在线维修是节约核电厂大修工期和提升经济性的重要手段。然而目前EPR核电厂运行技术规范(Operating Technical Specifications,OTS)对乏燃料水池冷却和处理系统(Fuel pool cooling and purification system,PTR)的管理要求限制了PTR及...在线维修是节约核电厂大修工期和提升经济性的重要手段。然而目前EPR核电厂运行技术规范(Operating Technical Specifications,OTS)对乏燃料水池冷却和处理系统(Fuel pool cooling and purification system,PTR)的管理要求限制了PTR及其相关系统在线维修的效率和灵活性。OTS对PTR系统的管理要求来自乏燃料水池(Spent Fuel Pool,SFP)相关设计基准事故(Design Basis Condition,DBC),这些事故采用基于“乏燃料水池温度”的验收准则,事故后需要PTR系统尽快投入运行防止SFP沸腾。为了提高PTR系统在线维修灵活性,本文根据乏燃料水池事故特点,结合国内法规和同类型核电厂的良好实践,将SFP相关DBC事故的验收准则修改为基于“乏燃料组件淹没”的验收准则并重新开展事故分析。根据新的事故分析结果,优化反应堆功率运行期间PTR系统的最低可用列数要求,为PTR系统在线维修的优化提供依据。展开更多
为了完成进化动力反应堆(Evolutionary Power Reactor,EPR)压力容器单体顶盖的水压密封试验,设计一套专用的水压密封工装。介绍该工装的设计要求、结构特性和材料选用,并应用ABAQUS软件对关键部件在水压工况下的应力进行校核计算。实际...为了完成进化动力反应堆(Evolutionary Power Reactor,EPR)压力容器单体顶盖的水压密封试验,设计一套专用的水压密封工装。介绍该工装的设计要求、结构特性和材料选用,并应用ABAQUS软件对关键部件在水压工况下的应力进行校核计算。实际应用结果表明,该密封工装的性能能够满足水压试验设计要求。展开更多
Liquid-liquid phase separation(LLPS)of proteins and nucleic acids is a common phenomenon in cells that underlies the formation of membraneless organelles.Although the macroscopic behavior of biomolecular coacervates h...Liquid-liquid phase separation(LLPS)of proteins and nucleic acids is a common phenomenon in cells that underlies the formation of membraneless organelles.Although the macroscopic behavior of biomolecular coacervates has been elucidated by microscopy,the detailed dynamic properties of proteins/peptides during the LLPS process remain poorly characterized.Here,site-directed spin labeling-electron paramagnetic resonance(SDSL-EPR)spectroscopy was employed to characterize the dynamic properties of a minimal model LLPS system consisting of positively charged peptides and RNA.The degree of phase separation,indicated by broadening of the EPR spectrum of the spin-labeled peptide due to slow molecular tumbling,was monitored by EPR.In addition,three distinct populations with varying molecular motion during LLPS,featuring different spectral lineshapes,were identified.These populations included a fast motion component(Ⅰ),a slower motion component(Ⅱ)associated with peptides in the dispersed phase and an immobile component(Ⅲ)observed in the dense phase.With gradual titration of the peptides to RNA,the EPR spectrum gradually shifted,refiecting changes in the populations of the components.Together,SDSL-EPR method not only provides new insights into the dynamic behavior of biomolecules during LLPS,but also offers a sensitive method for biomolecular phase separation processes at the molecular level.展开更多
文摘为了完成进化动力反应堆(Evolutionary Power Reactor,EPR)压力容器单体顶盖的水压密封试验,设计一套专用的水压密封工装。介绍该工装的设计要求、结构特性和材料选用,并应用ABAQUS软件对关键部件在水压工况下的应力进行校核计算。实际应用结果表明,该密封工装的性能能够满足水压试验设计要求。
基金supported by the National Natural Science Foundation of China(No.21927814)the National Key Research and Development Program of China(Nos.2019YFA0405600,2019YFA0706900,2021YFA1200104,2022YFC3400500)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(Nos.XDB0540200,XDB37040201)Plans for Major Provincial Science&Technology Projects(No.202303a07020004)the Youth Innovation Promotion Association,CAS(No.2022455)。
文摘Liquid-liquid phase separation(LLPS)of proteins and nucleic acids is a common phenomenon in cells that underlies the formation of membraneless organelles.Although the macroscopic behavior of biomolecular coacervates has been elucidated by microscopy,the detailed dynamic properties of proteins/peptides during the LLPS process remain poorly characterized.Here,site-directed spin labeling-electron paramagnetic resonance(SDSL-EPR)spectroscopy was employed to characterize the dynamic properties of a minimal model LLPS system consisting of positively charged peptides and RNA.The degree of phase separation,indicated by broadening of the EPR spectrum of the spin-labeled peptide due to slow molecular tumbling,was monitored by EPR.In addition,three distinct populations with varying molecular motion during LLPS,featuring different spectral lineshapes,were identified.These populations included a fast motion component(Ⅰ),a slower motion component(Ⅱ)associated with peptides in the dispersed phase and an immobile component(Ⅲ)observed in the dense phase.With gradual titration of the peptides to RNA,the EPR spectrum gradually shifted,refiecting changes in the populations of the components.Together,SDSL-EPR method not only provides new insights into the dynamic behavior of biomolecules during LLPS,but also offers a sensitive method for biomolecular phase separation processes at the molecular level.
