نتایج جستجو برای: kerogen
تعداد نتایج: 462 فیلتر نتایج به سال:
The Early Cambrian (approximately 540 million years old) Meishucun fossil assemblage of Ningqiang County (Shaanxi Province), China, contains the oldest complex skeletonized organisms known in the geological record. We here report the finding in this assemblage of an exquisitely preserved late-stage embryo of a ctenophore ("comb jelly"), its fine structure documented by confocal laser scanning m...
Ultrasonic extraction of kerogen derived by acid treatment of Huadian oil shale is performed using an organic solvent. The most effective solvent is the 60:40 (wt%) mixture of chloroform and carbon disulfide, and the suitable mass ratio of the demineralized oil shale to solvent is 1:20. The oil yield by ultrasonic extraction can reach 15.6% based on the demineralized oil shale, compared with a ...
Naturwissenschaften 78 (1991) © Springer-Verlag 1991 been considered as major precursors of humin [l 3]. The classical concepts of the nature of the humin have been questioned over the last few years. Recent studies using l3C NMR spectrometry point to the need of identifying the nature of paraffinic material in the fine soil fractions [4]. The origin of the polymethylene structures in soil humu...
Hydrocarbon recovery from unconventional reservoirs (shale gas) is debated due to its environmental impact and uncertainties on its predictability. But a lack of scientific knowledge impedes the proposal of reliable alternatives. The requirement of hydrofracking, fast recovery decay and ultra-low permeability-inherent to their nanoporosity-are specificities of these reservoirs, which challenge ...
Ambient pyrites of two distinct types were described from middle Precambrian rocks of the Lake Superior area. A new class of this phenomenon is here described from middle Precambrian chert from western Australia. The newly found ambient pyrites are quite minute and characteristically occur in groups forming a "starburst" pattern. All three types of ambient pyrite may be explained in terms of pr...
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