全文获取类型
收费全文 | 81篇 |
免费 | 0篇 |
专业分类
废物处理 | 1篇 |
环保管理 | 15篇 |
综合类 | 7篇 |
基础理论 | 28篇 |
环境理论 | 1篇 |
污染及防治 | 18篇 |
评价与监测 | 6篇 |
社会与环境 | 4篇 |
灾害及防治 | 1篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 2篇 |
2020年 | 3篇 |
2018年 | 4篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2014年 | 3篇 |
2013年 | 13篇 |
2012年 | 9篇 |
2011年 | 5篇 |
2010年 | 2篇 |
2009年 | 6篇 |
2008年 | 1篇 |
2007年 | 3篇 |
2006年 | 3篇 |
2005年 | 2篇 |
2004年 | 1篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2001年 | 1篇 |
2000年 | 1篇 |
1999年 | 1篇 |
1998年 | 4篇 |
1988年 | 1篇 |
1985年 | 2篇 |
1981年 | 1篇 |
1976年 | 2篇 |
排序方式: 共有81条查询结果,搜索用时 0 毫秒
1.
Suescún Diego Villegas Juan Camilo León Juan Diego Flórez Claudia P. García-Leoz Vanessa Correa-Londoño Guillermo A. 《Regional Environmental Change》2017,17(3):827-839
Regional Environmental Change - Mountain ecosystems provide key services to a large portion of the population in the tropics. However, they are particularly vulnerable to regional environmental... 相似文献
2.
3.
Carlos Neira Francisco Delgadillo-Hinojosa Alberto Zirino Guillermo Mendoza Lisa A. Levin Magali Porrachia 《Chemistry and Ecology》2013,29(6):417-433
The overall effect of the number of boats on the copper (Cu) levels in the water column and sediment, along with their spatial variability within Shelter Island Yacht Basin (SIYB), San Diego Bay, California was examined. We identified a horizontal gradient of increasing dissolved Cu and Cu in sediment from outside to the head of SIYB which was coincident with the increasing number of boats. Spatial models of Cu distribution in water and sediment indicated the presence of ‘hotspots’ of Cu concentration. From outside to the head of SIYB, dissolved Cu ranged from 1.3 μ g L?1 to 14.6 μ g L?1 in surface water, and 2.0 μ g L?1 to 10.2 μ g L?1 in bottom water. Cu in sediment exceeded the Effect Range Low of 34 mg kg?1 (i.e. where adverse effects to fauna may occur), with a peak concentration of 442 mg kg?1 at the head of the basin. Free Cu++ in surface water was several orders of magnitude higher than in sediment porewater. High-resolution data of Cu species together with probability maps presented in this paper will allow managers to easily visualise and localise areas of impaired quality and to prioritise which areas should be targeted to improve Cu-related conditions. 相似文献
4.
Preparation of a porous clay heterostructure and study of its adsorption capacity of phenol and chlorinated phenols from aqueous solutions. 总被引:1,自引:0,他引:1
Sofía Arellano-Cárdenas Tzayhrí Gallardo-Velázquez Guillermo Osorio-Revilla Ma del Socorro López-Cortez 《Water environment research》2008,80(1):60-67
A porous clay heterostructure (PCH) from a Mexican clay was prepared and characterized, and its aqueous phenol and dichlorophenols (DCPs) adsorption capacities were studied using a batch equilibrium technique. The PCH displayed a surface area of 305.5 m2/g, 37.2 A average porous diameter, and a basal space of 23.2 A. The adsorption capacity shown by the PCH for both phenol and DCPs from water (14.5 mg/g for phenol; 48.7 mg/g for 3,4-DCP; and 45.5 mg/g for 2,5-DCP) suggests that the PCH has both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PCH. The values of maximal adsorption capacity for dichlorophenols were higher than those reported for aluminum pillared clays and some inorgano-organo clays and comparable with some ionic exchange resins. 相似文献
5.
A Generic Bio-Economic Farm Model for Environmental and Economic Assessment of Agricultural Systems 总被引:2,自引:0,他引:2
Janssen S Louhichi K Kanellopoulos A Zander P Flichman G Hengsdijk H Meuter E Andersen E Belhouchette H Blanco M Borkowski N Heckelei T Hecker M Li H Oude Lansink A Stokstad G Thorne P van Keulen H van Ittersum MK 《Environmental management》2010,46(6):862-877
Bio-economic farm models are tools to evaluate ex-post or to assess ex-ante the impact of policy and technology change on agriculture, economics and environment. Recently, various BEFMs have been developed, often for one purpose or location, but hardly any of these models are re-used later for other purposes or locations. The Farm System Simulator (FSSIM) provides a generic framework enabling the application of BEFMs under various situations and for different purposes (generating supply response functions and detailed regional or farm type assessments). FSSIM is set up as a component-based framework with components representing farmer objectives, risk, calibration, policies, current activities, alternative activities and different types of activities (e.g., annual and perennial cropping and livestock). The generic nature of FSSIM is evaluated using five criteria by examining its applications. FSSIM has been applied for different climate zones and soil types (criterion 1) and to a range of different farm types (criterion 2) with different specializations, intensities and sizes. In most applications FSSIM has been used to assess the effects of policy changes and in two applications to assess the impact of technological innovations (criterion 3). In the various applications, different data sources, level of detail (e.g., criterion 4) and model configurations have been used. FSSIM has been linked to an economic and several biophysical models (criterion 5). The model is available for applications to other conditions and research issues, and it is open to be further tested and to be extended with new components, indicators or linkages to other models. 相似文献
6.
Guillermo Cabrera Miguel A. Marino 《Journal of the American Water Resources Association》1976,12(2):317-335
ABSTRACT. Transient, two-dimensional solutions are developed which describe the movement and distribution of a conservative substance in a stream-aquifer system. The solutions are obtained by solving sequentially the groundwater flow and mass transport equations. A variational approach in conjunction with the finite element method is used to solve the groundwater flow equation. Galerkin's approach coupled with the finite element method is used to solve the mass transport equation. Linear approximated triangular elements and a centered scheme of numerical integration are employed to calculate the hydraulic head distribution and the concentration of solute in the flow region. The linear approximation used to define the concentration function within each element is not appropriate for cases involving steep concentration gradients. For such cases, higher order approximations are necessary to assure the continuity of gradients across interelemental boundaries. Numerical examples that illustrate the applicability of the model are presented. 相似文献
7.
8.
This paper describes an application of multiple criteria analysis (MCA) in assessing criteria and indicators adapted for a
particular forest management unit. The methods include: ranking, rating, and pairwise comparisons. These methods were used
in a participatory decision-making environment where a team representing various stakeholders and professionals used their
expert opinions and judgements in assessing different criteria and indicators (C&I) on the one hand, and how suitable and
applicable they are to a forest management unit on the other. A forest concession located in Kalimantan, Indonesia, was used
as the site for the case study. Results from the study show that the multicriteria methods are effective tools that can be
used as structured decision aids to evaluate, prioritize, and select sets of C&I for a particular forest management unit.
Ranking and rating approaches can be used as a screening tool to develop an initial list of C&I. Pairwise comparison, on the
other hand, can be used as a finer filter to further reduce the list. In addition to using these three MCA methods, the study
also examines two commonly used group decision-making techniques, the Delphi method and the nominal group technique. Feedback
received from the participants indicates that the methods are transparent, easy to implement, and provide a convenient environment
for participatory decision-making. 相似文献
9.
Ignacio J. Moncho-Esteve Frederik Folke Manuel García-Villalba Guillermo Palau-Salvador 《Environmental Fluid Mechanics》2017,17(4):695-714
This paper presents large eddy simulation of turbulent flow in a meandering open channel with smooth wall and rectangular cross-section. The Reynolds number based on the channel height is 40,000 and the aspect ratio of the cross-section is 4.48. The depth-averaged mean stream-wise velocity agree well to experimental measurements. In this specific case, two interacting cells are formed that swap from one bend to the other. Transport and mixing of a pollutant is analysed using three different positions of release, e.g. on the inner bank, on the outer bank and on the centre of the cross section. The obtained depth-average mean concentration profiles are reasonably consistent with available experimental data. The role of the secondary motions in the mixing processes is the main focus of the discussion. It is found that the mixing when the scalar is released on the centre of the cross-section is stronger and faster than the mixing of the scalar released on the sides. When the position of release is close to a bank side, the mixing is weaker and a clear concentration of scalar close to the corresponding side-wall can be observed in both cases. 相似文献
10.
Environmental niche models (ENMs) have gained enormous popularity as tools to investigate potential changes in species distributions resulting from climate change and species introductions. Despite recognition that species interactions can influence the dynamics of invasion spread, most implementations of ENMs focus on abiotic factors as the sole predictors of potential range limits. Implicit in this approach is the assumption that biotic interactions are relatively unimportant, either because of scaling issues, or because fundamental and realized niches are equivalent in a species' native range. When species are introduced into exotic landscapes, changes in biotic interactions relative to the native range can lead to occupation of different regions of niche space and apparent shifts in physiological tolerances. We use an escaped biological control organism, Cactoblastis cactorum (Berg.), to assess the role of the environmental envelope as compared with patterns of host-herbivore associations based on collections made in the native range. Because all nonnative populations are derived from a single C. cactorum ecotype, we hypothesize that biotic interactions associated with this ecotype are driving the species' invasion dynamics. Environmental niche models constructed from known native populations perform poorly in predicting nonnative distributions of this species, except where there is an overlap in niche space. In contrast, genetic isolation in the native range is concordant with the observed pattern of host use, and strong host association has been noted in nonnative landscapes. Our results support the hypothesis that the apparent shift in niche space from the native to the exotic ranges results from a shift in biotic interactions, and demonstrate the importance of considering biotic interactions in assessing the risk of future spread for species whose native range is highly constrained by biotic interactions. 相似文献