提出了一种计算无界声媒质空间中任意形状辐射体辐射声场的新方法——综合Helmholtz积分公式法(Synthetic Helmholtz Integral Equation Formulation,SHIEF)。该方法将关于辐射体的内部、表面和外部Helmholtz积分方程有机地组合在一起,...提出了一种计算无界声媒质空间中任意形状辐射体辐射声场的新方法——综合Helmholtz积分公式法(Synthetic Helmholtz Integral Equation Formulation,SHIEF)。该方法将关于辐射体的内部、表面和外部Helmholtz积分方程有机地组合在一起,在已知辐射体表面法向振速的条件下,求出辐射体表面的声压分布,进而求其辐射声场分布。运用该方法计算分析了脉动球相对辐射阻抗随相对半径的变化情况,通过与理论值以及已有的其他方法(例如联立Helmholtz积分公式法(CHIEF)、超定外部Helmholtz积分公式法等)的比较,证明了该方法的正确性、准确性以及快速性,该方法有效地克服了CHIEF法和超定外部Helmholtz积分公式法的缺点。展开更多
The combined selection index used in the breeding of new Yorkshire dam line with high prolificacy according to breeding objects was formulated as /:2.272E- BVNB-0.056EBVDAYS. After 5 generations breeding, the two mai...The combined selection index used in the breeding of new Yorkshire dam line with high prolificacy according to breeding objects was formulated as /:2.272E- BVNB-0.056EBVDAYS. After 5 generations breeding, the two main selected traits such as total number of born and age at 100 kg weight was 12.17 piglets/litter and 165.18 d, respectively. The genetic improvements per generates was 0.156 and -2.198, respec- tively. The breeding objects of the new Yorkshire dam line with high prolificacy were basically reached. It indicated that the methods and index could be used in pig breeding.展开更多
文摘提出了一种计算无界声媒质空间中任意形状辐射体辐射声场的新方法——综合Helmholtz积分公式法(Synthetic Helmholtz Integral Equation Formulation,SHIEF)。该方法将关于辐射体的内部、表面和外部Helmholtz积分方程有机地组合在一起,在已知辐射体表面法向振速的条件下,求出辐射体表面的声压分布,进而求其辐射声场分布。运用该方法计算分析了脉动球相对辐射阻抗随相对半径的变化情况,通过与理论值以及已有的其他方法(例如联立Helmholtz积分公式法(CHIEF)、超定外部Helmholtz积分公式法等)的比较,证明了该方法的正确性、准确性以及快速性,该方法有效地克服了CHIEF法和超定外部Helmholtz积分公式法的缺点。
基金Supported by National Science and Technology Support Plan during the Eleventh Five-year Plan(2006BAD01A08-02)Hubei Agricultural Innovation Program(2007-620-004-003)Special Fund for Modern Pig Production Technology Construction(NYCYTX-009)~~
文摘The combined selection index used in the breeding of new Yorkshire dam line with high prolificacy according to breeding objects was formulated as /:2.272E- BVNB-0.056EBVDAYS. After 5 generations breeding, the two main selected traits such as total number of born and age at 100 kg weight was 12.17 piglets/litter and 165.18 d, respectively. The genetic improvements per generates was 0.156 and -2.198, respec- tively. The breeding objects of the new Yorkshire dam line with high prolificacy were basically reached. It indicated that the methods and index could be used in pig breeding.