首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   38篇
  免费   3篇
安全科学   4篇
废物处理   1篇
环保管理   4篇
综合类   2篇
基础理论   9篇
污染及防治   18篇
评价与监测   2篇
社会与环境   1篇
  2020年   4篇
  2018年   1篇
  2017年   2篇
  2016年   2篇
  2015年   1篇
  2014年   3篇
  2013年   6篇
  2010年   1篇
  2009年   1篇
  2008年   4篇
  2007年   1篇
  2006年   1篇
  2005年   1篇
  2003年   1篇
  2002年   1篇
  2001年   2篇
  2000年   2篇
  1996年   1篇
  1994年   1篇
  1993年   1篇
  1988年   1篇
  1984年   1篇
  1981年   1篇
  1968年   1篇
排序方式: 共有41条查询结果,搜索用时 15 毫秒
11.
This study investigated consumer awareness of integrated pest management (IPM) and the effects of two marketing strategies. Specific objectives were to find whether eastern Massachusetts farmstand and farmers' market customers purchasing sweet corn care how their food is grown, whether they are aware of IPM, whether they would prefer to buy IPM-certified sweet corn and why, and whether the marketing methods presently available to IPM-certified growers can enhance awareness of IPM. In 1993, the Massachusetts Department of Food and Agriculture in collaboration with the IPM Program at the University of Massachusetts began a pilot IPM certification program for sweet corn and strawberries, designated ‘Partners with Nature’ (PWN). This study compared a ‘passive’ and ‘active’ PWN marketing strategy with a control that did not have any PWN publicity. The passive strategy was simply display of a PWN certificate and poster. The active strategy also included newspaper advertisements, clear labeling of corn as IPM-certified at the point of selection, a PWN sticker placed on bags of corn at payment, personally thanking customers for ‘buying our IPM-certified sweet corn’, and IPM brochures available to customers. Thirty purchasers of IPM-grown corn were interviewed at each of six farmstands and six farmers' markets.The dominant reason why customers patronize farmstands and farmers' markets was convenience. As found by other northeastern surveys, awareness of IPM was low: only 19% had heard of IPM before the survey, and only 38% of these could mention a specific method used in IPM. Although 45% of the respondents initially said that they did not care how their food is grown, 85% said that they would prefer to buy IPM-certified sweet corn after hearing a short definition. The definition gave only environmental benefits, but 74% of the customers preferring IPM-certified corn said they would buy it because it is safer or healthier. Most of the respondents claimed that they would be willing to pay 10% more for IPM-certified corn. Simply displaying an IPM poster had no significant results on consumer preference for IPM-grown produce, but active marketing significantly raised awareness of IPM and the PWN program.This study demonstrated the willingness of customers to support IPM because they believe it will have positive consequences for human health and environmental quality. It is concluded that sweet corn marketing based on IPM certification positively influenced consumer reactions to IPM; and a more extensive, diverse marketing strategy would enhance consumer awareness and support.  相似文献   
12.
Emission factors for selected volatile organic compounds (VOCs) and particulate material were developed during processing of commercial grades of polyamide 6, polyamide 66, and polyamide 66/6 resins. A small commercial-type extruder was used, and melt temperatures ranged from 475 to 550 degrees F. An emission factor was calculated for each substance measured and is reported as pounds released to the atmosphere per million pounds of polymer resin processed. Scaled to production volumes, these emission factors can be used by processors to estimate emission quantities from similar polyamide extrusion operations.  相似文献   
13.
Blood of adult and juvenile black and turkey vultures in the Savannah River Site of South Carolina, USA was analyzed for the presence of 2,3,7,8-chlorine substituted polychlorinated dibenzo-p-dioxins (2,3,7,8-PCDDs), dibenzofurans (2,3,7,8-PCDFs), -dioxin-like and -di-ortho polychlorinated biphenyls. Concentration ranges of 2,3,7,8-PCDD/DFs in blood of black and turkey vultures were 14.2-34.6 and 8.7-56.2 pg/ml wet wt., respectively. Dioxin-like PCBs were in the ranges of 815-4627 and 753-3611 pg/ml wet wt. respectively, in black and turkey vultures. Considerable concentrations of two congeners of di-ortho PCBs were noticed in the ranges of 1415-10325 and 663-7500 pg/ml respectively, in black and turkey vultures. Comparatively, greater toxic equivalency (TEQ) were observed in blood of turkey vultures with the ranges of 3.2-20, whereas black vulture contained 1.8-8.4 pgTEQ/ml wet wt. basis. The species-specific accumulation profiles of PCDD/DFs and dioxin-like PCBs may reflect the different feeding habits, ecology, metabolic capacity and migratory movements of these two scavenging species.  相似文献   
14.
Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production—the most widespread and long-running commercial use of public lands—can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exacerbate the effects of climate change on these resources. Excess abundance of native ungulates (e.g., deer or elk) and feral horses and burros add to these impacts. Although many of these consequences have been studied for decades, the ongoing and impending effects of ungulates in a changing climate require new management strategies for limiting their threats to the long-term supply of ecosystem services on public lands. Removing or reducing livestock across large areas of public land would alleviate a widely recognized and long-term stressor and make these lands less susceptible to the effects of climate change. Where livestock use continues, or where significant densities of wild or feral ungulates occur, management should carefully document the ecological, social, and economic consequences (both costs and benefits) to better ensure management that minimizes ungulate impacts to plant and animal communities, soils, and water resources. Reestablishing apex predators in large, contiguous areas of public land may help mitigate any adverse ecological effects of wild ungulates.  相似文献   
15.
The aim of this study was to characterize the behaviour of a PAH-degrading bacterium to determine whether mineralization plateaus as a result of substrate removal, a decrease in microbial activity or nutrient availability in sterile soils over time. To investigate this, the mineralization of 14C-phenanthrene was measured until it plateaued; subsequently, additional 14C-phenanthrene, catabolic inocula or nutrients were introduced and mineralization was measured for a further 10 d. Cell numbers were also measured together with 14C-uptake into microbial biomass. Freshly added 14C-phenanthrene was rapidly metabolised by the microorganisms. Neither the addition of a catabolic inoculum nor nutrients affected the extent of 14C-phenanthrene mineralization. Cell numbers remained constant over time, with only a small amount of the 14C-activity incorporated into the microbial biomass. This study indicated that the termination of mineralization was due to the removal of available phenanthrene and not decreasing cellular activity or cell death. The mineralization values also correlated with 14C-phenanthrene extractability using beta-cyclodextrin.  相似文献   
16.
Deletion of the distal end of the short arm of chromosome 1 (1p36) is thought to be a common terminal chromosomal deletion. However, few cases prospectively diagnosed prenatally have been reported. In this case, prenatal ultrasound at 21 weeks of gestation noted the fetus to have mild ventriculomegaly (Vhanterior = 11 mm and Vhposterior = 12 mm) and increased nuchal edema (6 mm). Maternal serum α-fetoprotein was normal unlike in a majority of previously described cases. The prenatal ultrasound features were further clarified with fetal MRI. Chromosome analysis following amniocentesis demonstrated a 1p36 deletion, which was confirmed by fluorescence in situ hybridization (FISH). The syndrome associated with 1p36 deletion is well described in infants and is characterized by typical facial features (prominent forehead, straight eyebrows. deep-set eyes, flat nasal bridge and a pointed chin). Other associated features are neurodevelopmental delay, seizures, cardiomyopathy and neurosensory hearing impairment. This case supplements our knowledge of the prenatal features of 1p36. Identification of this deletion by direct chromosomal analysis can be technically difficult and vigilance is required to improve diagnosis. FISH analysis is an important diagnostic adjunct where the diagnosis is suspected following classical G-banding techniques. However, in this chromosomal anomaly there remain few characteristic prenatal signs that are readily diagnosed with prenatal imaging. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   
17.
The proliferation of linear infrastructure such as roads and railways is a major global driver of cumulative biodiversity loss. One strategy for reducing habitat loss associated with development is to encourage linear infrastructure providers and users to share infrastructure networks. We quantified the reductions in biodiversity impact and capital costs under linear infrastructure sharing of a range of potential mine to port transportation links for 47 mine locations operated by 28 separate companies in the Upper Spencer Gulf Region of South Australia. We mapped transport links based on least‐cost pathways for different levels of linear‐infrastructure sharing and used expert‐elicited impacts of linear infrastructure to estimate the consequences for biodiversity. Capital costs were calculated based on estimates of construction costs, compensation payments, and transaction costs. We evaluated proposed mine‐port links by comparing biodiversity impacts and capital costs across 3 scenarios: an independent scenario, where no infrastructure is shared; a restricted‐access scenario, where the largest mining companies share infrastructure but exclude smaller mining companies from sharing; and a shared scenario where all mining companies share linear infrastructure. Fully shared development of linear infrastructure reduced overall biodiversity impacts by 76% and reduced capital costs by 64% compared with the independent scenario. However, there was considerable variation among companies. Our restricted‐access scenario showed only modest biodiversity benefits relative to the independent scenario, indicating that reductions are likely to be limited if the dominant mining companies restrict access to infrastructure, which often occurs without policies that promote sharing of infrastructure. Our research helps illuminate the circumstances under which infrastructure sharing can minimize the biodiversity impacts of development.  相似文献   
18.
Recent conservation planning studies have presented approaches for integrating spatially referenced social (SRS) data with a view to improving the feasibility of conservation action. We reviewed the growing conservation literature on SRS data, focusing on elicited or stated preferences derived through social survey methods such as choice experiments and public participation geographic information systems. Elicited SRS data includes the spatial distribution of willingness to sell, willingness to pay, willingness to act, and assessments of social and cultural values. We developed a typology for assessing elicited SRS data uncertainty which describes how social survey uncertainty propagates when projected spatially and the importance of accounting for spatial uncertainty such as scale effects and data quality. These uncertainties will propagate when elicited SRS data is integrated with biophysical data for conservation planning and may have important consequences for assessing the feasibility of conservation actions. To explore this issue further, we conducted a systematic review of the elicited SRS data literature. We found that social survey uncertainty was commonly tested for, but that these uncertainties were ignored when projected spatially. Based on these results we developed a framework which will help researchers and practitioners estimate social survey uncertainty and use these quantitative estimates to systematically address uncertainty within an analysis. This is important when using SRS data in conservation applications because decisions need to be made irrespective of data quality and well characterized uncertainty can be incorporated into decision theoretic approaches.  相似文献   
19.
In addition to experimental trials in automotive factories, there is a fundamental need to monitor real people involved in real motor vehicle collisions to determine the impact of automotive design characteristics on injury mortality. To aid in designing future safety features for drivers' seats, data from the Fatal Accident Reporting System (FARS) were used to assess the effects of safety belts, directions of crash impacts, age, sex, and car weights on motor vehicle injury fatalities. Furthermore, because the FARS includes only accidents in which there was at least one fatality, this paper introduces a multivariate approach — a logistic regression conditioned on each accident —to avoid the sampling biases inherent in the FARS. The resulting model is used to quantify the relations among the safety belts, the directions of crash impacts, and vehicle weights and their effects on fatalities. Recause the proposed approach allows researchers to study many important variables simultaneously and eliminates the biases resulting from many possible confounders, the estimates presented in this paper are considered to be more precise and more firmly established than earlier estimates. The new approach to analyzing the FARS data will also be useful for investigating the effects of other risk factors or automotive characteristics on crash fatalities.  相似文献   
20.
ABSTRACT: Grazed pastures represent a potential source of non‐point pollution. In comparison to other nonpoint sources (e.g., row‐cropped lands), relatively little information exists regarding possible magnitudes of nutrient losses from grazed pasture, how those losses are affected by management variables, and how the losses can be minimized. The objective of this study was to measure concentrations of nitrogen (N), phosphorus (P), and solids in runoff from fescue plots and relate those measurements to simulated forage management strategy. The study was conducted at the University of Kentucky Maine Chance Agricultural Experiment Station north of Lexington. Plots (2.4 m wide by 6.1 m long) were constructed and established in Kentucky 31 fescue (Festuca arundinacea Schreb.) to represent pasture. The experimental treatments applied to the plots varied in terms of forage height and material applied (none, manure, or manure and urine). Runoff was sampled for six simulated rainfall events applied over the summer of 1997 and analyzed for nitrate N (NO3‐N), ammonia N (NH3‐N), total Kjeldahl N (TKN), ortho‐P (PO4‐P), total P (TP), and total suspended solids (TSS). All runoff constituents exhibited dependence on the date of simulated rainfall with generally higher concentrations measured when simulated rainfall followed relatively dry periods. The effects of forage height and manure addition were mixed. Highest runoff N concentrations were associated with the greatest forage heights, whereas highest P concentrations occurred for the least forage heights. Manure/urine addition increased runoff P concentrations relative to controls (no manure/urine) for both the greatest and least forage heights, but runoff N concentrations were increased only for the greatest forage heights. These findings indicate that runoff of N and P is at least as sensitive to amount and proximity of preceding rainfall and suggest that managing forage to stimulate growth and plant uptake can reduce runoff of N.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号