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Brightening heavily doped upconversion nanoparticles by tuning characteristics of core-shell structures

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Journal of Rare Earths 2024年第5期42卷 947-954,I0005页

作者： Yangyang Niu Zhihao Bao Yuqin Gao Mengchao Guo Jingyao Liu Jinjun Shao Min Lu Ze yuan Xiaoji xie School of Flexible Electronics(Future Technologies)&Institute of Advanced Materials(IAM) Nanjing Tech UniversityNanjing211816China

Heavily doped upconversion nanoparticles(UCNPs)potentially have exceptional photon upconversion abilities that are promising for diverse applications,such as lasing and super-resolution ***,heavily doped UCNPs typically can only offer mediocre upconversion luminescence intensity,and there still lacks general guidelines for the design and synthesis of heavily doped ***,in order to boost the upconversion luminescence of heavily doped UCNPs,we studied the influence of characteristics of the core-shell structure on heavily doped UCNPs'upconversion *** find that some empirical guidelines derived from conventional UCNPs are not suitable for heavily doped *** NaYbF_(4):Tm@NaYF_(4) core-shell UCNPs with a high concentration of Yb_(3+)as a representative,our studies reveal that a rather thick inert NaYF4 shell is needed to protect the UCNPs from surface quenching,and the upconversion luminescence may undergo the cooperative sensitization process,which should be due to the highly concentrated Yb~(3+)*** addition,the upconversion luminescence of heavily doped NaYbF4:Tm UCNPs exhibits no obvious dependence on the type of inert ***,our results show that confining both Yb~(3+)and Tm~(3+)dopants in a thin layer(known as theδ-doping strategy)does not work well in the heavily doped ***,we propose a NaYbF_(4):Tm@NaYbF_(4)@NaYF_(4) core-shell-shell structure to enhance the luminescence of heavily doped UCNPs,by weakening the dissipation of excitation energy and strengthening the *** findings should be helpful to establish general design principles for developing the brightest possible UCNPs that can meet the requirements of various applications.

关键词： Luminescence Upconversion Nanomaterials Rare earths Lanthanide doping

Absence of metallicity and bias-dependent resistivity in low-carrier-density EuCd_(2)As_(2)

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Science China(Physics,Mechanics & Astronomy) 2024年第4期67卷 119-125页

作者： Yuxiang Wang Jianwen Ma Jian yuan Wenbin Wu Yong Zhang Yicheng Mou Jiaming Gu Peihong Cheng Wu Shi xiang yuan Jinglei Zhang Yanfeng Guo Cheng Zhang State Key Laboratory of Surface Physics and Institute for Nanoelectronic Devices and Quantum Computing Fudan UniversityShanghai 200433China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200241China Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field Laboratory of the Chinese Academy of SciencesHefei 230031China School of Physics and Electronic Science East China Normal UniversityShanghai 200241China Zhangjiang Fudan International Innovation Center Fudan UniversityShanghai 201210China ShanghaiTech Laboratory for Topological Physics Shanghai 201210China

EuCd_(2)As_(2)was theoretically predicted to be a minimal model of Weyl semimetals with a single pair of Weyl points in the ferromagnet ***,the heavily p-doped Eu Cd_(2)As_(2)crystals in previous experiments prevent direct identification of the semimetal ***,we present a comprehensive magneto-transport study of high-quality Eu Cd_(2)As_(2)crystals with ultralow bulk carrier density(10^(13)cm^(-3)).In contrast to the general expectation of a Weyl semimetal phase,Eu Cd_(2)As_(2)shows insulating behavior in both antiferromagnetic and ferromagnetic states as well as surface-dominated conduction from band ***,the application of a dc bias current can dramatically modulate the resistance by over one order of magnitude,and induce a periodic resistance oscillation due to the geometric *** nonlinear transport results from the high nonequilibrium state induced by an electrical field near the band *** results suggest an insulating phase in Eu Cd_(2)As_(2)and put a strong constraint on the underlying mechanism of anomalous transport properties in this system.

关键词： magnetic Weyl semimetal quantum transport Hall effect nonlinear resistivity

Optimizing 3d spin polarization of CoOOH by in situ Mo doping for efficient oxygen evolution reaction

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Carbon Energy 2024年第1期6卷 236-244页

作者： Zhichao Jia Yang yuan Yanxing Zhang xiang Lyu Chenhong Liu Xiaoli Yang Zhengyu Bai Haijiang Wang Lin Yang Key Laboratory of Green Chemical Media and Reactions School of Chemistry and Chemical EngineeringCollaborative Innovation Center of Henan Province for Green Manufacturing of Fine ChemicalsMinistry of EducationHenan Normal UniversityXinxiangHenanChina School of Physics Henan Normal UniversityXinxiangHenanChina Oak Ridge National Laboratory Electrification and Energy Infrastructures DivisionOak RidgeTennesseeUSA Department of Mechanical and Energy Engineering Key Laboratory of Energy Conversion and Storage TechnologiesSouthern University of Science and TechnologyShenzhenGuangdongChina

Transition-metal oxyhydroxides are attractive catalysts for oxygen evolution reactions(OERs).Further studies for developing transition-metal oxyhydroxide catalysts and understanding their catalytic mechanisms will benefit their quick transition to the next ***,Mo-doped CoOOH was designed as a high-performance model electrocatalyst with durability for 20 h at 10 mAcm−***,it had an overpotential of 260 mV(glassy carbon)or 215 mV(nickel foam),which was 78 mV lower than that of IrO_(2)(338 mV).In situ,Raman spectroscopy revealed the transformation process of *** using the density functional theory showed that during OER,doped Mo increased the spin-up density of states and shrank the spin-down bandgap of the 3d orbits in the reconstructed CoOOH under the electrochemical activation process,which simultaneously optimized the adsorption and electron conduction of oxygen-related intermediates on Co sites and lowered the OER *** research provides new insights into the methodical planning of the creation of transition-metal oxyhydroxide OER catalysts.

关键词： electrocatalyst in situ Raman Mo-doped CoOOH oxygen evolution reaction

Regio-and Stereoselective Polymerization of Bio-based Ocimene by Rare-Earth Metal Catalysts

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Chinese Journal of Polymer Science 2024年第2期42卷 223-229,I0008页

作者： Qi-yuan Wang Li-Peng Sang Zhen Zhang Yang Jiang Hui Tian Xia Zhao xiang Guo Shi-Hui Li State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China Science and Technology on Aerospace Chemical Power Laboratory Hubei Institute of Aerospace ChemotechonologyXiangyang441003China Shanxi Coal Chemical Industry Technology Research Institute Xi’an710000China Hubei Institute of Aerospace Chemotechonology Xiangyang441003China

Coordination polymerization of renewable β-ocimene has been investigated using asymmetric diiminophosphinate lutetium complex1, β-diketiminate yttrium complex 2, bis(phosphino)carbazolide yttrium complex 3, half-sandwich benzyl fluorenyl scandium complex 4 and pyridyl-methylene-fluorenyl rare-metal complexes 5a–5c. Complexes 1, 4 and 5a–5c show trans-1,2-regioselectivities and high activities, of which 5c exhibits excellent isoselectivity(mmmm>99%). Conversely, complexes 2 and 3 promote β-ocimene polymerization to produce isotactic cis-1,4-polyocimenes(cis-1,4>99%, mm>95%). Diblock copolymers cis-1,4-PIP-block-cis-1,4-POc and cis-1,4-PBD-block-cis-1,4-POc are obtained in one-pot reactions of β-ocimene with isoprene and butadiene using complex 3. Epoxidation and hydroxylation of polyocimene afford functionalized polyolefins with enhanced T_(g)(from-20 ℃ to 79 ℃ and 74 ℃) and hydrophilicity.

关键词： Biobased monomer Terpenes Ocimene Rare-earths Polymerization Regio/stereoselectivity Elastomer

Barley Protein LFBEP-C1 from Lactiplantibacillus plantarum dy-1 Fermented Barley Extracts by Inhibiting Lipid Accumulation in a Caenorhabditis elegans Model

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Biomedical and Environmental Sciences 2024年第4期37卷 377-386页

作者： ZHANG Jia Yan LIU Meng Ting LIU Yu Hao DENG Huan BAI Juan xie Jian Hua XIAO xiang School of Food and Biological Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina State Key Laboratory of Food Science and Technology Nanchang UniversityNanchang 330047JiangxiChina

Objective This study aimed to investigate the lipid-lowering activity of LFBEP-C1 in high glucose-fed Caenorhabditis elegans(***).Methods In this study,the fermented barley protein LFBEP-C1 was prepared and tested for its potential anti-obesity effects on *** worms were fed Escherichia coli OP50(*** OP50),glucose,and different concentrations of *** size,lifespan,movement,triglyceride content,and gene expression were *** results were analyzed using ANOVA and Tukey's multiple comparison *** Compared with the model group,the head-swing frequency of *** in the group of LFBEP-C1 at 20μg/mL increased by 33.88%,and the body-bending frequency increased by 27.09%.This indicated that LFBEP-C1 improved the locomotive ability of *** average lifespan of *** reached 13.55 days,and the body length and width of the *** decreased after LFBEP-C1 ***,LFBEP-C1 reduced the content of lipid accumulation and triglyceride *** expression levels of sbp-1,daf-2,and mdt-15 significantly decreased,while those of daf-16,tph-1,mod-1,and ser-4 significantly increased after LFBEP-C1 *** in these genes explain the signaling pathways that regulate lipid *** LFBEP-C1 significantly reduced lipid deposition in *** fed a high-glucose diet and alleviated the adverse effects of a high-glucose diet on the development,lifespan,and exercise behavior of *** addition,LFBEP-C1 regulated lipid metabolism mainly by mediating the expression of genes in the sterol regulatory element-binding protein,insulin,and 5-hydroxytryptamine signaling pathways.

关键词： LFBEP-C1 Fermentation Protein Caenorhabditis elegans Lipid accumulation Signaling pathway

How mesenchymal stem cells transform into adipocytes:Overview of the current understanding of adipogenic differentiation

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World Journal of Stem Cells 2024年第3期16卷 245-256页

作者： Shan-Shan Liu xiang Fang Xin Wen Ji-Shan Liu Miribangvl Alip Tian Sun yuan-yuan Wang Hong-Wei Chen Department of Reumatology and Immunology Nanjing Drum Tower HospitalThe Affiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008Jiangsu ProvinceChina Department of Emergency Nanjing Drum Tower HospitalThe Affiliated Hospital of Medical SchoolNanjing UniversityNanjing 210008Jiangsu ProvinceChina Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education School of Biological Science and Medical EngineeringBeihang UniversityBeijing 100191China Anhui Key Laboratory of Infection and Immunity Bengbu Medical CollegeBengbu 233000Anhui ProvinceChina

Mesenchymal stem cells(MSCs)are stem/progenitor cells capable of self-renewal and differentiation into osteoblasts,chondrocytes and *** transformation of multipotent MSCs to adipocytes mainly involves two subsequent steps from MSCs to preadipocytes and further preadipocytes into adipocytes,in which the process MSCs are precisely controlled to commit to the adipogenic lineage and then mature into *** studies have shown that the master transcription factors C/enhancer-binding protein alpha and peroxisome proliferation activator receptor gamma play vital roles in ***,the mechanism underlying the adipogenic differentiation of MSCs is not fully ***,the current knowledge of adipogenic differentiation in MSCs is reviewed,focusing on signaling pathways,noncoding RNAs and epigenetic effects on DNA methylation and acetylation during MSC ***,the relationship between maladipogenic differentiation and diseases is briefly *** hope that this review can broaden and deepen our understanding of how MSCs turn into adipocytes.

关键词： Mesenchymal stem cell Adipogenic differentiation Signaling pathway Noncoding RNA Epigenetic regulation

The Active Compensation Technique for Large Reflector Antennas Based on Quadratic Curve Fitting

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Research in Astronomy and Astrophysics 2024年第7期24卷 226-234页

作者： Tian-xiang Zheng Bin-Bin xiang Han-Wei Cui Wei Wang Pei-yuan Lian Shang-Ming Lin Yang Zhang Jian-Ping Zhou Kai Li School of Mechanical Engineering Xinjiang UniversityUrumqi 830017China School of Mechano-Electronic Engineering Xidian UniversityXi’an 710017China Xi’an Institute of Optics and Precision Mechanics Chinese Academy of SciencesXi’an 710119China

Active reflectors are often used to compensate the surface distortion caused by environmental factors that degrade the electromagnetic performance of large high-frequency reflector *** is crucial for maintaining high gain operation in antennas.A distortion compensation method for the active reflector of a large dual-reflector antenna is proposed.A relationship is established between the surface deformation and the optical path difference for the primary reflector by geometric ***,employing finite element analysis,a polynomial fitting approach is used to describe the impact of adjusting points on the reflector surface based on the coordinates of each *** standardizing the positions of various panels on the reflector,the fitting ns can be applied to the reflector panels of similar ***,based on the distribution characteristics of the primary reflector panels,the adjustment equation for the actuators is derived by the influence matrix *** can be used to determine the adjustment amount of actuators to reduce the rms of the optical path ***,the least squares method is employed to resolve the matrix *** example of a 110 m aperture dual-reflector antenna is carried out by finite element analysis and the proposed *** results show that the optical path difference is reduced significantly at various elevation cases,which indicates that the proposed method is effective.

关键词： Methods analytical-Methods numerical-Telescopes

High temperature polyimide nanocomposites containing twodimensional nanofillers for improved thermal stability and capacitive energy storage performance

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Nano Research 2024年第8期17卷 7746-7755页

作者： Ding Ai Yuting Han Zongliang xie Xi Pang yuan Chang He Li Chenglong Wu Yonghong Cheng Guanglei Wu State Key Laboratory of Electrical Insulation and Power Equipment School of Electrical EngineeringXi’an Jiaotong UniversityXi’an 710049China Institute of Materials for Energy and Environment State Key Laboratory of Bio-Fibers and Eco-TextilesCollege of Materials Science and EngineeringQingdao UniversityQingdao 266071China

Future electronic devices toward high integration and miniaturization demand reliable operation of dielectric materials at high electric fields and elevated ***,the electrical deterioration caused by Joule heat generation remains a persistent challenge to ***,the solution-processed polyimide(PI)nanocomposites with unique two-dimensional(2D)alumina nanoplates are *** improvements in the breakdown strength,charge–discharge efficiency and discharged energy density at elevated temperatures have been demonstrated in the composites,owing to simultaneously suppressed conduction loss and increased thermal conductivity upon the incorporation of 2D Al_(2)O_(3) nanofillers possessing excellent dielectric insulation and thermophysical *** predominance of Al_(2)O_(3) nanoplates in enhancing thermal stability and high-temperature capacitive performance over nanoparticles and nanowires is validated experimentally and is further rationalized via finite element ***,the Al_(2)O_(3) nanoplates filled PI nanocomposite exhibits a hightemperature capability up to 200℃ and remarkable efficiency(e.g.≥95% at 200 MV/m)over a wide temperature range,which outperforms commercial dielectric polymers and rivals the state-of-the-art polyimide nanocomposites.

关键词： capacitors polymer nanocomposites high temperature energy storage thermal stability

Pathogen-induced methylglyoxal negatively regulates rice bacterial blight resistance by inhibiting OsCDR1 protease activity

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Molecular Plant 2024年第2期17卷 325-341页

作者： Zheng-Wei Fu Jian-Hui Li xiang Gao Shi-Jia Wang Ting-Ting yuan Ying-Tang Lu State Key Laboratory of Hybrid Rice College of Life SciencesRenmin Hospital of Wuhan UniversityWuhan UniversityWuhan 430072China Key Laboratory of Biology and Genetic Improvement of OilCrops Ministry of Agriculture and Rural AffairsOilCrops Research Institute of the Chinese Academy of Agricultural SciencesWuhan 430062China

Xanthomonas oryzae ***(Xoo)causes bacterial blight(BB),a globally devastating disease of rice(Oryza sativa)that is responsible for significant crop *** and sugar metabolites are important for pathogen infection,providing energy and regulating events associated with defense responses;howev-er,the mechanisms by which they regulate such events in BB are *** an inevitable sugar metabolite,methylglyoxal(MG)is involved in plant growth and responses to various abiotic stresses,but the underlying mechanisms remain *** and how MG functions in plant biotic stress responses is almost completely ***,we report that the Xoo strain PXO99 induces OsWRKY62.1 to repress transcrip-tion of OsGLY Il genes by directly binding to their promoters,resulting in overaccumulation of *** negatively regulates rice resistance against Pxo99:osglyll2 mutants with higher MG levels are more sus-ceptible to the pathogen,whereas OsGLYIl2-overexpressing plants with lower MG content show greater resistance than the wild *** of OsGLYll2 to prevent excessive MG accumulation confers broad-spectrum resistance against the biotrophic bacterial pathogens Xoo and Xanthomonas oryzae *** and the necrotrophic fungal pathogen Rhizoctonia solani,which causes rice sheath *** evidence shows that MG reduces rice resistance against PXO99 through CONSTITUTIVE DISEASE RESISTANCE 1(OsCDR1).MGmodifies the Arg97 residue of OsCDR1to inhibit its aspartic protease activ-ity,which is essential for OsCDR1-enhanced *** together,these findings illustrate how Xoo promotes infection by hijacking a sugar metabolite in the host plant.

关键词： Oryza sativa bacterial blight OsWRKY62.1 methylglyoxal OsCDR1