A microscopic high spin study of neutron deficient and normally deformed 133,135,137Sm has been carried out in projected shell model framework.The theoretical results have been obtained for the spins,parities and ener...A microscopic high spin study of neutron deficient and normally deformed 133,135,137Sm has been carried out in projected shell model framework.The theoretical results have been obtained for the spins,parities and energy values of yrast and excited bands.Besides this,the band spectra,band head energies,moment of inertia and electromagnetic transition strengths are also Predicted in these isotoPes.The calculations successfully give a deeper understanding of the mechanism of the formation of yrast and excited bands from the single and multi-quasi particle configurations.The results on moment of inertia predict an alignment of a pair of protons in the proton(1 h11/2)^2 orbitals in the yrast ground state bands of 133-137Sm due to the crossing of one quasiparticle bands by multi-quasiparticle bands at higher spins.The discussion in the present work is based on the deformed single particle scheme.Any future experimental confirmation or refutation of our predictions will be a valuable information which can help to understand the deformed single particle structure in these odd mass neutron deficient 133-137Sm.展开更多
加权修正的差分光学吸收光谱法(weighting function modified differential optical absorption spectroscopy,WFM-DOAS)是用于甲烷平均干空气摩尔分数(XCH4)遥感反演的经典算法,其关键技术之一是分离“宽带吸收”与“窄带吸收”光谱结...加权修正的差分光学吸收光谱法(weighting function modified differential optical absorption spectroscopy,WFM-DOAS)是用于甲烷平均干空气摩尔分数(XCH4)遥感反演的经典算法,其关键技术之一是分离“宽带吸收”与“窄带吸收”光谱结构;同时,数字高程模型(digital elevation model,DEM)对XCH4的反演有重要影响。目前已有的甲烷反演产品主要使用多项式进行宽带结构拟合,多项式阶数的选择标准不明确、对宽带结构的拟合不够精确,使用的DEM精度无法满足局部地区高精度反演要求。本文选取瓦里关大气本底基准观象台所在的青藏高原区域为研究区,使用更高精度的数字高程模型(global 30 m digital elevation model,GLO-30)并用全连接神经网络代替低阶多项式进行“宽带结构”拟合,进一步地,在传统的全连接神经网络的基础上加入了“跳连”结构,并使用dropout策略对网络进行优化。将实验结果与使用The Global Multi-resolution Terrain Elevation Data 2010(GMTED2010)和低阶多项式拟合方法下反演的XCH4进行数据对比。结果显示,改进后的全连接神经网络可以更好地拟合宽带光谱结构,同时联合更高精度的DEM可以提高XCH4的反演精度,相关系数最高提高到0.92。所使用的联合优化方法可以用于油气田产区的XCH4的遥感反演,从而更好地服务于油气田产区甲烷异常排放排查等。展开更多
XPS technique has been used extensively in the studies of electronic structure on the complexes, and the bonding characteristics between the complex ions have also been explored. XPS investigations on transition metal...XPS technique has been used extensively in the studies of electronic structure on the complexes, and the bonding characteristics between the complex ions have also been explored. XPS investigations on transition metal complexes and the studies on RE oxides and halides have been reported. But XPS studies on RE complexes are nearly nil. The XPS studies展开更多
A polycrystalline dense Ti3SiC2 based ceramic material has been produced by several techniques. The effect of addition of TiC and SiC is also studied. The Ti3SiC2 material shows extraordinary electrical, thermal and m...A polycrystalline dense Ti3SiC2 based ceramic material has been produced by several techniques. The effect of addition of TiC and SiC is also studied. The Ti3SiC2 material shows extraordinary electrical, thermal and mechanical properties. Furthermore, it shows a damage tolerance capability and oxidation resistance. In this work, we have synthesized Ti3SiC2 by electro-thermal explosion chemical reaction (ETE) with high current density (900 Amperes/a.u) followed by uniaxial pressure. The structural properties of the as-prepared materials are studied by x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX) techniques. The chemical cartography, imaging and electronic properties are investigated using Ultra-STEM and electron high energy loss resolution spectroscopy (EELS) techniques, respectively. The surface of Ti3SiC2 is characterized by means of X-ray photoelectron spectroscopy (XPS). High resolution C 1s, Si 2p, Ti 2p, Ti 3s core level spectra are explained in terms of crystallographic and electronic structure. Valence band spectrum is performed to confirm the validity of the theoretical calculations.展开更多
A simple polyol and sol–gel Stober process were employed for synthesis of YF_3：Tb~＋（core）, YF_3：Tb~＋@LaF_3（core/shell） and YF_3：Tb~＋@LaF_3@SiO_2（core/shell/SiO_2） nanoparticles（NPs）. The phase purity, c...A simple polyol and sol–gel Stober process were employed for synthesis of YF_3：Tb~＋（core）, YF_3：Tb~＋@LaF_3（core/shell） and YF_3：Tb~＋@LaF_3@SiO_2（core/shell/SiO_2） nanoparticles（NPs）. The phase purity, crystalinity,morphology, optical and photoluminescence properties were investigated and discussed with the help of various analytical techniques including X-ray diffraction pattern,FE-transmission electron microscopy（TEM）,FTIR, UV/vis absorption, energy band gap and emission spectra. XRD andFE-TEM studies indicate the formation of core/shell nanostructure and ~10 nm thick amorphous silica surface coating surrounding the core-NPs, which is also confirmed byFTIR spectral results. The surface modifications of core-NPs significantly affect the optical features in the form of energy band gap, which were correlated with particle size of the nanomaterials. The comparative emission spectral results show that after inert layer coating the luminescent core-NPs display stronger emission intensity in respect to core and silica coated core/shell/SiO_2-NPs. The solubility character along with colloidal stability was improved after silica surface modification, whereas luminescent intensity was suppressed causing the surface functionalized with high energy silanol（Si-OH） molecules. These novel luminescent nanomaterials with enhanced emission intensity and excellent solubility in aqueous solvents would be potentially useful for fluorescence bioimaging/optical bio-probe etc.展开更多
文摘A microscopic high spin study of neutron deficient and normally deformed 133,135,137Sm has been carried out in projected shell model framework.The theoretical results have been obtained for the spins,parities and energy values of yrast and excited bands.Besides this,the band spectra,band head energies,moment of inertia and electromagnetic transition strengths are also Predicted in these isotoPes.The calculations successfully give a deeper understanding of the mechanism of the formation of yrast and excited bands from the single and multi-quasi particle configurations.The results on moment of inertia predict an alignment of a pair of protons in the proton(1 h11/2)^2 orbitals in the yrast ground state bands of 133-137Sm due to the crossing of one quasiparticle bands by multi-quasiparticle bands at higher spins.The discussion in the present work is based on the deformed single particle scheme.Any future experimental confirmation or refutation of our predictions will be a valuable information which can help to understand the deformed single particle structure in these odd mass neutron deficient 133-137Sm.
文摘加权修正的差分光学吸收光谱法(weighting function modified differential optical absorption spectroscopy,WFM-DOAS)是用于甲烷平均干空气摩尔分数(XCH4)遥感反演的经典算法,其关键技术之一是分离“宽带吸收”与“窄带吸收”光谱结构;同时,数字高程模型(digital elevation model,DEM)对XCH4的反演有重要影响。目前已有的甲烷反演产品主要使用多项式进行宽带结构拟合,多项式阶数的选择标准不明确、对宽带结构的拟合不够精确,使用的DEM精度无法满足局部地区高精度反演要求。本文选取瓦里关大气本底基准观象台所在的青藏高原区域为研究区,使用更高精度的数字高程模型(global 30 m digital elevation model,GLO-30)并用全连接神经网络代替低阶多项式进行“宽带结构”拟合,进一步地,在传统的全连接神经网络的基础上加入了“跳连”结构,并使用dropout策略对网络进行优化。将实验结果与使用The Global Multi-resolution Terrain Elevation Data 2010(GMTED2010)和低阶多项式拟合方法下反演的XCH4进行数据对比。结果显示,改进后的全连接神经网络可以更好地拟合宽带光谱结构,同时联合更高精度的DEM可以提高XCH4的反演精度,相关系数最高提高到0.92。所使用的联合优化方法可以用于油气田产区的XCH4的遥感反演,从而更好地服务于油气田产区甲烷异常排放排查等。
文摘XPS technique has been used extensively in the studies of electronic structure on the complexes, and the bonding characteristics between the complex ions have also been explored. XPS investigations on transition metal complexes and the studies on RE oxides and halides have been reported. But XPS studies on RE complexes are nearly nil. The XPS studies
文摘A polycrystalline dense Ti3SiC2 based ceramic material has been produced by several techniques. The effect of addition of TiC and SiC is also studied. The Ti3SiC2 material shows extraordinary electrical, thermal and mechanical properties. Furthermore, it shows a damage tolerance capability and oxidation resistance. In this work, we have synthesized Ti3SiC2 by electro-thermal explosion chemical reaction (ETE) with high current density (900 Amperes/a.u) followed by uniaxial pressure. The structural properties of the as-prepared materials are studied by x-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDX) techniques. The chemical cartography, imaging and electronic properties are investigated using Ultra-STEM and electron high energy loss resolution spectroscopy (EELS) techniques, respectively. The surface of Ti3SiC2 is characterized by means of X-ray photoelectron spectroscopy (XPS). High resolution C 1s, Si 2p, Ti 2p, Ti 3s core level spectra are explained in terms of crystallographic and electronic structure. Valence band spectrum is performed to confirm the validity of the theoretical calculations.
基金funded byNational Plan for Science,Technology and Innovation(MAARIFAH)King Abdulaziz City for Science and Technology,Kingdom of Saudi Arabia,award number(No.13-Bio1246-02)
文摘A simple polyol and sol–gel Stober process were employed for synthesis of YF_3：Tb~＋（core）, YF_3：Tb~＋@LaF_3（core/shell） and YF_3：Tb~＋@LaF_3@SiO_2（core/shell/SiO_2） nanoparticles（NPs）. The phase purity, crystalinity,morphology, optical and photoluminescence properties were investigated and discussed with the help of various analytical techniques including X-ray diffraction pattern,FE-transmission electron microscopy（TEM）,FTIR, UV/vis absorption, energy band gap and emission spectra. XRD andFE-TEM studies indicate the formation of core/shell nanostructure and ~10 nm thick amorphous silica surface coating surrounding the core-NPs, which is also confirmed byFTIR spectral results. The surface modifications of core-NPs significantly affect the optical features in the form of energy band gap, which were correlated with particle size of the nanomaterials. The comparative emission spectral results show that after inert layer coating the luminescent core-NPs display stronger emission intensity in respect to core and silica coated core/shell/SiO_2-NPs. The solubility character along with colloidal stability was improved after silica surface modification, whereas luminescent intensity was suppressed causing the surface functionalized with high energy silanol（Si-OH） molecules. These novel luminescent nanomaterials with enhanced emission intensity and excellent solubility in aqueous solvents would be potentially useful for fluorescence bioimaging/optical bio-probe etc.
