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Synthesis of coral-like structures of Pr-Yb co-doped YIG: Structural,optical, magnetic and antimicrobial properties

Journal of Rare Earths 2024年第3期42卷 543-554,I0004页

作者： A.Fernandez Francisca P.Araujo Y.Guerra S.Castro-Lopes J.Matilla-Arias Idglan S.de Lima Edson C.Silva-Filho Josy A.Osajima F.Guerrero R.Pena-Garcia Federal University of Piau Graduate Program in Materials Science and EngineeringTeresinaPIBrazil Federal Rural University of Pernambuco Academic Unit of Cabo de Santo AgostinhoCabo de Santo AgostinhoPEBrazil Federal University of Piaui Department of PhysicTeresinaPBrazil Federal University of Pernambuco Graduate Program in Materials ScienceRecifePEBrazil University of Granma Departmentof Basic Sciences and Applied InformaticsFaculty of Technical SciencesBayamoCuba Federal University of Amazonas Department of PhysicManausAMBrazil Federal University of Pernambuco Department of PhysicRecifePEBrazil

Coral-like structures of the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12),(0.00 ≤ x ≤ 0.04, 0.00 ≤ y ≤ 0.02) compound were synthesized using the sol-gel method. Structural investigation certified the YIG cubic crystal structure formation, without any secondary phase. It is shown that, the relatively large ionic radius of the dopant cations results in an expansion of the lattice parameter, variations in the Iona-O-Iondangle, Iona-O,Iond-O and Ionc-O bond distances and decrease in the average crystallite size. Fourier transform infrared(FTIR) and Raman measurements are essential to testify the single-phase formation of YIG crystal structure and are observed changes in the stretching and vibrational modes, respectively. The morphological study, energy dispersive spectroscopy(EDS) spectra and textural properties show corallike structures, peaks associated with Pr^(3+) and Yb^(3+) atoms and the effect of dopants on surface area,diameter, and pore volume, respectively. The optical analysis from diffuse reflectance spectra witnessed an increase in the optical gap band, a decrease in Urbach energy and blue shift in the charge transfer,correlated with the expansion of the unit cell due to the dopant's insertion in the YIG structure. A typical ferrimagnetic behavior is exhibited by the Y_(3-x)Pr_(x)Fe_(5-y)Yb_(y)O_(12)compound. The saturation magnetization(M_(s)), cubic anisotropy constant(K_(1)) and coercive field(H_(c)) increase with the Pr^(3+)cations content, as consequence of their magnetic nature and distribution around of Fe^(3+)ions due to the coexistence with the Yb^(3+). Finally, for the first time, antibacterial tests by mean of the direct contact method were performed for YIG co-doped with Pr^(3+)and Yb^(3+)and it is shown that, relatively high dosages of Pr^(3+) cations favored the activity against S. aureus, therefore, a new biological property for YIG doped with rare earths is presented.

关键词： Yttrium iron garnet(YIG) Coral-like structures Rare earths Band gap energy Magnetic properties Antimicrobial properties

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The Impact of Network Topologies and Radio Duty Cycle Mechanisms on the RPL Routing Protocol Power Consumption

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Computers, Materials & Continua 2024年第5期79卷 1835-1854页

作者： Amal Hkiri Hamzah Faraj Omar Ben Bahri Mouna Karmani Sami Alqurashi Mohsen Machhout physic department Electronics and Micro-Electronics LaboratoryFaculty of Sciences of MonastirMonastir5000Tunisia department of Science and Technology College of RanyahTaif UniversityP.O.Box 11099Taif21944Saudi Arabia

The Internet of Things(IoT)has witnessed a significant surge in adoption,particularly through the utilization of Wireless Sensor Networks(WSNs),which comprise small internet-connected *** deployments span various environments and offer a multitude of ***,the widespread use of battery-powered devices introduces challenges due to their limited hardware resources and communication *** response to this,the Internet Engineering Task Force(IETF)has developed the IPv6 Routing Protocol for Low-power and Lossy Networks(RPL)to address the unique requirements of such *** the critical role of RPL in maintaining high performance,this paper proposes a novel approach to optimizing power ***,it introduces a developed sensor motes topology integrated with a Radio Duty Cycling(RDC)mechanism aimed at minimizing power *** rigorous analysis,the paper evaluates the power efficiency of this approach through several simulations conducted across different network topologies,including random,linear,tree,and elliptical ***,three distinct RDC mechanisms—CXMAC,ContikiMAC,and NullRDC—are investigated to assess their impact on power *** findings of the study,based on a comprehensive and deep analysis of the simulated results,highlight the efficiency of ContikiMAC in power *** research contributes valuable insights into enhancing the energy efficiency of RPL-based IoT networks,ultimately facilitating their widespread deployment and usability in diverse environments.

关键词： WSN IoT radio duty cycles topologies

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RPL-Based IoT Networks under Decreased Rank Attack:Performance Analysis in Static and Mobile Environments

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Computers, Materials & Continua 2024年第1期78卷 227-247页

作者： Amal Hkiri Mouna Karmani Omar Ben Bahri Ahmed Mohammed Murayr Fawaz Hassan Alasmari Mohsen Machhout physic department Electronics and Micro-Electronics LaboratoryFaculty of Sciences of MonastirMonastir5000Tunisia department of Science and Technology College of RanyahTaif UniversityP.O.Box 11099Taif21944Saudi Arabia

The RPL(IPv6 Routing Protocol for Low-Power and Lossy Networks)protocol is essential for efficient communi-cation within the Internet of Things(IoT)*** its significance,RPL’s susceptibility to attacks remains a *** paper presents a comprehensive simulation-based analysis of the RPL protocol’s vulnerability to the decreased rank attack in both static andmobilenetwork *** employ the Random Direction Mobility Model(RDM)for mobile scenarios within the Cooja *** systematic evaluation focuses on critical performance metrics,including Packet Delivery Ratio(PDR),Average End to End Delay(AE2ED),throughput,Expected Transmission Count(ETX),and Average Power Consumption(APC).Our findings illuminate the disruptive impact of this attack on the routing hierarchy,resulting in decreased PDR and throughput,increased AE2ED,ETX,and *** results underscore the urgent need for robust security measures to protect RPL-based IoT ***,our study emphasizes the exacerbated impact of the attack in mobile scenarios,highlighting the evolving security requirements of IoT networks.

关键词： RPL decreased rank attacks mobility random direction model

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Seizure as the main presenting manifestation of three patients with acute glufosinate-ammonium poisoning

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2024年第4期25卷 354-358页

作者： Ping WANG Congying SONG Xuan LU Yuanqiang LU department of Emergency Medicine the First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 3100030 China Zhejiang Key Laboratory for Diagnosis and Treatment of physic chemical and Aging related Injuries Hangzhou 310003China department of Geriatric Medicine the First Affiliated HospitalSchool of MedicineZhejiang UniversityHangzhou 310003China

Glufosinate-ammonium herbicides are the most widely used broad-spectrum,non-selective herbicides in the ***-ammonium is a structural analogue of glutamate(Glu)which can irreversibly inhibit the activity of glutamine synthetase(GS)and Glu decarboxylase in plants,thereby blocking the synthesis of glutamine(Gln)from Glu and ammonia(Hoerlein,1994).This causes the plants to die because of the nitrogen metabolism disorder and subsequent intracellular accumulation of *** humans,the characteristic features of glufosinate-ammonium herbicide poisoning include gastrointestinal symptoms and neurotoxicity(Watanabe and Sano,1998).

关键词： ammonium ammonia thereby

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Severe liver injury and clinical characteristics of occupational exposure to 2-amino-5-chloro-N,3-dimethylbenzamide: A case series

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Hepatobiliary & Pancreatic Diseases International 2024年第2期23卷 186-194页

作者： Meng-Xiao Feng Hua Zou Yuan-Qiang Lu department of Emergency Medicine The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310003China Key Laboratory for Diagnosis and Treatment of Aging and physic-chemical Injury Diseases of Zhejiang Province Hangzhou 310003China Occupational Health and Radiation Protection Institute Zhejiang Provincial Center for Disease Control and PreventionHangzhou 310051China

Background:The 2-amino-5-chloro-N,3-dimethylbenzamide is a key intermediate in the synthesis of pesticides and ***,no literature currently exists on 2-amino-5-chloro-N,3-dimethylbenzamide poisoning in *** study aimed to reveal the health hazard of this chemical for humans and summarize the clinical characteristics of patients with occupational 2-amino-5-chloro-N,3-dimethylbenzamide ***:This observational study included four patients with 2-amino-5-chloro-N,3-dimethylbenzamide poisoning from June 2022 to July *** entire course of the incidents was described in *** 2-amino-5-chloro-N,3-dimethylbenzamide concentrations were detected by a mass ***-toxylin and eosin staining was performed to assess liver injury,and immunofluorescence was used to evaluate hepatic ***:The 2-amino-5-chloro-N,3-dimethylbenzamide powder(99%purity)entered the human body mainly via the skin and respiratory tract due to poor personal protective *** typical course of 2-amino-5-chloro-N,3-dimethylbenzamide poisoning was divided into latency,rash,fever,organic dam-age,and recovery phases in accordance with the clinical *** and fever may be the important premonitory symptoms for further organ *** chemical was detected in the blood of all patients and caused multiple organ injuries,predominantly liver injury,including kidney,myocardium,and *** patients recovered smoothly after comprehensive treatments,including artificial liver therapy,continuous renal replacement therapy,glucocorticoids,and other symptomatic and supportive *** patient survived by liver *** postoperative pathological findings of the removed liver showed acute liver failure,and immunofluorescence staining confirmed the abundance of mitophagy in residual ***:This study is the first to elaborate the clinical characteristics of patients with 2-amino-5-chloro-N,

关键词： 2-amino-5-chloro-N,3-dimethylbenzamide Poisoning Clinical characteristics Liver injury

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Refinement of the Proposed Gamma-Ray Burst Time Delay Model

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International Journal of Astronomy and Astrophysics 2024年第2期14卷 120-147页

作者： Godson Fortune Abbey Joseph Simfukwe Prospery Christopher Simpemba Saul Paul Phiri Alok Srivastava Golden Gadzirayi Nyambuya department of physic School of Mathematics and Natural Sciences The Copperbelt University Kitwe Republic of Zambia Fundamental Theoretical and Research Group Department of Applied Physics Faculty of Applied Sciences National University of Science & Technology Bulawayo Republic of Zimbabwe

This paper is the second instalment in our study of the observed time delay in the arrival times of radio photons emanating from Gamma Ray Bursts (GRBs). The mundane assumption in contemporary physics as to the cause of these pondersome time delays is that they are a result of the photon being endowed with a non-zero mass. While we do not rule out the possibility of a non-zero mass for the photon, our working assumption is that the major cause of these time delays may very well be that these photons are travelling in a rarefied cosmic plasma in which the medium’s electrons interact with the electric component of the Photon, thus generating tiny currents that lead to dispersion, hence, a frequency-dependent speed of Light (FDSL). In the present instalment, we “improve” on the model presented in the first instalment by dropping the assumption that the resultant pairs of these radio photons leave the shock front simultaneously. The new assumption of a non-simultaneous— albeit systematic—emission of these photon pairs allows us to obtain a much more convincing and stronger correlation in the time delay. This new correlation allows us to build a unified model for the four GRBs in our sample using a relative distance correction mechanism. The new unified model allows us to obtain as our most significant result a value for the frequency equivalence of the interstellar medium (ISM)’s conductance ν* ~ 1.500 ± 0.009 Hzand also an independent distance measure to the GRBs where we obtain for our four GRB samples an average distance of: ~69.40 ± 0.10, 40.00 ± 0.00, 58.40 ± 0.40, and 86.00 ± 1.00 Mpc, for GRB 030329, 980425, 000418 and 021004 respectively.

关键词： Gamma-Ray Bursts (GRB) Photon Mass Plasma Time Delay Fireball Model

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Seismicity patterns before the 2021 Fin (Iran) doublet earthquakes using the region-time-length and time-to-failure methods

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Earthquake Science 2024年第4期37卷 324-336页

作者： Salma Ommi Vladimir Borisovich Smirnov department of Environmental Planning and Design Environmental Science Research InstituteShahid Beheshti UniversityTehranIran department physic of The Earth Moscow State UniversityMoscowRussia Schmidt Institute of physics of the Earth Russian Academy of SciencesMoscowRussia

Knowledge regarding earthquake hazards and seismicity is crucial for crisis management, and the occurrence of foreshocks, seismic activity patterns, and spatiotemporal variations in seismic activity have been studied. Furthermore, the estimation of the region-time-length (RTL) parameter has been proposed to detect seismic quiescence before the occurrence of a large earthquake. In addition, the time-to-failure method has been used to estimate the time occurrence of large earthquakes. Hence, in this study, to gain deeper insight into seismic activity in the southern Zagros region, we utilized the RTL algorithm to identify the quiescence and activation phases leading to the Fin doublet earthquakes. Temporal variations in the RTL parameter showed two significant anomalies. One corresponded to the occurrence time of the first earthquake (2017-12-12);the other anomaly was associated with the occurrence time of the second event (2021-11-14). Based on a negative value of the RTL parameter observed in the vicinity of the Fin epicenters (2021), seismic quiescence (a decrease in seismicity compared to the preceding background rate) was identified. The spatial distribution of the RTL prognostic parameters confirms the appearance of seismic quiescence surrounding the epicenter of the Fin doublet earthquakes (2021). The time-to-failure method was designed using precursory events that describe the acceleration of the seismic energy release before the mainshock. Using the time-to-failure method for the earthquake catalog, it was possible to estimate both the magnitude and time of failure of the Fin doublet. Hence, the time-tofailure technique can be a useful supplementary method to the RTL algorithm for determining the characteristics of impending earthquakes.

关键词： earthquake catalog seismic quiescence region-time-length(RTL)algorithm time-to-failure method Fin doublet earthquakes.

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Numerical Assessment of the Thermal Efficiency of a Concentrated Photovoltaic/Thermal (CPV/T) Hybrid System Using Air as Heat Transfer Fluid

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Smart Grid and Renewable Energy 2024年第1期15卷 1-14页

作者： Amadou Konfe Boureima Kabore Yves Christian Nonguierma Fatimata Ouedraogo Sié Kam Laboratory of Thermal and Renewable Energies University Joseph Ki-Zerbo Ouagadougou Burkina Faso physic department University Norbert Zongo Koudougou Burkina Faso Photonics and Nolinear Optics Laboratory University of Moncton Moncton Canada

In this paper, we propose a thermal model of a hybrid photovoltaic/thermal concentration system. Starting from the thermal balance of the model, the equation is solved and simulated with a MATLAB code, considering air as the cooling fluid. This enabled us to evaluate some of the parameters influencing the electrical and thermal performance of this device. The results showed that the temperature, thermal efficiency and electrical efficiency delivered depend on the air mass flow rate. The electrical and thermal efficiencies for different values of air mass flow are encouraging, and demonstrate the benefits of cooling photovoltaic cells. The results show that thermal efficiency decreases air flow rate greater than 0.7 kg/s, whatever the value of the light concentration used. The thermal efficiency of the solar cell increases as the light concentration increases, whatever the air flow rate used. For a concentration equal to 30 sun, the thermal efficiency is 0.16 with an air flow rate equal to 0.005 kg/s;the thermal efficiency increases to 0.19 with an air flow rate equal to 0.1 kg/s at the same concentration. An interesting and useful finding was that the proposed numerical model allows the determination of the electrical as well as thermal efficiency of the hybrid CPV/T with air flow as cooling fluid.

关键词： PV Cell Concentrating Thermal Energy Conversion Cooling Hybrid System

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The impact of reabsorption effect on composition analysis of organic semiconductors

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Science China Materials 2024年第10期67卷 3124-3131页

作者： Bei Yang Xiaoke Liu Li Wan Weixin Ni Ni Yang Jianhui Hou Feng Gao Electronic and Photonic Materials(EFM) Department of PhysicsChemistry and Biology(IFM)Linkoping UniversityLinkoping SE-58183Sweden Beijing National Laboratory for Molecular Sciences State Key Laboratory of Polymer and ChemistryCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China Max Planck Institute of Microstructure physic Halle 06120Germany

Reabsorption is one of the most fundamental optical phenomena,but it has rarely been considered in spectroscopy-based composition analysis for organic ***,we take four state-of-the-art organic solar cell(OSC)materials as examples,and systematically investigate the influence of reabsorption on photoluminescence emission and excitation spectra by both experimental studies and optical *** find that the overlap between absorption and emission spectra of these OSC materials is strong enough for them to be affected by the reabsorption effect,and the effect becomes more obvious between different species in the multi-components ***,three features of the reabsorption effect and the reabsorption strength are identified,with which we have successfully analyzed the composition in a range of OSC materials in both solution and solid-state *** work not only provides an important understanding of the largely overlooked feature of reabsorption in the widely used spectroscopic techniques but also offers an effective toolbox for the composition analysis of organic semiconductors.

关键词： reabsorption effect composition analysis organic solar cells non-fullerene acceptors organic semiconductors

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Characterization of ZnO nanowire field-effect transistors exposed to ultraviolet radiation

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Chinese physics B 2009年第11期18卷 5020-5023页

作者：黎明张海英郭常新徐静波付晓君陈普锋 Institute of Microelectronics Chinese Academy of Sciences department of physic University of Science and Technology of China

A ZnO nanowire （NW） field-effect transistor （FET） is fabricated and characterized, and its characterization of ultraviolet radiation is also investigated. On the one hand, when the radiation time is 5 min, the radiation intensity increases to 5.1μW/cm^2, while the saturation drain current （Idss） of the nanowire FET decreases sharply from 560 to 320 nA. The field effect mobility（μ） of the ZnO nanowire FET drops from 50.17 to 23.82cm^2/（V·s） at VDS= 2.5V, and the channel resistivity of the FET increases by a factor of 2.0n the other hand, when the radiation intensity is 2.5μW/cm^2, the DC performance of the FET does not change significantly with irradiation time （its performances at irradiation times of 5 and 20 min are almost the same）; in particular, the Idss of NW FET only reduces by about 50 nA. Research is underway to reveal the intrinsic properties of suspended ZnO nanowires and to explore their device

关键词： ZnO nanowire suspended field-effect transistor ultraviolet radiation

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