76 research outputs found

    Engineering high-emissive silicon-doped carbon nanodots towards efficient large-area luminescent solar concentrators

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    Luminescent solar concentrators (LSCs) are devices that can collect sunlight from a large area, concentrating it at the borders of the slab, to achieve efficient photovoltaic conversion when small area solar cells are placed at their edges, realizing building-integrated photovoltaics. Efficient luminophores in terms of high luminescence quantum yield are needed to obtain high-performance LSCs. A key point is the ability to engineer the Stokes shift (i.e. the difference between the maximum of the absorption and emission spectra), to minimize reabsorption processes. In this work, we report novel silicon-doped carbon nanodots (Si-CDs) with an ultrahigh quantum yield (QY) up to 92.3% by a simple hydrothermal method. Thin-film structured LSCs (5 × 5 × 0.2 cm3) with different concentrations of Si-CDs are prepared by dispersing the Si-CDs into polyvinyl pyrrolidone (PVP) matrix, and the optimal power conversion efficiency (PCE) of LSCs can be as high as 4.36%, which is nearly 2.5 times higher than that prepared with silicon-undoped CDs. This Si-CDs/PVP film LSC has a high QY of 80.5%. A large-area LSC (15 × 15 cm2) is also successfully fabricated, which possesses a PCE of 2.06% under natural sunlight irradiation (35 mW·cm−2), one of the best reported values for similar size LSCs. The efficient Si-CDs as luminescent substances for high-efficiency large-area LSCs will further give an impetus to the practical exploitation of LSCs

    Evaluation Research of Traction Motor Performance for Mine Dump Truck Based on Rough Set Theory

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    This paper presents the traction motor evaluation method depending on the electric transmission energy transfer characteristics and different source of supply, including motor manufactures, diesel turbine manufacturers, wheel side reducer manufacturers and electric drive system integrated manufacturers. 9 evaluations are proposed in 3 levels from the motor body and control performance, electric drive system coordinate index, driving conditions and specific cycle. Motor performance evaluation system is published by the means of electric transmission tests and computer simulation platform, using rough set theory. Experimental results show that the model can accurate evaluation of state of the traction motor, Evaluation of the accuracy is better than the subjective weighting analysis, verifying the integrity and usefulness of this valuation method. At the same time, the comprehensive evaluations index of permanent magnet synchronous motors is high, it has important research value.

    Minimal flag triangulations of lower-dimensional manifolds

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    We prove the following results on flag triangulations of 2- and 3-manifolds. In dimension 2, we prove that the vertex-minimal flag triangulations of RP2\mathbb{R} P^2 and S1×S1\mathbb{S}^1\times \mathbb{S}^1 have 11 and 12 vertices, respectively. In general, we show that 8+3k8+3k (resp. 8+4k8+4k) vertices suffice to obtain a flag triangulation of the connected sum of kk copies of RP2\mathbb{R} P^2 (resp. S1×S1\mathbb{S}^1\times \mathbb{S}^1). In dimension 3, we describe an algorithm based on the Lutz-Nevo theorem which provides supporting computational evidence for the following generalization of the Charney-Davis conjecture: for any flag 3-manifold, γ2:=f1−5f0+16≥16β1\gamma_2:=f_1-5f_0+16\geq 16 \beta_1, where fif_i is the number of ii-dimensional faces and β1\beta_1 is the first Betti number over a field. The conjecture is tight in the sense that for any value of β1\beta_1, there exists a flag 3-manifold for which the equality holds.Comment: 6 figures, 3 tables, 19 pages. Final version with a few typos correcte

    Pressure-induced superconductivity in quasi-one-dimensional semimetal Ta2PdSe6\mathrm{Ta}_2 \mathrm{PdSe}_6

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    Here we report the discovery of pressure-induced superconductivity in quasi-one-dimensional Ta2PdSe6\mathrm{Ta}_2 \mathrm{PdSe}_6, through a combination of electrical transport, synchrotron x-ray diffraction, and theoretical calculations. Our transport measurements show that the superconductivity appears at a critical pressure Pc∼18.3P_{\mathrm{c}} \sim 18.3 GPa and is robust upon further compression up to 62.662.6 GPa. The estimated upper critical field μ0Hc2(0)\mu_0 H_{\mathrm{c} 2}(0) in the pressurized Ta2PdSe6\mathrm{Ta}_2 \mathrm{PdSe}_6 is much lower than the Pauli limiting field, in contrast to the case in its isostructural analogs M2PdxX5M_2 \mathrm{Pd}_{\mathrm{x}} X_5 (M=Nb(M=\mathrm{Nb}, Ta; X=S,Se)X=\mathrm{S}, \mathrm{Se}). Concomitant with the occurrence of superconductivity, anomalies in pressuredependent transport properties are observed, including sign reversal of Hall coefficient, abnormally enhanced resistance, and dramatically suppressed magnetoresistance. Meanwhile, room-temperature synchrotron x-ray diffraction experiments reveal the stability of the pristine monoclinic structure (space group C2/mC 2 / m ) upon compression. Combined with the density functional theory calculations, we argue that a pressure-induced Lifshitz transition could be the electronic origin of the emergent superconductivity in Ta2PdSe6\mathrm{Ta}_2 \mathrm{PdSe}_6.Comment: 7 pages, 7 figure

    The potential mechanism of Aidi injection against neuroblastoma—an investigation based on network pharmacology analysis

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    Background: Aidi injection, a classic traditional Chinese medicine (TCM) formula, has been used on a broader scale in treating a variety of cancers. In this study, we aimed to explore the potential anti-tumor effects of Aidi injection in the treatment of neuroblastoma (NB) using network pharmacology (NP).Methods: To elucidate the anti-NB mechanism of Aidi injection, an NP-based approach and molecular docking validation were employed. The compounds and target genes were collected from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database and Bioinformatics Analysis Tool for Molecular mechANism of Traditional Chinese Medicine (BATMAN-TCM) database. The protein–protein interaction network was constructed using the STRING database. clusterProfiler (R package) was utilized to annotate the bioinformatics of hub target genes. The gene survival analysis was performed on R2, a web-based genomic analysis application. iGEMDOCK was used for molecular docking validation, and GROMACS was utilized to validate molecular docking results. Furthermore, we investigated the anticancer effects of gomisin B and ginsenoside Rh2 on human NB cells using a cell viability assay. The Western blot assay was used to validate the protein levels of target genes in gomisin B- and ginsenoside Rh2-treated NB cells.Results: A total of 2 critical compounds with 16 hub target genes were identified for treating NB. All 16 hub genes could potentially influence the survival of NB patients. The top three genes (EGFR, ESR1, and MAPK1) were considered the central hub genes from the drug–compound–hub target gene–pathway network. The endocrine resistance and estrogen signaling pathways were identified as the therapeutic pathways using the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Gomisin B and ginsenoside Rh2 showed a good binding ability to the target protein in molecular docking. The results of cell experiments showed the anti-NB effect of gomisin B and ginsenoside Rh2. In addition, the administration of gomisin B over-regulated the expression of ESR1 protein in MYCN-amplified NB cells.Conclusion: In the present study, we investigated the potential pharmacological mechanisms of Aidi against NB and revealed the anti-NB effect of gomisin B, providing clinical evidence of Aidi in treating NB and establishing baselines for further research
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