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Exploring the electromagnetic shielding behavior of lanthanum doped calcium nanoferrites

Journal of Rare Earths 2024年第11期42卷 2128-2136页

作者： E.Ahilandeswari K.Sakthipandi R.Rajesh Kanna G.Rajkumar B.Ganesh Babu S.Arunmetha Aslam Hossain P.Sakthivel V.Rajendran M.Srinidhi Raghavan Department of Physics SRM TRP Engineering College Department of Electronics and Communication engineering M. Kumarasamy College of Engineering Department of Physics Easwari Engineering College Department of Mechanical engineering SRM TRP Engineering College centre for Advanced Energy Studies Department of Electronics and Communication EngineeringKoneru Lakshmaiah Education Foundation Smart materials Research Institute Southern Federal University centre for materials Science Department of PhysicsScience and HumanitiesFaculty of EngineeringKarpagam Academy of Higher Education centre for Nanotechnology Academy of Maritime Education and Training (Deemed to be University) Department of Chemistry and centre for Nano-materials and Displays B.M.S. College of Engineering

The present study focuses on the synthesis and characterization of lanthanum(La3+)-doped calcium nanoferrites(CaLaxFe2-xO4:x=0.025,0.050,0.075 and 0.100) using the sonochemical *** techniques were employed to analyze the effect of La3+infusion,Raman spectroscopy confirms the presence of active A1g,T2gand Egmodes in the CaLaxFe2-xO4nanoferrite,indicating the formation of an active ferrite *** introduction of La3+doping results in a significant increase in the band gap energy,rendering the nanoferrites insulating（3.23-3,57 eV）.At higher frequencies,the impedance studies reveal minimal losses and better AC conductivity,pointing to improved dielectric *** higher frequencies,the Q-factor of La-doped calcium nanoferrites shows lower electromagnetic *** M-H curve exhibits ferromagnetic behavior,with La3+-doped calcium nano ferrites displaying a saturation magnetization ranging from 12.72 to 18.10 emu/*** incorporation of La3+also induces enhanced electrical polarization,leading to notable dielectric loss and increased absorption of electromagnetic ***,these CaLaxFe2-xO4nanoferrites demonstrate potential as effective microwave absorbers across a wide frequency range,with significant shielding absorption observed at 8.8-9.1 GHz.

关键词： Dielectric Magnetism Microwave absorption Nanoferrites Rare earths Structural properties

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Designed imidazole-based supramolecular catalysts for accelerating oxidation/hydrolysis cascade reactions

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Nano Research 2024年第6期17卷 4916-4923页

作者： Yuanxi Liu Wenjie Xu Shichao Xu Haifeng Wu Baoli Zhang Li Song Zhen-Gang Wang State Key Laboratory of Organic-Inorganic Composites Key Lab of Biomedical Materials of Natural Macromolecules(Ministry of Education)Beijing Laboratory of Biomedical MaterialsCollege of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China National Synchrotron Radiation Laboratory CAS Center for Excellence in NanoscienceUniversity of Science and Technology of ChinaHefei 230029China

Reconstructing enzymatic active sites presents a significant challenge due to the intricacies involved in achieving enzyme-like scaffold folding and spatial arrangement of essential functional *** is also a growing interest in building biocatalytic networks,wherein multiple enzymatic active sites are localized within a single artificial system,allowing for cascaded *** this work,we report the self-assembly of imidazole or its derivatives with fluorenylmethyloxycarbonyl-modified histidine and Cu2+to fabricate a supramolecular catalyst,which possesses catechol oxidase-like dicopper center with multiple imidazole as the coordination *** electron microscopy,low-temperature X-band continuous-wave electron paramagnetic resonance,K-edge X-ray absorption spectra/the extended X-ray absorption fine structure analysis,and density functional theory modeling were used for the structural characterization of the *** phenol derivatives and the dissolved oxygen were used as the substrates,with the addition of 4-aminoantipyrine to generate a red adduct with a maximum absorbance at 510 nm,for obtaining time-dependent absorbance change curves and estimating the *** results reveal that the addition of imidazole synergistically accelerates the oxidative activity about 10-fold and the hydrolysis activity about 14-fold than fluorenylmethyloxycarbonyl modified-histidine/Cu2+.The supramolecular nanoassembly also exhibits the ability to catalyze oxidation/hydrolysis cascade reactions,converting 2′,7′-dichlorofluorescin diacetate into 2′,7′-*** process can be regulated through the methylation of the imidazole component at various *** work may contribute to the design of advanced biomimetic catalysts,and shed light on early structural models of the active sites of the primitive copper-dependent enzymes.

关键词： enzyme mimic self-assembly supramolecular catalyst cascade reactions

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Selective photosynthesis of Z-olefins through crystalline metal-organic cage-initiated expeditious cascade reactions

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Carbon Energy 2024年第3期6卷 118-131页

作者： Jia-Ni Lu Yunze Huang Yuan-Sheng Xia Long-Zhang Dong Lei Zhang Jing-Jing Liu Lan-Gui Xie Jiang Liu Ya-Qian Lan Jiangsu Key Laboratory of New Power Batteries School of Chemistry and Materials ScienceJiangsu Collaborative Innovation Centre of Biomedical Functional MaterialsNanjing Normal UniversityNanjingChina School of Chemistry South China Normal UniversityGuangzhouChina

The semi-hydrogenation of alkyne to form Z-olefins with high conversion and high selectivity is still a huge challenge in the chemical ***,flammable and explosive hydrogen as the common hydrogen source of this reaction increases the cost and danger of industrial ***,we connect the photocatalytic hydrogen evolution reaction and the semihydrogenation reaction of alkynes in series and successfully realize the high selective production of Z-alkenes using low-cost,safe,and green water as the proton *** the cascade reaction,a series of isomorphic metal–organic cage catalysts(Co_(x)Zn_(8−x)L_(6),x=0,3,4,5,and 8)are designed and synthesized to improve the yield of the photocatalytic hydrogen *** them,Co_(5)Zn_(3)L_(6) shows the highest photocatalytic activity,with a H_(2) generation rate of 8.81 mmol g^(−1) h^(−1).Then,Co_(5)Zn_(3)L_(6) is further applied in the above tandem reaction to efficiently reduce alkynes to Z-alkenes under ambient conditions,which can reach high conversion of>98%and high selectivity of>99%,and maintain original catalytic activity after multiple ***“one-pot”tandem reaction can achieve a highly selective and safe stepwise conversion from water into hydrogen into Z-olefins under mild reaction conditions.

关键词： alkyne semi-hydrogenation hydrogen evolution reaction metal-organic cages photocatalysis Z-olefins

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Screening for Bioactive Compounds from Mulberry Leaves Combining Bio-Affinity Ultrafiltration with α-Glucosidase and Pancreatic Lipase

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Journal of Analysis and Testing 2024年第3期8卷 315-326页

作者： Hui Zhang Guilin Chen Yongli Zhang Felix Wambua Muema Jun Ding Mingquan Guo CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical Garden Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of biomedical engineering Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences Ningbo Cixi Institute of biomedical engineering

With the growing prevalence of diabetes and obesity worldwide, the role of α-glucosidase and lipase inhibitors has gained increasing concentration. Mulberry, a functional medicinal and edible plant, has been reported extensively in alleviating both diabetes and obesity. However, there is still a lack of refined research on its active ingredients and mechanisms. In our study, the inhibitory activities of mulberry leaf against α-glucosidase and pancreatic lipase reached 191.37 ± 14.46 and 775 ± 68.60 μg/mL, respectively. Meanwhile, it also promoted glucose consumption in the HepG2 cells model. Subsequently,four α-glucosidase ligands and four pancreatic lipase ligands were identified through bio-affinity ultrafiltration combined with liquid-chromatography-mass spectrometry(UF-HPLC–MS/MS). In vitro inhibition assays confirmed the inhibitory potential of these representative ligands. Molecular docking suggested that these possible ligands could be inserted into the active pocket of the target enzyme through multiple intermolecular forces. Our findings indicated that the polyphenols in mulberry leaves may contribute significantly to their hypoglycemic and hypolipidemic properties. Furthermore, our study provides valuable insights for the screening of active ingredients in other medicinal and edible plants, which could help in the development of new therapies for diabetes and obesity.

关键词： Bio-affinity ultrafiltration Diabetes Mulberry leaves Obesity

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Mussel-inspired Methacrylic Gelatin-dopamine/Ag Nanoparticles/Graphene Oxide Hydrogels with Improved Adhesive and Antibacterial Properties for Applications as Wound Dressings

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Journal of Wuhan University of Technology(materials Science) 2024年第2期39卷 512-521页

作者：宿正楠 HU Yanru MENG Lihui OUYANG Zhiyuan LI Wenchao ZHU Fang XIE Bin 吴庆知 State Key Laboratory of Advanced Technology for materials Synthesis and Processing Biomedical Material and Engineering Center of Hubei ProvinceWuhan University of TechnologyWuhan 430070China

A novel strategy was developed to prepare the methacrylic gelatin-dopamine(GelMA-DA)/Ag nanoparticles(NPs)/graphene oxide(GO) composite hydrogels with good biocompatibility,mechanical properties,and antibacterial ***-inspired DA was utilized to modify the GelMA molecules,which imparts good adhesive performance to the ***,interfacial enhancer,not only improves mechanical properties of the hydrogels,but also provides anchor sites for loading Ag NPs through numerous oxygencontaining functional groups on the *** experimental results show that the GelMA/Ag NPs/GO hydrogels have good biocompatibility,and exhibit a swelling rate of 202±16%,the lap shear strength of 147±17 kPa,and compressive modulus of 136±53 kPa,in the case of the Ag NPs/GO content of 2 mg/*** activity of the hydrogels against both gram-negative and gram-positive bacteria is dependent on the Ag NPs/GO content derived from the release of Ag^(+).Furthermore,the GelMA/Ag NPs/GO hydrogels possess good adhesive ability,which is resistant to highly twisted state when stuck on the surface of *** results demonstrate promising potential of the GelMA-DA/Ag NPs/GO hydrogels as wound dressings for biomedical applications in clinical and emergent treatment.

关键词： GelMA dopamine,graphene oxide adhesion antibacterial ability

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Distinct Electrical and Mechanical Responses of a Cu-10Fe Composite Prepared by Hot-Pressed Sintering and Post Treatment

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 255-265页

作者： X.Y.Yue S.Y.Peng X.Zhang C.N.He Y.Z.Tian Key Laboratory for Anisotropy and Texture of materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang110819China School of materials Science and engineering and Tianjin Key Laboratory of Composite and Functional materials Tianjin UniversityTianjin300350China Research centre for Metallic Wires Northeastern UniversityShenyang110819China

A Cu-10wt%Fe composite was prepared through hot-pressed sintering,and the material was subsequently solution *** hot-pressed sintered and solution treated materials were rolled and *** precipitation behavior and performance changes were systematically studied by using scanning electron microscopy and transmission electron *** contrast to the hot-pressed sintered specimen,the solution treatment significantly affects the thermal stability and properties of the Cu-10wt%Fe *** Cu-10wt%Fe composite was prepared after solid solution,cold rolling and aging at 773 K for 1 h,and it obtained excellent tensile strength of 494 MPa,uniform elongation of 16.3%,electrical conductivity of 51.1%IACS and softening temperature of 838 *** for the distinct difference in thermal stability and properties between hot-pressed sintered and solution treated specimens were *** findings provide a theoretical basis for designing high-performance Cu-based in-situ composites by post treatment.

关键词： Cu-Fe composite Hot-pressed sintering Thermal stability Strength Electrical conductivity

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Vacancy healing for stable perovskite solar cells via bifunctional potassium tartrate

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Journal of Energy Chemistry 2024年第1期88卷 64-70,I0002页

作者： Jing Dou Yue Ma Xiuxiu Niu Wentao Zhou Xueyuan Wei Jie Dou Zhenhua Cui Qizhen Song Tinglu Song Huanping Zhou Cheng Zhu Yang Bai Qi Chen Experimental centre for Advanced materials School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory for Theory and Technology of Advanced Battery materials Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationBIC-ESATSchool of Materials Science and EngineeringPeking UniversityBeijing 100871China

Perovskite solar cell has gained widespread attention as a promising technology for renewable ***, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein, we demonstrate a bifunctional passivator of the potassium tartrate(PT) to address both challenges. PT minimizes the Pb leakage in perovskites and also heals cationic vacancy defects, resulting in improved device performance and stability. Benefiting from PT modification, the power conversion efficiency(PCE) is improved to 23.26% and the Pb leakage in unencapsulated films is significantly reduced to 9.79 ppm. Furthermore, the corresponding device exhibits no significant decay in PCE after tracking at the maximum power point(MPP) for 2000 h under illumination(LED source, 100 mW cm^(-2)).

关键词： Perovskite Potassium tartrate Lead leakage Long-term stability

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High-areal-capacity/power lithium metal microbattery configuration based on the mechanically flexible,ultra-lightweight,nanocellulose framework

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Nano Research 2024年第9期17卷 8155-8162页

作者： Shaowen Li Ting Zhao Helin Wang Zhiqiao Wang Min Zhang Ahu Shao Jiacheng Liu Zhaohui Wang Yue Ma State Key Laboratory of Solidification Processing Centre for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'an 710072China College of materials Science and engineering Hunan UniversityChangsha 410082China The Faculty of Printing Packaging Engineering and Digital Media TechnologyXi'an University of TechnologyXi'an 710048China

The ubiquitous implementation of integrated microelectronics requires the on-chip power sources featured with the lightweight configuration design,high areal-capacity-loadings as well as facile reaction kinetics that beyond the current available microbattery ***,this study constructs a mechanically flexible,nanocellulose fiber(NCF)reinforced microbattery configuration,which consists of metal-organic frameworks(ZIF-8)modified NCF as the separator(MOF@NCF),the carbonized MOF@NCF as the metallic deposition substrate(c-MOF@NCF)as well as gradient-structured LiFePO4 particles infiltrated in the NCF matrix(LFP@NCF)as the *** film-stacked,integrated NCF-based microbattery prototype not only achieves the facile reaction kinetics with homogenized,dendrite-free Li metal deposition at high-capacity-loadings(2 mAh·cm^(-2)),but also eliminates the necessary use of metallic current collector to maximize the electroactive mass ratio,which therefore enables the high energy density of 6.8 mWh·cm^(-2)at the power output of 1.36 mW·cm^(-2)as well as the robust cyclability upon various geometric flexing *** study presents a quantum leap towards the facile reaction kinetics and multi-scale interfacial stability for the flexible microbattery construction that based on the sustainable utilization of bio-scaffolds.

关键词： nanocellulose microbattery mechanical flexible ultra-lightweight high-areal-capacity

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High-temperature elemental segregation induced structure degradation in high-entropy fluorite oxide

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Journal of Advanced Ceramics 2024年第3期13卷 310-322页

作者： Yixuan Hu Mariappan Anandkumar Yumeng Zhang Joydip Joardar Atul Suresh Deshpande Xiaodong Wang Kolan Madhav Reddy School of materials Science and engineering Shanghai Jiao Tong UniversityShanghai 200240China Department of materials Science and Metallurgical engineering Indian Institute of Technology HyderabadSangareddy 502285India International Advanced Research centre for Powder Metallurgy and New materials(ARCI) Hyderabad 500005India

Fluorite-structured oxides constitute an important category of oxides with a wide range of high-temperature *** the concept of high entropy,high-entropy fluorite oxides(HEFOs)have showcased intriguing high-temperature application ***,unlocking this potential necessitates an assessment of their long-term stability under high-temperature *** this study,we conducted a prolonged heat treatment at 1000℃on typical HEFO,specifically(CeHfZrGdLa)O_(x).After 100 h,high-intensity X-ray diffraction(XRD)revealed a transition from a single-phase fluorite to a multi-phase *** investigation by analytical electron microscoy(AEM)demonstrated that this degradation resulted from facilitated element diffusion and consequent escalating chemical fluctuation at high temperatures,leading to spontaneous segregation and separation of Ce and La elements,forming Ce-rich,La-poor,and La-rich ***,the La-rich phase spontaneously transformed from a fluorite structure(space group Fm3m)to a bixbyite structure(space group Ia3)at elevated temperatures,resulting in the appearance of superstructure reflection in XRD profiles and electron diffraction *** the intricate phase decomposition,the energy band gap showed minimal variation,suggesting potential property stability of(CeHfZrGdLa)O_(x)across a broad range of *** findings offer valuable insights into the future applications of HEFOs.

关键词： phase transition high-temperature stability elemental segregation high-entropy fluorite oxides(HEFOs)

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Design and preparation of a crosslinkable,oil-resistant,and bio-based elastomer from fumarate

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Science China Chemistry 2024年第2期67卷 622-631页

作者： Hui Yang Haijun Ji Xinxin Zhou Shihan Yang Liwei Li Chaoying Sun Weiwei Lei Runguo Wang Liqun Zhang Beijing State Key Laboratory of Organic-Inorganic Composites&Beijing Laboratory of biomedical materials Beijing University of Chemical TechnologyBeijing100029China Hubei Key Laboratory of Polymer materials Faculty of Materials Science and EngineeringHubei UniversityWuhan430062China

Poly(diethyl fumarate-co-methoxyethyl acrylate-co-vinyl chloroacetate)(PDEFMV),a novel bio-based elastomer with a saturated structure,was synthesized via redox emulsion *** glass-transition temperatures of PDEFMV,adjusted through the variation of the diethyl fumarate-to-methoxyethyl acrylate feeding ratio,ranged from-36.1 to-14.8 ℃.The number-average molecular weights of PDEFMV ranged from 384,000 to 46,000 g/*** designing the molecular structure,vinyl chloroacetate was used to provide active sites for subsequent vulcanization and *** active chlorine groups within the PDEFMV chain reacted with the crosslinking agent trithiocyanuric acid under high temperature and pressure to form a nonsulfur crosslinked three-dimensional network *** achieve the desired properties,carbon black(CB,N330) was incorporated to reinforce PDEFMV,leading to the formation of PDEFMV/CB composites.A comprehensive study was conducted on the high-temperature oil resistance of PDEFMV/CB *** immersion in IRM903 oil at temperatures of 150 and 200 ℃ for 72 h,the mass and volume changes in PDEFMV/CB were lower than those observed in commercially available acrylate rubber(AR)/CB,indicating that PDEFMV exhibited superior oil ***,the aging characteristics and mechanisms of oil resistance in the PDEFMV/CB and AR/CB composites were investigated at different temperatures(150,200,and 250 ℃).The results provide insights into the operational temperature ranges suitable for PDEFMV/CB and offer valuable guidance for potential industrial applications.

关键词： diethyl fumarate molecular design bio-based elastomer solvent-free synthetic route high-temperature oil resistance

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