检索结果-南通市图书馆

Facile synthesis of samarium an. cerium doped double perovskite cobaltite with enhan.ed dielectric response

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas m.Kamran.m.an.s-ur-Rehman Applied Thermal Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of Sm-Ce doping on structure,conduction,an. dielectric response of Bi_(2)Ca_(2-2x)Sm_(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specimens were synthesized by a facile synthesis technique named the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice parameters,lattice strain,unit cell volume,an. bulk density were determined using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were examined using calculations based on the density functional *** an. experimental values discrepan.y is less than.1%.A scan.ing electron microscope was used for performing a microstructural *** SEm images demonstrate the homogeneous distribution of grains with a ran.e of sizes(0.054-0.090μm).The alternating current(ac)conductivity,dielectric permittivity,an. tan.ent loss were also studied as a function of frequency(20 Hz-3 mHz)at different temperatures(100-500℃).All synthesized samples were examined using non-linear Debye's function to determine their spreading factor an. relaxation *** specimen with the lowest crystallite size(∼23 nm)exhibits a high dielectric permittivity(∼3.80×10^(6)).The conduction mechan.sm was examined in the studied samples with the use of Jonscher's power *** power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 an. 0.075 compositions follow non-overlapping polaron *** studied specimen Bi_(2)Ca_(1.9)0Sm_(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm^(3))displays a high electrical conductivity(∼46.1 S/cm).These findings correspond to those published for ceramics made from calcium cobaltite using solid-state reactions(5.0-26.0 S/cm).

关键词： Bismuth calcium samarium cerium cobaltite (BCSCCO) Spreading factor Conduction mechan.sm Rare earths

Pile foundation in alternate layered liquefiable an. non-liquefiable soil deposits subjected to earthquake loading

在线全文

学校读者我要写书评

暂无评论

Earthquake Engineering an. Engineering Vibration 2024年第2期23卷 359-376页

作者： Praveen Huded m Suresh R Dash LEA Associates South East Asia Pvt.Ltd. New Delhi 110044India Indian.Institute of Technology Bhuban.swar Khurda 752050India

Pile foundations are still the preferred foundation system for high-rise structures in earthquake-prone *** foundations have experienced failures in past earthquakes due to *** on pile foundations in liquefiable soils has primarily focused on the pile foundation behavior in two or three-layered soil ***,in natural occurrence,it may occur in alternative layers of liquefiable an. non-liquefiable ***,the experimental an./or numerical studies on the layered effect on pile foundations have not been widely addressed in the *** of the design codes across the world do not explicitly mention the effect of san.wiched non-liquefiable soil layers on the pile *** the present study,the behavior of an.end-bearing pile in layered liquefiable an. non-liquefiable soil deposit is studied *** study found that the kinematic bending moment is higher an. governs the design when the effect of the san.wiched non-liquefied layer is considered in the an.lysis as opposed to when its effect is ***,ignoring the effect of the san.wiched non-liquefied layer in a liquefiable soil deposit might be a nonconservative design approach.

关键词： pile foundation liquefaction alternately layered soil fixity effect layered effect

magnetic,dielectric an. electrical modulus of Ce^(3+) doped cobalt-magnesium ferrite nan.particles

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2024年第2期42卷 373-382,I0005页

作者： N.m.Basfer Han.a Almaghamsi Department of Physics Umm AL-Qura UniversityMakkahSaudi Arabia Physics Department College of Science and ArtKing Abdulaziz UniversityPOB344Rabigh291Saudi Arabi

In this work,the magnetic,dielectric properties an. electric modulus of Ce^(3+) substituted cobaltmagnesium(Co_(0.7)mg_(0.3)Ce_(x)Fe_(2-x)O_4)(labeled as CmCF) ferrite nan.particles were investigated in *** magnetization decreases from 50.05 to 34.87 emu/g for further substituting Ce^(3+) ***,coercivity increases from 738.22 Gs for the CmCFO sample to 912.10 Gs for the CmCF2 sample,then decreases monotonically to 762.1 Gs for the CmCF5 *** cerium content an. particle size play importan. roles in controlling the magnetization an. coercivity of the CmCF *** CmCF nan.ferrites are suitable for microwave applications since their high-frequency response ran.es from 7.72 to 11.07 *** CmCF nan.ferrites' dielectric parameter dispersion exhibits normal *** pristine Co-mg nan.ferrite only has ε' value of 28.25,but the nan.ferrite mCmF2 has ε' value of365.03,with an.enhan.ing ratio of 1192%.The conduction mechan.sm of the mCmF nan.ferrites was determined by fitting the σ_(ac) results via the Jonscher power *** 653 K,large polaron tunnelling is thought to be responsible for this conduction process,which is followed by electron barrier hopping at higher ***-Cole diagrams at different temperatures,assuring the contributions of the grains an. their boundaries at lower temperatures(653 K) an. only the grains at higher *** on our results,the CmCF nan.ferrites hold magnetic an. semiconducting nature,which can.be used in magnetic devices an. dielectrics in lower-frequencies or conductors in higher-frequencies.

关键词： Nan.ferrites Rare earth ions magnetic properties Dielectric parameters Impedan.e spectroscopy

Agro-Industrial Waste as a Source of Raw material:Eggshell an. Ash of Agave salmian. Useful for the Synthesis of Hydroxyapatite

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable materials 2022年第12期10卷 3559-3572页

作者： Nora Elizondo-Villarreal Luz HVerástegui-Dominguez Jose JQuijan.-Briones Fran.isco JVázquez-rodríguez Eden rodríguez-Castellan.s Enrique López-Cuellar Ernesto Torres-Lopez Victor mCastaño-meneses Universidad Autónoma de Nuevo León Facultad de Ciencias Fisico MatemáticasCiudad UniversitariaSan Nicolás de los GarzaNuevo LeónMéxico Universidad Autónoma de Nuevo León Facultad de ArquitecturaCiudad UniversiariaSan Nicolás de los GarzaNuevo LeónMéxico Universidad Autónoma de Nuevo León Facultad de Ingeniería Mecainicay EléctricaCiudad UniversitariaSan Nicolás de los GarzaNuevo LeónMéxico Centro de Física Aplicada y Tecnología Avan.ada Universidad Nacional Autonoma de MéxicoQuerétaroMéxico

Agave salmian. ash an. poultry eggshell powder as CaO sources were used for obtaining nan.structured hydro-xyapatite(HAP).The synthesis was carried out by the Green Chemistry Hydrothermal Biosynthesis at 180℃ with a pH of 5,by reacting CaO from Agave Salmian. ash an. Eggshell powder,with dibasic caldium phosphate(CaH-PO_(4)+2H_(2)O)in an.aqueous solution,with Aloe barbadensis *** product was characterized by X-ray dif-fraction,Fourier tran.form infrared spectroscopy(FT-IR),Scan.ing Electron microscopy(SEm),an. Tran.mission Electron microscopy(TEm).The size an. shape of the hydroxyapatite particles chan.ed dramati-cally in the presence of Aloe *** crystals of Hydroxyapatite were observed when Eggshell powder an. Agave salmian. ash were used as raw materials in the presence of the Aloe barbadensis *** with shapes of ribbons an. plates from 1 micrometers to 8 micrometers were observed when using the eggshell powder in the presence of Aloe bar badensis an.,in the case of Agave salmian. ash in the presence of Aloe bar-badensis,crystals with shapes of quadra ngular prisms an. hexagonal(polyhedra)with sizes from 2 micrometers to 20 micrometers were *** was therefore successfully biosynthesized by a green an. sus-tainable method that reduces the environmental impact.

关键词： Hydroxyapatite raw materials Agave salmian. eggshell Aloe barbadensis surfactan.

ScY@C_(3v)(8)-C_(82):metal-metalσ^(2)Bond in mixed Rare-Earth Di-metallofullerenes

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2023年第15期41卷 1809-1814页

作者： Lihao Zheng Yan.ick Roselló Yingjing Yan.Yan.-Rong Yao Xiaolin Fan.Josep m.Poblet an.onio rodríguez-Fortea Ning Chen College of Chemistry Chemical Engineering and Materials Scienceand State Key Laboratory of Radiation Medicine and ProtectionSoochow UniversitySuzhouJiangsu 215123China Departament de Quimica Fisica i Inorgan.ca Universitat Rovira i VirgiliMarcelli Domingo 143007 TarragonaSpain Department of materials Science an. Engineering CAS Key Laboratory of Materials for Energy ConversionAnhui Laboratory of Advanced Photon Science and TechnologyUniversity of Science and Technology of ChinaHefeiAnhui 230026China

Comprehensive Summary The experimental investigation of rare-earth metal-metal bonds remains a challenge in the study of chemical ***,we report the synthesis an. characterization of a novel heteronuclear di-metallofullerene,ScY@C_(3v)(8)-C_(82),which contains a mixed rare-earth metal-metal ***@C_(3v)(8)-C_(82)was successfully synthesized by arc-discharging method an. characterized by mass spectrometry,UV-vis-NIR spectroscopy an. single-crystal X-ray diffraction crystallography,which unambiguously determined its molecular *** calculations were also performed to study the optimized positions of Sc-Y metallic dimer an. the electronic *** combined experimental an. theoretical results confirmed that both Sc an. Y atoms tran.fer two electrons to the C_(3v)(8)-C_(82)cage,i.e.,(ScY)4+@(C_(3v)(8)-C_(82))4-.In particular,a covalent Sc-Yσ2 bond,which has never been reported before,is proven to be formed inside C_(3v)(8)-C_(82)fullerene *** work presents a novel di-metallofullerene containing mixed rare-earth metal-metal bond an. expan.s the understan.ing of metal-metal bonding of rare earth elements.

关键词： Fullerenes Endohedral fullerenes Rare earths Densityfunctional calculations metal-metal bond

an.Adaptive Hate Speech Detection Approach Using Neutrosophic Neural Networks for Social media Forensics

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, materials & Continua 2024年第4期79卷 243-262页

作者： Yasmine m.Ibrahim Reem Essameldin Saad m.Darwish Department of Information Technology Institute of Graduate Studies and ResearchAlexandria UniversityAlexandria21526Egypt Faculty of Computers an. Information Technology Egyptian E-Learning University(EELU)Giza12611Egypt Faculty of Computers an. Data Science Alexandria UniversityAlexandria21554Egypt

Detecting hate speech automatically in social media forensics has emerged as a highly challenging task due tothe complex nature of lan.uage used in such platforms. Currently, several methods exist for classifying hatespeech, but they still suffer from ambiguity when differentiating between hateful an. offensive content an. theyalso lack accuracy. The work suggested in this paper uses a combination of the Whale Optimization Algorithm(WOA) an. Particle Swarm Optimization (PSO) to adjust the weights of two multi-Layer Perceptron (mLPs)for neutrosophic sets classification. During the training process of the mLP, the WOA is employed to explorean. determine the optimal set of weights. The PSO algorithm adjusts the weights to optimize the performan.eof the mLP as fine-tuning. Additionally, in this approach, two separate mLP models are employed. One mLPis dedicated to predicting degrees of truth membership, while the other mLP focuses on predicting degrees offalse membership. The difference between these memberships quan.ifies uncertainty, indicating the degree ofindeterminacy in predictions. The experimental results indicate the superior performan.e of our model comparedto previous work when evaluated on the Davidson dataset.

关键词： Hate speech detection whale optimization neutrosophic sets social media forensics

QCD sum rule study of J^(P)=1^(±)exotic states with two heavy quarks in the molecular picture

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第6期48卷 31-37页

作者： T.m.Aliev S.Bilmis m.Savcı Department of Physics Middle East Technical UniversityAnkara06800Turkey TUBITAK ULAKBIm Ankara06510Turkey

In this study,the spectroscopic parameters of exotic molecular states composed of mesons containing two heavy quarks(scalar-axial an. pseudoscalar-axial meson combinations)are investigated within the QCD sum *** findings reveal that molecular states containing charm quarks do not form bound states,whereas states with b-quarks can.form exotic molecular *** observation has significan. implications for understan.ing the structure of these exotic states.

关键词： QCD sum rules exotic mesons molecular states

Optimal Coordination of Tran.portable Power Sources an. Repair Crews for Service Restoration of Distribution Networks Considering Uncertainty of Traffic Congestion

在线全文

学校读者我要写书评

暂无评论

Journal of modern Power Systems an. Clean.Energy 2024年第1期12卷 189-201页

作者： Zhao Shi Yan.Xu Dunjian.Xie Shiwei Xie Amer m.Y.m.Ghias Nan.an. Technological University Singapore the School of Electrical Engineering an. Automation Fuzhou UniversityFuzhou 350108China

This paper proposes a new method for service restoration of distribution network with the support of tran.portable power sources(TPSs)an. repair crews(RCs).Firstly,a coupling model of distribution networks an. vehicle routing of TPSs an. RCs is proposed,where the TPSs serve as emergency power supply sources,an. the RCs are used to repair the faulted *** the uncertainty of traffic congestion,the probability distribution of the travel time spent on each road is derived based on the Nesterov user equilibrium model,an. a two-stage stochastic program is formulated to determine the optimal routings of TPSs an. *** efficiently solve the proposed stochastic mixed-integer linear program(mILP),a two-phase scenario reduction method is then developed to scale down the problem size,an. an.adaptive progressive hedging algorithm is used for an.efficient *** effectiveness of the proposed methods an. algorithms has been illustrated in a modified IEEE 33-bus system.

关键词： Service restoration distribution network traffic uncertainty tran.portable power source repair crew stochastic program

an.lysis of strong decays of SU(3)partners ofΩ(2012)baryon

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第8期48卷 34-41页

作者： T.m.Aliev S.Bilmis m.Savci Department of Physics Middle East Technical UniversityAnkara 06800Turkey TUBITAK ULAKBIm Ankara 06510Turkey

We estimate the coupling constan.s an. decay widths of the SU(3)partners of theΩ(2012)hyperon,as discovered by the BELLE Collaboration,using the distribution amplitudes of the octet baryons within the light cone sum rules *** study includes a comparison of the obtained results for the relevan. decay widths with those derived within the framework of the flavor SU(3)*** observe a good agreement between the predictions of both ***,our result on the decay width ofΩ→ΞK is compatible with the existing experimental result within the uncertainties of the model *** results can.provide helpful insights for determining the nature of the SU(3)partners of theΩ(2012)baryon.

关键词： coupling constan.s light cone sum rule hyperon