Caving mining method

When the mine is filled with water sand or waste rock, the column is recovered by the caving method. The ground pressure control principle and use conditions of filling and caving are different, so the supporting use is very rare, but it is used to mine ore with low grade in the following

Explain what is 802.11?

In the process of our contact with the wireless industry, we often meet some professional terms. Today we talk about 802.11 that we often hear about. So what exactly is 802.11? What is its content? a bit.
The 802.11 protocol suite is a standard developed by the International I