Energy transfer among Pb, Ce and Mn in fluorescent calcite from Kuerle, Xinjiang, China     

Aierken Sidike  X.-M. Wang  Alifu Sawuti  H.-J. Zhu  I. Kusachi  N. Yamashita 《Physics and Chemistry of Minerals》2006,33(8-9):559-566

Natural calcite from Kuerle, Xinjiang, China, shows orange-red fluorescence when exposed to short-wave ultraviolet (UV) light (Hg 253.7 nm). Photoluminescence (PL) emission and excitation spectra of the calcite are observed at room temperature in detail. The PL emission spectrum under 208 nm excitation consists of three bands: two UV bands at 325 and 355 nm and an orange-red band at 620 nm. The three bands are ascribed to Pb²⁺, Ce³⁺ and Mn²⁺, respectively, as activators. The Pb²⁺ excitation band is observed at 243 nm, and the Ce³⁺ excitation band at 295 nm. The Pb²⁺ excitation band is also observed by monitoring the Ce³⁺ fluorescence, and the Pb²⁺ and Ce³⁺ excitation bands, in addition to six Mn²⁺ excitation bands, are also observed by monitoring the Mn²⁺ fluorescence. These indicate that four types of the energy transfer can occur in calcite through the following processes: (1) Pb²⁺ → Ce³⁺, (2) Pb²⁺ → Mn²⁺, (3) Ce³⁺ → Mn²⁺ and (4) Pb²⁺ → Ce³⁺ → Mn²⁺.  相似文献   

Photoluminescence of baratovite and katayamalite     

Aierken Sidike  S. Kobayashi  Heng-Jiang Zhu  I. Kusachi  N. Yamashita 《Physics and Chemistry of Minerals》2010,37(10):705-710

The photoluminescence (PL) and optical excitation spectra of baratovite in aegirine syenite from Dara-i-Pioz, Tien Shan Mts., Tajikistan and katayamalite in aegirine syenite from Iwagi Islet, Ehime, Japan were obtained at 300 and 80 K. Under short wave (253.7 nm) ultraviolet light, baratovite and katayamalite exhibited bright blue-white luminescence. The PL spectrum of baratovite at 300 K consisted of a wide band with a peak at approximately 406 nm and a full width at half maximum (FWHM) of approximately 6.32k cm⁻¹. The excitation spectrum of the blue-white luminescence from baratovite at 300 K consisted of a prominent band with a peak at approximately 250 nm. The PL and excitation spectra of katayamalite were similar to those of baratovite. The luminescence from these minerals was attributed to the intrinsic luminescence from the TiO₆ center.  相似文献   

Yellow fluorescence from baghdadite and synthetic Ca3(Zr,Ti)Si2O9     

Aierken Sidike  I. Kusachi  N. Yamashita 《Physics and Chemistry of Minerals》2006,32(10):665-669

Baghdadite from Fuka, Okayama Prefecture, Japan shows a bright yellow fluorescence under UV (Hg 253.7 nm) excitation. The photoluminescence (PL) spectrum at 300 K consists of one large band near 580 nm and two small UV bands at 318 and 397 nm. The optical excitation spectrum of the bright yellow fluorescence consists of two bands near 220 and 250 nm. The temperature dependence of the PL intensity exhibits linear thermal quenching. To reveal the origin of the bright yellow fluorescence from baghdadite, powder Ca₃(Zr,Ti)Si₂O₉ crystals are synthesized. Synthetic Ca₃(Zr,Ti)Si₂O₉ shows luminescence spectra similar to those of baghdadite, and the intensity of the yellow fluorescence is markedly increased by titanium addition. The origin of the bright yellow fluorescence from baghdadite is ascribed to the existence of titanium.  相似文献   

塔里木河下游河岸胡杨(Populus euphratica)林耗水过程模拟     

苏里坦  李玉生  艾尔肯·艾比布拉  赵天宇 《中国沙漠》2015,(2):380-384

选择塔里木河下游主要植物胡杨(Populus euphratica)林,以大气温度、太阳净辐射、大气相对湿度、冠层顶风速、地下水位和胡杨树茎横截面积为影响胡杨林耗水量的自变量,基于最小二乘法建立了多重线性回归模型、非线性回归模型和完全二次回归模型,并应用模型对塔里木河下游河岸胡杨林的耗水过程进行了日尺度上的模拟研究。结果表明:3个回归模型均表现出较好的模拟效果,其中完全二次回归模型的模拟精度最高,模型中大气温度、地下水位和胡杨树茎横截面积是影响胡杨耗水量的诸多环境因子中最敏感的因子;胡杨林的耗水量观测值与模拟值表现出较好的相关性,3个回归模型的模拟值与观测值的相关系数依次分别为0.6793、0.7299、0.7574,其相对误差分别为28.7%、26.1%、22.9%,其显著性水平均通过95%显著性检验;3个回归模型中完全二次回归模型具有使用简便、影响因子易测定、有一定精度等优点,能够更好刻画植被腾发量的复杂非线性特性,为干旱区自然植被耗水量估算、模拟和生态需水量计算提供了新的思路和方法。  相似文献   

Photoluminescence properties of green and red luminescence from natural and heat-treated sodalite     

Muyasier Kaiheriman  Alitunguli Maimaitinaisier  Aziguli Rehiman  Aierken Sidike 《Physics and Chemistry of Minerals》2014,41(3):227-235

The sodalite sample used in this investigation did not exhibit the characteristic orange-yellow luminescence due to the $ {\text{S}}_{ 2}^{ - } $ center, because there was no trace of sulfur impurity. The heat-treated samples exhibited green and red luminescence with maximum intensity at 496 and 687 nm, respectively, under 264 nm excitation at room temperature. Their luminescence intensities were extensively dependent on the treatment temperature. The green luminescence efficiency of the sample heat-treated at 900 °C was 6.5 times higher than that of unheated natural sodalite. At 8.5 K, the green luminescence showed a vibronic structure. After heating at 1,300 °C, the crystal structure of sodalite was transformed to NaAlSiO₄ (carnegieite), and the intense red luminescence was exhibited in the NaAlSiO₄ sample. The peak wavelength of the red luminescence shifted from 687 nm at 300 K to 726 nm at 8.5 K. The luminescence lifetimes of the green and red luminescence at room temperature were 2.1 and 5.1 ms, respectively. It was proposed that the origin of the green luminescence is Mn²⁺ replacing Na⁺, and that of the red luminescence is Fe³⁺ replacing Al³⁺ in sodalite or NaAlSiO₄ (carnegieite).  相似文献   

Luminescence spectra of chabazite-Ca,a zeolite mineral     

S.?Kobayashi  Aierken Sidike  N.?YamashitaEmail author 《Physics and Chemistry of Minerals》2012,39(6):465-470

Chabazite-Ca deposited on dacite laccolith from Osódi Hill, Dunabogdány, Hungary, exhibited bluish-white luminescence under ultraviolet (UV) light. The photoluminescence (PL) and optical excitation spectra of chabazite-Ca were obtained at 300 K. The PL spectrum under 300-nm excitation consists of (1) a Ce³⁺ band with a peak at 340 nm, (2) a broad main band with a peak at 453 nm and (3) five narrow bands at 592, 616, 650, 700 and 734 nm due to Eu³⁺. The main band is spread over the entire visible-wavelength region. The excitation spectrum obtained by monitoring green luminescence at 520 nm consists of a band at wavelengths shorter than 200 nm and an extremely broad band with a peak at 385 nm. The extremely broad band is spread over not only the UV region but also the blue region. The features of PL and excitation spectra suggest that the origin of bluish-white luminescence is luminescent organic matter incorporated into chabazite-Ca crystals during growth.  相似文献   

Photoluminescence properties of thenardite from Ai-Ding Salt Lake,Xinjiang, China     

Aierken Sidike  Keyoumu Niyazi  Heng-Jiang Zhu  K. Atobe  N. Yamashita 《Physics and Chemistry of Minerals》2009,36(3):119-126

The photoluminescence (PL) spectra, excitation spectra, and PL decay curves of natural, heat-treated, and γ-ray-irradiated thenardites from Ai-Ding Salt Lake, Xinjiang, China, were studied. The natural thenardite under 300 nm excitation showed milk-white luminescence, and the PL spectrum consisted of an extremely broad band with a peak located at approximately 509 nm, spreading over a wide range of UV and visible wavelengths. The excitation spectra, obtained by monitoring the luminescence at 530 nm, consisted of a broad band with a peak located at approximately 235 nm and a flat band spreading over a wide range of UV and visible wavelengths. The PL decay curve of natural thenardite consisted of a fast-decay component with a lifetime of less than 0.1 μs and a slow-decay component with a half-decay time of approximately 0.4 s. The heat treatment of thenardite at 900°C for 20 min reduced the luminescence efficiency to 1/100. The γ-ray irradiation of thenardite reduced the luminescence efficiency to approximately half.  相似文献   

Photoluminescence properties of anthophyllite     

Aierken Sidike  Nuerrula Jilili  S. Kobayashi  K. Atobe  Nobuhiko Yamashita 《Physics and Chemistry of Minerals》2010,37(2):83-89

The photoluminescence (PL) spectra, optical excitation spectra and PL decay curves of anthophyllite from Canada were obtained at 300 and 10 K. The MnO content in the sample, determined using an electron probe microanalyzer, was high at 5.77 wt%. In the PL spectra obtained under 410-nm excitation, bright red bands with peaks at 651 and 659 nm were observed at 300 and 10 K, respectively. The origin of the red luminescence was ascribed to Mn²⁺ in anthophyllite from the analysis of the excitation spectra and PL decay times of 6.1–6.6 ms. In the PL spectra obtained under 240-nm excitation at 300 K, a small violet band with a peak at 398 nm was observed. On the violet band at 10 K, a vibronic structure was observed. The origin of the violet luminescence was attributed to a minor impurity in anthophyllite.  相似文献   

Natural fluorite emitting yellow fluorescence under UV light   总被引：1，自引：0，他引：1  

Aierken?Sidike  I.?Kusachi  N.?YamashitaEmail author 《Physics and Chemistry of Minerals》2003,30(8):478-485

Many mineralogists believe that fluorite emits violet fluorescence under UV light, but a special fluorite from Japan emits yellow fluorescence under UV light. The analysis by inductively coupled plasma-mass spectrometry (ICP-MS) shows that this fluorite includes high concentrations of Dy together with various rare-earth (RE) impurities other than Pm and Eu. Photoluminescence (PL) emission and excitation spectra of the fluorite are investigated at 10, 80 and 300 K. The origin of yellow fluorescence is attributed to the electronic transition within Dy³⁺. Profiles of the PL and excitation spectra depend on the excitation wavelength and on the observation wavelength, respectively. The obtained spectra are ascribed to the RE ions Ce³⁺, Sm³⁺, Tb³⁺, Dy³⁺, Ho³⁺, Er³⁺, Sm²⁺ and Yb²⁺ in the fluorite. In natural fluorite, the low concentration of Eu enables us to observe the bright fluorescence characteristic of trivalent RE ions, instead of the bluish violet fluorescence due to Eu²⁺.  相似文献   

Fine structure in photoluminescence spectrum of S<Subscript>2</Subscript><Superscript>−</Superscript> center in sodalite     

Aierken Sidike  Alifu Sawuti  Xiang-Ming Wang  Heng-Jiang Zhu  S. Kobayashi  I. Kusachi  N. Yamashita 《Physics and Chemistry of Minerals》2007,34(7):477-484

The photoluminescence and excitation spectra of sodalites from Greenland, Canada and Xinjiang (China) are observed at 300 and 10 K in detail. The features of the emission and excitation spectra of the orange-yellow fluorescence of these sodalites are independent of the locality. The emission spectra at 300 and 10 K consist of a broad band with a series of peaks and a maximum peak at 648 and 645.9 nm, respectively. The excitation spectra obtained by monitoring the orange-yellow fluorescence at 300 and 10 K consist of a main band with a peak at 392 nm. The luminescence efficiency of the heat-treated sodalite from Xinjiang is about seven times as high as that of untreated natural sodalite. The emission spectrum of the S₂ ⁻ center in sodalite at 10 K consists of a band with a clearly resolved structure with a series of maxima spaced about 560 cm⁻¹ (20–25 nm) apart. Each narrow band at 10 K shows a fine structure consisting of a small peak due to the stretching vibration of the isotopic species of ³²S³⁴S⁻, a main peak due to that of the isotopic species of ³²S₂ ⁻ and five peaks due to phonon sidebands of the main peak.  相似文献