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Near resonance vibration isolation on a levered-dual response(LEDAR)Coulomb-damped system by differential preloads/offsets in linear springs

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 1033-1050页

作者： t.i.tOLUWALOJU C.K.tHEiN D.HALiM Department of Mechanical Materials and Manufacturing EngineeringUniversity of Nottingham Ningbo ChinaNingbo 315100Zhejiang ProvinceChina Not.i.gham Ningbo China Beacons of Excellence Research and innovation institute University of Nottingham Ningbo ChinaNingbo 315048Zhejiang ProvinceChina

the levered-dual response(LEDAR)Coulomb-damped system att.i.s near resonant vibration isolation by differential preloads/offsets in linear *** takes the advantages of both the preloads/offsets in linear springs and the guiderail friction for realizing different levels of vibration *** isolation capacities are investigated on the strategies with both the horizontal and vertical guiderails,with the horizontal rail only,and without *** compressive preloads generally result.i. the consumption of most of the initial excitation energy so as to overcome the potential *** isolation onsets at the frequency ratio of 1∓0.095 on the left-hand side(LHS)and the right-hand side(RHS)of the lever are relative to the load plate *** observed near resonant.i.olation thus makes the LEDAR system a candidate for the isolation of the mechanical systems about resonance while opening a path for simultaneous harvesterisolation functions and passive functions at extreme frequencies.

关键词： lever ratio Coulomb damping preload tension/compression isolation band/depth offset potential

Design,simulation,and testing of a tunable MEMS multi-threshold inertial switch

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Microsystems & Nanoengineering 2024年第2期10卷 37-46页

作者： Qiu Xu Rodrigo t.Rocha Yousef Algoos Eric Feron Mohammad i.Younis Faculty of Electronic information Engineering Huaiyin Institute of TechnologyHuai’an223003PR China Computer Electrical and Mathematical Science and Engineering DivisionKing Abdullah University of Science and TechnologyThuwal23955-6900Saudi Arabia Piezoelect.i. Microsystem technologies Silicon Austria LabsVillach9524Austria Physical Sciences and Engineering Division King Abdullah University of Science and TechnologyThuwal23955Saudi Arabia Mechanical Engineering Department State University of New YorkBinghamtonNY13902USA

t.i. paper presents a tunable multi-threshold micro-electromechanical inertial switch with adjustable threshold *** demonstrated device combines the advantages of accelerometers in providing quantitative acceleration measurements and g-threshold switches in saving power when in the inactive state upon experiencing acceleration below the *** designed proof-of-concept device with two thresholds consists of a cantilever microbeam and two stationary electrodes placed at different positions in the sensing *** adjustable threshold capability and the effect of the shock duration on the threshold acceleration are analytically investigated using a nonlinear beam *** are shown for the relationships among the applied bias voltage,the duration of shock impact,and the tunable *** fabricated prototypes are tested using a shock-table *** analytical results agree with the experimental *** designed device concept.i. very promising for the classification of the shock and impact loads in transportation and healthcare applications.

关键词： tunable acceleration testing

Development of endemicity and conservation importance indices for tropical forests and the floral diversity assessment of *** in Benguet,Philippines

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Journal of Mount.i. Science 2024年第3期21卷 786-804页

作者： Johndale Rein t.BULLONG Jim P.SiLVERiO Joanna i.ALAFAG Maricel A.GURON Jones t.NAPALDEt Department of Environmental Science Benguet State UniversityLa Trinidad 2601Philippines Department of Biology Benguet State UniversityLa Trinidad 2601Philippines

the scientific community faces the challenge of measuring progress toward biodiversity targets and indices have been traditionally ***,recent.i.ventories in secondary tropical mount.i. forests using traditional biodiversity indices have yielded results that are indistinct with primary *** shows the need to develop complementary indices that goes beyond species count but.i.tegrates the dist.i.ution and conservation status of the *** study developed endemicity and conservation importance index for tropical forest that.i.corporated the dist.i.ution and conservation status of the *** indices were applied to ***,a remnant primary mossy forest.i. Buguias,Benguet,Philippines,that resulted to endemicity index of 81.07 and conservation importance index of *** these with secondary forest sites with comparable Shannon-Wiener,Simpson,Evenness and Margalef’s indices,our endemicity and conservation indices clearly differentiates primary forest(our study site)with higher values from secondary forests with much lower ***,we are proposing these indices for a direct but scientifically-informed identification of specific sites for conservation and protection in tropical ***,our study documented a total of 168 vascular plant species(79 endemic and 12 locally threatened species)in *** are of tropical elements for both generic and species levels with some temperate elements that could be att.i.uted to the site's high elevation and semi-temperate *** are important baseline information for conservation plans and monitoring of tropical mossy forests.

关键词： Endemicity index Conservation importance index Cordillera Central Range Floristic element Jaccard index of Similarity

Effectiveness of external prestressing in enhancing the non-ductile hanger failure mechanism in reinforced concrete inverted t-beams

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1050-1065页

作者： Ahmed M.AttA Reda N.BEHiRY Mohammed i.HARAZ Structural Engineering Department Faculty of EngineeringTanta UniversityTanta 33511Egypt Nile Higher institute for Engineering and technology Mansoura 11001Egypt

Recently,inverted t-beams have been used in reinforced concrete(RC)bridges to support transverse precast *** t-beams,contrary to practice with conventional beams,are loaded on the flanges upper *** loading configuration causes hanger failure due to the generation of vertical tensile stresses near the bottom of the *** key purpose of t.i. study is to investigate the efficiency of vertical external prestressing st.i.less-steel bars in mitigating non-ductile hanger failure in reinforced concrete inverted *** experimental study on six inverted-t beams,including two un-strengthened specimens,was carried *** study showed that the value of the prestressing level had a considerable impact on the performance of hanger mechanism in relation to crack pattern,ultimate loads,cracking behavior,load-deflection,strains,and *** experimental results indicated that the suggested method for strengthening inverted t-beams had efficacy in reducing the seriousness of the non-ductile hanger failure and resulted in a strength increase of up to 53% when compared to that of the un-strengthened ***,two analytical models for estimating the hanger capacity and the average crack width of the strengthened RC inverted t-beams were *** models that were proposed exhibited a high degree of agreement with the experimental results.

关键词： RC bridges inverted t-beams strengthening hanger failure external prestressing

Generalized time-dependent generator coordinate method for induced fission dynamics

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Frontiers of physics 2024年第4期19卷 1-12页

作者： B.Li D.Vretenar t.Nikšić J.Zhao P.W.Zhao J.Meng State Key Laboratory of Nuclear Physics and technology School of PhysicsPeking UniversityBeijing 100871China Physics Department Faculty of ScienceUniversity of Zagreb10000 ZagrebCroatia Center for Circuits and Systems Peng Cheng LaboratoryShenzhen 518055China

the generalized time-dependent generator coordinate method(tD-GCM)is extended to include pairing *** correlated GCM nuclear wave function is expressed in terms of time-dependent generator states and weight *** particle–hole channel of the effective interaction is determined by a Hamiltonian derived from an energy density functional,while pairing is treated dynamically in the standard BCS approximation with time-dependent pairing tensor and single-particle occupation *** the inclusion of pairing correlations,various time-dependent phenomena in open-shell nuclei can be described more *** model is applied to the description of saddle-to-scission dynamics of induced *** generalized tD-GCM charge yields and total kinetic energy dist.i.ution for the fission of 240Pu,are compared to those obt.i.ed using the standard time-dependent density functional theory(tD-DFt)approach,and with available data.

关键词： nuclear density functional theory generator coordinate method fission dynamics

ion heat transport.i. electron cyclotron resonance heated L-mode plasma on the t-10 tokamak

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Plasma Science and technology 2024年第4期26卷 52-60页

作者： V.A.KRUPiN M.R.NURGALiEV A.R.NEMEtS i.A.ZEMtSOV S.D.SUNtSOV t.B.MYALtON D.S.SERGEEV N.A.SOLOVEV D.V.SARYCHEV D.V.RYJAKOV S.N.tUGARiNOV N.N.NAUMENKO National Research Centre“Kurchatov institute” Moscow 123182Russia Bauman Moscow State technical University Moscow 105005Russia institution“Project Center itER” Moscow 123098Russia JSC“SOLAR” Minsk 220034Belarus

Anomalous ion heat transport.i. analyzed in the t-10 tokamak plasma heated with electron cyclotron resonance heating(ECRH) in second-harmonic extra-ordinary mode. Predictive modeling with empirical scaling for Ohmical heat conductivity shows that.i. ECRH plasmas the calculated ion temperature could be overestimated, so an increase of anomalous ion heat transport.i. required. to study t.i. effect two scans are presented: over the EC resonance position and over the ECRH power. the EC resonance position varies from the high-field side to the low-field side by variation of the toroidal magnetic field. the scan over the heating power is presented with on-axis and mixed ECRH regimes. Discharges with high anomalous ion heat transport are obt.i.ed in all considered regimes. in these discharges the power balance ion heat conductivity exceeds the neoclassical level by up to 10 times. the high ion heat transport regimes are distinguished by three parameters: the ratio te/ti, the normalized electron density gradient R/■, and the ion–ion collisionality νii~*. the combination of high te/ti, high νii~*, and R/■=6-10 results in values of normalized anomalous ion heat fluxes up to 10 times higher than in the low transport scenario.

关键词： tokamak L-mode electron cyclotron resonance heating ion heat transport

Energy exchange between charged relativistic fluids in f(t) gravity

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Communications in theoretical Physics 2024年第10期76卷 108-120页

作者： Z Yousaf U A Khokhar Nasser Bin turki t Suzuki Department of Mathematics University of the Punjab Quaid-i-Azam Campus Department of Mathematics College of Science King Saud University Department of Regional Management Faculty of Management Fukushima College

t.i. study focuses on the effects of a polytropic fluid on a charged gravitational source wit.i. f(t) gravity, where t.i. the torsion scalar. We investigate how the electromagnetic field affects the flow of energy in spherically symmet.i. and static celestial objects that cont.i. relativistic fluids. By using the gravitational decoupling technique, we analyze the effects of polytropic fluid on the dynamics of the gravitational source, accompanied by the matching of the interior geometry with an exterior at the hypersurface Σ. Finally, with the help of the tolman ⅡV solution, we observe the conduct of energy conditions with the existence of charge using f(t)field equations and got the intended outcomes.

关键词： anisotropy complexity energy exchange hydrodynamics self-gravitating systems

Porphyrins,phthalocyanines,and related covalent-organic frameworks in the photochemical and electrochemical water split.i.g:A review

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Particuology 2024年第7期90卷 236-265页

作者： Oxana V.Kharissova Yolanda Peña Méndez Boris i.Kharisov Aleksandr LNikolaev Edith Luévano-Hipólito Lucy t.González Universidad Autónoma de Nuevo León Ave.Universidad s/nSan Nicolás de los GarzaNuevo León66455Mexico Department of Chemistry Moscow State UniversityVorobievy HillsMoscowRussia CONACYt-Universidad Autónoma de Nuevo León Facultad de Ingeniería Civil-Departamento de Ecomateriales y EnergíaCd.UniversitariaC.P.66455San Nicolás de los GarzaNLMexico tecnologico de Monterrey Escuela de Ingeniería y CienciasMonterreyNuevo León 64890Mexico tecnologico de Monterrey Centro del AguaMonterreyNuevo León 64890Mexico

in t.i. review,the possibilities of photochemical and electrochemical water split.i.g(WS)using porphyrins,phthalocyanines,related macrocycles,and their metal complexes are *** efforts are being carried out.i. order to develop novel and cheap methods for water decomposition to generate inexhaustible greener energy sources(molecular hydrogen)instead of oil and *** processes of WS in heterogeneous and homogeneous media require novel photo-and electrocatalysts,in particular those on macrocycle basis.A high WS efficiency has been observed for porphyrins and phthalocyanines,showing their suitability both for HER and OER processes are available using these relative compounds for WS *** can be used in photocatalytic and electrocatalytic WS processes both in their free forms or as metal porphyrins/porphyrinates,mainly loaded on various inorganic materials,such as Au NPs,C_(3)N_(4),GaP,KtaO_(3),GaP,and so on,as part of porphyrin-cont.i.ing polymers or on electrode surface as modifying coatings,being sometimes better than commercial catalysts,such as Pt/*** H2 evolution can be considerably depended on the shape of porphyrin particles;in particular,porphyrin nanowires can yield up to 20 times more H2 than its *** cert.i. cases,both HER and OER can be driven in the same electrolyte using metal *** capacity of metal porphyrins to generate ROS(in particular,singlet oxygen 1O_(2))under ultrasonic treatment.i. known and can be successfully used for H_(2)O_(2) and O_(2) *** can be used in similar processes in free form or as composites with inorganic or organic counterparts,being immobilized on nanocarbons,metal oxides and salts,or simply dissolved in water acting in a homogeneous *** additional use of ultrasound can lead to better results due to the synergistic effect of the sonochemical treatment and ***-organic frameworks are also applied for WS purposes and are mainly based

关键词： Porphyrins Phthalocyanines COFs Water split.i.g Photocatalysis Electrocatalysis

Leading directions and effective distance of larch offspring dispersal at the upper treeline in the Northern and Polar Urals, Russia

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Forest Ecosystems 2024年第5期11卷 603-617页

作者： P.A.Moiseev V.L.Semerikov t.V.Semerikova D.S.Balakin i.B.Vorobiev S.O.Viuykhin institute of Plant and Animal Ecology Ural BranchRussian Academy of SciencesEkaterinburg620144Russia Center for Genetics and Life Science Sirius University of Science and Technology354340SochiRussia

Climate has changed sufficiently over the last 150 years and forced out upper treeline advance at the most studied sites around the *** rate of advance has been extremely variable–from tens to hundreds meters in *** is because the degree at which tree frontal populations respond to climate change depends on the complex interaction of biological and physical *** resulting stand pattern is the consequence of the interaction between dispersal and survival functions.A few publications have addressed the question of how t.i. pattern is *** order to understand how the spatial structure of tree stands was formed at the upper limit of their dist.i.ution in the Ural Mount.i.s,we assessed the distance and direction of dispersal of offspring from maternal *** found that.i. frontal Larix sibirica ***,‘effective’dispersal of offspring ranges from 3 to 758 m(with a median of 20–33 m in open forest and 219 m in single-tree tundra in the Polar Urals and 107 m in open forest.i. the Northern Urals).We revealed that most of the offspring effectively dispersed not only in the direction of the prevailing winds,but also in the opposite direction up the slope,and the distance can reach 500–760 *** data obt.i.ed can be used to develop an individual-based model which is capable of simulating in det.i. the dynamics of tree stands at the upper limit of their growth and reliably predicting the future position and pattern of treeline ecotone as growth conditions continue to improve in the face of observed climate change.

关键词： Effective dispersal distance Upper treeline Parentage analysis Age estimation terrest.i.l laser scanning Larix sibirica Ural mount.i.s