14,364 research outputs found

    Geochemistry and petrogenesis of volcanic rocks from Daimao Seamount (South China Sea) and their tectonic implications

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    The South China Sea (SCS) experienced three episodes of seafloor spreading and left three fossil spreading centers presently located at 18°N, 17°N and 15.5°N. Spreading ceased at these three locations during magnetic anomaly 10, 8, and 5c, respectively. Daimao Seamount (16.6. Ma) was formed 10. my after the cessation of the 17°N spreading center. Volcaniclastic rocks and shallow-water carbonate facies near the summit of Daimao Seamount provide key information on the seamount's geologic history. New major and trace element and Sr-Nd-Pb isotopic compositions of basaltic breccia clasts in the volcaniclastics suggest that Daimao and other SCS seamounts have typical ocean island basalt-like composition and possess a 'Dupal' isotopic signature. Our new analyses, combined with available data, indicate that the basaltic foundation of Daimao Seamount was formed through subaqueous explosive volcanic eruptions at 16.6. Ma. The seamount subsided rapidly (>. 0.12. mm/y) at first, allowing the deposition of shallow-water, coral-bearing carbonates around its summit and, then, at a slower rate (<. 0.12. mm/y). We propose that the parental magmas of SCS seamount lavas originated from the Hainan mantle plume. In contrast, lavas from contemporaneous seamounts in other marginal basins in the western Pacific are subduction-related

    A General Information Theoretical Proof for the Second Law of Thermodynamics

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    We show that the conservation and the non-additivity of the information, together with the additivity of the entropy make the entropy increase in an isolated system. The collapse of the entangled quantum state offers an example of the information non-additivity. Nevertheless, the later is also true in other fields, in which the interaction information is important. Examples are classical statistical mechanics, social statistics and financial processes. The second law of thermodynamics is thus proven in its most general form. It is exactly true, not only in quantum and classical physics but also in other processes, in which the information is conservative and non-additive.Comment: 4 page

    Regenerative potential and functional composition of soil seed banks in remnant evergreen broad-leaved forests under urbanization in South China

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    Soil seed banks can act as an important source in forest regeneration, and the information on the seed bank composition is vital for determining the resilience of plant communities under severe environments such as urban settings. In this study, we examined the seed bank density and functional composition, and their relationships with aboveground vegetation in three remnant evergreen broad-leaved forests, i.e., PuGang (PG), LuoGang (LG), and DaLingShan (DLS) under urbanization in Guangzhou, South China. In both years of our study (2010–2011), seed density and species richness for overall soil seed banks and each classified life forms (tree, shrub, herb and grass) significantly differed among the forests and were much higher in the PG forest. The prevailing life forms in the seed banks were herbs and grasses, and the proportion of tree species Importance Value index (IV) of the seed banks was low. We did not detect significant difference in the percentage of exotic species seeds in the seed banks among the forests. The proportion of species with animal dispersal mode was much higher in the DLS forest than in the PG and LG forests. The similarity in species composition between standing vegetation and seed banks was low with the lower value in the DLS forest than in PG and LG forest. Our findings suggest that the regeneration potential of the soil seed banks is limited for the remnant forests in urban areas. Therefore, greater proactive and enhanced conservation efforts are thus needed

    A new 111 type iron pnictide superconductor LiFeP

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    A new iron pnictide LiFeP superconductor was found. The compound crystallizes into a Cu2Sb structure containing an FeP layer showing superconductivity with maximum Tc of 6K. This is the first 111 type iron pnictide superconductor containing no arsenic. The new superconductor is featured with itinerant behavior at normal state that could helpful to understand the novel superconducting mechanism of iron pnictide compounds.Comment: 3 figures + 1 tabl

    Endoood: Uncertainty-Aware Out-of-Distribution Detection in Capsule Endoscopy Diagnosis

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    Wireless capsule endoscopy (WCE) is a non-invasive diagnostic procedure that enables visualization of the gastrointestinal (GI) tract. Deep learning-based methods have shown effectiveness in disease screening using WCE data, alleviating the burden on healthcare professionals. However, existing capsule endoscopy classification methods mostly rely on predefined categories, making it challenging to identify and classify out-of-distribution (OOD) data, such as undefined categories or anatomical landmarks. To address this issue, we propose the Endoscopy Out-Of-Distribution (EndoOOD) framework, which aims to effectively handle the OOD detection challenge in WCE diagnosis. The proposed framework focuses on improving the robustness and reliability of WCE diagnostic capabilities by incorporating uncertainty-aware mixup training and long-tailed in-distribution (ID) data calibration techniques. Additionally, virtual-logit matching is employed to accurately distinguish between OOD and ID data while minimizing information loss. To assess the performance of our proposed solution, we conduct evaluations and comparisons with 12 state-of-the-art (SOTA) methods using two publicly available datasets. The results demonstrate the effectiveness of the proposed framework in enhancing diagnostic accuracy and supporting clinical decision-making

    Study on the heat transfer reinforcement of glass fiber/epoxy resin composites by grafting and dispersing graphene oxide

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    The grafted-graphene oxide/glass fiber/epoxy resin (grafted-GO/GF/EP) and dispersed-graphene oxide/glass fiber/epoxy resin (dispersed-GO/GF/EP) composites were successfully prepared by grafting graphene oxide (GO) on glass fiber (GF) with coupling agent and random dispersion of GO. A scanning electron microscope (SEM) was employed to characterize the micro structure. The heat transfer RVE models of the grafted-GO/GF/EP and dispersed-GO/GF/EP composites were established respectively. Based on RVE heat transfer simulation model, the heat transfer characteristics of the grafted-GO/GF/EP and dispersed-GO/GF/EP composites were analyzed. The results show that under the condition of 0.1 vol% GO content and heated for 60 s, the thermal conductivities of dispersed-GO/GF/EP and grafted-GO/GF/EP composites are increased by 3.48% and 82.37% respectively. The dispersion of GO increases the heat transfer paths in EP and forms a connected GO-GO heat transfer network. However, with the increasing of GO content, the agglomeration of GO becomes more obvious. The dispersion and interfacial bonding of the GO/GF/EP composites were improved by coupling agent, which effectively reduced the interfacial thermal resistance and significantly improved the thermal conductivity of the composites
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