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[en] Based on observations made on cores and cuttings from several wells in the lowermost part of the third member of the Shahejie Formation, several rock types, specifically clast-supported rudstone, matrix-supported rudstone, mixed-source rudstone, calcisiltite/calcarenite, massive calcilutite and laminated calcilutite, have been identified in the Shulu sag. According to the sedimentary structures and distribution characteristics of these rocks, the carbonate breccias fall into two categories, based on their origins: one formed by fan-delta channel sedimentation, whereas the other formed by earthquake-induced slump fan deposition. Clast-supported rudstone and matrixsupported rudstone are the main lithologies deposited by braided rivers in the fan delta plain and front, of which the pore space is mainly dissolution pores within gravels and tectonic fissures. Clastsupported rudstone, matrix-supported rudstone and mixed-source rudstone are the main lithologies of the earthquake-induced slump fans. These carbonate breccias developed along with soft-sediment deformation structures, which are interpreted as seismites and are widely distributed in the sag, in which intercrystalline pores, intergranular pores and fissures created from diagenetic shrinkage are developed. The two kinds of rudstones have different reservoir characteristics and oil/gas testing results. The rudstones generated in the fan delta have higher porosity and permeability, as well as better oil/gas testing results. Thus, they are key targets for petroleum exploration.
[en] Radiolarites have an important role in the reconstruction of the paleogeography, bathymetry and their coexistence with ophiolites gives an opportunity to determine the tectonic history of collisional zones. The radiolarite units of the southwestern Neyriz are part of the Zagros accretionary prism and positioned beneath the thick bedded carbonate sediments of Tarbur Formation. The existing various structural elements within this unit give a unique fortunate for investigation on the deformation history and studying of the kinematics of the Zagros collision zone. The numerous evidence show that this unit has experienced different deformation conditions during ongoing evolution, including ductile, brittle-ductile and brittle deformation conditions. The main strike of E-W for axial planes of folds, eastward trend and plunge of fold axes, boudins’ neck axes and Type III of the fold interference patterns are indicators of formation and evolution of folds during transpressional deformation. Structural evolution of the study area has been affected by an NE-dipping subduction zone of Neo-Tethyan oceanic lithosphere below the Iranian microcontinents. These structural elements suggest that high mechanical anisotropy and two successive generations of folding simultaneously with thrusting and extrusion of this unit had led to formation and evolution of this highly asymmetrical folded unit on top of the subducted oceanic crust.
[en] Shadong deposit is the first large-scale tungsten deposit found in the East Tianshan orogenic belt, and the geologic characteristics of the deposit indicate that the deeply concealed granite body is genetically related with the mineralization. The LA-ICPMS U-Pb age of zircons from the Shadong concealed granite obtained in this research is 239±2.0 Ma, belonging to the Middle Triassic. The whole rock samples are metaluminous to slightly peraluminous (A/CNK=0.95–1.02) with low contents of SiO2 (64.0 wt.%–68.5 wt.%) and low K2O/Na2O ratios (0.73–0.96). The samples reveal enrichment of K, Rb, Th and depletion of Nb, Ta, P, Ti and have a negative slope from La to Lu (LaN/YbN=16.29–36.8) with weak negative Eu anomaly (Eu/Eu*= 0.71–0.82). Initial 87Sr/86Sr ratios of whole rock range of 0.706 59–0.707 75, εNd(t) values range from -1.77 to -2.53 and εHf(t) values of zircon are between 2.54 and 4.90. The lithogeochemistry and Sr-Nd-Hf isotopic characteristics revealed that the concealed granite in Shadong tungsten deposit is I-type granite, and occurs in an intraplate tectonic setting. The magma mixing during intraplating of mantle derived magma intruding into the crust in Indosinian Period is the major formation mechanism of the granite. Of which, the proportion of mantle derived magma ranges from 58% to 60%, and the crustal materials are mainly the metamorphic basement of Xingxingxia Group of Mesoproterozoic Changcheng System, which may provide the main source of ore forming metals of Shadong tungsten deposit.
[en] The plate affiliation of the North Dabie terrane (NDT) has been controversial. To address this fundamental question, an integrated study of internal structure, in-situ U-Pb dating and trace element analysis in zircons and field investigation for migmatite in the NDT was carried out, which reveals participation of crustal rocks of the North China craton (NCC) in the protolith in addition to the more common crustal rocks of the Yangtze craton (YC). The evidence of an NCC affinity for protolith of migmatite in the NDT is the ∼2.5 Ga (2 486±14 and 2 406±26 Ma) magamtic age and ∼1.8 Ga (1 717±79 Ma) metamorphic age in the relict zircon domains because these two age groups are characteristic for the evolution of the NCC. The evidence of a YC affinity for protolith of migmatite in the NDT is the more common 0.7–0.8 Ga (e.g., 787±12 Ma) magamtic zircon age. Mid-Neoproterozoic magmatic age (0.7–0.8 Ga) is a symbol of YC basement rocks. In view of the widely exposed YC crustal components in the NDT, we suggest that the protolith of the NDT is mainly crustal rocks from the YC with minor crustal components from the NCC. The zircon rim domains and new growth grains from all the migmatite samples are characterized by anatectic zircons and have a widely concordant ages ranging from 112.2±2.8 to 159.6±4.3 Ma with several peak values, suggesting a long lasting multistage anatexis. In conclusion, the NDT has a mixed protolith origin of both the YC and the NCC crustal rocks were strongly remoulded by anatexis during orogenic collapse.
[en] The radial sand ridge system (RSRS) located at Jiangsu coast of China attracts much attention on its origin and mechanic of formation for its special structure and potential land resource. Due to complicated hydrodynamic condition, the Jiangsu RSRS is a hot debated on its potential sources, Yangtze River or Yellow River? We collected ten sand samples from surface sediments along the west coast of Bohai Sea and Yellow Sea from the modern Yellow River estuary to Yangtze River estuary in summer, 2013. The samples are analyzed by method of detrital zircon age for source identification of the RSRS sediments. The U-Pb age spectra of detrital zircon grains of the samples show a wide range from Cenozoic to Late Archean with several age peaks. Comparing the age spectra between the Yangtze River and the Yellow River, the detrital zircons have younger age (<100 Ma) group in the Yangtze River. These age distribution of the Jiangsu coastal RSRS sediments are similar to that of the Yangtze River, but different from the Yellow River. The samples located adjacent to the old Yellow River Delta show more wide-range age distribution, implying a compounded origination from the both rivers. Based on these findings it is proposed that, contrary to common opinion, the main sediment source of the Jiangsu RSRS is the Yangtze River, rather than the Yellow River. By implication, there should be evidence of hydrodynamic mechanics of oceanic currents and tidal motion. This aspect awaits confirmation in future research.
[en] Using well logs data only, the evaluation of shale gas hydrocarbon potential of Talhar Shale Member of Lower Goru Formation has been a challenge in Southern Lower Indus Basin in Pakistan. Well logs data analysis is helpful to evaluate the gas potential of source shale rocks. We introduced and applied empirical and graphical method to fulfil this task and derived geochemical parameters from well logs data. The method mentioned is cheap and fast. Talhar Shale has kerogen type III and type II which are montmorillonite clay and have potential to produce oil and gas. Talhar Shale has better sorption property. Empirical formulas are used to derive parameters, using well logs of porosity, density and uranium. Porosity and volume of kerogen, calculated from density log, give average values of 11.8% and 11.4%. Average value of level of maturity index (LMI) derived from log is 0.54, which indicates that it is at the early stage of maturity. Vitrinite reflectance is between 0.5%–0.55% as calculated by graphical method and empirical formula. Talhar Shale is at onset of oil generation, with main products of oil and gas. It is a good potential source in the study area.
[en] Currently, the most important challenge for solar energy photo-thermal utilization is the thermal stability of solar absorber coatings at high temperature. The new one-layer nano-composite TiN/TiC-based cermet coatings were designed and fabricated with laser-cladding method in the air. The result indicated the laser cladding could be used to obtain 30 wt.%, TiN-30 wt.%, TiC-20 wt.%, and Ni-20 wt.% Mo cermet coatings with the desired optical properties. In particular, an absorptance (α) of ~80.1% and a thermal emissivity (ε) of ~2% at 300 K were calculated when the weight rate of nano-particles/micro-particles is 1:1. In addition, the thermal stability of the coating was outstanding after heat treatment at 650 °C for 6 h. The absorptance and emissivity of cermet coating were, respectively, 80.8% and 1.9% at 650 °C. The results indicated that nano-composite TiN/TiC-Ni/Mo cermets are suitable for spectrally selective materials. Moreover, the laser cladding was found to be an improved and novel preparation method in the field of solar-selective-absorbing coatings.
[en] Quantum dots are drawing great attention as a material for the next generation solar cells because of the high absorption coefficient, the tunable bandgap, and multiple excitons’ generation effect. In this paper, Ag ions doped on the CdSe quantum dot by mixing molar concentrations of 0.005 M, 0.01 M, 0.015 M, 0.02 M, and 0.026 M of AgNO with Cd(CHCOO)·2HO anion source. TiO2/CdSe:Ag multiple layers were obtained by the successive ionic layer absorption and reaction, as the TiO film was dipped in the CdSe:Ag quantum-dot solution. The morphological observation and crystalline structure of photoanode films were characterized by the field-emission scanning electron microscopy and X-ray diffraction. The electrochemical performance of photoelectrode was studied using the electrochemical impedance spectra. As a result, we have succeeded in designing a cell with the high efficiency of 2.72%. In addition, the optical properties, the direct optical energy gap, and both the conduction band and valence band levels of the compositional CdSe:Ag were estimated using theory of Tauc and discussed details. This theory is useful for us to understand the alignment energy structure of the compositions in photoelectrodes, in particular, the conduction band and valence band levels of CdSe: Ag nanoparticles.
[en] In this study, Ba-doped γ-CeS was successfully prepared via a co-precipitation reaction method using Ce (NO)·6HO, Ba (NO), (NH)CO, and CS as raw materials. The effects of different molar ratios of Ba to Ce (n = 0-0.6) on the phase composition, chromaticity, and thermal stability of γ-CeS were systematically investigated. Pure γ-CeS was obtained by calcining samples with the Ba/Ce molar ratio 0.1-0.5 at 900 °C for 150 min. Under the same conditions, the undoped samples exhibited a pure α phase, while for the Ba/Ce ratio of 0.6, a new heterogeneous phase, BaS formed. As nBa/Ce increased, the band gap of γ-CeS increased from 2.06 to 2.31 eV, which led to the color change from red to orange–red and finally, to yellow. The redness value a* reaches a maximum (L* = 33.51, a* = 37.07, b* = 27.18) when n = 0.1. The samples with n = 0.1 still presented the γ phase and showed excellent chromaticity (L* = 30.10, a* = 25.33, b* = 12.71) after heat treatment at 440 °C for 10 min in air. The results fully show that Ba doping filled the internal vacancies of γ-CeS solid solution, which was beneficial for the stability of its lattice, thus improving the thermal stability of γ-CeS (from 350 to 440 °C).
[en] Ni–P–B coatings are produced directly on surface of carbon steel (AISI 1040) using electroless plating technique. The effects of temperature on the friction and wear behavior of Ni–P–B alloy coatings have been investigated. Tribological tests are conducted at four temperatures (30, 100, 300 and 500 °C) under constant load and sliding speed in a pin-on-disk apparatus. Results show that Ni–P–B coatings sustain the elevated temperatures with minimal effect on friction and wear performances. Ni–P–B coating is found to exhibit the maximum hardness among the binary Ni–P and Ni–B coatings with as-deposited hardness reaching around 700 HV. Heat treatment increases the hardness as well as wear resistance by precipitation of boride and phosphide phases of nickel. Room temperature test shows mostly adhesive wear pattern but finally, it leads to a mixture of abrasive–adhesive wear mechanism. Friction and wear of Ni–P–B is overall governed by the formation of oxidative layer, mechanically mixed layer with iron (from ferrous counter face), wear mechanism, phase transformation and changes in microstructure during elevated wear test. Phase transformation and corresponding micro-structural changes occurring during elevated test duration help in providing better wear resistance to the coating.