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Chinese Physics Letters 2004年第6期21卷 1171-1174页

作者： M.Khalid K.M.Khan A.U.qaisrani q.n.malik DepartmentofPhysics GomalUniversityDeraIsmailKhanPakistan nuclearPhysicsDivision PakistanInstituteofNuclearScienceandTechnology(PINSTECH)P.O.NiloreIslamabadPakistan

We investigate the effect of the ballistic mechanism on the phase diagram using a square surface. While using this mechanism whenever an O2 molecule hits a randomly vacant selected site, the molecule breaks up into atomic form and then executes a ballistic flight. The paths of the two oxygen atoms are taken exactly to be opposite to each other, ***-parallel, and the ranges of the atoms are taken to be equal, *** may fly up to 1 or 1.414 or 2 of the atomic spacing from the site of impact. Four cases have been studied on the basis of the range of hot atoms. The range of the hot oxygen atoms executing a ballistic flight might be up to the first nearest neighbourhood (1 atomic spacing from the site of impact), the second nearest neighbourhood (1.414 atomic spacing from the site of impact), the third nearest neighbourhood (2 atomic spacing from the site of impact), known as cases a, b, and c, respectively, while for case d the range of the oxygen atoms executing the ballistic flight might be up to 1 atomic spacing or 1.414 atomic spacing or 2 atomic spacing from the site of impact. The steady reactive window is observed and the continuous transition disappears. As soon as the CO partial pressure departs from zero, the production of CO2 is observed, which clearly verifies the experimental observation.

关键词： Oxygen

Effect of Al_(2)O_(3)on the Mechanical Properties of(B_(4)C+Al_(2)O_(3))/Al neutron Absorbing Materials

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Acta Metallurgica Sinica(English Letters) 2024年第8期37卷 1411-1420页

作者： J.X.Cai B.M.Shi n.Li Y.Liu Z.G.Zhang Y.n.Zan q.Z.Wang B.L.Xiao Z.Y.Ma Shi‑Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Key Laboratory of nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China nuclear Equipment Division Beijing Institute of Nuclear EngineeringChina Nuclear Power Engineering Co.Ltd.Beijing 100840China Department of Materials Science School of Mechanical EngineeringShenyang UniversityShenyang 110044China

B_(4)C/Al composites are widely utilized as neutron absorbing materials for the storage and transportation of spent nuclear *** order to improve the high-temperature mechanical properties of B_(4)C/Al composites,in-situ nano-Al_(2)O_(3)was introduced utilizing oxide on Al powder *** this study,the Al_(2)O_(3)content was adjusted by utilizing spheroid Al powder with varying diameters,thereby investigating the impact of Al_(2)O_(3)content on the tensile properties of(B_(4)C+Al_(2)O_(3))/Al *** was found that the pinning effect of Al_(2)O_(3)on the grain boundaries could hinder the recovery of dislocations and lead to dislocation accumulation at high *** the result,with the increase in Al_(2)O_(3)content and the decrease in grain size,the high-temperature strength of the composites increased *** finest Al powder used in this investigation had a diameter of 1.4μm,whereas the resultant composite exhibited a maximum strength of 251 MPa at room temperature and 133 MPa at 350℃,surpassing that of traditional B_(4)C/Al composites.

关键词： Al matrix composites neutron absorbing materials (B_(4)C+Al_(2)O_(3))/Al composites High-temperature strength

Generation of polarized electron beams through self-injection in the interaction of a laser with a pre-polarized plasma

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High Power Laser Science and Engineering 2024年第3期12卷 62-68页

作者： L.R.Yin X.F.Li Y.J.Gu n.Cao q.Kong M.Büscher S.M.Weng M.Chen Z.M.Sheng Key Laboratory of nuclear Physics and Ion-beam Application(MoE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan UniversityShanghaiChina State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina SAnKEn(Institute of Scientific and Industrial Research) Osaka UniversityOsakaJapan Sichuan Research Institute Shanghai Jiao Tong UniversityChengduChina Peter Grünberg Institut(PGI-6) Forschungszentrum JülichJülichGermany Institut für Laser-und Plasmaphysik Heinrich-Heine-Universität DüsseldorfDüsseldorfGermany Key Laboratory for Laser Plasmas(MoE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghaiChina Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghaiChina

Polarized electron beam production via laser wakefield acceleration in pre-polarized plasma is investigated by particlein-cell *** evolution of the electron beam polarization is studied based on the Thomas±Bargmann±Michel±Telegdi equation for the transverse and longitudinal self-injection,and the depolarization process is found to be influenced by the injection *** the case of transverse self-injection,as found typically in the bubble regime,the spin precession of the accelerated electrons is mainly influenced by the ***,in the case of longitudinal injection in the quasi-1D regime(for example,*** et al.,***.110,135002(2013)),the direction of electron spin oscillates in the laser *** the electrons move around the laser axis,the net influence of the laser field is nearly zero and the contribution of the wakefield can be ***,an ultra-short electron beam with polarization of 99%can be obtained using longitudinal self-injection.

关键词： laser wakefield acceleration longitudinal self-injection particle-in-cell simulation polarized electron beam

Frilled Lizard Optimization: A novel Bio-Inspired Optimizer for Solving Engineering Applications

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Computers, Materials & Continua 2024年第6期79卷 3631-3678页

作者： Ibraheem Abu Falahah Osama Al-Baik Saleh Alomari Gulnara Bektemyssova Saikat Gochhait Irina Leonova OmParkash malik Frank Werner Mohammad Dehghani Department of Mathematics Faculty of ScienceThe Hashemite UniversityP.O.Box 330127Zarqa13133Jordan Department of Software Engineering Al-Ahliyya Amman UniversityAmman19328Jordan Faculty of Science and Information Technology Software EngineeringJadara UniversityIrbid21110Jordan Department of Computer Engineering International Information Technology UniversityAlmaty050000Kazakhstan Symbiosis Institute of Digital and Telecom Management Constituent of Symbiosis International Deemed UniversityPune412115India neuroscience Research Institute Samara State Medical UniversitySamara443001Russia Faculty of Social Sciences Lobachevsky UniversityNizhny Novgorod603950Russia Department of Electrical and Software Engineering University of CalgaryCalgaryAB T2N 1N4Canada Faculty of Mathematics Otto-von-Guericke UniversityP.O.Box 4120Magdeburg39016Germany Department of Electrical and Electronics Engineering Shiraz University of TechnologyShiraz***Iran

This research presents a novel nature-inspired metaheuristic algorithm called Frilled Lizard Optimization(FLO),which emulates the unique hunting behavior of frilled lizards in their natural *** draws its inspiration from the sit-and-wait hunting strategy of these *** algorithm’s core principles are meticulously detailed and mathematically structured into two distinct phases:(i)an exploration phase,which mimics the lizard’s sudden attack on its prey,and(ii)an exploitation phase,which simulates the lizard’s retreat to the treetops after *** assess FLO’s efficacy in addressing optimization problems,its performance is rigorously tested on fifty-two standard benchmark *** functions include unimodal,high-dimensional multimodal,and fixed-dimensional multimodal functions,as well as the challenging CEC 2017 test ***’s performance is benchmarked against twelve established metaheuristic algorithms,providing a comprehensive comparative *** simulation results demonstrate that FLO excels in both exploration and exploitation,effectively balancing these two critical aspects throughout the search *** balanced approach enables FLO to outperform several competing algorithms in numerous test ***,FLO is applied to twenty-two constrained optimization problems from the CEC 2011 test suite and four complex engineering design problems,further validating its robustness and versatility in solving real-world optimization ***,the study highlights FLO’s superior performance and its potential as a powerful tool for tackling a wide range of optimization problems.

关键词： Optimization engineering bio-inspired metaheuristic frilled lizard exploration exploitation

A data-driven reduced-order model for stiff chemical kinetics using dynamics-informed training

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Energy and AI 2024年第1期15卷 181-192页

作者： Vijayamanikandan Vijayarangan Harshavardhana A.Uranakara Shivam Barwey Riccardo Malpica Galassi Mohammad Rafi malik Mauro Valorani Venkat Raman Hong G.Im CCRC King Abdullah University of Science and TechnologyThuwalSaudi Arabia Argonne Leadership Computing Facility Argonne National LaboratoryLemontIL 60439USA Mechanical and Aerospace Engineering Department Sapienza University of RomeVia Eudossiana18Rome 00184Italy Department of Aerospace Engineering University of MichiganAnn ArborMI 48109USA

A data-based reduced-order model(ROM)is developed to accelerate the time integration of stiff chemically reacting systems by effectively removing the stiffness arising from a wide spectrum of chemical time ***,the objective of this work is to develop a ROM that acts as a non-stiff surrogate model for the time evolution of the thermochemical state vector(temperature and species mass fractions)during an otherwise highly stiff and nonlinear ignition *** model follows an encode-forecast-decode strategy that combines a nonlinear autoencoder(AE)for dimensionality reduction(encode and decode steps)with a neural ordinary differential equation(nODE)for modeling the dynamical system in the AE-provided latent space(forecasting step).By means of detailed timescale analysis by leveraging the dynamical system Jacobians,this work shows how data-based projection operators provided by autoencoders can inherently construct the latent spaces by removing unnecessary fast timescales,even more effectively than physics-based counterparts based on an eigenvalue analysis.A key finding is that the most significant degree of stiffness reduction is achieved through an end-to-end training strategy,where both AE and neural ODE parameters are optimized simultaneously,allowing the discovered latent space to be *** addition to end-to-end training,this work highlights the vital contribution of AE nonlinearity in the stiffness reduction *** the prediction of homogeneous ignition phenomena for H2-air and C2H4-air mixtures,the proposed ROM achieves several ordersof-magnitude increase in the integration time step size when compared to(a)a baseline CVODE solver for the full-chemical system,(b)statistical technique–principal component analysis(PCA),and(c)computational singular perturbation(CSP),a vetted physics-based stiffness-reducing modeling framework.

关键词： Stiff system Chemical kinetics Reacting flows Autoencoders neural ODE

Transfer learning framework for multi-scale crack type classification with sparse microseismic networks

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International Journal of Mining Science and Technology 2024年第2期34卷 167-178页

作者： Arnold Yuxuan Xie Bing qLi Department of Civil and Environmental Engineering Western UniversityLondon N6A 3K7Canada

Rock fracture mechanisms can be inferred from moment tensors(MT)inverted from microseismic ***,MT can only be inverted for events whose waveforms are acquired across a network of *** is limiting for underground mines where the microseismic stations often lack azimuthal ***,there is a need for a method to invert fracture mechanisms using waveforms acquired by a sparse microseismic ***,we present a novel,multi-scale framework to classify whether a rock crack contracts or dilates based on a single *** framework consists of a deep learning model that is initially trained on 2400000+manually labelled field-scale seismic and microseismic waveforms acquired across 692 *** learning is then applied to fine-tune the model on 300000+MT-labelled labscale acoustic emission waveforms from 39 individual experiments instrumented with different sensor layouts,loading,and rock types in *** optimal model achieves over 86%F-score on unseen waveforms at both the lab-and *** model outperforms existing empirical methods in classification of rock fracture mechanisms monitored by a sparse microseismic *** facilitates rapid assessment of,and early warning against,various rock engineering hazard such as induced earthquakes and rock bursts.

关键词： Multi-scale Fracture processes Microseismic Acoustic emission Source mechanism Deep learning

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硅硼碳氮陶瓷前驱体聚硼硅氮烷的合成与表征

Journal of Donghua University(English Edition) 2024年第3期41卷 257-262页

作者： malik Hamza 申键唐滋成刘勇东华大学材料科学与工程学院纤维材料改性国家重点实验室上海201620 东华大学高性能纤维及制品教育部重点实验室上海201620

以三氯化硼(BCl3)、三氯硅烷(HSiCl3)和六甲基二硅氮烷(Me6Si2nH)为原料,通过聚合物前驱体转化陶瓷(polymer-derived ceramics,PDCs)法成功合成了硅硼碳氮(SiBnC)陶瓷前驱体--聚硼硅氮烷(PBSZ)。采用傅里叶变换红外光谱、核磁共振、X射... 详细信息

以三氯化硼(BCl3)、三氯硅烷(HSiCl3)和六甲基二硅氮烷(Me6Si2nH)为原料,通过聚合物前驱体转化陶瓷(polymer-derived ceramics,PDCs)法成功合成了硅硼碳氮(SiBnC)陶瓷前驱体--聚硼硅氮烷(PBSZ)。采用傅里叶变换红外光谱、核磁共振、X射线光电子能谱、热重分析和差示扫描量热对PBSZ的结构和热性能进行分析。结果表明,PBSZ结构中存在硅氮硼(Si—n—B)网络和六元硼氮(B—n)环。在氮气中,800℃时PBSZ的陶瓷产率为53.9%。

关键词：硅硼碳氮(SiBnC)陶瓷陶瓷前驱体聚硼硅氮烷(PBSZ) 聚合物前驱体转化陶瓷(PDCs)法

Selective Hydrodeoxygenation of Lignin-Derived Vanillin via Hetero-Structured High-Entropy Alloy/Oxide Catalysts

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Energy & Environmental Materials 2024年第3期7卷 202-210页

作者： Yan Sun Kaili Liang Ren Tu Xudong Fan Charles q.Jia Zhiwen Jia Yingnan Li Hui Yang Enchen Jiang Hanwen Liu Yonggang Yao Xiwei Xu Key Laboratory for Biobased Materials and Energy of Ministry of Education College of Materials and EnergySouth China Agricultural UniversityGuangzhou 510640China Department of Chemical Engineering and Applied Chemistry University of Toronto200 College StreetToronto ON M5S3E5Canada State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The chemoselective hydrodeoxygenation of natural lignocellulosic materials plays a crucial role in converting biomass into value-added *** their complex molecular structures often require multiple active sites synergy for effective activation and achieving high ***,it is reported that a high-entropy alloy(HEA)on high-entropy oxide(HEO)hetero-structured catalyst for highly active,chemoselective,and robust vanillin *** heterogenous HEA/HEO catalysts were prepared by thermal reduction of senary HEOs(niZnCuFeAlZrO_(x)),where exsolvable metals(e.g.,ni,Zn,Cu)in situ emerged and formed randomly dispersed HEA nanoparticles anchoring on the HEO *** catalyst exhibits excellent catalytic performance:100%conversion of vanillin and 95%selectivity toward high-value 2-methyl-4 methoxy phenol at low temperature of 120℃,which were attributed to the synergistic effect among HEO matrix(with abundant oxygen vacancies),anchored HEA nanoparticles(having excellent hydrogenolysis capability),and their intimate hetero-interfaces(showing strong electron transferring effect).Therefore,our work reported the successful construction of HEA/HEO heterogeneous catalysts and their superior multifunctionality in biomass conversion,which could shed light on catalyst design for many important reactions that are complex and require multifunctional active sites.

关键词： biomass conversion heterogeneous catalysts high-entropy oxide high-entropy alloys lignin pyrolysis

Rare earth based MgPm_(2)X_(4)(X=S,Se) spinel chalcogenides for spintronic and thermoelectric applications

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Journal of Rare Earths 2024年第8期42卷 1577-1585,I0006页

作者： Tariq M.Al-Daraghmeh Omar Zayed Ghulam M.Mustafa Taharh Zelai Bisma Younas Hind Albalawi S.Bouzgarrou Othman Hakami q.Mahmood Khaild I.Hussein Basic Sciences Department King Abdullah Ⅱ School of EngineeringPrincess Sumaya University For TechnologyP.O.Box 1438Al-jubaiha11941AmmanJordan Department of Physics Division of Science&TechnologyUniversity of EducationLahorePakistan Department of Physics Faculty of ScienceJazan University JazanSaudi Arabia Department of Physics The University of LahoreLahorePakistan Department of Physics College of SciencesPrincess Nourah bint Abdulrahman University(PNU)P.O.Box 84428Riyadh11671Saudi Arabia Department of Physics College of ScienceQassim UniversityPo.64BuraidahSaudi Arabia Laboratoire de Microelectronique et Instrumentation(UR 03/13-04) Faculte des Sciences de MonastirAvenue de I'Environnement 5000MonastirTunisia Department of Chemistry Faculty of ScienceJazan University JazanSaudi Arabia Basic&Applied Scientific Research Center Department of PhysicsCollege of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam 31441Saudi Arabia Department of Radiological Sciences College of Applied Medical SciencesKing Khalid UniversityAbha61421Saudi Arabia

In current report,the structural,magnetic,and thermoelectric properties of RE doped MgPm_(2)X_(4)(X=S,Se) spinels were *** energy difference in ferromagnetic and antiferromagnetic states reveals the stability of MgPm_(2)(S/Se)_(4) in the ferromagnetic *** co mputation of enthalpy of formation also ascertains thermodynamic stability of crystal ***-dependent band structure and density of states analysis reveal ferromagnetic semiconducting character showing different electronic behavior in both spin *** room temperature ferromagnetism,spin polarization and Curie temperature are estimated from exchange energies *** addition,exchange constants(n_(0)α and n_(0)β),exchange energy Δ_(x)(pd),crystal ifeld energy,and double exchange mechanism were studied to explore the magnetic ***,the electrical conductivity,thermal conductivity,Seebeck co-efficient,and power factor show effect on electrons spin and their potential for thermoelectric devices.

关键词： Rare earth elements Spintronic applications Thermoelectric effects Exchange energies

numerical analysis of high‑speed railway slab tracks using calibrated and validated 3D time‑domain modelling

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Railway Engineering Science 2024年第1期32卷 36-58页

作者： A.F.Esen O.Laghrouche P.K.Woodward D.Medina‑Pineda q.Corbisez J.Y.Shih D.P.Connolly Institute for High‑Speed Rail and System Integration University of LeedsLeeds LS29JTUK Institute for Infrastructure and Environment Heriot-Watt UniversityEdinburgh EH144ASUK Alstom Transport Saint‑OuenFrance Birmingham Centre for Railway Research and Education University of BirminghamBirmingham B152TTUK

Concrete slabs are widely used in modern railways to increase the inherent resilient quality of the tracks,provide safe and smooth rides,and reduce the maintenance *** this paper,the elastic performance of a novel slab trackform for high-speed railways is investigated using three-dimensional finite element modelling in *** is then compared to the performance of a ballasted ***,slab and ballasted track models are developed to replicate the full-scale testing of track *** the models are calibrated with the experimental results,the novel slab model is developed and compared against the calibrated slab track *** slab and ballasted track models are then extended to create linear dynamic models,considering the track geodynamics,and simulating train passages at various speeds,for which the Ledsgard documented case was used to validate the *** travelling at low and high speeds are analysed to investigate the track deflections and the wave propagation in the soil,considering the issues associated with critical *** train loading methods are discussed,and the most practical approach is retained and ***,correlations are made between the geotechnical parameters of modern high-speed rail and conventional *** is found that considering the same ground condition,the slab track deflections are considerably smaller than those of the ballasted track at high speeds,while they show similar behaviour at low speeds.

关键词： High-speed railways Slab track new ballastless track Ballasted track Critical speeds Finite element modelling Calibration of numerical models