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Cool white light and tunable multicolor emission from Tb^(3+)/Dy^(3+)co-activated glasses under different excitations for WLEDs

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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

Compression properties of cost-efficient porous expanded clay reinforced AA7075 syntactic foams fabricated by industrial-oriented die casting technology

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China Foundry 2024年第1期21卷 60-70页

作者： İsmail Cem Akgün Çağın Bolat Ali Gökşenli Faculty of Mechanical Engineering Istanbul Technical University34437İstanbulTurkey Faculty of Engineering Samsun University55420SamsunTurkey

In today’s manufacturing industries,hard competition between rival firms makes it compulsory for researchers to design lighter and cheaper machine components due to the megatrends of cost-effectiveness and *** this point,aluminum syntactic foams(ASFs)are new-generation engineering composites and come into the upfront as a *** to their features like low density,sufficient elongation,and perfect energy absorption ability,these advanced foams have been considerably seductive for many industrial sectors *** this study,an industrial-oriented automatic die casting technology was used for the first time to manufacture the combination of AA7075/porous expanded clay(PEC).Micro evaluations(optical and FESEM)reveal that there is a homogenous particle distribution in the foam samples,and inspections are compatible with the other ASF ***,T6 aging heat treatment was operated on one half of the produced foams to explore the probable impact of aging on the compressive *** results show that PEC particles can be an alternative to expensive hollow spheres used in the previous ***,a favorable relationship is ascertained between the aging treatment and mechanical properties such as compression strength and plateau strength.

关键词： die casting porous materials metal matrix sytanctic foams expanded clay compressive deformation

Emission colour tuning in kLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)phosphor

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Journal of Rare Earths 2024年第1期42卷 57-65,I0002页

作者： Janani k Gayathri E Vijayatha V Ramasubramanian S Thiyagarajan P Department of Science and Humanities Nehru Institute of TechnologyKaliapuramThirumalayampalayamCoimbatoreIndia Department of Sciences Amrita School of Physical SciencesAmrita Vishwa VidyapeethamCoimbatoreIndia Department of Physics Anna UniversityChennaiIndia

kLnF_(4):Yb^(3+),Er^(3+)/Ho^(3+)(Ln=Y,Yb,Gd)phosphors were prepared by solid-state reaction *** each of the Yb^(3+)/Er^(3+)and Yb^(3+)/Ho^(3+)co-doped phosphors independently,phase confirmation and morphological examination were accomplished using the X-ray diffraction technique and scanning electron microscope analysis.X-ray photoelectron spectroscopy analysis shows the charge state and existence of lanthanides and *** luminescence emissions of green and red colour were detected for the synthesized *** changes in the upconverted emission intensities and colour output pertaining to the change of the lanthanide host matrix along with dopants were investigated for the prepared *** the upconversion luminescence,erbium-doped samples exhibit a predominance of red emission while holmium-doped samples display a prevalence of green *** rare-earth Er/Ho doped kYbF4shows strong red emission compared to other ***_(4):Yb,Er/Ho exhibits relatively significant green upconve rsion emissions,while Yb,Er-doped kGdF_(4)host displays a 10-fold increase in green/red emission ratio with an increase in the input power of 20-780 *** photoluminescence studies and decay curve analysis were carried out using UV light excitation for the developed phosphors.A higher lifetime of 2.2 ms was measured for the downshifting red emission in the Ho doped kYbF_(4)*** study suggests a potential for colour tunability in the upconversion and downshifting emissions through host modifications to the fluoride phosphor.

关键词： Rare earths Energy transfer upconversion Downshifting Colour coordinates

Towards sustainable agriculture:Harnessing AI for global food security

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Artificial Intelligence in Agriculture 2024年第2期12卷 72-84页

作者： Dhananjay k.Pandey Richa Mishra Amity Institute of Biotechnology Amity University JharkhandRanchi 835303India ICFAI University JharkhandRanchi 835222India

The issue of food security continues to be a prominent global concern,affecting a significant number of individ-uals who experience the adverse effects of hunger and *** finding of a solution of this intricate issue necessitates the implementation of novel and paradigm-shifting methodologies in agriculture and food *** recent times,the domain of artificial intelligence(AI)has emerged as a potent tool capable of instigating a profound influence on the agriculture and food *** technologies provide significant advantages by opti-mizing crop cultivation practices,enabling the use of predictive modelling and precision agriculture techniques,and aiding efficient crop monitoring and disease ***,AI has the potential to optimize sup-ply chain operations,storage management,transportation systems,and quality assurance *** also tackles the problem of food loss and waste through post-harvest loss reduction,predictive analytics,and smart inventory *** study highlights that how by utilizing the power of AI,we could transform the way we produce,distribute,and manage food,ultimately creating a more secure and sustainable future for all.

关键词： Global food security Artificial intelligence Crop improvement Food supply chain Sustainable resource management Food loss and waste

Exploring visual quality of multidimensional time series projections

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Visual Informatics 2024年第2期8卷 27-42页

作者： Tanja Munz-körner Daniel Weiskopf Visualization Research Center(VISUS) University of StuttgartAllmandring 19StuttgartGermany

Dimensionality reduction is often used to project time series data from multidimensional to two-dimensional space to generate visual representations of the temporal *** this context,we address the problem of multidimensional time series visualization by presenting a new method to show and handle projection errors introduced by dimensionality reduction techniques on multidimensional temporal *** visualization,subsequent time instances are rendered as dots that are connected by lines or curves to indicate the temporal ***,inevitable projection artifacts may lead to poor visualization quality and misinterpretation of the temporal *** projected data points,inaccurate variations in the distances between projected time instances,and intersections of connecting lines could lead to wrong assumptions about the original *** adapt local and global quality metrics to measure the visual quality along the projected time series,and we introduce a model to assess the projection error at intersecting *** serve as a basis for our new uncertainty visualization techniques that use different visual encodings and interactions to indicate,communicate,and work with the visualization uncertainty from projection errors and artifacts along the timeline of data points,their connections,and *** approach is agnostic to the projection method and works for linear and non-linear dimensionality reduction methods alike.

关键词： Time series Multidimensional data Dimensionality reduction Projection errors Visual quality Visual analytics

Optimised hybrid classification approach for rice leaf disease prediction with proposed texture features

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Journal of Control and Decision 2024年第1期11卷 84-97页

作者： Sakhamuri Sridevi k.kiran kumar Department of Computer Science and Engineering Koneru Lakshmaiah Education FoundationVaddeswaramIndia

This paper aims to frame a new rice disease prediction model that included three major ***,median filtering(MF)is deployed during pre-processing and then‘proposed Fuzzy Means Clustering(FCM)based segmentation’is *** that,‘Discrete Wavelet Transform(DWT),Scale-Invariant Feature Transform(SIFT)and low-level features(colour and shape),Proposed local Binary Pattern(LBP)based features’are extracted that are classified via‘MultiLayer Perceptron(MLP)and Long Short Term Memory(LSTM)’and predicted outcomes are *** exact prediction,this work intends to optimise the weights of LSTM using Inertia Weighted Salp Swarm Optimisation(IW-SSO)***,the development of IW-SSO method is established on varied metrics.

关键词： Rice disease improved fuzzy hybrid classifiers optimised LSTM IW-SSO algorithm

Excellent photoluminescence and electrochemical properties of Sm^(3+) doped Ca_(2)MgSi_(2)O_(7) nanophosphor:Display and electrochemical sensor applications

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Journal of Rare Earths 2024年第6期42卷 1046-1055,I0002页

作者： R.B.Basavaraj k.Sureshkumar D.P.Aarti M.B.Madhusudana Reddy G.Nagaraju T.Ramakrishnappa G.R.Navyashree k.R.Venkatesha Babu k.S.Hemalatha Department of Physics BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry BMS Institute of Technology and ManagementBangalore560064India Department of Chemistry School of Applied SciencesREVA UniversityBangalore560064India Energy Materials ResearchLaboratory Department of ChemistrySiddaganga Institute of TechnologyTumakuru57203KarnatakaIndia School of Physical Sciences REVA UniversityBangalore560057Indi Department of Physics Govt.Science CollegeBengaluru560001India Department of Physics Maharani Science College for WomenMaharani Cluster UniversityBengaluru560001India

A series of orange-red light emitting Ca_(2)MgSi_(2)O_(7):Sm^(3+)nanopowders were fabricated via low-cost ecofriendly green combustion technique using Aloe vera gel as *** phase purity of the samples were confirmed by the powder X-ray diffraction(PXRD)*** single-phase tetragonal structure is observed from the PXRD results with no additional impurity *** band gap energy of the fabricated powders was estimated by diffuse reflectance spectra(DRS)and is found to be in the range of 4.01-5.98 eV.A high resolution scanning electron microscope(SEM)was used to study the morphological behaviour of the ***-like structures are observed from the SEM *** particle size was evaluated by transmission electron microscopy(TEM)and is found to be~50 *** interplanar distance is found to be 0.53 *** properties were systematically studied in *** phosphors are successfully excited at 403 nm NUV light,producing reddish-orange characteristic *** emission peaks are centered at 558(^(4)G_(5/2)→^(6)H_(5/2)),607(^(4)G_(5/2)→^(6)H_(7/2))and 645 nm(^(4)G_(5/2)→^(6)H_(9/2)),*** the observed peaks the red emanation(^(4)G_(5/2)→^(6)H_(7/2))is stronger than the orange emission(^(4)G_(5/2)→^(6)H_(5/2))in the current *** photoluminescent concentration quenching is noticed above 5 mol%Sm^(3+)ion doping *** dipole-dipole interaction resulting in cross relaxation is found to be the principal cause of concentration quenching *** color features such as Commission Internationale de I’Eclairage(CIE)and correlated color temperature(CCT)were studied in *** optimized chromaticity coordinates were estimated to be(0.6363,0.3632),which fall in the reddish-orange *** average CCT value obtained is 3362 *** average color purity is found to be~82%.Sm^(3+)incorporated Ca_(2)MgSi_(2)O_(7) samples are possible contender for single white light generation commercial candidates owing to

关键词： Green combustion Photoluminescence Orange-red emission Color purity Sensors Rare earths

Covalent Bond Based Android Malware Detection Using Permission and System Call Pairs

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Computers, Materials & Continua 2024年第3期78卷 4283-4301页

作者： Rahul Gupta kapil Sharma R.k.Garg Department of Information Technology Delhi Technological UniversityNew Delhi110042India Department of Mechanical Engineering Deenbandhu Chhotu Ram University of Science and TechnologyMurthal131039India

The prevalence of smartphones is deeply embedded in modern society,impacting various aspects of our *** versatility and functionalities have fundamentally changed how we communicate,work,seek entertainment,and access *** the many smartphones available,those operating on the Android platform dominate,being the most widely used *** widespread adoption of the Android OS has significantly contributed to increased malware attacks targeting the Android ecosystem in recent ***,there is an urgent need to develop new methods for detecting Android *** literature contains numerous works related to Android malware *** far as our understanding extends,we are the first ones to identify dangerous combinations of permissions and system calls to uncover malicious behavior in Android *** introduce a novel methodology that pairs permissions and system calls to distinguish between benign and malicious *** approach combines the advantages of static and dynamic analysis,offering a more comprehensive understanding of an application’s *** establish covalent bonds between permissions and system calls to assess their combined *** introduce a novel technique to determine these pairs’Covalent Bond Strength *** pair is assigned two scores,one for malicious behavior and another for benign *** scores serve as the basis for classifying applications as benign or *** correlating permissions with system calls,the study enables a detailed examination of how an app utilizes its requested permissions,aiding in differentiating legitimate and potentially harmful *** comprehensive analysis provides a robust framework for Android malware detection,marking a significant contribution to the *** results of our experiments demonstrate a remarkable overall accuracy of 97.5%,surpassing various state-of-the-art detection techniques proposed in the current literature.

关键词： Android malware android security hybrid analysis permission and system call pairs

Dynamical system analysis of Dirac-Born-Infeld scalar field cosmology in coincident f(Q)gravity

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Chinese Physics C 2024年第9期48卷 199-209页

作者： Sayantan Ghosh Raja Solanki P.k.Sahoo Department of Mathematics Birla Institute of Technology and Science-PilaniHyderabad CampusHyderabad-500078India

In this article,we present a dynamical system analysis of a Dirac-Born-Infeld scalar field in a modified f(Q)gravity *** considered a polynomial form of modified gravity,used two different types of scalar potential,polynomial and exponential,and found a closed autonomous dynamical system of *** analyzed the fixed points of such a system and evaluated the conditions under which deceleration to late-time acceleration occurs in this *** note the similarity of the two models and show that our result is consistent with a previous study on Einstein s *** also investigated the phenomenological implications of our models by plotting EoS(ω),energy density(Ω),and deceleration parameter(q)*** e-fold time and comparing to the present *** conclude the paper by observing how the dynamical system analysis differs in the modified f(Q)gravity,and present the future scope of our research.

关键词： Dirac-Born-Infeld field f(Q)gravity dark energy dynamical system analysis