The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-c...The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped. Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.展开更多
The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy density.However,the high solubility of inte...The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy density.However,the high solubility of intermediate products(i.e.,lithium polysulfides)and the resultant shuttle effect lead to rapidly fading capacity and a low coulombic efficiency,which hinder the practical application of Li-S batteries.In this study,block copolymers are constructed with both an ethylene oxide unit and a styrene unit and then used as binders for Li-S batteries.Electrochemical performance improvements are attributed to the synergistic effects contributed by the different units of the block copolymer.The ethylene oxide unit traps polysulfide,which bonds strongly with the intermediate lithium polysulfide,and enhances the transport of lithium ions to reach high capacity.Meanwhile,the styrene unit maintains cathode integrity by improving the mechanical properties and elasticity of the constructed block copolymer to accommodate the large volume changes.By enabling multiple functions via different units in the polymer chain,high sulfur utilization is achieved,polysulfide diffusion is confined,and the shuttle effect is suppressed during the cycle life of Li-S batteries,as revealed by operando ultraviolet-visible spectroscopy and S Kedge X-ray absorption spectroscopy.展开更多
Since severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)-specific T cells have been found to play essential roles in host immune protection and pathology in patients with coronavirus disease 2019(COVID-19),th...Since severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)-specific T cells have been found to play essential roles in host immune protection and pathology in patients with coronavirus disease 2019(COVID-19),this study focused on the functional validation of T cell epitopes and the development of vaccines that induce specific T cell responses.A total of 120 CD8^(+)T cell epitopes from the E,M,N,S,and RdRp proteins were functionally validated.Among these,110,15,6,14,and 12 epitopes were highly homologous with SARS-CoV,OC43,NL63,HKU1,and 229E,respectively;in addition,four epitopes from the S protein displayed one amino acid that was distinct from the current SARS-CoV-2 variants.Then,31 epitopes restricted by the HLA-A2 molecule were used to generate peptide cocktail vaccines in combination with Poly(I:C),R848 or poly(lactic-co-glycolic acid)nanoparticles,and these vaccines elicited robust and specific CD8^(+)T cell responses in HLA-A2/DR1 transgenic mice as well as wild-type mice.In contrast to previous research,this study established a modified DC-peptide-PBL cell coculture system using healthy donor PBMCs to validate the in silico predicted epitopes,provided an epitope library restricted by nine of the most prevalent HLA-A allotypes covering broad Asian populations,and identified the HLA-A restrictions of these validated epitopes using competitive peptide binding experiments with HMy2.CIR cell lines expressing the indicated HLA-A allotype,which initially confirmed the in vivo feasibility of 9-or 10-mer peptide cocktail vaccines against SARS-CoV-2.These data will facilitate the design and development of vaccines that induce antiviral CD8^(+)T cell responses in COVID-19 patients.展开更多
基金National "863" project (NO.2001AA332030) of China
文摘The super high strength aluminum alloy ingots with 100 mm in diameter were cast by the process of low-frequency electromagnetic horizontal continuous casting (LFEHC) and the effect of electromagnetic field on the as-cast microstructure was studied. Results show that microstructure of the sample prepared by the LFEHC process was greatly refined. Microstructures at the border and the center of the ingots were fine, uniform and rosette-shaped. Electromagnetic frequency plays a key role in microstructure refining. Fine and uniform microstructures can be obtained with optimal electromagnetic frequency. In this experiment, under a frequency of 30 Hz the microstructure was the finest and the most uniform.
基金supported by the Assistant Secretary for Energy Efficiency and Renewable Energy,Vehicle Technologies Office,under the Advanced Battery Materials Research(BMR)Program of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231support by the U.S.Department of Energy under Contract No.106298-001+2 种基金the funding from Polish Ministry of Science and Higher Education No.1670/MOB/V/2017/0funding support of SUSTechthe resources of the National Energy Research Scientific Computing Center(NERSC)that is supported by the Office of Science of the U.S.Department of Energy。
文摘The lithium-sulfur(Li-S)battery is one of the most promising substitutes for current energy storage systems because of its low cost,high theoretical capacity,and high energy density.However,the high solubility of intermediate products(i.e.,lithium polysulfides)and the resultant shuttle effect lead to rapidly fading capacity and a low coulombic efficiency,which hinder the practical application of Li-S batteries.In this study,block copolymers are constructed with both an ethylene oxide unit and a styrene unit and then used as binders for Li-S batteries.Electrochemical performance improvements are attributed to the synergistic effects contributed by the different units of the block copolymer.The ethylene oxide unit traps polysulfide,which bonds strongly with the intermediate lithium polysulfide,and enhances the transport of lithium ions to reach high capacity.Meanwhile,the styrene unit maintains cathode integrity by improving the mechanical properties and elasticity of the constructed block copolymer to accommodate the large volume changes.By enabling multiple functions via different units in the polymer chain,high sulfur utilization is achieved,polysulfide diffusion is confined,and the shuttle effect is suppressed during the cycle life of Li-S batteries,as revealed by operando ultraviolet-visible spectroscopy and S Kedge X-ray absorption spectroscopy.
基金This work was supported by the National Nature Science Foundation of China(82041006)the COVID-19 Emergency Research Fund of Zhejiang University of China(2020XGZX021).
文摘Since severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)-specific T cells have been found to play essential roles in host immune protection and pathology in patients with coronavirus disease 2019(COVID-19),this study focused on the functional validation of T cell epitopes and the development of vaccines that induce specific T cell responses.A total of 120 CD8^(+)T cell epitopes from the E,M,N,S,and RdRp proteins were functionally validated.Among these,110,15,6,14,and 12 epitopes were highly homologous with SARS-CoV,OC43,NL63,HKU1,and 229E,respectively;in addition,four epitopes from the S protein displayed one amino acid that was distinct from the current SARS-CoV-2 variants.Then,31 epitopes restricted by the HLA-A2 molecule were used to generate peptide cocktail vaccines in combination with Poly(I:C),R848 or poly(lactic-co-glycolic acid)nanoparticles,and these vaccines elicited robust and specific CD8^(+)T cell responses in HLA-A2/DR1 transgenic mice as well as wild-type mice.In contrast to previous research,this study established a modified DC-peptide-PBL cell coculture system using healthy donor PBMCs to validate the in silico predicted epitopes,provided an epitope library restricted by nine of the most prevalent HLA-A allotypes covering broad Asian populations,and identified the HLA-A restrictions of these validated epitopes using competitive peptide binding experiments with HMy2.CIR cell lines expressing the indicated HLA-A allotype,which initially confirmed the in vivo feasibility of 9-or 10-mer peptide cocktail vaccines against SARS-CoV-2.These data will facilitate the design and development of vaccines that induce antiviral CD8^(+)T cell responses in COVID-19 patients.
