Local co-operation, ethnic diversity and state territoriality – The case of Haparanda and Tornio on the Sweden – Finland border     

Thomas Lundén  Dennis Zalamans 《GeoJournal》2001,54(1):33-42

The neighbouring towns of Haparanda and Tornio, separated only by a narrow strip of grass and wetland, are divided by the only inhabited land boundary between Finland and Sweden in the southern part of the Torne River. The population represents four different groups in relation to linguistic and cultural backgrounds. In the daily lives of the inhabitants, the state boundary is probably of less significance than linguistic, social and ‘ethnic’ differences. On the local government level there is a strong will to unite forces to make the total area a viable region in spite of its peripheral location, but state legislation makes co-ordination difficult. This may be seen as a necessity, but in the daily lives of the populations, the state boundary defines an area of unequal access, sometimes working in favour of and sometimes barring contacts and co-operation. The media consumption reflects a clear ‘national’ interest with a strong local bias. In their attitudes, Finnish speakers and bilinguals show a greater appreciation of ‘the other’ than unilingual Swedes. This may reflect the actual possibility space (reach) in the local area. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Evolution of Pangea: paleomagnetic constraints from the Southern Alps, Italy     

Giovanni Muttoni  Dennis V. Kent  James E.T. Channell 《Earth and Planetary Science Letters》1996,140(1-4):97-112

A new early Late Triassic paleopole for Adria has been obtained from the Val Sabbia Sandstone in the Southern Alps. As Early Permian and Jurassic-Cretaceous paleomagnetic data from para-autochthonous regions of Adria such as the Southern Alps are consistent with ‘African’ APWPs[1–2], paleomagnetic data from this region can be used to bolster the West Gondwana APWP in the poorly known Late Permian-Triassic time interval. The Southern Alpine paleopoles are integrated with the West Gondwana and Laurussia APWPs of Van der Voo [1] and used to generate a tectonic model for the evolution of Pangea. The Early Permian overall mean paleopole for West Gondwana and Adria, in conjunction with the coeval Laurussia paleopole, support Pangea B of Morel and Irving [3]. The Late Permian/Early Triassic and the Middle/Late Triassic paleopoles from Adria and Laurussia support Pangea A-2 of Van der Voo and French [4]. The phase of transcurrent motion between Laurasia and Gondwana[5] that caused the Pangea B to A-2 transition occurred essentially in the Permian (at the end of Variscan orogeny) with an average relative velocity of approximately 10 cm/yr. Finally, the Late Triassic/Early Jurassic paleopoles from West Gondwana and Laurussia agree with Pangea A-1 of Bullard et al. [6], the widely accepted Pangea configuration at the time of the Jurassic breakup.  相似文献   

A Controlled Field Test of Surfactant-Enhanced Aquifer Remediation   总被引：4，自引：0，他引：4  

John C. Fountain  Robert C. Starr  Thomas Middleton  Michael Beikirch  Craig Taylor  Dennis Hodge 《Ground water》1996,34(5):910-916

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Zooplankton dynamics in an intertidal salt-marsh basin     

Dorian S. Houser  Dennis M. Allen 《Estuaries and Coasts》1996,19(3):659-673

We determined tidal, diel (day-night), and diurnal (day to day) patterns of occurrence for the summer zooplankton assemblage in an intertidal salt marsh basin at North Inlet Estuary, South Carolina. In one time series, 153 μm pump and 365 μm net collections were made every 1–2 h during four consecutive tidal cycles. Taxonomic composition remained unchanged throughout most of the 48-h period, but densities and proportionalities of individual taxa were highly variable. Recurring patterns of abundance were observed and taxon-specific relationships with the tidal and diel cycles were indicated. Zooplankton were not uniformly distributed within flooding-ebbing water masses and distributions could not be explained by simple passive advection with the tides. Diel differences in densities of copepods and bivalves resulted from behavioral responses to changing light conditions. Large pulses of crab and shrimp larvae originating from nocturnal hatching events within the intertidal basin exited but did not return during the next flood tide. Higher densities of postlarval decapods on flood tides indicated settlement and recruitment to the shallow basin. In a second time series, replicated collections of the 153 μm and 365 μm assemblages were made during the daytime ebb tide every 1–3 d from May through October 1991 to determine relationships between diurnal changes in depth, salinity, and temperature and zooplankton composition and abundance. Diurnal variations in densities and proportionalities were less than those observed during the 48-h study and patterns were not regular. For most taxa, relationships between depth and abundance were the same in both time series. During periods of reduced salinity, densities of copepods,Uca zoeae, and barnacle nauplii decreased and densities ofUca megalopae andPenaeus postlarvae increased. However, zoeae emerged and postlarvae recruited throughout the 5-mo period, indicating that considerable flexibility in responses and tolerances existed within the populations. The diversity of life-history strategies and behavioral adaptations found among the zooplankton assures continuous occupation of flooded intertidal habitats. We suspect that the evolution and maintenance of temporally staggered recurring patterns of occurrence results in reductions in the competition for resources.  相似文献   

Lower palaeozoic and precambrian petroleum source rocks and the coalification path of alginite     

Miryam Glikson  Dennis Taylor  Douglas Morris 《Organic Geochemistry》1992,18(6)

Organic-rich samples derived from a Middle Cambrian Formation in the Georgina Basin, and from the Middle Proterozoic of the McArthur Basin in northern and central Australia, yielded alginite ranging from immature oil shale material to overmature residue. A maturation scale has been developed based on the thermal evolution of alginite as determined from reflectance and fluorescence. The coalification path of alginite is marked by jumps in contrast to the linear path of wood-derived vitrinite. Six zones have been recognised, ranging from undermature (zone I), through the mature (zones II/III), followed by a stable stage of no change (zone IV) to the overmature (zones V and VI). The onset of oil generation in alginite as evident from the present study is at 0.3% R_{o Alg.} and is expressed in a change of fluorescence from yellow to brown, and a coalification jump from 0.3 to 0.6% R_o of Alg. In many boreholes zone III can be distinguished between 0.6 and 0.8% R_o of Alg. where subsequent oil generation occurs. Zones II and III represent the oil window.A zone of little or no change designated zone IV, at of alginite follows zones II/III. A marked coalification jump characterises zone V, where a pronounced change in reflectance occurs to >1.0% R_{o Alg.}, signifying peak gas generation. The border of oil preservation lies at the transition of zone V and VI, at 1.6% R_{o Alg.} In zone VI gas generation only occurs.Comparison of reflectance results with experimental and geochemical pyrolysis data supports high activation energies for hydrocarbon generation from alginite, and therefore a later onset of oil generation than other liptinite macerals (i.e. cutinite, exinite, resinite) as well as a narrow oil window.Transmission electron microscopy (TEM) confirms that alginite does not go through a distinct intermediate stage but that the percentage of unreacted organic matter decreases as maturation proceeds. A clear distinction can be made in TEM between immature alginite, alginite after oil generation, and alginite residue following gas generation. Alginite beyond 1.6% R_o acquires very high densities and the appearance of inertinite in TEM.Bitumens/pyrobitumens make a pronounced contribution to the organic matter throughout the basins and have been shown to effect pyrolysis results by suppressing T_max. The bitumens/pyrobitumens have been divided into four groups, based on their reflectance and morphology, which in turn appears to be an expression of their genetic history. Their significance is in aiding the understanding of the basins' thermal history, and the timing of oil and gas generation.  相似文献   

Zur genetischen Unterscheidung von gemeinen Klüften und Verschiebungen     

Prof. Dr. John G. Dennis 《International Journal of Earth Sciences》1969,59(1):222-228

Zusammenfassung Oft wird zwischen Klüften und Verschiebungen ein genetischer Zusammenhang gesehen. Neuere Untersuchungen lassen einen grundsätzlichen Unterschied erkennen: Die gemeinen Klüfte entstehen durch spröden Bruch im Anschluß an eine elastische Deformation; Verschiebungen und ihnen zugeordnete Klüfte gehen zumeist aus einer plastischen Deformation hervor. Auch sind Verschiebungen an begrenzte Zonen gebunden und meist gefügefremd, obwohl sie sich bestehenden Kluftsystemen anpassen können. Die Systeme der gemeinen Klüfte sind dagegen fast gleichmäßig auf weite Bereiche verteilt und passen sich dem bestehenden Gesteinsgefüge an. Zur Deutung der Bruchtektonik sollten deshalb klufttektonische Analysen nur mit äußerster Vorsicht herangezogen werden.

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Joints and faults are commonly regarded as genetically related. Recent investigations, however, tend to bring out a fundamental genetic distinction: Common joints form by brittle fracture following elastic deformation; faults result from ductile fracture. Moreover, faults and related joints are restricted to narrow zones and rarely conform with preexisting fabric, while common joints are regionally pervasive and are fabric controlled. When evaluating fracture analyses, therefore, the genetic distinction between common joints and faults must be borne in mind.

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Résumé On croit souvent devoir mettre en relation génétique joints et failles. Des études récentes permettent d'y voir une distinction. Les joints banaux proviennent d'une rupture cassante, à la suite d'une déformation élastique. Les failles suivent une rupture plastique. En plus, les failles et les joints qui leur sont apparentés sont restreints à des zones plus ou moins étroites et se conforment rarement à la structure interne de la roche, trandis que les joints banaux ont une distribution régionale, et sont liés à la structure interne. L'analyse des ruptures géologiques doit, par conséquent, tenir compte d'une distinction fondamentale entre joints banaux, et joints apparentés aux failles.

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A minimalistic approach for evapotranspiration estimation using the Prophet model     

A. T. M. Sakiur Rahman  Takahiro Hosono  Ozgur Kisi  Boateng Dennis  A. H. M. Rahmatullah Imon 《水文科学杂志》2020,65(12):1994-2006

ABSTRACT

This study aimed to evaluate the potential of the recently introduced Prophet model for estimating reference evapotranspiration (ETo). A comparative study was conducted for benchmarking the model results with support vector regression (SVR) and temperature-based empirical models (Thornthwaite and Hargreaves) in southern Japan. The performance of the Prophet, SVR and temperature-based empirical models was evaluated by Nash–Sutcliffe efficiency (NSE) and coefficient of determination (R²). The results indicate that temperature-based Prophet and SVR models have greater accuracy than the empirical models. The Prophet model with sole input of relative humidity, sunshine hours or windspeed showed acceptable accuracy (NSE > 0.80; R² > 0.80), while SVR models with similar inputs showed greater errors. Accuracy improved with increasing number of input parameters, giving excellent performance (NSE > 0.95; R² > 0.95) with all input parameters. Hence, the Prophet model is a new promising approach for modelling ETo with limited input variables.  相似文献   

Book reviews     

Werner Mikus  Lilla Zadory  Dennis Rumley  Dean Hegg  Risto Laulajainen 《GeoJournal》1983,7(6):570-572

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Extremal tides: rigorous computation for the many-body case     

Dennis Rawlins 《Geophysical Journal International》1982,69(1):265-271

Summary. A rigorous method is developed for the exact solution of the extrema of the total tidal field on a spherical celestial body, disturbed by a multiplicity of gravitating point masses distributed in three dimensions at distances large relative to the disturbed body's size. A short program is provided for convenient use of the method. As an illustration, maximal solar tides due to planetary attraction are calculated for the Solar System 1964–1991.  相似文献   

Paralytic shellfish toxins in green-lipped mussels,Perna viridis,in Hong Kong     

Mak KC  Li AM  Hsieh DP  Wong PS  Lam MH  Wu RS  Richardson BJ  Lam PK 《Marine pollution bulletin》2003,46(2):258-263

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