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Synthesis and characterization of three new solid polyoxometalates based on Wells-Dawson-derived sandwich-type polyanions [Co_(4)(H_(2)O)_(2)(P_(2)W_(15)O_(56))_(2)]^(16-)

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第3期25卷 268-274页

作者： Jjijie YE Xuan XU Chuande WU department of Chemistry Zhejiang UniversityHangzhou 310058China

Three polyoxometalate-based hybrid coordination materials,[Co_(8)(H_(2)O)_(34)(pz)_(2){Co_(4)(H_(2)O)_(2)P_(4)W_(30)O_(112)}]·16H_(2)O(compound 1),[H_(3)O]_(4)[Co_(6)(H_(2)O)_(22)(pz)_(2){Co_(4)(H_(2)O)_(2)P_(4)W_(30)O_(112)}]·21H_(2)(compound 2),and[H_(3)O]_(4)[Co_(6)(H_(2)O)_(22){Co_(4)(H_(2)O)_(2)P_(4)W_(30)O_(112)}]·29H_(2)O(compound 3)(pz-pyrazine),were built from the linkage of[Co_(4)(H_(2)O)_(2)(P_(2)W_(15)O_(56)_(2)]^(16-)-(abbreviated as{Co_(4)P_(4)W_(30})polyanions and pz and/or cobalt(II)*** compounds 1 and 2 consisted of the same components,their lamellar networks were quite *** inorganic lamellar network in compound 3 was constructed by connecting{Co_(4)P_(4)W_(30)}units with cobalt(I)*** work demonstrates that the coordination modes of{Co_(4)P_(4)W_(30)}are very sensitive to synthesis conditions,while the ring-belt tetrametals are easily substituted by different transition metal cations under mild reaction conditions.

关键词： Cobalt Crystal structure Cyclic voltammetry Hybrid Polyoxometalate

Nonlinearly induced entanglement in dissipatively coupled optomechanical system

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Chinese Physics B 2024年第6期33卷 255-260页

作者：杨文全冷轩程泂张闻钊 department of Physics Ningbo UniversityNingbo 315211China

Nonlinearly induced steady-state photon–phonon entanglement of a dissipative coupled system is studied in the bistable regime. Quantum dynamical characteristics are analysed by solving the mean-field and fluctuation equations of the system. It is shown that dissipative coupling can induce bistable behaviour for the effective dissipation of the *** suitable parameters, one of the steady states significantly reduces the dissipative effect of the system. Consequently,a larger steady-state entanglement can be achieved compared to linear dynamics. Furthermore, the experimental feasibility of the parameters is analysed. Our results provide a new perspective for the implementation of steady-state optomechanical entanglement.

关键词： entanglement optomechanical system dissipatively coupling

The unitary subgroups of group algebras for a class of finite 2-groups with the derived subgroup of order 2

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Science China Mathematics 2024年第9期67卷 1989-2018页

作者： Yulei Wang Heguo Liu department of Mathematics Henan University of TechnologyZhengzhou 450001China department of Mathematics Hainan UniversityHaikou 570228China

Let p be a prime and F be a finite field of characteristic *** that FG is the group algebra of the finite p-group G over the field *** V(FG)denote the group of normalized units in FG and let V_(*)(FG)denote the unitary subgroup of V(FG).If p is odd,then the order of V_(*)(FG)is|F|^((|G-1)/2).However,the case p=2 still is *** this paper,the order of V*(FG)is computed when G is a nonabelian 2-group given by a central extension of the form 1→Z_(2^(n))×Z_(2^(m))→G→Z_(2)×…×Z_(2)→1 and G'≌Z_(2),n,m≥***,a conjecture is confirmed,i.e.,the order of V_(*)(FG)can be divisible by|F|^(1/2(|G|+|Ω1(G)|)-1),where Ω_(1)(G)={g∈G|g^(2)=1}.

关键词： normalized unit unitary subgroup inner abelian p-group central extension

Observational signatures of rotating black holes in the semiclassical gravity with trace anomaly

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Chinese Physics C 2024年第8期48卷 257-265页

作者： Zhenyu Zhang Yehui Hou Minyong Guo department of Physics Peking UniversityBeijing 100871China department of Physics Beijing Normal UniversityBeijing 100875China

In a recent work by Fernandes[***.D 108(6),L061502(2023)],an exact stationary and axisymmetric solution was discovered in semiclassical gravity with type-A trace *** was identified as a quantum-corrected version of the Kerr black *** this study,we explore the observational signatures of this black hole *** investigation reveals that prograde and retrograde light rings exist,whose radii increase monotonically with the coupling parameterα.Whenαis negative,the shadow area for the quantum-corrected black hole is smaller than that of the Kerr black hole,whereas whenαis positive,the area is *** a near-extremal black hole,its high-spin feature(the NHEKline)is found to be highly susceptible to disruption byα.Furthermore,we discuss the images of the quantum-corrected black hole in the presence of a thin accretion disk and compare them to those of the Kerr black *** study highlights the importance of near-horizon emission sources in detecting the effects of quantum corrections by black hole images.

关键词： quantum-corrected rotating black hole light rings black hole shadow

Molecular Dynamics Simulations of Displacement Cascade in Ni-Based Concentrated Solid Solution Alloys

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Acta Mechanica Solida Sinica 2024年第1期37卷 82-89页

作者： Chaoquan Zhao Rongxuan Xie Chuanlong Xu Xiaobao Tian Qingyuan Wang Wentao Jiang Haidong Fan department of Mechanics Sichuan UniversityChengdu 610065China

Single-phase concentrated solid solution alloys(SP-CSAs),including high-entropy alloys,have received extensive attention due to their excellent irradiation *** this work,displacement cascade simulations are conducted using the molecular dynamics method to study the evolution of defects in Ni-based *** with pure Ni,the NiCr,NiCo,and NiCu alloys exhibit a larger number of Frankel pairs(FPs)in the thermal peak stage,but a smaller number of surviving ***,the NiFe alloy displays the opposite *** explain these different observations for NiFe and other alloys,the formation energy and migration energy of interstitials/vacancies are *** the NiFe alloy,both the formation energy and migration energy barrier are *** the other hand,in NiCr and other alloys,the formation energy of interstitials/vacancies is lower,as is the migration energy barrier of *** energy analysis agrees well with previous *** present work provides new insights into the mechanism behind the irradiation resistance of binary Ni-based SP-CSAs.

关键词： Molecular dynamics simulation Displacement cascade Point defect Ni-based concentrated solid solution alloys

Modeling static friction behavior of elastic–plastic spherical adhesive microcontact in full-stick condition

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Friction 2024年第11期12卷 2594-2610页

作者： Guo XIANG Roman GOLTSBERG Izhak ETSION department of Mechanical Engineering TechnionHaifa 32000Israel

The static friction behavior of an elastic–plastic spherical adhesive microcontact between a rigid flat and a deformable sphere under combined normal and tangential loading is studied by the finite element method(FEM).The contact between the sphere and the rigid flat is assumed to be full-stick,and the sliding inception is related to a loss of tangential *** intermolecular force between the rigid flat and the sphere is assessed by the Lennard–Jones(LJ)potential,which is applied to the sphere and the rigid flat by a user *** evolution of the adhesive force with tangential displacement in the full-stick condition is *** results indicate that the increasing effect of adhesive energy on the static friction coefficient gradually diminishes with an increase in the adhesive energy and the external normal ***,based on an extensive parametric study,an empirical dimensionless expression is obtained to predict the static friction coefficient of the spherical adhesive microcontact considering the intermolecular force.

关键词： adhesive spherical microcontact Lennard–Jones(LJ)potential elastic–plastic static friction

High-resolution photogrammetry to measure physical aperture of two separated rock fracture surfaces

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2922-2934页

作者： Masoud Torkan Mateusz Janiszewski Lauri Uotinen Alireza Baghbanan Mikael Rinne department of Civil Engineering Aalto UniversityEspooFinland department of Mining Engineering Isfahan University of TechnologyIsfahanIran

Photogrammetry,reconstructing three-dimensional(3D)models from overlapping two-dimensional(2D)photos,finds application in rock mechanics and rock engineering to extract geometrical details of reconstructed objects,for example rock *** properties are important for determining the mechanical stability,permeability,strength,and shear behavior of the rock *** can be used to reconstruct detailed 3D models of two separated rock fracture surfaces to characterize fracture roughness and physical aperture,which controls the fluid flow,hydromechanical and shear behavior of the rock *** research aimed to determine the optimal number of scale bars required to produce high-precision 3D models of a fracture surface.A workflow has been developed to define the physical aperture of a fracture using *** blocks of Kuru granite(25 cm×25 cm×10 cm)with an artificially induced fracture,were *** scaling 3D models,321 markers were used as ground control points(GCPs)with predefined distances on each *** the samples were wellmatched in their original positions,the entire block was *** data of the GCPs were extracted from the 3D model of the *** half was surveyed separately and georeferenced by GCPs and merged into the same coordinate *** fracture surfaces were extracted from the 3D models and the vertical distance between the two surfaces was digitally calculated as physical *** assessment of the photogrammetric reconstruction showed a 20-30 mm digital control distance accuracy when compared to known distances defined between *** attain this accuracy,the study found that at least 200 scale bars were ***,photogrammetry was employed to measure changes in aperture under normal *** results obtained from this approach were found to be in good agreement with those obtained using linear variable displacement transducers(LVDTs),with differences ran

关键词： Photogrammetry Physical aperture Rock fracture Predefined distances Markers

Numerical analysis of moving train induced vibrations on tunnel,surrounding ground and structure

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 179-192页

作者： Swati Srivastav Sowmiya Chawla Swapnil Mishra department of Applied Geophysics Indian Institute of Technology(ISM)Dhanbad 826004India department of Civil Engineering Indian Institute of Technology(ISM)Dhanbad 826004India department of Mining Engineering Indian Institute of Technology(ISM)Dhanbad 826004India

This study is focused on the effect of vibration induced by moving trains in tunnels on the surrounding ground and structures.A three-dimensional finite element model is established for a one-track railway tunnel and an adjacent twelve-storey building frame by using commercial software Midas GTS-NX(2019)and Midas *** study considered the moving load effect of a complete train,which varies with space as well as with *** effect of factors such as train speed,overburden pressure on the tunnel and variation in soil properties are studied in the time *** a result,the variations in horizontal and vertical acceleration for two different sites,i.e.,the free ground surface(without structure)and the area containing the structure,are ***,the displacement pattern of the raft foundation is plotted for different train *** lower speeds,the heaving phenomenon is negligible,but as the speed increases,both the heaving and differential settlement increase in the *** study demonstrates that the effect of moving train vibrations should be considered in the design of new nearby structures and proper ground improvement should be considered for existing structures.

关键词： moving train load tunnels vibration effect finite element method(FEM) wave propagation

Assessment of the implementation status of best available techniques for cleaner production in the textile industry

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Frontiers of Environmental Science & Engineering 2024年第8期18卷 133-148页

作者： Mehmet Eren Yaman Emrah Ozturk Ulku Yetis Mehmet Kitis department of Environmental Engineering Suleyman Demirel UniversityIsparta 32260Turkey department of Environmental Protection Technologies Isparta University of Applied SciencesIsparta 32200Turkey department of Environmental Engineering Middle East Technical UniversityAnkara 06800Turkey

The draft Integrated Pollution Prevention and Control(IPPC)regulation mandates compliance with best available techniques(BATs)for textile manufacturers.A study in Turkish textile facilities,covering 56 units across four sub-sectors,assessed the status of 488 BATs through on-site visits and *** aim was to gauge the sector’s adherence to *** findings revealed that 37% of surveyed BATs were fully implemented,rising to 88% when considering potential future *** suggests a strong industry inclination toward adopting BATs for cleaner production and *** study highlighted significant BAT-related investments in the textile sector,driven by environmental concerns,regulations,customer demands,resource efficiency,competition,and cost-benefit ***,the study results also indicated that there is still much work to do for the implementation of some *** was found that 60 BATs had lower implementation ratios(IR:0%-43%).Lower IR values for these BATs are mainly due to factors like specificity,high costs,long payback periods,operational difficulties,limited expertise,space constraints,customer requirements,quality concerns,operational issues,and sector-specific *** study recommends similar assessments in other European industrial sectors to evaluate compliance with mandatory BATs outlined in the Industrial Emissions *** insights from this study on the Turkish textile sector can serve as a valuable guide for future evaluations.

关键词： Best available techniques(BAT) Cleaner production Green Deal Integrated Pollution Prevention and Control(IPPC) Textile sector