Carte Métallogénique de la Bulgarie

Résumé On peut, en résumé, caractériser ainsi les principales provinces de la Bulgarie: — les Rhodopes constituent une zone typiquement polymétallique avec une prépondérance soulignée de Pb, Zn; le F, Cr, Ni, y existent en quantité subordonnée; en traces viennent encore: le Ba, Mn, Cd, Sb, W, Mo, Bi, As, Au, Ag, V; — la Sredna Gora est caractérisée comme une zone de cuivre typique, avec la présence de Fe, Mn, et en quantitée subordonnée de Pb, Zn, Mo, Ti, V, Au. — les Balkans portent les particularités d'une zone polymétallique (Pb, Zn, Cu) avec fer. On y remarque souvent des gîtes individualisés de cuivre, polymétallique avec fer, argent, ainsi que des gîtes complexes. Le Mn, Ba, Au, Ag, Co, Mo, As, Hg, V, W viennent en quantité subordonnée; — la zone des Kraistides, analogue à la précédente, se caractérise par des gisements polymétalliques pauvres et des gîtes à or et scheelite. Les éléments principaux sont: Au, Ba et secondaires: Pb, Zn, Cu, V et en partie du Fe et Hg; — la plateforme mésique, outre le gaz, se caractérise par le manganèse de la dépression de Varna.

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The metallogenic map of Bulgaria displays the following four major and distinct provinces: The Rhodopes as a typically polymetallic zone, mainly with Pb and Zn, but also with F, Cr and Ni, and minor or trace amounts of Ba, Mn, Cd, Sb, Mo, Bi, As, Au, Ag, V. The Sredna-gora is a distinct copper zone, with Fe and Mn, and minor amounts of Pb, Zn, Mo, Ti, V, Au. The Balkan is again a polymetallic zone of Pb, Zn and Cu with Fe; but Cu-Fe-Ag-deposits also occur. The other elements are present in minor quantities only. The Kraiste-Zone resembles the previous one and contains low grade polymetallic and scheelite deposits. The main elements are Au, Ba, and minor quantities of Pb, Zn, Cu, V and in part Fe and Hg. The zone of the Mésie platform contains only the manganese deposits of the Varna depression, in addition to natural gas.

     

Carbon dioxide partial pressures in North Pacific surface waters — Time variations

Observations were made of time variations of the carbon dioxide partial pressures (Pco₂) of the atmosphere and surface sea waters in the Pacific subarctic region. Data were obtained on a cruise of the USC & GSSSURVEYOR in October, 1968 and on the TRANSPAC expedition of the CNAVENDEAVOUR in March–April, 1969. A rise in surface water Pco₂ of 18×10^–6 atm occurred in a period of 30–45 days in March–April due principally to spring warming of surface waters. An average increase of 60×10^–6 atm occurred between October, 1968 and March, 1969 as a result mainly of cessation of summer phytoplankton production and the onset of winter-storm-driven vertical mixing. Because the air-sea Pco₂ gradient not only changed appreciably in magnitude but also changed sign, there are important implications for calculations of air-sea exchange of carbon dioxide on the ocean wide scale.Data contained in this paper comprise part of a dissertation to be submitted by Louis I. Gordon in partial fulfillment of the requirements for the Ph. D. at Oregon State University.     

Assessment of imposex in the common whelk, Buccinum undatum (L.) from the Eastern Scheldt, The Netherlands

Several cruises were carried out on the Eastern Scheldt between September 1992 and March 1995 to study the frequency and appearance of imposex in the common whelk, Buccinum undatum L. Incidences of imposex were always > 90%. For the first time several stages of imposex in Buccinum undatum are reported. The evolution of imposex in the whelk seems to follow a similar route as in Hinia reticulata belonging to the same superfamily (Buccinacea). Tissue organotin concentrations of animals collected in February 1995 showed the highest organotin concentrations in the digestive gland and lowest in the foot of the animals. Concentrations of phenyltin compounds (up to 625 ngSn/g DW) were much higher than those of butyltin compounds (up to 40 ngSn/g DW).     

Numerical modelling of the seasonal variability of hydrophysical fields in the Black Sea

The results of research into the seasonal variability of hydrothermodynamic characteristics of the Black Sea are presented. These have been obtained using field data on the fields of temperature, salinity, and wind, and by mathematical modelling. The seasonal variability of the current and heat content fields and of the cold intermediate layer and other hydrophysical characteristics is discussed.Translated by Mikhail M. Trufanov.     

盐胁迫对番茄同工酶基因表达的影响

分析了普通番茄（Lycopersicumesculentum）在NaCl胁迫下酯酶（EST）和过氧化物酶（PRX）同工酶的变化，考察了盐胁迫对10个同工酶位点21个等位基因在特定组织中表达的影响。发现许多EST和PRX等位基因在盐胁迫下表达，产生盐诱导同工酶；另有些等位基因的表达受盐抑制，它们在盐胁迫下的表达活性显著减弱或消失。实验表明，EST和PRX同工酶表达的变化与番茄对盐胁迫的遗传适应性有密切关系。     

Magnitude-frequency relationship of coastal sand delivery by a southern California stream

Coastal sand delivery by a stream in southern California is estimated based on a numerical model which stimulates unsteady flow, sediment transport, and the associated channel adjustments for a stream-delta system. An average annual sediment yield of 51,400 m³/yr is estimated for the San Dieguito River, which drains a semiarid watershed controlled by dams. Of the total sand delivery by the stream, 20.5 percent is contributed from floods greater than the 100-year flood; 17.6 percent from those between the 50- and 100-year events; 28.4 percent from those between the 25- and 50 year floods; and 33.5 percent from those smaller than the 25-year flood.     

Field observations of waves generated by passing ships: A note

This short contribution reports the results of a field study on the nearshore characteristics of waves generated by both conventional and high speed passenger ferries. The field observations took place in the late summer of 2005, at a beach close to the port of Mytilene (Island of Lesbos, Greece), and involved the visual observation of ship waves, using digital video recordings and image processing techniques. The results showed that passage of the fast ferry was associated with a longer, more complex and energetic nearshore event; this event not only did include higher nearshore waves (up to 0.74 m) and was organised in different wave packets, but it was also an order of magnitude longer (∼ 680 s) than the conventional ferry event. Regarding the effects on beach sediment dynamics, the fast ferry waves were estimated to be very efficient in mobilising the nearshore sediments in contrast to those of the conventional ferry. The fast ferry service appears to generate daily prolonged nearshore events, which contain waves with higher energy than those expected from the normal summer wind wave regime of the area; these events also include some high and very steep waves, which can be particularly erosive. Therefore, fast ferry wakes may have considerable impacts on the seasonal beach sediment dynamics/morphodynamics and the nearshore benthic ecology, as well as they may pose significant risks to bathers, affecting the recreational use of the beaches exposed to fast ferry traffic. Finally, the study has shown that satisfactory field observations of the nearshore characteristics of ship-generated (and wind) waves can be obtained using inshore deployments of calibrated poles, digital video cameras and appropriate image processing algorithms.     

Photochemical models of the atmosphere and their application in ozonosphere and climate studies: A review

This review is devoted to problems in the photochemical modeling of atmospheric processes. The physicochemical and mathematical foundations underlying the construction of photochemical models are described, a classification of the atmospheric reactions is presented, and the features of photochemical modeling are considered under various irradiance conditions for various atmospheric layers and geographical regions. Atmospheric processes that are important to photochemical models are discussed. Applications involving photochemical models are outlined. Some results are presented to illustrate the capabilities of photochemical models. Special attention is given to relatively recent directions in photochemical modeling, such as data assimilation and inverse problems. The review can be used by experts in areas related to atmospheric chemistry as a basic source of knowledge on the subject and for the development of photochemical modules for atmospheric models.