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[Objective] As an important type of coarse-grained sedimentary system and oil and gas reservoir in faulted basins, fan delta and slump fan complex deposition has been the hot topic of research on lacustrine sedimentary and reservoir formation, such as distribution area, evolution period and accumulation model. [Methods] Based on high resolution 3D seismic and drilling and logging data in the A Sag of Melut Basin in central Africa region, the sedimentary characteristics and evolution of fan delta-slump fan complex are studied by using core observation, sequence division, seismic reflection characteristics and seismic attribute analysis. [Results and Conclusions] The results showed that the types of sedimentary facies of fan in the study area included fan delta and slump fan caused by gravity flow, slump fan had two types of morphology characteristic, the first one was line source slump fan controlled by slope break, the second one was multistage slump fan with single point source controlled by steep topographic slope. Combined with seismic profiles and well logging features, five periods of fans were recognized in the Cretaceous study section. The single-stage fan all had the characteristics of retrogradation, the vertical evolution of multiple periods of fans was characterized by "first progradation and later retrogradation" . The fan distribution was the largest at the end of Renk Formation deposition in the Lower Cretaceous, reaching 148 km². However, the fan evolution was mainly influenced by tectonic activity, palaeogeomorphology, provenance supply, and base-level cycle. The fan distribution was larger in the period of strong tectonic activity, abundant provenance supply and large short-axis tectonic uplift, and the slump fan was most developed in the early period of relative base-level rising cycle and decreasing cycle. A new understanding of the sedimentary pattern transformation occurred in the Early Cretaceous and Late Cretaceous in the A Sag was put forward. The exploration potential of the fan delta and slump fan complex deposition in the faulted depression is clarified, which guided the exploration deployment. [ABSTRACT FROM AUTHOR]

To maximize the potential energy utilization of agricultural and forestry wastes and sludge, experimental studies were conducted on the co-gasification characteristics of two types of sludge (municipal sludge, MS; paper-mill sludge, PS) and a typical biomass straw (ST) under CO2 atmosphere. In this paper, the main two stages of the gasification process, the pyrolysis in the low-temperature region and the CO2-gasification in the high-temperature region, were separately studied and analyzed. The experimental results showed that biomass could effectively promote the pyrolysis of the sludge in the low-temperature region and improve the gasification in the high-temperature region. Due to the complex interactions between components, the characteristic parameters presented obvious nonlinear rules during the co-pyrolysis and co-gasification processes. For the MS-ST mixtures, when increasing the ST content, (i) in the pyrolysis process, the initial reaction temperature gradually decreased, but the final reaction temperature, the peak reaction rate and the corresponding temperature, and the pyrolysis index gradually increased; (ii) in the gasification process, the initial reaction temperature, the reaction final temperature, and the temperature corresponding to the peak gradually increased. Combined with the reaction kinetics analysis of the co-pyrolysis and the co-gasification processes, 25% may be a reasonable mixing ratio for ST for the MS-ST mixtures, which had a relatively lower reaction temperature, relatively high pyrolysis index and low activation energy (26.58 kJ·mol−1 and 178.29 kJ·mol−1 for the co-pyrolysis and co-gasification processes, respectively). For the PS-ST mixtures, when increasing the ST content, (i) in the pyrolysis process, the initial reaction temperature, the peak reaction rate, the temperature corresponding to the peak and the pyrolysis index gradually decreased, but the final reaction temperature gradually increased; (ii) in the gasification process, the initial and final reaction temperatures and the temperature corresponding to the peak gradually decreased, but the peak reaction rate gradually increased. Combined with the reaction kinetics analysis of the pyrolysis and the gasification processes, 25% may be a reasonable mixing ratio for ST for the PS-ST mixtures, which had a relatively lower reaction temperature, relatively high pyrolysis index and low activation energy (64.29 kJ·mol−1 and 301.16 kJ·mol−1 for the co-pyrolysis and co-gasification processes, respectively). These findings can provide useful information for the co-gasification of sludge and straw under CO2 atmosphere. [ABSTRACT FROM AUTHOR]

A series of Sr3Gd1−xLi(PO4)3F: xSm3+ (x = 0.02, 0.04, 0.06, 0.08) phosphors were synthesized by a high-temperature solid state method. The Sm3+ activated Sr3GdLi(PO4)3F phosphors can be efficiently excited by the wavelengths in the range from 350 to 450 nm, which matches perfectly with that of the commercial near-UV LED chips. The optimal doping concentration of Sr3Gd1−xLi(PO4)3F: xSm3+ phosphors was determined to be x = 0.04, corresponding to the quantum efficiency of 2.23%, and the CIE chromaticity coordinates (x = 0.5172, y = 0.4641). The concentration quenching mechanism of Sm3+ in Sr3GdLi(PO4)3F host is mainly attributed to the dipole-dipole interaction, which was confirmed by the fluorescent lifetimes. The effect of temperature on the photoluminescence property of Sr3GdLi(PO4)3F: Sm3+ was investigated. 90% of the intensity is preserved at 150 °C. In addition, a white light emitting diode (WLED) lamp was fabricated by a 405 nm n-UV LED chip coated with Sr3Gd0.96Li(PO4)3F:0.04Sm3+ phosphor and commercial yellow phosphor (YAG: Ce3+) of a certain mass ratio. The present work indicates that the Sr3GdLi(PO4)3F: Sm3+ orange-red-emitting phosphors tend to be potential application in n-UV WLED. [ABSTRACT FROM AUTHOR]