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Journal of Advanced Ceramics 2024年第2期13卷 247-254页

作者： Mingan Shi Shuyang Ma Wangsuo xia Ying Wang Jinzi yu Haitao Wu School of Materials Science and Physics China University of Mining and TechnologyXuzhou 221008China School of Environment and Material Engineering Yantai UniversityYantai 264005China

Novel Yb_(x)Ce_(1-x)O_(2-0.5x)(x=0-0.8)ceramics,designed by replacing Ce^(4+)with Yb^(3+)ions were prepared by conventional oxide reaction,and the structural stability of the cubic fluorite structure was assessed using lattice energy and ionic properties of Ce/Yb-O *** oxygen vacancy caused by unequal substitution,which played a decisive role in bond ionicity and lattice energy,was analyzed experimentally by XPS and also theoretically by first *** Yb_(x)Ce_(1-x)O_(2-0.5x) ceramics maintain a stable cubic fluorite structure when x≤0.47,corresponding to the minimum lattice energy of 4142 kJ/mol with the lowest ionicity as ƒ_(i)=87.57%.For microwave dielectric properties,when the Yb_(x)Ce_(1-x)O_(2-0.5x)(x=0-0.4)ceramics are pure phase,the porosity-corrected permittivity is dependent on the bond *** Q×ƒ values are related to the lattice energy and grain *** temperature coefficient of resonance frequency has been analyzed using bond *** the Yb_(x)Ce_(1-x)O_(2-0.5x)(x=0.5-0.8)ceramics are multiple phases,the microwave dielectric properties are associated with the phase composition and grain growth.

关键词： structure stability bond ionicity oxygen vacancy electronic localization function(ELF)

Mechanism of adjusting bypass ratio by front variable area bypass injector for a variable cycle engine

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Chinese Journal of Aeronautics 2024年第10期37卷 158-171页

作者： Qian LI Chen xia Guoping HUANG Omer MUSA Linjun LI Zonghan yu College of Energy and Power Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China AECC Sichuan Gas Turbine Establishment Chengdu 610500China College of Mechanical and Materials Engineering North China University of TechnologyBeijing 100144China

The Front Variable Area Bypass Injector(FVABI)is a key to bypass ratio adjustment for a Variable Cycle Engine(VCE).In order to study the role of the FVABI with the Core Driven Fan Stage(CDFS)duct,firstly,the engine bypass with the CDFS duct model and the equivalent engine bypass without the CDFS duct model are designed using the concept of a jet boundary *** comparing the difference between airflow driving forces in the two engine bypass models,the quantitative effects of the injection from the CDFS duct on the mass flow rate of the engine bypass airflow are obtained under different combinations of pressure difference and area ***,the CDFS duct injection characteristic map is obtained through the typical experiment of the *** on this map,the performance model of the FVABI is ***,the turbofan engine model with the Variable Inlet Guide Vane(VIGV),the First Variable Cycle Engine model(VCE1)with the CDFS duct and without the VIGV,and the Second Variable Cycle Engine model(VCE2)with the CDFS duct and VIGV are *** gain on the engine bypass ratio adjustment range caused by the injection from the CDFS duct is clarified by comparing the three engine *** is concluded that the bypass ratio adjustment range of the variable cycle engine with the FVABI is about twice that of the traditional turbofan engine.

关键词： Front variable area bypass injector Variable cycle engine Bypass ratio Injection CDFS duct injection characteristic map

How interfacial electron-donating defects influence the structure and charge of gold nanoparticles on TiO_(2)support

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Nano Research 2024年第7期17卷 5965-5974页

作者： Guang-Jie xia yu Fu Wei Cao Jun Li Yang-Gang Wang Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis Southern University of Science and TechnologyShenzhen 518055China School of Physical Sciences Great Bay UniversityDongguan 523000China Department of Chemistry Tsinghua UniversityBeijing 100084China

The reduction degree of TiO_(2)support is critical to the performances of metal *** many previous theoretical calculations,only the bridge oxygen vacancy(Ov)was considered as the electron-donating defect on reduced rutile TiO_(2)(r-TiO_(2−x))***,titanium adatoms(Tiad.),oxidized titanium islands(***),and acid hydroxyls(ObrH)also exist at the metal/support *** conducting density functional theory(DFT)calculations and ab initio molecular dynamics(AIMD)simulations,we compared r-TiO_(2−x)surfaces with Ov,Tiad.,***,and ObrH sites loaded with Au nanoparticles(NPs).The results showed the Au NPs were oxygen-phobic but titanium-philic,resulting in wetting of Ov and *** short contact with *** and *** Bader charges of Au NPs(QM)showed a good linear relationship with the ideal number of donating electrons(Ne)from the defective sites(QM=−KeNe+QM,S),demonstrating the intrinsic electron allocation at the *** Ov,Tiad.,and *** exhibited similar slopes(Ke),relatively steeper than that of *** means in the scope of Au NP charge state,the *** *** have a close electron-donating ability with Ov,but the ObrH donates relatively fewer *** linear relationship can be extended approximately to other *** higher the metal work function,the steeper the Ke for easier electron donation from defective *** stronger the metal oxygen affinity,the more positive the intercept(QM,S).That explains the easy generation of metallic or negative Pt and Au NPs on r-TiO_(2−x),but hard for Cu and Zn in *** provides theoretical guidance for regulating the charge of metal NPs over TiO_(2−x)supports.

关键词： metal-support interaction titanium oxide oxygen vacancy surface hydroxyl titanium adatom

In-situ measurement via the flow-through method and numerical simulations for radon exhalation during measurements of the radon exhalation rate

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Nuclear Science and Techniques 2024年第7期35卷 192-207页

作者： Ming xia Yong-Jun Ye Shan-Wei Shang Ting yu Dai-Jia Chen School of Resources Environment and Safety Engineering University of South ChinaHengyang421001China Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy University of South ChinaHengyang421001China

Small-scale measurements of the radon exhalation rate using the flow-through and closed-loop methods were conducted on the surface of a uranium tailing pond to better understand the differences between the two *** abnormal radon exhalation behavior was observed,leading to computational fluid dynamics(CFD)-based simulations in which dynamic radon migration in a porous medium and accumulation chamber was *** on the in-situ experimental and numerical simulation results,variations in the radon exhalation rate subject to permeability,flow rate,and insertion depth were quantified and *** in-situ radon exhalation rates measured using the flow-through method were higher than those measured using the closed-loop method,which could be explained by the negative pressure difference between the inside and outside of the chamber during the *** consistency of the variations in the radon exhalation rate between the experiments and simulations suggests the reliability of CFD-based techniques in obtaining the dynamic evolution of transient radon exhalation rates for diffusion and convection at the porous medium-air *** synergistic effects of the three factors(insertion depth,flow rate,and permeability)on the negative pressure difference and measured exhalation rate were quantified,and multivariate regression models were established,with positive correlations in most cases;the exhalation rate decreased with increasing insertion depth at a permeability of 1×10^(−11) m^(2).CFD-based simulations can provide theoretical guidance for improving the flow-through method and thus achieve accurate measurements.

关键词： Radon exhalation Flow-through Numerical simulation Accumulation chamber Multivariate regression

Effect of BaO and MgO on structure and properties of aluminate slag with various CaO/Al_(2)0_(3)ratios

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Journal of Iron and Steel Research International 2024年第1期31卷 204-214页

作者： yu-qi Kong Ting Wu Wen-zhi xia Wen Yang Hai-chuan Wang School of Metallurgical Engineering Anhui University of TechnologyMa’anshan243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resource Recycling(Ministry of Education) Anhui University of TechnologyMa’anshan243002AnhuiChina

To provide theoretical guidance for performance stability control of low-reactive mold fluxes,the effects of BaO and MgO on the structure and properties of aluminate slag with various CaO/Al_(2)0_(3)(C/A)ratios were investigated using the Fourier transform infrared spectrometer,Raman spectroscope,hemispherical melting point instrument,rotational viscometer and X-ray *** results indicated that with BaO and MgO addition,the structure polymerization was first weakened and then enhanced at C/A of 1.1,and the transition contents corresponded to 8 wt.%BaO and 2 wt.%MgO,respectively,while the structure polymerization decreased continuously at C/A of *** the viscosity change was well consistent with the structure evolution,the polymerization degree played a more prominent role in the slag viscosity than superheat degree when the melting temperature difference was within 40℃.The break temperature decreased initially and then increased with augment of BaO and MgO at C/A of 1.1,while it manifested a decrease trend with BaO addition,and it decreased obviously but then turned to increase with MgO increment at C/A of *** crystallization phase and crystallization ratio kept stable with BaO increment,while the crystallization ratio rose greatly with MgO promoting LiAlO_(2)precipitation at C/A of *** crystal types of all experimental slags were mainly Ca_(12)Al_(14)O_(33)and CaF_(2)at C/A of 1.3,and the precipitation of crystalline phase BaAl2O4 demonstrated a rising trend,while that of Ca_(12)Al_(14)O_(33)gradually declined with BaO augment.

关键词： Aluminate slag Structure MgO BaO Viscosity Property

Facile preparation of Fe/N-based biomass porous carbon composite towards enhancing the thermal decomposition of DAP-4

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Defence Technology（防务技术） 2024年第1期31卷 288-294页

作者： Er-hai An xiao-xia Li Cun-juan yu Ying-xin Tan Zi-jun Fan Qing-xia Li Peng Deng Xiong Cao School of Environment and Safety Engineering North University of ChinaTaiyuan030051PR China College of Safety and Emergency Management Engineering Taiyuan University of Science and TechnologyTaiyuan030024PR China

Fe/N-based biomass porous carbon composite(Fe/N-p Carbon) was prepared by a facile high-temperature carbonization method from biomass,and the effect of Fe/N-p Carbon on the thermal decomposition of energetic molecular perovskite-based material DAP-4 was *** porous carbonaceous materials was considered as the micro/nano support layers for in situ deposition of Fe/N ***/Np Carbon was prepared simply by the high-temperature carbonization *** was found that it showed the inherent catalysis properties for thermal decomposition of *** heat release of DAP-4/Fe/N-p Carbon by DSC curves tested had increased slightly,compared from DAP-4/Fe/N-p *** decomposition temperature peak of DAP-4 at the presence of Fe/N-p Carbon had reduced by 79°C from384.4°C(pure DAP-4) to 305.4°C(DAP-4/Fe/N-p Carbon-3).The apparent activation energy of DAP-4thermal decomposition also had decreased by 29.1 J/*** possible catalytic decomposition mechanism of DAP-4 with Fe/N-p Carbon was proposed.

关键词： Biomass materials Porous carbon DAP-4 Thermal decomposition Facile method

Approximate Synchronization of Multi-Agent Systems over Finite Fields

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Journal of Systems Science & Complexity 2024年第4期37卷 1561-1580页

作者： yu Miao FENG Jun-e xia Jianwei FU Shihua SHEN Hao School of Mathematical Sciences Liaocheng UniversityLiaocheng 252059China School of Mathematics Shandong UniversityJinan 250100China School of Electrical and Information Engineering Anhui University of TechnologyMaanshan 243002China

In this paper,the approximate synchronization of leader-follower multiagent systems(MASs) over finite fields is studied in regard to local and global ***,the approximately synchronous state set(ASSS) is ***,combined with ASSS and transient periods,some criteria for the local and global approximate synchronization of systems are ***,the algorithms for calculating the maximum approximately synchronous basin(MASB) and the maximum control invariant set(MCIS) are ***,the global approximate synchronization of the system is achieved by designing the state feedback control,and a design algorithm of the controller using the truth matrix method is ***,the results of approximate synchronization are degenerated to complete ***,two examples are shown to demonstrate the results of this paper.

关键词： Approximate synchronization finite field multiagent system semi-tensor product state feedback control

Enhancing reversible hydrogen storage performance of 2LiBH_(4)–MgH_(2)via in-situ building heterogeneous nucleation sites

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Rare Metals 2024年第9期43卷 4367-4376页

作者： Wei Chen Ya-Hui Sun Tian Xu Xue-Bin yu Guang-Lin xia Department of Materials Science Fudan UniversityShanghai 200433China

2LiBH_(4)-MgH_(2)composite is one of the most attractive reactive hydride composites with a theoretic hydrogen capacity of 10.8 wt%.However,the large nucleation restriction of MgB_(2)during the second step of dehydrogenation results in sluggish hydrogen storage kinetics and high operating temperature,which hinders its practical application as on-board hydrogen storage ***,Al3Ti doped Al nanoparticles(AT NPs)are prepared by a facile chemical reduction reaction to improve the hydrogen storage performance of 2LiBH_(4)-MgH_(2)*** the initial H_(2)desorption process,MgAlB_(4)and TiB_(2)that have identical crystal structure and low d-value mismatch with MgB_(2)resulting from the reaction between AT NPs and 2LiBH_(4)-MgH_(2)composite serve as effective nucleation sites for the formation of MgB_(2).As a result,the apparent activation energy of the two-step H_(2)desorption of AT NPs doped 2LiBH_(4)-MgH_(2)composite are notably decreased to(110.0±5.9)and(119.6±1.4)kJ·mol^(-1),which is 55.5 and 33.5 kJ·mol^(-1)lower than that of the undoped *** importantly,a reversible hydrogen storage capacity of 9.2 wt%after 10cycles of H_(2)desorption and adsorption could be achieved,corresponding to a capacity retention rate of 99%.The building of reactive bimetallic catalyst towards in situ formation of heterogeneous nucleation sites provides a new strategy for improving the hydrogen storage performance of reactive hydride composites.

关键词： Reversible hydrogen storage Reactive hydride composites Catalytic effects Heterogeneous nucleation

Molecular engineering binuclear copper catalysts for selective CO_(2) reduction to C_(2) products

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Journal of Energy Chemistry 2024年第6期93卷 166-173,I0005页

作者： Qi Zhao Kai Lei Bao yu xia Rachel Crespo-Otero Devis Di Tommaso Department of Chemistry School of Physical and Chemical SciencesQueen Mary University of LondonLondonE14NSUK Key Laboratory of Material Chemistry for Energy Conversion and Storage(Ministry of Education) Hubei Key Laboratory of Material Chemistry and Service FailureState Key Laboratory of Materials Processing and Die&Mould TechnologySchool of Chemistry and Chemical EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074HubeiChina Department of Chemistry University College LondonLondonWC1H 0AJUK Digital Environment Research Institute Queen Mary University of LondonEmpire HouseLondon E11HHUK

Molecular copper catalysts serve as exemplary models for correlating the structure-reaction-mechanism relationship in the electrochemical CO_(2) reduction(eCO_(2)R),owing to their adaptable environments surrounding the copper metal *** investigation,employing density functional theory calculations,focuses on a novel family of binuclear Cu molecular *** modulation of their coordination configuration through the introduction of organic groups aims to assess their efficacy in converting CO_(2) to C_(2)*** findings highlight the crucial role of chemical valence state in shaping the characteristics of binuclear Cu catalysts,consequently influencing the eCO_(2)R behaviour,Notably,the Cu(Ⅱ)Cu(Ⅱ)macrocycle catalyst exhibits enhanced suppression of the hydrogen evolution reaction(HER),facilitating proton trans fer and the eCO_(2)R *** rthermore,we explo re the impact of diverse electro n-withdrawing and electron-donating groups coordinated to the macrocycle(R=-F,-H,and-OCH_3)on the electron distribution in the molecular *** placement of-OCH_3 groups in the macrocycles leads to a favourable oxidation state of the Cu centres and subsequent C-C coupling to form C_(2) *** research provides fundamental insights into the design and optimization of binuclear Cu molecular catalysts for the electrochemical conversion of CO_(2) to value-added C_(2) products.

关键词： Molecular catalyst design Selective CO_(2)reduction C_(2)products Density functional theory calculations

Urinary metabolic profiles during Helicobacter pylori eradication in chronic gastritis

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World Journal of Clinical Cases 2024年第5期12卷 951-965页

作者： Wen-Ting An yu-xia Hao Hong-xia Li Xing-Kang Wu Department of Pharmacy Shanxi Provincial People’s HospitalTaiyuan 030012Shanxi ProvinceChina Department of Gastroenterology Shanxi Provincial People's HospitalTaiyuan 030012Shanxi ProvinceChina Department of Oncology Shanxi Provincial People’s HospitalTaiyuan 030012Shanxi ProvinceChina Modern Research Center for Traditional Chinese Medicine Shanxi UniversityTaiyuan 030006Shanxi ProvinceChina

BACKGROUND Helicobacter pylori(***)infection is a major risk factor for chronic gastritis,affecting approximately half of the global *** eradication is a popular treatment method for ***-positive chronic gastritis,but its mecha-nism remains *** metabolomics has been used to elucidate the mechanisms of gastric disease ***,no clinical study has been conducted on urinary metabolomics of chronic *** To elucidate the urinary metabolic profiles during *** eradication in patients with chronic *** We applied LC–MS-based metabolomics and network pharmacology to in-vestigate the relationships between urinary metabolites and ***-positive chronic gastritis via a clinical follow-up *** Our study revealed the different urinary metabolic profiles of ***-positive chronic gastritis before and after *** *** metabolites regulated by *** eradication therapy include cis-aconitic acid,isocitric acid,citric acid,L-tyrosine,L-phenylalanine,L-tryptophan,and hippuric acid,which were involved in four metabolic pathways:(1)Phenylalanine metabolism;(2)phenylalanine,tyrosine,and tryptophan biosynthesis;(3)citrate cycle;and(4)glyoxylate and dicarboxylate *** metabolomics and network pharmacology revealed that MPO,COMT,TPO,TH,EPX,CMA1,DDC,TPH1,and LPO were the key proteins involved in the biological progress of *** eradication in chronic *** Our research provides a new perspective for exploring the significance of urinary metabolites in evaluating the treatment and prognosis of ***-positive chronic gastritis patients.

关键词： LC-MS metabolomics chronic gastritis Helicobacter pylori urinary metabolites