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  • 1990-1994  (18)
  • 11
    Electronic Resource
    Electronic Resource
    Electron transport across a wide AlGaAs barrier (1993)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 5606-5621 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An experimental and theoretical study has been made of electron transport over a wide AlGaAs barrier with graded interfaces sandwiched between GaAs contact layers. The width of the central barrier region was varied between 700 and 2100 A(ring). Two series of samples with nominally identical structures but from different sources were investigated. Extensive measurements of both the voltage and temperature dependence of the current were made, as well as measurements of capacitance and magnetoresistance. Drift-diffusion thermionic emission theory has been used to interpret the data. Both numerical and analytical solutions of the model have been developed and were found to be in good agreement with each other. The presence of space charge in the barrier region, which has the effect of increasing the barrier height, was seen to be crucial to an understanding of the data. When the effect of space charge was included in the model good agreement was obtained between theory and experiment for electric fields up to 10 kV cm−1. The numerical solution required only one adjustable parameter, namely the value of the space-charge density. The parameters used in the analytical model were all derived from the experimental data.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.354222
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    Paper (German National Licenses)
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  • 12
    Electronic Resource
    Electronic Resource
    Relationship between rod catches and distribution of adult Atlantic salmon, Salmo salar L., during the initial phase of riverine migration (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 24 (1993), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.1993.tb00644.x
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    Paper (German National Licenses)
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  • 13
    Electronic Resource
    Electronic Resource
    Recent trends in the rod catches of Atlantic salmon, Salmo salar L., from four sites on the River Spey (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture research 24 (1993), S. 0 
    Details
    ISSN: 1365-2109
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. Rod catches at four sites on the River Spey were analysed over the period 1970–1991. The year-by-year trends and seasonal patterns of rod catches varied according to site location. During the 1970s and 1980s the spring salmon catch from the Spey as a whole declined, mirroring a decline in catch at the lower sites in the river early in the year. Catches at the study sites did not always follow trends in the fishery as a whole, however, illustrating that the catch at any given site is not a simple function of the total number of available fish in the river. In the first 2 years of the 1990s the decline in early season catches continued, accompanied by a more general drop in catches throughout the angling season at three out of four sites.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1365-2109.1993.tb00643.x
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    Paper (German National Licenses)
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  • 14
    Electronic Resource
    Electronic Resource
    The relationship between river flow and entry to the Aberdeenshire Dee by returning adult Atlantic salmon (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 45 (1994), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: One hundred and nine returning adult salmon were radio-tagged in the estuary of the Aberdeenshire Dee, Scotland between February and August 1985 to 1989 and the times when 62 fish entered the river were recorded. Elapsed times between tagging and river entry were significantly greater during periods of lower than average river flows in all months where there were sufficient data to allow statistical comparison. The degree of association between river entry and particular levels of river discharge rate varied seasonally. The proportion of days associated with river entry declined at the lower end of the range of flows available to tagged fish in the summer months. Absolute levels of river discharge played a significant role in modifying the response of salmon to changing flows. During periods of lower than average seasonal flow, river entry was closely associated with days when flow had increased since the previous day. During periods of higher than average flow, river entry was not significantly associated with such periods of increased flow. The results suggest that models which relate river entry by salmon to absolute discharge rates alone are unlikely to be generally reliable.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1994.tb01065.x
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    Paper (German National Licenses)
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  • 15
    Electronic Resource
    Electronic Resource
    A comparison of the movements of two species of gadoid in the vicinity of an underwater reef (1994)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 45 (1994), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Two saithe (35 and 38 cm) and two pollack (43 and 44 cm) were tracked simultaneously for 170 h. During the day, saithe generally patrolled over the whole of an underwater reef as part of a school, making occasional excursions off the reef to another smaller reef 250m distant. At night, saithe movements were largely limited to the reef. Pollack covered less than 50% of the reef during the study period, moving only small distances off the reef. Pollack swam more slowly than saithe during the day, but at the same speed at night.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1994.tb00946.x
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    Paper (German National Licenses)
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  • 16
    Electronic Resource
    Electronic Resource
    Diurnal patterns in the spatial relationships between saithe, Pollachius virens, schooling in the wild (1993)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 43 (1993), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Six saithe, length 35 to 43 cm, were tagged with acoustic transmitters and individuals tracked for between 9 and 508 h during May 1989. The tagged fish were members of a schooling group and during the study, pairs of tagged fish were tracked simultaneously for periods ranging from 9 to 139 h. These data have been used to investigate the spatial relationships between individuals schooling in the wild. Distances between individuals showed a distinct diel pattern. Tagged fish were generally closer together during the day, than either at night or the periods of dawn and dusk. Those circumstances under which pairs of tagged fish could be shown to school together were investigated by analysing the differences in their swimming directions. Schooling was generally evident during the hours of daylight, although the degree to which fish schooled varied between pairs. The degree to which the fish schooled was also dependent upon distance between the tagged individuals. Schooling could be demonstrated for saithe within 20 m of each other during the day and within 10 m in two out of three pairs at night.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1993.tb01195.x
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    Paper (German National Licenses)
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  • 17
    Electronic Resource
    Electronic Resource
    Residence time of the sea louse, Lepeophtheirus salmonis K., on Atlantic salmon, Salmo salar L., after immersion in fresh water (1990)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 37 (1990), S. 0 
    Details
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Returning adult salmon caught at the mouth of the River Dee, Aberdeenshire, were transferred to tanks in the laboratory. For fish placed in fresh water, sea lice remained attached for up to 6 days, though most lice were lost in the first 48 hours. Few lice were lost from salmon maintained in sea water. The experiments were conducted in water within a temperature range of 12·8 to 16° C, equivalent to summer river temperatures in the Aberdeenshire Dee.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1095-8649.1990.tb05861.x
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    Paper (German National Licenses)
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  • 18
    Electronic Resource
    Electronic Resource
    X-ray crystal and molecular structure of dichlorobis [2(1H)-pyridinethione-S]iron(II) (1991)
    Springer
    Journal of chemical crystallography 21 (1991), S. 9-12 
    Details
    ISSN: 1572-8854
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Attempts to prepare the mixed ligand complex, FeCl2(pyS)(Ph3P)2 from the reaction of iron(III) chloride with 2(1H)-pyridinethione-S(HpyS) and triphenylphosphine(Ph3P) in ethanol instead formed FeCl2(HPyS)2 characterized by X-ray crystallography. The structure was determined by the heavy atom method, using MoKα diffractometer data, and refined by full-matrix least squares toR=0.049 for 1123 observed reflections. The molecule possesses twofold symmetry with a distorted tetrahedral geometry about the iron(II) center with S-Fe-S and Cl-Fe-Cl bond angles of 98.76(5)° and 115.79(5)° and Fe-S and Fe-Cl bond distances 2.345(1) Å and 2.288(1) Å, respectively. Hydrogen bonding between NH and chlorine atoms leads to a polymeric type structure of linked molecules running approximately parallel to thea axis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01158967
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    Paper (German National Licenses)
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