13 research outputs found

    Effect of Trichoderma viride on rhizosphere microbial communities and biocontrol of soybean root rot

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    Biological seed dressing is a cost-effective means to protect plant roots from pathogens. Trichoderma is generally considered as one of the most common biological seed dressings. However, there is still a dearth of information on the effects of Trichoderma on microbial community of rhizosphere soil. High-throughput sequencing was used to analyze the effects of Trichoderma viride and a chemical fungicide on microbial community of soybean rhizosphere soil. The results showed that both T. viride and chemical fungicide could significantly reduce the disease index of soybean (15.11% for Trichoderma and 17.33% for Chemical), while no significant difference was observed between them. Both T. viride and chemical fungicide could affect the structure of rhizosphere microbial community, they increased the β-diversity of microbial community and significantly reduce the relative abundance of Saprotroph-Symbiotroph. Chemical fungicide could reduce the complexity and stability of co-occurrence network. However, T. viride is beneficial for maintaining network stability and increasing network complexity. There were 31 bacterial genera and 21 fungal genera significantly correlated with the disease index. Furthermore, several potential plant pathogenic microorganisms were also positively correlated with disease index, such as Fusarium, Aspergillus, Conocybe, Naganishia, and Monocillium. From this work, T. viride may be used as a substitute for chemical fungicide to control soybean root rot and be more friendly to soil microecology

    Selective Ethylene Glycol Oxidation to Formate on Nickel Selenide with Simultaneous Evolution of Hydrogen

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    There is an urgent need for cost-effective strategies to produce hydrogen from renewable net-zero carbon sources using renewable energies. In this context, the electrochemical hydrogen evolution reaction can be boosted by replacing the oxygen evolution reaction with the oxidation of small organic molecules, such as ethylene glycol (EG). EG is a particularly interesting organic liquid with two hydroxyl groups that can be transformed into a variety of C1 and C2 chemicals, depending on the catalyst and reaction conditions. Here, a catalyst is demonstrated for the selective EG oxidation reaction (EGOR) to formate on nickel selenide. The catalyst nanoparticle (NP) morphology and crystallographic phase are tuned to maximize its performance. The optimized NiS electrocatalyst requires just 1.395 V to drive a current density of 50 mA cm −2 in 1 potassium hydroxide (KOH) and 1 EG. A combination of in situ electrochemical infrared absorption spectroscopy (IRAS) to monitor the electrocatalytic process and ex situ analysis of the electrolyte composition shows the main EGOR product is formate, with a Faradaic efficiency above 80%. Additionally, C2 chemicals such as glycolate and oxalate are detected and quantified as minor products. Density functional theory (DFT) calculations of the reaction process show the glycol-to-oxalate pathway to be favored via the glycolate formation, where the C-C bond is broken and further electro-oxidized to formate. A combination of in situ and ex situ analysis shows the main product of the ethylene glycol (EG) oxidation reaction (EGOR) is formate with a Faradaic efficiency above 80%, and glycolate and oxalate as minor chemicals on nickel selenide nanoparticles (NPs). Further density functional theory (DFT) calculation reveals the electrooxidation mechanism to these products

    FgCsn12 Is Involved in the Regulation of Ascosporogenesis in the Wheat Scab Fungus Fusarium graminearum

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    Fusarium head blight (FHB), caused by the fungal pathogen Fusarium graminearum, is a destructive disease worldwide. Ascospores are the primary inoculum of F. graminearum, and sexual reproduction is a critical step in its infection cycle. In this study, we characterized the functions of FgCsn12. Although the ortholog of FgCsn12 in budding yeast was reported to have a direct interaction with Csn5, which served as the core subunit of the COP9 signalosome, the interaction between FgCsn12 and FgCsn5 was not detected through the yeast two-hybrid assay. The deletion of FgCSN12 resulted in slight defects in the growth rate, conidial morphology, and pathogenicity. Instead of forming four-celled, uninucleate ascospores, the Fgcsn12 deletion mutant produced oval ascospores with only one or two cells and was significantly defective in ascospore discharge. The 3′UTR of FgCsn12 was dispensable for vegetative growth but essential for sexual reproductive functions. Compared with those of the wild type, 1204 genes and 2240 genes were up- and downregulated over twofold, respectively, in the Fgcsn12 mutant. Taken together, FgCsn12 demonstrated an important function in the regulation of ascosporogenesis in F. graminearum

    Microwave-Assisted Synthesis of MoS<sub>2</sub>/BiVO<sub>4</sub> Heterojunction for Photocatalytic Degradation of Tetracycline Hydrochloride

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    Compared with traditional hydrothermal synthesis, microwave-assisted synthesis has the advantages of being faster and more energy efficient. In this work, the MoS2/BiVO4 heterojunction photocatalyst was synthesized by the microwave-assisted hydrothermal method within 30 min. The morphology, structure and chemical composition were characterized by X-ray diffraction (XRD), Raman, X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and high-resolution transmission electron microscopy (HRTEM). The results of characterizations demonstrated that the synthesized MoS2/BiVO4 heterojunction was a spherical structure with dimensions in the nanorange. In addition, the photocatalytic activity of the samples was investigated by degrading tetracycline hydrochloride (TC) under visible light irradiation. Results indicated that the MoS2/BiVO4 heterojunction significantly improved the photocatalytic performance compared with BiVO4 and MoS2, in which the degradation rate of TC (5 mg L−1) by compound where the mass ratio of MoS2/BiVO4 was 5 wt% (MB5) was 93.7% in 90 min, which was 2.36 times of BiVO4. The active species capture experiments indicated that •OH, •O2− and h+ active species play a major role in the degradation of TC. The degradation mechanism and pathway of the photocatalysts were proposed through the analysis of the band structure and element valence state. Therefore, microwave technology provided a quick and efficient way to prepare MoS2/BiVO4 heterojunction photocatalytic efficiently

    Vehicle Stability Analysis under Extreme Operating Conditions Based on LQR Control

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    Under extreme working conditions such as high-speed driving on roads with a large road surface unevenness coefficient, turning on a road with a low road surface adhesion coefficient, and emergency acceleration and braking, a vehicle’s stability deteriorates sharply and reduces ride comfort. There is extensive existing research on vehicle active suspension control, trajectory tracking, and control methods. However, most of these studies focus on conventional operating conditions, while vehicle stability analysis under extreme operating conditions is much less studied. In order to improve the stability of the whole vehicle under extreme operating conditions, this paper investigates the stability of a vehicle under extreme operating conditions based on linear quadratic regulator (LQR) control. First, a seven degrees of freedom (7-DOF) dynamics model of the whole vehicle is established based on the use of electromagnetic active suspension, and then an LQR controller of the electromagnetic active suspension is designed. A joint simulation platform incorporating MATLAB and CarSim was built, and the CarSim model is verified by real vehicle tests. Finally, the stability of the vehicle under four different ultimate operating conditions was analyzed. The simulation results show that the root mean square (RMS) values of body droop acceleration and pitch angle acceleration are improved by 57.48% and 28.81%, respectively, under high-speed driving conditions on Class C roads. Under the double-shift condition with a low adhesion coefficient, the RMS values of body droop acceleration, pitch acceleration, and roll angle acceleration are improved by 58.25%, 55.41%, and 31.39%, respectively. These results indicate that electromagnetic active suspension can significantly improve vehicle stability and reduce driving risk under extreme working conditions when combined with an LQR controller

    Cobalt molybdenum nitride-based nanosheets for seawater splitting

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    Altres ajuts: ICN2 is funded by the CERCA Programme/Generalitat de Catalunya. Part of the present work has been performed in the framework of Universitat Autònoma de Barcelona Materials Science PhD program.The development of cost-effective bifunctional catalysts for water electrolysis is both a crucial necessity and an exciting scientific challenge. Herein, a simple approach based on a metal-organic framework sacrificial template to preparing cobalt molybdenum nitride supported on nitrogen-doped carbon nanosheets is reported. The porous structure of produced composite enables fast reaction kinetics, enhanced stability, and high corrosion resistance in critical seawater conditions. The cobalt molybdenum nitride-based electrocatalyst is tested toward both oxygen evolution reaction and hydrogen evolution reaction half-reactions using the seawater electrolyte, providing excellent performances that are rationalized using density functional theory. Subsequently, the nitride composite is tested as a bifunctional catalyst for the overall splitting of KOH-treated seawater from the Mediterranean Sea. The assembled system requires overpotentials of just 1.70 V to achieve a current density of 100 mA cm-2 in 1 M KOH seawater and continuously works for over 62 h. This work demonstrates the potential of transition-metal nitrides for seawater splitting and represents a step forward toward the cost-effective implementation of this technology

    Nanostructured Li<sub>2</sub>S Cathodes for Silicon–Sulfur Batteries

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    Lithium–sulfur batteries are regarded as an advantageous option for meeting the growing demand for high-energy-density storage, but their commercialization relies on solving the current limitations of both sulfur cathodes and lithium metal anodes. In this scenario, the implementation of lithium sulfide (Li2S) cathodes compatible with alternative anode materials such as silicon has the potential to alleviate the safety concerns associated with lithium metal. In this direction, here, we report a sulfur cathode based on Li2S nanocrystals grown on a catalytic host consisting of CoFeP nanoparticles supported on tubular carbon nitride. Nanosized Li2S is incorporated into the host by a scalable liquid infiltration–evaporation method. Theoretical calculations and experimental results demonstrate that the CoFeP–CN composite can boost the polysulfide adsorption/conversion reaction kinetics and strongly reduce the initial overpotential activation barrier by stretching the Li–S bonds of Li2S. Besides, the ultrasmall size of the Li2S particles in the Li2S–CoFeP–CN composite cathode facilitates the initial activation. Overall, the Li2S–CoFeP–CN electrodes exhibit a low activation barrier of 2.56 V, a high initial capacity of 991 mA h gLi2S–1, and outstanding cyclability with a small fading rate of 0.029% per cycle over 800 cycles. Moreover, Si/Li2S full cells are assembled using the nanostructured Li2S–CoFeP–CN cathode and a prelithiated anode based on graphite-supported silicon nanowires. These Si/Li2S cells demonstrate high initial discharge capacities above 900 mA h gLi2S–1 and good cyclability with a capacity fading rate of 0.28% per cycle over 150 cycles

    Phosphorous incorporation into palladium tin nanoparticles for the electrocatalytic formate oxidation reaction

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    The deployment of direct formate fuel cells (DFFCs) relies on the development of active and stable catalysts for the formate oxidation reaction (FOR). Palladium, providing effective full oxidation of formate to CO2, has been widely used as FOR catalyst, but it suffers from low stability, moderate activity, and high cost. Herein, we detail a colloidal synthesis route for the incorporation of P on Pd2Sn nanoparticles. These nanoparticles are dispersed on carbon black and the obtained composite is used as electrocatalytic material for the FOR. The Pd2Sn0.8P-based electrodes present outstanding catalytic activities with record mass current densities up to 10.0 A mgPd-1, well above those of Pd1.6Sn/C reference electrode. These high current densities are further enhanced by increasing the temperature from 25 °C to 40 °C. The Pd2Sn0.8P electrode also allows for slowing down the rapid current decay that generally happens during operation and can be rapidly re-activated through potential cycling. The excellent catalytic performance obtained is rationalized using density functional theory (DFT) calculations

    Sulfate-Decorated Amorphous-Crystalline Cobalt-Iron Oxide Nanosheets to Enhance O-O Coupling in the Oxygen Evolution Reaction

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    The electrochemical oxygen evolution reaction (OER) plays a fundamental role in several energy technologies, which performance and cost-effectiveness are in large part related to the used OER electrocatalyst. Herein, we detail the synthesis of cobalt-iron oxide nanosheets containing controlled amounts of well-anchored SO42- anionic groups (CoFexOy-SO4). We use a cobalt-based zeolitic imidazolate framework (ZIF-67) as the structural template and a cobalt source and Mohr's salt ((NH4)2Fe(SO4)2·6H2O) as the source of iron and sulfate. When combining the ZIF-67 with ammonium iron sulfate, the protons produced by the ammonium ion hydrolysis (NH4+ + H2O = NH3·H2O + H+) etch the ZIF-67, dissociating its polyhedron structure, and form porous assemblies of two-dimensional nanostructures through a diffusion-controlled process. At the same time, iron ions partially replace cobalt within the structure, and SO42- ions are anchored on the material surface by exchange with organic ligands. As a result, ultrathin CoFexOy-SO4 nanosheets are obtained. The proposed synthetic procedure enables controlling the amount of Fe and SO4 ions and analyzing the effect of each element on the electrocatalytic activity. The optimized CoFexOy-SO4 material displays outstanding OER activity with a 10 mA cm-2 overpotential of 268 mV, a Tafel slope of 46.5 mV dec-1, and excellent stability during 62 h. This excellent performance is correlated to the material's structural and chemical parameters. The assembled nanosheet structure is characterized by a large electrochemically active surface area, a high density of reaction sites, and fast electron transportation. Meanwhile, the introduction of iron increases the electrical conductivity of the catalysts and provides fast reaction sites with optimum bond energy and spin state for the adsorption of OER intermediates. The presence of sulfate ions at the catalyst surface modifies the electronic energy level of active sites, regulates the adsorption of intermediates to reduce the OER overpotential, and promotes the surface charge transfer, which accelerates the formation of oxygenated intermediates. Overall, the present work details the synthesis of a high-efficiency OER electrocatalyst and demonstrates the introduction of nonmetallic anionic groups as an excellent strategy to promote electrocatalytic activity in energy conversion technologies.The authors thank the support from the projects Combenergy (PID2019-105490RB-C32) from the Spanish Ministerio de Ciencia e Innovación, ENE2016-77798-C4-3-R and NANOGEN (PID2020-116093RB-C43), funded by MCIN/AEI/10.13039/501100011033/ and by “ERDF A way of making Europe”, by the “European Union”. The authors also thank the Spanish Ministry of Science and Innovation through the Severo Ochoa (CEX2019-000917-S) and OXISOT (PID2021- 128410OB-I00) projects. X.W., X.H., C.X., and R.D. thank the China Scholarship Council (CSC) for the scholarship support. The authors acknowledge funding from Generalitat de Catalunya 2017 SGR 327 and 2017 SGR 1246. ICN2 is supported by the Severo Ochoa program from Spanish MCIN / AEI (Grant No.: CEX2021-001214-S). IREC and ICN2 are funded by the CERCA Programme/Generalitat de Catalunya. Z.L. acknowledges funding from MINECO SO-FPT Ph.D. grant (SEV-2013-0295-17-1). J.L. is a Serra Húnter Fellow and is grateful to MICINN/FEDER PID2021-124572OB-C31, GC 2017 SGR 128 and ICREA Academia program. Part of the present work has been performed in the frameworks of Universitat de Barcelona Nanoscience Ph.D. program and Universitat Autònoma de Barcelona Materials Science Ph.D. program.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

    Cobalt Molybdenum Nitride-Based Nanosheets for Seawater Splitting

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    The development of cost-effective bifunctional catalysts for water electrolysis is both a crucial necessity and an exciting scientific challenge. Herein, a simple approach based on a metal–organic framework sacrificial template to preparing cobalt molybdenum nitride supported on nitrogen-doped carbon nanosheets is reported. The porous structure of produced composite enables fast reaction kinetics, enhanced stability, and high corrosion resistance in critical seawater conditions. The cobalt molybdenum nitride-based electrocatalyst is tested toward both oxygen evolution reaction and hydrogen evolution reaction half-reactions using the seawater electrolyte, providing excellent performances that are rationalized using density functional theory. Subsequently, the nitride composite is tested as a bifunctional catalyst for the overall splitting of KOH-treated seawater from the Mediterranean Sea. The assembled system requires overpotentials of just 1.70 V to achieve a current density of 100 mA cm–2 in 1 M KOH seawater and continuously works for over 62 h. This work demonstrates the potential of transition-metal nitrides for seawater splitting and represents a step forward toward the cost-effective implementation of this technology
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