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Abstract The paleoenvironment of Jixian carbonate rocks in the Mesoproterozoic Ordos Basin is studied by carbon and oxygen isotope analyses, diagenetic environment analysis, and the restoration of paleosalinity and paleotemperature. The results indicate that the carbonate rocks of the Jixian System have always been in a near-surface environment and have not been deeply buried. The ranges of variation in δ13CPDB and δ18OPDB are relatively narrow, ranging from − 5.75 to 1.41‰ and − 8.88 to − 4.01‰, respectively, which is consistent with the stable tidal flat sedimentary environment during the Mesoproterozoic in the study area. The paleosalinity (Z) values range from 111.7 to 127.1, and the paleotemperature (T) values range from 32.7 to 57.33 °C, indicating a relatively warm paleoclimatic environment during the Mesoproterozoic era in the study area. The analysis shows that in a warm paleoclimatic environment, although carbon and oxygen isotopes, Z, and T have certain fluctuations, their ranges are relatively small, reflecting to some extent the stable tectonic environment of the study area during the Mesoproterozoic era. Comprehensive research shows that the Ordos Basin had a warm climate and a stable tectonic environment in the Mesoproterozoic, which may be a good response to the North China Block's position near the equator and continuous thermal subsidence in the Mesoproterozoic.

Increasing exploration interest in oil and gas hosted by early Cambrian strata has focused research efforts on early Cambrian sandstones. The origin of phosphorus and the paleoenvironment of phosphorus-bearing sandstones from the Xinji Formation are discussed in this paper. X-ray diffraction, optical microscopy, grain size analysis, total organic carbon, and the concentrations of major, trace, and rare earth elements (REEs) are analyzed in this work. The sandstones are mostly sublitharenite with calcareous cement. The content of the sandstone samples is quartz (39.8%--73.9%), with illite (7.9%--27.6%) and calcite (4.5%--29%). The mineral particles of sandstone samples are mainly well sorted with a fine particle size, suggesting strong paleohydrodynamic force. The value of Si[O.sub.2] is 37.69%--78.19%, followed by [Al.sub.2][O.sub.3] (6.11%--13.67%). Compared with upper continental crust, the boron in the sandstone samples is relatively enriched, whereas Sc, Sr, and Ba are relatively depleted. The [SIGMA]REE content is 124.46-323.99 ppm. Phosphorus is of biogenic origin and enriched by upwelling current. The source of the Xinji Formation sandstone samples was mainly a mixture of sedimentary rock, granite, and alkali basalt, with the provenance of terrestrial clastic materials. The sandstone was deposited under oxic conditions and a warm and humid paleoclimate with saline to brackish features on a passive continental margin. Phosphorus occurring in sandstones is sensitive to paleoclimate and can be used as an indicator to judge paleoclimate, as it is more enriched in warm and humid weather. Key words: geochemistry, paleoenvironment, phosphorus-bearing sandstones, Xinji Formation, Ordos Basin. L'interet croissant pour l'exploration petroliere et gaziere dans des strates d'age cambrien precoce a eu pour consequence d'axer des efforts de recherche sur des gres de cet age. L'origine du phosphore et le paleomilieu de gres contenant du phosphore de la Formation de Xinji sont examines. La diffraction X, la microscopie optique, l'analyse granulometrique, ainsi que l'analyse du carbone organique total et des concentrations d'elements majeurs et en traces et des terres rares ont ete effectuees. Les gres sont pour la plupart des sublitharenites a ciment calcareux. Les teneurs des echantillons de gres en quartz sont de 39,8-73,9 %, avec de l'illite (7,9-27,6 %) et de la calcite (4,5-29 %). Les grains de mineraux sont principalement bien classes et de granulometrie fine, ce qui indiquerait de grandes forces paleohydrodynamiques. Les teneurs en Si[O.sub.2] sont de 37,69-78,19 %, suivies de l'[Al.sub.2][O.sub.3] (6,11-13,67 %). Par rapport a la croute continentale superieure, le bore est relativement enrichi dans les echantillons de gres, alors que le Sc, le Sr et le Ba sont appauvris. Les concentrations en terres rares totales ([SIGMA]REE) sont de 124,46 ppm--323,99 ppm. Le phosphore est d'origine biogenique et enrichi par des courants de remontee. La source des gres etudies de la Formation de Xinji etait principalement constituee d'un melange de roche sedimentaire, de granite et de basalte alcalin, la provenance des materiaux clastiques etant terrestre. Les gres se sont deposes dans des conditions oxydantes et chaudes, dans un paleoclimat humide et dans un milieu de marge continentale passive caracterise par des eaux salines a saumatres. Le phosphore dans les gres est sensible au paleoclimat et peut etre utilise comme indicateur de ce dernier, son enrichissement refletant des conditions meteorologiques chaudes et humides. [Traduit par la Redaction] Mots-cles: geochimie, paleomilieu, gres contenant du phosphore, Formation de Xinji, bassin d'Ordos., Introduction The Ordos Basin is the largest petroliferous basin in China (Zhang 2000; Hou et al. 2003; Xi et al. 2006; Liu et al. 2009; Shi et al. 2009). Current [...]

With the rapid development of the internet economy, many manufacturers have opened online direct sales channels and built multi-channel distribution systems. Meanwhile, both consumers and companies are paying more attention to extended warranty services. Considering a dual-channel supply chain with a manufacturer and a retailer, we assume the manufacturer provides an extended warranty in the online direct channel and investigates the decision making of the supply chain players. We develop three game models to study this problem, and they are the basic model without extended warranty (Model B), the decentralized decision model with the manufacturer's extended warranty (Model M), and the centralized decision model with the manufacturer's extended warranty (Model C). The Stackelberg game method is used to solve the established model, the influence of relevant parameters on the solution result is analyzed, and different models are compared. Compared with Model B, we find that the whole supply chain always be better, but the retailer would be worse in Model M. Compared with Model M, we find that the entire supply chain always performs better in Model C. Finally, we do some sensitivity analysis. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) has been widely investigated in optoelectronic devices because of its non-toxicity, high optical absorption coefficient, intrinsic p-type conductivity, and high hole mobility. However, misaligned energy levels remain an obstacle to obtaining efficient optoelectronic devices due to the extremely high conduction band minimum of Cu2O. Here, a band-aligned wide bandgap Ga2O3 buffer layer is introduced and a graded heterojunction ZnO/Ga2O3/Cu2O is realized. The oxygen-vacancy concentration and therefore the Fermi level, optical transmittance, and bandgap of the Ga2O3 films can be tuned by controlling the oxygen environment during pulsed laser deposition. The performance of the optoelectronic devices is improved by incorporating an optimized Ga2O3 buffer layer deposited at 1 Pa oxygen pressure with a deposition temperature of 100 °C. Photodetectors with a response range from the near-ultraviolet to the visible-light region, good linearity, fast response, and excellent long-term stability are demonstrated. In the meantime, an enhancement of the external quantum efficiency of 66% was reached by inserting the Ga2O3 buffer layer. Heterojunctions with gradient energy bands are confirmed to be effective in accelerating charge transport and suppressing carrier recombination through Kelvin probe force microscopy (KPFM) studies. Our work provides a new approach for developing self-powered ultraviolet and visible-light photodetectors with low-cost and high stability. [ABSTRACT FROM AUTHOR]

P‐type semiconductor cuprous oxide (Cu2O) offers promising optoelectronic applications such as solar cells and photodetectors owing to its considerable absorption coefficients and high carrier mobility. However, polycrystalline Cu2O films with low carrier mobility resulting from excessive grain boundaries and structure disorder fail to meet the demands for these optoelectronic applications. Here a stress‐assisted thermal oxidation method to fabricate p‐type <110>‐textured quasi‐single crystalline Cu2O (c‐Cu2O) wafers with centimeter‐scale grains is developed. It is found that strain energy induced by thermal contact stress plays a critical role in crystal growth. The resultant <110>‐textured quasi‐single c‐Cu2O wafers exhibit excellent crystallinity with rocking curve having a low full width at half maximum of 0.022°, a low defect density of 2 × 1011 cm−3, a high mobility exceeding 100 cm2 V−1 s−1, and a long minority lifetime of 98.5 µs. Such quasi‐single c‐Cu2O wafers lead to efficient solar cells with an open‐circuit voltage of 0.95 V and highly responsive photodetectors with superior cycling stability. These results indicate not only the advancement of fabricating high‐quality Cu2O wafers upon controllable methodology but also the promising optoelectronic applications using p‐type metal oxide semiconductors. [ABSTRACT FROM AUTHOR]