苏北浅滩沉积物中的大型绿藻微观繁殖体的垂直分布和物种多样性   总被引：1，自引：0，他引：1  

刘峰  刘兴凤  金柘  于仁成  孔凡洲  颜天 《海洋与湖沼》2018,49(5):983-990

本研究通过在2017年秋冬季组织实施的2个绿潮种源调查航次,研究苏北浅滩紫菜养殖区沉积物中的大型绿藻微观繁殖体的垂直分布和物种多样性。对沉积物中的微观繁殖体的定量实验结果表明:表层泥样中绿藻微观繁殖体的丰度最高,随着深度的增加迅速降低。在9月份表层沉积物中丰度为9±2ind./g,而在11月份表层丰度达到98±25ind./g;与9月份相比, 11月份浅滩沉积物中绿藻繁殖体数量呈现出显著升高的趋势。通过对51个绿藻样品的分子鉴定发现:沉积物中存在石莼属(Ulva)、尾孢藻属(Urospora)、盘苔属(Blidingia)等大型绿藻的微观繁殖体;数量占优是石莼属繁殖体,主要包括曲浒苔(Ulva flexuosa)、浒苔(Ulva prolifera)、扁浒苔(Ulva compressa)、缘管浒苔(Ulva linza);其中曲浒苔占据的比例最高,在9和11月份分别达到80.94%和73.33%。在2个调查航次中,都从沉积物中发现了绿潮浒苔的微观繁殖体,这些微观繁殖体是绿潮浒苔在苏北浅滩种源维持的重要方式和关键阶段,也构成了黄海浒苔绿潮连年暴发的"种子库"。  相似文献   

Preliminary investigation of mercury in bone tissues of skua and penguin in Antarctica using AFS and Synchrotron Radiation X-ray Fluorescence （SR-XRF）   总被引：1，自引：0，他引：1  

谢周清程邦波  孙立广黄宇营 何伟 《极地研究(英文版)》2005,16(1):33-40

Mercury （Hg） was investigated in bone tissues of skua （ Catharacta maccormick） and penguin （Pygoscelis adeliae） collected in the maritime Antarctic using atomic fluorescence spectrometry （AFS） and synchrotron radiation X-ray fluorescence （SR-XRF） method. The total levels of mercury in bone tissues of penguin and skua are much lower than those in other organs （e. g. , kidney, liver）. The toxic effects of mercury in bone tissues of seabirds in polar region are not known. We have used SR- XRF method to map the distribution of trace levels of mercury in bones. The levels of mercury are found to be enriched somewhere near the periosteal surface and/or endosteal surface. The distribution of mercury shows strongly correlation with that of some essential elements and probably poses negative effect on the bone metabolism inferring from the relationship of mercury with the other elements. These studies represent a first step toward understanding the toxic effects of mercury on bone of polar animals by suggesting the possible microscopic investigation.  相似文献   

Revised masses of dust and gas of SCUBA Local Universe Survey far-infrared bright galaxies based on a recent CO survey     

Ernest Seaquist  Lihong Yao  Loretta Dunne  Heather Cameron 《Monthly notices of the Royal Astronomical Society》2004,349(4):1428-1434

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Near-Infrared Imaging Spectrophotometry Of Comet C/1995 O1 (Hale-Bopp) Near Perihelion     

Harker  David E.  Woodward  Charles E.  McMURTRY  Craig W.  Goetz  J. A.  Pipher  J. L.  Forrest  W. J. 《Earth, Moon, and Planets》1997,78(1-3):259-264

We present 1- to 5-μm broadband and CVF images of comet Hale-Bopp taken 1997 February 10.5 UT, 50 days before perihelion. All the images exhibit a nonspherical coma with a bright “ridge” in the direction of the dust tail approximately 10″ from the coma. Synthetic aperture spectrophotometry implies that the optically important grains are of a radius ≤0.4 μm; smallest radius for any comet seen to date. The variation of the integrated surface brightness with radial distance from the coma (ρ) in all the images closely follows the “steady state” ρ⁻¹ model for comet dust ablation (Gehrz and Ney, 1992). The near-infrared colors taken along the dust tail are not constant implying the dust grain properties vary with coma distance. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Testing the circumstellar disc hypothesis: a search for H₂ outflow signatures from massive young stellar objects with linearly distributed methanol masers     

J. M. De Buizer 《Monthly notices of the Royal Astronomical Society》2003,341(1):277-298

The results of a survey searching for outflows using near-infrared imaging are presented. Targets were chosen from a compiled list of massive young stellar objects associated with methanol masers in linear distributions. Presently, it is a widely held belief that these methanol masers are found in (and delineate) circumstellar accretion discs around massive stars. If this scenario is correct, one way to test the disc hypothesis is to search for outflows perpendicular to the methanol maser distributions. The main objective of the survey was to obtain wide-field near-infrared images of the sites of linearly distributed methanol masers using a narrow-band 2.12-μm filter. This filter is centred on the  H₂ v = 1–0 S(1)  line; a shock diagnostic that has been shown to successfully trace CO outflows from young stellar objects. 28 sources in total were imaged of which 18 sources display H₂ emission. Of these, only two sources showed emission found to be dominantly perpendicular to the methanol maser distribution. Surprisingly, the H₂ emission in these fields is not distributed randomly, but instead the majority of sources are found to have H₂ emission dominantly parallel to their distribution of methanol masers. These results seriously question the hypothesis that methanol masers exist in circumstellar discs. The possibility that linearly distributed methanol masers are instead directly associated with outflows is discussed.  相似文献   

The continuum and narrow-line region of the narrow-line Seyfert 1 galaxy Mrk 766     

A. Rodríguez-Ardila †  M. Contini  S. M. Viegas 《Monthly notices of the Royal Astronomical Society》2005,357(1):220-234

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Hydrated sulphuric acid in dense molecular clouds     

Flavio Scappini  Cesare Cecchi-Pestellini  Harvey Smith  William Klemperer  Alexander Dalgarno 《Monthly notices of the Royal Astronomical Society》2003,341(2):657-661

We consider sulphur depletion in dense molecular clouds, and suggest hydrated sulphuric acid, H₂SO₄ ·  n H₂O, as a component of interstellar dust in icy mantles. We discuss the formation of hydrated sulphuric acid in collapsing clouds and its instability in heated regions in terms of the existing hot core models and observations. We also show that some features of the infrared spectrum of hydrated sulphuric acid have correspondence in the observed spectra of young stellar objects.  相似文献   

Modelling infrared galaxy evolution using a phenomenological approach     

G. Lagache  H. Dole  J.-L. Puget 《Monthly notices of the Royal Astronomical Society》2003,338(3):555-571

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The impact of broad mid-infrared emission bands on extragalactic surveys – a case study: the unidentified 22-μm feature     

Chris P. Pearson  K.-W. Chan  T. Onaka 《Monthly notices of the Royal Astronomical Society》2004,350(2):473-484

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The Orion nebula (M42) Herbig–Haro object, HH 201, within the tip of a molecular finger     

M. F. Graham  J. Meaburn  M. P. Redman 《Monthly notices of the Royal Astronomical Society》2003,343(2):419-426

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