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991.
利用高纯锗γ能谱分析仪测量中国华东某铀矿区附近河流沉积物的放射性核素比活度,计算γ辐射吸收剂量率(D)、有效镭浓度(Ra_(eq))、外照射指数(H_(ex))、内照射指数(H_(in))、年有效剂量当量(AEDE(室内和室外))和年性腺剂量当量(AGDE)等放射性参数,并开展沉积物的放射性危害评估,最后通过Pearson线性系数确定放射性核素比活度之间的相关性。结果表明,河流沉积物中放射性核素~(238)U、~(226)Ra、~(232)Th和40K的平均比活度分别为51.55、37.32、57.63和756.86 Bq·kg~(-1),除~(226)Ra外,其他放射性核素的比活度均高于中国平均值;距离污染区较远或存在河流稀释作用的区域,沉积物的天然放射性核素处于正常水平,作为建筑材料使用时比活度不存在超标;放射性核素~(238)U、~(226)Ra和~(232)Th之间存在显著相关性。 相似文献
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Gavin McDonald Molly Wilson Diogo Veríssimo Rebecca Twohey Michaela Clemence Dean Apistar Stephen Box Paul Butler Fel Cesar Cadiz Stuart J. Campbell Courtney Cox Micah Effron Steve Gaines Raymond Jakub Roquelito H. Mancao Pablo T. Rojas Rocky Sanchez Tirona Gabriel Vianna 《Conservation biology》2020,34(5):1176-1189
Small-scale fisheries are an important livelihood and primary protein source for coastal communities in many of the poorest regions in the world, yet many are overfished and thus require effective and scalable management solutions. Positive ecological and socioeconomic responses to management typically lag behind immediate costs borne by fishers from fishing pressure reductions necessary for fisheries recovery. These short-term costs challenge the long-term success of these interventions. However, social marketing may increase perceptions of management benefits before ecological and socioeconomic benefits are fully realized, driving new social norms and ultimately long-term sustainable behavior change. By conducting underwater visual surveys to quantify ecological conditions and by conducting household surveys with community members to quantify their perceptions of management support and socioeconomic conditions, we assessed the impact of a standardized small-scale fisheries management intervention that was implemented across 41 sites in Brazil, Indonesia, and the Philippines. The intervention combines TURF reserves (community-based territorial use rights for fishing coupled with no-take marine reserves) with locally tailored social-marketing behavior change campaigns. Leveraging data across 22 indicators and 4 survey types, along with data from 3 control sites, we found that ecological and socioeconomic impacts varied and that communities supported the intervention and were already changing their fishing practices. These results suggest that communities were developing new social norms and fishing more sustainably before long-term ecological and socioeconomic benefits of fisheries management materialized. 相似文献
995.
中国政府环境信息公开实施效果评价 总被引:4,自引:0,他引:4
环境信息公开是国际上公认的新一代环境治理手段,也是我国建设"阳光政府"的基本要求.在《环境信息公开办法》实施2 a后,针对31个省级、5个计划单列市和27个省会城市环境保护局落实环境信息公开的制度和行动进行调查分析,通过资料调查、实际公开申请和深入访谈,全面评估政府环境信息公开办法实施的有效性,以期为该办法的进一步完善... 相似文献
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Dorcas Ibukun Akinloye Taofik Olatunde Sunmonu Samuel Olatunbosun Omotainse Elisabeth Abidemi Balogun 《毒物与环境化学》2015,97(2):155-169
This study investigated antioxidant status of animals given aqueous extract of Morinda morindoides leaves using the levels of reduced glutathione, total-thiol, vitamin C, and vitamin E as well as malondialdehyde concentrations as indices, and its in vitro antioxidant capacity. Thirty rats divided into five groups were used. Group A served as control and were administered distilled water while groups B, C, D, and E were given 100, 200, 400, and 800 mg per kilogram body weight of water-extracted constituents of M. morindoides for 28 days. Total phenolic compounds amounted to 83.6 ± 5.9 mg g?1 gallic acid equivalent, while total flavonoid content was 9.5 ± 0.9 mg g?1 pyrocathecol equivalent. Malondialdehyde in plasma was significantly decreased in a dose-dependent manner, ranging from 21% in groups B and C to 84% in groups D and E. Vitamins C and E were significantly increased, in group E by 91% and 17% compared with control. Total thiols and glutathione in plasma were significantly increased, with group E having 2.5-fold and 4.2-fold higher values than control. 相似文献
998.
温室效应气体及其监测方法 总被引:1,自引:0,他引:1
本文就CO_2、N_2O、CH_4及氟里昂等几种主要温室效应气体之最新监测动向进行综述,引述文献28篇. 相似文献
999.
The effect of drainage and outburst elimination are obviously different between soft and hard coal sub-layers under per-drainage of coal seam, and hence, the location of per-drainage borehole related to the soft sub-layer is the key that determines whether the outburst can be eliminated in whole coal seam. This paper discusses the differences between soft and hard coal from fields of pore radius distribution, pore structure, surface area and permeability, and the per-drainage effect was numerical simulated under different distance between per-drainage hole and soft sub-layer. Moreover, the optimum hole arrangement of outburst elimination is given in the paper. The result of research shows that the macro-pore with aperture that is larger than 50,000 nm, is dominant at about 50% in hard coal, correspondingly, the micro-pore with aperture less than 100 nm accounts for about 41.23% in soft coal. The surface area of soft coal is 1.6 times as that of hard coal. The residual gas content in soft coal sub-layer is obviously more than it in hard coal sub-layer under the same pre-drainage condition. To 5.5 m-thick coal seams which top is a soft coal sub-layer of 0.5 m-thick, pre-drainage gas can eliminate danger of gas outburst in whole coal seam at the seam time after 455 days drainage when the per-drainage holes are 1.0 m distances from the soft coal sub-layer. 相似文献
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