This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and...This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and mechanical parameters.Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system.Each femoral head was divided into 12 sub-regions according to the trabecular orientation.One 125 mm^3 trabecular cubic model was reconstructed from each sub-region.A total of 81 trabecular models were reconstructed,except three destroyed sub-regions from two femoral heads during the surgery.Trabecular morphological parameters,i.e.trabecular separation（Tb.Sp）,trabecular thickness（Tb.Th）,specific bone surface（BS/B V）,bone volume fraction（BV/TV）,structural model index（SMI）,and degree of anisotropy（DA） were measured.Micro-finite element analyses were performed for each cube to obtain the apparent Young＇s modulus and tissue level von Mises stress distribution under 1%compressive strain along three orthogonal directions,respectively.Results revealed significant regional variations in the morphological parameters（P〈0.05）.Young＇s moduli along the trabecular orientation were significantly higher than those along the other two directions.In general,trabecular mechanical properties in the medial region were lower than those in the lateral region.Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV,BV/TV,Tb.Th,and DA.In this study,regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level.The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly.展开更多
In this paper, a new technique of capturing the images of debris inlubrication or hydraulic oil using micro-imaging and computer vision techniques is introduced. Byway of image processing, the size and distribution of...In this paper, a new technique of capturing the images of debris inlubrication or hydraulic oil using micro-imaging and computer vision techniques is introduced. Byway of image processing, the size and distribution of debris are obtained, and then the oilcontamination level is also obtained. Because the information of oil contamination is obtaineddirectly from the images of debris by this method, the monitoring result is more intuitive andreliable.展开更多
It has become general for surface waters being polluted by micro organic compounds. In order to know the current pollution situation and the properties of micro organic compounds in the Changjiang River, a test was pe...It has become general for surface waters being polluted by micro organic compounds. In order to know the current pollution situation and the properties of micro organic compounds in the Changjiang River, a test was performed on micro organic compounds in the water, bottom material and fish bodies which were sampled from major city river reaches of the Changjiang River. Based on the test result, researchers described and analyzed the sorts, concentration level and distribution features of micro organic compounds. A comprehensive evaluation was conducted by adopting the method of MEG (Multimedia Environmental Goals). The study indicated that ① the water body of major city river reaches of the Changjiang River has been generally polluted. In the test, totally 12 types with 308 kinds of organic compounds were detected. The main pollutants were paraffins, PAHs and lipids; and ② micro organic pollutant content in fish bodies was generally higher than that in bottom material which is in turn higher than that in water; and ③ pollution is relatively severe in the river reaches of mid-to-large comprehensive industrial cities with fairly great TAS (Total Ambient Severity) of public health and ecological system.展开更多
For English education primary school,English vocabulary teaching should be attach importance to because in the traditional class of English vocabulary teaching,teachers just fill young minds with knowledge points of e...For English education primary school,English vocabulary teaching should be attach importance to because in the traditional class of English vocabulary teaching,teachers just fill young minds with knowledge points of each word in a 35-minute class yet fail to lay emphasis of learners’meaningful learning and autonomic learning as well as their very limited attention spans.To support traditional English vocabulary teaching classes,the research proposes the theme-based English vocabulary micro-lectures designed on the basis of experiential learning theory and constructivist learning theory as well as the analyses of target users of high-level students in the primary school.After application of the micro-lectures into practice,the research assesses the effect of the micro-lectures on the learners and then makes suggestions for design principles of theme-based vocabulary micro-lectures about selection of contents and vocabulary themes,supplementary teaching activities and teacher interaction in the micro-lectures for high-level students in the primary school.Also,the designers should make multi-level English vocabulary micro-lectures according to learners’English proficiency and increase repetition rates of vocabularies in the micro-lectures.展开更多
基金supported by the National Natural Science Foundation of China(Nos.11322223,11432016,81471753 and 11272134)the 973 Program(No.2012CB821202)
文摘This study aims to investigate the regional variations of trabecular morphological parameters and mechanical parameters of the femoral head,as well as to determine the relationship between trabecular morphological and mechanical parameters.Seven femoral heads from patients with fractured proximal femur were scanned using a micro-CT system.Each femoral head was divided into 12 sub-regions according to the trabecular orientation.One 125 mm^3 trabecular cubic model was reconstructed from each sub-region.A total of 81 trabecular models were reconstructed,except three destroyed sub-regions from two femoral heads during the surgery.Trabecular morphological parameters,i.e.trabecular separation（Tb.Sp）,trabecular thickness（Tb.Th）,specific bone surface（BS/B V）,bone volume fraction（BV/TV）,structural model index（SMI）,and degree of anisotropy（DA） were measured.Micro-finite element analyses were performed for each cube to obtain the apparent Young＇s modulus and tissue level von Mises stress distribution under 1%compressive strain along three orthogonal directions,respectively.Results revealed significant regional variations in the morphological parameters（P〈0.05）.Young＇s moduli along the trabecular orientation were significantly higher than those along the other two directions.In general,trabecular mechanical properties in the medial region were lower than those in the lateral region.Trabecular mechanical parameters along the trabecular orientation were significantly correlated with BS/BV,BV/TV,Tb.Th,and DA.In this study,regional variations of microstructural features and mechanical properties in the femoral head of patients with proximal femur fracture were thoroughly investigated at the tissue level.The results of this study will help to elucidate the mechanism of femoral head fracture for reducing fracture risk and developing treatment strategies for the elderly.
文摘In this paper, a new technique of capturing the images of debris inlubrication or hydraulic oil using micro-imaging and computer vision techniques is introduced. Byway of image processing, the size and distribution of debris are obtained, and then the oilcontamination level is also obtained. Because the information of oil contamination is obtaineddirectly from the images of debris by this method, the monitoring result is more intuitive andreliable.
文摘It has become general for surface waters being polluted by micro organic compounds. In order to know the current pollution situation and the properties of micro organic compounds in the Changjiang River, a test was performed on micro organic compounds in the water, bottom material and fish bodies which were sampled from major city river reaches of the Changjiang River. Based on the test result, researchers described and analyzed the sorts, concentration level and distribution features of micro organic compounds. A comprehensive evaluation was conducted by adopting the method of MEG (Multimedia Environmental Goals). The study indicated that ① the water body of major city river reaches of the Changjiang River has been generally polluted. In the test, totally 12 types with 308 kinds of organic compounds were detected. The main pollutants were paraffins, PAHs and lipids; and ② micro organic pollutant content in fish bodies was generally higher than that in bottom material which is in turn higher than that in water; and ③ pollution is relatively severe in the river reaches of mid-to-large comprehensive industrial cities with fairly great TAS (Total Ambient Severity) of public health and ecological system.
文摘For English education primary school,English vocabulary teaching should be attach importance to because in the traditional class of English vocabulary teaching,teachers just fill young minds with knowledge points of each word in a 35-minute class yet fail to lay emphasis of learners’meaningful learning and autonomic learning as well as their very limited attention spans.To support traditional English vocabulary teaching classes,the research proposes the theme-based English vocabulary micro-lectures designed on the basis of experiential learning theory and constructivist learning theory as well as the analyses of target users of high-level students in the primary school.After application of the micro-lectures into practice,the research assesses the effect of the micro-lectures on the learners and then makes suggestions for design principles of theme-based vocabulary micro-lectures about selection of contents and vocabulary themes,supplementary teaching activities and teacher interaction in the micro-lectures for high-level students in the primary school.Also,the designers should make multi-level English vocabulary micro-lectures according to learners’English proficiency and increase repetition rates of vocabularies in the micro-lectures.
