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101.
102.
J.P. Seitz B.B. Back M.P. Carpenter I. Diszegi K. Eisenman P. Heckman D.J. Hofman M.P. Kelly T.L. Khoo S. Mitsuoka V. Nanal T. Pennington R.H. Siemssen M. Thoennessen R.L. Varner 《Nuclear Physics A》2005,750(2-4):245-255
The giant dipole resonance built on excited states was observed in very fissile nuclei in coincidence with evaporation residues. The reaction 48Ca + 176Yb populated evaporation residues of mass A=213–220 with a cross section of 200 μb at 259 MeV. The extracted giant dipole resonance parameters are in agreement with theoretical predictions for this mass region. 相似文献
103.
采用顶部籽晶提拉法(TSSG)生长出Yb:KY(WO4)2(Yb:KYW)激光晶体.对预烧后的原料及晶体进行了XRD分析,结果表明,分别在920℃和600℃预烧8h后的熔质和助熔剂基本上形成一相,抑止了实验中的挥发问题;所生长的晶体为β-Yb:KYW,计算其晶格常数为a=1.063nm,b=1.034nm,c=0.755nm,β=130.75°.测得不同厚度样品的吸收光谱,结果表明样品在933nm和981nm有较强的吸收峰,计算出主峰981nm的吸收截面σabs=5.34×10-20cm2.测得样品的荧光光谱,计算出主峰1030nm受激发射截面σem=3.1×10-20cm2,并估算其荧光寿命为0.56ms,与实测值0.60ms吻合.计算出激发态最小粒子数(β)、饱和抽运强度(Isat)和最小抽运强度(Imin),通过与其他掺Yb3+晶体比较,结果表明Yb:KYW晶体的Imin(0.24kW/cm2)很小. 相似文献
104.
106.
Yb3+:KGd(WO4)2材料的频率上转换发光 总被引:3,自引:0,他引:3
采用固相合成法 ,在 10 0 0℃烧结合成了一系列掺有Yb3 摩尔分数分别为x =0 0 3,0 0 8,0 10 ,0 12 ,0 15 ,0 18,0 2 0 ,0 2 5 ,0 2 8的KYbxGd( 1 -x) (WO4 ) 2 粉末样品。采用 980nm波长的LD泵浦源和RF 5 4 0荧光光谱仪 ,对这一系列掺有不同Yb3 摩尔分数的KYbxGd( 1 -x) (WO4 ) 2 粉末样品进行了荧光光谱的测定研究。结果表明 ,在 10 2 0nm处得到一个较弱的荧光峰 ,而在 4 76nm处得到很强的蓝色发光谱带。同时测定了蓝色发光强度与样品掺杂Yb3 摩尔分数的关系 ,随着Yb3 掺杂摩尔分数的增加 ,蓝色发光强度也随着迅速地增强 ,当Yb摩尔分数为 2 5 %时 ,荧光强度达到最大 ,然后 ,随着Yb掺杂摩尔分数的增加 ,蓝色发光强度也随着迅速地衰弱。当Yb掺杂摩尔分数为 8%~ 10 % ,10 2 0nm处的荧光强度达到最大。 相似文献
107.
A. Bensalah M. Nikl E. Mihokova N. Solovieva A. Vedda H. Sato T. Fukuda G. Boulon 《Radiation measurements》2004,38(4-6):545-548
Single crystals of Yb2+-doped LiCaAlF6 were grown by the Czochralski technique under CF4 atmosphere. Photoluminescence, thermally stimulated luminescence and decay kinetics of Yb2+ centre in the LiCaAlF6 host were measured in the 4–300 K temperature interval. Phenomenological two excited-state-level model is introduced to obtain quantitative characteristics of the excited state dynamics of Yb2+. The role of Yb2+ centre in trapping processes is discussed. Moreover, defect centres related to LiCaAlF6 host were found. 相似文献
108.
以1 030 nm高反,940,980 nm高透的波长分离膜作为实例,为提高该薄膜元件的波长分离效果,从膜系的优化方面做了一系列的研究,诸如采用带通滤光片的设计思想,在膜堆两侧加入了匹配层,调整膜堆的周期厚度,并用膜系设计软件对通带作进一步的优化.通过这一系列的优化设计后,利用RF双离子束溅射工艺在BK7玻璃基底上沉积样品薄膜,并在基底背面加镀通带增透膜.结果显示,透射带在940和980 nm处的透过率分别为97.73%和93.63%,反射带在1 030 nm的反射率为99.99%.对所制备的样品薄膜进行了激光损伤阈值测量,得到了35 J/cm2(1 064 nm,12 ns)的结果. 相似文献
109.
Aaron P. Holm Susan M. Kauzlarich Simon A. Morton James G. Tobin 《Journal of solid state chemistry》2005,178(1):262-269
Measurements of core and valence electronic states of single crystals of the rare earth transition metal Zintl phases Yb14MnSb11 and Yb14ZnSb11 were performed using the X-ray photoelectron spectroscopy station of Beamline 7 at the Advanced Light Source. Sample surfaces of Yb14MnSb11 and Yb14ZnSb11 were measured as received, after Ar+ ion bombardment, and after cleaving in situ. The single crystal structure of Yb14ZnSb11 is also reported. Both compounds are air-sensitive and show Yb3+ due to surface oxidation. In the case of Yb14MnSb11, there is no evidence for Yb3+ that would be intrinsic to the sample, consistent with previously reported X-ray magnetic circular dichroism studies. Detailed analyses of the Yb14ZnSb11 surfaces reveal a significant contribution of both Yb3+ and Yb2+ 4f states in the valence band region. This result is predicted for the Zn analog by Zintl counting rules and support the mixed valency of Yb for Yb14ZnSb11. Further detailed analysis of the core and valence band structure of both Yb14MnSb11 and Yb14ZnSb11 is presented. 相似文献
110.
Park H Kwon DH Rhee Y 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2004,60(14):259-3309
Based on laser absorption spectroscopy (LAS), we developed a vapor density monitor for controlling the vaporization rate of Yb using a tunable diode laser. The laser source consisted of an extended cavity violet diode laser which has an emission wavelength of 398.8 nm coincident with the Yb absorption transition line, 6s(2) 1S(0)-6s6p 1P(1). The light emitted from the diode laser was transmitted across an atomic vapor column generated by heating the Yb metal, while the laser frequency was scanned across the atomic transition line. By comparing the amount of incident light to the amount of light transmitted after the light passed through the vapor column, the vapor density was determined using the Beer's law. From the experimental results, we demonstrated that the diode-laser-based LAS operated successfully for the real-time monitoring of the Yb vapor density. 相似文献