A novel aqueous route for the synthesis of high-quality CdTe nanocrystals（NCs） is presented in this article. With both glutathione（GSH） and cysteine[n（GSH）：n（cysteine）=1：3] as stabilizers, high-quality CdTe ...A novel aqueous route for the synthesis of high-quality CdTe nanocrystals（NCs） is presented in this article. With both glutathione（GSH） and cysteine[n（GSH）：n（cysteine）=1：3] as stabilizers, high-quality CdTe NCs with controllable photoluminescence（PL） wavelength from 500 to 630 nm can be prepared within 4 h. As-prepared CdTe NCs show higher photoluminescence quantum yields（PLQY） compared with CdTe NCs prepared via other aqueous methods. When the fluorescent emission peak appeared in orange-red window, the PLQY reaches 70% or above at room temperature without any post-preparative treatment.展开更多
由于T300与国产碳纤维的性能有很大差异,其中包括纤维本体的差异和涂层的差异。主要研究了两种纤维本体强度的差异。通过对两种纤维本体单丝拉伸强度的测试和W e ibu ll统计方法分析可知,国产碳纤维要比T300的单丝拉伸强度大,稳定性较好...由于T300与国产碳纤维的性能有很大差异,其中包括纤维本体的差异和涂层的差异。主要研究了两种纤维本体强度的差异。通过对两种纤维本体单丝拉伸强度的测试和W e ibu ll统计方法分析可知,国产碳纤维要比T300的单丝拉伸强度大,稳定性较好。X射线衍射(XRD)分析表明T300纤维微晶尺寸较小并且石墨化程度比国产碳纤维差。元素分析显示,T300中N元素含量超过国产碳纤维。结果表明,微晶尺寸和纤维中N元素含量是影响碳纤维强度的重要因素。展开更多
The surface composition and properties of the copolymer miniemulsions containing fluorinated acrylate(FA) were investigated by X-ray photoelectron spectroscopy(XPS) and contact angle measurements.The surface energy of...The surface composition and properties of the copolymer miniemulsions containing fluorinated acrylate(FA) were investigated by X-ray photoelectron spectroscopy(XPS) and contact angle measurements.The surface energy of these copolymers was calculated by the harmonic equation from the static contact angles.The surfaces of the copolymers are very hydrophobic even with a low content of FA due to the surface enrichment of FA segments.The surface energy of copolymers decreases drastically with the increase of FA content and can reach 11.6 mN/m when the concentration of FA in copolymerization increases to 17.54%.The element composition and surface segregation of the fluorinated component as a function of depth of fluorocopolymer thick films were investigated by angle-dependent XPS.The content of fluorine on the surface of copolymers was higher than the calculated value according to the feeds.Our analyses demonstrate that the side groups containing fluorine tend to enrich on the copolymer-air interface.The surface segregation is enhanced when the samples are annealed,which results in further decrease of surface energy.展开更多
基金National Key Technologies Research & Development Program of China(No.2006BAK03A09)National Basic Research Program of China(No.2007CB714503)Science and Technology Development Program of Jilin Pro- vince(No.20060706)
文摘A novel aqueous route for the synthesis of high-quality CdTe nanocrystals（NCs） is presented in this article. With both glutathione（GSH） and cysteine[n（GSH）：n（cysteine）=1：3] as stabilizers, high-quality CdTe NCs with controllable photoluminescence（PL） wavelength from 500 to 630 nm can be prepared within 4 h. As-prepared CdTe NCs show higher photoluminescence quantum yields（PLQY） compared with CdTe NCs prepared via other aqueous methods. When the fluorescent emission peak appeared in orange-red window, the PLQY reaches 70% or above at room temperature without any post-preparative treatment.
文摘由于T300与国产碳纤维的性能有很大差异,其中包括纤维本体的差异和涂层的差异。主要研究了两种纤维本体强度的差异。通过对两种纤维本体单丝拉伸强度的测试和W e ibu ll统计方法分析可知,国产碳纤维要比T300的单丝拉伸强度大,稳定性较好。X射线衍射(XRD)分析表明T300纤维微晶尺寸较小并且石墨化程度比国产碳纤维差。元素分析显示,T300中N元素含量超过国产碳纤维。结果表明,微晶尺寸和纤维中N元素含量是影响碳纤维强度的重要因素。
文摘The surface composition and properties of the copolymer miniemulsions containing fluorinated acrylate(FA) were investigated by X-ray photoelectron spectroscopy(XPS) and contact angle measurements.The surface energy of these copolymers was calculated by the harmonic equation from the static contact angles.The surfaces of the copolymers are very hydrophobic even with a low content of FA due to the surface enrichment of FA segments.The surface energy of copolymers decreases drastically with the increase of FA content and can reach 11.6 mN/m when the concentration of FA in copolymerization increases to 17.54%.The element composition and surface segregation of the fluorinated component as a function of depth of fluorocopolymer thick films were investigated by angle-dependent XPS.The content of fluorine on the surface of copolymers was higher than the calculated value according to the feeds.Our analyses demonstrate that the side groups containing fluorine tend to enrich on the copolymer-air interface.The surface segregation is enhanced when the samples are annealed,which results in further decrease of surface energy.
