Excitation of PtI transitions ending at the levels of the main term

We have experimentally studied the excitation of transitions of the platinum atom ending in levels of the ³D main term. The atoms were excited by a 30 eV monoenergetic electron beam. The lines studied are located at wavelengths of 204–367 nm. The largest of the measured excitational cross sections exceed 10^?16 cm². The optical-excitation functions measured at electron energies of 0–200 eV have complex structures.     

Resonance Magnetic Conversion of Photons Into Massless Axions and Striking Feature in Quasar Polarized Light

The effect of massless Nambu-Goldstone bosons (massless axions) on the appearance of striking feature in QSO polarized light is suggested. This feature can be appeared in a result of resonance magnetic conversion of photons into massless axions. The resonance magnetic conversion can take place for mixture of electron plasma and neutral hydrogen gas into a magnetic field in the regions of Damped Ly- systems. The QSOs with a noticeable Faraday rotation measures should be suitable targets for polarimetric observations.     

Applying an optimized proxy-based workflow for fast history matching

History matching is still one of the main challenging parts of reservoir study especially in giant brown oil fields with lots of wells. In these cases, history matching with conventional manual technique needs many runs and takes months to get a match. In this work, an innovative approach was suggested for fast history matching in a real brown field. The workflow was employed based on an optimized proxy model for history matching of a field consisting of 14 active wells with multiple responses (which are production rate and pressure data) in the south part of Iran. The main important features of the proposed algorithm were defining a proxy model which is response surface method in which 21 model parameters were incorporated based on cubic centered face method. The proxy model was then optimized by one of the most famous algorithms which is genetic algorithm. Proxy model was successfully performed using 256 samples leading into p- value of 0.531 and R ² of 0.91 dataset. As a result, the proposed workflow and algorithm showed good and acceptable results for history matching of studied real model.     

Deterioration of Sediment Quality in Seagrass Meadows (<Emphasis Type="Italic">Posidonia oceanica</Emphasis>) Invaded by Macroalgae (<Emphasis Type="Italic">Caulerpa</Emphasis> sp.)

Species of the macroalgae Caulerpa sp. are increasingly being observed in meadows of the endemic Mediterranean seagrass Posidonia oceanica, and in particular Caulerpa taxifolia, has been considered as an invasive species leading to seagrass decline. Studies have so far failed to reveal the underlying mechanisms of the success of the macroalgae, and here, we examine how biogeochemical changes of the environment associated to indigenous (Caulerpa prolifera) and non-indigenous (Caulerpa racemosa and C. taxifolia) species affect the habitat of P. oceanica. Two of the species (C. prolifera and C. racemosa) affect the sediment biogeochemical conditions by increasing organic matter pools, microbial activity, and sulfide pools of the sediments, and limited effects were found for C. taxifolia. Biomass of the macroalgae contributed to the extent of impacts, and high sulfide invasion into the seagrasses and regression of the meadow were pronounced at the location with the highest Caulerpa biomass. This suggests that Caulerpa invasion contributes to seagrass decline probably because Caulerpa thrives better than the seagrasses in the modified environment.     

Lang Trang Cave (Northern Vietnam): Pleistocene Mammalian Locality with Gigantopithecus Finds

Doklady Earth Sciences - Speleological, geological and paleontological characteristics of the Lang Trang cave in northern Vietnam are presented. Primates Gigantopithecus blacki von Koenigswald,...     

Die stratiforme Sulfidlagerstätte Walchen,Steiermark, Österreich: Geochemie und Genese

Zusammenfassung Die Neubearbeitung derstratiformen Sulfidlagerstätte Walchen bei Öblarn, Steiermark, offen-bart eine eisenbetonte submarin-exhalative Metallkonzentration in einem vulkano-sedimentären Rahmen. Dieser liegt heute in Form metamorpher Gesteine der untersten Grünschieferfazies vor. Mineralchemische Untersuchungen zeigen, daß die ehemalige intensivste metamorphe Überprägung der Lagerstätte im Bereich von 450°–500°C oberhalb 4 kb stattgefunden hat. Metavulkanite, vertreten durch Grünschiefer, lassen alkalibasaltische Affinität erkennen. Die vulkano-tektonische Position der Lagerstätte ist in einem intrakontinentalen Riftsystem zu sehen.

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The stratiform sulphide deposit at walchen, styria, austria: Geochemistry and genesis

Summary The Walchen deposit consists of a 1–2 m thick layer of massive to disseminated pyrite-pyrrhotite-chalcopyrite ore with an average grade of 1% Cu. It has been mined intermittently in the past. The ore horizon occurs within sericitic and quartzitic phyllites which carry intercalations with significant carbonate, garnet and graphite contents. The succession is of lower Paleozoic age and forms part of the Grauwackenzone, a volcano-sedimentary unit which separates the Central Alps from the Northern Calcareous Alps.The precursor rocks of the ore environment have been pelites and sandstones; greenschists occur in the hanging wall of the mineralization. Major and trace element analyses of greenschists reveal them as low-grade metamorphic equivalents of continental alkali basalts. Hydrothermal systems generated by volcanic activity were responsible for deposition of stratiform sulphides. The predominance of clastic sediments and the absence of stringer zones point towards a shallow depositional basin.Microprobe analyses of garnets from the ore environment reveal an increase in spessartine contents from 7 mol% in phyllites to 20 mol% in the vicinity of the ore horizon. Similar data have been reported from other stratabound base metal deposits (Broken Hill, N.S.W.; Kreuzeck Mountains, Austria; Gamsberg, South Africa); the manganese concentrations represent fossil manganese haloes.Pyrite carries minor Ni and Co (up to 0.03, respectively 0.3%), pyrrhotite averages 0.8% Ni and 0.1% Co, Fe-contents of sphalerite vary from 6.41–9.33%; Cd, In and Mn have not been recorded.Garnet-biotite pairs suggest maximum metamorphic temperatures of 450°–500°C: pressures of 4 to 5 kb have been estimated. The Walchen deposit is interpreted as the product of submarine exhalative processes in an incipient rift. It was affected by prograde metamorphism during the Variscan orogeny, and by retrograde affects during a later event. Isochemical metamorphism resulted in the preservation of a primary manganese halo.

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Reconstruction of the harmonic component of the magnetic field modulus anomalies

An algorithm is proposed for calculating a harmonic function equal to the projection of the anomalous magnetic field vector onto the normal field direction from in situ measurements of the anomalous magnetic field modulus (the scalar magnetic anomaly) ΔT, which is a nonharmonic function and is nonlinearly related to the magnetization of anomaly sources. It is shown that the inferred estimates tend to the desired harmonic function if the iterative algorithm converges. The convergence conditions and stability of the process are studied numerically in a wide range of amplitudes of the anomalous field. The results of the modeling simulation demonstrate the efficiency of the proposed algorithm in solving magnetic field interpretation problems often encountered in practice.