粒子播放一次后销毁:
//ref: http://answers.unity3d.com/questions/219609/auto-destroying-particle-system.html
//ref: http://answers.unity3d.com/questions/41855/cannot-implicitly-convert-type-unityengineobject-t.html
particle.GetComponent<ParticleSystem> ().Stop ();
particle.GetComponent<ParticleSystem> ().Play ();
float particleDurTime = particle.GetComponent<ParticleSystem> ().duration + particle.GetComponent<ParticleSystem> ().startLifetime;
Destroy (particle, particleDurTime);