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| 1 | Electronic structure of the SrAl_2O_4:Eu^(2+) persistent luminescence material显示文摘The electronic structure of the strontium aluminate (SrAl2O4:Eu2+) materials was studied with a combined experimental and theoretical approach. The UV-VUV synchrotron radiation was applied in the experimental study while the electronic structure of the non-optimized and optimized crystal structure were investigated theoretically by using the density functional theory. The structure of the va- lence and conduction bands as well as the band gap energy of the material together with the position of the Eu2+ 4f7 8S7/2 ground state were calculated. The calculated band gap energy (6.4 eV) agreed well with the experimental value of 6.6 eV. The valence band consisted mainly of oxygen states whereas the bottom of the conduction band of strontium states. In agreement with the experimental results, the calculated 4f7 8S7/2 ground state of Eu2+ lies in the energy gap of the host. The position of the 4f7 ground state depended on the Coulomb repulsion strength. The position of the 4f7 ground state with respect to the valence and conduction bands was discussed using theoretical and experimental evidence available. | Jorma Hls Taneli Laamanen Mika Lastusaari Janne Niittykoski Pavel Novák | 2009 | Journal of Rare Earths2009，27，4： | 9 |
| 2 | Synchrotron radiation investigations of the Sr_2MgSi_2O_7:Eu^(2+),R^(3+) persistent luminescence materials显示文摘The electronic and defect energy level structure of polycrystalline Sr2MgSi2O7:Eu2+,R3+ persistent luminescence materials were studied with thermoluminescence and different synchrotron radiation spectroscopies (UV-VUV emission and excitation, X-ray absorption near-edge spectroscopy (XANES) and extended X-ray absorption fine structure (EXAFS)). Special attention was paid on the effect of the R3+ co-dopants on the persistent luminescence properties of the materials. Theoretical calculations using the density functional theory (DFT) were carried out simultaneously with the experimental work. The experimental band gap energy (Eg) value of ca. 7.1 eV agreed very well with the DFT value of 6.7 eV. The variation of the Eg value was attempted to relate with the trap structure as well as with the different properties of the R3+ co-dopants. The trap level energy distribution depended strongly on the R3+ co-dopant except for the shallowest trap energy above the room temperature remaining practically the same, however. The different processes in the mechanism of persistent luminescence from Sr2MgSi2O7:Eu2+,R3+ were assembled and their contributions discussed. | Tuomas Aitasalo Jukka Hassinen Jorma Hls Taneli Laamanen Mika Lastusaari Marja Malkamki Janne Niittykoski Pavel Novák | 2009 | Journal of Rare Earths2009，27，4： | 5 |
| 3 | Defect aggregates in the Sr_2MgSi_2O_7 persistent luminescence material显示文摘The crystal and electronic structure of the Eu2+ doped and defect containing Sr2MgSi2O7 persistent luminescence material were studied using the density functional theory(DFT) .The defects may act as energy storage or even luminescence quenching centres in these materials,however their role is very difficult to confirm experimentally.The probability of vacancy formation was studied using the total en-ergy of the defect containing host.Significant structural modifications in the environment of the isolated defects,especially the strontium va-cancy,as well as defect aggregates were found.The experimental band gap energy of Sr2MgSi2O7 was well reproduced by the calculations.The defect induced electron traps close to the host's conduction band were found to act as energy storage sites contributing to its efficient per-sistent luminescence.The interactions between the defects were found to modify both the Eu2+ 4f7 ground state energy as well as the trap structure.The effect of charge compensation induced by the rare earth co-doping on the defect structure and energy storage properties of the persistent luminescence materials was discussed. | Jorma Hls Taneli Laamanen Mika Lastusaari Pavel Novák | 2011 | Journal of Rare Earths2011，29，12： | 2 |
| 4 | Selectivegrowth of SWNTs on partially reduced monometalliccobait catalyst 显示文摘 | Maoshuai H Alexander I C Pavel V F | 2011 | Chem Commun2011，47，： | 1 |
| 5 | Controversy over the great flood hypotheses in the Black Sea in light of geological, paleontological, and archaeological evidence显示文摘 | VALENTINA Y H ALLAN S G PAVEL D | 2007 | Quaternary International2007，，7： | 1 |
| 6 | Evaporation changes over the contiguous United States and the former USSR:A reassessment显示文摘 | Valentin S Golubev Jay H Lawrimore Pavel Ya Groisman | 2006 | Geophysical Research Letters2006，28，13： | 1 |
| 7 | Apoptosls and expression of Bcl-2 in human endometrium in natural and artificial cycles显示文摘 | PAVEL H IVANA O JANA B | 2005 | Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub2005，149，2： | 1 |
| 8 | Metastasis:newperspectives on an old problem显示文摘 | Kraljevic Pavelic S Sedic M Bosnjak H | 2011 | Mol Cancer2011，10，： | 1 |
| 9 | Altered β-adrenergic regulation of Na-K-Cl cotransport in cultured smooth muscle cells from the aorta of spontaneously hypertensive rats role of the cytoskeleton network显示文摘 | Sergei NO Johanne T Pavel H | 1995 | Am J Hypertens1995，8，7： | 1 |
| 10 | Variability of phase shift between blood pressure and heart rate fluctuations显示文摘 | Josef H Tomás K Pavel J | 2003 | Circulation2003，108，： | 1 |
| 11 | Disturbed melanin synthesis and chronic oxidative stress in dysplastic naevi显示文摘 | van Nieuwpoort F van der Meulen H | 2004 | Eur J Cancer2004，40，9： | 1 |
| 12 | 显示文摘 | Pavel C Zverev P G Jelinkova H | 2000 | Optics Communications2000，177，： | 1 |
| 13 | Efficient Raman Shifting of Picosecond Pulses Using BaWO4 Crystal 显示文摘 | Cerny Pavel Zverev P G Jelinkova H Basiev T T | 2000 | Optics Communications2000，177，16： | 1 |
| 14 | Optimal control and control-lability problems for a class of nonlinear degenerate dif-fusion equations显示文摘 | Gao H Hou X Z Pavel N | 2003 | Paname MathJ2003，13，： | 1 |
| 15 | Efficacy and safety of immediate angioplasty versus ischemia-guided management after thrombolysis in acute myocardial infarction in areas with very long transfer distances results of the NORDISTEMI (NORwegian study on District treatment of ST-elevation myocardial infarction) 显示文摘 | Ellen B Pavel H Michael A | 2009 | Am Col Card J2009，，2： | 1 |
| 16 | Erythromycin stearate as prokinetic agent in postvagotomy gastroparesis显示文摘 | Mozwecz H Pavel D Pitrak D | 1992 | Dig Dis Sci1992，35，： | 1 |
| 17 | Cyclic nucleotide-dependent protein kinases inhibit binding of 14-3-3 to the GTPase-activating protein rap1GAP2 in platelets显示文摘 | Meike H Pavel R Albert PS | 2008 | J Biol Chem2008，283，4： | 1 |
| 18 | Anti - periodic boundary value problems for higher order differential equations in Hilbert spaces 显示文摘 | AFTABIZADEH A R AIZICOVICI S PAVEL N H | 1992 | Nonlinear Analysis1992，18，3： | 1 |
| 19 | Recent developments and emerging directions in ion chromatography显示文摘 | Paul R H Pavel N N Wolfgang B | 2008 | Journal of Chromatography A2008，1184，： | 1 |
| 20 | Nonlinear third - order differential equations with anti - periodic boundary conditions and some optimal control problems显示文摘 | AFTABIZADEH A R HUANG Y K PAVEL N H | 1995 | J Math Anal Appl1995，192，1： | 1 |
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