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Early Phases of Star Formation: Testing chemical Tools

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Research in Astronomy and Astrophysics 2024年第1期24卷 96-118页

作者： n.c.Martinez S.Paron cOnIcET-Universidad de Buenos Aires.Instituto de Astronomía y Física del Espacio Ciudad Universitaria(C1428EGA)Ciudad Autónoma de Buenos AiresArgentina

Star-forming processes strongly influence the ISM ***,many high-quality databases are available at millimeter *** them,it is possible to carry out studies that review and deepen previous *** these studies involve large samples of sources,it is preferred to use direct tools to study the molecular *** the aim of testing these tools such as the use of the Hcn/Hnc ratio as a thermometer,and the use of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H as "chemical clocks," we present a molecular line study toward 55 sources representing massive young stellar objects at different evolutionary stages:infrared dark clouds(IRDcs),highmass protostellar objects(HMPOs),hot molecular cores(HMcs) and ultracompact H II *** found that the use of the Hcn/Hnc ratio as a universal thermometer in the ISM should be taken with care because the Hcn optical depth is a big issue that can affect the ***,this tool should be utilized only after a careful analysis of the Hcn spectrum,checking that no line,neither the main nor the hyperfine ones,presents absorption *** point out that the analysis of the emission of H^(13)cO^(+),Hc_(3)n,n_(2)H^(+) and c_(2)H could be useful to trace and distinguish regions among IRDcs,HMPOs and *** molecular line widths of these four species increase from the IRDc to the HMc stage,which can be a consequence of the gas dynamics related to the starforming processes taking place in the molecular *** results not only contribute with more statistics,acting as a probe of such chemical tools,useful to obtain information in large samples of sources,but also complement previous works through the analysis of other types of sources.

关键词： stars:formation ISM:molecules ISM:clouds

Imprints of a gravitational wave through the weak field deflection of photons

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chinese Physics c 2024年第8期48卷 240-245页

作者： Reggie c.Pantig Ali Övgün Physics Department Mapúa University658 Muralla St.IntramurosManila 1002Philippines Physics Department Eastern Mediterranean UniversityFamagusta99628 North Cyprusvia Mersin 10Turkiye

In this study,we investigate the novel phenomenon of gravitational lensing experienced by gravitational waves traveling past a Schwarzschild black hole perturbed by a specific,first-order,polar gravitational *** apply the Gauss-Bonnet theorem,finding a topological contribution to the deflection of light rays passing near the black *** demonstrate that the deflection angle can be determined by analyzing a region entirely outside the path of the light ray,leading to a calculation based solely on the parameters of the perturbing wave(Legendre polynomial order,l;frequency,σ).This approach offers a unique perspective on gravitational lensing and expands our understanding of black hole interactions with gravitational waves.

关键词： supermassive black holes gravitational waves chaos weak deflection angle Gauss-Bonnet theorem

Single atom cu-n-c catalysts for the electro-reduction of cO_(2) to cO assessed by rotating ring-disc electrode

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Journal of Energy chemistry 2024年第1期88卷 169-182,I0004页

作者： S.Pérez-Rodríguez M.Gutiérrez-Roa c.Giménez-Rubio D.Ríos-Ruiz P.Arévalo-cid M.V.Martínez-Huerta A.Zitolo M.J.Lázaro D.Sebastián Instituto de carboquímica(cSIc) Miguel Luesma Castán 450018 ZaragozaSpain Instituto de catálisis y Petroleoquímica(cSIc) Marie Curie 228049 MadridSpain Synchrotron SOLEIL L’Orme des MerisiersDépartementale 12891190France

The electrochemical cO_(2) reduction reaction(cO_(2)RR) to controllable chemicals is considered as a promising pathway to store intermittent renewable energy. Herein, a set of catalysts based on copper-nitrogendoped carbon xerogel(cu-n-c) are successfully developed varying the copper amount and the nature of the copper precursor, for the efficient cO_(2)RR. The electrocatalytic performance of cu-n-c materials is assessed by a rotating ring-disc electrode(RRDE), technique still rarely explored for cO_(2)RR. For comparison, products are also characterized by online gas chromatography in a H-cell. The as-synthesized cu-nc catalysts are found to be active and highly cO selective at low overpotentials(from -0.6 to -0.8 V ***) in 0.1 M KHcO_(3), while H_(2) from the competitive water reduction appears at larger overpotentials(-0.9 V vs. RHE). The optimum copper acetate-derived catalyst containing cu-n_(4) moieties exhibits a cO_(2)-to-cO turnover frequency of 997 h^(-1) at -0.9 V vs. RHE with a H_(2)/cO ratio of 1.8. These results demonstrate that RRDE configuration can be used as a feasible approach for identifying electrolysis products from cO_(2)RR.

关键词： cu-n-c carbon xerogel Rotating ring disc electrode carbon dioxide reduction reaction carbon monoxide

Mathematical modeling and simulations of stress mitigation by coating polycrystalline particles in lithium-ion batteries

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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： n.IQBAL J.cHOI S.F.SHAH c.LEE S.LEE Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline ni-rich LinixMnyco_(z)O_(2)(x≥0.8)(nMc)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary nMc particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of nMc active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation ni-rich LinixMnyco_(z)O_(2)(x>0.8)(nMc)

Empirical model for fusion cross sections of ca-induced reactions

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chinese Physics c 2024年第3期48卷 126-132页

作者： Reddi Rani.L n.Sowmya K.n Sridhar H c.Manjunatha M.M.Armstrong Arasu Department of Physics St.Joseph's College(Autonomous)Affiliated to Bharathidasan UniversityTiruchirappalli620002TNIndia Department of Physics Govt.First.Grade CollegeChikkaballapur-562101KarnatakaIndia Department of Physics Govt.First.Grade CollegeMalur-563160KarnatakaIndia Department of Physics Govt.First.Grade CollegeDevanahalli-562110KarnatakaIndia

A new empirical formula for the astrophysical S-factor has been suggested as a function of the coulomb interaction parameter,center of mass energy,and barrier *** 22 fusion reactions with ^(40,48)ca as projectiles were considered for different targets,leading to compound nuclei with atomic and mass numbers varying between 40≤Z≤≤Z≤112 and 88≤A≤27888≤A≤278,*** fusion cross-sections have been estimated using the geometric factor,the Gamow-Sommerfield factor,and the empirical formula for the *** study's findings showed better agreement with those of available experiments when compared to Wong's *** present work leads to a smaller standard deviation value than Wong's formula when used to correlate the experimental data of calcium-induced fusion ***'s formula provides a good approximation of fusion cross-sections when the center of mass energy is below the fusion barrier when compared to above the fusion barrier.

关键词： fusion cross-sections Wong formula Gamow-Sommerfield-factor Geometric-factor S-factor

Polio eradication surveillance in Sri Lanka,2019-2023

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Asian Pacific Journal of Tropical Medicine 2024年第6期17卷 268-272页

作者： M.A.Y.Fernando n.S.Madarasinghe c.Rangana n.Weerasinghe D.c.U.D.Weligamage J.I.Abeynayake Department of Medical Microbiology and Immunology Faculty of MedicineUniversity of ColomboSri Lanka Department of Virology Medical Research InstituteColombo 08Sri Lanka Medical Research Institute Colombo 08Sri Lanka

Objective:To evaluate the polio laboratory surveillance carried out from January,2019 to May,2023 by the Polio Regional Reference Laboratory,Sri ***:This retrospective study analyzed all stool samples received under the acute flaccid paralysis(AFP)and immunodeficient vaccine-derived poliovirus(VDPV)surveillance at Polio Regional Reference Laboratory,Sri Lanka from January,2019 to May,*** results of the testing methodologies were extracted from the laboratory data system,i.e.,poliovirus virus isolation,intra-typic differentiation/VDPV real time reverse transcriptase polymerase chain reaction(ITD/VDPV rRTPcR)and sequencing,along with the data on timing of reporting results,stool adequacy and *** was analyzed using descriptive ***:A total of 2141 stool samples from 1644 cases were received for AFP surveillance from Sri Lanka(93.61%),Maldives(1.52%),and immunodeficient VDPV(4.86%)*** polioviruses(19/1644,1.15%)and non-polio enteroviruses(73/1644,4.44%)were isolated,while Sabin-like 3 virus was detected in majority(12/19,63.15%)among the poliovirus *** polioviruses or circulating VDPVs were not detected among the *** all years of the study,the non-polio AFP detection rate was>1/100000 in children aged less than 15 years,whereas stool adequacy rate was>80%.All results were reported within 14 days of receipt,ensuring timely reporting as per global ***:The Polio Regional Reference Laboratory,Sri Lanka plays a vital role in maintaining the polio-free status in the country through its robust laboratory surveillance,while adhering to the surveillance ***-detection of wild polioviruses and circulating VDPV during the study period reinforces the polio-free status in the country.

关键词： Poliovirus Polio laboratory surveillance Regional reference laboratory Polio eradication

Automating selective area electron diffraction phase identification using machine learning

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Journal of Materiomics 2024年第4期10卷 896-905页

作者： M.Mika n.Tomczak c.Finney J.carter A.Aitkaliyeva nuclear Engineering Program in Department of Materials Science University of Florida100 Rhines HallGainesville32611FLUSA Department of Materials Science&Engineering Case Western Reserve University2111 Martin Luther King Jr DrCleveland44106OHUSA

Selective area electron diffraction(SAED)patterns can provide valuable insight into the structure of a ***,the manual identification of collected patterns can be a significant bottleneck in the overall phase classification *** this work,we utilize the recent advances in computer vision and machine learning(ML)to automate the indexing of SAED *** performance of six different ML algorithms is demonstrated using metallic plutonium-zirconium *** most successful approach trained a neural network(nn)to make a classification of the phase and zone axis,and then utilized a second nn to synthesize multiple independent predictions of different tilts in a single sample to make an overall phase *** results demonstrate that automated SAED phase identification using ML is a viable route to accelerate materials characterization.

关键词： Selective area electron diffraction Machine learning Phase identification Metallic fuels Pu alloys

Airway management of a patient with linear immunoglobulin A bullous dermatosis:A case report

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World Journal of clinical cases 2024年第13期12卷 2263-2268页

作者： Olga c nin Robert Hutnik neil n chheda David Hutchinson Department of Anesthesiology University of Florida College of MedicineGainesvilleFL 32610United States Department of Otolaryngology University of Florida College of MedicineGainesvilleFL 32610United States

BAcKGROUnD There is limited literature on managing the airway of patients with linear immunoglobulin A(IgA)bullous dermatosis,a rare mucocutaneous disorder that leads to the development of friable *** clinical decision making is necessary when there is a risk of bleeding into the airway,and a multidisciplinary team approach may lead to decreased patient morbidity during these high-risk scenarios,especially when confronted with an unusual cause for *** SUMMARY A 45-year-old African American female presented to our ambulatory surgical center for right corneal transplantation due to corneal perforation after blunt trauma in the setting of cicatricial conjunctivitis and diffuse corneal neovascularization from linear IgA bullous *** diagnosis of IgA dermatosis was recent,and the patient had been lost to *** severity of the disease and extent of airway involvement was unknown at the time of the *** airway bleeding was noticed upon intubation and the otorhinolaryngology team had to be called to the operating *** patient required transfer to the intensive care unit where a multidisciplinary team was involved in her *** patient was extubated on postoperative day *** A multidisciplinary approach to treating this disease is the best course of action before a surgical *** our case,key communication between the surgery,anesthesia,and dermatology teams led to the quick and safe treatment of our patient’s *** surgery should not be considered for these cases unless they are in full remission and there is no mucous membrane involvement.

关键词： Airway management Bleeding risk Linear immunoglobulin A bullous dermatosis Multidisciplinary approach Outpatient procedure case report

Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.W.Huang K.Jiang c.n.Wu H.Peng P.c.hen R.Li H.B.Zhuo c.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been widely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,we propose and demonstrate that periodic thin slits can be regarded as a new breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction with thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse with periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared with conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense