CERAMICS INTERNATIONAL
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2021
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IF 4.527
Yong-he Liu,Shun-kang Pan,Li-chun Cheng,Hua-yuan Yao,Yu-hang Zhai,Yu-cheng Chen
Manganese-based rare-earth perovskite oxides with excellent dielectric loss and effective magnetic loss have attracted considerable attention as microwave-absorbing materials. Herein, irregular spherical particles of Pr 1-x Ba x MnO 3 (x = 0, 0.02, 0.04, 0.06) were successfully designed and fabricated by a sol–gel combustion method. The Ba 2+ doping amount played a dominant role in adjusting the electromagnetic (EM) functions of the PrMnO 3 ceramics. X-ray diffraction and refinement results illustrated that Ba 2+ doping had no effect on the main phase of PrMnO 3 , but it caused lattice distortion and led to changes in the lattice constant of the material. The magnetisation curves did not reach saturation, and the materials had low coercivity at room temperature. Fluctuations in the Mn 4+ /Mn 3+ ratio due to oxygen vacancies decreased owing to the addition of Ba 2+ , as demonstrated by the X-ray photoelectron spectroscopy analysis. It was observed that the absorption of electromagnetic wave (EMW) energy could be effectively controlled by adjusting the Ba 2+ content. The Pr 0.98 Ba 0.02 MnO 3 sample exhibited the best EMW absorption ability; the minimum reflection loss (RL min ) was -46.45 dB (absorption rate of 99.99%), and the matching thickness was 3.7 mm. The maximum bandwidth of the Pr 0.98 Ba 0.02 MnO 3 sample was 6.16 GHz, while the thickness of the absorbing coating was only 2.5 mm. When d = 5.5 mm, Pr 0.94 Ba 0.06 MnO 3 achieved an RL of -18.97 dB at 5.04 GHz (C band). This shows that Pr 0.94 Ba 0.06 MnO 3 also has good microwave absorption ability in the low-frequency C band, and its RL peak conformed to the nλ/4 cancellation law at a given thickness. The results show that the low-cost sol–gel combustion synthesis process and lightweight, wideband, and strong absorption ability of Pr 1-x Ba x MnO 3 make it a promising candidate for microwave absorbers.
研究领域:
材料科学
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电磁学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
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2024
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IF 5.6
Yong-hong Niu,Zheng-yang Chi,Shuang Han,Ming Li,Feng-tao Han
Biomass is considered a renewable green coal, and its clean and efficient utilization is of great significance for energy conservation and carbon reduction. One of the most critical aspects of biomass gasification is the selection of an appropriate catalyst. In this study, we synthesized a catalyst with 10 % Pr 1-x Ce x CoO 3 supported on dolomite using the sol-gel method. We conducted graded internal circulation gasification experiments to produce hydrogen-rich syngas. The effects of element substitution in PrCoO 3 , temperature, catalyst composition, and steam injection rate on the products were investigated. The optimal gasification conditions were determined through response surface regression analysis. The data indicate that this catalyst can improve gasification efficiency, with Pr 0.4 Ce 0.6 CoO 3 /Dol showing the best catalytic performance. It effectively reduces the required gasification temperature and steam amount, decreases CO 2 production, and increases CO and H 2 yields. The catalyst accelerates the cleavage and ring-opening reactions of hydrocarbons, leading to terminal chain hydroxylation, followed by the dehydration-condensation of methyl groups into ethers. As the temperature rises, the rate of carboxyl group removal gradually exceeds the rate of carboxyl group formation via the oxidation of hydroxyl and ether chains, resulting in an initial increase and then a decrease in the number of carboxyl groups. Under optimal gasification conditions, CO 2 production is reduced by one-fourth compared to using a dolomite catalyst.
研究领域:
能源科学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2021
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IF 5.816
Yongyong Li,Lili Yang,Wenlu Li,Zhaoyu Hou,Caixia Shi,Guangjun Zhang,Juan Zhou,Shaorong Wang
A promising strontium and cobalt-free ferrite Pr 1-x Ca x FeO 3-δ (PCF, x = 0, 0.1, 0.2, 0.3, 0.4, 0.5) has been synthesized successfully by glycine-nitrate combustion method and used as the air electrode of solid oxide electrolysis cell (SOEC) for steam electrolysis. The crystal structure and electricity conductivity of PCF are investigated in detail. According to the conductivity test, Pr 0.6 Ca 0.4 FeO 3-δ (PCF64) with higher conductivity is selected as the air electrode to preparing the single cell with structure of PCF64|GDC|SSZ|YSZ-NiO. Under SOFC mode, the maximum power density of the single cell is 462.93 mW cm −2 at 800 °C with hydrogen as fuel. Under SOEC mode, the current density reaches 277.14 mA cm −2 and the corresponding hydrogen production rates is 115.84 mL cm −2 h −1 at 800 °C at 1.3 V. In the 10 h short-term stability test, the cell shows good electrolysis stability.
研究领域:
材料科学
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能源工程
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
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IF 4.7
Gaoqing Hang,Qiulei Li,Alberto José Fernández-Carrión,Sihao Deng,Lunhua He,Xiaojun Kuang,Xiaoyan Yang
Oxide-ion conductors based on tetrahedral anion-related oxides have attracted considerable attention due to their high oxygen-ion conductivity and potential applications in clean energy devices, such as solid-state fuel cells. In this study, we report the improvement of oxide-ion conductivity by Sr2+ doping in isolated tetrahedral zircon-type PrVO4. It is found that Pr0.975Sr0.025VO4−δ features the highest oxide-ion conductivity of 2.62 × 10–3 S·cm–1 at 800 °C under air, with an oxygen transport number of 0.93. The formation and stabilization of oxygen vacancy defects, as well as the oxide-ion migration mechanism in PrVO4, were investigated through combining experimental characterizations and computing simulations. The results indicate that the concentration of oxygen vacancy defects increases with Sr2+ substitution, and the vacancies are accommodated by the formation of corner-sharing V2O7 dimers. Oxygen-ion migration proceeds via a cooperative mechanism involving V2O7-dimer breaking and reforming assisted by synergistic rotation and deformation of neighboring VO4 tetrahedra. The results provide valuable insights for further investigation and optimization of zircon-type oxides as potential oxide-ion conductors for electrochemical devices.
研究领域:
材料科学
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固体离子学
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能源材料
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计算材料科学
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电化学器件
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
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2024
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IF 8.1
Wenjing Zhang,Yuan Gao,Jinke Zhang,Ao Zhao,Fangsheng Liu,Kun Zheng,Fangjun Jin,Yihan Ling
Solid oxide fuel cells (SOFCs) have received continuous attention as an energy conversion device, and the development of highly electrochemically active materials is important. In this work, highly active and CO 2 tolerant BaBi x Co 1-x O 3 @PrBaCo 2 O 5+δ heterostructure electrode materials were fabricated by a facile A-site deficiency in Pr 1-x BaCo 2 O 5+δ double perovskite . A-site excess-deficient Pr 0.8 BaCo 2 O 5+δ (PBC80) double-perovskite oxide were prepared and designed to induce the self-assembly dissolution to form BaCoO 3-δ (BCO) heterostructure through cationic high-concentration deficiency. However, the surface-dissolved alkaline earth metal (Ba 2+ ) readily forms carbonates with CO 2 , which severely limits the cathode catalytic activity and long-term stability. Thus, bismuth ion-modified PBC80 (BBCO@PBCO) was prepared to further tailor the material properties, which provides more active sites for oxygen reduction reaction (ORR) by strengthening the synergistic interaction between the heterogeneous interfaces. More importantly, BBCO@PBCO exhibits the most stable Area specific resistance (ASR) under CO 2 atmosphere, indicating the incorporation of acidic Bi ions effectively mitigated the adsorption and reaction between the material and the acidic gas CO 2 . These results indicate that the heterostructure induced by A-site deficiency promotes the ORR activity of PrBaCo 2 O 5+δ cathode, while further modification of Bi ions enhances both the electrochemical activity and the stability of the materials, delivering superior resistance to CO 2 poisoning.
研究领域:
材料科学
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电化学
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能源材料
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催化
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钙钛矿氧化物
✓ 已验证
DOI
高影响因子
DYES AND PIGMENTS
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2022
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IF 5.122
Jun Liu,Huizi Man,Chen Chang,Qingyue Liu,Quanda Yu,Shiyu Wang,Peng Yang,Yi Xiao,Mingzhe Liu
In this study, a fluorescent probe-encapsulated reduction-sensitive smart nanohydrogel as a new nanosensor was fabricated. The nanohydrogel was prepared via distillation-precipitation polymerization by using N, N ′-bis(acryloyl) cystinamide both as the monomer and crosslinker . Besides, red fluorescent hydrophobic peroxyresorufin-1 (PR1) probe for H 2 O 2 was employed and encapsulated into the nanohydrogel. We found that the nanohydrogel not only can encapsulate a large number of hydrophobic fluorescent probes with high loading capacity, but also can avoid the aggregation of hydrophobic fluorescent probes. Confocal laser fluorescence imaging of H 2 O 2 in HeLa cells demonstrated that the PR1-encapsulated nanohydrogel allows efficient delivery of PR1 probe into living HeLa cells. In cytoplasm, the nanohydrogels reduced and degraded by glutathione, and the PR1 probes released from the nanohydrogel were enriched and concentrated in some local regions, resulting in enhanced imaging of endogenous H 2 O 2 . This work provides a facile nanohydrogel-assisted probe-encapsulation strategy, which is also applicable to multiple fluorescent probes, thus enabling imaging of diverse endogenous bioactive molecules .
研究领域:
纳米技术
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生物医学工程
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分析化学
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细胞生物学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2023
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IF 8.2
Yao Wang,Liang Yang,Xiao Zhou,Ye Wang,Yijia Liang,Binshao Luo,Yuhao Dai,Zhouling Wei,Shili Li,Rong He,Wei Ding
The exploration of biopolymer-based materials to avoid hazardous chemicals in agriculture has gained enormous importance for sustainable crop protection. Due to its good biocompatibility and water solubility, carboxymethyl chitosan (CMCS) has been widely applied as a pesticide carrier biomaterial. However, the mechanism by which carboxymethyl chitosan-grafted natural product nanoparticles induce tobacco systemic resistance against bacterial wilt remains largely unknown. In this study, water-soluble CMCS-grafted daphnetin (DA) nanoparticles ( [email protected] ) were successfully synthesized, characterized, and assessed for the first time. The grafting rate of DA in CMCS was 10.05 %, and the water solubility was increased. In addition, [email protected] significantly increased the activities of CAT, PPO and SOD defense enzymes, activated the expression of PR1 and NPR1 , and suppressed the expression of JAZ3 . [email protected] could induce immune responses against R. solanacearum in tobacco, including increases in defense enzymes and overexpression of pathogenesis-related (PR) proteins. The application of [email protected] effectively suppressed the development of tobacco bacterial wilt in pot experiments, and the control efficiency was as high as 74.23 %, 67.80 %, 61.67 % at 8, 10, and 12 days after inoculation. Additionally, [email protected] has excellent biosafety. Therefore, this study highlighted the application of [email protected] in manipulating tobacco to generate defense responses against R. solanacearum , which can be attributed to systemic resistance.
研究领域:
植物科学
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农业生物技术
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纳米技术
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植物病理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY
·
2023
·
IF 4.7
Yueyang Zhang,Yue Jiang,Yina Jia,Xiaoyu Pan,Tianrun Zhao,Kaiyue Wang,He Yan,Zhiqing Ma
Background Omphalia lapidescens is a saprophytic and parasitic fungus belonging to the Polypora genus of Tricholomataceae . It has repellent, insecticidal, anti-inflammatory and immunomodulatory effects. Result This study found that the extract of O. lapidescens had significant anti-TMV activity, and the main active component was homopolysaccharide LW-1 by Bioassay-guided fractionation. LW-1 is a glucan with β-(1,3) glucoside bond as the main chain and β-(1,6) glucoside bond as the branch chain, with molecular weight in the range of 172,916–338,827 Da. The protective and inactive efficacies of LW-1(100 mg/L) against TMV were 78.10% and 48.20%, but had no direct effect on the morphology of TMV particles. The results of mechanism of action showed that LW-1 induced the increase of the activity of defense enzymes such as POD, SOD and PAL in Nicotiana glutinosa . The overexpression of resistance genes such as NPR1, PR1 and PR5 , and the increase of SA content. Further transcriptome sequencing showed that LW-1 activated MAPK signaling pathway, plant-pathogen interaction pathway and glucosinolide metabolic pathway in Arabidopsis thaliana . Besides, LW-1 induced crops resistance against plant pathogenic fungi. Conclusion Taken together, the anti-TMV mechanism of LW-1 was to activate MAPK signaling pathway, inducing overexpression of resistance genes, activating plant immune system, and improving the synthesis and accumulation of plant defencins such as glucosinolide. LW-1-induced plant disease resistance has the advantages of broad spectrum and long duration, which has the potential to be developed as a new antiviral agent or plant immune resistance inducer.
研究领域:
植物病理学
·
分子生物学
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植物化学
·
免疫学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）