40 research outputs found

    Research on the Training Mechanism of Top-Notch Innovative Talents Based on Interdisciplinary

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    The construction of interdisciplinary top-notch innovative talent training mechanism is conducive to the cultivation of high-level interdisciplinary talents in my country, especially after the establishment of interdisciplinary categories, it puts forward new requirements for the integration of interdisciplinary development and talent training in universities. On the basis of the existing research, this paper puts forward the construction of five aspects of the training mechanism of interdisciplinary graduate student enrollment mechanism, interdisciplinary tutor allocation mechanism, interdisciplinary course setting mechanism, interdisciplinary expert organization and interdisciplinary quality assurance mechanism, in order to provide a certain basis for standardizing the cultivation of interdisciplinary top-notch innovative talents

    Highly efficient and stable p-type ZnO nanowires with piezotronic effect for photoelectrochemical water splitting

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    Unremitting efforts have been made to develop high-performance photoelectrochemical (PEC) water-splitting system to produce clean hydrogen fuel using sunlight. In this work, a novel way, combining highly-ordered nanowires (NWs) structure and piezotronic effect of p-type ZnO has been demonstrated to dramatically enhance PEC hydrogen evolution performance. Systematic characterizations indicate that the Sb atoms uniformly dope into ZnO NWs and substitute Zn sites with the introduction of two zinc vacancies to form the shallow acceptor SbZn–2VZn complex. Detailed synchrotron-based X-ray absorption near-edge structure (XANES) experiments in O K-edge and Zn L-edge further confirm the formation of the complex, and theoretical calculation verifies the Sb5+ state dominating the complex. The optimal photocurrent density of the 0.2Sb/ZnO-anneal NWs can reach −0.85 mA/cm2 (0 VRHE) which is 17.2 times larger than that of the n-ZnO NWs under sunlight illumination (100 mW/cm2). Furthermore, the piezotronic effect can be introduced to regulate the charge separation and transfer in the ZnO NWs through modulating the band structure near the interface. The photocurrent density can further increase to −1.08 mA/cm2 (0 VRHE) under a 0.6% tensile strain, which is 27.4% enhancement with respect to the ZnO sample without strain. These results provide an efficient way to design and develop high-performance photoelectrodes toward PEC hydrogen evolution

    Thyroid Disruption by Di-n-Butyl Phthalate (DBP) and Mono-n-Butyl Phthalate (MBP) in Xenopus laevis

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    BACKGROUND: Di-n-butyl phthalate (DBP), a chemical widely used in many consumer products, is estrogenic and capable of producing seriously reproductive and developmental effects in laboratory animals. However, recent in vitro studies have shown that DBP and mono-n-butyl phthalate (MBP), the major metabolite of DBP, possessed thyroid hormone receptor (TR) antagonist activity. It is therefore important to consider DBP and MBP that may interfere with thyroid hormone system. METHODOLOGY/PRINCIPAL FINDINGS: Nieuwkoop and Faber stage 51 Xenopus laevis were exposed to DBP and MBP (2, 10 or 15 mg/L) separately for 21 days. The two test chemicals decelerated spontaneous metamorphosis in X. laevis at concentrations of 10 and 15 mg/L. Moreover, MBP seemed to possess stronger activity. The effects of DBP and MBP on inducing changes of expression of selected thyroid hormone response genes: thyroid hormone receptor-beta (TRβ), retinoid X receptor gamma (RXRγ), alpha and beta subunits of thyroid-stimulating hormone (TSHα and TSHβ) were detected by qPCR at all concentrations of the compounds. Using mammalian two-hybrid assay in vitro, we found that DBP and MBP enhanced the interactions between co-repressor SMRT (silencing mediator for retinoid and thyroid hormone receptors) and TR in a dose-dependent manner, and MBP displayed more markedly. In addition, MBP at low concentrations (2 and 10 mg/L) caused aberrant methylation of TRβ in head tissue. CONCLUSIONS: The current findings highlight potential disruption of thyroid signalling by DBP and MBP and provide data for human risk assessment

    Vegetation Landscape Changes and Driving Factors of Typical Karst Region in the Anthropocene

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    Vegetation degeneration has become a serious ecological problem for karst regions in the Anthropocene. According to the deficiency of long serial and high-resolution analysis of karst vegetation, this paper reconstructed the variation of vegetation landscape changes from 1987 to 2020 in a typical karst region of China. Using Landsat time series data, the dynamic changes and driving factors of natural karst vegetation were identified at the landscape scale. On the premise of considering the time-lag effect, the main climatic factors that influence vegetation growth were presented at the interannual timescale. Then, the approach of residual analysis was adopted to distinguish the dominant factors affecting vegetation growth. Results of trend analysis revealed that 21.5% of the forestland showed an overall significant decline in vegetation growth, while only 1.5% showed an increase in vegetation growth during the study period. Precipitation and radiation were the dominant meteorological factors influencing vegetation at the interannual timescale, as opposed to temperature. More than 70% of the natural vegetation growth was dominated by climatic factors. The area percentage of negative human impact has increased gradually since 2009 and reached 18.5% in 2020, indicating the currently serious situation of vegetation protection; fortunately, in recent years, human disturbances on vegetation have been mitigated in karst areas with the promotion of ecological conservation and restoration projects

    Ni‐Carbon Microtube/Polytetrafluoroethylene as Flexible Electrothermal Microwave Absorbers

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    Abstract Flexible microwave absorbers with Joule heating performance are urgently desired to meet the demands of extreme service environments. Herein, a type of flexible composite film is constructed by homogeneously dispersing a hierarchical Ni‐carbon microtube (Ni/CMT) into a processable polytetrafluoroethylene (PTFE) matrix. The Ni/CMT are interconnected into a 3D conductive network, in which the huge interior cavity of the carbon microtube (CMT) improves impedance matching and provides additional hyper channels for electromagnetic (EM) waves dissipation, and the hierarchical magnetic Ni nanoparticles enhance the synergistic interactions between confined heterogeneous interfaces. Such an ingenious structure endows the composites with excellent electrothermal performance and improves their serviceability for application under extreme environments. Moreover, under a low fill loading of 3 wt.%, the Ni/CMT/PTFE (NCP) can achieve excellent low‐frequency microwave absorption (MA) property with a minimum reflection loss of −59.12 dB at 5.92 GHz, which covers almost the entire C‐band. Relying on their brilliant MA property, an EM sensor is designed and achieved by the resonance coupling of the patterned NCP. This work opens up a new way for the design of next‐generation microwave absorbers that meet the requirements of EM packaging, proofing water and removing ice, fire safety, and health monitoring

    Highly efficient and stable p-type ZnO nanowires with piezotronic effect for photoelectrochemical water splitting

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    Unremitting efforts have been made to develop high-performance photoelectrochemical (PEC) water-splitting system to produce clean hydrogen fuel using sunlight. In this work, a novel way, combining highly-ordered nanowires (NWs) structure and piezotronic effect of p-type ZnO has been demonstrated to dramatically enhance PEC hydrogen evolution performance. Systematic characterizations indicate that the Sb atoms uniformly dope into ZnO NWs and substitute Zn sites with the introduction of two zinc vacancies to form the shallow acceptor SbZn–2VZn complex. Detailed synchrotron-based X-ray absorption near-edge structure (XANES) experiments in O K-edge and Zn L-edge further confirm the formation of the complex, and theoretical calculation verifies the Sb5+ state dominating the complex. The optimal photocurrent density of the 0.2Sb/ZnO-anneal NWs can reach −0.85 mA/cm2 (0 VRHE) which is 17.2 times larger than that of the n-ZnO NWs under sunlight illumination (100 mW/cm2). Furthermore, the piezotronic effect can be introduced to regulate the charge separation and transfer in the ZnO NWs through modulating the band structure near the interface. The photocurrent density can further increase to −1.08 mA/cm2 (0 VRHE) under a 0.6% tensile strain, which is 27.4% enhancement with respect to the ZnO sample without strain. These results provide an efficient way to design and develop high-performance photoelectrodes toward PEC hydrogen evolution.</p

    Synthesis of Porous CoFe2O4 and Its Application as a Peroxidase Mimetic for Colorimetric Detection of H2O2 and Organic Pollutant Degradation

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    Porous CoFe2O4 was prepared via a simple and controllable method to develop a low-cost, high-efficiency, and good-stability nanozyme. The morphology and microstructure of the obtained CoFe2O4 was investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), specific surface area and pore analysis, and Raman spectroscopy. The results show that the annealing temperature has an important effect on the crystallinity, grain size, and specific surface area of CoFe2O4. CoFe2O4 obtained at 300 &deg;C (CF300) exhibits the largest surface area (up to 204.1 m2 g&minus;1) and the smallest grain size. The peroxidase-like activity of CoFe2O4 was further verified based on the oxidation of peroxidase substrate 3,3&rsquo;,5,5&rsquo;-tetramethylbenzidine (TMB) in the presence of H2O2. The best peroxidase-like activity for CF300 should be ascribed to its largest surface area and smallest grain size. On this basis, an effective method of colorimetric detection H2O2 was established. In addition, the porous CoFe2O4 was also used for the catalytic oxidation of methylene blue (MB), indicating potential applications in pollutant removal and water treatment
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