Study was made on the chemical removal of phosphorus in membrane bioreactor (MBR),because insoluble metal phosphate is hard to permeate ultrafiltration membrane.

Recently, with the development of auto-control and membrane production technology, Cyclic Activated Sludge System(CASS) and Membrane Bioreactor(MBR) are given more and more attention because of their particular advantages.

Effect of Distance between Clamp and Cutting Notch on Plywood Bond Strength Testing;

Measurement of the distance between uretero and uterine neck in the condition of enlargement of uterine neck;

Study on the Correlation of Distance and Angle with the Image of Laryngostroboscope;

Joint frequency、direction of arrival and range estimation for near-field sources;

The speed of moving-target was measured based on the principle of PD frequency shift,and the range of moving-target on the pulse-echo principle.

For the accuracy of range information is higher than that of azimuth information received by networking radar system,three-dimension target location based on range only is proposed by using the linear least square iteration algorithm.

The metric and closure operator are defined,a unique topology space on is obtained.

This thesis, according to the 10-year-long lectures on the theory of metric space in different courses, summaries a few points , which should be paid attention to, on how to well explain the concepts of metric and metric space.