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Lanthanum-based nanomaterials for oxygen evolution reaction

Journal of rare Earths 2025年第6期43卷 1091-1099页

作者： Miao He Ping Wang Jiasai Yao Yifei Li Senyao Meng Zhenxing Li State Key Laboratory of Heavy Oil Processing College of New Energy and MaterialsChina University of Petroleum (Beijing)

rare earth has a unique electronic structure and brings highly anticipated properties in light,electricity,heat and *** is widely distributed among the rare earth elements and has a great potential for the electrocatalytic *** paper reviews the common types and synthesis methods of lanthanum-based catalysts used in the electrocatalytic oxygen evolution reaction,and highlights the optimization of lanthanum-based *** electronic structure and active sites of the catalysts can be adjusted through atomic doping,interfacial modulation,and structural defects to enhance the ***,the development of lanthanum-based catalyst is envisioned.

关键词： Electrocatalysis Lanthanum Oxygen evolution reaction rare earths Synthesis method

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developing a method for calculating the mean outdoor radiant temperature for thermal stress in Guangzhou

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Building Simulation 2024年第11期17卷 1989-2006页

作者： Xiaoqing Zhou Tianwei Tang Xiwen Feng Naiping Gao Yanping Yang Zhaosong Fang School of Civil Engineering and Transportation Guangzhou UniversityGuangzhou510006China School of Mechanical Engineering Tongji UniversityShanghai200092China

Cities around the world are exposed to increasing heat stress as a result of the heat island effect exacerbated by extreme weather events,population growth and increased *** promote outdoor activities and protect human health,there is an urgent need for a tool to assess the outdoor thermal *** the air temperature(Ta)and relative humidity(rH)are usually available from weather stations,but the mean radiant temperature(MrT)*** MrT is a key variable in determining outdoor thermal ***,it is necessary to develop a simple and accurate method for calculating MrT,in order to compute the corresponding thermal indices,which can be used to assess the thermal environment more *** study was conducted at a university in Guangzhou,*** different ground-cover surfaces(concrete,asphalt,lawn,and granite)were selected for *** T_(a),black-globe temperature(T_(g)),long-wave(L),and short-wave(K)radiation in six directions,and wind speeds(V_(a))were measured under unshaded *** MrT obtained by the six-direction integral method was used as the base value and regression analyses were performed with Ta,K↓(downward short-wave),and *** addition,the six indices—significance(P),linear regression coefficient(r^(2)),consistency index(d),root mean square error(rMSE),mean bias error(MBE),and mean absolute error(MAE)—were used for quantitative analysis to explore the feasibility of this *** study compared five calculation models on MrT:MrTSdIM(six-direction integral method),MrTBGTM-Va-0.1Hz(black-globe thermometer method,0.1 Hz wind speed measurement frequency),MrTBGTM-Va-10Hz(black-globe thermometer method,10 Hz wind speed measurement frequency),MrTBGTM-P(polynomial regression based on black-globe thermometer method),and MrTSdIM-P(polynomial regression based on six-direction integral method).The MrTSdIM was used as a baseline value,and the values obtained by other four methods were discussed and validated separ

关键词： mean radiant temperature outdoor thermal environment solar radiation ground-cover surface six-direction integral method

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Simultaneous enhancement of red luminescence and thermal stability of a novel red phosphor:A Li^(+)-Eu^(3+)co-occupied site strategy in BaAl_(2)Ge_(2)O_(8)lattices

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Journal of rare Earths 2024年第10期42卷 1846-1854页

作者： Wei Zhang Changjian Wang Xusheng Qiao Xianping Fan State Key Laboratory of Silicon Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou310027China Ocean Academy Zhejiang UniversityZhoushan316021China

The rapid development of phosphor-converted white light emitting diodes(pc-WLEds)requires new red phosphors with efficient and thermally stable luminescence for high-quality warm-white ***,it is still a challenge to discover red phosphors with facile synthesis,high internal quantum efficiency(IQE),excellent thermal stability and high color ***,a novel red-emitting Eu^(3+)activated barium dialuminum digermanate(BaAl_(2)Ge_(3)O_(8),EAGO)phosphor showing strong red emission at 610 nm was *** IQE is improved from 32.91%to 78.84%by employing a charge compensation *** lithium-ion co-dop ed BAGO:Eu^(3+)phosphor exhibits a nearly twofold increase in integral photoluminescence(PL)intensity and the high color purity reaches 94.17%.Impressively,the PL intensity of the BAGO:Eu^(3+),Li^(+)phosphor drops by only 2.6%at 150℃of that at room ***,the pc-WLEd using the red BAGO:Eu^(3+),Li^(+)phosphor exhibits white light with the chromaticity coordinate of(0.3515,0.3495),a high color-rendering index of 92 and a low correlated color temperature of 4746 *** these results manifest that BAGO:Eu^(3+),Li^(+)phosphor is a suitable red phosphor for nearultraviolet(NUV)chip-based pc-WLEds.

关键词： BaAl_(2)Ge_(2)O_(8):Eu^(3+) red phosphor Charge compensation High quantum efficiency Excellent thermal stability rare earths

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Significant effect of ordered micro-domain on cell boundary phase distribution and demagnetization curve squareness of Sm_(2)Co_(17)-type magnet

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rare Metals 2024年第4期43卷 1724-1735页

作者： Zhuang Liu Hai-Chen Wu Chao-Yue Zhang Chao-Qun Zhu Guo-Xin Chen Huan-Ming Lu ren-Jie Chen Aru Yan CISRI&NIMTE Joint Innovation Center for Rare Earth Permanent Magnets Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China University of Chinese Academy of Sciences Beijing100049China Analytical Center Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo315201China

Cu-rich cell boundary phase is difficult to precipitate evenly,resulting in a generally poor demagnetization curve squareness for Fe-rich Sm_(2)Co_(17)-type magnet,which is a key factor limiting the further improvement of magnetic energy *** this study,we report that nanoscale strip-like ordered micro-domains distributed in1:7H disordered matrix phase of the solid solution precursor is a new factor significantly affecting the precipitation and distribution of the cell boundary *** strip-like and continuous micro-twin structure with twin boundaries neatly perpendicular to the C-axis is observed after sintering *** solution treatment,sequential and long strip-like micro-twins gradually transform into disordered state along the basal plane,forming narrow disordered 1:7H(TbCu_(7)-type structure)phase between the separated strip-like ordered *** disordering transformation takes place via broken down of the long strip-like ordered micro-domains,which is accomplished by narrowing along the width direction followed by reduction of the ***,a new model revealing the effect of the ordered micro-domains on the formation of the cell boundary phase is *** boundaries enriched in Cu have already existed in the precursor with long strip-like ordered ***,the Cu-rich cell boundary phase acting as strong pinning centers cannot be precipitated homogeneously and distributed continuously after aging,resulting in a poor demagnetization curve squareness of Sm_(2)Co_(17)-type *** results indicate that significant broken down of the nanoscale ordered micro-domains in solution precursor is the key factor improving the distribution of cell boundary phase in Sm_(2)Co_(17)-type magnets.

关键词： Sm_(2)Co_(17) magnets Solution precursor Ordered micro-domains disordering transformation Cellular structure

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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

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A STOCHASTIC AUGMENTEd LAGrANGIAN METHOd FOr STOCHASTIC CONVEX programMING

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Journal of Computational Mathematics 2025年第2期43卷 315-344页

作者： Jiani Wang Liwei Zhang Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China School of Mathematical Sciences Dalian University of TechnologyDalian 116024China

In this paper,we analyze the convergence properties of a stochastic augmented Lagrangian method for solving stochastic convex programming problems with inequality *** models for stochastic convex programming problems are constructed from stochastic observations of real objective and constraint *** on relations between solutions of the primal problem and solutions of the dual problem,it is proved that the convergence of the algorithm from the perspective of the dual *** assumptions on how these random models are generated,when estimates are merely sufficiently accurate to the real objective and constraint functions with high enough,but fixed,probability,the method converges globally to the optimal solution almost *** addition,sufficiently accurate random models are given under different noise *** also report numerical results that show the good performance of the algorithm for different convex programming problems with several random models.

关键词： Stochastic convex optimization Stochastic approximation Augmented Lagrangian method duality theory

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Polyphenol-based antibacterial and antioxidative nanoparticles for improved peritonitis therapy

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Collagen and Leather 2024年第3期6卷 80-92页

作者： Jinhong dong Tianyou Wang Haotian Li Jianhua Zhang Hengjie Zhang Weijie Liu Xinru You Zhipeng Gu Yiwen Li Xianchun Chen Qiang Fu College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China Center for Nanomedicine and Department of Anesthesiology Brigham and Women's HospitalHarvard Medical SchoolBostonMA 02215USA

The development of advanced sustainable biomedical materials with superior biosafety and bioactivity for clinical applications is highly desirable. In the present investigation, biomass-based nanoparticles(NPs) were assembled through the Mannich reaction between the plant polyphenols and the broad-spectrum antibiotic tigecycline(TG). The fabricated NPs with uniform size demonstrated excellent oxidative balance effects, pH-responsive release properties and antibacterial performances. Furthermore, the intracellular and in vivo studies confirmed that the NPs are capable of reducing oxidative damage to cells and significantly repairing tissue injury in mice with peritonitis. This work presents an effective method and idea for constructing biomass-based materials for the treatment of infection-induced diseases.

关键词： Biomass materials Natural polyphenols Antibiotics Antioxidative Peritonitis

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Achieving full mutualism with massive passive devices for multiuser MIMO symbiotic radio

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Science China(Information Sciences) 2024年第9期67卷 196-212页

作者： Jingran XU Zhuoyin dAI Yong ZENG Shi JIN Tao JIANG National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories Research Center of 6G Mobile Communications School of Cyber Science and Engineering and Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology

Symbiotic radio(Sr) is one of the attractive communication technologies to facilitate largescale Internet of Things(IoT) connections with enhanced energy and spectrum efficiency, where passive backscatter devices(Bds) modulate their information over the radio frequency(rF) signals emitted by the active primary transmitters(PTs). Meanwhile, the primary transmission can be strengthened with the additional multipaths created by Bds. To capitalize to a greater extent on the mutualism relationship between the two types of communication, this paper studies multiple-input multiple-output(MIMO) Sr communication systems including multiple PTs and massive Bds. We derive the achievable rate expressions of each PT and Bd, as well as the sum rate expressions of primary and secondary communication, *** asymptotic analysis is given to derive the active and passive communication rates with a large number of Bds. Furthermore, for the general case with a finite number of Bds, we study the precoding optimization problem to maximize the sum rate of primary communication, while ensuring that the sum rate of secondary communication and the individual rate for each PT and Bd in the prescribed active and passive user sets satisfy the specified thresholds. Simulation results are presented to verify the analytical studies.

关键词： multiuser MIMO Sr backscattering massive backscatter devices asymptotic analysis active and passive communication

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In-situ construction of carbon fiber gradient periodic structure in Al_(2)O_(3)f/SiOC composites for ultra-broadband and high-temperature electromagnetic wave absorption

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Journal of Materials Science & Technology 2024年第27期194卷 87-97页

作者： Fan Yang Jimei Xue Cunxian Wang Jiuzheng Zhao Shangwu Fan Xiaomeng Fan Laifei Cheng Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China School of Aeronautics Institute of Extreme MechanicsNorthwestern Polytechnical UniversityXi’an 710072China

Ceramic matrix composites(CMC)are widely utilized in high-temperature components of aero-engines for load-bearing and electromagnetic stealth synergy due to their superior toughening and designable electromagnetic ***,the design of ultra-broadband electromagnetic wave(EMW)absorp-tion at thin thicknesses(d<10 mm)has been difficult and focused,especially the design of *** by 3d printing technology and the structural characteristic of 2d CMC,this study inge-niously devised and proposed a novel carbon fiber gradient periodic structure in Al_(2)O_(3f)/SiOC composites to enhance the ultra-broadband EMW absorption properties at a wide temperature *** optimizing the geometric structure parameters,the Al_(2)O_(3f)/SiOC composites with the carbon fiber gradient periodic structure have exhibited exceptional ultra-broadband EMW absorption properties at elevated tempera-tures and excellent mechanical *** composites have attained a minimum reflection loss(rLmin)of-30 dB and a high absorption efficiency of more than 84%,ranging from 9.3 to 40 GHz at a thickness of 9 *** to the temperature insensitivity of discrete periodic structures,the composites can adapt to high temperatures up to 700℃.Additionally,compared to the Al_(2)O_(3f)/SiOC composites,the flexural strength and fracture toughness of the Al_(2)O_(3f)/SiOC composites with carbon fiber gradient peri-odic structure have significantly increased to 398 MPa and 15.6 MPa m1/2,*** work breaks through the limitation of the design and fabrication of 3d periodic structures in CMC,creating a novel oxide-CMC with ultra-broadband EMW absorption properties at a wide temperature range and enhanced mechanical properties.

关键词： Carbon fiber Gradient periodic structure Ceramic matrix composites Ultra-broadband absorption High-temperature

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Comprehensive investigation on the structural,electronic and mechanical properties of T-Mg_(32)(Al,Zn)_(49)phases in Al-Mg-Zn alloys

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Journal of Materials Science & Technology 2024年第6期173卷 237-246页

作者： Boyu Xue Wei Xiao Xiwu Li Guanjun Gao Xiaowu Li Yongan Zhang Ligen Wang Baiqing Xiong State Key Laboratory of Nonferrous Metals and Processes China GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering Institute Co. Ltd.Beijing 101407China General Research Institute for Nonferrous Metals Beijing 100088China Department of Materials Physics and Chemistry School of Materials Science and EngineeringKey Laboratory for Anisotropy and Texture of MaterialsMinistry of EducationNortheastern UniversityShenyang 110819China

In the development process of crossover aluminum alloys,T-Mg_(32)(Al,Zn)_(49)phases play a significant role in the precipitation strengthening ***,comprehensive understandings of the structural characteristics,interactions among alloying elements,mechanical property dependence on composition variation,effects of doping and defects *** still inadequate.A combination of density functional theory(dFT)calculations and special quasi-random structures(SQSs)was applied to investigate the formation energies,lattice parameters,electronic structures and mechanical properties of the disordered T-phases,as well as the effects of possible defects and alloying *** formation energy and lattice constant of the T-phase gradually vary from 0 to-0.12 eV/atom and from 1.460 to 1.405 nm,respectively,with increasing Zn ***-3d orbitals exhibit stronger hybridization with Al-3s than Mg-3s orbitals,and this is further enhanced by increasing Zn contents,leading to improved covalency and mechanical properties of the *** T-phases show good ductility according to the Poisson's ratio ν,Cauchy's pressure and G/*** A site is more favorable to remain vacant in Al-rich and Zn-poor environments,which is consistent with the previous experimental *** alloying elements,Zn atoms tends to occupy Al atoms at the B,C and F sites and Mg atoms at the G *** Cu and Ag elements can decrease the formation energy of T-phases and possibly produce a greater number of T-phases during the precipitation *** effect of Ag is more significant relative to Cu due to the deeper orbital *** computational results show good agreement with previous experimental data and provide new insights into the compositional design of new Al-Mg-Zn alloys.

关键词： Al-Mg-Zn alloys Precipitation Mechanical properties Thermodynamic stability density functional theory

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