Dynamic mass density and acoustic metamaterials;

Considering non-spherical particles,starting from particles size distribution,the concept of the average mass was put forward,and the theoretical formula for calculating mass density of non-spherical particles was derived.

%) and Al-28%Mg-14%Zn alloys used for thermal energy storage applications,such as the specific heat capacity including solid and liquid state;the mass density in the temperature range 30～500℃;the melting temperature and the latent heat of fusion.

The design method and function characteristics for the single hydraulic prop airtight quality detecting device are introduced.

The single hydraulic prop airtight quality detecting devices have been had a great deal of applications in coal mines all over the country,however,an unified use standard has not been made.

The sealing quality of single prop affects directly the safety in production, therefore the sealing quality monitoring of single hydraulic prop, especially after being repaired heavily, appears important extremely.

In measurement of gas pressure, firedamp drainage and water injection of coal seam, it is very important to reduce leakage and to increase sealing of borehole on the basis of fluid mechanics, mechanics of sealing materials and osmotic fluid mechanics, this paper discusses the permeable mechanism of sealing medium in sealing section of borehole.

SHPB equipment and experimental techniques were used to analyze and characterize the electromechanical effect in compact bone with different length and diameter under impacting,at the same time,the potential which was induced by strain were recorded.

As a practical example, the numerical simulation of mechanical characteristics for compact bone by homogenization method is introduced.