High-purity SiO_(2)nanoparticles(SNPs)play a crucial role in various electronic applications,such as semiconductors,solar cells,optical fibers,lenses,and insulating layers,given their purity and particle size,which si...High-purity SiO_(2)nanoparticles(SNPs)play a crucial role in various electronic applications,such as semiconductors,solar cells,optical fibers,lenses,and insulating layers,given their purity and particle size,which significantly impact device efficiency.This study fo-cuses on the synthesis and characterization of pure SNPs through the chemical etching of greater club rush.White powder SNPs were pre-pared using HCl etching,and their thermal behaviors were analyzed via thermogravimetric analysis/differential scanning calorimetry.Structural properties were investigated using X-ray fluorescence,scanning electron microscopy,and transmission electron microscopy.X-ray absorption near-edge structure was employed to assess the oxidation state of the SNPs.The morphology of the SNPs after the first etching was amorphous,with sizes ranging from 50 to 100 nm,which increased to 50-200 nm after the second etching.Despite this size variation,the SNPs maintained a high purity level of 99.8wt%SiO_(2),comparable with industry standards.Notably,the second etching with 0.1-M HCl significantly enhanced the purity level,achieving 99.8wt%SiO_(2)mass.Furthermore,HCl etching facilitated the formation of SiO_(2)in the Si^(4+)oxidation state,akin to industrial SNPs.These findings underscore the critical role of HCl etching in synthesizing high-purity SNPs,with potential applications in advanced electronic devices.展开更多
目的了解年轻男男性行为者(young men who have sex with men,YMSM)rush poppers(以下简称rush)使用现状,分析影响因素。方法 2016年9月—2019年9月,用"滚雪球"抽样法,在绵阳市进行YMSM rush使用和血清学的现况调查,用χ^(2)...目的了解年轻男男性行为者(young men who have sex with men,YMSM)rush poppers(以下简称rush)使用现状,分析影响因素。方法 2016年9月—2019年9月,用"滚雪球"抽样法,在绵阳市进行YMSM rush使用和血清学的现况调查,用χ^(2)检验,logistics回归分析rush使用的影响因素。结果 336名YMSM的rush使用率24.1%,使用时间中位数为4.5(2.0,12.0)个月,42.0%因好奇、29.6%因减少肛交疼痛、27.2%因寻求刺激使用,81.5%与固定性伴、28.4%与偶遇性伴共用,使用后30.8%发生无保护肛交。rush使用的HIV-1阳性率12.3%,高于未使用的2.0%(χ^(2)=15.544,P<0.001)。多因素分析发现,职业非学生(OR=1.992,95%CI:1.036~3.831)、知晓艾滋病知识(OR=2.617,95%CI:1.235~5.545)、有风险认识(OR=4.407,95%CI:1.220~15.918)、近6个月有商业性行为(OR=9.136,95%CI:1.228~67.985)、近6个月肛交人数增加(OR=1.732,95%CI:1.170~2.563)的rush使用可能更大,近1年接受宣传材料发放(OR=0.410,95%CI:0.203~0.825)、近1次肛交有保护(OR=0.346,95%CI:0.152~0.785)的rush使用可能更小。结论 YMSM其rush使用较普遍,好奇是主要原因,与固定性伴共用常见。rush使用增加其高危性行为和HIV感染风险,应针对性加强健康教育。展开更多
基金supported by the Suranaree University of Technology(SUT)Center of Excellence(CoE)on Advanced Functional Materials(AFM),School of Physics,Suranaree University of Technology,Nakhon Ratchasima,Thailand,the External Grants and Scholarships for Graduate Students,Suranaree University of Technology,Nakhon Ratchasima,Thailand,and the Research Network on Nanotechnology(RNN),Suranaree University of Technology,Nakhon Ratchasima,Thailand.
文摘High-purity SiO_(2)nanoparticles(SNPs)play a crucial role in various electronic applications,such as semiconductors,solar cells,optical fibers,lenses,and insulating layers,given their purity and particle size,which significantly impact device efficiency.This study fo-cuses on the synthesis and characterization of pure SNPs through the chemical etching of greater club rush.White powder SNPs were pre-pared using HCl etching,and their thermal behaviors were analyzed via thermogravimetric analysis/differential scanning calorimetry.Structural properties were investigated using X-ray fluorescence,scanning electron microscopy,and transmission electron microscopy.X-ray absorption near-edge structure was employed to assess the oxidation state of the SNPs.The morphology of the SNPs after the first etching was amorphous,with sizes ranging from 50 to 100 nm,which increased to 50-200 nm after the second etching.Despite this size variation,the SNPs maintained a high purity level of 99.8wt%SiO_(2),comparable with industry standards.Notably,the second etching with 0.1-M HCl significantly enhanced the purity level,achieving 99.8wt%SiO_(2)mass.Furthermore,HCl etching facilitated the formation of SiO_(2)in the Si^(4+)oxidation state,akin to industrial SNPs.These findings underscore the critical role of HCl etching in synthesizing high-purity SNPs,with potential applications in advanced electronic devices.
文摘目的了解年轻男男性行为者(young men who have sex with men,YMSM)rush poppers(以下简称rush)使用现状,分析影响因素。方法 2016年9月—2019年9月,用"滚雪球"抽样法,在绵阳市进行YMSM rush使用和血清学的现况调查,用χ^(2)检验,logistics回归分析rush使用的影响因素。结果 336名YMSM的rush使用率24.1%,使用时间中位数为4.5(2.0,12.0)个月,42.0%因好奇、29.6%因减少肛交疼痛、27.2%因寻求刺激使用,81.5%与固定性伴、28.4%与偶遇性伴共用,使用后30.8%发生无保护肛交。rush使用的HIV-1阳性率12.3%,高于未使用的2.0%(χ^(2)=15.544,P<0.001)。多因素分析发现,职业非学生(OR=1.992,95%CI:1.036~3.831)、知晓艾滋病知识(OR=2.617,95%CI:1.235~5.545)、有风险认识(OR=4.407,95%CI:1.220~15.918)、近6个月有商业性行为(OR=9.136,95%CI:1.228~67.985)、近6个月肛交人数增加(OR=1.732,95%CI:1.170~2.563)的rush使用可能更大,近1年接受宣传材料发放(OR=0.410,95%CI:0.203~0.825)、近1次肛交有保护(OR=0.346,95%CI:0.152~0.785)的rush使用可能更小。结论 YMSM其rush使用较普遍,好奇是主要原因,与固定性伴共用常见。rush使用增加其高危性行为和HIV感染风险,应针对性加强健康教育。
