A pre-Paleogene unconformity surface of the Sikeshu Sag, Junggar Basin: Lithological, geophysical and geochemical implications for the transportation of hydrocarbons

The unconformity surface at the bottom of the Paleogene is one of the most important migration pathways in the Sikeshu Sag of the Junggar Basin,which consists of three layers：upper coarse clastic rock,lower weathering crust and leached zone.The upper coarse clastic rock is characterized by higher density and lower SDT and gamma-ray logging parameters,while the lower weathering crust displays opposite features.The transport coefficient of the unconformity surface is controlled by its position in respect to the basal sandstone; it is higher in the ramp region but lower in the adjacent uplifted and sag areas.The content of saturated hydrocarbons increases with the decrease of the content of nonhydrocarbons and asphaltenes.The content of benzo[c] carbazole decreases as the content of benzo[a]carbazole and [alkyl carbazole]/[alkyl ＋ benzo carbazole] increases.This suggests that the unconformity surface is an efficient medium for the transportation of hydrocarbons.

Pure aromatic hydrocarbons with meta-linked phenyl-core and perihedral fluorene substitutions with/without inert groups of tert-butyl： bipolar hosts for blue phosphorescence

Two pure hydrocarbon molecules of l,3,5-tris(9-phenyl-9H-fluoren-9-yl)benzene(mTPFB)and l,3,5-tris(2-tert-butyl-9-phenyl-9H-fluoren-9-yl)benzene(tBu-mTPFB)were synthesized.Due to the conjugation blocked connection mode and rigid/bulky substitutions,these two materials possess high triplet energy,enabling them as good hosts for blue phosphor in PhOLEDs.By studying their thermal,electrochemical,electronic absorption and photoluminescent properties,it was found that the influence of the inert tert-butyl group on material photoelectrical properties is negligible.For instance,mTPFB and tBu-mTPFB showed very similar absorption and emission profiles,with almost the same bandgap,triplet energy and energy levels.However,the encapsulation of tert-butyl on the 2-position of 9-phenylfluorene enhanced material thermal stability.Most importantly,carrier transport properties were improved dramatically,as proved by the mono carrier device.Blue phosphorescent OLEDs hosted by tBu-mTPFB showed external quantum efficiency of 15.2%and current efficiency of 23.0 cd/A,which were much higher than that of the OLEDs based on mTPFB with the analogous structure.