A method of making a multilayer filter and the multilayer filter made by the method. The method includes generally two steps. The first step is to coat a layer of nanofibers on a single side or both sides of a substrate medium to obtain a composite filter medium, and the second step is to fold the c.....
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Ammonia (NH3) and odorous smell (nitrogen containing compounds) in the air are contaminants and are harmful to human health. Since more and more people concern for the indoor air quality after the outbreak of SARS, methods have been developed to eliminate the contaminants.Conventional supported meta.....
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The present invention provides a piezoelectric ceramic composition, especially a lead-free piezoelectric ceramic composition, with a suitable amount of CeO2 or CeO2-containing complex additives, which is represented by the following formula: (Na0.475K0.475Li0.05)(Nb1-xAx)O3+yCeO2+zBO2 wherein “A” re.....
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