SiO_2/TiO_2/methylcellulose composite materials processed by the sol-gel technique were studied for optical waveguide applications. With the help of methylcellulose, an organic binder, SiO2/TiO2/methylcellulose hybrid...SiO_2/TiO_2/methylcellulose composite materials processed by the sol-gel technique were studied for optical waveguide applications. With the help of methylcellulose, an organic binder, SiO2/TiO2/methylcellulose hybrid thick films were prepared by a single spin-coating processes. After annealing at 70 °C for an hour, 2.5-μm crack-free and dense organic-inorganic hybrid optical films with a refractive index of 1.537 were achieved. Optical losses of plane waveguide made up of those films and ordinary slide glass substrate are around 0.3 dB/cm at 650 nm. Scanning electronmicroscopy (SEM) and UV-visible spectroscopy (UV-VIS), have been used to characterize the thick films.展开更多
利用高速电弧喷涂系统制备了FeBSiNb系铁基非晶厚涂层,采用扫描电子显微镜(Scanning Electron Microscope,SEM)、X射线衍射仪(X-Ray Diffraction,XRD)、透射电子显微镜(Transmission Electron Microscopy,TEM)、显微硬度计及万能拉伸试...利用高速电弧喷涂系统制备了FeBSiNb系铁基非晶厚涂层,采用扫描电子显微镜(Scanning Electron Microscope,SEM)、X射线衍射仪(X-Ray Diffraction,XRD)、透射电子显微镜(Transmission Electron Microscopy,TEM)、显微硬度计及万能拉伸试验机,分别对涂层的截面形貌、组织结构、显微硬度及拉伸应力应变进行了表征。结果表明:涂层厚度可达20 mm;涂层组织结构均匀致密,孔隙率在2.5%左右;涂层主要由非晶相及α-Fe相组成,其中非晶含量约为60%;与现有的FeBSiNb系非晶涂层相比,涂层平均显微硬度有所降低,约为826.8 HV0.1,拉伸断裂强度也有所降低,为211 MPa,而弹性应变有所提高,为0.69%。展开更多
Objective:To analyze the characteristics of bacterial flora on the tongue and types of tongue coating between healthy individuals and patients with type 2 diabetes mellitus(T2DM)via detecting 16S rDNA of oral tongue c...Objective:To analyze the characteristics of bacterial flora on the tongue and types of tongue coating between healthy individuals and patients with type 2 diabetes mellitus(T2DM)via detecting 16S rDNA of oral tongue coating microbial group.Methods:A total of 42 patients with T2DM were recruited,including 6 with thin white coating,9 with mirror-like coating,27 with yellow thick coating(YTC),and 28 healthy individuals.The V4 region of 16S rDNA from the tongue coating microbiota was sequenced using the Linux ubuntu sequencing platform,and the structure of bacterial flora in the tongue was analyzed.Treeplot construction,principal coordinates analysis,redundancy analysis,and linear discriminant analysis were conducted using R software to analyze the differences of bacterial flora in the tongue coating in each group.Results:A total of 8131 different operational taxonomic units(OTUs)were obtained via sequencing,of which 719 OTU samples showed significant differences(P<0.05).Comparing OTUs with the 16S rDNA database of known species and annotation of parallel species revealed 16 species with differences at the phylum level,31 at the class level,54 at the order level,88 at the family level,and 161 at the genus level.The dominant bacteria found in patients with T2DM included Lactobacillus,Streptophyta,Chloroplast,Cyanobacteria-Chloroplast,and Bifidobacteriaceae,etc.Dominant bacteria in the control group belonged to Pasteurellales,Pasteurellaceae,Leptotrichiaceae,Lachnoanaerobaculum,and Ignavibacteria among other bacterial families.All samples were clustered into three groups,each group characterized by dominant bacteria.The order of dominant bacteria in group 1 were Prevotella>Neisseria>Veillonella>Streptococcus>Fusobacterium>Leptotrichia and so on.The order of dominant bacteria of group 2 were Neisseria>Prevotella>Fusobacterium>Streptococcus>porphyromonas and so on.The dominant bacteria of group 3 were Prevotella>Fusobacterium>Streptococcus>Neisseria>Leptotrichia>Rothia>Veillonella>porphyromonas>f_Pasteurellaceae>Capnocyt展开更多
基金This work was supported by the National Natu- ral Science Foundation of China (No. 90206002 and 90201013)the National "863" Project of China (No. 2002AA313030).
文摘SiO_2/TiO_2/methylcellulose composite materials processed by the sol-gel technique were studied for optical waveguide applications. With the help of methylcellulose, an organic binder, SiO2/TiO2/methylcellulose hybrid thick films were prepared by a single spin-coating processes. After annealing at 70 °C for an hour, 2.5-μm crack-free and dense organic-inorganic hybrid optical films with a refractive index of 1.537 were achieved. Optical losses of plane waveguide made up of those films and ordinary slide glass substrate are around 0.3 dB/cm at 650 nm. Scanning electronmicroscopy (SEM) and UV-visible spectroscopy (UV-VIS), have been used to characterize the thick films.
文摘利用高速电弧喷涂系统制备了FeBSiNb系铁基非晶厚涂层,采用扫描电子显微镜(Scanning Electron Microscope,SEM)、X射线衍射仪(X-Ray Diffraction,XRD)、透射电子显微镜(Transmission Electron Microscopy,TEM)、显微硬度计及万能拉伸试验机,分别对涂层的截面形貌、组织结构、显微硬度及拉伸应力应变进行了表征。结果表明:涂层厚度可达20 mm;涂层组织结构均匀致密,孔隙率在2.5%左右;涂层主要由非晶相及α-Fe相组成,其中非晶含量约为60%;与现有的FeBSiNb系非晶涂层相比,涂层平均显微硬度有所降低,约为826.8 HV0.1,拉伸断裂强度也有所降低,为211 MPa,而弹性应变有所提高,为0.69%。
文摘Objective:To analyze the characteristics of bacterial flora on the tongue and types of tongue coating between healthy individuals and patients with type 2 diabetes mellitus(T2DM)via detecting 16S rDNA of oral tongue coating microbial group.Methods:A total of 42 patients with T2DM were recruited,including 6 with thin white coating,9 with mirror-like coating,27 with yellow thick coating(YTC),and 28 healthy individuals.The V4 region of 16S rDNA from the tongue coating microbiota was sequenced using the Linux ubuntu sequencing platform,and the structure of bacterial flora in the tongue was analyzed.Treeplot construction,principal coordinates analysis,redundancy analysis,and linear discriminant analysis were conducted using R software to analyze the differences of bacterial flora in the tongue coating in each group.Results:A total of 8131 different operational taxonomic units(OTUs)were obtained via sequencing,of which 719 OTU samples showed significant differences(P<0.05).Comparing OTUs with the 16S rDNA database of known species and annotation of parallel species revealed 16 species with differences at the phylum level,31 at the class level,54 at the order level,88 at the family level,and 161 at the genus level.The dominant bacteria found in patients with T2DM included Lactobacillus,Streptophyta,Chloroplast,Cyanobacteria-Chloroplast,and Bifidobacteriaceae,etc.Dominant bacteria in the control group belonged to Pasteurellales,Pasteurellaceae,Leptotrichiaceae,Lachnoanaerobaculum,and Ignavibacteria among other bacterial families.All samples were clustered into three groups,each group characterized by dominant bacteria.The order of dominant bacteria in group 1 were Prevotella>Neisseria>Veillonella>Streptococcus>Fusobacterium>Leptotrichia and so on.The order of dominant bacteria of group 2 were Neisseria>Prevotella>Fusobacterium>Streptococcus>porphyromonas and so on.The dominant bacteria of group 3 were Prevotella>Fusobacterium>Streptococcus>Neisseria>Leptotrichia>Rothia>Veillonella>porphyromonas>f_Pasteurellaceae>Capnocyt
