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1.
ROZINA Tinkara ELER?EK Tina Maja ZUPAN?I? JUSTIN MEGLI? Andrej LE?TAN Domen SEDMAK Bojan 《中国海洋湖沼学报》2018,(4)
The increasing occurrence of cyanobacterial blooms in water bodies is a serious threat to the environment. Efficient in-lake treatment methods for the control of cyanobacteria proliferation are needed, their in-vivo detection to obtain a real-time response to their presence, as well as the information about their physiological state after the applied treatment. In-vivo fluorescence measurements of photosynthetic pigments have proved to be effective for quantitative and qualitative detection of phytoplankton in a water environment. In the experiment, chlorophyll and phycocyanin fluorescence sensors were used concurrently to detect stress caused by electrochemical oxidation applying an electrolytic cell equipped with borondoped diamond electrodes on a laboratory culture of cyanobacteria Microcystis aeruginosa PCC 7806. The inflicted injuries were reflected in a clear transient increase in the phycocyanin fluorescence signal(for 104 %? 43%) 24 h after the treatment, which was not the case for the chlorophyll fluorescence signal. In the next 72 h of observation, the fluorescence signals decreased(on 40% of the starting signal) indicating a reduction of cell number, which was confirmed by cell count(24% reduction of the starting concentration) and analysis of extracted chlorophyll and phycocyanin pigment. These results demonstrate the viability of the combined application of two sensors as a useful tool for in-vivo detection of induced stress, providing real-time information needed for the evaluation of the efficiency of the in-lake treatment and decision upon the necessity of its repetition. The electrochemical treatment also resulted in a lower free microcystins concentration compared to control. 相似文献
2.
In this study, two designs for a buoy capable of supporting a 10 kW wind turbine and its tower were developed to operate at the University of New Hampshire’s Center of Ocean Renewable Energy testing site located off the Isles of Shoals, New Hampshire. The buoys are to be moored by a catenary chain system. To evaluate wave response, two Froude-scaled models were constructed, tested, and compared at the Ocean Engineering wave tank at the University of New Hampshire. These buoys have been implemented and compared with wave tank measurements of the spar displacement at a reference elevation 2.44 m above the mean water level. 相似文献
3.
Concentrations of some heavy metals and trace elements such as Cr, Ga, Ni, Zn, Mo, Cu, Pb, Yb, Y, Nb, Ti, Sr, Ba, Mn, Sc, Co, V, Zr, Fe, Al, W, Se, Bi, Sb, As, Cd in recent mollusk shells and factors affecting their distribution and deposits collected from various depths in the southern and southwestern parts of the Marmara Sea are investigated. The distribution of the elements in the shells is categorized into four groups. Of these, concentrations of 12 elements (As, Bi, Cd, Co, Ga, Mo, Nb, Sb, Se, Sc, W and Yb) are below zero [(0.053-0.79)×10^-6]; concentrations of seven elements (Cr, Ni, Pb, V, Y, Zr and Cu) are (1.0-6.0)×10^-6; concentrations of four elements (Ti, Mn, Ba and Zn) are 10- 20×10^-6; and concentrations of five elements (Si, Al, Fe, Mg and Sr) are (47.44-268.11)×10^-6. The taxonomic characteristics of the 29 elements were studied separately in mollusk shells such as Chamalea gallina (Linn6), Pitar rudis (Poli), Nassarius reticulatus (Linn6), Venerupis senescens (Coocconi), Mytilus galloprovincialis (Lamarck), Mytilaster lineatus (Gemelin in Linne) and Chlamys glabra. It was found that, in mollusk taxonomy, the elements have unique values. In other words, element concentrations in various mollusk shells depend mainly on the taxonomic characteristics of mollusks. In various bionomic environments different element distributions of the same species are attributed to the different geochemical characters of the each environment. Data obtained in this study indicate that the organisms are the most active and deterministic factors of the environment. 相似文献
4.
铁路是国家的重要基础设施,是国民经济的重要基础产业部门,是国民经济的大动脉,在国家综合交通体系中起着重要的骨干作用。而铁路用地,是铁路运输生产的重要基础,是维护铁路运输安全的重要条件,是铁路经营的重要资产,是铁路改革发展的重要资本。铁路用地资产量庞大等特点,决定了铁路用地管理工作是铁路改革发展的重要组成部分,因此,加强铁路用地管理,推行铁路局内部土地使用证,是有效发挥土地管理为铁路改革和发展提供保障和服务的有益探索。 相似文献
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7.
祁连山北缘老君庙背斜晚新生代磁性地层与高原北部隆升 总被引:36,自引:2,他引:36
河西走廊新生代沉积敏感地记录了青藏高原北部的构造隆升过程. 酒泉盆地玉门老君庙剖面高分辨率磁性地层研究表明, 疏勒河组胳塘沟段和牛胳套段的年龄分别为>13~8.3 Ma和8.3~<4.9 Ma, 玉门砾岩、酒泉砾石层和戈壁砾石层的年龄分别为3.66~0.93, 0.84~0.14和0.14~0 Ma. 岩性和岩相变化表明祁连山自约8 Ma起, 6.6 Ma略有加速, 由较低的高度开始逐步隆起, 盆地沉积从细粒的湖相砂岩-泥岩逐步转变成粗粒的洪积扇沉积, 至约3.66 Ma后, 祁连山开始急剧地整体快速隆升, 并经约<2.94~2.58, <1.8~1.23, 0.93~0.84和0.14 Ma多次阶段性快速隆升, 祁连山最终被抬升到今天的高度. 相似文献
8.
地名档案是人们从事地名工作最原始最直接的真实记录,同时也是地名工作者赖以生存和提高工作效率不可或缺的必要条件。当前的地名档案,内容丰富、涉及面广,而且表现形态多种多样:文、表、图、卡、袋、册、盒、卷,文字的、声像的、图表的样样俱全,这是地名档案区别于其它文书档 相似文献
9.
The thermal strati?cation of the lakes impedes the transfer of atmospheric oxygen into the lower layers of the lake. In lakes which are af fected by diverse anthropogenic in?uences, the increasing organic matter amounts lead to a sharp decrease in hypolimnetic oxygen amounts, aided by thermal strati?cation,and anaerobic conditions arise. The determination of hypolimnetic oxygen demand(HOD) and areal hypolimnetic oxygen demand(AHOD) and their monitoring represent an integrated approach to investigate the oxygenation of lakes, the nutrient conditions, and the physicochemical dynamics. In this study, two lakes dif fering by size and af fected by dif ferent anthropogenic sources, are investigated in this respect. At?rst, bathymetric studies were conducted to determine the depth, surface area, and volume relationships.Then, based on monitoring studies conducted in 2013 and 2014, the thermal strati?cation dynamics and layer properties were established using the relative thermal resistance to mixing(RTRM) index based on temperature and density pro?les. Following this, the oxygen depletion rates were determined by oxygen and temperature pro?ling in the hypolimnion. For the years of 2013 and 2014, the AHOD values for the Borabey Pond which is far from anthropogenic in?uences, were found to be 0.848 and 0.569 g O 2/(m·d), respectively.The AHOD values for the Porsuk Reservoir which was overburdened for years by industrial and domestic pollution were found to be 4.263 and 5.099 g O 2/(m·d), larger than its counterpart by almost sevenfold. The HOD and AHOD monitoring can be considered to a valuable tool for assessing the ecological and chemical status of lakes within Annex 5 of the Water Framework Directive and as an integrated approach to assess and monitor the status of lakes. 相似文献
10.
通过内蒙古地区近46 a降水和潜在蒸散量以及湿润度在气温突变前后的倾向率和差值变化分析,得出该区域主要植被类型干湿环境演变的时空变化特征。研究结果表明:降水在气温突变前“东增西减”,突变后呈相反的变化趋势。46 a降水倾向率增加区域主要集中在呼伦贝尔市东部和乌兰察布市以西大部地区;潜在蒸散量在气温突变前呈减少趋势,突变后有增加趋势,突变后潜在蒸散量明显小于突变前。内蒙古46 a潜在蒸散量倾向率大部地区偏小,偏大区域仅存在于中东部偏北地区,气温突变后全区大部地区存在明显的“蒸发悖论”;大兴安岭西麓和乌兰察布市以西地区突变后湿润度增加明显,暖湿的气候环境有利于当地植被建设和生态恢复,内蒙古东南部、呼伦贝尔草原和锡林郭勒盟草原区有暖干化趋势,上述草原区存在潜在退化风险。 相似文献