W–Cu composite combine high electrical and thermal conductivity of Cu and high arc corrosion resistance, hardness, and low thermal expansion coefficient of tungsten, and show excellent properties. Due to the distinct performance, W–Cu composites have found potential applications in electronic packaging, electric contact, aerospace, and some other high-tech areas. However, in some severe working environments, such as aerospace, micro electric manufacturing, etc, may face the issues of low relatively density and inhomogeneous microstructure.

Air quality monitoring and toxic gas emissions had risen to be a global concern in the past decades. Researchers have been trying various and massive strategies to find an effective gas sensor and its synthesis methods in this field. A practical gas sensor should detect a particular gas among a mixture of gases and continuously monitor an atmosphere. There are many types of gas sensors depend on different classification methods.

The mechanical properties of carbon nanotube composites are mainly studied by experiment, theoretical analysis and numerical method. The common methods for the mechanical properties of carbon nanotubes include amplitude calculation, cantilever/simply supported beam model, and direct methods. The mechanical parameters of carbon nanotubes are derived by classical mechanics.Solid acid catalysts play a significant part in chemical and petroleum industries in hydrocarbon conversion reactions required in octane enhancement processes, such as cracking, isomerization and alkylation, which can form highly branched isoparaffins. Such reactions need strong or moderate acid catalysts.