Abstract: As a protective material, rubble concrete draws people's attention all the while for the rubble can be found and constructed easily. However the rubble strength is low, it can't resist the penetration of modern bomb. So the rubble concrete shelter is bulk and difficult to construct in the practical engineering. All of these affect its application. Because the corundum-rubble has a special mechanics performance with high-strength and high-hardness, instead of the normal rock block in the rubble concrete shelter, a composite material made of corundum-rubble and concrete for anti-penetration is developed. To study the defense performance of the material, the check experiment against the projectile was done. A total of six corundum-rubble concrete targets and three concrete targets were made , then projectiles with the diameter 125mm were launched by the tank gun to targets. The test results show the anti-penetration characteristic of the corundum-rubble concrete is excellent, and the projectiles penetrating into the corundum-rubble concrete are destroyed, deformed, or ricocheted. With the impact velocity increased, the disfeature of the corundum-rubble concrete targets doesn't enlarge clearly, which indicates the corundum-rubble concrete is effective to resist the penetration of higher velocity. Compared to the normal concrete targets of the same strength, its penetration depth is decreased largely. The single large corundum can completely block the projectile. The result can provide reference for technical application and theoretical analysis of the corundum-rubble concrete shelter.

Abstract: The rotating speed of a light rotor in a type of supercharger often reaches 90000 r/min or more. During experiments and employment of the supercharger, rubbing faults may arise, such as the journal rubs against the bearing surface and the rotating blade rubs against the stator. These faults are usually very dangerous and often make the whole system lose efficiency. In order to find the reasons, the vibration signals of the rotor bearing were recorded and analyzed by signal analysis apparatus-HP3567A. According to the spectrums of the signals, rotor vibration features were examined and the reasons that cause the rubbing faults were found.

Abstract: Longspan spatial reticulated shell structures are usually important structures, and its antiearthquake ability counts for plentiful people life and national property, so it is necessary extraordinarily for the structures to adopt some antiearthquake measures.At present, it is a new idea to combine the structural control technique with antiearthquake design of longspan reticulated shell. In the paper, the research actuality of earthquake mitigation control of longspan reticulated shell is introduced, and some important topics to be solved in the future are proposed.