in the surrounding Denver area. The intent of this study was to characterize sources
of dioxins (PCDDs) and dibenzofurans (PCDFs) at low environmental concentrations which might have originated from diffuse
sources in the Denver Colorado area and in particular, the Rocky Mountain Arsenal (RMA) using Principal Component Analysis
(PCA).
Methods Over 200 soil samples were collected from the RMA and the Denver area. From the RMA, soil was collected as part of three
studies that included a (1) random site-wide sampling of the RMA, (2) soils from the Western Tier Parcel (WTP), and (3) soils
from Historic Use areas. Denver area soil samples were collected from five different land use categories: Residential, Agricultural,
Open Space, Commercial, and Industrial. PCA was conducted on concentrations of 17 2,3,7,8-substuituted PCDD and PCDF congeners
in 220 soil samples collected from the RMA and the Denver Front Range region.
Results and Discussion PCA demonstrated the presence of possible minor sources of dioxins on the RMA. Current remediation efforts on RMA will result
in the removal of these sources. Samples from the RMA were identified by the presence of a congener profile containing higher
chlorinated PCDFs while the Denver Front Range areas were characterized by the presence of higher chlorinated PCDD congeners.
The presence of a PCDF signature for the RMA samples does not necessarily indicate a major source of these contaminants on-site.
Indeed, the relatively diffuse nature of the sample clusters would argue strongly against the presence of a single large source.
Instead, the predominance of the PCDF congeners probably indicates the mixed industrial activities that took place on and
near the site.
Conclusion PCA results indicate that PCDD/PCDF profiles in soils collected from the RMA differed from those collected from the outlying
Denver areas but that a major source of these contaminants was not present. Rather, the diffuse nature of sample clusters
from the PCA indicated that the congener profile of RMA samples was most likely a result of the mixed industrial activities
that historically have taken place on and near the site. PCA also indicated that many of the 'open area' (peripheral site-wide)
RMA soils samples did not differ from Denver are reference congener profiles. This finding was also true for samples collected
from the WTP that were essentially indistinguishable from Off-RMA reference samples. In addition, total TEQ concentrations
in soils collected from WTP were similar to those measured in soils collected from the Denver Front Range areas indicating
that lack of a major source of PCDD/PCDF within the WTP zones of the RMA.
Recommendation and Outlook Analytical as well as statistical results of the soil congener data indicate that the WTP soils are indistinguishable from
soils collected from non-industrial areas in the Denver area. This finding would support the recent 'de-listing' of the WTP
from the other RMA areas and its' transfer to other authorities in the Denver area. 相似文献
166.
中美高等环境类专业设置比较研究 总被引:3,自引:0,他引:3
对美国高等环境类专业设置现状进行了初步调查和统计分析,并与我国高等环境类专业设置状况进行比较研究.研究表明,高等环境类专业设置存在一定的差异性,而且显示出美国高等环境类专业设置具有某些明显特点,主要表现在:专业设置种类数量多、面广且多元化;人文社会科学型专业的比例较大;设置了培养环境教育师资人才的专业;环境健康领域在专业设置中得到了高度重视;“综合型”人才培养目标在专业设置中更为突出.这些特点可以为我国高等环境类专业设置的改革和调整以及高等环境教育发展决策提供参考依据. 相似文献
167.
管道燃气火灾爆炸事故树分析 总被引:3,自引:0,他引:3
在调查与研究的基础上,采用安全系统工程的方法,对城市管道燃气火灾爆炸事故进行了事故树分析。文中给出的由201个基本原因事件和81个逻辑门所构成的管道燃气火灾爆炸事故树分析图,直观地表现了各可能导致顶上事件发生的初始因素及其逻辑关系,经对FT的求解,得出了243个最小径集,指明了预防事故发生的可能途径;在对采用各可能预防途径的可行性,经济性,可操作性进行充分的考虑与比较后,确定出了城市管道燃气火灾爆炸事故预防措施,并做出安全检查表,以供现场实施使用;最后提出了提高燃气安全运行水平的建议。 相似文献
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目前,我国上市及申请再融资企业(或公司)环境保护核查工作已经历了启动、规范和研究发展三个阶段。本文分析了上市公司环境保护核查工作与开发建设项目环境影响评价、竣工验收监测或调查的关系,三者之间既有区别又有紧密的联系。指出重污染行业企业也存在生态影响问题,有必要对其生态保护与建设工作进行核查,并提出了生态保护与建设核查的主要内容。 相似文献
170.