Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in th...Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in this era of technology.Instruction-assisted 3D technology can display stereo graphics and promote students'understanding of the geometrical structure and characteristics of graphics.Spatial ability includes several aspects.Few software programs are available for training different aspects of spatial ability for senior high school students.This study aims to explore an effective method for training the spatial ability for senior high school students,and to promote the development of students'independent inquiry ability.Methods First,an inquiry design strategy to improve the spatial ability of students is proposed.Based on this strategy,unity3D was used to develop a 3D inquiry environment that can use leap motion to complete a gesture interaction.Finally,researchers carried out experience-based activities and issued user experience questionnaires to participants to verify the application effect of the spatial ability inquiry environment and used interviews to understand the user experience of participants exploring the leap motion device in a 3D inquiry environment.Results 32 learners participated in the experiment.learners have a high score for perceived usefulness and willingness to use.Compared with the perceived ease of use and perceived usefulness,the average score of the application effect is relatively low.In terms of willingness to use,most of the learners expressed their willingness to use a similar inquiry environment for spatial ability training in the future.Conclusions The spatial ability inquiry environment can help learners better understand different concepts.The users showed a strong willingness to continue using the device.The device also updates the teaching concept to a certain extent and emphasizes the dominant position of a student.展开更多
Intramedullary schwannoma of the upper cervical spinal cord is rarely reported in forensic medicine.We herein report a case involving a patient who died of compression from an intramedullary schwannoma in the upper ce...Intramedullary schwannoma of the upper cervical spinal cord is rarely reported in forensic medicine.We herein report a case involving a patient who died of compression from an intramedullary schwannoma in the upper cervical spinal cord.A 30-year-old man initially presented with a five-day history of pain in the left chest that progressed to weakening in the left arm.Although the patient was treated with analgesic poultices,he developed inspiratory dyspnoea and died while working the next day without having undergone any medical imaging examination or surgical treatment.Anatomical and histopathological examinations revealed an intramedullary schwannoma in the left cervical spinal cord(C_(3)-C_(5))underneath the spinal nerve root.The cause of death might have been asphyxia secondary to the tumour,which interfered with the nerve function in the respiratory muscles.This finding suggests that an autopsy is essential for pathologists and medicolegists to comprehensively undertake their due obligation to obtain“the first evidence”,especially when there is a lack of directly related evidence.As part of the central nervous system,the spinal cord could be systematically included in a routine pathological autopsy in some cases.展开更多
The dielectric breakdown（DB） model for a penny-shaped crack under a semipermeable boundary condition in a three-dimensional piezoelectric medium is studied.An approximate analytical solution is derived by using the ...The dielectric breakdown（DB） model for a penny-shaped crack under a semipermeable boundary condition in a three-dimensional piezoelectric medium is studied.An approximate analytical solution is derived by using the boundary integral equation with extended displacement discontinuity,and the corresponding boundary element method with double iterative approaches is developed to analyze the semi-permeable crack.The effect of electric boundary conditions on crack faces is discussed on the basis of DB model.By comparing the DB model with the polarization saturation（PS） model for different piezoelectric materials,some interesting phenomena related to the electric yielding zone and local J-integral are observed.展开更多
基金the National Key Research and Development Program of China(2018YFB1004903)the Key Discipline Cultivation Program of Zhejiang Province(18JYXK018).
文摘Background Spatial ability is an unique type of intelligence;it can be distinguished from other forms of intelligence and plays an essential role in an individual's success in many academic fields,particular in this era of technology.Instruction-assisted 3D technology can display stereo graphics and promote students'understanding of the geometrical structure and characteristics of graphics.Spatial ability includes several aspects.Few software programs are available for training different aspects of spatial ability for senior high school students.This study aims to explore an effective method for training the spatial ability for senior high school students,and to promote the development of students'independent inquiry ability.Methods First,an inquiry design strategy to improve the spatial ability of students is proposed.Based on this strategy,unity3D was used to develop a 3D inquiry environment that can use leap motion to complete a gesture interaction.Finally,researchers carried out experience-based activities and issued user experience questionnaires to participants to verify the application effect of the spatial ability inquiry environment and used interviews to understand the user experience of participants exploring the leap motion device in a 3D inquiry environment.Results 32 learners participated in the experiment.learners have a high score for perceived usefulness and willingness to use.Compared with the perceived ease of use and perceived usefulness,the average score of the application effect is relatively low.In terms of willingness to use,most of the learners expressed their willingness to use a similar inquiry environment for spatial ability training in the future.Conclusions The spatial ability inquiry environment can help learners better understand different concepts.The users showed a strong willingness to continue using the device.The device also updates the teaching concept to a certain extent and emphasizes the dominant position of a student.
文摘Intramedullary schwannoma of the upper cervical spinal cord is rarely reported in forensic medicine.We herein report a case involving a patient who died of compression from an intramedullary schwannoma in the upper cervical spinal cord.A 30-year-old man initially presented with a five-day history of pain in the left chest that progressed to weakening in the left arm.Although the patient was treated with analgesic poultices,he developed inspiratory dyspnoea and died while working the next day without having undergone any medical imaging examination or surgical treatment.Anatomical and histopathological examinations revealed an intramedullary schwannoma in the left cervical spinal cord(C_(3)-C_(5))underneath the spinal nerve root.The cause of death might have been asphyxia secondary to the tumour,which interfered with the nerve function in the respiratory muscles.This finding suggests that an autopsy is essential for pathologists and medicolegists to comprehensively undertake their due obligation to obtain“the first evidence”,especially when there is a lack of directly related evidence.As part of the central nervous system,the spinal cord could be systematically included in a routine pathological autopsy in some cases.
基金Project supported by the National Natural Science Foundation of China(Nos.11102186 and 11272290)the Science and Technology Key Project of Henan(No.132102210412)
文摘The dielectric breakdown（DB） model for a penny-shaped crack under a semipermeable boundary condition in a three-dimensional piezoelectric medium is studied.An approximate analytical solution is derived by using the boundary integral equation with extended displacement discontinuity,and the corresponding boundary element method with double iterative approaches is developed to analyze the semi-permeable crack.The effect of electric boundary conditions on crack faces is discussed on the basis of DB model.By comparing the DB model with the polarization saturation（PS） model for different piezoelectric materials,some interesting phenomena related to the electric yielding zone and local J-integral are observed.
