Measurement methods and applications of high-medium-efficiency and sub-high-efficiency air filter arrestance
                        
                        The replacement and maintenance method of sand net and the evaluation method of sand net
                        
                        Air filtration device and its use
                        
                        Electrostatic dust removal device and its manufacturing method and use
                        
                        Plant fiber sand blocking and fixing net and its preparation method
                        
                        Variable wind resistance sand blocking and fixing net
                        
                        Ring filter and its preparation process
                        
                        Fixed components of sand net
                        
                        Polymer masterbatch containing anti-mite agent, monofilament for anti-mite air filter and its preparation process and use