JOURNAL OF LUMINESCENCE
·
2022
·
IF 4.171
Zuodong Liu,Qilong Shen,Yue Cao,Siya Li,Xue Chen,Jiashun Wang,Yongsheng Yu,Bingchu Mei,Qiangshan Jing,Peng Liu
Pr, La:SrF 2 ceramics co-doped with various amounts of LaF 3 were fabricated by hot-pressing (HP) sintering in a vacuum environment. The transmittance of the Pr, La:SrF 2 ceramics was gradually improved with the increase in sintering temperature , and the sintering temperature of 1000 °C was adequate to fabricate highly transparent ceramics without rapid grain growth. Residual pores and undissolved PrF 3 /LaF 3 fluorides were identified as light scattering defects within the ceramic sintered at 830 °C. The effect of LaF 3 on the microstructural, transmittance, and spectroscopic characteristics of ceramics was studied systematically. The luminescence intensity of the Pr, La:SrF 2 ceramics was drastically enhanced through LaF 3 co-doping, while the optical transmittance first slightly increased and then decreased. The ceramic sample co-doped with 1 wt% LaF 3 exhibits the highest transmittance with the smallest grain size of 43.4 μm, and the transmittance reaches 87.8% at 400 nm and 87.2% at 1100 nm.
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高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Zhuoyi Zhang,Yunshuo Wu,Yuxin Sun,Haiqiang Wang,Zhongbiao Wu,Xuanhao Wu
Nitrous oxide (N2O) is a potent greenhouse gas with a high global warming potential. The N2O direct decomposition (deN2O) is currently the most widely used technique due to its operational simplicity and lack of secondary pollution. The presence of impurity gases in industrial exhaust increases the challenge of eliminating N2O, urging the development of highly active and stable catalysts for its degradation. In this study, a series of praseodymium (Pr)-doped nickel oxide (NiO) catalysts were synthesized for N2O degradation. These catalysts showed higher N2O decomposition activity (T100 = 400–440 °C) than pure NiO (T100 = 480 °C) and also demonstrated high resistance to impurity gases in simulated industrial nitric acid tail gas. In the catalyst with a Pr to Ni ratio of 0.002, the highly dispersed Pr on the NiO surface regulated its particle size and increased specific surface area and pore volume. DFT calculations revealed that Pr significantly enhanced the electron-donating ability of Ni2+, facilitating the dissociative adsorption of N2O on the catalyst surface, where O existed in the form of Ni3+-O*. Additionally, Pr reduced the desorption energy of O2, the rate-determining step. During the reaction, Pr3+ transferred electrons to Ni3+ via f-d electron hopping, stabilizing the active Ni2+ sites and enabling an efficient catalytic reaction. These findings demonstrate the practical potential of this catalyst and provide new insights into the degradation of N2O in industrial exhaust gases, offering a promising avenue for application.
研究领域:
环境科学
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催化化学
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高影响因子
Processes
·
2021
·Vol. 9
·期 2
·400
·
IF 2.847
Xiaohua Cao,Jichang Lu,Yutong Zhao,Rui Tian,Wenjun Zhang,Dedong He,Yongming Luo
Praseodymium (Pr)-promoted MCM-41 catalyst was investigated for the catalytic decomposition of methyl mercaptan (CH3SH). Various characterization techniques, such as X-ray diffraction (XRD), N2adsorption–desorption, temperature-programmed desorption of ammonia (NH3-TPD) and carbon dioxide (CO2-TPD), hydrogen temperature-programmed reduction (H2-TPR), and X-ray photoelectron spectrometer (XPS), were carried out to analyze the physicochemical properties of material. XPS characterization results showed that praseodymium was presented on the modified catalyst in the form of praseodymium oxide species, which can react with coke deposit to prolong the catalytic stability until 120 h. Meanwhile, the strong acid sites were proved to be the main active center over the 10% Pr/MCM-41 catalyst by NH3-TPD results during the catalytic elimination of methyl mercaptan. The possible reaction mechanism was proposed by analyzing the product distribution results. The final products were mainly small-molecule products, such as methane (CH4) and hydrogen sulfide (H2S). Dimethyl sulfide (CH3SCH3) was a reaction intermediate during the reaction. Therefore, this work contributes to the understanding of the reaction process of catalytic decomposition methyl mercaptan and the design of anti-carbon deposition catalysts.Keywords:rare earth;MCM-41;CH3SH decomposition;stability;reaction mechanism
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高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2021
·Vol. 45
·期 6
·8577-8592
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IF 5.164
Wei Han,Wei Wang,Yongqiang Zhang,Yijie Wang,Mei Li,Yang Sun
Summary To recover Pr from molten chlorides, the electrode reactions of Pr 3+ on Sn-coated W and liquid Sn electrodes were studied by a group of electrochemical techniques. CV and SWV results exhibited that the electrochemical signals pertaining to the formation of Pr-Sn alloy compounds and solid solution appeared at less negative potentials than that of Pr 3+ on W electrode. The thermodynamic data of Pr-Sn alloy compounds and the kinetic parameters for PrSn 3 /Pr 3+ pair were determined employing OCP, LP, and Tafel methods, separately. The measured diffusion coefficient ( D ) of Pr in liquid Sn metal was 9.40 × 10 −6 cm 2 s −1 . Furthermore, the electrochemical recovering Pr from molten salt was performed using liquid Sn as a working electrode, and the formed Pr-Sn samples characterized by XRD and SEM-EDS were composed of Sn and PrSn 3 phases.
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高影响因子
ACS Applied Materials & Interfaces
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2021
·
IF 9.229
Lei Jiang,Miguel Tinoco,Susana Fernández-García,Yujiao Sun,Mariia Traviankina,Pengli Nan,Qi Xue,Huiyan Pan,Almudena Aguinaco,Juan M. González-Leal,Ginesa Blanco,Eduardo Blanco,Ana B. Hungría,Jose J. Calvino,Xiaowei Chen
In this work, a simple one-step thermal oxidation process was established to achieve a significant surface increase in {110} and {111} nanofacets on well-defined, pure and Pr-doped, ceria nanocubes. More importantly, without changing most of the bulk properties, this treatment leads to a remarkable boost of their enzymatic activities: from the oxidant (oxidase-like) to antioxidant (hydroxyl radical scavenging) as well as the paraoxon degradation (phosphatase-like) activities. Such performance improvement might be due to the thermally generated sawtoothlike {111} nanofacets and defects, which facilitate the oxygen mobility and the formation of oxygen vacancies on the surface. Finally, possible mechanisms of nanoceria as artificial enzymes have been proposed in this manuscript. Considering the potential application of ceria as artificial enzymes, this thermal treatment may enable the future design of highly efficient nanozymes without changing the bulk composition.
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PubMed
高影响因子
Cells
·
2024
·Vol. 13
·期 3
·206
·
IF 5.1
Meng-Yuan Li,Ying Wang,Ying Wu,Xu-Yu Zhao,Zhen-Shan Yang,Bo Li,Si-Ting Chen,Yu-Ying He,Zeng-Ming Yang
(1) Background: Inflammatory responses are implicated in embryo implantation, decidualization, pregnancy maintenance and labor. Both embryo implantation and decidualization are essential to successful pregnancy in rodents and primates. S100A6 is involved in inflammation, tumor development, apoptosis and calcium homeostasis. S100A6 is strongly expressed in mouse decidua, but the underlying mechanisms of how S100A6 regulates implantation and decidualization are poorly defined. (2) Methods: Mouse endometrial stromal and epithelial cells are isolated from day 4 pseudopregnant mouse uteri. Both immunofluorescence and Western blotting are used to analyze the expression and localization of proteins. The molecular mechanism is verified in vitro by Western blotting and the quantitative polymerase chain reaction. (3) Results: From days 4 to 8 of pregnancy, S100A6 is specifically expressed in mouse subluminal stromal cells. Blastocyst-derived lactic acid induces AA secretion by activating the luminal epithelial p-cPLA2. The epithelial AA induces stromal S100A6 expression through the COX2/PGI2/PPAR δ pathway. Progesterone regulates S100A6 expression through the progesterone receptor (PR). S100A6/RAGE signaling can regulate decidualization via EGFR/ERK1/2 in vitro. (4) Conclusions: S100A6, as an inflammatory mediator, is important for mouse implantation and decidualization.Keywords:decidualization;implantation;S100A6;RAGE;inflammation
研究领域:
生殖生物学
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分子生物学
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免疫学
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PubMed
高影响因子
Inorganic Chemistry Frontiers
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2025
·
IF 6.4
W. Y. Li,C. Y. Li,Z. H. Xu,W. B. Dai
Various optical signals are popularly harnessed to realize anticounterfeiting, encryption, and photoluminescence (PL)-based sensing. However, most phosphors can only achieve single PL output under a fixed excitation, thus simultaneous attainment of multimodal PL behaviors remains an imperative pursuit. Herein, a highly integrated multimodal photon-, temperature-, and mechanically responsive Sr2Ga2SiO7:Zn2+/Er3+/Pr3+(SGS:Zn/Er/Pr) is designed/synthesized via a facile solid-state reaction, endowing tunable down/up-converted (DC/UC) PL, mechanoluminescence (ML), and long-persistent PL (LPL) owing to the synergistic effects of self-activated and dopant-induced electronic transitions. serves as both an emitter and a trap center for the self-(L)PL located at ∼468 nm under λex = 267 nm. These behaviors are further optimized by adjusting the content of and by forming a bridge () between trap levels upon Zn2+ incorporation. The excitation and Zn2+ content-dependent PL can be modified from blue to cyan via conflating dual self-PL from the 4T1 → 4A1 transition of Ga3+ at ∼402 nm and . The green DC/red UC PL from Er3+is observed under λex = 357 and 980 nm, respectively. Nonequivalent substitution of Pr3+ at the Sr2+site and the incorporation of Zn2+ can adjust the charge transfer band energy level position and optimize the trap distribution, achieving long-term storage and highly repeatable/efficient LPL/ML generation. Based on abundant PL multimodes, the single-phased SGS:Zn/Er/Pr shows promising applications in sophisticated anticounterfeiting and latent fingerprint detection. Concurrently, owing to the coupled energy levels 2H11/2/4S3/2 of Er3+and the pressure-dependent ML of Pr3+, the SGS:Zn/Er/Pr is also suitably applied as a temperature/stress sensing agent.
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高影响因子
JOURNAL OF ELECTRONIC MATERIALS
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2022
·Vol. 51
·期 3
·1180-1188
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IF 2.047
Ji Xinran,Zhou Ke,Zhao Ye,Sun Meiling,Dong Shijun,Zhang Hongbo,Cao Hechun,Zheng Hui,Wu Qiong,Zhang Yang
The regulation of magnetic and dielectric properties for yttrium iron garnet ferrites by ion doping is highly desirable in microwave devices. In this work, yttrium iron garnet ferrites co-doped with Pr-Zn-Zr atoms with the chemical formula Pr x Y 3-x Zn 0.1 Zr 0.1 Fe 4.8 O 12 (x = 0, 0.1, 0.15, and 0.2) were prepared. The dependence of the crystal structure, microstructure, magnetic, and dielectric properties of the obtained samples on the Pr doping concentration was investigated. The morphologies and crystal structure characterizations confirm that the Pr ion has effectively doped in the yttrium iron garnet ferrites and increased the lattice parameter and grain size. The magnetic characterization shows that the saturation magnetization also increases with the Pr concentration and obtains a maximum value of 27.68 emu/g at x = 0.15. Additionally, the doping of Pr increases the magnetic anisotropy constant K 1 which increases ferromagnetic resonance linewidth. Lastly, the dielectric properties measurement further indicates that Pr doping improves both real and imaginary parts of permittivity, and the highest value of the real part of the permittivity is obtained at x = 0.15. Consequently, the crystal structure, microstructure, magnetic properties, and dielectric properties of garnet ferrite can be effectively regulated by the Pr doping concentration, and excellent properties of the ceramic can be obtained at x = 0.15, which allows potential applications in microwave devices.
研究领域:
材料科学
·
物理学
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高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Jinyang Li,Wenye Deng,Yan Xue,Ni Ai,Kai Ding,Xianghui Chen,Pengjun Zhao,Aimin Chang,Yongxin Xie
This study used the solid-phase method to prepare thermosensitive perovskite ceramics, La 0.9 B 0.1 AlO 3 (B = Pr, Nd, Sm). The XRD and EDS results indicated that all components presented a single phase and all elements were uniformly distributed, formed a good solid solution. The SEM results clearly illustrated that the doped elements had enhanced the surface morphology, resulting in more uniform grain formation. The TEM results showed that linear defects were present, which led to an uneven stress distribution; consequently, this enhanced the carrier transport. The alternating current (AC) impedance showed that the grain boundary resistance determined the overall complex impedance and exhibited a different conductive mechanism with increasing temperature, from polariton to ion conduction. With the introduction of Nd 3+ , the conductivity of La 0.9 Nd 0.1 AlO 3 increased and its temperature range increased from 600 – 1400 °C to 100–1500 °C. In La 0.9 Sm 0.1 AlO 3 , the presence of Sm 2+ enhances the aging stability by elevating the oxygen vacancy concentration and the aging drift rate (ΔR/R0) was found to be lower than 2 %. In addition, DFT-based calculations were performed to investigate the property changes in the crystal structure and energy band structure of pure and doped LaAlO 3 . This study demonstrated an effective way to improve the performance of high-temperature thermistor materials using different doping strategies.
研究领域:
材料科学
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陶瓷
·
电子陶瓷
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固体化学
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计算材料科学
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高影响因子
COMPOSITES PART B-ENGINEERING
·
2025
·
IF 14.2
Wei Wang,Ruixiang Liu,Xiangyu Jin,Gu Liu,Jiaxin Zheng,Changqing Hong,Xinghong Zhang
The pronounced oxidative degradation and substantial ablation recession of traditional lightweight ablative materials in low-altitude, medium-to-high temperature service environments highlight a critical deficiency, underscoring the urgent need for novel, high-performance ablation-resistant thermal protection systems. Herein, we utilize in-situ chemical grafting principles combined with sol-gel processes to develop a ceramic fiber matrix material system. The bending strength of MFC reached 7.7 MPa; the compressive strengths in Z direction and XY direction were 4.0 MPa and 9.03 MPa, respectively, due to the confining effect of the SiPRA. The thermal conductivity of MFC was 0.031–0.051 W/(m·K). More importantly, the increased fiber content reduced the effective heat release of MFC, demonstrating outstanding ablation-resistant thermal insulation properties. After repeated testing (1300°C-1800 s/cycle), the backside temperature was 188.2–218.9 °C, with zero ablation retreat; under short-term aerodynamic conditions at 1750 °C, the backside surface temperature ranges from 122.6 to 134.3 °C, with a linear ablation rate as low as 0.021 mm/s. MFC is an ideal choice for thermal protection systems in hypersonic spacecraft, and near-space vehicles.
研究领域:
材料科学
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航空航天工程
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热防护系统
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陶瓷复合材料
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高温材料
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高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
M. Yousaf,Majid Niaz Akhtar,Baoyuan Wang,Asma Noor
Rare earths RE's (Pr, Y, Gd, Ho, Yb) substituted MnZn spinel ferrites with composition of Mn 0.5 Zn 0.5 M 0.02 Fe 1.98 O 4 (M = Pr, Y, Gd, Ho, Yb) are prepared by sol gel combustion approach. Low sintering temperature (500 °C) is used to sinter the RE's doped MnZn samples. MnZn samples are further characterized by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) to measure the cubic crystalline structure, particle size, morphology, porosity and grain size. Cubic crystalline phase of prepared RE's doped MnZn ferrites is confirmed by x-ray diffraction (XRD). The morphology, porosity and grain size are observed using FESEM. The magnetic properties of RE's doped MnZn nanoferrites are analyzed by vibrating sample magnetometer (VSM). Coercivity (H c ), remanence (M r ) and saturation magnetization (M s ) are calculated from the magnetic loops. The saturation and remanence of the nanoferrites are increased by the substitution of RE's metal ions and varies from 14.76 to 26.36 emu/g and 9.98–22.48 emu/g respectively. Bohr magneton and anisotropy constant are calculated from the recorded magnetic data. The conductive analysis of the prepared samples is studied at 40 °C −300 °C temperature, leading to the conductivity measurements from 1.12 × 10 -2 Ω -1 -cm -1 to 9.52 × 10 -2 Ω -1 -cm -1 . UV–Vis spectroscopy is used to determine the semi conducting nature of RE's doped MnZn spinel ferrite samples. The magnetic, conductive and optical study of the RE's doped MnZn nanoferrites sintered at low temperature suggests the use of these materials for microwave absorption, supercapacitor , lithium ion batteries and nanoelectronics industrial applications.
研究领域:
材料科学
·
物理学
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高影响因子
Journal of Physical Chemistry Letters
·
2023
·
IF 5.7
Cheng Wang,Mingxue Deng,Yanfeng Tang,Tongming Sun,Minmin Wang,Jin Wang,Zhenzhen Zhou,Jiacheng Wang
Ultraviolet C (UVC) sterilization has the advantages of high efficiency, broad spectrum, and no secondary pollution. However, the emission wavelength of UVC phosphors still suffers from a large deviation from the golden sterilization wavelength of 265 nm and a low luminescence intensity. Herein, we report UVC emission near the golden sterilization wavelength as well as a long afterglow through crystal field engineering, which can lead to 100% sterilization efficiency. Combined with theoretical calculation and experimental studies, substitution of Ca2+ with large-sized Sr2+ could obtain slight expansion and distortion of cationic sites, resulting in a decrease in crystal field intensity and blue shift of Ca1.5Sr0.5Al2SiO7:1%Pr3+, and produce near golden UVC emission. Ca1.5Sr0.5Al2SiO7:1%Pr3+ phosphor can effectively inactivate Staphylococcus aureus within 10 min, showing more efficiency than the traditional mercury lamp. This work provides an effective solution for the design and preparation of UVC phosphors using crystal field engineering toward near golden UVC emission.
研究领域:
材料科学
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发光材料
·
光学工程
·
杀菌技术
·
固态化学
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DOI
高影响因子
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