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Bifunctional core–shell co-catalyst for boosting photocatalytic CO_(2) reduction to CH_(4)

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Nano Research 2024年第3期17卷 1259-1266页

作者： Fangxu Dai Mingming Zhang Jishu Han Zhenjiang Li Shouhua Feng Jun Xing Lei Wang Key Laboratory of Eco-chemical Engineering Ministry of EducationCollege of Chemistry and Molecular EngineeringQingdao University of Science and TechnologyQingdao 266042China College of materials Science and Engineering Qingdao University of Science and TechnologyQingdao 266042China College of Environment and Safety Engineering Qingdao University of Science and TechnologyShandong Engineering Research Center for Marine Environment Corrosion and Safety ProtectionQingdao 266042China

Solar-light-driven CO_(2) reduction CO to CH_(4) and C2H6 is a complex process involving multiple elementary reactions and energy barriers.Therefore,achieving high CH_(4) activity and selectivity remains a significant challenge.Here,we integrate bifunctional Cu2O and Cu-MOF(MOF=metal-organic framework)core–shell co-catalysts(Cu2O@Cu-MOF)with semiconductor TiO_(2).Experiments and theoretical calculations demonstrate that Cu2O(Cu+facilitates charge separation)and Cu-MOF(Cu2+improves the CO_(2) adsorption and activation)in the core–shell structure have a synergistic effect on photocatalytic CO_(2) reduction,reducing the formation barrier of the key intermediate*COOH and*CHO.The photocatalyst exhibits high CH_(4) yield(366.0μmol·g^(-1)·h^(-1)),efficient electron transfer(3283μmol·g^(-1)·h^(-1))and hydrocarbon selectivity(95.5%),which represents the highest activity of Cu-MOF-based catalysts in photocatalytic CO_(2) reduction reaction.This work provides a strategy for designing efficient photocatalysts from the perspective of precise regulation of components.

关键词： bifunctional co-catalyst core–shell photocatalytic CO_(2)reduction

Regulating solid electrolyte interphases on phosphorus/carbon anodes via localized high-concentration electrolytes for potassium-ion batteries

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Journal of energy Chemistry 2023年第3期78卷 589-605,I0016页

作者： Wei Xiao Peiyi Shi Zhengkui Li Chong Xie Jian Qin Huijuan Yang Jingjing Wang Wenbin Li Jiujun Zhang Xifei Li Key Laboratory of Advanced Batteries materials for Electric Vehicles of China Petroleum and Chemical Industry Federation Institute of Advanced Electrochemical Energy&School of Materials Science and EngineeringXi’an University of TechnologyXi’an 710048ShaanxiChina Engineering Research Center of Conducting materials and Composite Technology Ministry of EducationXi’an 710048ShaanxiChina school of materials Science and Engineering Fuzhou UniversityFuzhou 350108FujianChina Center for International Cooperation on Designer Low-carbon&Environmental materials(CDLCEM) Zhengzhou UniversityZhengzhou 450001HenanChina

The resourceful and inexpensive red phosphorus has emerged as a promising anode material of potassium-ion batteries(PIBs) for its large theoretical capacities and low redox potentials in the multielectron alloying/dealloying reactions,yet chronically suffering from the huge volume expansion/shrinkage with a sluggish reaction kinetics and an unsatisfactory interfacial stability against volatile electrolytes.Herein,we systematically developed a series of localized high-concentration electrolytes(LHCE) through diluting high-concentration ether electrolytes with a non-solvating fluorinated ether to regulate the formation/evolution of solid electrolyte interphases(SEI) on phosphorus/carbon(P/C) anodes for PIBs.Benefitting from the improved mechanical strength and structural stability of a robust/uniform SEI thin layer derived from a composition-optimized LHCE featured with a unique solvation structure and a superior K+migration capability,the P/C anode with noticeable pseudocapacitive behaviors could achieve a large reversible capacity of 760 mA h g^(-1)at 100 mA g^(-1),a remarkable capacity retention rate of 92.6% over 200 cycles at 800 mA g^(-1),and an exceptional rate capability of 334 mA h g^(-1)at8000 mA g^(-1).Critically,a suppressed reduction of ether solvents with a preferential decomposition of potassium salts in anion-derived interfacial reactions on P/C anode for LHCE could enable a rational construction of an outer organic-rich and inner inorganic-dominant SEI thin film with remarkable mechanical strength/flexibility to buffer huge volume variations and abundant K+diffusion channels to accelerate reaction kinetics.Additionally,the highly reversible/durable full PIBs coupling P/C anodes with annealed organic cathodes further verified an excellent practical applicability of LHCE.This encouraging work on electrolytes regulating SEI formation/evolution would advance the development of P/C anodes for high-performance PIBs.

关键词： Potassium-ion batteries Phosphorus/carbon anodes Localized high-concentration electrolytes Solid electrolyte interphases Interfacial stability

First Principle Study of Cesium-based Lead-free Halide Double Perovskites

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Journal of Wuhan University of Technology(materials Science) 2023年第3期38卷 520-529页

作者：郑伟甘小燕 DU Dingjin WANG Yajie DAI Siqi GUO Liling LIU Hanxing school of materials Science and Engineering Wuhan University of TechnologyWuhan 430070China International school of materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Inorganic halide double perovskites A_(2)B'B"X_(6) have gained significant interests for their diverse composition,stable physicochemical properties,and potential for photoelectric applications.The influences of trivalent and monovalent cations on the formation energy,decomposition energy,electronic structure and optical properties of cesium-based lead-free Cs^(+)_(2)B'B"Br_(6) (B'=Na^(+),In^(+)Cu^(+),or Ag^(+);B"=Bi^(3),Sb^(3+),In^(3+)) are systematically studied.In view of the analysis and results of the selected double perovskites,for the double perovskites with different B-site trivalent cation,the band gap increases in the order of Cs_(2)AgInBr_(6),Cs_(2)AgSbBr_(6) and Cs_(2)AgBiBr_(6),with Cs_(2)AgBiBr_(6) possessing the highest thermodynamic stability.Therefore,the Bi-based perovskites are further studied to elucidate the effect of monovalent cation on their stability and electronics.Results show that the thermodynamic stability rises in the sequence of Cs_(2)NaBiBr_(6),Cs_(2)InBiBr_(6),Cs_(2)AgBiBr_(6) and Cs_(2)CuBiBr_(6).Notably,Cs_(2)CuBiBr_(6) exhibits a relatively narrow and appropriate band gap of 1.4634 eV,together with the highest absorption coefficient than other compounds,suggesting that Cs_(2)CuBiBr_(6) is a promising light absorbing material that can be further explored experimentally and be applied to optoelectronic devices.Our research offers theoretical backing for the potential optoelectronic application of cesium-based lead-free halide double perovskites in solar energy conversion.

关键词： lead-free double perovskites density functional theory Cs_(2)B'B"Br_(6) stability electronic properties optical property stability

Mixed Grain Structure and Mechanical Property of Ti-6Al-4V-0.5BN(wt%)Alloy Fabricated by Selective Laser Melting

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Acta Metallurgica Sinica(English Letters) 2023年第6期36卷 917-925页

作者： Liqing Wang Zhen Zhang Zhanyong Zhao Shenghua Zhang Peikang Bai school of materials Science and Engineering North University of ChinaTaiyuan 030051China school of materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan 030024China

A novel Ti-6Al-4V-0.5BN(wt%)alloy fabricated by selective laser melting exhibited mixed grain structure containing band distributed columnar and equiaxed prior-β-Ti grains.The mixed grain structure,microstructure within prior-β-Ti grains and compressive properties have been characterized and discussed.The band thickness ratio of columnar to equiaxed prior-β-Ti grains was 3:1.The columnar grains were 10±4μm in width and 53±24μm in length,the equiaxed grains were 7±4μm in size.There were nano-to micron-scaledα-Ti/β-Ti laths within prior-β-Ti grains and nano-scaled TiB along prior-β-Ti grain boundaries.The heterogeneous distribution of prior-β-Ti grain boundaries and TiB particles contributed to the hardness difference between the bands of columnar and equiaxed prior-β-Ti grains.BN addition resulted in the mixed grain structure in the SLMed Ti64 alloy,forming a multi-scaled microstructure,which contributed to high compressive yield strength of 1648 MPa.This work provided a new strategy to regulate the microstructure for the additive manufactured Ti alloys.

关键词： Selective laser melting Ti-6Al-4V alloys Prior-β-Ti grains Strength

Disaster Awareness and Preparedness Among Older Adults in Canada Regarding Floods, Wildfires, and Earthquakes

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International Journal of Disaster Risk Science 2024年第2期15卷 198-212页

作者： Evalyna Bogdan Rachel Krueger Julie Wright Kyle Woods Shaieree Cottar school of Administrative Studies Disaster and Emergency Management Program York University Partners for Action Faculty of Environment University of Waterloo Department of Geography and Environmental Management University of Waterloo

Older adults are significantly impacted by natural hazards and disasters that are exacerbated by climate change. Understanding their awareness and preparedness is essential for enhancing disaster resilience. This study investigated the attitudes, actions, and recommendations of older adults regarding natural hazards that pose risks in their geographic area—specifically floods, wildfires, and/or earthquakes in Canada. Methods for this study included survey and focus groups with older adults(n = 161 and n = 10, respectively) and other high-risk groups from across Canada, that are vulnerable to these natural hazards. The main findings from this study are that current awareness and preparedness among older adults is low, though stronger perceptions of risks are associated with risks specific to geographic locations where respondents live. Several barriers, such as hazard vulnerability misperceptions, cost-related reasons, and lack of hazard awareness have resulted in low awareness and preparedness among these populations. The two main recommendations arising from this research are:(1) improve awareness and preparedness with tailor-made emergency preparedness materials for older adults; and(2) adopt community-based approaches to disaster preparedness through existing community groups to strengthen social connections with a focus on locally specific hazards. The findings from this research can be applied to other hazards, including heatwaves and pandemics.

关键词： Canada Community-based disaster risk management Disaster awareness and preparedness Disaster resilience Natural hazards Older adults

Track-before-detect for bistatic radar based on pseudo-spectrum

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Chinese Journal of Aeronautics 2024年第1期37卷 236-246页

作者： Tao HAN Gongjian ZHOU school of Electronics and Information Engineering Harbin Institute of TechnologyHarbin 150001China Key Laboratory of Marine Environmental Monitoring and Information Processing Ministry of Industry and Information TechnologyHarbin 150001China

Track-Before-Detect(TBD) is an efficient method to detect dim targets for radars. Conventional TBD usually follows an approximate motion model of the target, which may cause an inaccurate integration of the target energy. A TBD technique on basis of pseudo-spectrum in mixed coordinates adopting an accurate motion model for bistatic radar system is developed in this paper.The predicted position in bistatic polar plane is derived according to a nonlinear function that exactly describes the constant Cartesian velocity motion. Then around the predicted position, a pseudo-spectrum is formulated and its samples are accumulated to the integration frame for energy integration. The evolution of the state and the procedure of accumulation of the target energy are derived elaborately. The superior performance of the proposed method is demonstrated by some simulations.

关键词： Weak target detection Bistatic radar Track-before-detect Pseudo-spectrum Multiframe integration

Parametric instability in the pure-quartic nonlinear Schrödinger equation

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Chinese Physics B 2024年第3期33卷 316-321页

作者：张云红刘冲 school of Physics Northwest UniversityXi'an 710127China Shaanxi Key Laboratory for Theoretical Physics Frontiers Xi'an 710127China Peng Huanwu Center for Fundamental Theory Xi'an 710127China

We study the nonlinear stage of modulation instability(MI)in the non-intergrable pure-quartic nonlinear Schrödinger equation where the fourth-order dispersion is modulated periodically.Using the three-mode truncation,we reveal the complex recurrence of parametric resonance(PR)breathers,where each recurrence is associated with two oscillation periods(PR period and internal oscillation period).The nonlinear stage of parametric instability admits the maximum energy exchange between the spectrum sidebands and central mode occurring outside the MI gain band.

关键词： modulation instability parametric resonance breather three-mode truncation energy exchange

Molecular dynamics study of hydrogen-induced cracking behavior of ferrite–pearlite gas transmission pipeline steel

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Journal of Iron and Steel Research(International) 2024年第2期31卷 488-500页

作者： Tao-long Xu Si-han Guo Gong-zhen He Hao-yu Han Petroleum Engineering school Southwest Petroleum UniversityChengdu610500SichuanChina Sichuan East Gas Transmission Sales Center of Sinopec Natural Gas Branch Wuhan430074HubeiChina

Hydrogen embrittlement of pipelines depends on the hydrogen-induced cracking behavior of the pipeline steel microstructure.Based on molecular dynamics analysis,the ferrite–cementite(α-Fe/Fe3C)lamellar atomic structure with the Bagaryatskii orientation relationship was established,and stepwise relaxation of the conjugate gradient energy minimization and constant-temperature and constant-pressure relaxation were performed under NPT(the isothermal–isobaric)conditions.The mechanical property curves of theα-Fe/Fe3C models were obtained under different cementite terminal plane structures,and the evolution of the atomic structure was analyzed in detail.In addition,the influence of different hydrogen concentrations,different temperatures,different strain rates,changes in voids,and different micro-degrees of freedom on the deformation and failure mechanism of the model was investigated,aiming to provide a reliable way to explore the micro-mechanism of macro-cracking behavior of pipeline steel.

关键词： Ferrite-cementite lamellar structure Pipeline steel Failure mechanism Crack propagation Molecular dynamics

Enhanced gas production and CO_(2) storage in hydrate-bearing sediments via pre-depressurization and rapid CO_(2) injection

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Chinese Journal of Chemical Engineering 2024年第3期67卷 126-134页

作者： Hongnan Chen Yifei Sun Bojian Cao Minglong Wang Ming Wang Jinrong Zhong Changyu Sun Guangjin Chen State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China school of Chemistry and Chemical Engineering Changsha University of Science&TechnologyChangsha 410114China

Carbon emission reduction and clean energy development are urgent demands for mankind in the coming decades.Exploring an efficient CO_(2) storage method can significantly reduce CO_(2) emissions in the short term.In this study,we attempted to construct sediment samples with different residual CH_(4) hydrate amounts and reservoir conditions,and then investigate the potentials of both CO_(2) storage and enhanced CH_(4) recovery in depleted gas hydrate deposits in the permafrost and ocean zones,respectively.The results demonstrate that CO_(2) hydrate formation rate can be significantly improved due to the presence of residual hydrate seeds;However,excessive residual hydrates in turn lead to the decrease in CO_(2) storage efficiency.Affected by the T-P conditions of the reservoir,the storage amount of liquid CO_(2) can reach 8 times that of gaseous CO_(2),and CO_(2) stored in hydrate form reaches 2-4 times.Additionally,we noticed two other advantages of this method.One is that CO_(2) injection can enhance CH_(4) recovery rate and increases CH_(4) recovery by 10%-20%.The second is that hydrate saturation in the reservoir can be restored to 20%-40%,which means that the solid volume of the reservoir avoids serious shrinkage.Obviously,this is crucial for protecting the goaf stability.In summary,this approach is greatly promising for high-efficient CO_(2) storage and safe exploitation of gas hydrate.

关键词： Hydrate Depressurization CO_(2) storage CH_(4) production Reservoir remediation