A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liqu...A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse transformation.The effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies.The physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman spectroscopy.The results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing temperature.Furthermore,a model is established to ex-plain the unique induction effect of C_(60) in the transformation process.This work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch.展开更多
Since neodymium magnet possesses an extremely strong magnetic field, resulting from the combination of neodymium, iron and boron, it has become the most used in designing autonomous sumo robots. When it is mounted und...Since neodymium magnet possesses an extremely strong magnetic field, resulting from the combination of neodymium, iron and boron, it has become the most used in designing autonomous sumo robots. When it is mounted under the structure of this robot, the magnet produces a large amount of normal force resulting from the interaction between its field lines and the steel frame of the arena, reducing the risk of slipping its wheels. Thus, the heavier a robot, the greater the difficulty for the opponent to remove it from the arena. This article explains the properties of Nd-Fe-Br magnets and analyzes the influence of these characteristics in the relation induction/weight. Additionally, to a comparative analysis, this research analyzes the positioning, geometry and polarization of the magnets under study, based on numerical results obtained using Inventor and K ＆ J Magnets Calculator software, given that these factors influence in their energetic product generation. Furthermore, more than just working with what we believe is a subject of great interest for sumo robot＇s teams, this study encourages their competitiveness, an essential factor for the competition.展开更多
文摘A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse transformation.The effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies.The physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman spectroscopy.The results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing temperature.Furthermore,a model is established to ex-plain the unique induction effect of C_(60) in the transformation process.This work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch.
文摘Since neodymium magnet possesses an extremely strong magnetic field, resulting from the combination of neodymium, iron and boron, it has become the most used in designing autonomous sumo robots. When it is mounted under the structure of this robot, the magnet produces a large amount of normal force resulting from the interaction between its field lines and the steel frame of the arena, reducing the risk of slipping its wheels. Thus, the heavier a robot, the greater the difficulty for the opponent to remove it from the arena. This article explains the properties of Nd-Fe-Br magnets and analyzes the influence of these characteristics in the relation induction/weight. Additionally, to a comparative analysis, this research analyzes the positioning, geometry and polarization of the magnets under study, based on numerical results obtained using Inventor and K ＆ J Magnets Calculator software, given that these factors influence in their energetic product generation. Furthermore, more than just working with what we believe is a subject of great interest for sumo robot＇s teams, this study encourages their competitiveness, an essential factor for the competition.
