全文获取类型
收费全文 | 162篇 |
免费 | 1篇 |
专业分类
安全科学 | 13篇 |
废物处理 | 3篇 |
环保管理 | 28篇 |
综合类 | 15篇 |
基础理论 | 15篇 |
污染及防治 | 64篇 |
评价与监测 | 12篇 |
社会与环境 | 11篇 |
灾害及防治 | 2篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 2篇 |
2017年 | 3篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 11篇 |
2012年 | 6篇 |
2011年 | 8篇 |
2010年 | 7篇 |
2009年 | 11篇 |
2008年 | 6篇 |
2007年 | 16篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 10篇 |
2003年 | 6篇 |
2002年 | 9篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 3篇 |
1998年 | 2篇 |
1997年 | 1篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 6篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1984年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1979年 | 1篇 |
1975年 | 1篇 |
排序方式: 共有163条查询结果,搜索用时 15 毫秒
81.
Elin Röös Bojana Bajželj Pete Smith Mikaela Patel David Little Tara Garnett 《Regional Environmental Change》2017,17(2):367-377
Multiple production and demand side measures are needed to improve food system sustainability. This study quantified the theoretical minimum agricultural land requirements to supply Western Europe with food in 2050 from its own land base, together with GHG emissions arising. Assuming that crop yield gaps in agriculture are closed, livestock production efficiencies increased and waste at all stages reduced, a range of food consumption scenarios were modelled each based on different ‘protein futures’. The scenarios were as follows: intensive and efficient livestock production using today’s species mix; intensive efficient poultry–dairy production; intensive efficient aquaculture–dairy; artificial meat and dairy; livestock on ‘ecological leftovers’ (livestock reared only on land unsuited to cropping, agricultural residues and food waste, with consumption capped at that level of availability); and a ‘plant-based eating’ scenario. For each scenario, ‘projected diet’ and ‘healthy diet’ variants were modelled. Finally, we quantified the theoretical maximum carbon sequestration potential from afforestation of spared agricultural land. Results indicate that land use could be cut by 14–86 % and GHG emissions reduced by up to approximately 90 %. The yearly carbon storage potential arising from spared agricultural land ranged from 90 to 700 Mt CO2 in 2050. The artificial meat and plant-based scenarios achieved the greatest land use and GHG reductions and the greatest carbon sequestration potential. The ‘ecological leftover’ scenario required the least cropland as compared with the other meat-containing scenarios, but all available pasture was used, and GHG emissions were higher if meat consumption was not capped at healthy levels. 相似文献
82.
The application of potassium ferrate for sewage treatment 总被引:12,自引:0,他引:12
The comparative performance of potassium ferrate(VI), ferric sulphate and aluminium sulphate for the removal of turbidity, chemical oxygen demand (COD), colour (as Vis400-abs) and bacteria in sewage treatment was evaluated. For coagulation and disinfection of sewage, potassium ferrate(VI) can remove more organic contaminants, COD and bacteria in comparison with the other two coagulants for the same doses used. Also, potassium ferrate(VI) produces less sludge volume and removes more contaminants, which should make subsequent sludge treatment easier. 相似文献
83.
Measurement sensitivity and bias quality control metrics are commonly reported for water-quality parameters measured in the laboratory. Less commonly recognized is that they should also be reported for field-measured parameters. Periodic evaluation helps document data quality and can help serve as early warning if there are problems with methods or techniques that could negatively affect ability to interpret threshold values and trends over time. This study focuses on traditional assessment of bias and introduces a new method for estimating measurement sensitivity of water-quality parameters measured monthly in the field. Alternative measurement sensitivity is a new data quality indicator used to demonstrate how quantifying sensitivity at the measurement level can improve understanding the uncertainty affecting each reported data value. That, in turn, can help interpret the meaning of results from many separate data points measured in the field. In this 30-month study, pH and specific conductance consistently met, and dissolved oxygen did not always meet NPS and USGS quality control standards for bias. Evaluation of dissolved oxygen bias and sensitivity during the study provided impetus to improve calibration techniques that resulted in data that later met quality goals. 相似文献
84.
Manning WJ Paoletti E Sandermann H Ernst D 《Environmental pollution (Barking, Essex : 1987)》2011,159(12):3283-3293
Ethylenediurea (EDU) has been widely used to prevent ozone (O3) injury and crop losses in crop plants and growth reductions in forest trees. Successful use requires establishing a dose/response curve for EDU and the proposed plant in the absence of O3 and in the presence of O3 before initiating multiple applications to prevent O3 injury. EDU can be used to verify foliar O3 symptoms in the field, and to screen plants for sensitivity to O3 under ambient conditions. Despite considerable research, the mode of action of EDU remains elusive. Additional research on the mode of action of EDU in suppressing O3 injury in plants may also be helpful in understanding the mode of action of O3 in causing injury in plants. 相似文献
85.
Pete Bettinger 《Regional Environmental Change》2011,11(3):569-578
Cypress domes are non-transient, disconnected, depressional wetland areas scattered about the southern United States. Baldcypress
(Taxodium distichum (L.) Rich.), swamp tupelo (Nyssa sylvatica var. biflora) and other trees species typically occupy these sites. Even though these areas are relatively fixed on the landscape, given
land use changes over the last 60–70 years, the spatial character of the resource may have undergone some change as well.
A small case study of one Georgia county suggests that there was net decrease in cypress dome land area from 1940 to 2007.
The case study also suggests that there was a significant change in the land class(es) adjacent to or containing cypress domes.
In addition, the physical shape of cypress domes seems to have changed, perhaps due to mechanical treatment of the land during
commercial forestry operations. While the shape of cypress domes that were adjacent to mature forests in 1940 was not significantly
different than the shape of the same cypress domes that were adjacent to mature forests in 2007, the shape of cypress domes
adjacent to agricultural land and pasture/forest land uses in 1940 was significantly different in shape than their 2007 counterparts.
Thus, the value of this study is in suggesting that the physical shape of cypress domes that were once adjacent to agricultural
or pasture/forest lands seems to have changed, perhaps due to mechanical treatment of the land during the transition from
agricultural practices to commercial forestry operations. The study also highlights the need for assessing the hydrologic
changes in wetland function due to changes in cypress dome shape, and due to mechanical operations used along the edges of
cypress domes to effectively adjust their shape. Research along these lines can lead to a better understanding of the spatial
character of the cypress resource in areas that were once used for agricultural or pasture/forest purposes and may lead to
more effective management strategies for protecting its role in society. 相似文献
86.
Mohamed?AbdallaEmail author Mark?Richards Mark?Pogson Jo?U.?Smith Pete?Smith 《Regional Environmental Change》2016,16(8):2357-2368
The Welsh Government is committed to reduce greenhouse gas (GHG) emissions from agricultural systems and combat the effects of future climate change. In this study, the ECOSSE model was applied spatially to estimate GHG and soil organic carbon (SOC) fluxes from three major land uses (grass, arable and forest) in Wales. The aims of the simulations were: (1) to estimate the annual net GHG balance for Wales; (2) to investigate the efficiency of the reduced nitrogen (N) fertilizer goal of the sustainable land management scheme (Glastir), through which the Welsh Government offers financial support to farmers and land managers on GHG flux reduction; and (3) to investigate the effects of future climate change on the emissions of GHG and plant net primary production (NPP). Three climate scenarios were studied: baseline (1961–1990) and low and high emission climate scenarios (2015–2050). Results reveal that grassland and cropland are the major nitrous oxide (N2O) emitters and consequently emit more GHG to the atmosphere than forests. The overall average simulated annual net GHG balance for Wales under baseline climate (1961–1990) is equivalent to 0.2 t CO2e ha?1 y?1 which gives an estimate of total annual net flux for Wales of 0.34 Mt CO2e y?1. Reducing N fertilizer by 20 and 40 % could reduce annual net GHG fluxes by 7 and 25 %, respectively. If the current N fertilizer application rate continues, predicted climate change by the year 2050 would not significantly affect GHG emissions or NPP from soils in Wales. 相似文献
87.
Zade CM Pete UD Patil SS Bhosale JD Hadole CD Kadam MS Bendre RS 《Journal of environmental science and health. Part. B》2012,47(2):136-143
Insect-growth regulators (IGRs) have been receiving foremost attention as potential means of selective insect control. Benzoyl phenyl urea (BPU) is a well-known IGR having chitin synthesis inhibitor activity. Mimics of BPU have been synthesized by suitable derivatization of a naturally occurring monoterpenoid, thymol (2-isopropyl-5-methyl phenol) to form a = series of substituted benzoyl thymyl thioureas (BTTUs) [IVa-f] and benzoyl thymyl ureas (BTUs) [Va-f]. The synthesized compounds have been characterized by (1)H and (13)C NMR, LC-MS and elemental analysis. These derivatives have been screened for their effect on total haemocyte count of Dysdercus koenigii. It has been observed that the introduction of substituted benzoyl thiourea and urea linkage into a thymol ring via an amino group results in higher activity than the parent compound thymol and a comparable pattern of results with the standard insect-growth regulators, Penfluron. Urea [Va-f] compounds exhibited greater effect on Total Haemocyte Count (THC) than thiourea [IVa-f]. Fluoro substitution enhanced the effect on THC more than chloro substituted compounds, while ortho-substitution resulted in a better effect than para-substitution. The results described in this paper are promising and provide new array of synthetic chemicals that may be utilized as insect growth regulators. 相似文献
88.
Natural Resource Dependency and Decentralized Conservation Within Kanchenjunga Conservation Area Project,Nepal 总被引:1,自引:1,他引:0
Kanchenjunga Conservation Area Project (KCAP) in Nepal is among the first protected areas in the world to institute a completely
decentralized system of conservation and development. Proponents of decentralized conservation claim that it increases management
efficiency, enhances the responsiveness to local needs, and promotes greater equity among local residents. This study assessed
local equity by evaluating the levels of dependencies on natural resources among households and the factors affecting that
dependency. Data were collected via detailed surveys among 205 randomly selected households within the KCAP. Natural resource
dependency was evaluated by comparing the ratio of total household income to income derived from access to natural resources.
Economic, social, and access-related variables were employed to determine potential significant predictors of dependency.
Overall, households were heavily dependent on natural resources for their income, especially households at higher elevations
and those with more adult members. The households that received remittances were most able to supplement their income and,
therefore, drastically reduced their reliance on the access to natural resources. Socio-economic variables, such as land holdings,
education, caste, and ethnicity, failed to predict dependency. Household participation in KCAP-sponsored training programs
also failed to affect household dependency; however, fewer than 20% of the households had any form of direct contact with
KCAP personnel within the past year. The success of the KCAP as a decentralized conservation program is contingent on project
capacity-building via social mobilization, training programs, and participatory inclusion in decision making to help alleviate
the dependency on natural resources. 相似文献
89.
Wang X Zheng Q Feng Z Xie J Feng Z Ouyang Z Manning WJ 《Environmental pollution (Barking, Essex : 1987)》2008,156(2):449-453
Most available exposure-response relationships for assessing crop loss due to elevated ozone (O3) have been established using data from chamber and open-top chamber experiments, using a simulated constant O3 concentration exposure (square wave), which is not consistent with the diurnal variation of O3 concentration that occurs in nature. We investigated the response of oilseed rape (Brassica napus L.) to O3 as affected by two exposure regimes: one with a diurnal variation (CF100D) and another with a constant concentration (CF100). Although the two exposure regimes have the same mean O3 concentration and accumulated O3 concentration above 40 ppb (AOT40), our results show that O3 at CF100D reduced biomass and number of pods/plant more than O3 at CF100. Both O3 exposures resulted in larger seed weights/100 pods compared to CF. Numbers of seeds/100 pods were reduced by CF100, while numbers of seeds/100 pods in the CF100D chambers were comparable to those in CF. Our results suggest that chamber experiments that use a constant O3 exposure may underestimate O3 effects on biomass and yields. 相似文献
90.
Engle VD Kurtz JC Smith LM Chancy C Bourgeois P 《Environmental monitoring and assessment》2007,129(1-3):397-412
A classification of U.S. estuaries is presented based on estuarine characteristics that have been identified as important for quantifying stressor-response relationships in coastal systems. Estuaries within a class have similar physical and hydrologic characteristics and would be expected to demonstrate similar biological responses to stressor loads from the adjacent watersheds. Nine classes of estuaries were identified by applying cluster analysis to a database for 138 U.S. estuarine drainage areas. The database included physical measures of estuarine areas, depth and volume, as well as hydrologic parameters (i.e., tide height, tidal prism volume, freshwater inflow rates, salinity, and temperature). The ability of an estuary to dilute or flush pollutants can be estimated using physical and hydrologic properties such as volume, bathymetry, freshwater inflow and tidal exchange rates which influence residence time and affect pollutant loading rates. Thus, physical and hydrologic characteristics can be used to estimate the susceptibility of estuaries to pollutant effects. This classification of estuaries can be used by natural resource managers to describe and inventory coastal systems, understand stressor impacts, predict which systems are most sensitive to stressors, and manage and protect coastal resources. 相似文献