نتایج جستجو برای: carbon and sulfur stable isotopes
تعداد نتایج: 16921217 فیلتر نتایج به سال:
for this study, asmari (oligo-miocene) and bangestan (cretaceous) reservoir oils from themarun oilfield were studied geochemically. gas chromatograms and stable isotopes of carbon and sulfur indifferent oil fractions were studied. normal alkanes nc15+ are as high as 93% with a saturate percentage up to53.9% which reveal a high maturity of asmari and bangestan reservoir paraffinic oils. carbon p...
1. Background 2. Elements, Nuclides, and Stable Isotopes 3. The Mass Spectrometer and Isotope Ratio Measurement 4. Isotope Fractionation 5. Temperature and Fractionation 6. Stable Isotopes in the Hydrologic Cycle 7. O in Minerals and Rocks 8. C and Carbon Cycling 9. N Cycling in Watersheds 10.S and the Sulfur Cycle 11. Chlorine and Bromine Isotopes 12. Light Lithophile Elements: δLi and δB Glos...
the upper cretaceous carbonate sequence of ab-deraz formation is well exposed in the kopet- dagh basin. this formation comprises marly limestone and three chalky limestone units. chalky limestone of ab-deraz formation is mainly composed of calcareous dinoflagellate (pithonellid calcispher), cocolithofore and planktonic foraminifera. carbon and oxygen stable isotopes analysis of the third chalky...
The mass spectrometric analysis of the impact of sulfur dioxide and dust emission on carbon and oxygen stable isotopic compositions of glucose hydrolysed from α-cellulose samples extracted from Scots pine growing in the vicinity of "Huta Katowice" steelworks was the main aim of this study. The annual rings covered the time span from 1975 to 2012 AD. The relationships between climatic conditions...
The application of stable isotope analysis (SIA) has become a standard scientific approach in Agricultural and Ecological researches and, more in general, in several disciplines such as biology, botany, zoology, organic chemistry, climatology, and nutrition. The main objectives of this paper are (1) to provide a simple definition of stable isotopes and (2) to illustrate analytical measurement m...
The effect of organic enrichment of sediments on the composition of stable sulfur isotopes (δ34S), sulfide invasion (Fsulfide) and concentrations of total sulfur (TS) and elemental sulfur (S0) in the seagrass Posidonia oceanica was investigated along transects from 3 Mediterranean fish farms in Spain, Italy and Greece. The δ34S decreased and Fsulfide, TS and S0 decreased with distance from the ...
In order to understand spatial variations of stable isotope geochemistry in the Quruqtagh basin (northwestern China) in the aftermath of an Ediacaran glaciation, we analyzed carbonate carbon isotopes (dCcarb), carbonate oxygen isotopes (dOcarb), carbonate associated sulfate sulfur (d SCAS) and oxygen isotopes (d OCAS), and pyrite sulfur isotopes (d Spy) of a cap dolostone atop the Ediacaran Han...
Sulfur stable isotopes are increasingly being used as tracers of material processing in studies of both modern and historical food webs. Preparation of plant and animal material for isotope analysis routinely includes steps that remove inorganic material not normally assimilated by consumers. Whereas acidification of samples is known to assist with this for some elements (carbon), it can produc...
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