Abstract: The present invention discloses a concrete-encased concrete-filled steel tube (CFST) column connection structure, a concrete-encased CFST column comprising such a connection structure, and a construction method for constructing such a concrete-encased CFST column, in the technical field of connection of concrete-encased CFST columns. Exposed steel tubes at the connection ends of two split concrete-encased CFST columns are connected through a core positioning sleeve of a concrete-encased CFST column connection structure. Exposed longitudinal bars of the two split concrete-encased CFST columns are connected through longitudinal bar sleeves of the concrete-encased CFST column connection structure. A space between the two split concrete-encased CFST columns is sealed by an external sealing sleeve of the concrete-encased CFST column connection structure; and the space in the external sealing sleeve and around the first and second exposed steel tubes is filled with a concrete slurry.

Abstract: The present invention discloses a concrete-encased concrete-filled steel tube (CFST) column connection structure, a concrete-encased CFST column comprising such a connection structure, and a construction method for constructing such a concrete-encased CFST column, in the technical field of connection of concrete-encased CFST columns. Exposed steel tubes at the connection ends of two split concrete-encased CFST columns are connected through a core positioning sleeve of a concrete-encased CFST column connection structure. Exposed longitudinal bars of the two split concrete-encased CFST columns are connected through longitudinal bar sleeves of the concrete-encased CFST column connection structure. A space between the two split concrete-encased CFST columns is sealed by an external sealing sleeve of the concrete-encased CFST column connection structure; and the space in the external sealing sleeve and around the first and second exposed steel tubes is filled with a concrete slurry.

Abstract: The present invention relates to a method for continuous production of carbon nanotubes in a nano-agglomerate fluidized bed, which comprises the following steps: loading transition metal compounds on a support, obtaining supported nanosized metal catalysts by reducing or dissociating, catalytically decomposing a carbon-source gas, and growing carbon nanotubes on the catalyst support by chemical vapor deposition of carbon atoms. The carbon nanotubes are 4˜100 nm in diameter and 0.5˜1000 ?m in length. The carbon nanotube agglomerates, ranged between 1˜1000 ?m, are smoothly fluidized under 0.005 to 2 m/s superficial gas velocity and 20-800 kg/m3 bed density in the fluidized-bed reactor. The apparatus is simple and easy to operate, has a high reaction rate, and it can be used to produce carbon nanotubes with high degree of crystallization, high purity, and high yield.

Abstract: The present invention relates to a method for continuous production of carbon nanotubes in a nano-agglomerate fluidized bed, which comprises the following steps: loading transition metal compounds on a support, obtaining supported nanosized metal catalysts by reducing or dissociating, catalytically decomposing a carbon-source gas, and growing carbon nanotubes on the catalyst support by chemical vapor deposition of carbon atoms. The carbon nanotubes are 4˜100 nm in diameter and 0.5˜1000 ?m in length. The carbon nanotube agglomerates, ranged between 1˜1000 ?m, are smoothly fluidized under 0.005 to 2 m/s superficial gas velocity and 20˜800 kg/m3 bed density in the fluidized-bed reactor. The apparatus is simple and easy to operate, has a high reaction rate, and it can be used to produce carbon nanotubes with high degree of crystallization, high purity, and high yield.

Abstract: The present invention relates to a method for continuous production of carbon nanotubes in a nano-agglomerate fluidized bed, which comprises the following steps: loading transition metal compounds on a support, obtaining supported nanosized metal catalysts by reducing or dissociating, catalytically decomposing a carbon-source gas, and growing carbon nanotubes on the catalyst support by chemical vapor deposition of carbon atoms. The carbon nanotubes are 4˜100 nm in diameter and 0.5˜1000 &mgr;m in length. The carbon nanotube agglomerates, ranged between 1˜1000 &mgr;m, are smoothly fluidized under 0.005 to 2 m/s superficial gas velocity and 20˜800 kg/m3 bed density in the fluidized-bed reactor. The apparatus is simple and easy to operate, has a high reaction rate, and it can be used to produce carbon nanotubes with high degree of crystallization, high purity, and high yield.

Abstract: Disclosed is a process for continuous alkylation of aromatics or their derivatives in the presence of a solid acid catalyst in a liquid-solid circulating fluidized bed system, said system comprising a liquid-solid cocurrent upflow reactor, a sedimentation washing tower for the used catalyst, a liquid-solid cocurrent upflow regenerator, a sedimentation washing tower for the regenerated catalyst, and two vortical liquid-solid separators. By regeneration of the used catalyst, continuous alkylation process is achieved in this system.