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纳米YPO_4:Pr^(3+)的化学制备、结构分析和光谱特性

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发光学报 1999年第2期20卷 102-105页

作者：廉锐尹民张慰萍霍承松吴伟达夏上达中国科学技术大学结构分析开放实验室中国科学技术大学物理系

首次报道了纳米ＹＰＯ４Ｐｒ３＋粉末材料的化学制备方法和光谱特性，结构分析证实共沉淀法制得的样品为粒径２０ｎｍ的纳米微晶．对激发Ｐｒ３＋离子３Ｐ０能级下的光谱性能进行了测量，同在体材料中一样，得到了来自较高能级３Ｐ１强... 详细信息

首次报道了纳米ＹＰＯ４Ｐｒ３＋粉末材料的化学制备方法和光谱特性，结构分析证实共沉淀法制得的样品为粒径２０ｎｍ的纳米微晶．对激发Ｐｒ３＋离子３Ｐ０能级下的光谱性能进行了测量，同在体材料中一样，得到了来自较高能级３Ｐ１强发射．

关键词：纳米光谱磷酸钇掺镨结构制备

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关于物理系教改若干重要问题的浅见

研究生教育研究 1996年第1期 54-56页

作者：夏上达

关于物理系教改若干重要问题的浅见夏上达根据过去三年在本系分管教学工作的感受，关干我系教改中若干重要问题，我有如下一些浅见。其中已在进行的一部份主要是依据学校的统一部署在推进，还有不少是尚处于酝酿和议沦阶段的想法。（一... 详细信息

关于物理系教改若干重要问题的浅见夏上达根据过去三年在本系分管教学工作的感受，关干我系教改中若干重要问题，我有如下一些浅见。其中已在进行的一部份主要是依据学校的统一部署在推进，还有不少是尚处于酝酿和议沦阶段的想法。（一）从高年级分流出一些学生，加强其工...

关键词：固体物理研究生重要问题物理系物理实验教改五年制科技英语本科生教学改革

YBO_3∶Eu中发光中心的格位与晶场拟合

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中国稀土学报 2001年第6期19卷 507-510页

作者：闫阔宁利新金健健张巍巍张慰萍夏上达中国科学院结构分析开放研究实验室安徽合肥230026 中国科学技术大学物理系安徽合肥230026

通过对溶胶凝胶法制备的YBO3∶Eu的光致发射谱进行分析 ,证实Eu3+ 可能占据两种晶场格位。并采用晶场拟合的方法定量确认这两种晶场格位的对称性分别为C3v和D3,这种指认下能级的拟合结果以及点群选择律和实验结果相当吻合。

关键词：稀土格位对称性晶场拟合 YBO3:Eu 光致发射谱荧光基质材料硼酸钇掺杂铕

CALCULATION OF HUANG-RHYS PARAMETERS AND THEORETICAL ANALYSIS OF INTEGRATED INTENSITIES AND PROFILE OF d-d OPTICAL SPECTRA lN NON-CONDON APPROXIMATION

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Science China Mathematics 1992年第5期35卷 587-596页

作者：刘世宇夏上达汪克林 Department of Physics University of Science and Technology of China Hefei 230026 PRC Department of Physics University of Science and Technology of China Hefei 230026 PRC Fundamental Physics Center Unirersity of Science and Technology of China Hefei 230026 PRC

We develop in this paper the theory of multiphonon radiative transition so that someimportant physical quantities that describe effect s of lattice relaxation in electron transitions,for example, Huang--Rhys parameters, lattice relaxation energies and Stokes shifts, becomecomputable directly. The calculated results of the se physical quantities for alexandrite agreewith experimental data very well. Besides, we deduce expressions of intensity distributionand integrated intensity of a multiphonon sideband in non--Condon approximation. The cal-culated values of integrated intensities are obviously better than the intensity fitting resultsof previous work. From these calculated values we can also acquire a quantitative under-standing of the errors of Condon approximation.

关键词： lattice relaxation Huang-Rhys parameter non-Condon approximation

First-principles study of the local structure and crystal field of Yb^(2+) in sodium and potassium halides

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Chinese Physics B 2012年第3期21卷 349-354页

作者：闻军段昌奎尹民 Yu.V.Orlovskii 夏上达章永凡 Department of Physics University of Science and Technology of China Prokhorov General Physics Institute RAS 38 Vavilov st.Moscow 119991Russia Institute of Physics University of TartuRiia 142Tartu 51014Estonia Department of Chemistry Fuzhou University

The local coordination structures around the doping Yb2＋ ions in sodium and potassium halides were calculated by using the first-principles supercell model. Both the cases with and without the charge compensation vacancy in the local environment of the doping Yb2＋ were calculated to study the effect of the doping on the local coordination structures of Yb2＋. Using the calculated local structures, we obtained the crystal-field parameters for the Yb2＋ ions doped in sodium and potassium halides by a method based on the combination of the quantum-chemical calculations and the effective Hamiltonian method. The calculated crystal-field parameters were analyzed and compared with the fitted results.

关键词： sodium and potassium halides local coordination structure distortion crystal-field parameters

Structure Property and Visible Upconversion of Er^(3+) Doped Gd_2O_3 Nanocrystals

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Journal of Rare Earths 2004年第3期22卷 365-369页

作者：郭海张慰萍尹民楼立人夏上达 Structure Research Laboratory University of Science and Technology of China Chinese Academy of Sciences Hefei 230026 China Department of Physics University of Science and Technology of China Hefei 230026 China

Gd_2O_3∶Er nanoparticles were prepared by a simple sol-gel method. The structure properties of Gd_2O_3∶Er were studied by X-ray diffraction, transmission electron microscopy, Raman spectroscopy and Fourier transform infrared spectroscopy. The visible up-converted luminescence spectra of Er^(3+) were investigated under excitation to (()~4I_(9/2)) level by 785 nm laser. Laser power, Er^(3+) ion concentration and temperature dependences of the upconverted emissions were investigated to understand the upconversion mechanisms. Excited state absorption and energy transfer process are discussed as the possible mechanisms for the upconversion.

关键词： optics upconversion luminescence sol-gel Gd_2O_3∶Er^(3+) rare earths

Optical Properties and Spectroscopic Parameters of Sm(DBM)_3 Doped Polymethyl Methacrylate

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Journal of Rare Earths 2004年第1期22卷 31-35页

作者：董宁陈彪尹民宁利新张其锦夏上达 Structure Research Laboratory Department of Polymer Science and Engineering

Optical absorption spectra of Sm(DBM) 3 doped PMMA (polymethyl methacrylate) in near infrared and visible region are presented. The energy levels were assigned and analyzed in terms of the free-ion Hamiltonian model. Energy levels and reduced matrix elements calculations were carried out using the complete 198 SLJ basis sets for the 4f5 configuration. Judd-Ofelt parameters were evaluated and used to predict the radiative properties of the sample. The theoretical and experimental values for radiative lifetimes and branching ratios were discussed.

关键词： optics radiative properties Judd-Ofelt theory PMMA rare earths

人工金刚石薄膜生长过程中有关反应活性的研究

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物理学报 1995年第5期44卷 763-771页

作者：潘必才夏上达方容川中国科学技术大学物理系合肥230026

用原子簇团模拟人工金刚石膜生长过程中的一些生长核,采用从头自治的DV-X_n方法对这些簇团和与生长过程有关的一些气相分子和基团(CH,CH_2,CH_3,·CH_3,CH_4·H,C_2H,C_2H_2,C_2H_4)进行了电子结构计算,从化学反应活性的角度探讨金刚石... 详细信息

用原子簇团模拟人工金刚石膜生长过程中的一些生长核,采用从头自治的DV-X_n方法对这些簇团和与生长过程有关的一些气相分子和基团(CH,CH_2,CH_3,·CH_3,CH_4·H,C_2H,C_2H_2,C_2H_4)进行了电子结构计算,从化学反应活性的角度探讨金刚石膜生长过程中这些气相分子和基团与生长核的反应活性,结果表明,CH,CH_2,CH_3,CH_4·H和变形的C_2H_2更易于与金刚石表面发生化学吸附。另外,通过分析簇团的电子态密度和前线分子轨道的组成情况,提出了人工金刚石膜生长中生长核长大的图象。

关键词：金刚石人工金刚石薄膜薄膜生长反应活性

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二晶场参数拟合下金绿宝石的能级分裂链

Chinese Journal of Chemical Physics 1989年第4期2卷 284-290页

作者：刘世宇夏上达中国科学技术大学物理系

对(声子边带)可调谐激光晶体金绿宝石(BeAl_2O_4:Cr^(3+))中Cr^(3+)的(3d^3)组态,在O_hC_(3v)C_s逐级近似对称下,用两晶场参量拟合方法得到了全部50个能级的晶场分裂链和相应的波函数,可用于讨论静态奇宇称晶场微扰及电子—声子耦... 详细信息

对(声子边带)可调谐激光晶体金绿宝石(BeAl_2O_4:Cr^(3+))中Cr^(3+)的(3d^3)组态,在O_hC_(3v)C_s逐级近似对称下,用两晶场参量拟合方法得到了全部50个能级的晶场分裂链和相应的波函数,可用于讨论静态奇宇称晶场微扰及电子—声子耦合诱导的d-d跃迁谱强等问题。

关键词：金绿宝石激光日体能级分裂链