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•Cobalt mineralization is associated with metal sulfides, which develop at the sulfide stage.•The isomorphic substitution of Co in the Lalingzaohuo deposit is an important potential ...available resource.•The East Kunlun Orogenic Belt is an important cobalt-bearing skarn mineralization potential region.
The Lalingzaohuo cobalt-bearing Cu polymetallic skarn deposit, located in the central part of the East Kunlun Orogenic Belt, is mainly hosted in the Paleoproterozoic Jinshuikou Group. The occurrence and genesis of cobalt at Lalingzaohuo were investigated by field geology, mineralogy, geochronology, and electron probe microanalyses (EPMA), that these data provide some insights into the ore-forming process and also show the key characteristics of a cobalt-bearing skarn. Garnet U-Pb dating yielded a lower intercept 206Pb/238U date of 207.5 ± 4.9 Ma, younger than spatially related quartz diorite (SHRIMP zircon U–Pb dating, 246.8 ± 1.7 Ma), which suggested that the Lalingzaohuo was formed during the Late Triassic. Photomicrographs and EPMA data confirm that Co mineralization is associated with metal sulfides, which develop at the sulfide stage. Cobalt occurrence in Lalingzaohuo is restricted to Co mineral (cobaltite) and other metal sulfides (pyrite, pyrrhotite, chalcopyrite, and sphalerite) where isomorphic substitution occurred. Cobaltite is mainly distributed at the periphery of the skarn alteration zone with more pyroxene. The isomorphic substitution content of Co in pyrite (2.43–3.05 wt%), pyrrhotite (1.87–2.47 wt%), chalcopyrite (0.63–1.38 wt%), and sphalerite (0.73–0.90 wt%) is high. The negative correlation between Co + Ni (wt.%) and Fe (wt.%) suggests that Co + Ni replaces Fe in pyrite and pyrrhotite. The weak correlation between Co (wt.%) and Cu or Fe (wt.%) indicates that only part of the isomorphic Co in chalcopyrite is carried out by substituting Fe and Cu. The high Fe and Co content in sphalerite indicate that Co + Fe replaces Zn by isomorphic substitution. The isomorphic substitution of Co in the Lalingzaohuo deposit is an important potential available resource. Based on the magmatic activity records, the Triassic Lalingzaohuo deposit was formed under an extensional environment, which is related to the subduction of the branch of the Paleo-Tethyan Ocean. This study together with the regional developed cobalt-bearing skarn deposits indicates that the East Kunlun Orogenic Belt is an important cobalt-bearing skarn mineralization potential region.
In this study, the effect of a MgO interfacial layer on the electrical characteristics of an ovonic threshold switching (OTS) device was investigated. Compared to the control OTS device, the device ...with the MgO interfacial layer showed excellent switching uniformity and ultralow off-state leakage current (<inline-formula> <tex-math notation="LaTeX">\sim 440 </tex-math></inline-formula>pA) without noticeable changes in the electrical forming process. By extracting the activation energy before and after the forming process, we confirmed that the enhanced switching characteristics were obtained by reducing the interaction between the OTS film and electrodes. Furthermore, the 1S-1R operation with TaO x -based resistive random access memory (ReRAM) showed successful suppression of the leakage current, which is suitable for a cross-point memory array application.
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•Three stages of pyrite are identified in Qingshan gold deposit.•The results of LA-ICP-MS trace element analyses indicate that invisible gold occurs in the form of solid solution ...(Au+), and the mixing of fluids is most likely the reason for gold precipitation.•The results of in situ S-Pb isotopic indicate that sulfur and metals were mainly derived from the upper crust and orogenic belts.
The Qingshan gold deposit is located in the Tanjianshan ore collection area, which is in the northern margin of Qaidam Basin and is one of the most important gold and polymetallic metallogenic belts in China. Based on the field investigation and optical microscopic observations, mineralization at the Qingshan deposit can be divided into three stages: (1) quartz-pyrite stage, (2) quartz-sulfide-gold stage, (3) quartz-calcite stage. Pyrite from the stage 1 (Py1), stage 2 (Py2) and stage 3 (Py3) are selected for LA-ICP-MS trace element analyses. Pyrite from the stage 1 (Py1), stage 2 (Py2) are selected for in situ sulfur isotopes analysis. Pyrite from the stage 1 (Py1), stage 2 (Py2) and stage 3 (Py3), galena from the stage 1 (Gn1) and stage 2 (Gn2) are selected for in situ lead isotopes analysis. The result shows that Py1 is relatively rich in Co, Ni, Zn and Ag contents and lacking in Sb contents. Py2 is relatively rich in Cu, As, Sb, Au, Pb and Ag contents and lacking in Co, Ni and Bi contents. Py3 is relatively rich in Co, Ni and Bi contents and lacking in Zn, As, Au and Pb contents. The Au/As ratio shows that invisible gold occurs in the form of solid solution (Au+). The values of Au/Ag and Co/Ni ratio show that the pyrites in the Qingshan deposit are hydrothermal origin. The S isotope values of pyrite range from −4.33 to 4.97‰ (mean: 3.71‰, n = 31). The Pb isotope compositions with 206Pb/204Pb, 207Pb/204Pb, and 208Pb/204Pb values ranging from 18.002 to 18.791, 15.567 to 15.584, and 38.410 to 38.485, respectively. The results of in situ S-Pb isotopic indicate that sulfur and metals of the Qingshan deposit were mainly derived from the upper crust and orogenic belts. The Qingshan gold deposit is classified as an orogenic gold deposit, and was closely related to a large-scale ductile shear zone, which formed during the process of subduction between the Qaidam block and the Qilian block in the Variscan period. The mixing of fluids destroyed the stability of Au(HS)2- and is most likely the reason for gold precipitation.
Purpose
This paper aims to analyze the relationships between discourse leading indicators and citations from perspectives of integrating altmetrics indicators and tries to provide references for ...comprehending the quantitative indicators of scientific communication in the era of open science, constructing the evaluation indicator system of the discourse leading for academic journals and then improving the discourse leading of academic journals.
Design/methodology/approach
Based on the theory of communication and the new pattern of scientific communication, this paper explores the formation process of academic journals' discourse leading. This paper obtains 874,119 citations and 6,378,843 altmetrics indicators data from 65 international multidisciplinary academic journals. The relationships between indicators of discourse leading (altmetrics) and citations are studied by using descriptive statistical analysis, correlation analysis, principal component analysis, negative binomial regression analysis and marginal effects analysis. Meanwhile, the connotation and essential characteristics of the indicators, the strength and influence of the relationships are further analyzed and explored. It is proposed that academic journals' discourse leading is composed of news discourse leading, social media discourse leading, peer review discourse leading, encyclopedic discourse leading, video discourse leading and policy discourse leading.
Findings
It is discovered that the 15 altmetrics indicators data have a low degree of centralization to the center and a high degree of polarization dispersion overall; their distribution patterns do not follow the normal distributions, and their distributions have the characteristics of long-tailed right-peaked curves. Overall, 15 indicators show positive correlations and wide gaps exist in the number of mentions and coverage. The academic journals' discourse leading significantly affects total cites. When altmetrics indicators of international mainstream academic and social media platforms are used to explore the connotation and characteristics of academic journals' discourse leading, the influence or contribution of social media discourse, news discourse, video discourse, policy discourse, peer review discourse and encyclopedia discourse on the citations decreases in turn.
Originality/value
This study is innovative from the academic journal level to analyze the deep relationships between altmetrics indicators and citations from the perspective of correlation. First, this paper explores the formation process of academic journals' discourse leading. Second, this paper integrates altmetrics indicators to study the correlation between discourse leading indicators and citations. This study will help to enrich and improve basic theoretical issues and indicators’ composition, provide theoretical support for the construction of the discourse leading evaluation system for academic journals and provide ideas for the evaluation practice activities.
In this study, a combination of experimental and statistical methods were employed to precisely determine the micro channel depth in ultra-thin metallic bipolar plates fabricated from 316 stainless ...steel with a thickness of 0.1 mm. The investigation centers on the rubber pad forming process and its role in the production of these critical components for Proton Exchange Membrane Fuel Cells (PEMFCs). To advance the understanding of this manufacturing process, experimental tests were designed using a Design of Experiment (DOE) technique and subsequently developed a predictive model using Response Surface Methodology (RSM). The research reveals a direct, quantifiable relationship between the channel depth in metallic bipolar plates and the magnitude of the applied force. Also, the pivotal role of rubber thickness as a dominant factor influencing channel depth was explored. Furthermore, it is revealed that augmenting the channel depth in these plates is attainable through a reduction in rubber hardness and an increase in rubber thickness. However, the benefits diminish once the rubber layer thickness exceeds a specific threshold. Moreover, the results underscore that the primary influential factors in this process include force, hardness, thickness, as well as the interplay between force and rubber thickness. The proposed model's accuracy is reaffirmed through an average error rate of approximately 5.39%, signifying its reliability in predicting microchannel depth. This research contributes novel insights into the manufacturing of ultra-thin metallic bipolar plates for PEMFCs, shedding light on the critical parameters influencing channel depth and their interrelationships. The significance and engineering value of this work lies in its potential for enhancing the design and manufacturing of metallic bipolar plates for PEMFCs. Precise control of microchannel dimensions is crucial for enhancing PEMFC performance and efficiency. This research not only advances clean energy technology but also contributes to the broader goal of achieving sustainable energy solutions, making it a noteworthy and timely contribution to the field.
To improve forming simulation outcomes for composite prepregs and predict wrinkle formation, the bending behavior of prepreg materials must be correctly characterized. This paper proposes a new ...loading-rate control bending test in which the sample deflection and applied rate are controlled by a linear actuator while the load required to achieve this deflection is recorded by a miniature-load cell. An investigation of out-of-plane bending behavior as well as viscoelastic behavior at the forming process conditions of woven fabric out-of-autoclave prepregs was undertaken using this method. The experimental results show that the proposed bending test provides sufficient control of the deflection shape, testing rates, and processing temperatures within the range of thermosetting resin. Furthermore, the bending results reveal the rate dependency and viscoelastic nature of the materials. A method is developed to derive the bending stiffness from the nonlinear relationship between bending moment and curvature.
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•Samples from the contact zone between ore body and dolostone are used to characterize ore-forming process.•Textural and chemical composition of dolomite indicate intensive fluid-rock ...interaction.•Systematic S and Pb isotope variations of sulfides reflect various replacement of dolostone and precipitation of sulfides.•The pH change has played an important role in ore deposition.•A new model for the ore-forming process was proposed for the Huize deposit.
Study on the ore-forming process is crucial for comprehending the mechanisms of metal enrichment and facilitating mineral exploration. The Huize deposit in southwestern China is characterized by significant Pb and Zn resources, as well as economic coproducts of Ge and Ag. In spite of extensive studies, the key factors for ore deposition remain controversial. Mineral textures, in situ trace elements of dolomite, and S and Pb isotopes of sphalerite and galena from the contact zone between ore body and wall rocks were used to decipher this issue. The contact zone samples are further divided into three parts at the thin section scale: ore, transitional zone, and wall rock dolostone. In the ore part, dolomite is characterized by irregular replacement. In the transitional zone, dolomite displays a core-rim texture with dolomite in the core and Fe- and Mn-rich dolomite in the rim. In the wall rock part, the Fe- and Mn-rich dolomite occur as veins. From the ore, through the transitional zone, to the wall rock, the contents of Ca, Mg, and rare earth elements in dolomite increased, whereas the contents of Mn, Fe, In, and V decreased, indicating interaction between ore-forming fluids and dolostone. The LREE depletion of hydrothermal dolomite in three zones is caused by fluid-rock interaction and retention of Cl- complexes. Negative Eu and Ce anomalies indicate that fluids evolve from alkaline to weakly acidic at relatively low temperatures. The δ34S values of sphalerite generally decrease from the ore to the transitional zone, consistent with the kinetic fractionation of sulfur isotopes due to the precipitation of sulfides. The Pb isotopic composition of galena generally increases from the ore, transitional zone, to the wall rock, reflecting increased involvement of dolostone. The detailed ore-forming process can be summarized as follows. When hydrothermal fluids, with higher ore elements, higher δ34S value, and low Pb isotope composition, enter the wall rock that has relatively high Pb isotopic composition, intense fluid-rock interaction occurs, and elements and isotopes are exchanged, forming dolomite-dominated alteration and Pb-Zn sulfides. During this process, the fluids evolve from alkaline to neutral and weakly acidic. Therefore, we suggest that the change in the pH due to the replacement of dolostone has played an important role in ore deposition.
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•Dasuji Mo deposit is a high fluorine and high oxygen fugacity system.•The magma experienced serious fractionation, especially plagioclase and biotite.•Magma evolution promotes the ...enrichment of Mo in residual magma, but not Cu.•The decreased oxygen fugacity causes the precipitation of sulfide.
The Dasuji ore deposit is a large-scale porphyry Mo deposit at the northern margin of the North China Craton, China. Four stages of hydrothermal veins were recognized in the deposit, from early to late: K-feldspar–quartz veins (stage 1), quartz–molybdenite veins (stage 2), quartz–carbonate–pyrite–galena–sphalerite veins and fluorite veins (stage 3), and carbonate–quartz ± fluorite veins (stage 4). The melt inclusions in the earliest K-feldspar–quartz veins retain information about the ore-forming magma. Melt inclusions in quartz were studied in detail to investigate the magmatic evolution. In chondrite- and primitive-mantle-normalized trace element diagrams, all the inclusions have negative Ba, Sr, and Eu, and positive Pb anomalies. The inclusions have uniform (La/Sm)N ratios, and Sr concentrations decrease with decreasing Ba content, indicating the magma experienced significant fractionation, particularly of plagioclase and biotite. With increasing SiO2, Mo concentrations gradually increased, whereas Cu concentrations first increased and then decreased, suggesting that magmatic evolution was beneficial for Mo, but not Cu, enrichment. This indicates that highly fractionated magmas are conducive to the formation of porphyry Mo ore deposits rather than Cu ore deposits. The high F contents in biotite (up to 4.03 wt%) and pervasive occurrence of fluorite are indicative of a high-F magmatic–hydrothermal system. The disappearance of magnetite means the decrease of oxygen fugacity during stage 2, which promotes molybdenite precipitation. The contents of trace elements in fluorite before the stage 4 changed little, indicating that the fluid system was closed prior to this stage. The highly fractionated granitic magmatic system with high oxygen fugacity and high fluorine content potentially contain new porphyry Mo deposit.
To enhance the prediction accuracy of forming simulations of carbon fiber unidirectional (UD) thermoset prepregs, particularly the wrinkle predictions, bending behavior of UD prepregs in the forming ...process needs to be accurately characterized and modelled. In this paper, an improved bending test system was proposed to characterize the bending behavior of UD prepregs at different forming temperatures and loading rates. It is found that both the temperature and the loading rate have significant impact on the bending stiffness of UD prepregs. An obvious nonlinear bending behavior can be noted in the fiber direction. The loading rate sensitivity of bending stiffness in the fiber direction decreases with temperature increasing. To simulate the bending deformation, a superimposed membrane-shell element model was employed to achieve the decoupling of tensile-bending deformation. Membrane element simulated the in-plane tensile and in-plane shear deformations of UD prepregs, while shell element primarily accounted for the bending deformation. Fiber orientation dependent nonlinear bending stiffness was accounted in the model. Deformation simulations were conducted for vertical cantilever bending, horizontal cantilever bending, and compression wrinkling of UD prepregs. Good agreement is noted between simulation and experiment, demonstrating efficiency of the model and validity of measured bending stiffness.
