该研究搭建流动管反应器研究了气态硫酸-水-氨气(H2SO4-H2O-NH3)三元成核体系,实测了不同NH3浓度条件下新粒子成核速率和生长速率与前驱气体浓度、温度和湿度各影响因素之间参数化关系。依据气溶胶动态平衡方程,结合实际大气成核过程中...该研究搭建流动管反应器研究了气态硫酸-水-氨气(H2SO4-H2O-NH3)三元成核体系,实测了不同NH3浓度条件下新粒子成核速率和生长速率与前驱气体浓度、温度和湿度各影响因素之间参数化关系。依据气溶胶动态平衡方程,结合实际大气成核过程中成核速率、碰并清除速率、生长速率和新粒子浓度变化速率的定量联系,间接估算出大气新粒子碰撞捕获效率系数γ在10 nm以下平均值为0.07,在10~20 nm平均值为0.12。结合Kerminen and Kulmala公式,将实测的参数化关系式耦合到区域空气质量模型WRF-Chem中,用模式模拟了2016年杭州G20会议期间新粒子生成粒径谱、纳米级气溶胶数浓度和亚微米气溶胶数浓度,结果表明能够在一定程度上预测新粒子生成事件的发生和超细粒子的数浓度。展开更多
An approach to feature-based parametric design for die and mould is proposed in this paper.The assembly relationship and parts of the die and mould are described by feature.The dependent relationship of features is de...An approach to feature-based parametric design for die and mould is proposed in this paper.The assembly relationship and parts of the die and mould are described by feature.The dependent relationship of features is described by parent-child operator structure.The feature shape and location can be modified by design parameters.An expert system is used for deriving a geometry of the features which satisfies the given constraints.This approach provides a more natural and convenient method of representing a parametric model of the die and mould.展开更多
In this paper, the concept of toric difference varieties is defined and four equivalent descriptions for toric difference varieties are presented in terms of difference rational parametrization,difference coordinate r...In this paper, the concept of toric difference varieties is defined and four equivalent descriptions for toric difference varieties are presented in terms of difference rational parametrization,difference coordinate rings, toric difference ideals, and group actions by difference tori. Connections between toric difference varieties and affine N[x]-semimodules are established by proving the one-to-one correspondence between irreducible invariant difference subvarieties and faces of N[x]-semimodules and the orbit-face correspondence. Finally, an algorithm is given to decide whether a binomial difference ideal represented by a Z[x]-lattice defines a toric difference variety.展开更多
文摘该研究搭建流动管反应器研究了气态硫酸-水-氨气(H2SO4-H2O-NH3)三元成核体系,实测了不同NH3浓度条件下新粒子成核速率和生长速率与前驱气体浓度、温度和湿度各影响因素之间参数化关系。依据气溶胶动态平衡方程,结合实际大气成核过程中成核速率、碰并清除速率、生长速率和新粒子浓度变化速率的定量联系,间接估算出大气新粒子碰撞捕获效率系数γ在10 nm以下平均值为0.07,在10~20 nm平均值为0.12。结合Kerminen and Kulmala公式,将实测的参数化关系式耦合到区域空气质量模型WRF-Chem中,用模式模拟了2016年杭州G20会议期间新粒子生成粒径谱、纳米级气溶胶数浓度和亚微米气溶胶数浓度,结果表明能够在一定程度上预测新粒子生成事件的发生和超细粒子的数浓度。
文摘An approach to feature-based parametric design for die and mould is proposed in this paper.The assembly relationship and parts of the die and mould are described by feature.The dependent relationship of features is described by parent-child operator structure.The feature shape and location can be modified by design parameters.An expert system is used for deriving a geometry of the features which satisfies the given constraints.This approach provides a more natural and convenient method of representing a parametric model of the die and mould.
基金supported by the National Natural Science Foundation of China under Grant No.11688101
文摘In this paper, the concept of toric difference varieties is defined and four equivalent descriptions for toric difference varieties are presented in terms of difference rational parametrization,difference coordinate rings, toric difference ideals, and group actions by difference tori. Connections between toric difference varieties and affine N[x]-semimodules are established by proving the one-to-one correspondence between irreducible invariant difference subvarieties and faces of N[x]-semimodules and the orbit-face correspondence. Finally, an algorithm is given to decide whether a binomial difference ideal represented by a Z[x]-lattice defines a toric difference variety.
