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In recent years, the problem of electromagnetic interference and electromagnetic compatibility has become increasingly serous, seriously endangering the safe operation of instruments, meters and other electronic equipment in the military and it is urgent to develop new high-performance electromagnetic shielding materials. Graphene Is a new type of two-dimension carbon nanostructured material with excellent sand chemical properties, which provides a new for the derign of flexible' thin and good service performance electromagnetic shielding materials. Staring from the basic principle of electromagnetic shielding, this review introduces the mochas of electromagnetic shielding and loss and the way of energy convertor. Furthermore' graphene electromagnetic shilling materials were systematically classified and summered. The shielding efficiency and research progress of graphene electromagnetic shielding materials in recent years were reviewed, and the challenges and development prospects of graphene electromagnetic shielding materials were prospected. [ABSTRACT FROM AUTHOR]

Based on the representative macroscopic volume (RMV) - considering the moisture content in the pores? the black box- grey box and white box models of heat transfer in porous media were established. According to the "three-box" model and the analysis of coupled heat and moisture transfer process- the formula of thermal conductivity was derived. Taking rock wool as an example? the effects of porosity- moisture content-pore channel distribution coefficient and tortuosity on thermal conductivity were discussed by numerical calculation of the model. The results show that porosity and pore channel distribution coefficient were negatively correlated with thermal conductivity, while moisture content and tortuosity were positively correlated with thermal conductivity. The conclusion could provide some ideas and methods for improving the heat-insulating property of materials. [ABSTRACT FROM AUTHOR]