Robotic submarines removed the cap that had been placed on top of the leak in early June to collect the oil and send it to surface ships for collection or burning.
Beijing was shrouded in severe smog for weeks early this year, with pollutants from vehicle emissions, coal - burning in neighboring regions and construction dust.
Burning research problems on fire detection technology, such as those about combined detection, temperature detection via optical fiber, fire signal processing, early fire detection etc. are provided.