全文获取类型
收费全文 | 3492篇 |
免费 | 15篇 |
国内免费 | 39篇 |
专业分类
安全科学 | 69篇 |
废物处理 | 162篇 |
环保管理 | 343篇 |
综合类 | 592篇 |
基础理论 | 1229篇 |
环境理论 | 3篇 |
污染及防治 | 707篇 |
评价与监测 | 232篇 |
社会与环境 | 206篇 |
灾害及防治 | 3篇 |
出版年
2022年 | 9篇 |
2021年 | 22篇 |
2020年 | 9篇 |
2019年 | 13篇 |
2018年 | 131篇 |
2017年 | 140篇 |
2016年 | 209篇 |
2015年 | 68篇 |
2014年 | 41篇 |
2013年 | 63篇 |
2012年 | 455篇 |
2011年 | 248篇 |
2010年 | 59篇 |
2009年 | 59篇 |
2008年 | 66篇 |
2007年 | 82篇 |
2006年 | 88篇 |
2005年 | 404篇 |
2004年 | 542篇 |
2003年 | 415篇 |
2002年 | 53篇 |
2001年 | 45篇 |
2000年 | 28篇 |
1999年 | 42篇 |
1998年 | 11篇 |
1997年 | 12篇 |
1996年 | 6篇 |
1995年 | 12篇 |
1994年 | 9篇 |
1991年 | 10篇 |
1990年 | 6篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1985年 | 7篇 |
1967年 | 7篇 |
1966年 | 4篇 |
1965年 | 6篇 |
1964年 | 7篇 |
1962年 | 7篇 |
1961年 | 4篇 |
1960年 | 5篇 |
1958年 | 4篇 |
1957年 | 4篇 |
1956年 | 4篇 |
1954年 | 7篇 |
1952年 | 4篇 |
1942年 | 4篇 |
1939年 | 5篇 |
1931年 | 4篇 |
排序方式: 共有3546条查询结果,搜索用时 15 毫秒
91.
92.
Morselli L Luzi J De Robertis C Vassura I Carrillo V Passarini F 《Waste management (New York, N.Y.)》2007,27(8):S85-S91
In Emilia-Romagna region (Northern Italy) the integrated waste treatment system consists of material collection and recycling, incineration with energy recovery and landfill as final disposal. In particular, at least one incineration plant is working in almost every province of the region. In this work, a screening life cycle assessment approach is applied to seven different incinerators, to compare the different plant technologies and identify the most relevant environmental impacts and processes. The characterization method used in the life cycle impact assessment step is Eco-indicator 99. The functional unit is 1 ton of waste input. As a first result, it can be noted that while the combustion systems are rather similar, the main variables are ascribable to gas cleaning options and efficiency in energy recovery, which result in quite different environmental performances. Among heavy metals, particular attention must be paid to Cd and As, due to their high toxicity, despite their low quantities. The impact due to dioxin emission is orders of magnitude lower than other contaminants (e.g., heavy metals). Furthermore, a catalytic system could be useful for a complete removal of organic contaminants and for a more effective abatement of nitrogen oxides. Finally, the environmental impact assessment sorts the various plants according to their age, i.e., the most recent plants provide the best environmental performances for the same quantity of combusted waste. 相似文献
93.
Accumulation and partitioning of heavy metals in mangroves: a synthesis of field-based studies 总被引:6,自引:0,他引:6
We report the findings of a comparative analysis examining patterns of accumulation and partitioning of the heavy metals copper (Cu), lead (Pb) and zinc (Zn) in mangroves from available field-based studies to date, employing both species level analyses and a phylogenetic approach. Despite mangroves being a taxonomically diverse group, metal accumulation and partitioning for all metals examined were broadly similar across genera and families. Patterns of metal accumulation were also similar regardless of whether species were classified as salt secreting or non-secreting. Metals were accumulated in roots to concentrations similar to those of adjacent sediments with root bio-concentration factors (BCF; ratio of root metal to sediment metal concentration) of 1< or =. Root BCFs were constant across the exposure range for all metals. Metal concentrations in leaves were half that of roots or lower. Essential metals (Cu and Zn; translocation factors (TF; ratio of leaf metal to root metal concentration) of 0.52 and 0.53, and leaf BCFs of 0.47 and 0.51, respectively) showed greater mobility than non-essential metals (Pb; TF of 0.31 and leaf BCF of 0.11). Leaf BCFs for the essential metals Cu and Zn decreased as environmental concentrations increased. The non-essential metal Pb was excluded from leaf tissue regardless of environmental concentrations. Thus mangroves as a group tend to operate as excluder species for non-essential metals and regulators of essential metals. For phytoremediation initiatives, mangrove ecosystems are perhaps best employed as phytostabilisers, potentially aiding in the retention of toxic metals and thereby reducing transport to adjacent estuarine and marine systems. 相似文献
94.
The capacity of the Australian native fern Pteris umbrosa to function as an arsenic (As) hyperaccumulator (shoot:soil As concentration >1) was examined by growing plants under glasshouse conditions in an inert medium supplemented with As. Arsenic preferentially accumulated in the fronds, a trait of a hyperaccumulator. The As concentration of fronds decreased with age, being particularly high in the croziers and low in the senesced fronds. Below ground, rhizomes accumulated more As than adventitious roots. Uptake from a range of solution concentrations followed Michaelis Menten kinetics up to a soil solution As concentration of 400mgl(-1). The K(m) for As uptake by roots suggested the operation of a low-affinity carrier. The predicted Nernst membrane potential indicated that uptake was against the electrochemical gradient of As. At 600mgl(-1), the rate of As uptake increased and phytotoxic effects were indicated by a significant decline in biomass. Arsenic uptake and translocation in P. umbrosa and Pteris vittata were similar at low exposure to As. At higher exposure, As uptake and translocation by P. vittata increased more than in P. umbrosa. The growth rate of both ferns was similar, whereas the biomass distribution was not, with P. vittata having a much larger root mass. This suggests that As uptake by P. umbrosa roots was very efficient and may be improved by stimulating root growth to enhance its potential. 相似文献
95.
96.
The theory of space accessibility analysis, space syntax, has been considered for capturing trip-makers’ route-choice decisions with an understanding that, while selecting routes, trip-makers tend to follow forward-facing fields traditionally represented by axial lines. But the idea of treating axial lines as a set of roadway segments representing an urban texture has remained under scrutiny when distinct procedures have been tested without much success. Nor has the axial-line theory seemed to gain much popularity within the orthodox transportation planning community. Studies show that a long axial line is found gaining configurational centrality, in general, for being well connected to its incident lines. Fragmenting a long axial line results in weakening it (in centrality terms), but also in generating a locally oriented model. Recent investigations, dealing with this problem, have resulted in the emergence of the unit-segment theory, which has turned out to be more sensitive to the local structures located within a large urban texture than the axial counterpart for the purpose of modeling vehicular movement networks without using origin–destination trip-counts. Essentially, the question now is: Is the unit-segment analysis also capable of generating syntax configurations that are equally sensitive to large and complex urban textures? What should be the methodology of such an analysis? This paper throws deeper insights into these questions by producing theoretical and empirical research findings and seeks to develop a common ground for both transportation planning and space syntax communities to work together for gaining a better understanding of how urban configurations relate to urban vehicular movement networks. 相似文献
97.
Kishore?Kumar?MahatoEmail author Krishna?Dutta Bankim?Chandra?Ray 《Journal of Polymers and the Environment》2018,26(3):1024-1050
The study of static and dynamic behavior of environmentally conditioned fibre reinforced polymeric (FRP) composites is necessary and crucial to examine the durability, reliability and sustainability of these noble materials. FRP composites are being used all around the globe and substituting the conventional materials, starting from mini toys to large aerospace components. Present review has introduced to accumulate and understand the disseminate literature in concentrating the significance of understanding the static and dynamic behavior of FRPs with changing environmental conditionings (hygrothermal, low and high temperature, salt solution, freeze thaw, UV light) and with the interaction of different nano-fillers. Their stability and integrity in diverse service environments may be reformed by their reactions against different nature of loadings i.e. static or dynamic and the components such as fibre, matrix and fibre/matrix interfaces in those environments. The static and dynamic states of loading may come with a possible weaker region to encounter the durability and integrity of the composites. To understand the exact failure modes that correlates the position of environmentally conditioned interfaces and dynamic state of loadings, thus confusing the estimation of its overall performance and mechanical behavior. Interface reliability and durability is vital since in-service environments the degradation in the interfacial region leads to complete composite failure. Therefore, the study of combined effects of various in-service environmental conditions and the role of static and dynamic behavior on the interface will be a crucial part related to the multiaxial dynamic states of failures occurring in FRP’s. 相似文献
98.
Anke Fischer Wouter Spekkink Christine Polzin Alberto Díaz-Ayude Ambra Brizi Irina Macsinga 《环境政策》2018,27(4):621-643
There is a substantial body of literature on public understandings of large-scale ‘environmental’ phenomena such as climate change and resource degradation. At the same time, political science and economics analyse the governance arrangements to deal with such issues. These realms of research rarely meet: there has been little research into people’s understandings of the governance of environmental change. This study adds a psychological perspective to governance research by investigating social representations of governance that promotes societal change towards sustainability, and related practices. It examines data from qualitative interviews with sustainability-interested people in seven European countries (n = 105). The analysis identified building blocks of representations suitable as an analytical framework for future research on governance representations. The diversity of their content reflected a range of pathways to societal change. Representations often seemed to have a creative function as a guiding vision for individuals’ own practices, but their wider transformative potential was constrained. 相似文献
99.
The farmer as a landscape steward: Comparing local understandings of landscape stewardship,landscape values,and land management actions 总被引:1,自引:0,他引:1
Christopher M. Raymond Claudia Bieling Nora Fagerholm Berta Martin-Lopez Tobias Plieninger 《Ambio》2016,45(2):173-184
We develop a landscape stewardship classification which distinguishes between farmers’ understanding of landscape stewardship, their landscape values, and land management actions. Forty semi-structured interviews were conducted with small-holder (<5 acres), medium-holders (5–100 acres), and large-holders (>100 acres) in South-West Devon, UK. Thematic analysis revealed four types of stewardship understandings: (1) an environmental frame which emphasized the farmers’ role in conserving or restoring wildlife; (2) a primary production frame which emphasized the farmers’ role in taking care of primary production assets; (3) a holistic frame focusing on farmers’ role as a conservationist, primary producer, and manager of a range of landscape values, and; (4) an instrumental frame focusing on the financial benefits associated with compliance with agri-environmental schemes. We compare the landscape values and land management actions that emerged across stewardship types, and discuss the global implications of the landscape stewardship classification for the engagement of farmers in landscape management. 相似文献
100.
Marlene Roellig Laura M. E. Sutcliffe Marek Sammul Henrik von Wehrden Jens Newig Joern Fischer 《Ambio》2016,45(2):185-195
Wood-pastures are associated with high cultural and biodiversity values in Europe. However, due to their relatively low productivity, large areas of wood-pastures have been lost over the last century. In some areas, incentive schemes have been developed to revive wood-pastures. We investigated the effects of one such scheme in western Estonia. We compared the structure of grazed wood-pastures (old and restored) to those of abandoned wood-pastures and ungrazed forest stands to explore the effects of management, and conducted interviews with 24 farmers to investigate their motivations to carry out the management. We found a positive influence of active management on the semi-open structure of wood-pastures. Financial support was vital for management, but personal values related to tradition also played an important role. The interviewees differed widely in their range of motivations, suggesting that other strategies in addition to financial incentives would further improve the management of wood-pastures in the region.