本文研究了新型惯质调谐质量阻尼器(novel tuned mass damper inerter,NTMDI)的安装方法对其优化设计与减振性能的影响。详细介绍了NTMDI-R(反向安装的NTMDI)的力学模型,并采用经典固定点理论对NTMDI-R进行了优化设计,得到了NTMDI-R最...本文研究了新型惯质调谐质量阻尼器(novel tuned mass damper inerter,NTMDI)的安装方法对其优化设计与减振性能的影响。详细介绍了NTMDI-R(反向安装的NTMDI)的力学模型,并采用经典固定点理论对NTMDI-R进行了优化设计,得到了NTMDI-R最优结构参数的解析式;对比研究了NTMDI-R与现有四种经典调谐质量阻尼器(TMD、TMDI、VTMD和NTMDI)在简谐激励和随机激励下的减振效果,并探究了安装方法对NTMDI-R减振性能的影响。结果表明:正、反向安装的两种减振器(NTMDI和NTMDI-R)优化参数不同,安装方法对其减振性能有较大影响。当表观质量比β小于0.1时,NTMDI-R的减振效果差于NTMDI;而β大于0.1时,NTMDI-R的减振效果与NTMDI基本一致,因此采用NTMDI进行结构减振应明确其安装方向。基础加速度和荷载力分别作用下,NTMDI-R的减振效果相对于NTMDI分别降低了3.9%和4.7%。展开更多
目的 建立一测多评(quantitative analysis of multi-components by single marker, QAMS)法同时测定穿心莲中9种成分含量的分析方法。方法 采用超高效液相色谱-串联质谱法,以穿心莲内酯为内参物,建立该成分与连翘苷、齐墩果酸、咖啡酸...目的 建立一测多评(quantitative analysis of multi-components by single marker, QAMS)法同时测定穿心莲中9种成分含量的分析方法。方法 采用超高效液相色谱-串联质谱法,以穿心莲内酯为内参物,建立该成分与连翘苷、齐墩果酸、咖啡酸、穿心莲内酯、脱水穿心莲内酯、穿心莲新酯、去氧穿心莲内酯、脱水穿心莲内酯琥珀酸半酯、亚硫酸氢钠穿心莲内脂的相对校正因子,利用相对校正因子来计算各成分的含量,同时将QAMS法计算结果和外标法实测值进行比较。结果 相对校正因子重现性良好,使用QAMS法与外标法所测得的结果无明显的差异。结论 QAMS法适用于穿心莲中9种成分的同时测定,以保证质量的可靠性。展开更多
In this study, we introduce a system of differential equations describing the motion of a single point mass or of two interacting point masses on a surface, that is solved by a fourth-order explicit Runge–Kutta(RK4) ...In this study, we introduce a system of differential equations describing the motion of a single point mass or of two interacting point masses on a surface, that is solved by a fourth-order explicit Runge–Kutta(RK4) scheme. The forces acting on the masses are gravity, the reaction force of the surface, friction, and, in case of two masses, their mutual interaction force. This latter is introduced by imposing that the geometrical distance between the coupled masses is constant. The solution is computed under the assumption that the point masses strictly slide on the surface, without leaping or rolling. To avoid complications stemming from numerical errors related to real topographies that are only known over discrete grids, we restrict our attention to simulations on analytical continuous surfaces. This study sets the basis for a generalization to more complex systems of masses, such as chains or matrices of blocks that are often used to model complex processes such as landslides and rockfalls. The results shown in this paper provide a background for a companion paper in which the system of equations is generalized, and different geometries are presented.展开更多
文摘本文研究了新型惯质调谐质量阻尼器(novel tuned mass damper inerter,NTMDI)的安装方法对其优化设计与减振性能的影响。详细介绍了NTMDI-R(反向安装的NTMDI)的力学模型,并采用经典固定点理论对NTMDI-R进行了优化设计,得到了NTMDI-R最优结构参数的解析式;对比研究了NTMDI-R与现有四种经典调谐质量阻尼器(TMD、TMDI、VTMD和NTMDI)在简谐激励和随机激励下的减振效果,并探究了安装方法对NTMDI-R减振性能的影响。结果表明:正、反向安装的两种减振器(NTMDI和NTMDI-R)优化参数不同,安装方法对其减振性能有较大影响。当表观质量比β小于0.1时,NTMDI-R的减振效果差于NTMDI;而β大于0.1时,NTMDI-R的减振效果与NTMDI基本一致,因此采用NTMDI进行结构减振应明确其安装方向。基础加速度和荷载力分别作用下,NTMDI-R的减振效果相对于NTMDI分别降低了3.9%和4.7%。
文摘目的 建立一测多评(quantitative analysis of multi-components by single marker, QAMS)法同时测定穿心莲中9种成分含量的分析方法。方法 采用超高效液相色谱-串联质谱法,以穿心莲内酯为内参物,建立该成分与连翘苷、齐墩果酸、咖啡酸、穿心莲内酯、脱水穿心莲内酯、穿心莲新酯、去氧穿心莲内酯、脱水穿心莲内酯琥珀酸半酯、亚硫酸氢钠穿心莲内脂的相对校正因子,利用相对校正因子来计算各成分的含量,同时将QAMS法计算结果和外标法实测值进行比较。结果 相对校正因子重现性良好,使用QAMS法与外标法所测得的结果无明显的差异。结论 QAMS法适用于穿心莲中9种成分的同时测定,以保证质量的可靠性。
基金mostly financed by the FP7 Project ASTARTE "Assessment,Strategy and Risk Reduction for 740 Tsunamis in Europe"(FP7-ENV2013 6.4-3,Grant603839)the Italian National Project RITMARE that,among others,treat landslide models with tsunamigenic potential
文摘In this study, we introduce a system of differential equations describing the motion of a single point mass or of two interacting point masses on a surface, that is solved by a fourth-order explicit Runge–Kutta(RK4) scheme. The forces acting on the masses are gravity, the reaction force of the surface, friction, and, in case of two masses, their mutual interaction force. This latter is introduced by imposing that the geometrical distance between the coupled masses is constant. The solution is computed under the assumption that the point masses strictly slide on the surface, without leaping or rolling. To avoid complications stemming from numerical errors related to real topographies that are only known over discrete grids, we restrict our attention to simulations on analytical continuous surfaces. This study sets the basis for a generalization to more complex systems of masses, such as chains or matrices of blocks that are often used to model complex processes such as landslides and rockfalls. The results shown in this paper provide a background for a companion paper in which the system of equations is generalized, and different geometries are presented.
