全文获取类型
收费全文 | 1441篇 |
免费 | 100篇 |
国内免费 | 191篇 |
专业分类
安全科学 | 184篇 |
废物处理 | 20篇 |
环保管理 | 279篇 |
综合类 | 567篇 |
基础理论 | 317篇 |
环境理论 | 2篇 |
污染及防治 | 91篇 |
评价与监测 | 76篇 |
社会与环境 | 135篇 |
灾害及防治 | 61篇 |
出版年
2024年 | 2篇 |
2023年 | 18篇 |
2022年 | 43篇 |
2021年 | 39篇 |
2020年 | 56篇 |
2019年 | 42篇 |
2018年 | 33篇 |
2017年 | 63篇 |
2016年 | 75篇 |
2015年 | 68篇 |
2014年 | 62篇 |
2013年 | 98篇 |
2012年 | 109篇 |
2011年 | 112篇 |
2010年 | 78篇 |
2009年 | 109篇 |
2008年 | 66篇 |
2007年 | 90篇 |
2006年 | 72篇 |
2005年 | 61篇 |
2004年 | 66篇 |
2003年 | 49篇 |
2002年 | 45篇 |
2001年 | 35篇 |
2000年 | 19篇 |
1999年 | 29篇 |
1998年 | 30篇 |
1997年 | 19篇 |
1996年 | 11篇 |
1995年 | 14篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 10篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 4篇 |
1986年 | 1篇 |
1985年 | 32篇 |
1984年 | 14篇 |
1983年 | 11篇 |
1982年 | 6篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 2篇 |
1977年 | 1篇 |
1971年 | 2篇 |
排序方式: 共有1732条查询结果,搜索用时 31 毫秒
761.
We study how the distribution of income among members of society, and income inequality in particular, affects social willingness to pay (WTP) for environmental public goods. We find that social WTP for environmental goods decreases (increases) with income inequality if and only if environmental goods and manufactured goods are substitutes (complements). We derive adjustment factors for benefit transfer to control for differences in income distributions between a study site and a policy site. For illustration, we quantify how social WTP for environmental public goods depends on the respective income distributions for empirical case studies in Sweden and the World at large. We find that the adjustment for income inequality can be substantial. 相似文献
762.
S. M. Sayedur Rahman Abdullahil Azeem 《International Journal of Sustainable Engineering》2017,10(2):99-104
Solid waste disposal poses a significant problem, as it leads to land pollution if openly dumped, water pollution if dumped in low lands and air pollution if burnt. Moreover, the scarcity of land and increase in land prices especially in Dhaka, the capital city of Bangladesh create the problems of developing new landfill sites. Realising the existing and future impacts of waste disposal issues, the analytic hierarchy process model was applied to select an appropriate Waste-to-Energy (WTE) conversion technology for household waste of Dhaka-Mirpur Cantonment area. Three alternatives, namely, anaerobic digestion, pyrolysis and plasma gasification (PG) technologies and nine criteria under three aspects (technological, environmental and financial) were chosen for comparison. The analysis revealed that PG is the most appropriate WTE conversion technology in the study area. The selected PG technology has a relatively small footprint; it can treat unsorted waste and can produce good-quality synthetic gas without generating extremely toxic by-products. 相似文献
763.
A Standard Lexicon for Biodiversity Conservation: Unified Classifications of Threats and Actions 总被引:3,自引:0,他引:3
NICK SALAFSKY††† DANIEL SALZER† ALISON J. STATTERSFIELD‡ CRAIG HILTON-TAYLOR§ RACHEL NEUGARTEN† STUART H. M. BUTCHART‡ BEN COLLEN NEIL COX†† LAWRENCE L. MASTER‡‡ SHEILA O'CONNOR§§ DAVID WILKIE 《Conservation biology》2008,22(4):897-911
Abstract: An essential foundation of any science is a standard lexicon. Any given conservation project can be described in terms of the biodiversity targets, direct threats, contributing factors at the project site, and the conservation actions that the project team is employing to change the situation. These common elements can be linked in a causal chain, which represents a theory of change about how the conservation actions are intended to bring about desired project outcomes. If project teams want to describe and share their work and learn from one another, they need a standard and precise lexicon to specifically describe each node along this chain. To date, there have been several independent efforts to develop standard classifications for the direct threats that affect biodiversity and the conservation actions required to counteract these threats. Recognizing that it is far more effective to have only one accepted global scheme, we merged these separate efforts into unified classifications of threats and actions, which we present here. Each classification is a hierarchical listing of terms and associated definitions. The classifications are comprehensive and exclusive at the upper levels of the hierarchy, expandable at the lower levels, and simple, consistent, and scalable at all levels. We tested these classifications by applying them post hoc to 1191 threatened bird species and 737 conservation projects. Almost all threats and actions could be assigned to the new classification systems, save for some cases lacking detailed information. Furthermore, the new classification systems provided an improved way of analyzing and comparing information across projects when compared with earlier systems. We believe that widespread adoption of these classifications will help practitioners more systematically identify threats and appropriate actions, managers to more efficiently set priorities and allocate resources, and most important, facilitate cross‐project learning and the development of a systematic science of conservation. 相似文献
764.
Few economic studies are available to measure off-highway vehicle recreation benefits foregone when trails must be closed to protect the environment. This paper estimates the non-market benefits associated with off-highway vehicle (OHV) recreation on National Forest lands in Larimer County, Colorado. We use a contingent valuation model (CVM) to estimate benefits to OHV users, which includes dirt bike riders, all terrain vehicle (ATV) riders, and 4-wheel drive (4 × 4) users. Using CVM we find the mean consumer surplus estimates to be $78 per person per day. These results are consistent with the few previous estimates of OHV recreation benefits. This equates to a per trail per summer consumer surplus of at least between $219,467 and $296,876, and a county level surplus per summer to be at least between $796,447 and $1,077,367. These benefits can be compared to environmental costs to obtain a more complete picture of the effects of trail closure, as well as the negative spillovers to non-motorized users. 相似文献
765.
For matrix population models, analyses of how sensitive the population growth rate is to changes in vital rates (i.e. perturbations) are important for studies of life history evolution as well as for management and conservation of threatened species. There are two types of sensitivity analyses corresponding to absolute (sensitivity) or relative (elasticity) changes in the vital rates and both types can be applied to both deterministic and stochastic matrix population models. To date, most empirical studies of elasticity and sensitivity of the stochastic growth rate have examined the response to perturbations in the vital rates in a complete set of possible environments. However, it is often of interest to examine the response to perturbations occurring in only a subset of the possible environments. This has been done for periodic time-varying models elsewhere, but here we describe a recently published method for calculating the environment-specific sensitivity and elasticity of the stochastic growth rate and apply this method to data. These environment-specific perturbation analyses provide a logical way of dividing the sensitivity and elasticity among the environments. They give important insight into the selection regime in different environments and can provide valuable information for making management decisions and management evaluations in stochastic environments. 相似文献
766.
以齐齐哈尔市城区声环境质量监测为依据,探讨了城区产生环境噪声污染的主要原因,分析了环境噪声污染现状,制定了相应的防治对策。 相似文献
767.
Modelling the responses of wildlife to human disturbance: An evaluation of alternative management scenarios for black-crowned night-herons 总被引:1,自引:0,他引:1
Victoria J. Bennett Esteban Fernández-JuricicPatrick A. Zollner Matthew J. BeardLynne Westphal Cherie L. LeBlanc Fisher 《Ecological modelling》2011,222(15):2770-2779
The impact of anthropogenic disturbance on wildlife is increasing becoming a source of concern as the popularity of outdoor recreation rises. There is now more pressure on site managers to simultaneously ensure the continued persistence of wildlife and provide recreational opportunities. Using ‘Simulation of Disturbance Activities’, a model designed to investigate the impact of recreational disturbance on wildlife, we demonstrate how a simulation modelling approach can effectively inform such management decisions. As an example, we explored the implications of various design and management options for a proposed recreational area containing a historic breeding bird colony. By manipulating the proximity, orientation and intensity of recreation, we were able to evaluate the impact of recreational activities on the behaviour of black-crowned night-heron nestlings (Nycticorax nycticorax). Using a classification and regression tree (CART) procedure to analyse simulation output, we explored the dynamics of multiple strategies in concert. Our analysis revealed that there are inherent advantages in implementing multiple strategies as opposed to any single strategy. Nestlings were not disturbed by recreation when bird-watching facility placement (proximity and orientation) and type were considered in combination. In comparison, proximity alone only led to a <10% reduction in disturbance. Thus we demonstrate how simulation models based on customised empirical data can bridge the gap between field studies and active management, enabling users to test novel management scenarios that are otherwise logistically difficult. Furthermore, such models potentially have broad application in understanding human-wildlife interactions (e.g. exploring the implications of roads on wildlife, probability of bird strikes around airports, etc.). They therefore represent a valuable decision-making tool in the ecological design of urban infrastructures. 相似文献
768.
In recent years, evaluating the robustness of environmental models results has become essential in order to effectively support decision makers to define suitable emission control strategies. This evaluation is performed in literature through uncertainty and sensitivity analyses. Therefore, the application of such methodologies to air quality Integrated Assessment Models (IAMs) is extremely challenging. In fact, in this case uncertainty and sensitivity analyses should be assessed not only for each single component of the system, but also for the overall IAM. In the paper, an attempt is made to extend and systematize the information available on uncertainty/sensitivity analysis, at first considering environmental models in general, and then focusing on air quality IAMs. The study aims to offer a tentative framework addressed to modelers and decision makers in the implementation of IAM and evaluation of its results. The framework has been tested on Lombardy region (Northern Italy). The results show how the uncertainty on Drivers of emissions propagates on the whole modelling chain characterizing an integrated assessment study. 相似文献
769.
770.
Introduction: Providing a sense of supervision for parents may facilitate their children’s involvement in physical outdoor activities, such as walking to school. Information technology (IT) solutions could bring more parental supervision, which in turn has the potential to enhance the proportion of walking trips to school. This study aimed to examine the role of a proposed hypothetical IT solution that gives parents real-time information about children’s entrance to and exit from the school, for the intention of parents letting their children walk to school. Method: A total of 820 questionnaires were distributed among pupils aged 7–9-years across 28 elementary schools to be completed by their parents (82% return rate). Results: Compared to the group of walking pupils, increased parental intention to let their children walk to school under the proposed solution could be explained by considerably more variables in the group of pupils who did not walk to school. The findings revealed that increased parental intention was higher among the walking pupils compared to the non-walking pupils. For the non-walking pupils, enhancement of walking facilities across the school area could potentiate the use of the proposed solution by the parents, which in turn may increase the proportion of walking on school trips. In addition, boy pupils, the pupils whose parents evaluated walking more favorable, those from lower socioeconomic backgrounds, and those living in close proximity to the school could more likely benefit by shifting from non-walking to walking modes of travel, after implementation of the solution. 相似文献