An idea to develop a family of cellular cores for sandwich panels using a technology of prepreg folding is presented. Polar folded quadra structures are regarded as a geometric basis for these cores whose standard fra...An idea to develop a family of cellular cores for sandwich panels using a technology of prepreg folding is presented. Polar folded quadra structures are regarded as a geometric basis for these cores whose standard frag ment has lhe fourlh degree of axial symmelry. The classification of the polar strucluresaredeseribedanda method of various quadra slrueture synthesis is developed. A possibilily to provide high strength of lhe structure due m preservation of faces reinforcement pattern is presented. Arrangemen! of the plane core on a bi curvature surface is also introduced. Besides, provision of isotropyof the core in two or three directions are described. Finally, exam ples of cellular folded cores manufaclured from basalt reinforced plaslic are demonslrated.展开更多
<正> A detailed study of the formation of toroidal condensation produced from the 2700 base pair fragments of plasmid PUCI3 DNA, induced by metal ions, is introduced. We have extracted several typical intermedia...<正> A detailed study of the formation of toroidal condensation produced from the 2700 base pair fragments of plasmid PUCI3 DNA, induced by metal ions, is introduced. We have extracted several typical intermediate structures based on investigation by electron microscopy, and compared their size distributions. The observations suggest that the formation process of DNA condensation is the process of folding and arranging DNA chains and that of disorderorder transition. The result also indicates that the condensed particles are polymeric, but not randomly aggregative, further proving thetoroidal structures are formed in certain regularities.展开更多
基金supported by the Ministry of Education and Science of Russian Federation (No.RFMEFI57414X0078)
文摘An idea to develop a family of cellular cores for sandwich panels using a technology of prepreg folding is presented. Polar folded quadra structures are regarded as a geometric basis for these cores whose standard frag ment has lhe fourlh degree of axial symmelry. The classification of the polar strucluresaredeseribedanda method of various quadra slrueture synthesis is developed. A possibilily to provide high strength of lhe structure due m preservation of faces reinforcement pattern is presented. Arrangemen! of the plane core on a bi curvature surface is also introduced. Besides, provision of isotropyof the core in two or three directions are described. Finally, exam ples of cellular folded cores manufaclured from basalt reinforced plaslic are demonslrated.
基金Project supported by the National Natural Science Foundation of China and the National Education Committee of China
文摘<正> A detailed study of the formation of toroidal condensation produced from the 2700 base pair fragments of plasmid PUCI3 DNA, induced by metal ions, is introduced. We have extracted several typical intermediate structures based on investigation by electron microscopy, and compared their size distributions. The observations suggest that the formation process of DNA condensation is the process of folding and arranging DNA chains and that of disorderorder transition. The result also indicates that the condensed particles are polymeric, but not randomly aggregative, further proving thetoroidal structures are formed in certain regularities.
