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Self‐suspended rare‐earth doped up‐conversion luminescent waveguide:propagating and directional radiation 被引量:3
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作者 Changjian Zhang Chengyun Zhang +6 位作者 Zhenglong Zhang Tao He Xiaohu Mi ting kong Zhengkun Fu Hairong Zheng Hongxing Xu 《Opto-Electronic Advances》 2020年第6期1-7,I0001,共8页
Near-infrared excited rare-earth(RE)-doped up-conversion(UC)-luminescent materials have attracted enormous attention because of their unique emission properties,such as narrow emission bands,long luminescence lifetime... Near-infrared excited rare-earth(RE)-doped up-conversion(UC)-luminescent materials have attracted enormous attention because of their unique emission properties,such as narrow emission bands,long luminescence lifetimes,and multiple colors.However,current development of RE-doped luminescent material is hindered by weak and narrowband absorption problems and low photon-conversion quantum efficiencies.In addition to conventional approaches to enhance fluorescence intensity,controlling emission directivity to improve detection efficiency has become a promising approach to obtain higher luminescence brightnesses.In this paper,a self-suspended RE-doped UC luminescent waveguide is designed to realize directional emissions.Benefitting from the special morphology of the crown-like NaYF4:Yb3+/Er3+microparticle,the points contact between the waveguide and substrate can be obtained to decrease energy loss.An attractive UC luminescent pattern accompanied by powerful and controllable directional emissions is observed,and the spatial emission angle and intensity distribution are explored and analyzed in detail by introducing Fourier imaging detection and simulation.This work provides a new method for achieving controllable directional fluorescence emissions and obtaining improved detection efficiency by narrowing emission directivity,which has potential applications in 3-dimensional displays and micro-optoelectronic devices,especially when fabricating self-fluorescence micron lasers. 展开更多
关键词 rare-earth-doped microcrystal UP-CONVERSION self-suspended Fourier imaging
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Research on Multi-Authority CP-ABE Access Control Model in Multicloud 被引量:3
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作者 Shengli Zhou Guangxuan Chen +2 位作者 Guangjie Huang Jin Shi ting kong 《China Communications》 SCIE CSCD 2020年第8期220-233,共14页
In order to solve the problems of data sharing security and policy conflict in multicloud storage systems(MCSS), this work designs an attribute mapping mechanism that extends ciphertext policy attribute-based encrypti... In order to solve the problems of data sharing security and policy conflict in multicloud storage systems(MCSS), this work designs an attribute mapping mechanism that extends ciphertext policy attribute-based encryption(CP-ABE), and proposes a multi-authority CP-ABE access control model that satisfies the need for multicloud storage access control. The mapping mechanism mainly involves the tree structure of CP-ABE and provides support for the types of attribute values. The framework and workflow of the model are described in detail. The effectiveness of the model is verified by building a simple prototype system, and the performance of the prototype system is analyzed. The results suggest that the proposed model is of theoretical and practical significance for access control research in MCSS. The CP-ABE has better performance in terms of computation time overhead than other models. 展开更多
关键词 CP-ABE access control multicloud multi-authority TRUST
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Oil geochemistry derived from the Qinjiatun–Qikeshu oilfields:insight from light hydrocarbons
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作者 Jin Li ting kong Min Zhang 《Acta Geochimica》 EI CAS CSCD 2018年第3期433-440,共8页
A suite of 27 oils from the Qinjiatun–Qikeshu oilfields in the Lishu Fault Depression of the Songliao Basin was analyzed using whole oil gas chromatography.In combination with the relative distribution of C27, C28,an... A suite of 27 oils from the Qinjiatun–Qikeshu oilfields in the Lishu Fault Depression of the Songliao Basin was analyzed using whole oil gas chromatography.In combination with the relative distribution of C27, C28,and C29 regular steranes, detailed geochemical analyses of light hydrocarbons in oil samples revealed crude oils characterized by the dual input of lower aquatic organisms and higher terrestrial plants. Several light hydrocarbon indicators suggest that the liquid hydrocarbons have maturities equivalent to vitrinite reflectances of around0.78%–0.93%. This is consistent with the maturity determination of steranes C2920 S/(20 S ? 20 R) and C29 aab/(aaa ? abb). Crude oils derived from the two distinct oilfields likely both have source rocks deposited in a lacustrine environment based on light hydrocarbon parameters and on higher molecular weight hydrocarbon parameters. The results show that light hydrocarbon data in crude oils can provide important information for understanding the geochemical characteristics of the Qinjiatun–Qikeshu oils during geologic evolution. 展开更多
关键词 Light hydrocarbons CRUDE OIL Lishu FaultDepression GEOCHEMISTRY characteristic
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