BACKGROUND: The purpose of this study was to evaluate the sensitometric characteristics of Ultraspeed, Ektaspeed Plus and Insight dental radiographic films using manual and automatic processing systems. METHODS: In this experimental invitro study, an aluminum step-wedge was used to construct characteristic curves for D-, E- and F-speed radiographic films (Kodak Eastman, Rochester, USA). All fil...

At present, the noise of pure electric vehicles is a research hotspot, especially automatic transmission. In order to reduce problem in test, this paper proposes method optimize local structure gearbox housing. First, evaluated and analyzed by combining subjective objective methods, score information are obtained. Then factors that have great influence on transmission error explored, housing fi...