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Journal of Rare Earths 2024年第1期42卷 46-56,I0002页

作者： L.Vijayalakshmi k.Naveen kumar Jong dae Baek department of Automotive Engineering Yeungnam UniversityGyeongsanGyeongbuk38541Republic of Korea department of Mechanical Engineering Yeungnam UniversityGyeongsan38541Republic of Korea

A set of co-doped(Tb^(3+)/dy^(3+))lithium zinc borate(LZB)glasses were developed by melt *** structural evaluation was performed for synthesized glassy *** dy^(3+)and Tb^(3+)individually doped glasses exhibit intense yellow and green luminescence bands at 575 nm(^(4)F_(9/2)→^(6)H_(13/2))and543 nm(^(5)d_(4)→^(7)F_(5)),*** sensitization effect of dy^(3+)on Tb^(3+)was analyzed by increasing the Tb^(3+)content with respect to the optimum dy^(3+)content(0.5 mol%)in dy^(3+)/Tb^(3+).The spectral overlay of dy^(3+)luminescence and Tb^(3+)absorption profiles,dy^(3+)/Tb^(3+)PL spectra under different excitations 352,362,376,and 385 nm,shortening decay lifetimes of dy^(3+)in dy^(3+)/Tb^(3+)co-activated glasses,energy transfer(ET)parameters,chromaticity coordinates and their corresponding correlated temperatures all help to explain ET from dy^(3+)to Tb^(3+).At 385 nm of dy^(3+)excitation,the optimized co-activated(0.5dy^(3+)+1.0Tb^(3+)):LZB glass displays cool white light *** non-radiative ET from dy^(3+)to Tb^(3+)is dominated by electric dipole-dipole interaction and its ET efficiency was calculated to be 63%.At the same time,reverse ET from Tb^(3+)to dy^(3+)was also *** shift in color coordinates from dominant yellow to greenish-yellow,green and white light emission suggests that dy^(3+)/Tb^(3+)coactivated LZB glasses can be a potential candidate for UV converted multicolor and white light emitting devices.

关键词： Rare earths Photoluminescence Energy transfer Spectral overlap decay lifetime Multicolor emitting LEds

Highly Efficient Back‑End‑of‑Line Compatible Flexible Si‑Based Optical Memristive Crossbar Array for Edge Neuromorphic Physiological Signal Processing and Bionic Machine Vision

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Nano-Micro Letters 2024年第11期16卷 323-339页

作者： dayanand kumar Hanrui Li dhananjay d.kumbhar Manoj kumar Rajbhar Uttam kumar das Abdul Momin Syed Georgian Melinte Nazek El‑Atab Smart Advanced Memory Devices and Applications(SAMA)LaboratoryElectrical and Computer EngineeringComputer Electrical Mathematical Science and EngineeringKing Abdullah University of Science and Technology(KAUST)23955‑6900 ThuwalSaudi Arabia

The emergence of the Internet-of-Things is anticipated to create a vast market for what are known as smart edge devices,opening numerous opportunities across countless domains,including personalized healthcare and advanced *** 3d integration,edge devices can achieve unprecedented miniaturization while simultaneously boosting processing power and minimizing energy ***,we demonstrate a back-end-of-line compatible optoelectronic synapse with a transfer learning method on health care applications,including electroencephalogram(EEG)-based seizure prediction,electromyography(EMG)-based gesture recognition,and electrocardiogram(ECG)-based arrhythmia *** experiments on three biomedical datasets,we observe the classification accuracy improvement for the pretrained model with 2.93%on EEG,4.90%on ECG,and 7.92%on EMG,*** optical programming property of the device enables an ultralow power(2.8×10^(-13) J)fine-tuning process and offers solutions for patient-specific issues in edge computing ***,the device exhibits impressive light-sensitive characteristics that enable a range of light-triggered synaptic functions,making it promising for neuromorphic vision *** display the benefits of these intricate synaptic properties,a 5×5 optoelectronic synapse array is developed,effectively simulating human visual perception and memory *** proposed flexible optoelectronic synapse holds immense potential for advancing the fields of neuromorphic physiological signal processing and artificial visual systems in wearable applications.

关键词： Neuromorphic computing Electrophysiological signal Artificial vision system Image recognition Memristor

Crystal structure and luminescence dynamics of highly pure LiM(PO_(3))_(3):Eu^(3+)(M=Sr,Ca) red phosphors for white light emitting diodes

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Journal of Rare Earths 2024年第8期42卷 1470-1478,I0002页

作者： Payal khajuria M.Manhas A.k.Bedyal Ankush Vij H.C.Swart Vinay kumar department of Physics and Astronomical Sciences Central University of JammuRahy-Suchani.Samba1143J&KIndia department of Physics School of SciencesCluster University of JammuCanal RoadJammu180001India department of Physics University of Petroleum and Energy StudiesDehradunUttarakhand248007India department of Physics University of the Free StateP.O.Box 339BloemfonteinZA 9300South Africa

Highly pure red phosphors LiM(PO_(3))_(3):Eu^(3+)(M=Sr,Ca) doped with Eu^(3+)(1 mol%) were synthesized via solution combustion method and their crystal structure and luminescence dynamics were studied to explore its suitability in white light emitting *** Rietveld refinement analysis of the powder Xray diffraction patterns reveals that the phosphors belong to the pure triclinic phase of LiSr(PO_(3))_(3) and LiCa(PO_(3)) with space group P-1(2).The scanning electron microscopy images showed the agglomerated *** photoluminescence emission spectra under 393 nm show an orange band at 594 nm and a red band at 613 nm ascribed to ^(5)d_(0)→^(7)F_(1).^(5)d_(0)→^(7)F_(2) transitions of Eu^(3+)ion in both the ***,the spectroscopic properties such as luminescence behaviour,and Stark splitting were used to examine the symmetry of Eu^(3+)ions in LiM(PO_(3))_(3):Es^(3+)(M=Sr,Ca) phosphors in terms of distortion induced upon *** Stark splitting shows that the actual site symmetry for Eu^(3+)ion was estimated to be d_(2) type for both *** photometric properties of LiCa(PO_(3))_(3):Eu^(3+)such as Commission International de l'Eclairage coordinates(x=0.64,y=0.36) near to the standard one(red),high color purity(95%) and higher brightness reveal that the phosphor has the capability of acting as a red component in n-UV white light emitting diodes.

关键词： Photoluminescence Phosphate WLEds Stark splitting Rare earths

Thermodynamic properties and phase diagram of quark matter within non-extensive Polyakov chiral SU(3)quark mean field model

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Chinese Physics C 2024年第5期48卷 60-71页

作者： dhananjay Singh Arvind kumar department of Physics Dr.B R Ambedkar National Institute of Technology JalandharJalandhar–144008PunjabIndia

In the present study,we applied Tsallis non-extensive statistics to investigate the thermodynamic properties and phase diagram of quark matter in the Polyakov chiral SU(3)quark mean field *** this model,the properties of the quark matter were modified through the scalar fieldsσ,ζ,δ,χ,vector fieldsω,ρ,ϕ,and Polyakov fieldsΦandΦ¯at finite temperature and chemical ***-extensive effects were introduced through a dimensionless parameter q,and the results were compared to those of the extensive case(q→1).In the non-extensive case,the exponential in the Fermi-dirac(Fd)function was modified to a q-exponential *** influence of the q parameter on the thermodynamic properties,pressure,energy,and entropy density,as well as trace anomaly,was *** speed of sound and specific heat with non-extensive effects were also ***,the effect of non-extensivity on the deconfinement phase transition as well as the chiral phase transition of u,d,and s quarks was *** found that the critical end point(CEP),which defines the point in the(T−μ)phase diagram where the order of the phase transition changes,shifts to a lower value of temperature,TCEP,and a higher value of chemical potential,μCEP,as the non-extensivity is increased,that is,q>1.

关键词： quark matter quark mean field model QCd phase diagram non-extensive statistics

Constructing a biofunctionalized 3d-printed gelatin/sodium alginate/chitosan tri-polymer complex scaffold with improvised biological andmechanical properties for bone-tissue engineering

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Bio-design and Manufacturing 2024年第1期7卷 57-73页

作者： Amit kumar Singh krishna Pramanik Amit Biswas Centre of Excellence in Tissue Engineering Department of Biotechnology and Medical EngineeringNational Institute of TechnologyRourkela 769008India

Sodium alginate(SA)/chitosan(CH)polyelectrolyte scaffold is a suitable substrate for tissue-engineering *** present study deals with further improvement in the tensile strength and biological properties of this type of scaffold to make it a potential template for bone-tissue *** experimented with adding 0%–15%(volume fraction)gelatin(GE),a protein-based biopolymer known to promote cell adhesion,proliferation,and *** resulting tri-polymer complex was used as bioink to fabricate SA/CH/GEmatrices by three-dimensional(3d)*** studies using scanning electron microscopy revealed the microfibrous porous architecture of all the structures,which had a pore size range of 383–419μm.X-ray diffraction and Fourier-transform infrared spectroscopy analyses revealed the amorphous nature of the scaffold and the strong electrostatic interactions among the functional groups of the polymers,thereby forming polyelectrolyte complexes which were found to improve mechanical properties and structural *** scaffolds exhibited a desirable degradation rate,controlled swelling,and hydrophilic characteristics which are favorable for bone-tissue *** tensile strength improved from(386±15)to(693±15)kPa due to the increased stiffness of SA/CH scaffolds upon addition of *** enhanced protein adsorption and in vitro bioactivity(forming an apatite layer)confirmed the ability of the SA/CH/GE scaffold to offer higher cellular adhesion and a bone-like environment to cells during the process of tissue *** vitro biological evaluation including the MTT assay,confocal microscopy analysis,and alizarin red S assay showed a significant increase in cell attachment,cell viability,and cell proliferation,which further improved biomineralization over the scaffold *** addition,SA/CH containing 15%gelatin designated as SA/CH/GE15 showed superior performance to the other fabricated 3d structures,demonstrating its pote

关键词： Scaffold Biomaterial Sodium alginate Chitosan Gelatin 3d printing Tissue engineering

Aerodynamics of a Tandem-Bladed Axial Compressor Rotor under Circumferential distortion at different Rotational Speeds

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Journal of Thermal Science 2024年第4期33卷 1340-1356页

作者： Amit kumar Jerry T.JOHN A.M.PRAdEEP R.A.dAkkERMANS dragan kOZULOVIC department of Aerospace Engineering Indian Institute of Technology BombayMumbai400076India department of Automotive and Aeronautical Engineering Hamburg University of Applied Sciences20099HamburgGermany Institute of Jet Propulsion Bundeswehr University Munich85577NeubibergGermany

For most aircraft engines,inflow distortion is *** distortion is known to degrade the aerodynamic performance and stable operating limits of a *** rotor configuration is an arrangement that effectively controls the growth of the boundary layer over the suction surface of the ***,a higher total pressure rise can be achieved through this unconventional design approach involving the splitting of the blade into forward and aft *** is expected that the effect of inlet flow distortion would be more severe for a tandem-rotor design due to the greater flow turning inherent in such ***,this aspect needs to be thoroughly *** present study discusses the effect of circumferential distortion on the tandem-rotor at different rotational ***-annulus RANS simulations using ANSYS CFX are used in the present *** performance of the rotor at a particular flow coefficient and different rotational speeds is *** total pressure and efficiency are observed to drop at lower mass flow rates under the influence of circumferential *** loss region in each blade passage is mainly associated with the blade wake,tip leakage vortex,secondary flow,and boundary ***,their contribution varies from passage to passage,particularly in the distorted *** the lower span,the wake width is found to be higher than that at a higher *** to the redistribution of the mass flow,the circumferential extent reduces at a higher *** the undistorted sector,the strength of the tip leakage vortex is significantly higher at the design rotational speed than at lower *** distortion near the tip region promotes an early vortex breakdown even at the design operating *** adversely affects the total pressure,efficiency,and stall *** clean flow conditions,this phenomenon is only observed near the stall *** the design operating condition,the breakdown of the forward rotor tip l

关键词： tandem rotor circumferential distortion loss tip leakage vortex vortex breakdown diffusion factor aerodynamics of compressor blade

Intrusion detection Model Using Chaotic MAP for Network Coding Enabled Mobile Small Cells

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Computers, Materials & Continua 2024年第3期78卷 3151-3176页

作者： Chanumolu kiran kumar Nandhakumar Ramachandran School of Computer Science and Engineering VIT-AP UniversityAmaravatiAndhra Pradesh522241India

Wireless Network security management is difficult because of the ever-increasing number of wireless network malfunctions,vulnerabilities,and *** security systems,such as Intrusion detection Systems(IdS),are essential due to the limitations of simpler security measures,such as cryptography and *** to their compact nature and low energy reserves,wireless networks present a significant challenge for security *** features of small cells can cause threats to the *** Coding(NC)enabled small cells are vulnerable to various types of *** attacks and performing secure“peer”to“peer”data transmission is a challenging task in small *** to the low power and memory requirements of the proposed model,it is well suited to use with constrained small *** attacker cannot change the contents of data and generate a new Hashed Homomorphic Message Authentication Code(HHMAC)hash between transmissions since the HMAC function is generated using the shared *** this research,a chaotic sequence mapping based low overhead 1d Improved Logistic Map is used to secure“peer”to“peer”data transmission model using lightweight H-MAC(1d-LM-P2P-LHHMAC)is proposed with accurate intrusion *** proposed model is evaluated with the traditional models by considering various evaluation metrics like Vector Set Generation Accuracy Levels,key Pair Generation Time Levels,Chaotic Map Accuracy Levels,Intrusion detection Accuracy Levels,and the results represent that the proposed model performance in chaotic map accuracy level is 98%and intrusion detection is 98.2%.The proposed model is compared with the traditional models and the results represent that the proposed model secure data transmission levels are high.

关键词： Network coding small cells data transmission intrusion detection model hashed message authentication code chaotic sequence mapping secure transmission

MXenes: Versatile 2d materials with tailored surface chemistry and diverse applications

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Journal of Energy Chemistry 2024年第3期90卷 253-293,I0008页

作者： Sunil kumar Nitu kumari Yongho Seo department of Nanotechnology and Advanced Materials Engineering and HMC Sejong UniversitySeoul 05006South Korea School of Studies in Chemistry Jiwaji UniversityGwalior 474011India

MXenes,the most recent addition to the 2d material family,have attracted significant attention owing to their distinctive characteristics,including high surface area,conductivity,surface characteristics,mechanical strength,*** review begins by presenting MXenes,providing insights into their structural characteristics,synthesis methods,and surface functional *** review covers a thorough analysis of MXene surface properties,including surface chemistry and termination group *** properties of MXenes are influenced by their synthesis,which can be fluorine-based or ***-based synthesis techniques involve etching with fluorine-based reagents,mainly including HF or LiF/HCl,while fluorine-free methods include electrochemical etching,chemical vapor deposition(CVd),alkaline etching,Lewis acid-based etching,*** techniques result in the emergence of functional groups such as-F,-O,-OH,-Cl,*** the MXenes surface,depending on the synthesis method *** of MXenes,such as electrical conductivity,electronic properties,catalytic activity,magnetic properties,mechanical strength,and chemical and thermal stability,are examined,and the role of functional groups in determining these properties is *** review delves into the diverse applications of MXenes,encompassing supercapacitors,battery materials,hydrogen storage,fuel cells,electromagnetic interference(EMI) shielding,pollutant removal,water purification,flexible electronics,sensors,additive manufacturing,catalysis,biomedical and healthcare fields,***,this article outlines the challenges and opportunities in the current and future development of MXenes research,addressing various aspects such as synthesis scalability,etching challenges,and multifunctionality,and exploring novel *** review concludes with future prospects and conclusions envisioning the impact of MXenes on future technologies and innovation.

关键词： MXenes 2d materials Surface chemistry MXenes structure Synthesis Applications

Negative Stiffness Mechanism on An Asymmetric Wave Energy Converter by Using A Weakly Nonlinear Potential Model

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China Ocean Engineering 2024年第4期38卷 689-700页

作者： Sunny kumar POGULURI dongeun kIM Yoon Hyeok BAE department of Ocean Engineering IIT MadrasChennaiIndia Multidisciplinary Graduate School Program for Wind Energy Jeju National UniversityJejuRepublic of Korea Mechanical and System design Engineering Hongik UniversitySeoulRepublic of Korea

Salter's duck,an asymmetrical wave energy converter(WEC)device,showed high efficiency in extracting energy from 2d regular waves in the past;yet,challenges remain for fluctuating wave *** can potentially be addressed by adopting a negative stiffness mechanism(NSM)in WEC devices to enhance system efficiency,even in highly nonlinear and steep 3d waves.A weakly nonlinear model was developed which incorporated a nonlinear restoring moment and NSM into the linear formulations and was applied to an asymmetric WEC using a time domain potential flow *** model was initially validated by comparing it with published experimental and numerical computational fluid dynamics *** current results were in good agreement with the published *** was found that the energy extraction increased in the range of 6%to 17%during the evaluation of the effectiveness of the NSM in regular *** irregular wave conditions,specifically at the design wave conditions for the selected test site,the energy extraction increased by 2.4%,with annual energy production increments of approximately *** findings highlight the potential of NSM in enhancing the performance of asymmetric WEC devices,indicating more efficient energy extraction under various wave conditions.

关键词： asymmetric wave energy converter negative stiffness mechanism weakly nonlinear potential flow power