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Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(english edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-TALOOKOLAeI H.gHANDVAR e.JUMAeV S.KHATIR T.CUONg-Le School of Mechanical engineering Babol Noshirvani University of Technology Department of Mechanical engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for engineering Application and Technology Solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FgP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

关键词： Kinetic energy

Advancement in utilization of magnetic resonance imaging and biomarkers in the understanding of schizophrenia

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World Journal of Clinical Cases 2025年第1期13卷 11-15页

作者： Aidan K Tirpack Danyaal g Buttar Mandeep Kaur Department of Psychiatry Campbell University School of Osteopathic MedicineBuies CreekNC 27506United States Department of Psychiatry and Behavioral Health Mercyhealth Hospital and Trauma CenterJanesvilleWI 53548United States

Historically,psychiatric diagnoses have been made based on patient’s reported symptoms applying the criteria from diagnostic and statistical manual of mental *** utilization of neuroimaging or biomarkers to make the diagnosis and manage psychiatric disorders remains a distant *** have been several studies that examine brain imaging in psychiatric disorders,but more work is needed to elucidate the complexities of the human *** this editorial,we examine two articles by Xu et al and Stoyanov et al,that show developments in the direction of using neuroimaging to examine the brains of people with schizo-phrenia and *** et al used magnetic resonance imaging to examine the brain structure of patients with schizophrenia,in addition to examining neurotransmitter levels as *** et al used functional magnetic resonance imaging to look at modulation of different neural circuits by diagnostic-specific scales in patients with schizophrenia and *** two studies provide crucial evidence in advancing our understanding of the brain in prevalent psychiatric disorders.

关键词： Schizophrenia Magnetic resonance imaging Biomarkers Neurotransmitters Psychiatric disorders

Dipole (hyper)polarizabilities of neutral silver clusters

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Chinese Physics B 2016年第12期25卷 217-222页

作者： Francisco e Jorge Luiz g M de Macedo Departarnento de Fisica Universidade Fedoral do Espirito Santo 29060-900 Vitoria Brazil Unidade Academica de Fisica Universidade Federal de Campina Grande 58429-900 Campina Grande Brazil Faculdade de Biotecnologia ICB Universidade Federal do Para 66075-110 Belem Brazil

At the Douglas-Kroll-Hess （DKI4） level, the B3PW91 functional along with the all-eleclron relativistic basis sets of valence triple and quadruple zeta qualities are used to determine the structure, stability, and electronic properties of the small silver clusters （Agn, n ≤ 7）. The results presented in this study are in good agreement with the experimental data and theoretical values obtained at a higher level of theory from the literature. Static polarizability and hyperpolarizability are also reported. It is verified that the mean dipole polarizability per atom exhibits an odd-even oscillation and that the polarizability anisotropy is directly related to the cluster shape. In this article, the first study of hyperpolarizabilities of small silver clusters is presented. except for the monomer, the second hyperpolarizabilities of the silver clusters are significantly larger than those of the copper clusters.

关键词： B3PW91 functional all-electron basis sets non-relativistic and DKH2 calculations silver clusters,dipole (hyper)polarizabilities

The Binary Black Hole Scenario for the BL Lacertae Object AO 0235+16

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Chinese Journal of Astronomy and Astrophysics 2003年第6期3卷 513-525页

作者： g.e.Romero Jun-HuiFan S.e.Nuza InstitutoArgentinodeRadioastrononia C.C.5（1894）VillaElisaBs.As.Argentina CenterforAstrophysics GuangzhouUniversityGuangzhou510400 DepartamentodeFisicaJ.J.giambiagi FCENUBAPabellon1CiudadUniversitaria1428BuenosAiresArgentina

Recent analysis of the long term radio light curve of the extremely variableBL Lacertae object AO 0235+16 by Raiteri et al. have revealed the presence of recurrent outburstswith a period of ～ 5.7 +- 0.5 yr. Periodicity analysis of the optical light curve also showsevidence for a shorter period. Here we discuss whether such a behavior can be explained by a binaryblack hole model where the accretion disk of one of the supermassive black holes is precessing dueto the tidal effects of the companion. We estimate the mass of the accreting hole and analyzeconstraints on the secondary mass and the orbital parameters of the system. It is possible toprovide a viable interpretation of the available multiwavelength data.

关键词： galaxies: active BL lacertae objects: individual: AO 0235+16 -gamma rays:theory black hole physics

A non-fluorinated mechanochemically robust volumetric superhydrophobic nanocomposite

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Journal of Materials Science & Technology 2021年第7期66卷 213-225页

作者： e.Vazirinasab g.Momen R.Jafari Department of Applied Sciences University of Quebec in Chicoutimi(UQAC)555boul.de I'universiteChicoutimiQuebecG7H 2B1Canada

The widespread use of water-repellent superhydrophobic surfaces is limited by the inherent fragility of their micro-and nanoscale roughness, which is prone to damage and degradation. Here, we report a non-fluorinated volumetric superhydrophobic nanocomposites that demonstrate mechanochemical robustness. The nanocomposites are produced through the addition of microscale diatomaceous earth and nanoscale fumed silica particles to high-temperature vulcanized silicone rubber. The water-repellency of the surface and bulk of nanocomposites having 120 phr of filler was determined based on the water contact angle and contact angle hysteresis. We compared the water-repellency of nanocomposites of differing diatomaceous earth to fumed silica mass ratios. Increasing the amount of diatomaceous earth enhanced the water-repellency of the nanocomposite surface, whereas an increased amount of fumed silica improved the water-repellency of the bulk material. Moreover, increasing the diatomaceous earth/fumed silica mass ratio improved the cross-linking density and hardness values of the *** being subjected to a range of mechanical durability tests, including sandpaper abrasion,knife scratching, tape peeling, water jet impact, and sandblasting, the nanocomposite maintained a water contact angle of 163. and contact angle hysteresis of 2°. When the water-repellency of the prepared nanocomposites eventually deteriorated, we restored their superhydrophobicity by removing the upper surface of the nanocomposite. This extraordinary robustness stems from the embedded low surface energy micro/nanostructures distributed throughout the nanocomposite. We also demonstrated the chemical stability, UV resistance, and self-cleaning abilities of the nanocomposite to illustrate the potential for real-life applications of this material.

关键词： Volumetric superhydrophobic Nanocomposite Diatomaceous earth Hierarchical micro/nanostructure Mechanical robustness Chemical stability Self-cleaning

Association of Adolescent Bullying Victimization with Meeting 24-hour Movement Behavior Recommendations:A Cross-Sectional Study Using the Combined 2015-2019 Youth Risk Behavior Survey

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Journal of Science in Sport and exercise 2023年第2期5卷 182-190页

作者： You Fu Ryan DBurns Peng Zhang Samantha dyer Nora Constantino School of Public Health University of NevadaRenoNVUSA Department of Health&Kinesiology University of UtahSalt Lake CityUTUSA Physical education Teacher education Department East Stroudsburg UniversityEast StroudsburgPAUSA

Purpose To examine the association between bullying victimization and meeting recommendations for the 24-h movement behaviors of physical activity,screen use,and sleep in *** Participants were a sample of US adolescents from the 2015–2019 national Youth Risk Behavior Survey(N=43,847;Mean age=16.0±1.2 years;50.7%female).The bullying victimization variables included the bullying expe-riences at school and *** multivariable logistic regressions analyzed associations between bullying victimiza-tion and meeting recommendations for 24-h movement behaviors controlling for age,sex,race/ethnicity,and weight *** Adolescents meeting non-academic screen and sleep recommendations had 25%(OR=0.75,95%CI 0.69–0.82)and 19%(OR=0.81,95%CI 0.74–0.89)lower odds to be bullied at *** meeting non-academic screen recommen-dation had 27%lower odds(OR=0.73,95%CI 0.58–0.91)of experience online *** adolescents who met physical activity,non-academic screen use,and sleep recommendations had lower odds of experience the bullying at school of 29%(OR=0.71,95%CI 0.59–0.85),26%(OR=0.74,95%CI 0.61–0.90),and 31%(OR=0.69,95%CI 0.55–0.86),*** the females,non-academic screen use was the only movement behavior yielded statistical significance,in that those who met the recommendation had 15%(OR=0.85,95%CI 0.73–0.98)lower odds of experience the bullying at *** The presence of meeting 24-h movement behavior recommendations associates with a lower probability of bullying at school and online in ***,these associations tended to be stronger and more consistent in males compared to females.

关键词： School bullying Cyber bullying Youth Behavior

A Model to Describe the Fracture of Porous Polygranular graphite Subject to Neutron Damage and Radiolytic Oxidation

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Computers, Materials & Continua 2016年第3期51卷 163-185页

作者： g.Smith e.Schlangen P.e.J.Flewitt A.g.Crocker A.Hodgkins Interface Analysis Centre School of PhysicsUniversity of BristolBristolBS81TLUK Faculty of Civil engineering and geosciences Delft University of TechnologyDelftNetherlands HH Wills Physics Laboratory School of PhysicsUniversity of BristolBristolBS81TLUK Physics Department University of SurreyGuildfordGU27XH AMeC Clean energy now AMEC Foster-WheelerWalton House404 Faraday StreetBirchwood ParkWarringtonCheshireWA36GAUK

Two linked models have been developed to explore the relationship between the amount of porosity arising in service from both radiolytic oxidation and fast neutron damage that influences both the strength and the force-displacement(load-displacement)behaviour and crack propagation in pile grade A graphite used as a nuclear reactor moderator *** models of the microstructure of the porous graphite for both unirradiated and irradiated graphite are *** form the input for the second stage,simulating fracture in lattice-type finite element models,which predicts force(load)-displacement and crack propagation *** comprising aligned filler particles,typical of needle coke,in a porous matrix have been *** purpose was to isolate the contributions of filler particles and porosity to fracture strength and crack paths and consider their implications for the overall failure of reactor core graphite.

关键词： Reactor core graphite Modelling microstructure Fe lattice model Fracture strength Crack path

Soil Temperature Dependent growth of Cotton Seedlings Before emergence

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Pedosphere 2008年第1期18卷 54-59页

作者： g.NABI C.e.MULLINS Land Resources Research Program National Agricultural Research CentrePark RoadIslamabad45500 (Pakistan) Department of Plant and Soil Science Cruickshank BuildingUniversity of AberdeenAB24 3UU (UK)

Soil temperature is an important variable governing plant growth and development. Studies were conducted under laboratory conditions to determine the effect of soil temperature on root and shoot growth of cotton during emergence. Cotton seedlings were grown for 192 h at 20, 32 and 38℃ in soil packed in 300 mm long and 50 mm diameter cylinders. The data indicated that the longest roots （173 ram） as well as shoots （152 mm） were recorded at 32℃ followed by 20 （130 mm root and 82 mm shoot） and 38℃ （86 mm root and 50 mm shoot）. Roots grown at 20 and 38 ℃ were 20% and 50% shorter, respectively, than those grown at 32℃ after 192 h. Roots and shoots exhibited the lowest length and dry biomass at 38 ℃. Shoot lengths grown at 20 （74 mm） and 38℃（51 mm） were 44% and 61% shorter than those grown at 32℃（131 mm） after 180 h growth period, respectively. growth at all three temperatures followed a similar pattern. Initially there was a linear growth phase followed by the reduction or cessation of growth. Time to cessation of growth varied with temperature and decreased faster at higher temperatures. Sowing of cotton should be accomplished before seedbed reaches a soil temperature （≥ 38 ℃） detrimental for emergence. Further, the seedbeds should be capable of providing sufficient moisture and essential nutrients for emerging seedling before its seed reserves are exhausted to enhance seedling establishment in soil.

关键词： linear growth root/shoot elongation soil temperature

Modular next generation fast-neutron detector for portal monitoring

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Nuclear Science and Techniques 2022年第1期33卷 140-148页

作者： e.Aboud S.Ahn g.V.Rogachev V.e.Johnson J.Bishop g.Christian e.Koshchiy C.e.Parker D.P.Scriven Cyclotron Institute Texas A&M UniversityCollege StationTX 77843USA Department of Physics and Astronomy Texas A&M UniversityCollege StationTX 77843USA Department of Statistics Texas A&M UniversityCollege StationTX 77843USA

Nuclear nonproliferation is of critical importance for global *** fissile materials including highly enriched uranium and weapons-grade plutonium are especially important to *** interrogation techniques may result in much better sensitivity but are difficult with conventional portal monitors that rely on detecting thermal ***,most conventional portal monitoring systems rely on ^(3)He,which has a finite and continually decreasing *** designing a highly segmented array of organic scintillators,we posit that we can accurately and quickly identify fissile materials,including weapons-grade plutonium and highly enriched uranium,being *** propose a new design for a fast-neutron detector that overcomes the limitations of the current generation of portal ***6 simulations have been performed in conjunction with the UMPBT statistical model to determine the sensitivity limitations of the proposed *** suggest that the proposed detector may be 10 times more efficient than current-generation thermal neutron detectors and may be able to positively identify a 81 mg 235U source in as little as 192 seconds utilizing active interrogation techniques.

关键词： Fast-neutron detection Portal monitoring Nonproliferation