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Zhang M.,The Key Laboratory of Weak Light Nonlinear Photonics | Zhang M.,Nankai University | Yu H.,The Key Laboratory of Weak Light Nonlinear Photonics | Yu H.,Nankai University | And 3 more authors.
Faguang Xuebao/Chinese Journal of Luminescence | Year: 2011

Optically transparent Er 3+/Yb 3+ codoped glass ceramics based on the system 60TeO 2-10CaF 2-25H 3BO 3 - 1Er 2O 3-4Yb 2O 3 have been successfully prepared by melt-quenching method at 900°C.The Er 2Te 5O 13 nanocrystals, whose phonon energy was 886 cm -1 by Raman measurement, were characterized by XRD and TEM in the tellurite glass ceramics. Both up-conversion and down-conversion emission spectra were measured. The red and green emissions have different luminescent processes under different excitation sources. The energy transfer processes were discussed individually.

Zhang X.,Nankai University | Liu X.,Nankai University | Pan L.,Nankai University | Pan L.,The Key Laboratory of Weak Light Nonlinear Photonics | And 2 more authors.
Biochemical and Biophysical Research Communications | Year: 2010

Several studies have been undertaken to elucidate the effects of electromagnetic field (EMF) on intracellular calcium ([Ca2+]i) in the past 20 years. However, still there were controversies of electromagnetic pollution within the scientific community. In this work, we studied the effects of alternative magnetic fields on intracellular calcium. Osteoblastic cells were used as a model both to test the hypothesis that extremely low-frequency (ELF) magnetic fields can alter the concentrations of the intracellular calcium, and to examine the 'window' effect predicted by our previous theoretical work. The outcome of this experiment demonstrated that 50 Hz, 0.8 mT magnetic field can induce the uptake of [Ca2+]i in osteoblasts. The empirical evidences of the specified window effects of [Ca2+]i in osteoblastic cells were reported for the first time in this work. © 2010 Elsevier Inc. All rights reserved.

PubMed | The Key Laboratory of Weak Light Nonlinear Photonics
Type: Journal Article | Journal: Physical chemistry chemical physics : PCCP | Year: 2013

A series of rare earth (RE) doped oxyfluoride glasses with the composition of (45-x) SiO2-5Al2O3-40PbF2-10CdF2-xRe2O3 (x = 1, 5, 10, 15) (mol%) were prepared by a traditional melt-quenching method. Glass ceramics (GCs) were obtained after thermal treatment and characterized by X-ray diffraction (XRD) to investigate the nanocrystal structure and distortion. Both the dopant type and the doping level play an important role in the distortion of the PbF2-RE lattice. It is found that a cubic Pb3REF9 phase forms in low doping GCs, a tetragonal PbREF5 phase forms in middle doping GCs and cubic PbRE3F11 forms in high doping GCs. Accordingly, the site symmetry of RE(3+) dopants in -PbF2 nanocrystal undergoes a transition of OhD4hOh with the increase of doping level. The change in the ligands coordinating the RE(3+) ions was further illustrated by the optical changes in Yb-doped GCs. This paper provides insights on the nanocrystal structure of RE at the atomic level and tries to make a complete description of the nanocrystal structure and distortion in these glass-ceramic materials, which will benefit the optimization of optical properties.

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