Thermal maturity is an important geochemical parameter for the study of source rocks in unconventional shale plays. Using well logs to estimate thermal maturity would overcome the discontinuity of core sample analysis and can provide continuous profiles. However, estimating thermal maturity from well logs, unlike total organic carbon (TOC) content has received less attention. In this paper, we used vitrinite reflectance (Ro) to characterize thermal maturity and proposed a practical method to produce a continuous profile of thermal maturity from well logs. For this purpose, a maturity indicator (Im) regarding with kerogen element compositions and types was defined. Im was calculated for different kerogen types based on their H/C versus O/C atomic ratios. It was found that Ro decreases with the Im of all three types of kerogen monotonically, which was used as a foundation for thermal maturity predictions. Then, the Im was related to the compensated neutron log (CNL) responses of kerogen by considering the variations in elemental compositions of organic matter with maturity. Based on known CNL response of major sedimentary minerals and pore fluids, a petrophysical equation was established to obtain Im from well logs. Finally, the proposed method was applied to Chang 7 Shale of Triassic Yanchang Formation of the Ordos Basin, China and the Bakken Shale of Williston Basin, North Dakota, USA, two major source rocks with different kerogen types and maturities. The results showed an acceptable agreement between lab measurements and predictions of Ro with a good correlation coefficient, verifying the new method is effective and reliable.
This paper examines two inscriptions used by Christian Marek (2003, pp. 66-67; 2015, pp. 308-309) to support his thesis that the coastal Paphlagonian koinon – known in epigraphical sources as “the Koinon of the Cities in Pontus” – was already established in the Julio-Claudian period, if not earlier.The first inscription from Pompeiopolis is reported by Fourcade (1811) that can date to the early Augustan period or earlier. Marek himself focused on the Pompeiopolis inscription in his rejoinder to Loriot’s thesis in a recent article (2015), arguing that Loriot is wrong to date this inscription to the imperial period. Alternatively, this paper proposes that a separate inscription invoked by Marek in his earlier work may be more effective.The second inscription dates to the reign of Claudius. It comes from a rupestral column-and-niche roadside monument in the outskirts of ancient Amastris. The monument concerns two cults, Theos Hypsistos and Divus Augustus. Theos Hypsistos received a dedication consisting of a column and a perched eagle, and the column base inscribed with a short dedicatory inscription. There are two other tabulae ansatae, possibly associated with the niched figure, recording the same title ὁ τοῦ ἐπουρανίου θεοῦ Σεβαστοῦ ἀρχιερεὺς, and the Latin equivalent of this priesthood was perpetuus sacerdos Divi Augusti. That ἐπουρανίου does not have a correlate term in the Latin title, along with the presence of a dedication to Theos Hypsistosimmediately next to the niche monument, suggests that this priesthood was in charge of a syncretistic imperial cult, and was different from the highpriesthood of the municipal imperial cult attested in a separate Amastrian inscription dated to the Neronian period.This paper argues that the syncretistic imperial cult dedicated to Divus Augustus and Theos Hypsistos may have been established as an extra-urban cult designed for an audience broader than the inhabitants of Amastris proper. The so-called Oath of Gangra makes it clear that part of the binding force of such an oath of loyalty was the invocation of local deities to enforce retribution. We are also informed by the same oath that such oaths of loyalty had to be administered in both the city proper and the chora “at the altars of Augustus in the sanctuaries of Augustus” as part of an annual and province-wide exercise. The two information points to the possibility that the the syncretistic cult from the extra-urban monument near Amastris may have been part of a complex that could be described as a sanctuary of Augustus, with a targe audience not from Amastris proper, but from the Amastris chora. The fact that the extra-urban monument was carved into the rockface beside a Roman road that was cut but Gaius Iulius Aquila, an equestrian and permanent holder of the highpriesthood overseeing this syncretistic cult, has further implications. Tacitus reported a campaign in 49 CE in the Bosporus, in which one Iulius Aquila successfully led a coalition force against the uprising of Mithridates (Tac. Ann. 12.15-21). If this military commander was indeed Gaius Iulius Aquila the highpriest, the extra-urban monument may have further political significance that resembles the Ara Romae et Augusti ad confluentes Araris et Rhodani, which was built and maintained by a priesthood created by a local elite following the successful suppression of the Sugambri and their allies by Drusus (Dio Cass. 54.32.1), and served as the gathering place for the concilium of the Tres Galliae. Fishwick argues that Drusus created a federal concilium by inviting the leading men of the Gallic provinces to participate in its management and organization, so that leading men could have the opportunity to discuss mutual concerns and put for complaints against Roman authorities (Fishwick 2002, pp. 12-13).
We studied temperature-dependent amplified spontaneous emission (ASE) in CsPbBr3 perovskite thin films. For temperatures 180-360 K, a narrow-band lasing is observed. However, a new accompanying ASE band appears below 180 K, indicating a more complicated behavior. The two ASE bands are strongly correlated and in competition; they are assigned as exciton and bi-exciton recombination. We estimated the exciton binding energy (E-B = 27.3 meV) and that of the bi-exciton, which is lower than the E-B. The reduced effective mass of the exciton is estimated as mu = 0.11 m(c). This discovery identifies more details of the ASE phenomenon. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Since its initial proposal, steam-assisted gravity drainage (SAGD) has become a key technology of heavy-oil recovery. Due to the large heat loss and high energy consumption in the SAGD process, gas-assisted SAGD is a way to improve the efficiency. In this paper, a two-dimensional (2D) visualization simulation experiment of SAGD is introduced. By adjusting the volume ratio of steam to nitrogen, the proportion for the nitrogen-assisted SAGD process is optimized based on a homogeneous model. The 2D visualization simulation experiment of a heterogeneous model is carried out by adjusting the length of a low-permeability interlayer. The results of the SAGD simulation experiment and nitrogen-assisted SAGD simulation experiment are analyzed. The effect of nitrogen on breaking through and bypassing the low-permeability interlayer is discussed. The experimental results show that the optimal volume ratio of steam to nitrogen is 8:2 in the process of nitrogen-assisted SAGD. At this volume ratio, the sweep efficiency, recovery factor and cumulative oil-steam ratio are the largest, and the recovery factor reaches up to 49.12%. The experimental results for the heterogeneous model with the low-permeability interlayer show that nitrogen can synergistically promote steam to break through the fully occluding interlayer and bypass partially occluding interlayers. Comparing the results of the SAGD simulation with those of the nitrogen-assisted SAGD simulation for the heterogeneous model with the low-permeability interlayer, it is found that the sweep efficiency of steam increases from 34.24% to 43.12%. This result can be explained by the effect of nitrogen on expanding the steam-swept area in the SAGD process and the synergistic action between nitrogen and steam.
The environmental risks and health impacts associated with particulate organophosphate flame retardants (OPFRs), which are ubiquitous in the global atmosphere, have not been adequately assessed due to the lack of data on the reaction kinetics, products, and toxicity associated with their atmospheric transformations. Here, the importance of such transformations for OPFRs are explored by investigating the reaction kinetics, degradation chemical mechanisms, and toxicological evolution of two OPFRs (2-ethylhexyl diphenyl phosphate (EHDP) and diphenyl phosphate (DPhP)) coated on (NH4)(2)SO4 particles upon heterogeneous OH oxidation. The derived reaction rate constants for the heterogeneous loss of EHDP and DPhP are (1.12 +/- 0.22) x 10(-12) and (2.33 +/- 0.14) x 10(-12) cm(3) molecules(-1) s(-1), respectively. Using recently developed real-time particle chemical composition measurements, particulate products from heterogeneous photooxidation and the associated degradation mechanisms for particulate OPFRs are reported for the first time. Subsequent cytotoxicity analysis of the unreacted and oxidized OPFR particles indicated that the overall particle cytotoxicity was reduced by up to 94% with heterogeneous photooxidation, likely due to a significantly lower cytotoxicity associated with the oxidized OPFR products relative to the parent OPFRs. The present work not only provides guidance for future field sampling for the detection of transformation products of OPFRs, but also strongly supports the ongoing risk assessment of these emerging chemicals and most critically, their products.