298 research outputs found

    An oxygen pool from YBaCo4O7-based oxides for soot combustion

    Get PDF
    Acknowledgements This work is financially supported by the National Natural Science Foundation of China (no. 21477046, 21277060 and 21547007). Open Access via RSC Gold4GoldPeer reviewe

    Dense MoS2 Micro‐Flowers Planting on Biomass‐Derived Carbon Fiber Network for Multifunctional Sulfur Cathodes

    Full text link
    The significant challenge in lithium‐sulfur batteries (LSBs) arises from low conductivity of sulfur cathode, loss of active sulfur species due to less anchoring sites and sluggish redox kinetics of lithium polysulfides (LPSs). Herein, the dense MoS2 micro‐flowers assembled by cross‐linked 2D MoS2 nanoflakes planting on biomass‐derived carbon fiber (CF) network (MoS2/CFs) are fabricated as multifunctional sulfur cathodes of LSBs. The 2D MoS2 nanoflakes supported on CF provide abundant anchoring sites for strong adsorption, while the 3D flowerlike structure prevents lamellar aggregation of 2D MoS2 nanoflakes. Importantly, the dense MoS2 micro‐flowers planting on the network weaved by biomass‐derived CFs ensures the high electronic conductivity of the MoS2/CFs composite, sufficient electrode/electrolyte interaction, fast electron and Li+ transportation. Moreover, the CF network weaved from cost‐effective tissue paper reduces the cost of LSBs. Thus, the S‐MoS2/CFs cathode exhibits a high rate capability (1149 and 608 mA h g−1 are obtained at 0.2 C and 4 C, respectively), excellent cyclic performance with ∼75% capacity retention and 99% Coulombic efficiency at 2 C after 500 cycles, corresponding to ∼0.05% capacity fading per cycle only, as well as structure integrity during the discharge/charge process.800 Dong Chuan Road, Minhang District, Shanghai 200240, ChinaA novel, cost‐effective, dense 3 D MoS2 micro‐flowers assembled by cross‐linked 2D MoS2 nanoflakes planting on biomass‐derived carbon fiber (CF) network (MoS2/CFs) are fabricated as multifunctional sulfur cathodes of LSBs. The 2D MoS2 nanoflakes provide abundant anchoring sites for strong adsorption, while the 3D flowerlike structure prevents lamellar aggregation of 2D MoS2 nanoflakes. Significantly, the dense MoS2 micro‐flowers supported on carbon fibers ensures the high electronic conductivity of the MoS2/CFs composite, sufficient electrode/electrolyte interaction, fast electron and Li+ transportation.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155938/1/slct202001729-sup-0001-misc_information.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155938/2/slct202001729_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155938/3/slct202001729.pd

    Comparison of Different Turbulence Models for Numerical Simulation of Pressure Distribution in V-Shaped Stepped Spillway

    Get PDF
    V-shaped stepped spillway is a new shaped stepped spillway, and the pressure distribution is quite different from that of the traditional stepped spillway. In this paper, five turbulence models were used to simulate the pressure distribution in the skimming flow regimes. Through comparing with the physical value, the realizable k-ε model had better precision in simulating the pressure distribution. Then, the flow pattern of V-shaped and traditional stepped spillways was given to illustrate the unique pressure distribution using realizable k-ε turbulence model

    Review: Acid mine drainage (AMD) in abandoned coal mines of Shanxi, China

    Get PDF
    Excessive exploitation and massive coal mine closures have brought about extensive goafs in Shanxi where 8780 coal mines have been abandoned in the last 20 years. Acid mine drainage (AMD) poses severe environmental impact and has become a prominent problem in Shanxi abandoned coal mine areas, which has aggravated the shortage of water resources and threatened the safety of the local drinking water supply. The purpose of this review is to protect the precious water resources and maintain sustainable use in Shanxi coal mines and downstream. By retrieving and analyzing about 90 domestic and international publications, a critical review of the AMD research results in Shanxi abandoned coal mines is conducted from the perspective of the formation mechanism, migration and transformation, prediction, treatment and management. The results shows that pyrite is the prerequisite for the formation of AMD, oxygen is the inducement, water is the carrier, and Fe3+ and microorganisms are the catalyst

    Electrocatalytic conversion of lithium polysulfides by highly dispersed ultrafine Mo2C nanoparticles on hollow N‐doped carbon flowers for Li‐S batteries

    Full text link
    The significant challenge in exploring novel nanostructured sulfur host materials for Li‐S batteries is to simultaneously mitigate the notorious shuttle effect and catalytically enhance the redox kinetics of lithium polysulfides (LPSs). Herein, a novel ultrafine Mo2C nanoparticles uniformly distributed on 2D nanosheet‐assembled 3D hollow nitrogen‐doped carbon flowers (HNCFs) is designed. The Mo2C/HNCFs architecture with unique flower‐like morphologies not only efficiently suppressed the aggregation of 2D nanosheets but also highly distributed the ultrafine Mo2C nanoparticles that act as catalytic active sites for efficient adsorption and conversion of LPSs. Furthermore, the 3D hierarchical arrangement can afford ample internal space to accommodate sulfur species, large volume expansion, 3D electron pathway, and physical/chemical blockage of LPSs to reduce the loss of active materials. The Mo2C/HNCFs composite exhibits a high rate capability, unprecedented capacity retention of 92% over 100 cycles at 0.5 C placing Mo2C/HNCFs one of the best LPSs adsorbents and electrocatalysts.Ultrafine Mo2C nanoparticles on hollow N‐doped carbon flowers have been employed as efficient catalytic active sites for conversion of LPSs, which can not only enhance the LPSs‐adsorption ability but also accelerate the redox kinetics of polysulfide conversion. Besides, the unique architecture of 2D nanosheets assembled 3D hollow N‐doped carbon flowers contributes to Li+ transportation and electrolyte infiltration.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155989/1/eom212020.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155989/2/eom212020_am.pd

    Construction of a 7-fold BAC library and cytogenetic mapping of 10 genes in the giant panda (Ailuropoda melanoleuca)

    Get PDF
    BACKGROUND: The giant panda, one of the most primitive carnivores, is an endangered animal. Although it has been the subject of many interesting studies during recent years, little is known about its genome. In order to promote research on this genome, a bacterial artificial chromosome (BAC) library of the giant panda was constructed in this study. RESULTS: This BAC library contains 198,844 clones with an average insert size of 108 kb, which represents approximately seven equivalents of the giant panda haploid genome. Screening the library with 15 genes and 8 microsatellite markers demonstrates that it is representative and has good genome coverage. Furthermore, ten BAC clones harbouring AGXT, GHR, FSHR, IRBP, SOX14, TTR, BDNF, NT-4, LH and ZFX1 were mapped to 8 pairs of giant panda chromosomes by fluorescence in situ hybridization (FISH). CONCLUSION: This is the first large-insert genomic DNA library for the giant panda, and will contribute to understanding this endangered species in the areas of genome sequencing, physical mapping, gene cloning and comparative genomic studies. We also identified the physical locations of ten genes on their relative chromosomes by FISH, providing a preliminary framework for further development of a high resolution cytogenetic map of the giant panda

    IRF4 suppresses osteogenic differentiation of BM-MSCs by transcriptionally activating miR-636/DOCK9 axis

    Get PDF
    Objectives: Osteoblasts are derived from Bone Marrow-derived Mesenchymal Stem Cells (BM-MSCs), which play an indispensable role in bone formation. In this study, the authors aim to investigate the role of IRF4 in the osteogenic differentiation of BM-MSCs and its potential molecular mechanism. Methods: The authors used lentivirus infection to overexpress IRF4 in BM-MSCs. The expression of IRF4 and osteogenesis-related genes were detected by qRT-PCR and western blot analysis. The osteogenic differentiation of BM-MSCs was evaluated by Alkaline Phosphatase (ALP) activity, Alizarin red staining, and Alkaline Phosphatase (ALP) staining. Chromatin Immunoprecipitation (ChIP), Dual-Luciferase reporter assay and RNA Immunoprecipitation Assay were applied to confirm the regulatory mechanism between IRF4, miR-636 and DOCK9. Results: The authors found IRF4 was down-regulated during the osteogenic differentiation of BM-MSCs, and IRF4 overexpression could decrease the osteogenic differentiation of BM-MSCs by specifically promoting the reduction of Alkaline Phosphatase (ALP) activity and down-regulating osteogenic indicators, including OCN, OPN, Runx2 and CollA1. Mechanistically, IRF4 activated microRNA-636 (miR-636) expression via binding to its promoter region, and Dedicator of Cytokinesis 9 (DOCK9) was identified as the target of miR-636 in BM-MSCs. Moreover, the damage in the capacity of osteogenic differentiation of BM-MSCs induced by IRF4 overexpression could be rescued by miR-636 inhibition. Conclusions: In summary, this paper proposed that IRF4/miR-636/DOCK9 may be considered as targets for the treatment of osteoporosis (OP)

    Selective catalytic reduction of NOx with NH3 over short-range ordered W-O-Fe structures with high thermal stability

    Get PDF
    This work was supported by National Natural Science Foundation of China (Nos. 21477046, 21333003, and 21673072) and Key Technology R&D Program of Shandong Province (No. 2016ZDJS11A03).Peer reviewedPostprintPostprin

    Active Site Identification and Modification of Electronic States by Atomic-Scale Doping To Enhance Oxide Catalyst Innovation

    Get PDF
    This work was supported by National Natural Science Foundation of China (No. 21477046) and Key Technology R&D Program of Shandong Province (No. 2016ZDJS11A03).Peer reviewedPostprin
    corecore