MATERIALS RESEARCH BULLETIN
·
2024
·
IF 5.3
Haixia Zheng,Xianju Zhou,Siyu Li,Li Li,Yan Deng,Jiaju Huang,Yan Yan
A series of MgMoO 4 : x%Er 3+ ( x = 0, 1, 2, 3, 4, 5) phosphors were synthesized by high temperature solid-state reaction. The doping concentration of Er 3+ was optimized, and the thermometric properties of the phosphors were investigated based on the thermally coupled energy levels of Er 3+ ( 2 H 11/2 and 4 S 3/2 ) via the luminescence intensity ratio (LIR) technology. The absolute sensitivity (S A ) and relative sensitivity (S R ) of the samples were investigated with the maximum S R being 0.83% K −1 . To maintain the electrical neutrality of the phosphors and reduce lattice distortion of the hosts, a certain amount of charge compensators (Li + , Na + , K + ) were introduced into the phosphors. The luminescent intensity of the phosphors was enhanced greatly, and the thermometric properties were improved slightly with the maximum S R at 0.89% K −1 by the charge compensators.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Xingye Zeng,Cunhui Lin,Qinggang Ren,Shufeng Shan,Hanlu Wang
Developing a highly efficient catalyst is one of the important topics in the field of oxidative desulfurization from liquid fuels. In this study, the composite metal oxide catalysts (CuO-MgO) with co-catalyst MgMoO 4 were prepared by co-precipitation method with simple process, high efficiency and good performance and their structures characterized. An efficient extractive catalytic oxidative desulfurization (ECODS) system for liquid fuel was successfully developed on the basis of as-prepared CuO-MgO-MgMoO 4 (CuMgMo) as the catalyst, sodium hypochlorite (NaClO) as the oxidant, and acetonitrile as the extractant. Taking the n -decane and n -tetradecane containing dibenzothiophene (DBT) as the test model oil sample, the main parameters influencing desulfurization performance were examined in detail, such as the molybdenum content, the dosage of CuMgMo, the reaction temperature, the initial S-concentration, the different extractants, the volume ratio of extractant to oil, the different oxidants, and the molar ratio of NaClO to DBT . Based on optimized desulfurization reaction conditions, the model oil containing different sulfur compounds (benzothiophene, 4-methyldibenzothiophene, and 4,6-dimethyldibenzothiophene) and the real oil (straight-run gasoline, straight-run kerosene, and straight-run diesel) were further tested. Based on the free radical trapping experiments and the calculation of density functional theory, the reaction mechanism was deeply explored. The results showed that the de-electron reaction of DBT was mainly catalyzed by MgMoO 4 and the reaction of HClO obtaining electron was mainly catalyzed by CuO. MgMoO 4 plays an assisting role in improving the catalytic reaction rate. This work will provide a useful reference for the construction of efficient ECODS system using composite metal oxides.
研究领域:
化学工程
·
催化材料
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2023
·Vol. 107
·期 2
·1033-1041
·
IF 3.9
Xiaoyu Li,Hongye Wang,Xinwei Xu,Naichao Chen,Biao Guo,Jin Cheng,Xianqiang Chen,Hong Wang
The MgO-MoO 3 system shows significant potential for applications in microwave dielectric ceramics. However, the formation mechanism, crystal structures, and microwave dielectric properties of this system have not been systematically investigated. This work aims to comprehensively study the crystal structures, phase transitions, and microwave dielectric properties of compounds in the MgO-MoO 3 system. In particular, the research delves into the unexplored transformation mechanism from β-MgMo 2 O 7 to α-MgMo 2 O 7 and MgMoO 4 . As a result, the three compounds exhibiting favorable microwave dielectric properties have been successfully fabricated. These compounds can be effectively sintered at temperatures ranging from 685 to 900°C and exhibited dielectric constants (ε r ) ranging from 5.41 to 6.89, as well as Qf values ranging from 100 000 to 130 000 GHz. Additionally, prototype microstrip antennas are designed and fabricated using β-MgMo 2 O 7 and MgMoO 4 ceramics as substrates. The obtained antenna's performance is excellent, with S 11 values below −30 dB and a gain exceeding 6 dB at 5.8 GHz, highlighting the potential of the developed ceramics for practical applications in microwave devices.
研究领域:
材料科学
·
陶瓷工程
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2026
·
IF 6
Fei Xie,Mingwei Zhang,Le Xin,Shuzhi Zhang,Luchao Ren,Hui Peng,Panpan Lyu,Cuncheng Li,Jiwei Zhai
Herein, Mg 1- x Cu x MoO 4 (0≤ x ≤0.1) ceramics were synthesized via solid-state reaction for low-temperature co-fired ceramic (LTCC) applications. The effects of Cu 2+ substitution on phase evolution, microstructure, and microwave dielectric properties were systematically investigated. Cu 2+ incorporation, driven by Jahn-Teller distortion, induced a phase transition from monoclinic β -MgMoO 4 to triclinic α -MgMoO 4 , accompanied by a sequential process of solid-solution formation, phase transformation, and secondary-phase precipitation. Enhanced performance is attributed to liquid-phase sintering, lattice distortion-induced bond reconstruction, and reduced intrinsic loss from vibration mode splitting. Optimum microwave dielectric properties were obtained for the composition Mg 0.94 Cu 0.06 MoO 4 sintered at 800 °C for 6 h, ε r =6.86, Q× f =29,400 GHz, and τ f =-60.97 ppm/°C.
✓ 已验证
DOI
高影响因子
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