载荷装备通过软土地面会引起了软土地面的变形,车轮侵入软土的深度是软土地面装备通行性评估的重要参数。本文提出了连续-非连续单元法(Continuum-discontinuum Element Method,CDEM)与物质点法(Material Point Meth⁃od,MPM)耦合的数值...载荷装备通过软土地面会引起了软土地面的变形,车轮侵入软土的深度是软土地面装备通行性评估的重要参数。本文提出了连续-非连续单元法(Continuum-discontinuum Element Method,CDEM)与物质点法(Material Point Meth⁃od,MPM)耦合的数值计算方法,建立了车轮-软土地面耦合模型,模拟了车轮和软土地面相互作用过程,定量分析车轮载重、软土弹性模量、软土强度参数(黏聚力、摩擦角)与软土表面压应力、侵入深度等参数之间的关系,获得车轮侵入软土深度的变化规律。研究表明:软土侵入深度与车轮载重接近线性正相关,相对改变量约为179%;与弹性模量非线性负相关,相对改变量约为23%;与强度参数非线性负相关,相对改变量约为164%。当车轮载重一定时,非线性变化的车轮侵入深度对软土强度参数更敏感。建立强度参数(黏聚力、摩擦角)和侵入深度变化的三维关系,可为软土地面装备通行性评估中现场待测的关键参数提供理论依据。展开更多
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
针对制造企业工时定额信息化管理需求,提出基于标准工序体系的工时定额快速、准确核定方法。通过建立标准工序库,梳理影响标准工序工时测算的生产特征与生产因素,提炼影响工时核算的时间因子;根据作业人员、作业工具及作业环境等因素对...针对制造企业工时定额信息化管理需求,提出基于标准工序体系的工时定额快速、准确核定方法。通过建立标准工序库,梳理影响标准工序工时测算的生产特征与生产因素,提炼影响工时核算的时间因子;根据作业人员、作业工具及作业环境等因素对工时的影响,制定宽放系数;结合标准工时定额核算经验,形成工时定额计算公式。并基于制造过程管理(Manufacturing Process Management,MPM)系统,开发了工时核定模块,实现了工时快速、准确、实时核定及其与下游MES端生产信息的无缝衔接,为工时核算、计划排产提供了依据。展开更多
文摘载荷装备通过软土地面会引起了软土地面的变形,车轮侵入软土的深度是软土地面装备通行性评估的重要参数。本文提出了连续-非连续单元法(Continuum-discontinuum Element Method,CDEM)与物质点法(Material Point Meth⁃od,MPM)耦合的数值计算方法,建立了车轮-软土地面耦合模型,模拟了车轮和软土地面相互作用过程,定量分析车轮载重、软土弹性模量、软土强度参数(黏聚力、摩擦角)与软土表面压应力、侵入深度等参数之间的关系,获得车轮侵入软土深度的变化规律。研究表明:软土侵入深度与车轮载重接近线性正相关,相对改变量约为179%;与弹性模量非线性负相关,相对改变量约为23%;与强度参数非线性负相关,相对改变量约为164%。当车轮载重一定时,非线性变化的车轮侵入深度对软土强度参数更敏感。建立强度参数(黏聚力、摩擦角)和侵入深度变化的三维关系,可为软土地面装备通行性评估中现场待测的关键参数提供理论依据。
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.
文摘针对制造企业工时定额信息化管理需求,提出基于标准工序体系的工时定额快速、准确核定方法。通过建立标准工序库,梳理影响标准工序工时测算的生产特征与生产因素,提炼影响工时核算的时间因子;根据作业人员、作业工具及作业环境等因素对工时的影响,制定宽放系数;结合标准工时定额核算经验,形成工时定额计算公式。并基于制造过程管理(Manufacturing Process Management,MPM)系统,开发了工时核定模块,实现了工时快速、准确、实时核定及其与下游MES端生产信息的无缝衔接,为工时核算、计划排产提供了依据。
