Annual trunk diameters and tree heights were measured in July after initial_girdling and regirdling in Eucommia ulmoides Oliv. And the percentages of fallen leaves in all leaves and burst buds in all buds were est...Annual trunk diameters and tree heights were measured in July after initial_girdling and regirdling in Eucommia ulmoides Oliv. And the percentages of fallen leaves in all leaves and burst buds in all buds were estimated respectively on every autumn or spring. The results indicated that although the tree growth slowed down in the first year after girdling, but in the second year after girdling, the growth of the girdled trees tended to become normalized and up to the third year, it was similar to that of the normal trees. According to its developmental trait after girdling, the authors suggested that optimal girdling of the trees is in every 4 or 5 year intervals. With this method it was able to improve bark production and to protect the resource from extinction as well.展开更多
The microstructural features of hypoeutectic AI-10%Si alloy were observed using optical microscopy and electron backscatter diffraction. The results show that primary silicon particles are frequently found in hypoeute...The microstructural features of hypoeutectic AI-10%Si alloy were observed using optical microscopy and electron backscatter diffraction. The results show that primary silicon particles are frequently found in hypoeutectic alloys. Hence, the nucleation and growth mechanisms of the precipitation of primary silicon of hypoeutectic Al-10%Si alloy melts were investigated. It was discovered that Si atoms are easy to segregate and form Si-Si clusters, which results in the formation of primary silicon even in eutectic or hypoeutectic Al-Si alloys. In addition, solute redistribution caused by chemical driving force and large pile-ups or micro-segregation of the solute play an important role in the formation of the primary silicon, and the solute redistribution equations were derived from Jackson-Chalmers equations. Once Si solute concentration exceeds eutectic composition, primary silicon precipitates are formed at the front of solid/liquid interface.展开更多
文摘Annual trunk diameters and tree heights were measured in July after initial_girdling and regirdling in Eucommia ulmoides Oliv. And the percentages of fallen leaves in all leaves and burst buds in all buds were estimated respectively on every autumn or spring. The results indicated that although the tree growth slowed down in the first year after girdling, but in the second year after girdling, the growth of the girdled trees tended to become normalized and up to the third year, it was similar to that of the normal trees. According to its developmental trait after girdling, the authors suggested that optimal girdling of the trees is in every 4 or 5 year intervals. With this method it was able to improve bark production and to protect the resource from extinction as well.
基金Project (U1134101) supported by the Mutual Foundation of Basic Research of High Speed Railway,ChinaProjects (ZR2009FL003,ZR2010EL011,ZR2011EMM003) supported by the Natural Science Foundation of Shandong Province,China
文摘The microstructural features of hypoeutectic AI-10%Si alloy were observed using optical microscopy and electron backscatter diffraction. The results show that primary silicon particles are frequently found in hypoeutectic alloys. Hence, the nucleation and growth mechanisms of the precipitation of primary silicon of hypoeutectic Al-10%Si alloy melts were investigated. It was discovered that Si atoms are easy to segregate and form Si-Si clusters, which results in the formation of primary silicon even in eutectic or hypoeutectic Al-Si alloys. In addition, solute redistribution caused by chemical driving force and large pile-ups or micro-segregation of the solute play an important role in the formation of the primary silicon, and the solute redistribution equations were derived from Jackson-Chalmers equations. Once Si solute concentration exceeds eutectic composition, primary silicon precipitates are formed at the front of solid/liquid interface.
