As more and more Chinese students are trying to study abroad, IELTS becomes one of the most important tests all around China. After years’development, IELTS speaking teaching still meets certain difficulties. This pa...As more and more Chinese students are trying to study abroad, IELTS becomes one of the most important tests all around China. After years’development, IELTS speaking teaching still meets certain difficulties. This paper gives specific advice based on certain applied linguistics theory, i. e. Grammar-translation Method, Audiolingualism, and Natural Order Hypothesis, trying to provide enlightenment for future IELTS speaking teaching.展开更多
Roller bearings support heavy loads by riding on an ultra-thin oil film(between the roller and raceway),the thickness of which is critical as it reflects the lubrication performance.Ultrasonic interfacial reflection,w...Roller bearings support heavy loads by riding on an ultra-thin oil film(between the roller and raceway),the thickness of which is critical as it reflects the lubrication performance.Ultrasonic interfacial reflection,which facilitates the non-destructive measurement of oil-film thickness,has been widely studied.However,insufficient spatial resolution around the rolling line contact zone remains a barrier despite the use of miniature piezoelectric transducers.In this study,a finite-element-aided method is utilized to simulate wave propagation through a three-layered structure of roller-oil-raceway under elastohydrodynamic lubrication(EHL)with nonlinear characteristics of the i)deformed curvature of the cylindrical roller and ii)nonuniform distribution of the fluid bulk modulus along the circumference of the oil layer being considered.A load and speed-dependent look-up table is then developed to establish an accurate relationship between the overall reflection coefficient(directly measured by an embedded ultrasonic transducer)and objective variable of the central oil-film thickness.The proposed finite-element-aided method is verified experimentally in a rollerraceway test rig with the ultrasonically measured oil-flm thickness corresponding to the values calculated using the EHLtheory.展开更多
随着计算机应用在各个领域的不断深入,《计算机辅助设计》课程已在大学的许多专业开设。由于课时的限制及各专业对该课程教学内容的不确定性,如何高效地上好该课程已成为人们关注的重要问题。文章论述了《计算机辅助设计》课程问题中心...随着计算机应用在各个领域的不断深入,《计算机辅助设计》课程已在大学的许多专业开设。由于课时的限制及各专业对该课程教学内容的不确定性,如何高效地上好该课程已成为人们关注的重要问题。文章论述了《计算机辅助设计》课程问题中心型教学方法(TLMCBP,Teaching and Learning Method of Central Based Problems)的具体实施途径,提出了问题中心型开闭环耦合的基本教学模式,并在此基础上进行了教学实践和理论研究,取得了理想的教学效果。展开更多
文摘As more and more Chinese students are trying to study abroad, IELTS becomes one of the most important tests all around China. After years’development, IELTS speaking teaching still meets certain difficulties. This paper gives specific advice based on certain applied linguistics theory, i. e. Grammar-translation Method, Audiolingualism, and Natural Order Hypothesis, trying to provide enlightenment for future IELTS speaking teaching.
文摘Roller bearings support heavy loads by riding on an ultra-thin oil film(between the roller and raceway),the thickness of which is critical as it reflects the lubrication performance.Ultrasonic interfacial reflection,which facilitates the non-destructive measurement of oil-film thickness,has been widely studied.However,insufficient spatial resolution around the rolling line contact zone remains a barrier despite the use of miniature piezoelectric transducers.In this study,a finite-element-aided method is utilized to simulate wave propagation through a three-layered structure of roller-oil-raceway under elastohydrodynamic lubrication(EHL)with nonlinear characteristics of the i)deformed curvature of the cylindrical roller and ii)nonuniform distribution of the fluid bulk modulus along the circumference of the oil layer being considered.A load and speed-dependent look-up table is then developed to establish an accurate relationship between the overall reflection coefficient(directly measured by an embedded ultrasonic transducer)and objective variable of the central oil-film thickness.The proposed finite-element-aided method is verified experimentally in a rollerraceway test rig with the ultrasonically measured oil-flm thickness corresponding to the values calculated using the EHLtheory.
文摘随着计算机应用在各个领域的不断深入,《计算机辅助设计》课程已在大学的许多专业开设。由于课时的限制及各专业对该课程教学内容的不确定性,如何高效地上好该课程已成为人们关注的重要问题。文章论述了《计算机辅助设计》课程问题中心型教学方法(TLMCBP,Teaching and Learning Method of Central Based Problems)的具体实施途径,提出了问题中心型开闭环耦合的基本教学模式,并在此基础上进行了教学实践和理论研究,取得了理想的教学效果。
