In this study, a full-potential density functional theory was used to investigate the effects of Ti substitution by different cations. In both rutile and anatase, Ti atom was replaced by Ce, Au, Sn, Ag, Mo, Nb, Zr, and Y. Phase stability, electronic structure and formation energy of oxygen vacancy were compared for rutile and anatase. The results indicated that substitution of Ce and Zr increas...

the source of cement in oilfields is critical to the prediction of the distribution of cements in the reservoirs and also prediction of reservoir quality. the source of mineral forming cements has been determined for the storrington oolitic carbonate reservoir (middle jurassic great oolite formation, weald basin, onshore uk) using a combination of petrography, electron microscopy, fluid inclusi...

in order to study the stratigraphic of sedimentary deposits of the cenomanian in kopeh dagh, the taghiabad section was selected. in the eastern kopeh dagh, the upper part of aitamir formation has this time range characteristic. the upper part of this formation includes shale and glauconitic sandstones and contains variety of ammonite fauna. ten genera and species of ammonites are found inside t...

In an attempt to reconstruct the paleoenvironments of deposition for the Middle Jurassic Baghamshah formation, samples collected from six outcrop sections along the Shotori swell were subjected to detailed geochemical analyses. Bulk geochemical and biological marker data indicate a logical trend of the variation of organic input, salinity, and oxicity within Baghamshah paleoenvironments across ...

Hamadan province in western Iran has always been of particular archaeological significance mainly because its administrative centre Ecbatana, modern Hamadan. In 2005 a bas-relief dating to the Parthian period was found southern highlands Alvand, Yakhchal valley. Recently, second relief, very similar one, at Mydan Mishan. This relief depicts person lying on klinè with his legs stretched out and ...

During the Middle-to-Late Miocene, diatomaceous sediments were deposited in North Pacific margin and marginal basins. The Onnagawa Formation is one of such deposits, which shows cyclic sedimentary rhythms reflecting oscillations marine environment Japan Sea. However, age still poorly constrained due to poor preservation siliceous microfossils. To better constrain its age, we performed U-Pb dati...