This work mainly focuses on the mineralogical study of particulate matter（PM10） in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic m...This work mainly focuses on the mineralogical study of particulate matter（PM10） in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic microscopy coupled with energy dispersive X-ray（SEM/EDX） was used to investigate individual mineral particles in Beijing PM10. 1454 individual mineral particulates from 48 samples were analysed by SEM/EDX. The results revealed that mineral particulates were complex and heterogeneous. 38 kinds of minerals in PM10 were identified. The clay minerals, of annual average percentage of 30.1%, were the main composition among the identified minerals, and illite/smectite was the main composition in clay minerals, reaching up to 35%. Annual average percentage of quartz, calcite, compound particulates, carbonates were 13.5%, 10.9%, 11.95%, 10.31%, respectively. Annual average percentage less than 10% were gypsum, feldspar, dolomite, and so on. Fluorite, apatite, halite, barite and chloridize zinc（ZnCl2） were firstly identified in Beijing PM10. Sulfurization was found on surface of mineral particles, suggested extensive atmospheric reaction in air during summer.展开更多
A facile and general method was described to coat six types of multi-walled carbon nanotubes, functionalized by either noncovalent or covalent way, with smooth silica shells. 3-Aminopropyltriethoxysilane（APTES） and ...A facile and general method was described to coat six types of multi-walled carbon nanotubes, functionalized by either noncovalent or covalent way, with smooth silica shells. 3-Aminopropyltriethoxysilane（APTES） and pH value play important roles in the coating process and the thickness of silica shell could be controlled by the added amount of silicon alkoxides. After the removal of multi-walled carbon nanotubes by calcination, the silica nanotubes were successfully prepared.展开更多
Objective:Analyze the correlation between the bone mineral density value of army officers and soldiers and the fracture caused by military training,and construct the prediction model of the risk factors of the fractur...Objective:Analyze the correlation between the bone mineral density value of army officers and soldiers and the fracture caused by military training,and construct the prediction model of the risk factors of the fracture caused by military training.Methods:A total of 1019 officers and soldiers in a military training unit from January 2015 to November 2020 were selected and divided into groups according to whether they were fractured during military training.The basic data were collected in the form of a questionnaire,and the bone mineral density of the forearm and wrist of all subjects were measured by osteosys exa-3000 dual-energy X-ray absorptiometry in Korea.Pearson correlation analysis was used to analyze the correlation between bone mineral density and fractures caused by military training.Multivariate logistic regression was used to analyze the risk factors of fractures caused by military training,build a prediction model,and draw an ROC curve to verify its predictive value for fractures caused by military training.Results:There were statistically significant differences between patients with fractures caused by military training and those without fractures in previous fracture history,training period,self-evaluation of training intensity,the intensity of self-protection awareness,and bone mineral density(p<0.05);Multivariate logistic regression analysis showed that past fracture history,training intensity,injury subjects,self-protection awareness,and bone mineral density were all independent factors influencing fractures caused by military training(P<0.05);Pearson correlation analysis showed that bone mineral density was negatively correlated with fractures caused by military training(r=0.686,P<0.01);a predictive model was constructed,model1 was previous fracture history+training intensity+injury subjects+self-protection awareness,model 2 is the previous fracture history+training intensity+injury subjects+self-protection awareness+bone mineral density value.The area under the ROC curve of model 1 and model 2 were 0.729(0.648-0.785)and 0.893(0.837-0.914),respectively,and the Youde index were 0.415 and 0.682,respectively.Conclusion:There is a negative correlation between bone mineral density and fractures caused by military training.The prediction value of the fracture prediction model caused by military training constructed by the bone mineral density value is higher.展开更多
基金The National Natural Science Foundation of China（No.40275040） and the Shanghai Leading Academic Disciplines（No. T0105）
文摘This work mainly focuses on the mineralogical study of particulate matter（PM10） in Beijing. Samples were collected on polycarbonate filter from April, 2002 to March, 2003 in Beijing urban area. Scanning electronic microscopy coupled with energy dispersive X-ray（SEM/EDX） was used to investigate individual mineral particles in Beijing PM10. 1454 individual mineral particulates from 48 samples were analysed by SEM/EDX. The results revealed that mineral particulates were complex and heterogeneous. 38 kinds of minerals in PM10 were identified. The clay minerals, of annual average percentage of 30.1%, were the main composition among the identified minerals, and illite/smectite was the main composition in clay minerals, reaching up to 35%. Annual average percentage of quartz, calcite, compound particulates, carbonates were 13.5%, 10.9%, 11.95%, 10.31%, respectively. Annual average percentage less than 10% were gypsum, feldspar, dolomite, and so on. Fluorite, apatite, halite, barite and chloridize zinc（ZnCl2） were firstly identified in Beijing PM10. Sulfurization was found on surface of mineral particles, suggested extensive atmospheric reaction in air during summer.
基金Supported by the National Basic Research Program of China(No.2006CB705604)the National Natural Science Foundation of China(No.20907028)+4 种基金the Project of Science and Technology Commission of Shanghai MunicipalityChina(Nos.09XD1401800 09530501200)the Project of Shanghai Leading Academic Disciplines China(No.S30109)
文摘A facile and general method was described to coat six types of multi-walled carbon nanotubes, functionalized by either noncovalent or covalent way, with smooth silica shells. 3-Aminopropyltriethoxysilane（APTES） and pH value play important roles in the coating process and the thickness of silica shell could be controlled by the added amount of silicon alkoxides. After the removal of multi-walled carbon nanotubes by calcination, the silica nanotubes were successfully prepared.
文摘Objective:Analyze the correlation between the bone mineral density value of army officers and soldiers and the fracture caused by military training,and construct the prediction model of the risk factors of the fracture caused by military training.Methods:A total of 1019 officers and soldiers in a military training unit from January 2015 to November 2020 were selected and divided into groups according to whether they were fractured during military training.The basic data were collected in the form of a questionnaire,and the bone mineral density of the forearm and wrist of all subjects were measured by osteosys exa-3000 dual-energy X-ray absorptiometry in Korea.Pearson correlation analysis was used to analyze the correlation between bone mineral density and fractures caused by military training.Multivariate logistic regression was used to analyze the risk factors of fractures caused by military training,build a prediction model,and draw an ROC curve to verify its predictive value for fractures caused by military training.Results:There were statistically significant differences between patients with fractures caused by military training and those without fractures in previous fracture history,training period,self-evaluation of training intensity,the intensity of self-protection awareness,and bone mineral density(p<0.05);Multivariate logistic regression analysis showed that past fracture history,training intensity,injury subjects,self-protection awareness,and bone mineral density were all independent factors influencing fractures caused by military training(P<0.05);Pearson correlation analysis showed that bone mineral density was negatively correlated with fractures caused by military training(r=0.686,P<0.01);a predictive model was constructed,model1 was previous fracture history+training intensity+injury subjects+self-protection awareness,model 2 is the previous fracture history+training intensity+injury subjects+self-protection awareness+bone mineral density value.The area under the ROC curve of model 1 and model 2 were 0.729(0.648-0.785)and 0.893(0.837-0.914),respectively,and the Youde index were 0.415 and 0.682,respectively.Conclusion:There is a negative correlation between bone mineral density and fractures caused by military training.The prediction value of the fracture prediction model caused by military training constructed by the bone mineral density value is higher.
