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91.
Harpacticoida taxocen diversity in the silty-sandy littoral zone of Kandalaksha Bay of the White Sea
E. S. Chertoprud M. V. Chertoprud D. V. Kondar P. N. Kornev A. A. Udalov 《Oceanology》2006,46(4):492-500
The fauna composition, ecological groups, and life forms of Harpacticoids of soft littoral grounds from 15 sites off the Karelian coast in Kandalaksha Bay of the White Sea were studied. Six types of harpacticoid taxocens with different sets of dominating species are described. On silty sands with clear signs of desalination, the Stenchelia palustris taxocen is common; medium-grained sands are characterized by the Heterolaophonte minuta, Paraleptastacus kliei — Huntemannia jadensis, and Amphiascoides nanus — Scottopsyllus minor taxocens; while on coarse sands, the Ameira parvula and Ameira scotti — Mesochra lilljeborgi taxocens have developed. The diversity of the taxocens is partly explained by the differences in the grain-size composition and salinity at different sites. In addition, groups of various taxocens dwelling on the same type of the sediments were found in different minor bights of the coastline. 相似文献
92.
The wadic project: A comprehensive field evaluation of directional wave instrumentation 总被引:1,自引:0,他引:1
J. Allender T. Audunson S. F. Barstow S. Bjerken H. E. Krogstad P. Steinbakke L. Vartdal L. E. Borgman C. Graham 《Ocean Engineering》1989,16(5-6)
The results of a comprehensive field trial of nearly all commercially available directional wave measurement systems at the Edda field in the North Sea during winter 1985-86 are presented. The results summarize the accuracy of the principal engineering wave parameters from each system and the dependence on sea state. Limiting factors on system performance and operational problems are also included in the assessment. Overall experience has been good with systems utilizing widely different measurement principles returning consistent results. 相似文献
93.
The authors describe the effect of copper pollution on the mitochondria from various areas of the Torpedo marmorata central nervous system. A high percentage of swollen mitochondria has been observed in neurons from animals experimentally exposed to high level of copper (4 ppm). The correlation with age pigment granules is discussed. 相似文献
94.
The photochemical instability of several related pteridines in seawater was investigated by aseptic incubation of solutions at 20–22°C under illumination from cool-white light of intensity 6 kerg cm−2 sec−1, and the chemical changes were spectrophotometrically monitored. All the pteridines showed markedly accelerated degradation from this illumination relative to their behaviour in total darkness.Pterin and lumazine were degraded very slowly with zero-order reaction kinetics, while the other pteridines photolysed rapidly (according to first-order kinetics) with decomposition rates increasing in the order dioxylumazine (2,4,6,7-tetrahydroxypteridine) < leucopterin < isoxanthopterin < xanthopterin < oxylumazine (2,4,6-trihydroxypteridine). Excepting leucopterin and dioxylumazine, the photolysis rates were attributable to the pH of seawater and not its salt content; this was also the case with oxylumazine which required the salt content of seawater for decomposition in darkness. Leucopterin and dioxylumazine (both 6,7-dihydroxylated pteridines) gave evidence of complexation with the major divalent cations (Ca2+, Mg2+) of seawater, by virtue of which their photolytic degradation rates were enhanced to magnitudes obtained in pH-10 buffer without seawater. It is proposed that such complexation produces structural forms of these pteridines analogous to their normal ionic forms at pH 10–12.The photolysis of the 6-hydroxylated pteridines (xanthopterin, oxylumazine) proceeded via intermediate formation of their corresponding 7-hydroxylated derivatives (leucopterin, dioxylumazine). 相似文献
95.
96.
In this paper the peculiarities of compiled oceanographic data sets, which consist primarily in the presence of some characteristic information as well as in the planned incomplete filling of the files with observations, are discussed. A number of special ways are suggested which essentially improve the packing density of computerized data without applying special archiving algorithms. The effectiveness of these methods has been tested by treating thein situ hydrological/chemical data file compiled in the Black Sea in 1988.Translated by Vladimir A. Puchkin. 相似文献
97.
M. V. Ramana 《Geo-Marine Letters》1986,6(1):1-5
Satellite imagery and offshore magnetic data were analysed to correlate regional tectonic elements on the inner continental
shelf off Konkan and the adjacent Deccan plateau. Three statistically important lineament trends—N-S, WNW-ESE and ENE-WSW—that
prevail on land are correlatable well with the offshore trends. This positive correlation suggests simultaneous deformation.
The major magnetic lineament observed off Jaigad Bay, west coast of India, may be the extension of onshore lineaments. The
correlation of both the offshore and onshore trends indicates that the fracture pattern of the crystalline basement has also
controlled the offshore structural pattern. 相似文献
98.
Trends in emigration from Ireland over time are reviewed. "During the eighteenth and nineteenth centuries overseas migration to the United States and seasonal harvest migration to Britain were the main types of movement, but over the past 100 years the Irish have developed a special affinity for settling in British towns. Although the outflow was halted for a time during the 1970s, when return migration took over, the 1980s have seen a renewal of the exodus. This time, however, the character of the flow has changed from predominantly low-skill construction and factory workers to embrace better-educated emigrants, including many graduates. This shift reflects Ireland's changing position in the international market for labour." 相似文献
99.
Veeder GJ Hanner MS Matson DL Tedesco EF Lebofsky LA Tokunaga AT 《The Astronomical journal》1989,97(4):1211-1219
We report 10 micrometers infrared photometry for 22 Aten, Apollo, and Amor asteroids. Thermal models are used to derive the corresponding radiometric albedos and diameters. Several of these asteroids appear to have surfaces of relatively high thermal inertia due to the exposure of bare rock or a coarse regolith. The Apollo asteroid 3103, 1982 BB, is recognized as class E. The Jupiter-crossing Amor asteroid 3552, 1983 SA, is confirmed as class D, but low albedos remain rare for near-Earth asteroids. 相似文献
100.
The zonal structure of the distribution of filaments is considered. The mean latitudes of two filament bands are calculated in each solar hemisphere at the minima of the sunspot cycle in the period 1924–1986: middle latitude
2, m
and low latitude
1, m
. It is shown that the mean latitude of the filament band
2, m
at the minimum -m of the cycle correlates, with = 0.94, with the maximum - M sunspot area S(M) and maximum Wolf number W(M) in the succeeding solar cycle M. It is shown that the mean latitude of the low-latitude filament band
1, m
is linearly dependent on the mean latitude filament band
2, m + 1 at the succeeding minimum. We found a correlation of the latitude of the low-latitude filament band
1, m
with the maximum sunspot area in the M + 1 cycle. This enables us to predict the power of two succeeding 11-year solar cycles on the basis of the latitude of filament bands at the minimum of activity, 1985–1986: W(22) - 205 ± 10, W(23) - 210 ± 10. The importance of the relationships found for theory and applied aspects is emphasized. An attempt is made to interpret the relationships physically. 相似文献