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Enhancing hydrogen storage performance via optimizing Y and Ni element in magnesium alloy

Journal of Magnesium and Alloys 2022年第3期10卷 888-903页

作者： Xu Pang Lei Ran Yu'an Chen Yuxiao Luo Fusheng Pan College of materials Science and engineering Chongqing UniversityChongqing 400044China National Engineering Research for magnesium Alloys Chongqing UniversityChongqing 400044China Guangdong Guoyan Science and Technology Research Center Co. LtdGuangdong 518000China

Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost.In this paper,Mg_(91.4)Ni_(7)Y_(1.6) and Mg_(92.8)Ni_(2.4)Y_(4.8) alloys were prepared by melting and ball milling.Their microstructures and phases were characterized by X-ray diffraction,scanning electron microscope and transmission electron microscope,and hydrogen absorbing and desorbing properties were tested by the high pressure gas adsorption apparatus and differential scanning calorimetry(DSC).In order to estimate the activation energy and growth mechanism of alloy hydride,the JMAK,Arrhenius and Kissinger methods were applied for calculation.The hydrogen absorption content of Mg_(92.8)Ni_(2.4)Y_(4.8) alloy reaches 3.84 wt.%within 5 min under 350℃,3 MPa,and the maximum hydrogen capacity of the alloy is 4.89 wt.%in same condition.However,the hydrogen absorption of Mg_(91.4)Ni_(7)Y_(1.6) alloy reaches 5.78 wt.%within 5 min,and the maximum hydrogen absorption of the alloy is 6.44 wt.%at 350℃and 3 MPa.The hydrogenation activation energy of Mg_(94.4)Ni_(7)Y_(1.6) alloy is 25.4 kJ/mol H_(2),and the enthalpy and entropy of hydrogen absorption are-60.6 kJ/mol H_(2) and 105.5 J/K/mol H_(2),separately.The alloy begins to dehydrogenate at 210℃,with the dehydrogenation activation energy of 87.7 kJ/mol H_(2).By altering the addition amount of Ni and Y elements,the 14 H-LPSO phase with smaller size and ternary eutectic areas with high volume fraction are obtained,which provides more phase boundaries and catalysts with better dispersion,and there are a lot of fine particles in the alloy,these structures are beneficial to enhance the hydrogen storage performance of the alloys.

关键词： Hydrogen storage materials LPSO phase Catalytic effect Hydrogen storage performance

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Study on a conical bearing for acceleration-sensitive equipment

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 103-128页

作者： pang Hui xu Wen Dai Junwu Jiang Tao Key Laboratory of Earthquake Engineering and Engineering Vibration Institute of Engineering MechanicsChina Earthquake AdministrationHarbin 150080China Key Laboratory of Earthquake Disaster Mitigation Ministry of Emergency ManagementHarbin 150080China School of Civil Engineering and Transportation Beihua UniversityJilin 132013China

Seismic isolation effectively reduces seismic demands on building structures by isolating the superstructure from ground vibrations during earthquakes.However,isolation strategies give less attention to acceleration-sensitive systems or equipment.Meanwhile,as the isolation layer’s displacement grows,the stiffness and frequency of traditional rolling and sliding isolation bearings increases,potentially causing self-centering and resonance concerns.As a result,a new conical pendulum bearing has been selected for acceleration-sensitive equipment to increase self-centering capacity,and additional viscous dampers are incorporated to enhance system damping.Moreover,the theoretical formula for conical pendulum bearings is supplied to analyze the device’s dynamic parameters,and shake table experiments are used to determine the proposed device’s isolation efficiency under various conditions.According to the test results,the newly proposed devices have remarkable isolation performance in terms of minimizing both acceleration and displacement responses.Finally,a numerical model of the isolation system is provided for further research,and the accuracy is demonstrated by the aforementioned experiments.

关键词： seismic isolation acceleration-sensitive equipment the conical pendulum bearing shake table tests isolation performance,numerical model

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Multicolor luminescence of hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) microcrystals with tunable morphology under 940 nm excitation for temperature-responsive anti-counterfeiting

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Journal of Rare Earths 2022年第3期40卷 406-414,I0002页

作者： Lingna xu Hongyan Zheng Tao pang Junwen Mao College of Science Huzhou UniversityHuzhou 313000China

In this study,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) microcrystals were synthesized controllably,and upconversion luminescence excited at 940 nm and its application in temperature-responsive anti-counterfeiting are reported.It is clarified that the Ln^(3+)(Ln=Y+Yb+Ho+Ce)density ratio of bottom plane to side plane in the unit cell can be regulated by Ce^(3+) doping.It is also proved that the energy transfer of Yb^(3+) to Ho^(3+) is responsible for the activation of Ho^(3+)under 940 nm excitation,while the cross relaxation between Ho^(3+)and Ce^(3+)participates in the redistribution of electron population of^(5)S_(2)/^(5)F_(4)and^(5)F_(5)levels.Both theory and experiment confirm that the intensity ratio of red to green emission(I_(R)/I_(G))as a function of temperature as an independent variable has good linear characteristics in the temperature range of 300-500 K.Due to the good responsiveness of multicolor luminescence to temperature,the hexagonal NaYF_(4):Yb^(3+)/Ho^(3+)/Ce^(3+) with tunable morphology is a promising candidate for advanced temperature-responsive upconversion anti-counterfeiting.Our results provide a new pathway for the controllable synthesis of hexagonal NaYF_(4)microcrystals as well as the regulation of upconversion luminescence that is excited by wavelengths other than 980 nm and its application in anti-counterfeiting.

关键词： Upconversion luminescence Color regulation Anti-counterfeiting Rare earths

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Application of a microscopic optical potential of chiral effective field theory in (p, d) transfer reactions

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Nuclear Science and Techniques 2024年第1期35卷 134-144页

作者： Yi-Ping xu Si-Lu Chen Dan-Yang pang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China School of Physics Beihang UniversityBeijing 100191China

The microscopic global nucleon–nucleus optical model potential(OMP)proposed by Whitehead,Lim,and Holt,the WLH potential(Whitehead et al.,Phys Rev Lett 127:182502,2021),which was constructed in the framework of many-body per-turbation theory with state-of-the-art nuclear interactions from chiral effective field theory(EFT),was tested with(p,d)transfer reactions calculated using adiabatic wave approximation.The target nuclei included both stable and unstable nuclei,and the incident energies reached 200 MeV.The results were compared with experimental data and predictions using the phenomenological global optical potential of Koning and Delaroche,the KD02 potential.Overall,we found that the micro-scopic WLH potential described the(p,d)reaction angular distributions similarly to the phenomenological KD02 potential;however,the former was slightly better than the latter for radioactive targets.On average,the obtained spectroscopic factors(SFs)using both microscopic and phenomenological potentials were similar when the incident energies were below approxi-mately 120 MeV.However,their difference tended to increase at higher incident energies,which was particularly apparent for the doubly magic target nucleus 40Ca.

关键词： Microscopic optical model potential (p,d)transfer Spectroscopic factors

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Mechanism and design of allosteric activators of SIRT1

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Protein & Cell 2023年第5期14卷 387-392页

作者： Fei Liu Ningning pang Rui-Ming xu Na Yang State Key Laboratory of Medicinal Chemical Biology College of Pharmacy and Key Laboratory of Medical Data Analysis and Statistical Research of TianjinNankai UniversityTianjin 300353China National Laboratory of Biomacromolecules CAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China

Dear Editor,The sirtuin family Nicotinamide adenine dinucleotide-dependent deacetylases have important roles in many biological processes(Milne and Denu,2008).SIRT1 is a mammalian homolog of yeast Sir2,which is the founding member of the sirtuin family.Many SIRT1 substrates have been reported,including histones,p53,FOXOs,and PGC1α(Hsu et al.,2013).Stimulating the activity of SIRT1 has been shown to be an attractive therapeutic strategy for various physiological and pathological conditions such as aging,metabolic disorders,inflammation,and neurodegeneration(Guarente,2011).Several small molecules have been identified or developed as potential sirtuinactivating compounds(STACs).Most notably,resveratrol,a natural STAC,was shown to activate the SIRT1-catalyzed deacetylation of the Fluor de Lys(FDL)peptide,which is a p53 peptide fused to a 7-amino-4-methylcoumarin(AMC)fluorophore at the C-terminus(Table S1;Howitz et al.,2003).However,the activation of deacetylation of the p53 peptide is dependent on the presence of the AMC fluorophore(Borra et al.,2005;Wu et al.,2013).

关键词： SIRT1 PGC1α

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Resource allocation for sum-rate maximization in NOMA-based generalized spatial modulation

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Digital Communications and Networks 2022年第6期8卷 1077-1084页

作者： Guoquan Li Zijie Hong Yu pang Yongjun xu Zhengwen Huang School of Communication and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing400065China Chongqing Key Laboratory of Photoelectronic Information Sensing and Transmitting Technology Chongqing400065China Department of Electronic and Electrical Engineering Brunel University LondonLondonUB8-3PHUK

The Multiple-Input Multiple-Output(MIMO)Non-Orthogonal Multiple Access(NOMA)based on Spatial Modulation(SM-MIMO-NOMA)system has been proposed to achieve better spectral efficiency with reduced radio frequency chains comparing to the traditional MIMO-NOMA system.To improve the performance of SM-MIMO-NOMA systems,we extend them to generalized spatial modulation scenarios while maintaining moderate complexity and fairness.In this paper,system spectral efficiency and transmission quality improvements are proposed by investigating a sum-rate maximization resource allocation problem that is subject to the total transmitted power,user grouping,and resource block constraints.To solve this non-convex and difficult problem,a graph-based user grouping strategy is proposed initially to maximize the mutual gains of intragroup users.An auxiliary-variable approach is then adopted to transform the power allocation subproblem into a convex one.Simulation results demonstrate that the proposed algorithm has better performance in terms of bit error rate and sum rates.

关键词： Resource allocati on NOMA Spatial modulati on Power allocation User grouping

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Low-dimensional MXenes as noble metal-free co-catalyst for solar-to-fuel production:Progress and prospects

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Journal of Materials Science & Technology 2022年第19期114卷 143-164页

作者： Wanying Lei Tong Zhou Xin pang Shixiang xue Quanlong xu College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Key laboratory of Carbon Materials of Zhejiang Province Wenzhou UniversityWenzhou 325027China

Direct conversion of solar energy into chemical fuels via semiconducting materials through photocatalytic technology is a sustainable way to tackle the global warming, environmental issue and energy crisis. Transition metal carbides and nitrides(MXenes), a newly emerging class of 2D layered materials, has gained tremendous attention as a noble metal-free co-catalyst for boosting photoreactivity due to its extraordinary characteristics like elemental abundance, excellent electrical conductivity, abundant surface functional groups, unique hydrophilic behavior and flexible modulation of chemical composition. The rational integration of low-dimensional MXenes in the form of 2D layered structures or 0D quantum dots with diverse semiconducting materials offer more versatile and robust heterostructured-photocatalysts that are applicable in solar fuel generation. Herein, we summarize the recent advances and achievements in the synthesis of low-dimensional MXenes and their application in hydrogen production from water splitting and CO_(2) photoreduction. A comprehensive discussion of the fundamentals for solar fuel production, synthesis strategies and theoretical calculations for MXenes-based photocatalysts are also given. Finally, the existing challenges and further perspectives of MXenes-based nanostructures for efficient solar fuel production are addressed.

关键词： MXenes Low-dimensional materials Co-catalyst Photocatalytic H_(2)evolution CO_(2)photoreduction

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Global Existence and Finite Time Blow-up for the m-Laplacian Parabolic Problem

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Acta Mathematica Sinica,English Series 2023年第8期39卷 1497-1524页

作者： Yue pang Vicentiu D.RADULESCU Run Zhang xu College of Mathematical Sciences Harbin Engineering UniversityHarbin 150001P.R.China Faculty of Applied Mathematics AGH University of Science and Technology30-059 Krak´owPoland Department of Mathematics University of CraiovaStreet A.I.Cuza No.13200585 CraiovaRomania

In this paper,we consider an initial boundary value problem of m-Laplacian parabolic equation arising in various physical models.We tackle this problem at three different initial energy levels.For the sub-critical initial energy,we obtain the blow-up result and estimate the lower and upper bounds of the blow-up time.For the critical initial energy,we show the global existence,asymptotic behavior,finite time blow-up and the lower bound of the blow-up time.For the sup-critical initial energy,we prove the finite time blow-up and estimate the lower and upper bounds of the blow-up time.

关键词： m-Laplacian parabolic equation blow-up blow-up time global existence

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A 3D hierarchical electrocatalyst:Core–shell Cu@Cu(OH)_(2)nanorods/MOF octahedra supported on N-doped carbon for oxygen evolution reaction

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Nano Research 2023年第5期16卷 8012-8017页

作者： Xinran Li Yipei Li Changli Wang Huaiguo xue Huan pang Qiang xu School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225009China Shenzhen Key Laboratory of Micro/Nano-Porous Functional Materials(SKLPM) SUSTech-Kyoto University Advanced Energy Materials Joint Innovation Laboratory(SKAEM-JIL)Key University Laboratory of Highly Efficient Utilization of Solar Energy and Sustainable Development of GuangdongDepartment of ChemistryDepartment of Materials Science and Engineering and SUSTech Academy for Advanced Interdisciplinary StudiesSouthern University of Science and Technology(SUSTech)Shenzhen 518055China

Cu-based materials are seldom reported as oxygen evolution reaction(OER)electrocatalysts due to their inherent electron orbital configuration,which makes them difficult to adsorb oxygen-intermediates during OER.Reasonably engineering the hierarchical architectures and the electronic structures can improve the performance of Cu-based OER catalysts,such as constructing multilevel morphology,inducing the porous materials,improving the Cu valence,building heterostructures,doping heteroatoms,etc.In this work,copper-1,3,5-benzenetricarboxylate(HKUST-1)octahedra in-situ grow on the Cu nanorod(NR)-supported N-doped carbon microplates,meanwhile an active layer of Cu(OH)_(2)forms on the surface of the original conductive Cu NRs.The octahedral HKUST-1,serving as a spacer between the microplates,greatly improves the porosity and increases the available active sites,facilitating the mass transport and electron transfer,thus resulting in greatly enhanced OER performance.

关键词： core–shell nanorod Cu@Cu(OH)_(2) metal–organic framework oxygen evolution reaction

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A Class of New Quadratic Vectorial Bent Functions

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Chinese Journal of Electronics 2020年第5期29卷 873-879页

作者： pang Tingting ZENG Xiangyong LI Nian xu Yunge The Faculty of Mathematics and Statistics Hubei Key Laboratory of Applied Mathematics Hubei University

A class of quadratic vectorial bent functions having the form F（x）=Tr;(ax;2;+1))+Tr;(bx;2;+1)) is investigated,where n,m,s;,s;are positive integers and the coefficients a,b belong to the finite field F;.Through some discussions on the permutation property of certain linearized polynomials over F;,several classes of quadratic vectorial bent functions are presented for special cases of n,and it is also verified by computer that some vectorial bent functions proposed are extended affine inequivalent to all known quadratic vectorial bent functions.

关键词： Vectorial bent function Permutation polynomial Extended affine equivalence Finite field

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