On the basis of the obtained intensity parameters Ω λ(λ =2,4,6) of Tm 3+ in the Na 5Tm(WO 4) 4 crystal, we performed calculations on the radiative transition probability, radiative lifetime, branching ...On the basis of the obtained intensity parameters Ω λ(λ =2,4,6) of Tm 3+ in the Na 5Tm(WO 4) 4 crystal, we performed calculations on the radiative transition probability, radiative lifetime, branching ratios and stimulated emission integrated cross sections between the two excited J manifolds of Tm 3+ , and discussed potentiality for the usage of this crystal as a laser material.展开更多
A d-f heteronuclear metal-organic framework（MOF）,{[Tm3Zn6（bipy2）2（mimda）7（H2O）3]·（H2O）5}n（1,H3 mimda = 2-methyl-1-H-imidazole-4,5-dicarboxylic acid,and bipy = 4,4？-bipyridine）,has been synthesized un...A d-f heteronuclear metal-organic framework（MOF）,{[Tm3Zn6（bipy2）2（mimda）7（H2O）3]·（H2O）5}n（1,H3 mimda = 2-methyl-1-H-imidazole-4,5-dicarboxylic acid,and bipy = 4,4？-bipyridine）,has been synthesized under solvothermal conditions,and structurally characterized by elemental analysis,IR spectra and X-ray single-crystal diffraction.It crystallizes in orthorhombic system,space group Pnma with a = 16.1102（9）,b = 33.5805（19）,c = 16.8593（10） ？,β = 97.344（11）°,V = 9120.7（9） ？-3,Z = 4,F（000） = 5184,the final R = 0.0530 and w R = 0.1306.In complex 1,the Tm（Ⅲ） ions adopt two types of coordination fashions.Complex 1 shows onedimensional（1-D） Tm-Zn heteronuclear zigzag chains,and these chains are further linked by H3 mimda ligands into Tm-Zn heteronuclear 2-D lattice-like arrays.The 2-D heteronuclear units were connected through [Zn6（mimda）6] rings to give rise to the Tm-Zn heteronuclear cages.Finally,H3 mimda ligands connected the cages into a 3-D heterometallic framework by the combination of [TmO7]n and Tm-Zn heteronuclear cages.In addition,the thermal stability and luminescent property have been investigated.展开更多
A diode-pumped continuous-wave Tm:YVO_[4]laser operating on the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions was demonstrated for the first time,to the best of our knowledge.An a-cut Tm:YVO_[4]crystal with 1.5%[ato...A diode-pumped continuous-wave Tm:YVO_[4]laser operating on the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions was demonstrated for the first time,to the best of our knowledge.An a-cut Tm:YVO_[4]crystal with 1.5%[atomic fraction]Tm3+ion concentration was used to characterize the laser behavior.A common commercial laser diode with a central wavelength of 790 nm and a bandwidth of 3.2 nm was utilized as a pump source.With an output coupler for the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions,simultaneous three-wavelength laser operation was achieved.The laser emissions at 2292 and 2363 nm inπ-polarization and at 2108 nm inσ-polarization were realized.With an incident pump power of 22 W,the total output power of 1.17 W at 2292,2363,and 2108 nm was obtained.The output power at 2292 and 2363 nm was measured to be 750 mW,and the output power at 2108 nm was measured to be 420 mW.展开更多
目的探讨跨膜蛋白4超级家族5（transmembrane 4 superfamily member 5,TM4SF5）基因多态性、栽脂蛋白E（ApoE）基因多态性和阿尔茨海默病（AD）的相关性。方法通过使用TaqMan—PCR法检测单核苷酸多态性（SNP）方法，在376例日本人AD患...目的探讨跨膜蛋白4超级家族5（transmembrane 4 superfamily member 5,TM4SF5）基因多态性、栽脂蛋白E（ApoE）基因多态性和阿尔茨海默病（AD）的相关性。方法通过使用TaqMan—PCR法检测单核苷酸多态性（SNP）方法，在376例日本人AD患者，包括323例迟发型AD（I。OAD）、53例早发型AD（EOAD）和377例非痴呆对照组中观察TM4SF5基因rs4790230（-791T／C）、rs746988（＋1528T／c）、rs2302328（＋11228c／A）及APOE基因的多态性分布，并分析与AD的相关性。结果（1）TM4SF5基因rs4790230（-791T／C）c／c纯合子频率在EOAD中明显高于对照组（0．70比0．52，P值为0．017）；rs2302328（＋11228C／A）携带A等位基因者频率在总AD中略高于对照组（0．88比0．84，P值为0．05）；（2）进一步在非APOE4携带者中分析显示rs4790230（-791T／C）c／c纯合子频率在EOAD中仍明显高于对照组（0．85比0．53，P〈0．001）；（3）单倍型分析显示病例组C—C—A型与C—T—A型频率分别高于时照组（0．29比0．21；0．35比0．16；P〈0．001）；病例组C—T—C型频率低于对照组（0．12比0．28；P〈0．001）。结论TM4SF5基因rs4790230（-791T／C）多态位点独立于APOE与EOAD存在相关性，三位点单倍型C—C—A型与C—T—A型增加了AD的发病风险。展开更多
Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to...Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to4I15/2 →4I13/2,4I13/2 →4I11/2,and4I11/2 →4I9/2 transitions,respectively,are observed.LiYF4 single crystals possess high transmittance of over 85% in the 2.5-6 μm range.The large emission crosssections of Tm-doped crystals at 2.4 μm（1.9×10-20cm2） and Nd-doped crystals at 4.2 μm（0.84×10-20 cm2） as well as the high rare-earth doping concentrations,excellent optical transmission,and chemicalphysical properties of the resultant samples indicate that Nd3＋and Tm3＋singly doped crystals may be promising materials for application in MIR lasers.展开更多
This study evaluates the long-term radiometric performance of the USGS new released Landsat Collection 1 archive, including the absolute calibration of each Landsat sensor as well as the relative cross-calibration amo...This study evaluates the long-term radiometric performance of the USGS new released Landsat Collection 1 archive, including the absolute calibration of each Landsat sensor as well as the relative cross-calibration among the four most popular Landsat sensors. A total of 920 Landsat Collection 1 scenes were evaluated against the corresponding Pre-Collection images over a Pseudo-Invariant Site, Railroad Valley Playa Nevada, United States (RVPN). The radiometric performance of the six Landsat solar reflective bands, in terms of both Digital Numbers (DNs) and at-sensor Top of Atmosphere (TOA) reflectance, on the sensor cross-calibration was examined. Results show that absolute radiometric calibration at DNs level was applied to the Landsat-4 and -5 TM (L4 TM and L5 TM) by –1.119% to 0.126%. For L4 TM and L5 TM, the cross-calibration decreased the radiometric measurement level by rescaling at-sensor radiance to DN values. The radiometric changes, –0.77% for L4 TM, 0.95% for L5 TM, –0.26% for L7 ETM+, and –0.01% for L8 OLI, were detected during the cross-calibration stage of converting DNs into TOA reflectance. This study has also indicated that the long-term radiometric performance for the Landsat Collection 1 archive is promising. Supports of these conclusions were demonstrated through the time-series analysis based on the Landsat Collection 1 image stack. Nevertheless, the radiometric changes across the four Landsat sensors raised concerns of the previous Landsat Pre-Collection based results. We suggest that Landsat users should pay attention to differences in results from Pre-Collection and Collection 1 time-series data sets.展开更多
文摘On the basis of the obtained intensity parameters Ω λ(λ =2,4,6) of Tm 3+ in the Na 5Tm(WO 4) 4 crystal, we performed calculations on the radiative transition probability, radiative lifetime, branching ratios and stimulated emission integrated cross sections between the two excited J manifolds of Tm 3+ , and discussed potentiality for the usage of this crystal as a laser material.
基金Supported by the Foundation for Science&Technology Innovation Talents in Henan Province(Nos.14HASTIT014,and 16410010012)Natural Science Foundation of China(Nos.21671114)the Foundation of Education Committee of Henan province,China(No.14B150033)
文摘A d-f heteronuclear metal-organic framework（MOF）,{[Tm3Zn6（bipy2）2（mimda）7（H2O）3]·（H2O）5}n（1,H3 mimda = 2-methyl-1-H-imidazole-4,5-dicarboxylic acid,and bipy = 4,4？-bipyridine）,has been synthesized under solvothermal conditions,and structurally characterized by elemental analysis,IR spectra and X-ray single-crystal diffraction.It crystallizes in orthorhombic system,space group Pnma with a = 16.1102（9）,b = 33.5805（19）,c = 16.8593（10） ？,β = 97.344（11）°,V = 9120.7（9） ？-3,Z = 4,F（000） = 5184,the final R = 0.0530 and w R = 0.1306.In complex 1,the Tm（Ⅲ） ions adopt two types of coordination fashions.Complex 1 shows onedimensional（1-D） Tm-Zn heteronuclear zigzag chains,and these chains are further linked by H3 mimda ligands into Tm-Zn heteronuclear 2-D lattice-like arrays.The 2-D heteronuclear units were connected through [Zn6（mimda）6] rings to give rise to the Tm-Zn heteronuclear cages.Finally,H3 mimda ligands connected the cages into a 3-D heterometallic framework by the combination of [TmO7]n and Tm-Zn heteronuclear cages.In addition,the thermal stability and luminescent property have been investigated.
基金supported by the Fundamental Research Funds for the Central Universities and the National Natural Science Foundation of China(No.61378027)。
文摘A diode-pumped continuous-wave Tm:YVO_[4]laser operating on the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions was demonstrated for the first time,to the best of our knowledge.An a-cut Tm:YVO_[4]crystal with 1.5%[atomic fraction]Tm3+ion concentration was used to characterize the laser behavior.A common commercial laser diode with a central wavelength of 790 nm and a bandwidth of 3.2 nm was utilized as a pump source.With an output coupler for the^[3]H_[4]→^[3]H_[5]and3F4→^[3]H_[6]transitions,simultaneous three-wavelength laser operation was achieved.The laser emissions at 2292 and 2363 nm inπ-polarization and at 2108 nm inσ-polarization were realized.With an incident pump power of 22 W,the total output power of 1.17 W at 2292,2363,and 2108 nm was obtained.The output power at 2292 and 2363 nm was measured to be 750 mW,and the output power at 2108 nm was measured to be 420 mW.
文摘目的探讨跨膜蛋白4超级家族5（transmembrane 4 superfamily member 5,TM4SF5）基因多态性、栽脂蛋白E（ApoE）基因多态性和阿尔茨海默病（AD）的相关性。方法通过使用TaqMan—PCR法检测单核苷酸多态性（SNP）方法，在376例日本人AD患者，包括323例迟发型AD（I。OAD）、53例早发型AD（EOAD）和377例非痴呆对照组中观察TM4SF5基因rs4790230（-791T／C）、rs746988（＋1528T／c）、rs2302328（＋11228c／A）及APOE基因的多态性分布，并分析与AD的相关性。结果（1）TM4SF5基因rs4790230（-791T／C）c／c纯合子频率在EOAD中明显高于对照组（0．70比0．52，P值为0．017）；rs2302328（＋11228C／A）携带A等位基因者频率在总AD中略高于对照组（0．88比0．84，P值为0．05）；（2）进一步在非APOE4携带者中分析显示rs4790230（-791T／C）c／c纯合子频率在EOAD中仍明显高于对照组（0．85比0．53，P〈0．001）；（3）单倍型分析显示病例组C—C—A型与C—T—A型频率分别高于时照组（0．29比0．21；0．35比0．16；P〈0．001）；病例组C—T—C型频率低于对照组（0．12比0．28；P〈0．001）。结论TM4SF5基因rs4790230（-791T／C）多态位点独立于APOE与EOAD存在相关性，三位点单倍型C—C—A型与C—T—A型增加了AD的发病风险。
基金supported by the National Natural Science Foundation of China(Nos.51272109 and 50972061)the Natural Science Foundation of Zhejiang Province(No.R4100364)+1 种基金the Natural Science Foundation of Ningbo City(No.2012A610115)the K.C.Wong Magna Fund in Ningbo University
文摘Mid-infrared（MIR） emissions of 2.4 and 3.5 μm from Tm3＋：LiYF4 single crystals attributed to3H4 →3H5 and3H5 →3F4 transitions as well as MIR emissions of 4.2,4.3,and 4.5 μm from Nd3＋：LiYF4 lasers attributed to4I15/2 →4I13/2,4I13/2 →4I11/2,and4I11/2 →4I9/2 transitions,respectively,are observed.LiYF4 single crystals possess high transmittance of over 85% in the 2.5-6 μm range.The large emission crosssections of Tm-doped crystals at 2.4 μm（1.9×10-20cm2） and Nd-doped crystals at 4.2 μm（0.84×10-20 cm2） as well as the high rare-earth doping concentrations,excellent optical transmission,and chemicalphysical properties of the resultant samples indicate that Nd3＋and Tm3＋singly doped crystals may be promising materials for application in MIR lasers.
文摘This study evaluates the long-term radiometric performance of the USGS new released Landsat Collection 1 archive, including the absolute calibration of each Landsat sensor as well as the relative cross-calibration among the four most popular Landsat sensors. A total of 920 Landsat Collection 1 scenes were evaluated against the corresponding Pre-Collection images over a Pseudo-Invariant Site, Railroad Valley Playa Nevada, United States (RVPN). The radiometric performance of the six Landsat solar reflective bands, in terms of both Digital Numbers (DNs) and at-sensor Top of Atmosphere (TOA) reflectance, on the sensor cross-calibration was examined. Results show that absolute radiometric calibration at DNs level was applied to the Landsat-4 and -5 TM (L4 TM and L5 TM) by –1.119% to 0.126%. For L4 TM and L5 TM, the cross-calibration decreased the radiometric measurement level by rescaling at-sensor radiance to DN values. The radiometric changes, –0.77% for L4 TM, 0.95% for L5 TM, –0.26% for L7 ETM+, and –0.01% for L8 OLI, were detected during the cross-calibration stage of converting DNs into TOA reflectance. This study has also indicated that the long-term radiometric performance for the Landsat Collection 1 archive is promising. Supports of these conclusions were demonstrated through the time-series analysis based on the Landsat Collection 1 image stack. Nevertheless, the radiometric changes across the four Landsat sensors raised concerns of the previous Landsat Pre-Collection based results. We suggest that Landsat users should pay attention to differences in results from Pre-Collection and Collection 1 time-series data sets.
