The harmonic analyses of monthly mean total ozone in the atmosphere over the Northern Hemisphere for 26 years (1960-1985) are made by using the Fourier expansion. The analysed results show that there is obviously a qu...The harmonic analyses of monthly mean total ozone in the atmosphere over the Northern Hemisphere for 26 years (1960-1985) are made by using the Fourier expansion. The analysed results show that there is obviously a quasi-biennial oscillation (QBO) in the interannual variations of the amplitudes of total ozone. Generally, the amplitudes of wavenumber 1 and 2 during the westerly of the equatorial QBO are larger than those during the easterly. In the early winter, the amplitude of wavenumber 1 during the easterly phase is larger, and in the late winter, it is larger during the westerly phase. These are in good agreement with the observational distributions.展开更多
Bi-modulus materials with different mechanical responses in tension and compression are often found in civil,composite, and biological engineering. Numerical analysis of bimodular materials is strongly nonlinear and c...Bi-modulus materials with different mechanical responses in tension and compression are often found in civil,composite, and biological engineering. Numerical analysis of bimodular materials is strongly nonlinear and convergence is usually a problem for traditional iterative schemes. This paper aims to develop a stabilized computational method for nonlinear analysis of 3D bimodular materials. Based on the parametric variational principle, a unified constitutive equation of 3D bimodular materials is proposed, which allows the eight principal stress states to be indicated by three parametric variables introduced in the principal stress directions.The original problem is transformed into a standard linear complementarity problem（LCP） by the parametric virtual work principle and a quadratic programming algorithm is developed by solving the LCP with the classic Lemke＇s algorithm. Update of elasticity and stiffness matrices is avoided and, thus, the proposed algorithm shows an excellent convergence behavior compared with traditional iterative schemes.Numerical examples show that the proposed method is valid and can accurately analyze mechanical responses of 3D bimodular materials. Also, stability of the algorithm is greatly improved.展开更多
Further geometric morphometric analysis of the genus Eysarcoris was done based on the former studies to classified the nine Eysarcoris species from China. In this study, six characters, such as forewing, hindwing, pyg...Further geometric morphometric analysis of the genus Eysarcoris was done based on the former studies to classified the nine Eysarcoris species from China. In this study, six characters, such as forewing, hindwing, pygophore, head, pronotum and scutellum, were selected to investigate the shape variation of Eysarcoris. Significant divergence in the shapes of the six characters was observed among the species（p 〈 0.05）. For all methods, phenetic similarity based on the six characters agrees with the current status of the genus. The cluster analysis of eight species are consistent with the traditional morphological studies. CVA analysis also shows that the values of the six characters are not equal in taxonomy. Pygophore, forewing, hindwing and pronotum play more important roles in the classification.展开更多
文摘The harmonic analyses of monthly mean total ozone in the atmosphere over the Northern Hemisphere for 26 years (1960-1985) are made by using the Fourier expansion. The analysed results show that there is obviously a quasi-biennial oscillation (QBO) in the interannual variations of the amplitudes of total ozone. Generally, the amplitudes of wavenumber 1 and 2 during the westerly of the equatorial QBO are larger than those during the easterly. In the early winter, the amplitude of wavenumber 1 during the easterly phase is larger, and in the late winter, it is larger during the westerly phase. These are in good agreement with the observational distributions.
基金supported by the National Natural Science Foundation of China (Grants 11232003, 91315302, 11502035)the Open Research Foundation (Grant GZ1404) of State Key Laboratory of Structural Analysis for Industrial Equipment at Dalian University of Technology
文摘Bi-modulus materials with different mechanical responses in tension and compression are often found in civil,composite, and biological engineering. Numerical analysis of bimodular materials is strongly nonlinear and convergence is usually a problem for traditional iterative schemes. This paper aims to develop a stabilized computational method for nonlinear analysis of 3D bimodular materials. Based on the parametric variational principle, a unified constitutive equation of 3D bimodular materials is proposed, which allows the eight principal stress states to be indicated by three parametric variables introduced in the principal stress directions.The original problem is transformed into a standard linear complementarity problem（LCP） by the parametric virtual work principle and a quadratic programming algorithm is developed by solving the LCP with the classic Lemke＇s algorithm. Update of elasticity and stiffness matrices is avoided and, thus, the proposed algorithm shows an excellent convergence behavior compared with traditional iterative schemes.Numerical examples show that the proposed method is valid and can accurately analyze mechanical responses of 3D bimodular materials. Also, stability of the algorithm is greatly improved.
基金benefited from the National Natural Sciences Foundation of China(31440078,31501840)Shanxi Province Programs for Science and Technology Development(20150311010-7)+1 种基金Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(2017169)Graduate Innovation Project in Shanxi Province(2016BY067)
文摘Further geometric morphometric analysis of the genus Eysarcoris was done based on the former studies to classified the nine Eysarcoris species from China. In this study, six characters, such as forewing, hindwing, pygophore, head, pronotum and scutellum, were selected to investigate the shape variation of Eysarcoris. Significant divergence in the shapes of the six characters was observed among the species（p 〈 0.05）. For all methods, phenetic similarity based on the six characters agrees with the current status of the genus. The cluster analysis of eight species are consistent with the traditional morphological studies. CVA analysis also shows that the values of the six characters are not equal in taxonomy. Pygophore, forewing, hindwing and pronotum play more important roles in the classification.
