全文获取类型
收费全文 | 294篇 |
免费 | 4篇 |
国内免费 | 4篇 |
专业分类
安全科学 | 27篇 |
废物处理 | 2篇 |
环保管理 | 90篇 |
综合类 | 33篇 |
基础理论 | 63篇 |
污染及防治 | 52篇 |
评价与监测 | 18篇 |
社会与环境 | 16篇 |
灾害及防治 | 1篇 |
出版年
2021年 | 1篇 |
2019年 | 3篇 |
2018年 | 13篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 5篇 |
2014年 | 8篇 |
2013年 | 19篇 |
2012年 | 7篇 |
2011年 | 9篇 |
2010年 | 14篇 |
2009年 | 9篇 |
2008年 | 15篇 |
2007年 | 16篇 |
2006年 | 20篇 |
2005年 | 17篇 |
2004年 | 14篇 |
2003年 | 8篇 |
2002年 | 18篇 |
2001年 | 5篇 |
2000年 | 2篇 |
1999年 | 6篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 5篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有302条查询结果,搜索用时 17 毫秒
1.
Márcia Maria Guedes Alcoforado de Moraes Anne Biewald Ana Cristina Guimarães Carneiro Gerald Norbert Souza da Silva Alexander Popp Hermann Lotze-Campen 《Regional Environmental Change》2018,18(7):1943-1955
Economic values of water for the main Public Irrigation Schemes in the sub-middle region of the São Francisco River Basin, in northeastern Brazil, are determined in this study using an integration of a global agro-economic land and water use (MAgPIE) with a local economic model (Positive Mathematical Programming). As in the latter, the water values depend on the crops grown, and as Brazilian agriculture is strongly influenced by the global market, we used a regionalized version of the global model adapted to the region in order to simulate the crop land use, which is in turn determined by changes in global demand, trade barriers, and climate. The allocation of sugarcane and fruit crops projected with climate change by the global model, showed an impact on the average yields and on the water costs in the main schemes resulting in changes in the water values locally. The economic values for all schemes in the baseline year were higher than the water prices established for agricultural use in the basin. In the future, these water values will be higher in all the schemes. The highest water values currently and in the future were identified in municipalities with a significant proportion of area growing irrigated sugarcane. Being aware of current water values of each user in a baseline year and in a projected future under global climate and socioeconomic changes, decision makers should improve water allocation policies at local scale, in order to avoid conflicts and unsustainable development in the future. 相似文献
2.
Michael Duijn Arwin van Buuren Magnus Sparrevik Adriaan Slob Gerald Jan Ellen Amy Oen 《Journal of Environmental Planning and Management》2016,59(5):927-947
This study aims at describing, analyzing and evaluating the relation between management styles and process dynamics of a complex planning process confronted with unexpected dynamics. The development of an aquatic disposal site for dredged contaminated sediments in Oslo was managed by a project management style focused on timely and cost-effective implementation. Coupling the remediation project with another infrastructural project and the actual construction of the site led to unexpected dynamics in terms of resistance and controversy. Project management had difficulties in adjusting its style accordingly, resulting in even more delay and resistance. Managing complex planning projects requires a style suitable to the characteristics of the project and the capability of adjusting it to changing circumstances. The paper concludes with some explanations why it is difficult to change management styles in complex planning and implementation processes and complexity-embracing approaches to deal with this. 相似文献
3.
4.
Patrick Hitayezu Edilegnaw Wale Gerald F. Ortmann 《Environment, Development and Sustainability》2016,18(4):985-1003
On-farm tree cultivation is considered an important strategy to mitigate detrimental environmental impacts of agricultural land-use change (ALUC). In South Africa, however, little is known about farm-level incentives and constraints that govern ALUC decisions among small-scale farmers. To address this knowledge gap, this study employs a mixed multinomial logit model by using a combination of revealed and stated preference data. After correcting for endogeneity, the estimated results show that decisions about ALUC are rationally derived and driven by clear but heterogeneous preferences and trade-offs between crop productivity, food security and labour saving. The results further show that the decision to plant sugarcane is constrained by landholding, whilst farmland afforestation is negatively influenced by household size. Decisions to convert land use are also driven by the behaviour of peer groups and agro-ecological conditions. Based on these findings, important policy implications for sustainable land use are outlined. 相似文献
5.
Gerald J. Kauffman Andrew R. Homsey Andrew C. Belden Jessica Rittler Sanchez 《Environmental monitoring and assessment》2011,177(1-4):193-225
In 1940, the tidal Delaware River was ??one of the most grossly polluted areas in the United States.?? During the 1950s, water quality was so poor along the river at Philadelphia that zero oxygen levels prevented migration of American shad leading to near extirpation of the species. Since then, water quality in the Delaware Basin has improved with implementation of the 1961 Delaware River Basin Compact and 1970s Federal Clean Water Act Amendments. At 15 gages along the Delaware River and major tributaries between 1980 and 2005, water quality for dissolved oxygen, phosphorus, nitrogen, and sediment improved at 39%, remained constant at 51%, and degraded at 10% of the stations. Since 1980, improved water-quality stations outnumbered degraded stations by a 4 to 1 margin. Water quality remains good in the nontidal river above Trenton and, while improved, remains fair to poor for phosphorus and nitrogen in the tidal estuary near Philadelphia and in the Lehigh and Schuylkill tributaries. Water quality is good in heavily forested watersheds (>50%) and poor in highly cultivated watersheds. Water quality recovery in the Delaware Basin is coincident with implementation of environmental laws enacted in the 1960s and 1970s and is congruent with return of striped bass, shad, blue crab, and bald eagle populations. 相似文献
6.
Shui-Yan Tang Carlos Wing-Hung Lo Gerald E. Fryxell 《Journal of environmental management》2010,91(10):2008-2018
This paper examines how configurations of external support factors have evolved alongside governance reform in recent years and how these evolving configurations have affected regulatory enforcement in four counties in Guangdong Province in China. Based on in-depth interviews with leading officials in the local environmental protection bureaus (EPBs), we show that there have been increases in government and societal support for local EPBs in their regulatory work, thanks partly to a number of recent governance reform efforts, but many problems have remained. Based on a questionnaire survey of enforcement officials, we examine how the perceptions of government and societal support are related to EPB officials’ self-perception of effectiveness. It is found that both local government support and societal support have an influence on enforcement officials’ self-assessment of effectiveness, but the relationships varied considerably depending on various dimensions of effectiveness and the patterns of interactions between government and societal support. 相似文献
7.
Gerald Kirchner Friederike Strebl Peter Bossew Sabine Ehlken Martin H. Gerzabek 《Journal of environmental radioactivity》2009
Literature data on numerical values obtained for the parameters of the two most popular models for simulating the migration of radionuclides in undisturbed soils have been compiled and evaluated statistically. Due to restrictions on the applicability of compartmental models, the convection–dispersion equation and its parameter values should be preferred. For radiocaesium, recommended values are derived for its effective convection velocity and dispersion coefficient. Data deficiencies still exist for radionuclides other than caesium and for soils of non-temperate environments. 相似文献
8.
Z. Gerald Liu Wayne A. Eckerle Nathan A. Ottinger 《Journal of the Air & Waste Management Association (1995)》2013,63(12):1333-1345
ABSTRACTU.S. Tier 4 Final and Euro Stage IV and V regulations for nonroad compression-ignition engines have led to the development of exhaust aftertreatment technologies optimized for nonroad engines and duty cycles. In this study, several aftertreatment configurations consisting of state-of-the-art diesel oxidation catalysts (DOCs), diesel particulate filters (DPFs), copper (Cu) zeolite– and vanadium-based selective catalytic reduction (SCR) catalysts, and ammonia oxidation (AMOX) catalysts are evaluated using both nonroad transient (NRTC) and steady (8-mode NRSC) cycles in order to understand both component- and system-level effects of diesel aftertreatment on gas-phase, semivolatile, and particle-phase and particle-bound unregulated organic emissions. Organic emissions reported in this work include total hydrocarbon (THC), n-alkanes, branched alkanes, saturated cycloalkanes, aromatics, aldehydes, ketones, hopanes, steranes, and soluble organic fraction (SOF). Brake-specific emissions are reported for four configurations, including engine-out, DOC+CuZ-SCR+AMOX, V-SCR+AMOX, and DOC+DPF+CuZ-SCR+AMOX, and conversion of engine-out emissions is reported for the three aftertreatment configurations. Mechanisms responsible for the reduction of organic species are discussed in detail. This summary of emissions from a current nonroad diesel engine equipped with advanced aftertreatment can be used to more accurately model the impact of anthropogenic emissions on the atmosphere with tools such as the U.S. Environmental Protection Agency’s Motor Vehicle Emissions Simulator (MOVES2014a) model.Implications: Anthropogenic emissions are a source of significant human health and environmental risk. This study, focused on the treatment of exhaust emissions from a modern nonroad diesel engine with a variety of aftertreatment configurations, examines the impact that human industrial activity can have on air pollution. In particular, we focus on the remediation of gas-phase and semivolatile organic emissions by emission reduction technologies. This detailed summary of emissions from a current nonroad diesel engine equipped with advanced aftertreatment can be used to more accurately model the impact of anthropogenic emissions on the atmosphere with tools such as the U.S. Environmental Protection Agency’s MOVES2014a model. 相似文献
9.
Gerald L. Ertel 《Journal of the Air & Waste Management Association (1995)》2013,63(9):913-916
Particulate emission sampling was conducted at Dofasco’s No. 2 Coke Want Quench Tower in August 1977. The sampling was performed by York Research Corporation using EPA developed quench tower sampling techniques. Particulate emissions averaged 0.245 lb/ton of coal over 17 tests. The mist eliminator in the tower consists of two rows of zig-zag baffles inclined at 20° from the vertical. Particle size data indicated that the majority of the particulate emissions were less than 10 microns in diameter. A mathematical model was used to predict the effect of particle size and gas velocity on collection efficiency. Pressure drop and re-entrainment are two restrictions which are considered in baffle design. Quench towers are the largest contributor to Dofasco’s allowable off-the-property suspended particulate impingement concentration. 相似文献
10.
Gerald P. Huffman Frank E. Huggins Naresh Shah Robert Huggins William P. Linak C. Andrew Miller 《Journal of the Air & Waste Management Association (1995)》2013,63(7):1106-1114
ABSTRACT Combustion experiments were carried out on four different residual fuel oils in a 732-kW boiler. PM emission samples were separated aerodynamically by a cyclone into fractions that were nominally less than and greater than 2.5 |j.m in diameter. However, examination of several of the samples by computer-controlled scanning electron microscopy (CCSEM) revealed that part of the PM2.5 fraction consists of carbonaceous cenospheres and vesicular particles that range up to 10 |j.m in diameter. X-ray absorption fine structure (XAFS) spectroscopy data were obtained at the S, V, Ni, Fe, Cu, Zn, and As K-edges and at the Pb L-edge. Deconvolution of the X-ray absorption near edge structure (XANES) region of the S spectra established that the dominant molecular forms of S present were sulfate (26-84% of total S) and thiophene (13-39% of total S). Sulfate was greater in the PM2.5 samples than in the PM25+ samples. Inorganic sulfides and elemental sulfur were present in lower percentages. The Ni XANES spectra from all of the samples agreed fairly well with that of NiSO4, while most of the V spectra closely resembled that of vanadyl sulfate (VO?SO4?xH2O). The other metals investigated (i.e., Fe, Cu, Zn, and Pb) also were present predominantly as sulfates. Arsenic was present as an arsen-ate (As+5). X-ray diffraction patterns of the PM2.5 fraction exhibit sharp lines due to sulfate compounds (Zn, V, Ni, Ca, etc.) superimposed on broad peaks due to amorphous carbons. All of the samples contain a significant organic component, with the loss on ignition (LOI) ranging from 64 to 87% for the PM2.5 fraction and from 88 to 97% for the PM2.5+ fraction. Based on 13C nuclear magnetic resonance (NMR) analysis, the carbon is predominantly condensed in graphitic structures. Aliphatic structure was detected in only one of seven samples examined. 相似文献