We report a simple method for preparing copper（II） molybdate（CuMoO_4） powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing...We report a simple method for preparing copper（II） molybdate（CuMoO_4） powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the（CuMo）-precursor gel was studied by thermogravimetry–differential thermal analysis（TG–DTA）, Fourier transform infrared spectroscopy（FTIR）, and X-ray diffraction（XRD）. We observed that the crystallization of CuMoO_4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m^2/g. The average grain size increased with increasing annealing temperature. The as-prepared CuMoO_4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO_4^（2-）] complex anions. We also observed that the photoluminescence intensity increased with increasing crystallite size.展开更多
The CBCM (Controlled Behaviour Composite Material) is a thermal active composite, which has been developed for morphing applications. The thermal activation is made by a source of heating generated within the composit...The CBCM (Controlled Behaviour Composite Material) is a thermal active composite, which has been developed for morphing applications. The thermal activation is made by a source of heating generated within the composite structure. The coupling between the induced thermal field and the thermomechanical properties of the various components of the composite structure leads to the change of the structure shape. The heat source is generated by Joule effect, Carbon yarns inserted in the composite, are connected to a power supply. The application field of CBCM technology is the domain of shape modification and active assembly. The objective of this work is to illustrate the capabilities of CBCM in the domain of vibration control. We will study several reference plates with different constitution. The influences of these different constitutions, of the CBCM effect and the loss of stiffness for the matrix will be highlighted, for two boundary conditions, free/free and embedded/embedded.展开更多
基金supported by two French-Moroccan projects: Volubilis Partenariat Hubert Curien (PHC No.MA 09 205)Projet de Recherches Convention Internationale du CNRS (CNRS-CNRST No.w22572)
文摘We report a simple method for preparing copper（II） molybdate（CuMoO_4） powders via a combustion-like process. A gel was first prepared by the polymerizable complex method, where citric acid was used as a complexing and polymerizing agent and nitric acid was used as an oxidizing agent. The thermal decomposition behavior of the（CuMo）-precursor gel was studied by thermogravimetry–differential thermal analysis（TG–DTA）, Fourier transform infrared spectroscopy（FTIR）, and X-ray diffraction（XRD）. We observed that the crystallization of CuMoO_4 powder was completed at 450°C. The obtained homogeneous powder was composed of grains with sizes in the range from 150 to 500 nm and exhibited a specific surface area of approximately 5 m^2/g. The average grain size increased with increasing annealing temperature. The as-prepared CuMoO_4 crystals showed a strong green photoluminescence emission at room temperature under excitation at 290 nm, which we mainly interpreted on the basis of the Jahn-Teller effect on [MoO_4^（2-）] complex anions. We also observed that the photoluminescence intensity increased with increasing crystallite size.
文摘The CBCM (Controlled Behaviour Composite Material) is a thermal active composite, which has been developed for morphing applications. The thermal activation is made by a source of heating generated within the composite structure. The coupling between the induced thermal field and the thermomechanical properties of the various components of the composite structure leads to the change of the structure shape. The heat source is generated by Joule effect, Carbon yarns inserted in the composite, are connected to a power supply. The application field of CBCM technology is the domain of shape modification and active assembly. The objective of this work is to illustrate the capabilities of CBCM in the domain of vibration control. We will study several reference plates with different constitution. The influences of these different constitutions, of the CBCM effect and the loss of stiffness for the matrix will be highlighted, for two boundary conditions, free/free and embedded/embedded.
