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61.
对大亚湾3种重要经济鱼类包括黑鲷Sparusmacrocephalus、平鲷Rhabdosargussarba和细鳞Theraponjarbua的多项温度指标进行室内热效应模拟研究。结果表明:在驯化温度为25—33℃条件下,黑鲷、平鲷和细鳞3种鱼类的起始致死温度分别为34.96─36.42,34.78─35.62,38.75─39.39℃;最高起始致死温度分别为36.35,35.52℃和39.32℃;临界热最大值分别为38.08─40.50,38.28─40.40℃和42.40─43.64℃;最适生长温度分别为28,28℃和32℃;生长的最高周平均温度分别为30.78,30.51℃和34.44℃;短期暴露最高温度分别为34.04,33.57℃和37.90℃。根据黑鲷、平鲷和细鳞的多项温度指标,结合这些鱼类的生活习性分析和大亚湾基本环境特征的调查资料,就大亚湾核电站温排水对渔业资源影响的热效应问题进行初步探讨。 相似文献
62.
土地储备出让工作是我国为改变传统的土地供应模式、规范调控土地市场、优化土地资源配置,实现土地收益的最大化而做出的重大创新。通过调查研究并结合蓬莱市土地储备出让工作运行实际,就土地储备出让过程中存在的问题作出分析并提出相应建议。 相似文献
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SD法在湖北大冶鸡冠嘴铜金矿床资源储量核实中的应用 总被引:4,自引:0,他引:4
SD法是一种全新的储量计算和审定方法,是我国使用的三大储量计算方法(传统法、克里格法和SD法)之一.根据国土资源部的指示和要求,湖北三鑫金铜股份有限公司和北京恩地科技发展有限责任公司共同对矿区的13条勘探线、20个矿体、16个中段的资源储量运用SD法进行了全面的复核计算,成功地确定了鸡冠嘴铜金矿矿床-160~-170 m、-170~-470 m、-470 m以下铜和金的保有储量. 相似文献
66.
《African Journal of Marine Science》2013,35(2):233-240
Once one of the most numerous seabirds of the Benguela upwelling system, the population of Cape cormorants Phalacrocorax capensis has decreased by 60% in the past three decades and the species is listed as Near Threatened. Declines in prey availability and/or abundance brought about by recent changes in the distribution of pelagic fish stocks and industrial purse-seine fishing are hypothesised to be a key driver of seabird population decreases in the southern Benguela. We investigated the foraging behaviour of breeding Cape cormorants by deploying GPS and temperature–depth recorders on 24 breeding adults from three islands off the coast of South Africa, two of them to the north of Cape Point and a third farther south on the western Agulhas Bank. This provided the first measures of foraging dispersal by a cormorant in the Benguela system, and enabled a comparison of foraging behaviour between birds from these islands. Foraging trips of Cape cormorants lasted between 17 min and >7 h, at a maximum distance of between 2 and 58 km away from their colony. Foraging effort was significantly greater for birds from farther north off the West Coast in terms of trip duration, distance travelled, number of dives and time spent flying compared to those from the southernmost island (Dyer), which is probably a response to low prey availability in the north. Coastal reserves that exclude pelagic fishing from inshore feeding grounds around Cape cormorant breeding colonies may result in increased local prey availability, which would benefit Cape cormorant populations. 相似文献
67.
Cynthia F. Lewis Stopher L. Slade Kerry E. Maxwell Thomas R Matthews 《新西兰海洋与淡水研究杂志》2013,47(1):271-282
Commercial fishers report finding their lobster traps often great distances from their original location following major hurricanes. But traps also move during lesser wind events, such as during winter cold fronts. To assess trap impact on coral communities following winter storms, lobster traps were placed in hardbottom and reef habitats commonly used by commercial fishers in the Florida Keys, United States. Trap movement, percentage benthic faunal cover, and benthic faunal damage were assessed after 26 wind events occuring over three winters. Traps moved when storms with sustained winds greater than 15 knots (27.8 km/h) persisted for more than 2 days. Winter storms above this threshold moved buoyed traps a mean (±SE) distance of 3.63 ± 0.62 m, 3.21 ± 0.36 m, and 0.73 ± 0.15 m per trap and affected a mean area of 4.66 ± 0.76 m2, 2.88 ± 0.29 m2, and 1.06 ± 0.17 m2, per trap at 4‐m, 8‐m, and 12‐m depths, respectively. Unbuoyed traps, simulating derelict traps, moved a mean distance of 0.43 ± 0.08 m and 0.44 ± 0.02 m, and affected a mean area of 0.77 ± 0.06 m2 and 0.90 ± 0.08 m2 per trap at 4‐m and 8‐m depths, respectively. Injuries caused by trap movement included scraped, fragmented, and dislodged sessile fauna, resulting in significant damage to stony coral, octocoral, and sponges. Overall, sessile fauna cover along the trap movement path was reduced from 45% to 31%, 51% to 41%, and 41% to 35% at the 4‐m, 8‐m, and 12‐m sites, respectively. Because of the large numbers of traps deployed and reported lost each season, damage to sessile fauna and loss of benthic faunal cover caused by traps needs to be considered to effectively protect coral reefs and manage essential fishery habitat in the future. 相似文献
68.
通过南方地区页岩气藏的储层特征和赋存方式的研究,认为页岩各组分含量的准确计算直接关系到含气量评价的精度.以南方3个工区计74块岩心样品组分分析实验为基础,提出页岩的五元工业组分体积模型和体积含量计算方法.对其中表征页岩含气性最关键组分——干酪根(有机碳)含量,分别建立与三孔隙度、电阻率、铀元素等5条测井曲线的线性关系.通过有机碳敏感性分析,引入两种多元回归计算有机碳含量方法,确定了适用于3个南方地区有机碳含量的公式.3口探井应用实例表明该方法符合页岩气藏的实际,提高了页岩气层各组分含量的计算精度,取得了预期的地质效果. 相似文献
69.
?????????????λ??????????????????????????????????t??????????????????????????????????????????????????λ?????GPS????????????????????????????mm/s?????????????1 cm/s?? 相似文献
70.