8 research outputs found

    Phytoplankton community structures revealed by pigment signatures in Norwegian and Greenland Seas in summer 2012

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    对2012年中国第5次北极科学考察期间的挪威海和格陵兰海两个断面的光合色素进行了高效液相色谱(HPlC)分级分析,通过藻类色素化学分类分析软件(CHEMTAX)获得了不同浮游植物类群对叶绿素A的贡献,进而得到该海域表层和次表层(30 M)的浮游植物群落结构。结果表明:表层总叶绿素A的浓度为23.59 ng/l,低于次表层的30.38 ng/l,其中浮游植物根据粒径划分对总叶绿素A的贡献由高到低依次是微型浮游植物、小型浮游植物和微微型浮游植物。该海域同时存在葱绿叶绿素(PrASInO)、墨角藻黄素(fuCO)、别藻黄素(AllO)、多甲藻素(PErId)、玉米黄素(zEA)、19-丁墨甲藻黄素(19'bf)和19-六已墨甲藻黄素(19'Hf)等色素,其浓度和分布与温盐和营养盐等环境因子存在一定的相关性。不同粒径浮游植物色素组成显示,微微型浮游植物群落中以S型定鞭藻(28%)、n型定鞭藻(21%)、硅藻(18%)和青绿藻(12%)占优;微型浮游植物群落的优势类群为S型定鞭藻(53%)、n型定鞭藻(20%)和硅藻(12%);而小型浮游植物群落主要为硅藻(63%)和甲藻(17%)。Composition of phytoplankton controlled not only the formation of the Food Chain,but also the efficiency of energy transfer.At the same time,phytoplankton influenced the distribution of nutrient and the sedimentation of organic particulate matter.So study of phytoplankton community structures plays an important role in understanding the ecological function of phytoplankton.Photosynthetic pigments needed by photosynthesis,are very good biomarkers.They can be used to research and characterize phytoplankton community structure.Norwegian and Greenland Seas which are influenced by the Arctic water with low temperature and salinity and Atlantic water with high temperature and salinity.Understanding of correlation between environmental factors and phytoplankton community structure,is important for understanding the community structure of the marine organisms and their ecological function.During the 5thChinese Arctic Research Expedition in summer 2012,we analyze the photosynthetic pigments fromNorwegian and Greenland Seas by HPLC.Contributions of different phytoplankton assemblages to Chlorophyll a were obtained by Chemical Taxonomy( CHEMTAX),and thus resulted in composition of the phytoplankton community structure at the surface and subsurface water( about 30 m depth).The result showed that average concentration of Chlorophyll a at surface water was 23.59 ng / L,lower than that at upper water( 30.38 ng / L).The contributions of phytoplankton to Chlorophyll a were nano-> micro-> pico-one.Prasinoxanthin,Fucoxanthin,Alloxanthoxyletin,Peridinin,Zeaxanthin,19'-but-fucoxanthin,19-hexanoyloxyfucoxanthin were observed in the waters.Their distributions were relative to environmental factors,including Nutrients,temperature and salinity.These photosynthetic pigments showed negative correlations with temperature and salinity.Whereas they showed positive relations with nutrients,including NO-2,NO-3,SiO3 2-and PO3-4.The correlations of different phytoplankton and environmental factors were different.Diatoms had a very significant positive correlation with SiO3 2-,but had no correlation with PO3-4,NO-2and NO-3; Haptophytes-N had significant positive correlations with PO3-4,NO-2and NO-3; Haptophytes-S also had a positive correlation with PO3-4,but had no correlation with NO-2and NO-3.The maximum values of these photosynthetic pigments,except for Zea and Fuco,existed in the subsurface of the section BB.The distribution and concentration of photosynthetic pigments could explain the distribution and abundance of the phytoplankton to some extent.Not only because the pigments are complex and multiple,but also because there are inevitable errors in the testing and sampling,we cant determine the existence and abundance of the phytoplankton.So we use the CHEMTAX to obtain the contributions of different phytoplankton assemblages to Chlorophyll a,and thus resulted in composition of phytoplankton community structure.The composition of phytoplankton showed that Haptophytes-S( 28%), Haptophytes-N( 21%),Diatoms( 18%),and Prasinophytes( 12%) were main assemblages in the picoplankton; the main composition of nanophytoplankton were Haptophytes-S( 53%),Haptophytes-N( 20%),and Diatoms( 12%); meanwhile, Diatoms( 63%) dominated the microphytoplankton,followed by Dinoflagellates( 17%).Haptophytes-S,Haptophytes-N and Diatoms were dominant species in the surface and subsurface of section BB and AT belonging to the Norwegian and Greenland Sea.If Fucoxanthins and Diatomss existence in picophytoplankton could explain the tendency of phytoplankton to micro and miniaturization,these still need to be more sufficient evidence.国家自然科学基金(41076130;41206189); 南北极环境综合考察与评价专项(CHINARE2011-2015

    Driving Safety Alerting Interface Design

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    采用扁平化界面设计思想,实现了基于WInCE5.0/6.0模拟器下驾驶安全预警与导航系统dSA的界面设计。该设计充分考虑驾驶者在行车旅程中的各种需求,将驾驶过程中的安全、可靠、多媒体娱乐功能相接合,在颜色搭配、功能布局上融入扁平化设计思路,使得软件的界面更加美观、友好,操作更加方便,为用户带来更加舒适并且安全的驾驶体验。Using the flat interface design, the DSA interface design based on WinCE5.0/6.0 is implemented.In the process of design we fully considered various demands of drivers, including safety, reliability, and multimedia entertainment functions in the driving.We also considered the design of color, functional layout, making the software interface more beautiful and friendly, operation more convenient, more comfortable and letting drivers experience safe driving.福建省本科高校专业综合改革试点资助项

    准噶尔盆地东南缘天然更新梭梭苗期动态生命表及生存分析

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    运用动态生命表方法,观察和分析了准噶尔盆地东南缘天然梭梭(Haloxylon ammodendron)幼苗生长动态。结果显示:梭梭当年生幼苗存在两个存活率下降快、死亡率和致死力高的阶段。第一阶段从4月1日至5月1日幼苗死亡率为69.9%。第二阶段为6月15日至7月15日,幼苗死亡率由79.1%增加到85.1%。早期生长阶段的高死亡率,是由于动物咬食和不利气候因素的影响;而后一阶段死亡率较高的原因,是由于浅层土壤水分下降所致。存活曲线属DeeveyⅢ型,表明幼苗早期个体死亡率较高,此阶段是幼苗天然更新的关键时期。幼苗期动态生命表的研究可以为梭梭天然更新及其管理措施的制定提供科学依据

    古尔班通古特沙漠边缘春秋季沙丘水分状况初步研究

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    古尔班通古特沙漠边缘植被破坏严重,沙丘活化明显,是新疆干旱区植被恢复的重点地区之一,当地降水稀少,其沙丘的水分状况便成为植被生存和恢复过程的关键条件,为掌握古尔班通古特沙漠边缘流动沙丘和固定沙丘不同部位的水分状况,从2003年3月到10月植物生长期内利用中子仪进行连续监测的结果表明:沙丘含水量月变化与月降水量分布相一致;流动沙丘0-30cm的含水量低于固定沙丘,而其它各层都高于固定沙丘;流动沙丘含水量从上部到下部依次升高,而固定沙丘则并无此规律;流动沙丘中部和下部稳定湿沙层处在距沙丘表面60cm以下,且厚度超过100cm,固定沙丘稳定湿沙层只存在于沙丘中部距沙丘表面60~150cm深度范围内,其厚度不超过100cm

    可见光通信定位集成系统仿真研究

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    为了提升可见光通信(VLC)定位系统的频谱和功率利用率,文章提出了一种基于非对称限幅和直流偏置的光正交频分复用(ADO-OFDM)的VLC定位集成系统。该通信定位集成系统具有比基于非对称限幅的光正交频分复用(ACO-OFDM)的VLC定位集成系统更高的频谱利用率和比基于加直流偏置的光正交频分复用(DCO-OFDM)的VLC定位集成系统更高的功率利用率。同时,文章还提出了一种差分修正定位算法,所提算法较于传统的三边定位算法其具有更高的定位精度

    JUNO Sensitivity on Proton Decay pνˉK+p\to \bar\nu K^+ Searches

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in pνˉK+p\to \bar\nu K^+ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via pνˉK+p\to \bar\nu K^+ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is 9.6×10339.6 \times 10^{33} years, competitive with the current best limits on the proton lifetime in this channel

    JUNO sensitivity on proton decay pνK+p → νK^{+} searches

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    JUNO sensitivity on proton decay p → ν K + searches*

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    The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this study, the potential of searching for proton decay in the pνˉK+ p\to \bar{\nu} K^+ mode with JUNO is investigated. The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via pνˉK+ p\to \bar{\nu} K^+ is 36.9% ± 4.9% with a background level of 0.2±0.05(syst)±0.2\pm 0.05({\rm syst})\pm 0.2(stat) 0.2({\rm stat}) events after 10 years of data collection. The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 9.6 \times 10^{33} years, which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies
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