The cooperation effects of GA3, IAA and uniconazole-P were studied on the gravitropism and wood formation in Fraxinus mandshurica Rupr. var.japonica Maxim. Seedlings using traditional paraffin section technology. Our ...The cooperation effects of GA3, IAA and uniconazole-P were studied on the gravitropism and wood formation in Fraxinus mandshurica Rupr. var.japonica Maxim. Seedlings using traditional paraffin section technology. Our results are: (1) Gravitropism of stems was strongly inhibited only in B, whereas promoted significantly in D, E, F, H and I treatments; (2) Xylem formation was increased on both sides in H, I and J treatments and on the lower side in E and F which also show the synergistic effect; (3) On the radial direction, cell wall thickness was enhanced on the upper side, whereas decreased on the lower side in C, and was also significantly promoted on the upper in E, G, H, I and J treatments. On the tangential direction, cell wall thickness was increased on the lower side in E, H, I and J treatments respectively; (4) Gelatinous layer of wood fibers was observed on the upper side in all treatments. These results suggest that both GA3 and IAA affected negative gravitropism and wood formation significantly. However, appliedor unapplited-uniconazole-P does not affect G-layer formation, indicating GA does not play the key role on G-layer formation, and ratio of GA3/IAA or IAA may be more important in regulating G-layer formation.展开更多
In this paper,the effects of forward speed on the lateral vibration of a slender structure in an infinite fluid are considered.By equating the bending stress of the structure with the hydrodynamic force acting on it,t...In this paper,the effects of forward speed on the lateral vibration of a slender structure in an infinite fluid are considered.By equating the bending stress of the structure with the hydrodynamic force acting on it,the equation which governs the fluid-structure interaction of a slender structure both vibrating and moving in water is obtained.Numerical results show that the influence of forward speed on the vibration of a slender structure in water is significant.It behaves like damping,reducing both natural frequencies and responses significantly.展开更多
基金This research was supported by the scholarship from the Japanese Ministry of Education (No. 07456073), Scientific Research Foundation for the Returned Oversea Chinese Scholars, State Education Ministry of China, Natural Science Foundation of Tianjin, China (No. 07JCYBJCI2400 and No. 07JCYBJCI2500) and National Key Basic Research Plan Proiect (No. 2007CB 106802).
文摘The cooperation effects of GA3, IAA and uniconazole-P were studied on the gravitropism and wood formation in Fraxinus mandshurica Rupr. var.japonica Maxim. Seedlings using traditional paraffin section technology. Our results are: (1) Gravitropism of stems was strongly inhibited only in B, whereas promoted significantly in D, E, F, H and I treatments; (2) Xylem formation was increased on both sides in H, I and J treatments and on the lower side in E and F which also show the synergistic effect; (3) On the radial direction, cell wall thickness was enhanced on the upper side, whereas decreased on the lower side in C, and was also significantly promoted on the upper in E, G, H, I and J treatments. On the tangential direction, cell wall thickness was increased on the lower side in E, H, I and J treatments respectively; (4) Gelatinous layer of wood fibers was observed on the upper side in all treatments. These results suggest that both GA3 and IAA affected negative gravitropism and wood formation significantly. However, appliedor unapplited-uniconazole-P does not affect G-layer formation, indicating GA does not play the key role on G-layer formation, and ratio of GA3/IAA or IAA may be more important in regulating G-layer formation.
基金Supported by the National Natural Science Foundation of China under Grant No.50921001"973" Project under Grant No.2010CB832700
文摘In this paper,the effects of forward speed on the lateral vibration of a slender structure in an infinite fluid are considered.By equating the bending stress of the structure with the hydrodynamic force acting on it,the equation which governs the fluid-structure interaction of a slender structure both vibrating and moving in water is obtained.Numerical results show that the influence of forward speed on the vibration of a slender structure in water is significant.It behaves like damping,reducing both natural frequencies and responses significantly.