全文获取类型
收费全文 | 633篇 |
免费 | 24篇 |
国内免费 | 42篇 |
专业分类
安全科学 | 75篇 |
废物处理 | 4篇 |
环保管理 | 188篇 |
综合类 | 166篇 |
基础理论 | 102篇 |
污染及防治 | 31篇 |
评价与监测 | 65篇 |
社会与环境 | 55篇 |
灾害及防治 | 13篇 |
出版年
2023年 | 7篇 |
2022年 | 10篇 |
2021年 | 15篇 |
2020年 | 23篇 |
2019年 | 15篇 |
2018年 | 10篇 |
2017年 | 15篇 |
2016年 | 24篇 |
2015年 | 24篇 |
2014年 | 28篇 |
2013年 | 69篇 |
2012年 | 27篇 |
2011年 | 51篇 |
2010年 | 23篇 |
2009年 | 42篇 |
2008年 | 33篇 |
2007年 | 57篇 |
2006年 | 27篇 |
2005年 | 28篇 |
2004年 | 25篇 |
2003年 | 26篇 |
2002年 | 20篇 |
2001年 | 21篇 |
2000年 | 23篇 |
1999年 | 12篇 |
1998年 | 5篇 |
1997年 | 9篇 |
1996年 | 2篇 |
1995年 | 5篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 2篇 |
1982年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有699条查询结果,搜索用时 22 毫秒
151.
Environmental, biological, socio-cultural and economic variations in the Himalayas have led to the evolution of diverse and unique traditional agroecosystems, crop species, and livestock, which help the traditional mountain farming societies to sustain themselves. During the recent past, as a result of rapid changes in land use caused by socio-cultural and economic changes and various environmental perturbations, the agrobiodiversity of the Central Himalayan agroecosystems has changed steadily. A recent survey conducted in 150 different villages located along an elevated transect of the Alaknanda catchment of the Central Himalaya revealed that over a period of two decades (1970–74 and 1990–94) the cultivated area under many traditional crops had declined significantly. A micro-level study carried out in 30 villages revealed that a series of changes had occurred in land use practices over a period of 25–30 years.The loss of agrobiodiversity and the changing socio-cultural and economic dimensions and their impacts on the sustainability of Himalayan agroecosystems are emerging as major causes of concern at local/regional/national scale, and appropriate options to meet these challenges are discussed in this paper. 相似文献
152.
Problem: Safety management literature generally categorizes key performance indicators (KPIs) as either leading or lagging. Traditional lagging indicators are measures related to negative safety incidents, such as injuries, while leading indicators are used to predict (and therefore can be used to prevent) the likelihood of future negative safety incidents. Recent theory suggests that traditional lagging indicators also possess characteristics of leading indicators, and vice versa, however empirical evidence is limited. Method: The current research investigated the temporal relationships among establishment-level injuries, near misses, and fatal events using injury and employment data from a sample of 24,910 mining establishments over a 12-year period. Results: While controlling for employee hours worked, establishment-level reported injuries and near misses were associated with of future fatal events across the sample of mines and over the time period studied. Fatal events were also associated with increases in future reported near misses, providing evidence of a cyclic relationship between them. Discussion: These findings challenge the strict categorization of injuries, near misses, and fatal events as lagging indicators. Practical applications: Understanding the KPIs that should be used to manage organizational safety, and how they can be used, is of critical practical importance. The results of the current study suggest that, depending on several considerations, metrics tied to negative safety incidents may be used to anticipate, and possibly prevent, future negative safety events. 相似文献
153.
Athanailidis V. Ilias Rentoumis G. Meletios Bilalis Nikolaos 《International Journal of Sustainable Engineering》2018,11(3):186-195
Photovoltaic (PV) energy generation devices have experienced a vigorous growth in production over the last decade in all major industrialised countries. In this research paper, the assessment of recycling and subsequent production of new crystalline silicon (c-Si) PV modules taking advantage of the recovered Si in terms of industrial symbiosis is being examined. With the aid of life cycle analysis method, the potential payback is thoroughly examined through a scenario application in the second useful phase of the PV module. Furthermore, key environmental performance indicators have been implemented in order to evaluate power and resource demands. 相似文献
154.
The feasibility of using a chemical reaction-based approach for evaluating and modelling the role of adsorption reactions in determining the geochernical confinement capacity of natural geological barriers is being studied as part of an on-going R & D programme. The confined superficial aquifer underlying the Centre de Stockage de l'Aube facility, a geological barrier for this site, has been used as a case study with the following aims. First, development of a site characterisation protocol and demonstration of its use to determine the principal geochemical characteristics of aquifer materials using batch experiments and to represent the information obtained in terms of a chemical model. The experimental results obtained for Ni2+ partitioning as a function of total Ni, pH, total Ca and total solid can be satisfactorily represented in terms of reactions with an ion exchange site and a single amphoteric surface hydroxyl site with ferrihydrite reaction constants. A second objective is the incorporation of the reactions in a coupled geochemistry/transport code, and to verify the applicability of the coupled code predictions for Ni2+ mass transfer by comparison with the results obtained during column tracer experiments. The breakthrough curve and equilibrium solid phase Ni loading, predicted by a one-dimensional coupled model for a column tracer experiment, agree closely with observed data.Additional studies are underway to reduce model conditionality, to extend the adsorption model to other analogue cations and anions, to incorporate the effect of natural organic matter and to take into consideration precipitation/dissolution of amorphous Fe surface phases. 相似文献
155.
Estuaries and coastal lagoons are characterized by a strong spatial and temporal variability of physicochemical characteristics and productivity patterns. In these environments, the magnitude and direction of the ecological responses to inorganic nutrient increase (i.e. eutrophication) are difficult to predict. In the framework of the project, New Indicators of Trophic state and environmental quality of marine coastal ecosystems and transitional environments (NITIDA), we analysed benthic indicators of trophic state, ecosystem efficiency, and environmental quality in four different transitional environments. The trophic state of the sediments was assessed in terms of quantity and bioavailability of sediment organic C pools; ecosystem efficiency was determined in terms of the prokaryote efficiency in exploiting enzymatycally degraded organic C; environmental quality was determined in terms of meiofaunal diversity. Here, we provide a synopsis of the results obtained and a meta-analysis of the scores assessments obtained using the different ecological indicators of environmental quality and demonstrate that trophic state, ecosystem efficiency, and biodiversity in transitional ecosystems are closely linked. We conclude that the assessment of the environmental quality of transitional ecosystems should be based upon a battery of trophic state indicators and 'sensors' of ecosystem functioning, efficiency, and quality. 相似文献
156.
选取某油气田企业为试点,从本质安全的角度确立了一套过程安全管理绩效指标。过程安全绩效指标包括质量、设备、安全、环保参数及生产平稳率、设备完整性等考核要素。运用于原油和天然气的生产处理全过程,形成了在油气田生产行业应用的安全管理模式和管理方法。 相似文献
157.
环境管理指标系统之建立与选择 总被引:2,自引:0,他引:2
介绍环境绩效评估发展的缘起及其发展趋势,叙述环境管理指标系统之间内涵与建立的步骤以及各类型环境绩效指标的种类及其稳定原则。 相似文献
158.
中国土地可持续利用指标体系的理论与方法 总被引:157,自引:7,他引:157
制定土地资源可持续性指标体系是《21世纪议程》中对各国提出的科学技术优先研究领域 ,国土资源部已开始了该研究项目。论文就此对中国土地资源可持续利用指标体系的理论与方法从整体上进行了探讨。首先回顾了国内外土地可持续利用研究的进展 ,分析归纳了国外可持续发展指标体系研究状况及可借鉴之处 ;指出在土地可持续利用指标与评价的研究中 ,必须从3个方面开展深入探讨。第一是土地利用分区及制定区域性土地可持续利用指标体系 ;第二是研究制定主要土地利用系统可持续利用指标体系及其阈值 ;第三是研究制定典型区域(以县域为单位)土地可持续利用指标体系及其阈值。只有把3个方面的研究有机融合起来 ,互相反馈 ,互为依存 ,才能保证土地可持续利用指标体系的科学性、系统性和实用性。 相似文献
159.
160.
Monitoring of Biological Diversity: a Common-Ground Approach 总被引:4,自引:0,他引:4
TIIT TEDER† MARI MOORA† ELLE ROOSALUSTE† KRISTJAN ZOBEL† MEELIS PÄRTEL† URMAS KÕLJALG† MARTIN ZOBEL† 《Conservation biology》2007,21(2):313-317
Abstract: Practical approaches to monitoring biological diversity vary widely among countries, and the accumulating data are frequently not generalizable at the international scale. Although many present monitoring schemes, especially in developed countries, produce highly complex data, there is often a lack of basic data about the level and spatial distribution of biodiversity. We augmented the general framework for improving biomonitoring, proposed by Green et al. (2005) , and identified its core tasks and attributes. The first priority for a more unified biodiversity monitoring is to agree on a minimum set of core tasks and attributes, which will make it possible to build a standardized biomonitoring system even in countries with few resources. Our scheme has two main organizational levels—taxa and ecosystems. The basic elements of the biomonitoring system proposed are recording of presence and absence of taxa and ecosystems in a target area, mapping of their distribution in space, and assessment of their status. All the elements have to be repeated over time. Although these tasks are fundamental, they are frequently not considered in currently functioning biomonitoring programs. The whole system has to be hierarchical and additive: if more resources are available, new activities may be added to the basic routine. Agreeing on a common standard will facilitate aggregating measures of biodiversity status and trends into regional and global indices. This information will relate directly to several Convention on Biological Diversity indicators for assessing progress toward the 2010 Biodiversity Target. 相似文献