排序方式: 共有26条查询结果,搜索用时 15 毫秒
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S.S. Pote C.P. Joshi S.V. Moharil P.L. Muthal S.M. Dhopte 《Physica B: Condensed Matter》2011,406(6-7):1308-1311
Some compounds with fluorite structures in the system CaF2–YF3 were prepared by precipitation followed by thermal annealing at 1000 °C. Photoluminescence spectra of Ce3+ and Eu2+ were studied. In this host, Ce3+ exhibits PL, which is totally different from that observed for the constituent fluorides. Eu2+ emission, on the other hand, is almost the same as that for CaF2. The changes are explained in terms of the defect structure of Ca1?xYxF2+x. 相似文献
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S. V. Moharil S. V. Bodade P. D. Sahare S. M. Dhopte P. L. Muthal V. K. Kondawar 《辐射效应与固体损伤》2013,168(2):177-182
Abstract LiNaSO4: Eu is a recently discovered thermoluminescence dosimetry (TLD) phosphor which is more sensitive than the widely used CaSO4:Dy. In this paper results are reported on TL glow curves, TL emission spectra and PL photoluminescence. These measurements help to understand the role of impurity and the mechanism of thermoluminescence in this phosphor. 相似文献
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M. S. Atone S. J. Dhoble S. V. Moharil S. M. Dhopte P. L. Muthal V. K. Kondawar 《辐射效应与固体损伤》2013,168(2):225-230
Abstract Photoluminescence and thermoluminescence in BaSO4:Eu is reported. In earlier works, divalent Eu has been studied in BaSO4. In the present work Eu was incorporated as in predominantly Eu3+ or Eu2+ form. It is shown that RE3+ ? RE2+ conversion or RE2+ ? RE+ conversion is not an integral part of gamma induced TL. Eu3+ ? Eu2+ conversion, on the other hand, may be important in UV induced TL. Low UV efficiency of this material is attributed to poor Eu3+ ? Eu2+ conversion. This is in quite contrast to the analogus material CaSO4: Eu. 相似文献
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Simple Zeros of the Riemann Zeta-Function 总被引:1,自引:0,他引:1
Assuming the Riemann Hypothesis, Montgomery showed by meansof his pair correlation method that at least two-thirds of thezeros of Riemann's zeta-function are simple. Later he and Taylorimproved this to 67.25 percent and, more recently, Cheer andGoldston increased the percentage to 67.2753. Here we proveby a new method that if the Riemann and Generalized LindelöofHypotheses hold, then at least 70.3704 percent of the zerosare simple and at least 84.5679 percent are distinct. Our methoduses mean value estimates for various functions defined by Dirichletseries sampled at the zeros of the Riemann zeta-function. 1991Mathematics Subject Classification: 11M26. 相似文献
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Quantum Zeno and anti-Zeno paradoxes 总被引:1,自引:0,他引:1
Continuous observation of a time independent projection operator is known to prevent change of state (the quantum Zeno paradox).
We discuss the recent result that generic continuous measurement of time dependent projection operators will in fact ensure
change of state: an anti-Zeno paradox. 相似文献
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粉粒体两相流的电容层析成象测量 总被引:4,自引:0,他引:4
粉粒体系统中的固相浓度分布的在线测量是十分困难的问题.电容层析成象技术是一种近年来发展起来的非侵入式快速浓度场测量技术.它不干扰流场,不受流动中颗粒浓度、加速度、不透明等因素的制约.本文讨论其测量原理、应用、近期进展、存在的主要问题及其解决的对策. 相似文献
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ac Conductivity measurements are carried out across the metal to insulator transition in NiAl0.7Cr0.7Fe0.6O4. The low frequency data is analyzed using Summerfield scaling theory for hopping conductivity. The exponent of the scaling
behavior has significantly different values in the conducting and insulating regimes. The hopping frequency and the zero frequency
conductivity are found to increase with temperature, slowly in the metallic regime and rapidly in the insulating regime. 相似文献