The one-dimensional problem of the motion of the rigid plate under explosive attack has an analytic solution only when the polytropic index of detonation product equals to three.

刚性飞片在炸药爆炸作用下的一维抛掷问题，仅当爆炸气体多方指数等于三时可以求得解析解；

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Officials say he bought materials to build explosive devices and traveled to New York City on September tenth as part of planning for an attack.

VOA: special.2009.10.17

He said security in Helmand was improving, with Afghan forces now responsible for the bulk of the province - but that the environment in which UK troops operated remained "risky and dangerous including the threat of improvised explosive devices and insurgent attack".

BBC: Afghanistan roadside bomb kills three British soldiers

Federal investigators said that they suspect the two brothers may have been planning to launch another attack when they were chased by police, and that they had about half dozen additional explosive devices with them.

WSJ: Dzhokhar Tsarnaev Charged by U.S. Prosecutors in Boston Marathon Attack

Federal investigators said that they suspect the two brothers may have been planning to launch another attack when they were chased by police, and that they had about a half-dozen additional explosive devices with them.

WSJ: Dzhokhar Tsarnaev Charged by U.S. Prosecutors in Boston Marathon Attack