数学"情境与提出问题"教学与RME教学之比较研究     

陈艳斌  朱维宗  吕传汉 《数学教育学报》2006,15(4):59-61

RME与数学“情境与提出问题”两种教学模式都是在进行数学教育改革过程中出现的,都旨在让学生在数学方面有更多的发展,培养学生的创新精神和解决问题的能力.两种教学模式在理论基础、“情境问题”、学生数学学习过程、数学思维的培养、教学过程中学生与教师的地位以及教材等方面各有其侧重点。  相似文献   

Evaluating the effect of midpalatal corticotomy-assisted rapid maxillary expansion on the upper airway in young adults using computational fluid dynamics     

Juan LI  Lingfang SHI  Xiayao ZHANG  Luxi WENG  Hong CHEN  Jun LIN 《Journal of Zhejiang University. Science. B》2021,22(2):146

Midpalatal corticotomy-assisted rapid maxillary expansion(MCRME)is a minimally invasive treatment of maxillary transverse deficiency(MTD)in young adults.However,the effect of MCRME on respiratory function still needs to be determined.In this study,we evaluated the changes in maxillary morphology and the upper airway following MCRME using computational fluid dynamics(CFD).Twenty patients with MTD(8 males,12 females;mean age 20.55 years)had cone-beam computed tomography(CBCT)images taken before and after MCRME.The CBCT data were used to construct a threedimensional(3 D)upper airway model.The upper airway flow characteristics were simulated using CFD,and measurements were made based on the CBCT images and CFD.The results showed that the widths of the palatal bone and nasal cavity,and the intermolar width were increased significantly after MCRME.The volume of the nasal cavity and nasopharynx increased significantly,while there were no obvious changes in the volumes of the oropharynx and hypopharynx.CFD simulation of the upper airway showed that the pressure drop and maximum velocity of the upper airway decreased significantly after treatment.Our results suggest that in these young adults with MTD,increasing the maxillary width,upper airway volume,and quantity of airflow by MCRME substantially improved upper airway ventilation.  相似文献