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671.
Cougars (Puma concolor) are of considerable interest to wildlife biologists and the general public in midwestern North America, yet no researchers have modelled potential habitat in the region. We created a model of potential cougar habitat in 9 midwestern states using geospatial data, expert-opinion surveys, the analytical hierarchy process, and a GIS. About 8% of the study region contained highly favorable habitat (with favorability scores ≥75%) for cougars; the states of Arkansas (19%) and Missouri (16%) contained the highest proportions of potentially favorable habitat. We identified 6 large (≥2500 km2 in size), contiguous areas of highly favorable habitat for cougars. Model testing procedures indicated a valid model when compared to an independent set of cougar locations, a null dataset, and similar studies. Our model is useful as a planning tool to proactively address future human-cougar conflicts should cougars re-colonize the Midwest via subadult dispersal. 相似文献
672.
Mapping the location and extent of forest at risk from damaging agents or processes assists forest managers in prioritizing their planning and operational mitigation activities. In Australia, Bell Miner Associated Dieback (BMAD) refers to a form of canopy decline observed in eucalypt crowns occupied by colonies of bell miners (Manorina melanophrys). High densities of bell miners are associated with decreased avian abundance and diversity and an increase in psyllid abundance on crown foliage. BMAD has recently been nominated as a key threatening process in New South Wales (NSW). Consequently, a modelling system for predicting bell miner distribution in coastal eucalypt forests of NSW has been developed. The presence or absence of bell miners was recorded in 130 plots located within a 12,800 ha catchment study area containing a range of eucalypt forest types. The modelling system was produced by integrating a machine learning software suite (WEKA), and the statistical software R within the geographic resources analysis support system (GRASS) geographical information system (GIS). The variable modelled was the binary variable: presence or absence of bell minors. Six modelling techniques (Logistic regression; generalised additive models; two tree-based ensemble classification algorithms, random forest and Adaboost and Neural Networks) were integrated with airborne laser scanning; SPOT 5 and topographic derived variables. Model evaluation and parameter selection were measured by three threshold dependent measures (sensitivity, specificity and kappa) and the threshold independent Receiver Operator Curve (ROC) analysis. The final presence and absence maps were obtained through maximisation of the kappa statistic and applied at a resolution of 10 m across the entire catchment study area. For this data set, the most accurate algorithm for predicting the distribution of bell miner colonies was random forest (kappa = 0.84; ROC area under curve = 0.97). Variables most commonly selected in the six models were the laser scanning metrics; coefficient of variation, skewness, and the 10th and 90th percentiles derived from the shape of the height frequency distribution which, in turn, is directly influenced by vertical structure of the forest. An image textural statistic based on the shortwave infrared (SWIR) band of SPOT 5 was also commonly selected by the models. The SWIR band is sensitive to vegetation and soil moisture content. These models predicted that forest stands with a sparse eucalypt canopy over a moist, dense understorey were susceptible to being colonised by bell miners and hence BMAD. 相似文献
673.
Fragmentation drives tropical forest fragments to early successional states: A modelling study for Brazilian Atlantic forests 总被引:1,自引:0,他引:1
Land use leads to massive habitat destruction and fragmentation in tropical forests. Despite its global dimensions the effects of fragmentation on ecosystem dynamics are not well understood due to the complexity of the problem. We present a simulation analysis performed by the individual-based model FORMIND. The model was applied to the Brazilian Atlantic Forest, one of the world's biodiversity hot spots, at the Plateau of São Paulo. This study investigates the long-term effects of fragmentation processes on structure and dynamics of different sized remnant tropical forest fragments (1-100 ha) at community and plant functional type (PFT) level. We disentangle the interplay of single effects of different key fragmentation processes (edge mortality, increased mortality of large trees, local seed loss and external seed rain) using simulation experiments in a full factorial design.Our analysis reveals that particularly small forest fragments below 25 ha suffer substantial structural changes, biomass and biodiversity loss in the long term. At community level biomass is reduced up to 60%. Two thirds of the mid- and late-successional species groups, especially shade-tolerant (late successional climax) species groups are prone of extinction in small fragments. The shade-tolerant species groups were most strongly affected; its tree number was reduced more than 60% mainly by increased edge mortality. This process proved to be the most powerful of those investigated, explaining alone more than 80% of the changes observed for this group. External seed rain was able to compensate approximately 30% of the observed fragmentation effects for shade-tolerant species.Our results suggest that tropical forest fragments will suffer strong structural changes in the long term, leading to tree species impoverishment. They may reach a new equilibrium with a substantially reduced subset of the initial species pool, and are driven towards an earlier successional state. The natural regeneration potential of a landscape scattered with forest fragments appears to be limited, as external seed rain is not able to fully compensate for the observed fragmentation-induced changes. Our findings suggest basic recommendations for the management of fragmented tropical forest landscapes. 相似文献
674.
A. Bernatik P. SenovskyM. Pitt 《Journal of Loss Prevention in the Process Industries》2011,24(1):19-24
The aim of this article is to summarize the safety and security aspects of storing of Liquefied Natural Gas (LNG) as a potential alternative fuel. The contribution deals with possible scenarios of accidents associated with LNG storage facilities and with a methodology for the assessment of vulnerability of such facilities. The protection of LNG storage facilities as element of critical infrastructure should also be a matter of interest to the state. The study presents the results of determination of hazardous zones around LNG facilities in the event of various sorts of release. For calculations, the programs ALOHA, EFFECTS and TerEx were used and results obtained were compared. Scenarios modelled within this study represent a possible approach to the preliminary assessment of risk that should be verified by more detailed modelling (CFD). These scenarios can also be used for a quick estimation of areas endangered by an incident or accident. The results of modelling of the hazardous zones contribute to a reduction in risk of major accidents associated with these potential alternative energy sources. 相似文献
675.
676.
Iosif Botetzagias Chrisovaladis Malesios Anthi Kolokotroni Yiannis Moysiadis 《Journal of Environmental Planning and Management》2015,58(2):229-251
This paper aims to assess the relative importance of a NIMBY (‘Not-In-My-Back-Yard’) stance on an individual's opposition to the siting of a wind farm vis-à-vis other predictors, such as perceived effects (costs, risks and benefits associated with the project), perceived fairness of the siting decision and societal trust. Data originate from two case studies, a small wind farm of just two wind turbines in southern Greece and a mega-project of 153 turbines on the Greek island of Lesvos (aggregate N = 334). We use structural equation modelling (SEM) for testing the theoretically-suggested relations between the various constructs. We find that NIMBY is not the most important predictor of opposition while it is strongly correlated with other predictors, such as the perceived unfairness of the siting decision as well as the risks and costs associated with the wind farm. These latter findings undermine the common-sense idea that wishing a wind farm out of one's vicinity (‘Not-In-My-Back-Yard’) is an example of mere ‘free-riding’. Since the fit of the SEM models was found to be moderate, we discuss the limitations of our study and the implications of our findings as well as suggesting pathways for future research. 相似文献
677.
Fátima Lima Joana Portugal‐Pereira André F.P. Lucena Pedro Rochedo Jorge Cunha Manuel Lopes Nunes Alexandre Salem Szklo 《Natural resources forum》2015,39(3-4):175-190
This study estimated a series of indicators to assess the energy security of supply and global and local environmental impacts under different mitigation scenarios through 2050 in Brazil, designed with the integrated optimization energy system model MESSAGE‐BRAZIL. The assessment of interactions between environmental impacts and energy security dimensions was complemented through the application of life cycle assessment (LCA) methodology. Overall results imply energy security establishes more synergies than trade‐offs in increasingly stringent mitigation scenarios, especially patent within the sustainability dimension, which increases energy security and provides additional benefits regarding climate change mitigation and air pollution emissions. It is still necessary to extend analysis to other energy sectors in addition to the power supply sector and to promote a better understanding of repercussions of energy scenario expansion in energy security. 相似文献
678.
Dave D. White Amber Y. Wutich Kelli L. Larson Tim Lant 《Journal of Environmental Planning and Management》2015,58(4):616-630
Model-based decision support systems are increasingly used to link knowledge to action for environmental decision making. How stakeholders perceive uncertainty in models and visualisations affects their perceptions of credibility, relevance and usability of these tools. This paper presents a case study of water decision makers’ evaluations of WaterSim, a dynamic water simulation model presented in an immersive decision theatre environment. Results reveal that decision makers’ understandings of uncertainty in their evaluations of decision support systems reflect both scientific and political discourse. We conclude with recommendations for design and evaluation of decision support systems that incorporate decision makers' views. 相似文献
679.
Gardening has become a relevant contributor to the quality of life of suburbanites, as a source of leisure, to build a relationship with nature or to express a particular social identity. Nevertheless, water scarcity in the Mediterranean region has increased concerns about how demand should be managed to face future uncertainties, and watering the gardens has become an element for discussion in urban planning. This contribution presents the findings of a survey of permanent residents and secondary homeowners (n?=?230) in the suburban areas surrounding the city of Girona in the northeast of Catalonia (Spain). The area is a popular national and international tourist destination and a preferred place for second-home owners. We explore the main socio-demographic drivers for choosing an alternative watering source and we analyse if water-harvesting tank sizes properly meet net irrigation requirements. Results show that many water-harvesting tanks are oversized. The percentage of unemployed or retired household members, the estimated irrigation water needs of the garden and the education level directly influence the search for alternative sources of water. Moreover, social variables like interest in gardening, water conservation attitudes and household income indirectly influence the search for alternative sources of water. 相似文献
680.
为了探究茅洲河流域感潮河网面源污染空间分布特征和降雨径流污染规律,基于空间分析、统计分析与流域水动力-水质耦合模拟方法,对典型降雨情景下河网水质情况进行模拟分析,提出基于水质改善目标的生态补水点位空间布局优化策略.研究表明,层次聚类凝聚算法和K-均值法迭代组合可以较好地实现面源污染分级与分类;茅洲河各支流中,石岩渠、松岗河中上游等河道(段)由于面源污染负荷相对较高且缺乏生态补水,雨后水质恢复缓慢;基于补水总量不变原则,对生态补水方案进行局部优化,优化结果可使雨后受污染重点河道(段)水质恢复速度加快一倍以上,提高了流域水质的整体稳定性.研究结论可为进一步认识茅洲河流域水污染特征、实现流域水环境精细化管理提供支撑. 相似文献