A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDO...A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more homogeneously.Besides,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress mitigation.This paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.展开更多
Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite(Ag-Zeo-HAp) coatin...Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite(Ag-Zeo-HAp) coating was synthesized on Ti O_2-coated Mg alloy by physical vapour deposition(PVD) assisted electrodeposition technique to decrease the degradation rate of Mg alloy. X-ray diffraction(XRD) analysis and field emission scanning electron microscopy(FE-SEM) images showed the formation of a uniform and compact layer of Ag-Zeo-HAp with a thickness of 15 μm on the Ti O_2 film with a thickness of 1 μm. The potentiodynamic polarization(PDP) and electrochemical impedance spectroscopy(EIS) tests indicated that corrosion resistance of Mg-Ca alloy was considerably increased by the Ag-Zeo-HAp coating. The bioactivity test in the simulated body fluid(SBF) solution showed that a dense and homogeneous bonelike apatite layer was formed on the Ag-Zeo-HAp surface after 14 d. Investigation of antibacterial activity via disk diffusion and spread plate methods showed that the Ag-Zeo-HAp coating had a significantly larger inhibition zone(3.86 mm) towards Escherichia coli(E. coli) compared with the Ti O_2-coated Mg alloy(2.61 mm). The Ag-Zeo-HAp coating showed high antibacterial performance, good bioactivity, and high corrosion resistance which make it a perfect coating material for biomedical applications.镁基合金作为临时植入材料的应用受到了越来越多的关注,然而,由于其降解速率高,因此应用受到了限制。为了降低镁合金的降解速率,本文作者采用物理气相沉积(PVD)辅助电沉积技术在镀氧化钛(Ti O_2)的镁合金上涂覆掺银-沸石羟基磷灰石(Ag-Zeo-HAp)涂层。X射线衍射(XRD)分析和场发射扫描电镜(FESEM)图片显示,在厚度约为1μm的二氧化钛薄膜上形成了均匀且致密的Ag-Zeo-HAp涂层,厚度约为15μm。动电位极化(PDP)和电化学阻抗谱(EIS)测试表明,通过Ag-Zeo-HAp涂层,Mg-Ca合金的耐腐蚀性大大提高。模拟体液(SBF)浸泡测试生物活性试验结果表明,在14 d后的Ag-Zeo-HAp表面上形成了一层致密且均匀的类骨磷灰石层。采用琼脂扩散法和平板涂布法对抗菌活性进行研究。结果表明,与Ti O_2涂层的镁合金(2.61 mm)相比,Ag-Zeo-HAp涂层对大肠杆菌(E.coli)的抑制区(3.86 mm)明显增大。Ag-Zeo-HAp涂层具有良好的抗菌性能、良好的生物活性和耐腐蚀性,是生物医学应用的理想涂层材料。展开更多
Four wheat (Triticum aestivum L.) cultivars 711, PBW343, 3765 and WH542 were screened for studying variations in glycinebetaine (GB) content and plant dry mass under 100 mmol L-1 NaCl stress. A tolerance index was cal...Four wheat (Triticum aestivum L.) cultivars 711, PBW343, 3765 and WH542 were screened for studying variations in glycinebetaine (GB) content and plant dry mass under 100 mmol L-1 NaCl stress. A tolerance index was calculated using plant dry mass data to select salt-tolerant and salt-sensitive types and find association between tolerance index and GB content. Tolerance index has been used as a good criterion to select the tolerant types under high salinity stress. Further, physiological differences in salt-tolerant cultivar 711 and salt-sensitive cultivar WH542 were examined. The salt-tolerant cultivar exhibited greater GB content, which was found correlative with ethylene. The cultivar also showed higher nitrogen (N) content and nitrate reductase activity, reduced glutathione and higher redox state resulting in maximal protection of plant dry mass than the salt-sensitive type. Thus, the content of GB may be considered as important physiological criteria for selecting salt-tolerant wheat types.展开更多
基金the National Research Foundation of Korea(Nos.2018R1A5A7023490 and 2022R1A2C1003003)。
文摘A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyCo_(z)O_(2)(x≥0.8)(NMC)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMC particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more homogeneously.Besides,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress mitigation.This paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMC active particles mitigates stress levels.
文摘Mg-based alloys received significant attention for temporary implant applications while, their applications have been limited by high degradation rate. Therefore, silver-zeolite doped hydroxyapatite(Ag-Zeo-HAp) coating was synthesized on Ti O_2-coated Mg alloy by physical vapour deposition(PVD) assisted electrodeposition technique to decrease the degradation rate of Mg alloy. X-ray diffraction(XRD) analysis and field emission scanning electron microscopy(FE-SEM) images showed the formation of a uniform and compact layer of Ag-Zeo-HAp with a thickness of 15 μm on the Ti O_2 film with a thickness of 1 μm. The potentiodynamic polarization(PDP) and electrochemical impedance spectroscopy(EIS) tests indicated that corrosion resistance of Mg-Ca alloy was considerably increased by the Ag-Zeo-HAp coating. The bioactivity test in the simulated body fluid(SBF) solution showed that a dense and homogeneous bonelike apatite layer was formed on the Ag-Zeo-HAp surface after 14 d. Investigation of antibacterial activity via disk diffusion and spread plate methods showed that the Ag-Zeo-HAp coating had a significantly larger inhibition zone(3.86 mm) towards Escherichia coli(E. coli) compared with the Ti O_2-coated Mg alloy(2.61 mm). The Ag-Zeo-HAp coating showed high antibacterial performance, good bioactivity, and high corrosion resistance which make it a perfect coating material for biomedical applications.镁基合金作为临时植入材料的应用受到了越来越多的关注,然而,由于其降解速率高,因此应用受到了限制。为了降低镁合金的降解速率,本文作者采用物理气相沉积(PVD)辅助电沉积技术在镀氧化钛(Ti O_2)的镁合金上涂覆掺银-沸石羟基磷灰石(Ag-Zeo-HAp)涂层。X射线衍射(XRD)分析和场发射扫描电镜(FESEM)图片显示,在厚度约为1μm的二氧化钛薄膜上形成了均匀且致密的Ag-Zeo-HAp涂层,厚度约为15μm。动电位极化(PDP)和电化学阻抗谱(EIS)测试表明,通过Ag-Zeo-HAp涂层,Mg-Ca合金的耐腐蚀性大大提高。模拟体液(SBF)浸泡测试生物活性试验结果表明,在14 d后的Ag-Zeo-HAp表面上形成了一层致密且均匀的类骨磷灰石层。采用琼脂扩散法和平板涂布法对抗菌活性进行研究。结果表明,与Ti O_2涂层的镁合金(2.61 mm)相比,Ag-Zeo-HAp涂层对大肠杆菌(E.coli)的抑制区(3.86 mm)明显增大。Ag-Zeo-HAp涂层具有良好的抗菌性能、良好的生物活性和耐腐蚀性,是生物医学应用的理想涂层材料。
文摘Four wheat (Triticum aestivum L.) cultivars 711, PBW343, 3765 and WH542 were screened for studying variations in glycinebetaine (GB) content and plant dry mass under 100 mmol L-1 NaCl stress. A tolerance index was calculated using plant dry mass data to select salt-tolerant and salt-sensitive types and find association between tolerance index and GB content. Tolerance index has been used as a good criterion to select the tolerant types under high salinity stress. Further, physiological differences in salt-tolerant cultivar 711 and salt-sensitive cultivar WH542 were examined. The salt-tolerant cultivar exhibited greater GB content, which was found correlative with ethylene. The cultivar also showed higher nitrogen (N) content and nitrate reductase activity, reduced glutathione and higher redox state resulting in maximal protection of plant dry mass than the salt-sensitive type. Thus, the content of GB may be considered as important physiological criteria for selecting salt-tolerant wheat types.
