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31.
Octopus (Octopus vulgaris, Mollusca, Cephalopoda) is an important and valuable fishery resource on the eastern and southern coasts of Tunisia, but its landings are highly variable. This paper explores the effect of environment on octopus catch per unit effort (CPUE) during a 12‐year period, through correlation analyses and the incorporation into surplus production models of sea surface temperature (SST) and rainfall data collected during cold (January–May) and hot (August–October) seasons. CLIMPROD software was used to select the appropriate model and fit it to the fishery and environment data. In both seasons, SST significantly contributed to CPUE variability; fishery production was influenced positively by cold season SST but negatively by hot season SST. Due to a poor fit with cold season data, the impact of rainfall was analysed only for the hot season, during which it has a positive effect on production. Results are discussed in view of the life‐cycle of octopus and the dynamics of the Tunisian fishery. This first study of octopus variability in Tunisia highlights the necessity to incorporate environmental influence into stock assessment and management advice. 相似文献
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34.
Mag. Ch. Spötl 《Mineralogy and Petrology》1989,40(3):225-233
Summary Back-scattered electron imagery (BSE) coupled with energy-dispersive X-ray elemental analysis was applied to petrographic investigations of recrystallized, anchimetamorphic breunnerites (ferroan magnesites). Analyses of polished thin sections allowed the recognition of a complex zoning pattern, invisible by transmitted or reflected light microscopy. Breunnerite precipitation and replacement started with (Mg0.90Fe0.07Ca0.01Mn0.02) CO3 and proceeded towards (Mg0.73Fe0.22Ca0.00Mn0.05)CO3. This precipitation sequence was interrupted by at least two major events of reverse zoning (i.e. Fe-rich zones followed by Fe-poor ones). Resorption surfaces in Fe-poor zones are common and prove that short-term fluctuations occurred in the paleobrine composition and/or paleotemperature.
With 5 Figures 相似文献
Nachweis komplexer zonierung und resorption im breunnerit mittels Rückstreuelektronenbilder
Zusammenfassung Breunnerit-Proben von der Typlokalität evaporitischer Magnesitlagerstätten (ehemaliger Salzbergbau Hall in Tirol/Österreich) wurden an Hand von Rückstreuelektronen(BSE)-Bildern und energiedispersiven Röntgenanalysen (EDS) untersucht. Während Durch- und Auflichtmikroskopie lediglich eine zweiphasige Kristallisationsgeschichte erkennen ließen, konnte mittels BSE-Bildern eine detaillierte Rekonstruktion der spätdiagenetischen bzw. anchimetamorphen Breunneritbildung durchgeführt werden. Ein genereller Trend zu Fe-reicheren, häufig oszillierend-zonierter Mischkristalle der Reihe Magnesit-Siderit konnte erkannt werden, der jedoch von mindestens zwei invers zonierten Phasen unterbrochen wurde. Resorptionserscheinungen in den Fe-ärmeren Zonen sind verbreitet und belegen kurzfristige Fluktuationen in der Paläofluid-Zusammensetzung und/oder dessen Paläotemperatur.
With 5 Figures 相似文献
35.
A pilot plant study and a full scale plant study were conducted to determine the feasibility of using contact oxidation followed by activated carbon adsorption process in textile wastewater treatment, and to determine the effects of types of packing media in the contact oxidation tank and types of aeration process on the treatment performance. Results indicated that contact oxidation followed by activated carbon adsorption process was effective in removing organics and color from textile wastewaters. Types of packing media and types of aeration processes had little effect on the treatment performance. The pilot plant performance was found to perform slightly better than the performance of the full scale plant. 相似文献
36.
A. Piqué G. Bossière J. -P. Bouillin A. Chalouan Ch. Hoepffner 《International Journal of Earth Sciences》1993,82(3):432-439
Stratigraphic and structural correlations between the Palaeozoic massifs of eastern Morocco and northern Algeria allow three tectonic domains to be distinguished: (1) The cratonic zone, i.e. the West African platform which remained outside the Variscan chain and its peripherical margin (Moroccan Anti-Atlas and Algerian Ougarta); (2) a WSW-ENE trending zone, over 1500 km from Marrakech to Kabylia and Calabria (in their assumed Palaeozoic location). — This zone was characterized during the Late Palaeozoic by a continuous instability indicated by the development of successive turbiditic basins and a major orogeny at the Devonian-Carboniferous boundary; and (3) central and western Morocco, which corresponds to the external zones of the European Hercynides.The Marrakech-Kabylia zone separates the Variscan domain from the stable and undeformed West African craton. During Early Palaeozoic times it began as an extensive or transtensive zone. It has been deformed by the Late Devonian orogeny and by Carboniferous and Permian reactivation. The zone represents the southern limit of the Hercynian chain and is distinguished by its transcurrent regime throughout the Late Palaeozoic.
Correspondence to: A. Piqué 相似文献
37.
本矿物为新发现的钇易解石族的端员矿物-钛钇易解石,产于江西省龙南县足洞燕山期中粒白云母花岗岩及其风化壳中。矿物属斜方晶系,常呈板状或短柱状,为天然晶质体,浅黄色,粒度为0.075mm,硬度4.7,比重4.73,二轴正晶,Ng=2.248,Nm=2.212,Np=2.194,Ng-Np=0.054,2V=70°。空间群为D^162h-Pmnb,a0=0.750nm,b0=1.092nm,C0=0.5 相似文献
38.
T. Ch. Malleswara Rao K. Narasimha Rao K. V. K. Mohana Rao 《Journal of the Indian Society of Remote Sensing》1986,14(1):67-76
This paper discusses the geometric anomalies present in bulk images which are being generated on NRSA Data Processing System (DPS). A georeference correction algorithm has been presented to correct geometric scale anomalies in a systematic manner. An approach to generalize and integrate georeference correction algorithm with existing bulk correction program has been realised without crippling the speed of DPS film product generation Software. Limitations and accuracy of the algorithm are discussed. 相似文献
39.
Operational stochastic models with different time discretisation levels have been developed for generation of meteorological input processes for hydrologic models. These stochastic models can also supply the input simulation for water quality management models. In this paper they are outlined with special regard to the threshold model for intermittend processes of short time intervals (less than about ten days) with is based on a “pressed” power transformation to normality and a method of quantiles or alternatively a modified method of moments for estimating the correlation coefficients. 相似文献
40.
Planetary waves in coupling the lower and upper atmosphere 总被引:1,自引:1,他引:1
A.I. Pogoreltsev A.A. Vlasov K. Frhlich Ch. Jacobi 《Journal of Atmospheric and Solar》2007,69(17-18):2083
The purpose of the paper is to answer the question if planetary waves (PW) are capable of propagating into the thermosphere. First the simplest vertical structure equation of the classic tidal theory accounting for a realistic vertical temperature profile is considered. Analysis and simulation show that the well-known normal atmospheric modes (NM), which are trapped in the lower and middle atmosphere, exhibit a wave-like vertical structure with a large vertical wavelength in the thermosphere. Moreover, the reflection of these modes from the vertical temperature gradient in the lower thermosphere causes appearance of the wave-energy upward flux in the middle atmosphere, and in a linearized formulation this flux is constant above the source region. To investigate a possibility of the NM forcing by stratospheric vacillations and to consider the propagation of different PW up to the heights of the upper thermosphere, a set of runs with a mechanistic Middle and Upper Atmosphere Model has been performed. The results of the simulation show that quasi-stationary and longer-period PW are not able to penetrate into the thermosphere. The shorter-period NM and ultra-fast Kelvin wave propagate up to the heights of the lower thermosphere. However, above about 150 km they are strongly suppressed by dissipative processes. The role of the secondary waves (nonmigrating tides) arising from nonlinear interaction between the primary migrating tides and quasi-stationary PW is discussed. We conclude that PW are not capable of propagating directly up to the heights of the ionospheric F2 region. It is suggested that other physical processes (for instance, the electrostatic field perturbations) have to be taken into account to explain the observed PW-like structures in ionospheric parameters. 相似文献