Excessive fusel alcohol contents will cause the beer to produce off-flavors and cause dizziness and headaches.Reducing the contents of fusel alcohols in beer is very important to people's health.The excessive fuse...Excessive fusel alcohol contents will cause the beer to produce off-flavors and cause dizziness and headaches.Reducing the contents of fusel alcohols in beer is very important to people's health.The excessive fusel alcohol contents in beer is a common problem in the industry.How to control the contents of fusel alcohols in a reasonable range is of great significance for improving beer quality.After one round of ultraviolet(UV)and one round of multifunctional plasma mutagenesis system(MPMS)mutagenesis,the yeast strains with lower fusel oil yield and more stablility could be screened.According to the relationship between the fusel alcohol Harris metabolic pathway of brewer's yeast and lactic acid metabolism,excellent strains were obtained by triple screening with lactic acid medium,calcium carbonate medium and 2,3,5-triphenyl tetrazolium chloride upper medium.The content of fusel alcohol in the finished beer fermentation test of screened strain Z43 was 52.1±0.142 mg•L^(-1),which was 43%lower than that of the starting strain,and other fermentation properties remained unchanged.After eight passages,it was verified that the strain was stable and heritable.These results showed that strain Z43 presented promising characteristics for use in the production of beer with a potentially low contents of fusel alcohols.展开更多
Geo-interfaces refer to the contact surfaces between multiple media within geological strata,as well as the transition zones that regulate the migration of three-phase matter,changes in physical states,and the deforma...Geo-interfaces refer to the contact surfaces between multiple media within geological strata,as well as the transition zones that regulate the migration of three-phase matter,changes in physical states,and the deformation and stability of rock and soil masses.Owing to the combined effects of natural factors and human activities,geo-interfaces play crucial roles in the emergence,propagation,and triggering of geological disasters.Over the past three decades,the material point method(MPM)has emerged as a preferred approach for addressing large deformation problems and simulating soil-water-structure interactions,making it an ideal tool for analyzing geo-interface behaviors.In this review,we offer a systematic summary of the basic concepts,classifications,and main characteristics of the geo-interface,and provide a comprehensive overview of recent advances and developments in simulating geo-interface using the MPM.We further present a brief description of various MPMs for modeling different types of geo-interfaces in geotechnical engineering applications and highlight the existing limitations and future research directions.This study aims to facilitate innovative applications of the MPM in modeling complex geo-interface problems,providing a reference for geotechnical practitioners and researchers.展开更多
随着山区高速公路建设的迅速推进,弃渣场的稳定性及潜在失稳灾害评估日益受到重视。具有巨大能量的滑坡体,可能会冲击破坏沿途的结构物进而威胁生命财产安全。充分发挥利用物质点法(material point method,MPM)可以对连续介质大变形过...随着山区高速公路建设的迅速推进,弃渣场的稳定性及潜在失稳灾害评估日益受到重视。具有巨大能量的滑坡体,可能会冲击破坏沿途的结构物进而威胁生命财产安全。充分发挥利用物质点法(material point method,MPM)可以对连续介质大变形过程模拟和离散元法(digital elevation model,DEM)能够精准的接触判断优势,MPM-DEM耦合算法可有效解决滑坡体与复杂地形、沿线结构物之间的相互作用问题。文章基于GPU并行高性能计算软件CoSim中的MPM-DEM耦合算法,实现了对弃渣场边坡稳定性、潜在失稳灾害的动力学分析。研究首先以散粒体冲击结构物的算例,验证了该算法的合理性与准确性;在此基础上,以云南某高速公路弃渣场为研究案例,进一步计算其稳定性系数,并预测潜在失稳灾害的影响范围与危害程度。结果表明,该弃渣场边坡目前处于稳定状态;若发生失稳,滑坡体将对下游高速公路桥桩产生巨大冲击力。该耦合算法在弃渣场边坡稳定性与失稳灾害动力学分析中具备显著优势,能够实现边坡“稳定性→大变形→流动→堆积”的全过程分析。展开更多
Ground anchor drilling is a promising technology for investigating the mechanical properties and environmental variability of lunar regolith in low-gravity environments,with minimal demands for reactive cutting.This s...Ground anchor drilling is a promising technology for investigating the mechanical properties and environmental variability of lunar regolith in low-gravity environments,with minimal demands for reactive cutting.This study explores the interaction behavior during ground anchor drilling of lunar regolith by employing a coupled approach that integrates the Material Point Method(MPM)and the ContinuouseDiscontinuous Element Method(CDEM),considering the interactions among numerous particles and blocks.The numerical parameters are calibrated based on experimental penetration resistance data of lunar regolith simulant.The numerical approach effectively captures key mechanical properties of the simulant,such as particle flow and scattering patterns,anchor penetration effects,and disturbance-related ultimate bearing characteristics.Additionally,this study examines the influence of inter-particle friction and compactness on penetration resistance.By combining the Golden Section Search Method(GSSM)with ground anchor drilling simulations,an inverse analysis model for penetration resistance is developed,allowing for the determination of mechanical parameters of the lunar regolith simulant.The feasibility of this parameter inversion method is verified,providing valuable insights for engineering applications in lunar exploration and construction.展开更多
In this study,a powerful thermo-hydro-mechanical(THM)coupling solution scheme for saturated poroelastic media involving brittle fracturing is developed.Under the local thermal non-equilibrium(LTNE)assumption,this sche...In this study,a powerful thermo-hydro-mechanical(THM)coupling solution scheme for saturated poroelastic media involving brittle fracturing is developed.Under the local thermal non-equilibrium(LTNE)assumption,this scheme seamlessly combines the material point method(MPM)for accurately tracking solid-phase deformation and heat transport,and the Eulerian finite element method(FEM)for effectively capturing fluid flow and heat advection-diffusion behavior.The proposed approach circumvents the substantial challenges posed by large nonlinear equation systems with the monolithic solution scheme.The staggered solution process strategically separates each physical field through explicit or implicit integration.The characteristic-based method is used to stabilize advection-dominated heat flows for efficient numerical implementation.Furthermore,a fractional step approach is employed to decompose fluid velocity and pressure,thereby suppressing pore pressure oscillation on the linear background grid.The fracturing initiation and propagation are simulated by a rate-dependent phase field model.Through a series of quasi-static and transient simulations,the exceptional performance and promising potential of the proposed model in addressing THM fracturing problems in poro-elastic media is demonstrated.展开更多
基金Supported by Heilongjiang Natural Science Foundation Joint Guide Project(LH2019C022)。
文摘Excessive fusel alcohol contents will cause the beer to produce off-flavors and cause dizziness and headaches.Reducing the contents of fusel alcohols in beer is very important to people's health.The excessive fusel alcohol contents in beer is a common problem in the industry.How to control the contents of fusel alcohols in a reasonable range is of great significance for improving beer quality.After one round of ultraviolet(UV)and one round of multifunctional plasma mutagenesis system(MPMS)mutagenesis,the yeast strains with lower fusel oil yield and more stablility could be screened.According to the relationship between the fusel alcohol Harris metabolic pathway of brewer's yeast and lactic acid metabolism,excellent strains were obtained by triple screening with lactic acid medium,calcium carbonate medium and 2,3,5-triphenyl tetrazolium chloride upper medium.The content of fusel alcohol in the finished beer fermentation test of screened strain Z43 was 52.1±0.142 mg•L^(-1),which was 43%lower than that of the starting strain,and other fermentation properties remained unchanged.After eight passages,it was verified that the strain was stable and heritable.These results showed that strain Z43 presented promising characteristics for use in the production of beer with a potentially low contents of fusel alcohols.
基金supported by the National Science Fund for Distinguished Young Scholars of China(Grant No.42225702)the National Natural Science Foundation of China(Grant Nos.42461160266 and 52379106).
文摘Geo-interfaces refer to the contact surfaces between multiple media within geological strata,as well as the transition zones that regulate the migration of three-phase matter,changes in physical states,and the deformation and stability of rock and soil masses.Owing to the combined effects of natural factors and human activities,geo-interfaces play crucial roles in the emergence,propagation,and triggering of geological disasters.Over the past three decades,the material point method(MPM)has emerged as a preferred approach for addressing large deformation problems and simulating soil-water-structure interactions,making it an ideal tool for analyzing geo-interface behaviors.In this review,we offer a systematic summary of the basic concepts,classifications,and main characteristics of the geo-interface,and provide a comprehensive overview of recent advances and developments in simulating geo-interface using the MPM.We further present a brief description of various MPMs for modeling different types of geo-interfaces in geotechnical engineering applications and highlight the existing limitations and future research directions.This study aims to facilitate innovative applications of the MPM in modeling complex geo-interface problems,providing a reference for geotechnical practitioners and researchers.
文摘随着山区高速公路建设的迅速推进,弃渣场的稳定性及潜在失稳灾害评估日益受到重视。具有巨大能量的滑坡体,可能会冲击破坏沿途的结构物进而威胁生命财产安全。充分发挥利用物质点法(material point method,MPM)可以对连续介质大变形过程模拟和离散元法(digital elevation model,DEM)能够精准的接触判断优势,MPM-DEM耦合算法可有效解决滑坡体与复杂地形、沿线结构物之间的相互作用问题。文章基于GPU并行高性能计算软件CoSim中的MPM-DEM耦合算法,实现了对弃渣场边坡稳定性、潜在失稳灾害的动力学分析。研究首先以散粒体冲击结构物的算例,验证了该算法的合理性与准确性;在此基础上,以云南某高速公路弃渣场为研究案例,进一步计算其稳定性系数,并预测潜在失稳灾害的影响范围与危害程度。结果表明,该弃渣场边坡目前处于稳定状态;若发生失稳,滑坡体将对下游高速公路桥桩产生巨大冲击力。该耦合算法在弃渣场边坡稳定性与失稳灾害动力学分析中具备显著优势,能够实现边坡“稳定性→大变形→流动→堆积”的全过程分析。
基金financial support from the National Natural Science Foundation of China(Grant Nos.52178324,12102059,and 12472207).
文摘Ground anchor drilling is a promising technology for investigating the mechanical properties and environmental variability of lunar regolith in low-gravity environments,with minimal demands for reactive cutting.This study explores the interaction behavior during ground anchor drilling of lunar regolith by employing a coupled approach that integrates the Material Point Method(MPM)and the ContinuouseDiscontinuous Element Method(CDEM),considering the interactions among numerous particles and blocks.The numerical parameters are calibrated based on experimental penetration resistance data of lunar regolith simulant.The numerical approach effectively captures key mechanical properties of the simulant,such as particle flow and scattering patterns,anchor penetration effects,and disturbance-related ultimate bearing characteristics.Additionally,this study examines the influence of inter-particle friction and compactness on penetration resistance.By combining the Golden Section Search Method(GSSM)with ground anchor drilling simulations,an inverse analysis model for penetration resistance is developed,allowing for the determination of mechanical parameters of the lunar regolith simulant.The feasibility of this parameter inversion method is verified,providing valuable insights for engineering applications in lunar exploration and construction.
基金supported by National Natural Science Foundation of China(Grant No.42377149)the Research Grants Council of Hong Kong(General Research Fund Project No.17202423).
文摘In this study,a powerful thermo-hydro-mechanical(THM)coupling solution scheme for saturated poroelastic media involving brittle fracturing is developed.Under the local thermal non-equilibrium(LTNE)assumption,this scheme seamlessly combines the material point method(MPM)for accurately tracking solid-phase deformation and heat transport,and the Eulerian finite element method(FEM)for effectively capturing fluid flow and heat advection-diffusion behavior.The proposed approach circumvents the substantial challenges posed by large nonlinear equation systems with the monolithic solution scheme.The staggered solution process strategically separates each physical field through explicit or implicit integration.The characteristic-based method is used to stabilize advection-dominated heat flows for efficient numerical implementation.Furthermore,a fractional step approach is employed to decompose fluid velocity and pressure,thereby suppressing pore pressure oscillation on the linear background grid.The fracturing initiation and propagation are simulated by a rate-dependent phase field model.Through a series of quasi-static and transient simulations,the exceptional performance and promising potential of the proposed model in addressing THM fracturing problems in poro-elastic media is demonstrated.
