Wyniki wyszukiwania - BazTech

Ograniczanie wyników

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Tectonic origin of the unique Holocene travertine from the Holy Cross Mts. : microbially and abiologically mediated calcium carbonate, and manganese oxide precipitation

Gruszczyński M., Kowalski B. J., Sołtysik R., Hercman H.

Acta Geologica Polonica

2004

Vol. 54, no. 1

61--76

Recent tectonic activity of the main dislocation within the Paleozoic core of the Holy Cross Mts. led to formation of a large travertine dome of Holocene age. The main body of the travertine is built up of extremely fast crystallized calcite from highly supersaturated solutions derived from hydrothermal waters circulating through the tectonic dislocation. Many calcite crystals display the remains of calcified bacilliform bacteria rods suggesting an essential part, of the calcite crystallization process was on a bacterial precursor. Successively, after the micrite calcite travertine frame had been formed, almost pure monoclinic manganese oxide (A-MnO2) precipitated filling part of the remaining porosity. The unique characteristics of manganese oxide crystallization also suggest a very fast process of manganese oxidation due to increase in Eh and the activity of abundant fungal species which might be associated with a specific symbiotic bacterium. Specfic arrangement of the A-MnO2 crystals into the rosettes seems to be achieved by fast evaporation of upwards migrating solutions from the tectonic zone. The last in this succession is calcite cement filling the pores, mainly in the upper part of the travertine frame. Generally, this was abiologically mediated process of precipitation of calcium carbonate due to rapid degassing of carbon dioxide and occasionally, in the top of the travertine dome, due to direct precipitation from the ground waters.

Azotek galu : nowy rozdział w badaniach powierzchniowej struktury elektronowej półprzewodników

Kowalski B. J., Iwanowski R. J., Kopalko K., Orłowski B. A., Sadowski J., Kanski J., Pluciński Ł., Johnson R. L., Grzegory I., Porowski S.

Elektronika : konstrukcje, technologie, zastosowania

2001

Vol. 42, nr 8-9

23-25

The results of investigations of the (0001) (N-polar) surface of GaN bulk crystals are presented together with a brief review of the knowledge about GaN surface electronic structure accumulated up to the present. The band structure of GaN(0001) - (1 x 1) in the directions G-A and G-K has been analysed on the grounds of the data obtained by means of angle-resolved photoemission spectroscopy. The proposed interpretation of the results is shown to be consistent with the available results of calculations based on the model of the GaN(0001) - (1 x 1):Ga surface.

From metal-semiconductor junction to ternary alloy crystal

Guziewicz E., Orłowski B. A., Kowalski B. J., Barrett N., Belkhou R., Radosavkic D., Martinotti D., Guillot C., Lacharme J. P., Sebenne C. A.

Electron Technology

1998

Vol. 31, No. 3/4

323-327

Paper presents the application of the photoemission electron spectroscopy (PES) for investigation of the valance band electronic structure of clean CdTe (110) surface relaxed 1 x 1 and this surface sequentially covered by small amount (from 0.2 to 20 ML) of Fe atoms. In the first stages of the Fe depositon (0.2 ML up to 0.6 ML) the creation of the ternary alloy Cd1-xFexTe mainly occurs. For further Fe deposition the Fe layers if formed over the Cd1-xFexTe surface. Diffusion of the Fe atoms occurs under the sample heating, and it leads to the creation of the Fe enriched Cd1-xFexTe ternary alloy.