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Tensile deformation of fine-grained mg at 4K,78K and 298K

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Journal of magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： m.Walag A.Kula P.Noga T.Tokarski G.Cios m.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland materials Science and Engineering McMaster UniversityHamiltonCanada

The impact of grain size, ranging from 0.9 μm to 9 μm, on the mechanical properties of commercially pure mg is investigated at temperatures of 4K, 78K, and 298K. The mechanisms governing plastic flow are influenced by both grain size and temperature. At 4K and 78K, dominant deformation modes in mg involve dislocation glide and extension twinning, regardless of grain size. The interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime, leading to premature failure. The yield stress follows the Hall-Petch relationship σy~ k/√d, with the slope k increasing with decreasing temperature. At 298K, in addition to dislocation glide and twinning, grain boundary sliding(GBS) becomes significant in samples with grain sizes below 3 μm, considerably enhancing the material's deformability. GBS activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries, facilitating their absorption during sliding and rotation. Analysis of σ Θ relationship suggests that the basal slip is the dominant dislocation mode in mg at 298K. Decreasing grain size suppresses dislocation activity and twinning and increases GBS, resulting in lower Θ and σ Θ values. Suppressing conventional deformation modes coupled with enhanced GBS yields stress softening, breaking down the Hall-Petch relationship in mg below 3 μm grain size, leading to an inverse Hall-Petch behaviour. The work reports new data on the strength, ductility, work hardening and fracture behaviour, and their variations with mg grain size across different temperature regimes.

关键词： Polycrystalline mg mechanical properties Deformation mechanisms Work-hardening Texture evolution Cryogenic temperatures Hall-Petch relationship

Superior antibody and membrane protein‑specific T‑cell responses to CoronaVac by intradermal versus intramuscular routes in adolescents

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World Journal of Pediatrics 2024年第4期20卷 353-370页

作者： Jaime S.Rosa Duque Samuel m.S.Cheng Carolyn A.Cohen Daniel Leung Xiwei Wang Xiaofeng mu yuet Chung Tsun ming Lau manni Wang Wenyue Zhang yanmei Zhang Howard H.W.Wong Leo C.H.Tsang Sara Chaothai Tsz Chun Kwan John K.C.Li Karl C.K.Chan Leo L.H.Luk Jenson C.H.Ho Wing yan Li Amos m.T.Lee Jennifer H.y.Lam Sau man Chan Wilfred H.S.Wong Issan y.S.Tam masashi mori Sophie A.Valkenburg malik Peiris Wenwei Tu yu Lung Lau Department of Paediatrics and Adolescent medicine The University of Hong KongHong KongChina School of Public Health The University of Hong KongHong KongChina HKU‑Pasteur Research Pole School of Public HealthThe University of Hong KongHong KongChina Research Institute for Bioresources and Biotechnology Ishikawa Prefectural UniversityNonoichiJapan Department of microbiology and Immunology Peter Doherty Institute for Infectionand ImmunityUniversity of MelbourneMelbourneVICAustralia Center for Immunology and Infection C2i Hong KongChina

Background Optimising the immunogenicity of COVID-19 vaccines to improve their protection against disease is *** dosing by intradermal(ID)administration has been shown to be equally immunogenic as intramuscular(Im)administration for several vaccines,but the immunogenicity of ID inactivated whole severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)at the full dose is *** study(NCT04800133)investigated the superiority of antibody and T-cell responses of full-dose CoronaVac by ID over Im administration in *** Participants aged 11–17 years received two doses of Im or ID vaccine,followed by the 3rd dose 13–42 days *** and cellular immunogenicity outcomes were measured post-dose 2(Im-CC versus ID-CC)and post-dose 3(ImCCC versus ID-CCC).Doses 2 and 3 were administered to 173 and 104 adolescents,*** Spike protein(S)immunoglobulin G(IgG),S-receptor-binding domain(RBD)IgG,S IgG Fcγreceptor IIIa(FcγRIIIa)-binding,SNm[sum of individual(S),nucleocapsid protein(N),and membrane protein(m)peptide pool]-specific interleukin-2(IL-2)+CD4^(+),SNm-specific IL-2^(+)CD8^(+),S-specific IL-2^(+)CD8^(+),N-specific IL-2^(+)CD4^(+),N-specific IL-2^(+)CD8^(+)and m-specific IL-2^(+)CD4^(+)responses fulfilled the superior and non-inferior criteria for ID-CC compared to Im-CC,whereas IgG avidity was *** ID-CCC,S-RBD IgG,surrogate virus neutralisation test,90%plaque reduction neutralisation titre(PRNT90),PRNT50,S IgG avidity,S IgG FcγRIIIa-binding,m-specific IL-2^(+)CD4^(+),interferon-γ+CD8^(+)and IL-2^(+)CD8^(+)responses were superior and non-inferior to *** estimated vaccine efficacies were 49%,52%,66%and 79%for Im-CC,ID-CC,Im-CCC and ID-CCC,*** ID groups reported more local,mild adverse *** This is the first study to demonstrate superior antibody and m-specific T-cell responses by ID inactivated SARSCoV-2 vaccination and serves as the basis for future research to improve the

关键词： CoronaVac Coronavirus disease 2019 Immunity Intradermal Vaccine

Exploring the Prevalence and Contributing Factors of Depression among Sickle Cell Anemia Patients in Saudi Arabia’s Jazan Region

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International Journal of mental Health Promotion 2024年第5期26卷 351-359页

作者： Abdullah A.Alharbi Ahmad y.Alqassim mohammed A.muaddi Najat H.Aldubayyan Rana I.Abuhadi Futon A.Akoor Sarah J.mobarki Imtenan A.Oberi Ghaidaa H.Alharbi yara Ajeebi Adnan m.Alkhayat Hafiz malhan mohammed Bakkar Anwar m.makeen Family and Community medicine Department Faculty of MedicineJazan UniversityJazan45142Saudi Arabia Laboratory Department King Fahd Central HospitalMinistry of HealthJazan45142Saudi Arabia Internal medicine Department Prince Mohammad bin Nasser HospitalMinistry of HealthJazan45142Saudi Arabia Hematology Department King AbdulAziz Medical City for National GuardRiyadh11426Saudi Arabia

Sickle Cell Anemia(SCA)is a prevalent genetic condition in Saudi Arabia,particularly in the Jazan *** study’s purpose was to assess the prevalence of de-pression among individuals with SCA in this area and to identify the factors associated with this *** study involved 391 adult participants,all patients in the hematology center of Prince mohammed bin Nasser Hospital(PmNH).Data was collected through an anonymous interview questionnaire–the Arabic version of the Patient Health Questionnaire-9(PHQ-9)–between march–may *** questionnaire covered socio-demographic information and variables related to the participant’s SCA history,such as pain levels,frequency of pain,hospitalization duration,and frequency of blood *** variables underwent Chi-square and One-way ANOVA testing,followed by multivariate *** study found a 42%prevalence of depression among the SCA *** significantly linked with heightened depression levels included being widowed or divorced,experiencing frequent and severe pain,and longer duration of hospital *** educational level of at least a bachelor’s degree was also a significant *** study reveals a high prevalence of depression among SCA patients in the Jazan *** underscores the need for policymakers to educate both physicians and patients about the importance of mental health in SCA *** study also highlights the need for more research into the specific causes and effects of depressive symptoms in SCA patients to inform the creation of effective management plans.

关键词： Sickle cell anemia prevalence depression public health policy Jazan region Saudi Arabia

Sociodemographic Background and Psychosocial Behaviors of Perpetrators of Intimate Partner Violence: A Hospital-based Retrospective Study

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Journal of Forensic Science and medicine 2024年第3期10卷 176-183页

作者： Amal Nishantha Vadysinghe Tharanga Bandara Nayakarathne y.m.G.Ilangarathna Banda Kasun Bandara Ekanayake Isuru Perera yomal Wijesiriwardena Department of Forensic medicine Faculty of MedicineUniversity of PeradeniyaPeradeniyaSri Lanka Teaching Hospital Kurunegala KurunegalaSri Lanka

Background:Intimate partner violence(IPV)is a worldwide issue with a high prevalence rate seen *** and Objectives:To plan and implement preventive measures,it is important to understand the characteristics,background,and medico-legal significance,especially from the perspective of *** and methods:This study is a questionnaire-based retrospective study conducted among perpetrators of IPV who presented to a tertiary care hospital in Sri ***:Out of 325 subjects,97.2%were males and 64.0%were aged 26–45 ***(80.9%)perpetrators were older than the victimized partner,with a mean age gap of 4.3 *** 2.8%had achieved higher education and 78.5%had been married to the victim for more than5 *** and/or other substances were abused by 75.4%and 11.1%of them were diagnosed with a psychiatric *** have been exposed to child abuse(CA)as minors(50.1%),with physical CA being the most common,whereas 42.5%had witnessed IPV during their ***-treatment by the spouse(odds ratio[OR]=24[95%confidence interval(CI):5.6,99.9])and substance use(OR=22[95%CI:5.1,91.5])were significantly associated with perpetrating emotional violence.A victim having an extramarital affair was 5.1 times more likely to be subjected to sexual IPV,whereas previous IPV,parental deprivation,and affairs of perpetrator were proved to be protective *** had negatively affected the economy of 71.3%of *** procedures were expected by 22.4%,whereas 60%wanted to negotiate with their ***:Families having low income and alcohol/substance abuse should be targeted to plan preventive programs at the community *** counseling and follow-up of victims of CA can be used as a primary preventive measure of IPV.

关键词： Domestic violence intimate partner violence physical abuse sexual harassment

Europium recovery process by means of polymeric nanoparticles functionalized with acrylic acid,curcumin and fumaramide

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Journal of Rare Earths 2024年第10期42卷 1950-1959页

作者： P.A.martínez-montoya J.m.del Río A.de J.morales-Ramirez m.Corea Escuela Superior de Ingeniería Química e Industrias Extractivas ESIQIE-IPNDepartamento de Ingeniería Metalúrgica UPALM S/N Col.Lindavista Escuela Superior de Ingenieria Química e Industrias Extractivas ESIQIE-IPNLaboratorio de Investigación en Polímeros y NanomaterialesUPALM S/N Col.Lindavista Centra de Investigación e Innovación Tecnológica CIITEC-IPNCda.de CECATIs/n

Polymeric nanoparticles of poly(methyl methacrylate) were obtained by emulsion polymerization techniques in a proce ss of two *** particles were functionalized with acrylic acid,curcumin,and fumaramide and three series of polymeric particles were *** incorporation of functional groups was confirmed by Fourier transform-infrared spectrosocopy(FT-IR) and ultraviolet-visible(UV-Vis) *** spherical morphology of particles with an average diameter of 100 nm was observed by scartning electron microscopy(SEm).The polymeric materials were used for recovery of [Eu]from synthetic *** nanoparticles show excellent chelation capacity to trap rare-earth ions,because they recover more than 85% of [Eu] at pH of *** images of SEm after extraction process show arrays between particles with larger average particle sizes to 1.5 *** addition,the particles have a good stripping capacity,exceeding 50% of it,maintaining their homogeneity in morphology and good stability in dispersion for the recovery and stripping processes.A pseudo-second model order is obtained for the extraction and stripping processes while the best results of stripping process are obtained at pH of6.

关键词： Chelating effect Emulsion polymerization Extraction process Rare earths Stripping process [Eu]recovery

Investigation of the passive behaviour of AZ31B alloy in alkaline solutions

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Journal of magnesium and Alloys 2014年第2期2卷 175-180页

作者： A.fattah-alhosseini m.Sabaghi Joni Faculty of Engineering Bu-Ali Sina UniversityHamedan 65178-38695Iran

In this work,the passivity of AZ31B alloy in NaOH solutions was studied by potentiodynamic polarization,electrochemical impedance spectroscopy(EIS)and mott-Schottky *** polarization results indicated that decreasing NaOH concentration leads to decrease the corrosion rate of this *** results showed that the reciprocal capacitance(1/C)of the passive film is directly proportional to its thickness which increases with decreasing NaOH ***,it is clear that dilute NaOH solutions offer better conditions for forming the passive films with higher protection behaviour,due to the growth of a much thicker and less defective *** mott-Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics,where the oxygen vacancies and interstitials(over the cation vacancies)***,mott-Schottky results showed that the donor densities evaluated from mott-Schottky plots are in the range of 10^(20) cm^(−3) and decreased with decreasing NaOH concentration.

关键词： AZ31B alloy EIS mott-Schottky NaOH Passive film

Ab initio valence-space in-medium similarity renormalization group calculations for neutron-rich P,Cl,and K isotopes

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Chinese Physics C 2024年第7期48卷 181-190页

作者：谢萌冉沈留媛李健国李红蕙袁琪左维 Institute of modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear Science and Technology University of Chinese Academy of SciencesBeijing 100049China

Neutron-rich P,Cl,and K isotopes,particularly those with neutron numbers of approximately N=28,have attracted extensive experimental and theoretical *** utilize the ab initio valence-space in-medium similarity renormalization group approach,based on chiral nucleon-nucleon and three-nucleon forces,to investigate the exotic properties of these *** calculations of the low-lying spectra are performed.A key finding is the level inversion between 3/2_(1)^(+)and 1/2_(1)^(+)states in odd-A isotopes,attributed to the inversion ofπ0xod_(3/2) andπls_(1/2) single-particle *** ab initio calculations,which incorporate the three-nucleon forces,correlate closely with existing experimental *** calculations of effective proton single-particle energies provide deeper insights into the shell evolution for Z=14 and 16 *** results indicate that the three-body force plays important roles in the shell evolution for Z=14 and 16 sub-shells with neutron numbers ranging from 20 to ***,systematic ab initio calculations are conducted for the low-lying spectra of odd-odd *** results correspond with experimental data and provide new insights for future research into these isotopes up to and beyond the drip line.

关键词： ab initio calculations shell evolution low-lying spectra

Localization Dynamics at the Exceptional Point of Non-Hermitian Creutz Ladder

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Chinese Physics Letters 2024年第2期41卷 83-93页

作者：张舒迈何天毅金亮 School of Physics Nankai UniversityTianjin 300071China

We propose a quasi-one-dimensional non-Hermitian Creutz ladder with an entirely flat spectrum by introducing alternating gain and loss components while maintaining inversion *** interference generates a flat spectrum at the exceptional point,where the Creutz ladder maintains coalesced and degenerate eigenvalues with compact localized states distributed in a single *** excitations are completely confined within the localization area,unaffected by gain and ***-site excitations exhibit nonunitary dynamics with intensities increasing due to level coalescence,while multiple-site excitations may display oscillating or constant intensities at the exceptional *** results provide insights into the fascinating dynamics of non-Hermitian localization,where level coalescence and degeneracy coexist at the exceptional point.

关键词： exceptional excitation oscillating

Kinematic analysis of flexible bipedal robotic systems

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Applied mathematics and mechanics(English Edition) 2024年第5期45卷 795-818页

作者： R.FAZEL A.m.SHAFEI S.R.NEKOO Department of mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de Sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous *** distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases ***,the human leg bones that are involved in walking are supported by viscoelastic muscles and ***,for achieving more exact results,it is essential to model the robot links with viscoelastic *** this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of *** most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational *** extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned *** overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient