The frame of electro-mechanical safety and arming device (S&A) is established, and the electro-mechanical S&A for the mortar shell fuze is designed at the end of the paper.

最后构建了引信机电式安全系统的系统框架，并结合迫击炮弹引信开展了机电式安全系统的设计。

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A heavy mortar roared, sending a shell high over the harbor at Charleston,South Carolina.

VOA: special.2009.08.13

On Tuesday, the Israeli military said a mortar shell exploded on its side of the frontier in the Golan Heights.

NPR: Israel Says It Will Not Let Gaza Rockets Continue

Seven US Marines have been killed and eight injured after a mortar shell exploded unexpectedly in a training accident in the US state of Nevada.

BBC: Brig Gen Jim Lukeman

Both young men were among seven members of the 2nd Marine Expeditionary Force killed late Monday when a mortar shell exploded in its firing tube during an exercise at Hawthorne Army Depot in Nevada.

NPR: Marines Killed In Training Were Young, Lives Ahead