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101.
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   
102.
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   
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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   
105.
The build-up of pore-water pressure by waves can lead to sediment liquefaction and subsequent transport by traction currents. This process was investigated by measuring pore-water pressures both in a field experiment and laboratory wave tank tests. Liquefaction was observed in the wave tank tests. The results suggest that sand is less susceptible than silts to wave-induced liquefaction because of the tendency to partially dissipate pore-water pressures. However, previous studies have determined that pore-water pressures must approach liquefaction before current velocities necessary to initiate transport are reduced. Once liquefaction has occurred more sediment can be transported.  相似文献   
106.
107.
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   
108.
109.
The American whaling industry rose from humble beginnings off Long island to become an international giant. In its peak year, 1846, 735 ships and 70,000 people served the industry. As whale stocks and reserves decreased, whalers were forced to go farther and farther from their New England home ports. Voyages became longer, and risks on required return-on-investment became higher. The easy money of Atlantic and Pacific whaling was no more: the only remaining profitable ventures were to Arctic and Antarctic waters. Many ships returned empty, if at all. in 1871, most of the Arctic whaling fleet was crushed by early winter ice and lost. This calamity, in conjunction with the long-term diminishing whale stocks, the diversion of investment capital to more profitable ventures, and the discovery, development, and refinement of abundant petroleum crude oil, struck the death blow to the American whaling industry. By 1890, only 200 whaling vessels were at work, and by 1971, no American commercial whaling ship sailed the world's oceans.It is apparent that no single event caused the final, rapid decline. However, a single calamity, in an already stressed industry, that was self-insured and commercially interlinked, precipitated the end. Today's American petroleum industry, although adopting some principles of the American whaling industry, also has embraced other activities such as work process reengineering and customer alliances, which may preempt, or postpone, a similar catastrophic demise.  相似文献   
110.
Newtonian cosmology is developed with the assumption that the gravitational constantG diminishes with time. The functional form adopted forG(t), a modification of a suggestion of Dirac, isG=A(k+t) –1, wheret is the age of the Universe and a small constantk is inserted to avoid a singularity in the two-body problem. IfR is the scale factor, normalized to unity at an epoch time , the differential equation is then . Here 0 is the mean density at the epoch time. With the above form forG(t), the solution is reducible to quadratures.The scale factorR either increases indefinitely or has one and only one maximum. LetH 0 be the present value of Hubble's constant /R and 0c the minimum density for a maximum ofR, i.e., for closure of the Universe. The conditions for a maximum lead to a boundary curve of 0c versusH 0 and the numbers indicate strongly that thisG-variable Newtonian model corresponds to an open universe. An upward estimate of the age of the Universe from 1010 yr to five times such a value would still lead to the same conclusion.The present Newtonian cosmology appears to refute the statement, sometimes made, that the Dirac model forG necessarily leads to the conclusion that the age of the Universe is one-third the Hubble time. Appendix B treats this point, explaining that this incorrect conclusion arises from using all the assumptions in Dirac (1938). The present paper uses only Dirac's final result, viz,G(k+t)–1, superposing it on the differential equation .  相似文献   
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