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31.
Abstract:  We identified 100 scientific questions that, if answered, would have the greatest impact on conservation practice and policy. Representatives from 21 international organizations, regional sections and working groups of the Society for Conservation Biology, and 12 academics, from all continents except Antarctica, compiled 2291 questions of relevance to conservation of biological diversity worldwide. The questions were gathered from 761 individuals through workshops, email requests, and discussions. Voting by email to short-list questions, followed by a 2-day workshop, was used to derive the final list of 100 questions. Most of the final questions were derived through a process of modification and combination as the workshop progressed. The questions are divided into 12 sections: ecosystem functions and services, climate change, technological change, protected areas, ecosystem management and restoration, terrestrial ecosystems, marine ecosystems, freshwater ecosystems, species management, organizational systems and processes, societal context and change, and impacts of conservation interventions. We anticipate that these questions will help identify new directions for researchers and assist funders in directing funds.  相似文献   
32.
The Passive Aldehydes and Ketones Sampler (PAKS) method has been developed to measure airborne carbonyls (aldehydes and ketones) by derivatizing the carbonyls with dansylhydrazine (DNSH) on a solid sorbent. The method collection efficiencies are approximately 100% for most saturated carbonyls, but are significantly lower for unsaturated carbonyls. In this study, we examined the mechanisms of DNSH reactions with unsaturated carbonyls, focusing on acrolein. With a better understanding of these mechanisms, we modified the sampling substrate conditions and HPLC analysis conditions of the original PAKS method, resulting in substantially improved collection efficiencies for acrolein and crotonaldehyde. Evaluated under a variety of conditions (temperature, humidity, presence of ozone), the modified PAKS method had a collection efficiency of 99%+/- 5% for acrolein (N= 36) and 96%+/- 20% for crotonaldehyde (N= 6). The acrolein-DNSH derivative was stable within 9.6% of the initial amount, after 14 days of storage at 4 degrees C, on the collection medium; and stable within 2.8% of the initial amount, after 16 days of storage at room temperature, in extract.  相似文献   
33.
城市道路绿化带不同植物叶片附尘对大气污染的磁学响应   总被引:2,自引:1,他引:2  
隆茜  周菊珍  孟颉  达良俊 《环境科学》2012,33(12):4188-4193
对上海市金沙江路两侧绿化带内24个常绿植物叶片样品进行了磁性与重金属测试,以探讨城市道路绿化带不同植物叶片附尘对大气污染的磁学响应.结果表明,χ、SIRM值分别在(4~59)×10-8m3.kg-1和(496~6 114)×10-6Am2.kg-1之间变化,S-300 mT在89%~98%之间变动.所有植物样品中χARM/χ〈4,χARM/SIRM〈30×10-5mA-1.磁性参数表明,植物叶片附尘以亚铁磁性矿物为主,磁性矿物颗粒以假单畴(PSD)-多畴(MD)为主.重金属元素Zn、Cu、Pb含量与反映亚铁磁性矿物含量的χ、SIRM、χARM呈显著正相关,可以将磁性参数SIRM作为叶片重金属元素的替代指标.推荐在上海地区广泛种植的广玉兰作为道路植物污染的指示植物。  相似文献   
34.
PROBLEM: Accidents involving temporary access systems, particularly temporary scaffolds, account for a large proportion of injuries in the construction industry worldwide. METHOD: This paper outlines the development of a prototype decision aid (SCAFPASS, an abbreviation for Scaffold Planning Aid for System Safety) to promote access scaffold safety. It was guided by an examination of the root-causes and management deficiencies apparent in: (a) paper-based files of 186 access-related incidents held by the Health and Safety Executive (HSE) in the UK; and (b) computer-based files of 2,910 incidents appearing in the HSE database between 1997 to 2000. RESULTS: The more frequent root-causes included the fitting of defective components, unauthorized modification of the structure, omission of barriers, and errors resulting in simple, readily detectable structural faults. Common managerial deficiencies included failure to control risk, unsafe methods and procedures, and inadequate training and supervision. IMPACT ON INDUSTRY: SCAFPASS aims to avoid these root-causes by improving safety management from the outset and throughout all phases of a project.  相似文献   
35.
Hunsaker, Carolyn T., Thomas W. Whitaker, and Roger C. Bales, 2012. Snowmelt Runoff and Water Yield Along Elevation and Temperature Gradients in California’s Southern Sierra Nevada. Journal of the American Water Resources Association (JAWRA) 48(4): 667‐678. DOI: 10.1111/j.1752‐1688.2012.00641.x Abstract: Differences in hydrologic response across the rain‐snow transition in the southern Sierra Nevada were studied in eight headwater catchments – the Kings River Experimental Watersheds – using continuous precipitation, snowpack, and streamflow measurements. The annual runoff ratio (discharge divided by precipitation) increased about 0.1 per 300 m of mean catchment elevation over the range 1,800‐2,400 m. Higher‐elevation catchments have lower vegetation density, shallow soils with rapid permeability, and a shorter growing season when compared with those at lower elevations. Average annual temperatures ranged from 6.8°C at 2,400 m to 8.6 at 1,950 m elevation, with annual precipitation being 75‐95% snow at the highest elevations vs. 20‐50% at the lowest. Peak discharge lagged peak snow accumulation on the order of 60 days at the higher elevations and 20 to 30 days at the lower elevations. Snowmelt dominated the daily streamflow cycle over a period of about 30 days in higher elevation catchments, followed by a 15‐day transition to evapotranspiration dominating the daily streamflow cycle. Discharge from lower elevation catchments was rainfall dominated in spring, with the transition to evapotranspiration dominance being less distinct. Climate warming that results in a longer growing season and a shift from snow to rain would result in earlier runoff and a lower runoff ratio.  相似文献   
36.
中老年游客是免费公园游客人群的主要群体,以上海市27座免费公园为例,分析中老年两年龄段游客行为特征,以及其对公园设施服务的重要性和满意度。结果表明:中年游客具有择园路程范围广,公共交通利用率高,来园频率低,入园时间晚,喜爱亲子活动,停留时间短等特征;而老年游客则表现出偏爱短距离公园,以步行为主,来园频率高,入园时间早,倾向运动健身,停留时间长等特征。两年龄段游客对公园满意度评价总体相近,均认为绿化、卫生状况和安全性,以及景点、厕所和无障碍设施设置是影响游客来园的关键因子,前3项令游客满意,而后3项却达不到期望。针对两年龄段游客不同的行为和满意度特征,对免费公园的经营管理提出建议。  相似文献   
37.
对甲烷排放的精准监测是油气行业实现温室气体减排与管控的基础和前提。无人机具有灵活、可操作性强、覆盖范围广、运行成本低等特点,以无人机为飞行平台的甲烷监测技术在油气行业区域甲烷排放监测领域具有巨大的应用潜力。详细阐述了基于无人机平台的甲烷监测技术的优势,梳理了不同的无人机类型,并根据其飞行性能及载荷能力进行了比对,归纳了无人机有效载荷类型、特点及应用场景,总结了国内外无人机甲烷监测技术在油气行业的应用,旨在为基于无人机平台的甲烷监测技术在我国油气行业的应用提供理论和技术参考。  相似文献   
38.
ABSTRACT: A stochastic estimation of low flow in the upper reaches of streams is needed for the planning, development, and management of water resources and/or water use systems. In this paper, the definition and development procedure for the stochastic flow duration curve is presented and applied to five catchments located in eastern Japan and to two catchments in western Thailand. The probability distribution of N‐year daily discharge data is extracted at various percentages of time for which specified discharges are equaled or exceeded in a water year. Such a distribution is usually represented with a straight line on log‐normal probability paper. However, some of the probability plots for the annual minimum daily discharge are best represented with a straight line on Weibull probability paper. The effectiveness of the stochastic flow duration curve defined for the evaluation of flow regime is illustrated through its application. The ten year probability for the discharge exceeded 97 percent of the time may be recognized as an index of low flow. The recession shape of the lower part of the flow duration curve is dependent on the strength of low flow persistence.  相似文献   
39.
From June 2013 to March 2015, in total 41 passive sampler deployments of 2 wk duration each were conducted at 17 sites in South Philadelphia, PA, with results for benzene discussed here. Complementary time-resolved measurements with lower cost prototype fenceline sensors and an open-path ultraviolet differential optical absorption spectrometer were also conducted. Minimum passive sampler benzene concentrations for each sampling period ranged from 0.08 ppbv to 0.65 ppbv, with a mean of 0.25 ppbv, and were negatively correlated with ambient temperature (–0.01 ppbv/°C, R2 = 0.68). Co-deployed duplicate passive sampler pairs (N = 609) demonstrated good precision with an average and maximum percent difference of 1.5% and 34%, respectively. A group of passive samplers located within 50 m of a refinery fenceline had a study mean benzene concentration of 1.22 ppbv, whereas a group of samplers located in communities >1 km distant from facilities had a mean of 0.29 ppbv. The difference in the means of these groups was statistically significant at the 95% confidence level (p < 0.001). A decreasing gradient in benzene concentrations moving away from the facilities was observed, as was a significant period-to-period variation. The highest recorded 2-wk average benzene concentration for the fenceline group was 3.11 ppbv. During this period, time-resolved data from the prototype sensors and the open-path spectrometer detected a benzene signal from the west on one day in particular, with the highest 5-min path-averaged benzene concentration measured at 24 ppbv.

Implications: Using a variation of EPA’s passive sampler refinery fenceline monitoring method, coupled with time-resolved measurements, a multiyear study in South Philadelphia informed benzene concentrations near facilities and in communities. The combination of measurement strategies can assist facilities in identification and mitigation of emissions from fugitive sources and improve information on air quality complex air sheds.  相似文献   

40.
利用层次分析和专家打分法构建了气候变化对内蒙古马铃薯生产的脆弱性影响评价指标体系,运用脆弱性的定义及灾害风险的理论建立了马铃薯脆弱性综合指数评估模型,通过分析主产区的敏感性、适应性来评估脆弱性影响程度.结果表明:内蒙古马铃薯生产脆弱性分布呈中部高、东西部低的分布特点.以乌兰察布市中部、呼和浩特市南部、包头市南部及锡林郭...  相似文献   
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