Objective:To investigate the influence of axial length(AL),corneal curvature(CR),and the ratio of axial length to corneal radius of curvature(AL/CR)on myopia in children,and to evaluate the accuracy and specificity of...Objective:To investigate the influence of axial length(AL),corneal curvature(CR),and the ratio of axial length to corneal radius of curvature(AL/CR)on myopia in children,and to evaluate the accuracy and specificity of AL/CR in diagnosing myopia in children.Methods:A cross-sectional study was conducted.A total of 200 children(400 eyes)aged 6-12 years were recruited from the ophthalmology outpatient clinic of Fuling District People’s Hospital from December 2022 to December 2023.AL,CR,and AL/CR were measured,and comprehensive optometry was performed under cycloplegia,with the results recorded in spherical equivalent(SE)form.Results:A total of 200 subjects(400 eyes)were included in this study,of which 330 eyes(82.50%)were myopic.No significant differences in CR were observed among different refractive groups,while significant differences were noted in SE,AL,and AL/CR.The AL and AL/CR ratios were higher in myopic eyes compared to emmetropic and hyperopic eyes.Using cycloplegia as the gold standard,SE in the myopia group was correlated with AL,AL/CR,and CR,with stronger correlations observed with AL and AL/CR.An AL/CR value>3 demonstrated a sensitivity of 0.918,specificity of 0.786,misdiagnosis rate of 0.214,missed diagnosis rate of 0.082,and accuracy of 89.5%in diagnosing myopia.Conclusion:AL and AL/CR values are highly correlated with SE,with the strongest correlation observed in the myopia group.The AL/CR value exhibits high diagnostic value in determining myopia in children.展开更多
For a generalized radiation problem,an infinitely long submerged horizontal cylinder is forced to vibrate periodically in the transverse direction,with a described elastic harmonic motion along its longitudinal direct...For a generalized radiation problem,an infinitely long submerged horizontal cylinder is forced to vibrate periodically in the transverse direction,with a described elastic harmonic motion along its longitudinal direction.A critical frequency corresponds to the described wave number of elastic vibration,and the generalized hydrodynamic coefficients abruptly change in the vicinity of critical frequency.In this work,a numerical examination is carried out to study the characteristics of wave profiles and wave propagation in the vicinity of the critical frequency.Results show that below the critical frequency,the real parts of complex wave profiles have large values in the vicinity of the cylinder and decay to zero with the increasing distance from the cylinder.Meanwhile,the imaginary parts of complex wave profiles are all zero,which explains why the generalized radiation damping is zero when the vibration is less than the critical frequency.At far distances,no radiation wave is observed.When the vibration exceeds the critical frequency,the real and imaginary parts of the wave profiles oscillate harmonically and keep steady amplitudes.In addition,the generated radiation wave propagates obliquely outward.The influence of the cylinder’s submergence depth on the wave profile is also studied,and the results indicate that the amplitude of the wave profile decreases as the submergence depth of the cylinder increases.The 3D wave profiles are graphically presented to show the wave propagation characteristics in the vicinity of the critical frequency for this generalized radiation problem.This study provides a good reference for the interaction between fluid and slender elastic structures.展开更多
The quality and safety crisis of agricultural products on the one hand is the crisis of harm of agricultural products,and on the other hand is the crisis of information dissemination. This paper analyzed the character...The quality and safety crisis of agricultural products on the one hand is the crisis of harm of agricultural products,and on the other hand is the crisis of information dissemination. This paper analyzed the characteristics of content of the quality and safety crisis information of tropical agricultural products. On the basis of these characteristics,it came up with strategies and recommendations for solving the problems of quality and safety of tropical agricultural products,including establishing the emergency response system for quality and safety crisis of tropical agricultural products,bringing into play the social responsibilities of scientific research institutions,and bringing into play authoritative effect of scientific experts.展开更多
基金Chongqing Fuling District Science and Health Joint Medical Research Project(2022KWLH069)。
文摘Objective:To investigate the influence of axial length(AL),corneal curvature(CR),and the ratio of axial length to corneal radius of curvature(AL/CR)on myopia in children,and to evaluate the accuracy and specificity of AL/CR in diagnosing myopia in children.Methods:A cross-sectional study was conducted.A total of 200 children(400 eyes)aged 6-12 years were recruited from the ophthalmology outpatient clinic of Fuling District People’s Hospital from December 2022 to December 2023.AL,CR,and AL/CR were measured,and comprehensive optometry was performed under cycloplegia,with the results recorded in spherical equivalent(SE)form.Results:A total of 200 subjects(400 eyes)were included in this study,of which 330 eyes(82.50%)were myopic.No significant differences in CR were observed among different refractive groups,while significant differences were noted in SE,AL,and AL/CR.The AL and AL/CR ratios were higher in myopic eyes compared to emmetropic and hyperopic eyes.Using cycloplegia as the gold standard,SE in the myopia group was correlated with AL,AL/CR,and CR,with stronger correlations observed with AL and AL/CR.An AL/CR value>3 demonstrated a sensitivity of 0.918,specificity of 0.786,misdiagnosis rate of 0.214,missed diagnosis rate of 0.082,and accuracy of 89.5%in diagnosing myopia.Conclusion:AL and AL/CR values are highly correlated with SE,with the strongest correlation observed in the myopia group.The AL/CR value exhibits high diagnostic value in determining myopia in children.
基金supported by the National Key Research and Development Program of China(2022YFB2602800)National Natural Science Foundation of China(No.52271261).
文摘For a generalized radiation problem,an infinitely long submerged horizontal cylinder is forced to vibrate periodically in the transverse direction,with a described elastic harmonic motion along its longitudinal direction.A critical frequency corresponds to the described wave number of elastic vibration,and the generalized hydrodynamic coefficients abruptly change in the vicinity of critical frequency.In this work,a numerical examination is carried out to study the characteristics of wave profiles and wave propagation in the vicinity of the critical frequency.Results show that below the critical frequency,the real parts of complex wave profiles have large values in the vicinity of the cylinder and decay to zero with the increasing distance from the cylinder.Meanwhile,the imaginary parts of complex wave profiles are all zero,which explains why the generalized radiation damping is zero when the vibration is less than the critical frequency.At far distances,no radiation wave is observed.When the vibration exceeds the critical frequency,the real and imaginary parts of the wave profiles oscillate harmonically and keep steady amplitudes.In addition,the generated radiation wave propagates obliquely outward.The influence of the cylinder’s submergence depth on the wave profile is also studied,and the results indicate that the amplitude of the wave profile decreases as the submergence depth of the cylinder increases.The 3D wave profiles are graphically presented to show the wave propagation characteristics in the vicinity of the critical frequency for this generalized radiation problem.This study provides a good reference for the interaction between fluid and slender elastic structures.
基金Supported by Special Project of Fundamental Research Funds for Central Public Welfare Research Institutes in Chinese Academy of Tropical Agricultural Sciences(1630012015021)Project of Natural Science Foundation of Hainan Province(714282)
文摘The quality and safety crisis of agricultural products on the one hand is the crisis of harm of agricultural products,and on the other hand is the crisis of information dissemination. This paper analyzed the characteristics of content of the quality and safety crisis information of tropical agricultural products. On the basis of these characteristics,it came up with strategies and recommendations for solving the problems of quality and safety of tropical agricultural products,including establishing the emergency response system for quality and safety crisis of tropical agricultural products,bringing into play the social responsibilities of scientific research institutions,and bringing into play authoritative effect of scientific experts.
