黄、渤海漂移浒苔(Enteromorpha prolifera)脂肪酸组成及聚类分析的研究     

杨佰娟  郑立  陈军辉  臧家业  王小如  黎先春 《海洋与湖沼》2009,40(5):627-632

于2008年7月在黄、渤海区域采集了17个漂移浒苔样品,结合3个本地种,对其脂肪酸组成进行了GC-MS分析。结果表明,所有浒苔中优势脂肪酸为十六碳酸,相对含量在27.82%—43.27%之间。藻体中还含有丰富的PUFA,主要为9,12,15-十八碳三烯酸、6,9,12-十八碳三烯酸、9,12-十八碳二烯酸、8,11,14-二十碳三烯酸,另外还含有EPA不饱和脂肪酸。以欧式距离平方为距离测量技术,类间距用平均链锁法,对20个不同地理位置的浒苔样品进行聚类分析,结果分为4大类,所有漂浮浒苔聚为第一类,青岛和连云港的本地种分别聚为另三类,说明青岛近海漂浮的浒苔不是青岛本地生浒苔,而是从外海漂移过来的,第一类的聚类结果显示了浒苔的漂移路径。结果表明,藻类脂肪酸的系统聚类分析为海洋绿藻分类与量化评价提供了一种好方法。  相似文献   

REGIONAL GROWTH AND REGIONAL PROBLEMS UNDER CAPITALISM     

FRANK HANSEN M.Sc. 《Geografisk tidskrift / udgivet af Bestyrelsen for Det Kongelige danske geografiske selskab》2013,113(1):109-113

Hansen, Frank: Regional growth and regional problems under capitalism—two connected types of analyses? Geografisk Tidsskrift 80: 109–113. Copenhagen, June 1980.

Marxistic regional analyses are criticized for having focussed one-sidedly on the localization of capital and labour and neglected the human and environmental consequences of the capital's movements and localization. On the basis hereof a localization analysis is outlined as also an analysis of the regional differences in labour's working and reproduction conditions, and it is discussed how these differences and the localization of capital influence each other.  相似文献   

Simulation of the transport of Rn²²² using on-line and off-line global models at different horizontal resolutions: a detailed comparison with measurements,     

FRANK DENTENER  JOHANN FEICHTER  AD JEUKEN 《Tellus. Series B, Chemical and physical meteorology》1999,51(3):573-602

  相似文献   

A first-order analysis of the potential rôle of CO₂ fertilization to affect the global carbon budget: a comparison of four terrestrial biosphere models     

DAVID W. KICKLIGHTER  MICHELE BRUNO  SILKE DÖNGES  GERD ESSER  MARTIN HEIMANN  JOHN HELFRICH  FRANK IFT  FORTUNAT JOOS  JÖRG KADUK  GUNDOLF H. KOHLMAIER  A. DAVID McGUIRE  JERRY M. MELILLO  ROBERT MEYER  BERRIEN MOORE III  REAS NADLER  I. COLIN PRENTICE  WALTER SAUF  ANNETTE L. SCHLOSS  STEPHEN SITCH  UWE WITTENBERG  GUDRUN WÜRTH 《Tellus. Series B, Chemical and physical meteorology》1999,51(2):343-366

  相似文献   

20th century tree‐line advance and vegetation changes along an altitudinal transect in the Putorana Mountains,northern Siberia     

ALEXANDER V. KIRDYANOV  FRANK HAGEDORN  ANASTASIA A. KNORRE  ELENA V. FEDOTOVA  EUGENE A. VAGANOV  MUHTAR M. NAURZBAEV  PAVEL A. MOISEEV  ANDREAS RIGLING 《Boreas: An International Journal of Quaternary Research》2012,41(1):56-67

Kirdyanov, A. V., Hagedorn, F., Knorre, A. A., Fedotova, E. V., Vaganov, E. A., Naurzbaev, M. M., Moiseev, P. A. & Rigling, A. 2012 (January): 20th century tree‐line advance and vegetation changes along an altitudinal transect in the Putorana Mountains, northern Siberia. Boreas, Vol. 41, pp. 56–67. 10.1111/j.1502‐3885.2011.00214.x. ISSN 0300‐9483. Ongoing climatic changes potentially affect tree‐line ecosystems, but in many regions the observed changes are superimposed by human activities. We assessed how the forest‐tundra ecotone has changed during the last century in the Putorana Mountains, northern Siberia, an extremely remote and untouched area in Eurasia. A space‐for‐time approach was used to determine the spatio‐temporal dynamics of forest structure and biomass along an altitudinal transect. From the closed larch forest to the upper tree line, the mean age of Larix gmelinii (Rupr.) decreased considerably from 220 to 50 years ago. At the current upper species line, there is a strong and successful germination of larch, with 1500 saplings per hectare, indicating an ongoing filling‐in, a densification of a formerly open forest and an upslope shift of the tree‐line position (approximately 30 to 50 m in altitude during the last century). The forest expansion coincided with large increases in winter precipitation during the 20th century. In contrast, tree growth rates were significantly positively related to summer temperatures, neither of which increased markedly. The total aboveground biomass decreased from approximately 40 t ha^?1 in the closed larch forest to 5 t ha^?1 at the tree line. Our study demonstrates that ongoing climatic changes lead to an upslope expansion of forests in the remote Putorana Mountains, which alters the stand structure and productivity of the forest‐tundra ecotone. These vegetation changes are very probably of minor importance for aboveground carbon sequestration, but soil carbon data are needed to estimate the impact of the forest expansion on the total ecosystem carbon storage.  相似文献   

Ferdynandovian Interglacial climate reconstructions from pollen successions, stable-isotope composition and magnetic susceptibility     

DARILJSZ KRZYSZKOWSKI  TATJANA BÖTTGER  FRANK W. JUNGE  TERESA KUSZELL  JERZY NAWROCKI 《Boreas: An International Journal of Quaternary Research》1996,25(4):283-296

The Ferdynandovian Interglacial is one of the most controversial Quaternary stratigraphic horizons in Europe. This study concentrates on palaeoclimatic reconstruction of this interglacial based on pollen succession, isotope composition and magnetic susceptibility. The section investigated is located in the open cast mine at Belchatow, central Poland. The lacustrine sequence contains laminated diatomite at the base, which was deposited in deep, meromictic lake, and massive diatomite to calcareous gyttja in its upper part. The latter were deposited in a holomictic lake, which became progressively more shallow. The gradual increase of δ¹⁸O values and simultaneous decrease of susceptibility in the lower part of the Ferdynandovian sequence at Belchatow correspond well with climatic amelioration documented by pollen analysis. Simultaneous increase of precipitation of carbonates and its δ¹³C values correspond well with the increase in biological activity in the lake. Results obtained by isotope investigations showed an increase in the mean annual temperature to a maximum of 7.5°C from the beginning of the interglacial to the first appearance of thermophilous, deciduous trees. The oxygen-isotope curve does not show any short-term climatic oscillations. Susceptibility oscillations are somewhat more distinct, but because the main magnetic carrier is greigite deposited on spores of unicellular organisms, they are linked to the concentration of these spores rather than with the climatic oscillations. Twelve secular cycles or their fragments have been recorded in the interglacial sequence by palaeomagnetic investigations, suggesting c . 9600 years of deposition. This corresponds well with the 10 000 years of deposition calculated for the same sequence based on annually laminated diatomites.  相似文献   

Toward a model for airflow on the lee side of aeolian dunes   总被引：8，自引：0，他引：8  

ANDREW FRANK  GARY KOCUREK 《Sedimentology》1996,43(3):451-458

The interaction between dunes and the primary wind results in a complex pattern of secondary airflow on the lee side of dunes. From 15 dunes studied during transverse flow conditions at Padre Island in Texas, White Sands in New Mexico, and the Algodones in California, distinct flow regions can generally be recognized, with the overall flow structure comparing favourably to that proposed for subaqueous bedforms. Downwind of dunes with flow separation is a back-flow eddy that extends about four dune-brink heights downwind from the brink of the dune. Beyond the separation cell, the velocity profiles can be divided into regions based upon segments separated by ‘kinks’ in the velocity profiles. The interior is an area above the dunes of relative high wind speed but low velocity gradient. Beneath the interior is the wake, which consists of two layers. The upper wake exhibits an uppermost portion where the flow decelerates while the remainder exhibits accelerating flow, so that the overall velocity gradient decreases downwind. The lower wake exhibits low velocity gradients and wind speeds that accelerate downwind at all heights, but primarily near the top of the layer, thereby causing the velocity gradient to increase downwind. At about eight dune heights downwind, the upper and lower wakes equilibrate to a single profile with the kink between them no longer apparent. The lowest recognizable region is the internal boundary layer. It is recognized by a relatively steep velocity gradient below the wake, and never exceeds a few tens of centimetres in height for our data set. Because of acceleration and increasing shear stress within this layer, interdune flats are at least potentially erosional. Overall, the wake and internal boundary layer show a downward transfer of momentum from upper regions so that the flow recovers. Where flow separation does not occur, simple flow expansion down the lee-face causes flow deceleration.  相似文献   

Prograde and Retrograde Evolution in High-temperature Corundum Granulites (FMAS and KFMASH Systems) from In Ouzzal Terrane (NW Hoggar, Algeria)   总被引：5，自引：5，他引：5  

OUZEGANE  K.; GUIRAUD  M.; KIENAST  J. R. 《Journal of Petrology》2003,44(3):517-545

The mineralogy and phase relationships of corundum-bearing granulitesfrom In Ouzzal (Hoggar, Algeria) are analysed within the contextof the present knowledge of In Ouzzal metamorphism, as independentlydeduced from quartz-bearing rocks: a clockwise evolution characterizedby peak temperatures ranging from 850°C to more than 1100°Cat about 10 kbar, followed by decompression and cooling to about5 kbar and 750°C. The corundum-bearing rocks have been dividedinto three types (A–B, C and D) according to their mineralogy.Type A–B is characterized by the occurrence of sapphirine–sillimanite–orthopyroxene–phlogopitewith or without garnet, Type C by the occurrence of spinel–sapphirine–garnet,and Type D by the occurrence of garnet–spinel–sillimanite.Thermodynamic data for sapphirine have been adjusted from thecurrent THERMOCALC dataset to fit in with available experimentaldata and current theoretical phase diagrams. MAS, KMASH, FMASand KFMASH petrogenetic grids that connect quartz-present andcorundum-present grids are presented. Pseudosections derivedfrom these grids account well for the observed textures. Thethree types of rock agree with the decompression path experiencedby the quartz-bearing rocks. The occurrence of sapphirine correspondsto peak and decompression conditions, and trends of sapphirineand orthopyroxene compositions are consistent with this evolution. KEY WORDS: corundum; In Ouzzal; sapphirine; UHT metamorphism  相似文献   

Kilauea East Rift Zone Magmatism: an Episode 54 Perspective   总被引：1，自引：0，他引：1  

THORNBER  CARL R.; HELIKER  CHRISTINA; SHERROD  DAVID R.; KAUAHIKAUA  JAMES P.; MIKLIUS  ASTA; OKUBO  PAUL G.; TRUSDELL  FRANK A.; BUDAHN  JAMES R.; RIDLEY  W. IAN; MEEKER  GREGORY P. 《Journal of Petrology》2003,44(9):1525-1559

On January 29–30, 1997, prolonged steady-state effusionof lava from Pu'u'O'o was briefly disrupted by shallow extensionbeneath Napau Crater, 1–4 km uprift of the active Kilaueavent. A 23-h-long eruption (episode 54) ensued from fissuresthat were overlapping or en echelon with eruptive fissures formedduring episode 1 in 1983 and those of earlier rift zone eruptionsin 1963 and 1968. Combined geophysical and petrologic data forthe 1994–1999 eruptive interval, including episode 54,reveal a variety of shallow magmatic conditions that persistin association with prolonged rift zone eruption. Near-ventlava samples document a significant range in composition, temperatureand crystallinity of pre-eruptive magma. As supported by phenocryst–liquidrelations and Kilauea mineral thermometers established herein,the rift zone extension that led to episode 54 resulted in mixtureof near-cotectic magma with discrete magma bodies cooled to  相似文献   

极点和零点 ——数字地震学基础(英文，待续)     

FRANK SCHERBAUM  徐扬  丁学文 《山西地震》2001,(1):39-48

地震学中的一个主要问题是如何将原始的震源信号从其他影响中分离出来。讨论了地震波在传播过程中可能引起波形变化的一些因素以及记录系统和采样处理过程所产生的影响，介绍了地震信号处理中的一般原理和概念，通过对简单的RC滤波器的讨论，揭示了系统理论的一些基本概念，如线性时间不变系统、傅里叶变换和拉普拉斯变换、褶积、频率响应函数、传递函数和极点等，为讨论数字地震信号的处理奠定了基础。  相似文献