It has been reported that the ply gap influences the ballistic resistance of spaced multi-ply fabric systems,but its working mechanism was not well-understood. This paper reports the experimental and numerical approac...It has been reported that the ply gap influences the ballistic resistance of spaced multi-ply fabric systems,but its working mechanism was not well-understood. This paper reports the experimental and numerical approaches and results of an investigation on the mechanisms that enable the improved ballistic performance of spaced multi-ply systems. Penetration tests were performed over a range of impact velocities ranging from 200 m/s to 400 m/s. The results confirmed that the ply gap is beneficial to the energy absorption capability of the systems. This is because the front plies tend to absorb more energy when they are not immediately constrained by the rear plies. During a ballistic event, the gap relieves the reflection of the compressive pulse, prolonging the projectile engagement time with the front plies;on the other hand, the rear plies become increasingly less active in dissipating energy as the gap increases.When the gap is sufficiently widened to avoid any interference between the plies before the failure of the front ply, the responses of the whole system no longer vary. It was also found that the ballistic performance of the spaced systems is influenced by ply thickness, impact velocity, and the stacking order of the ply gap.展开更多
In this article, a new type of coagulant material has been investigated and the performance of the coagulation process using this type of coagulant was evaluated. This new type is a combination of zinc oxide nanoparti...In this article, a new type of coagulant material has been investigated and the performance of the coagulation process using this type of coagulant was evaluated. This new type is a combination of zinc oxide nanoparticles and polyferric sulfate (ZnOPFS). The structure of zinc oxide nanoparticles was determined by spectroscopic, X-ray and electron microscopy methods, and based on this, it was determined that ZnOPFS is a complex and mixed compound that is mainly composed of zinc oxide nanoparticles and ferric sulfate. The effects of Zn/Fe (Zn/Fe) molar ratio and aging (time) on acidity and zeta potential were also evaluated using a specific method. The obtained results showed that in the simultaneous deposition process, zinc ions can prevent the formation of polyferric acid coagulation and subsequently improve the stability of ZnOPFS.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 51708553, 12202498, 52371299,12302187)Natural Science Foundations of Jiangsu Province (Grant No. BK20210438)Knowledge Innovation Program of WuhanShuguang Project (Grant No. 202201080102)。
文摘It has been reported that the ply gap influences the ballistic resistance of spaced multi-ply fabric systems,but its working mechanism was not well-understood. This paper reports the experimental and numerical approaches and results of an investigation on the mechanisms that enable the improved ballistic performance of spaced multi-ply systems. Penetration tests were performed over a range of impact velocities ranging from 200 m/s to 400 m/s. The results confirmed that the ply gap is beneficial to the energy absorption capability of the systems. This is because the front plies tend to absorb more energy when they are not immediately constrained by the rear plies. During a ballistic event, the gap relieves the reflection of the compressive pulse, prolonging the projectile engagement time with the front plies;on the other hand, the rear plies become increasingly less active in dissipating energy as the gap increases.When the gap is sufficiently widened to avoid any interference between the plies before the failure of the front ply, the responses of the whole system no longer vary. It was also found that the ballistic performance of the spaced systems is influenced by ply thickness, impact velocity, and the stacking order of the ply gap.
文摘In this article, a new type of coagulant material has been investigated and the performance of the coagulation process using this type of coagulant was evaluated. This new type is a combination of zinc oxide nanoparticles and polyferric sulfate (ZnOPFS). The structure of zinc oxide nanoparticles was determined by spectroscopic, X-ray and electron microscopy methods, and based on this, it was determined that ZnOPFS is a complex and mixed compound that is mainly composed of zinc oxide nanoparticles and ferric sulfate. The effects of Zn/Fe (Zn/Fe) molar ratio and aging (time) on acidity and zeta potential were also evaluated using a specific method. The obtained results showed that in the simultaneous deposition process, zinc ions can prevent the formation of polyferric acid coagulation and subsequently improve the stability of ZnOPFS.
