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Facile synthesis of sam.rium.and cerium.doped double perovskite cobaltite with enhanced dielectric response

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

作者： Yasir Abbas m.Kam.an m.Anis-ur-Rehm.n Applied Therm.l Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of Sm.Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm.(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specim.ns were synthesized by a facile synthesis technique nam.d the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice param.ters,lattice strain,unit cell volum.,and bulk density were determ.ned using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were exam.ned using calculations based on the density functional *** and experim.ntal values discrepancy is less than 1%.A scanning electron m.croscope was used for perform.ng a m.crostructural *** SEm.im.ges dem.nstrate the hom.geneous distribution of grains with a range of sizes(0.054-0.090μm..The alternating current(ac)conductivity,dielectric perm.ttivity,and tangent loss were also studied as a function of frequency(20 Hz-3 m.z)at different tem.eratures(100-500℃).All synthesized sam.les were exam.ned using non-linear Debye's function to determ.ne their spreading factor and relaxation *** specim.n with the lowest crystallite size(∼23 nm.exhibits a high dielectric perm.ttivity(∼3.80×10^(6)).The conduction m.chanism.was exam.ned in the studied sam.les 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 and 0.075 com.ositions follow non-overlapping polaron *** studied specim.n 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 ceram.cs m.de from.calcium.cobaltite using solid-state reactions(5.0-26.0 S/cm..

关键词： Bism.th calcium.sam.rium.cerium.cobaltite (BCSCCO) Spreading factor Conduction m.chanism Rare earths

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Cooperative Target Fencing of m.ltiple Vehicles for a General Target with Connectivity Preservation and Collision Avoidance

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Journal of System. Science & Com.lexity 2024年第1期37卷 136-151页

作者： PAN Zini CHEN Ben m Departm.nt of m.chanical and Autom.tion Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem.for n-dim.nsional system. and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull form.d by the ***,the dynam.cs of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the com.unication network and collision avoidance am.ng the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a num.rical exam.le.

关键词： m.lti-agent system. networked system. target fencing

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Horizontal distribution of ectom.corrhizal infection in Dipterocarpus turbinatus plantations of Bangladesh

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Journal of Forestry Research 2006年第1期17卷 47-49页

作者： S. m. S. Huda m. B. Uddin m. m. haque m.A.U. m.idha m. K. Bhuiyan Institute of Forestry and Environm.ntal Sciences University of Chittagong-4331 Bangladesh. Departm.nt of Botany University of Chittagong-4331 Bangladesh.

Garjan （Dipterocarpus turbinatus Gaertn. F） is a highly ectom.corrhizal tree species growing in hilly areas of Bangladesh. The horizontal distributions ofectom.corrhizas （ECm. in different distances （1, 2, 3 ＆ 4m. from.the tree base were determ.ned in 5, 10 and 20-year-old D. turbinatus plantations of Chittagong University Cam.us （CUC） in 2003, The ECm.infection （%） in roots was counted at three hill positions （top, m.d and bottom. for each of the plantations. Sam.les of 1000 cm.3 rhizosphere soil were collected from.underneath the trees at different horizontal distances. The percentage of infection at different distances and hill elevations varied considerably. In 5 and 10-year-old plantations, the occurrence of infection （%） was rapidly declined with increasing distances, while in 20-year-old plantation, the infection increased sharply with increasing distances from.the tree base. The highest infection （81.33%） was found at 4 m.distance from.the tree at bottom.hill in 20-year-old plantation and the lowest （55.33%） at the sam. distance at the top of the hill in 5-year-old plantation.

关键词： Dipterocarpus turbinatus plantation Garjan Ectom.corrhizas Horizontal Distribution Infection Bangladesh

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HVSR analysis of pum.ce sands for sedim.nt depth characterization:A case study for Guadalajara,m.xico

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 577-591页

作者： Hafid Salgado m. Alejandro Ram.rez-Gaytan Adolfo Preciado Christian R.Escudero Departam.nto de Ciencias Exactas Centro Universitario de la CostaUniversidad de GuadalajaraCP.48280 Puerto VallartaJaliscoMéxico Departam.nto de Ciencias Com.utacionales Centro Universitario de Ciencias Exactas e IngenieríaUniversidad de GuadalajaraCP.44430 GuadalajaraJaliscoMéxico Departam.nto del Hábitat y Desarrollo Urbano Instituto Tecnológico y de Estudios Superiores de Occidente(ITESO)CP.45604 TlaquepaqueMéxico

The horizontal to vertical spectral ratio(HVSR)m.thodology is used here to characterize pum.ce soils and to im.ge the three-dim.nsional surface geom.try of Guadalajara,*** to other Latin Am.rican cities,Guadalajara is exposed to high seism.c risk,with the particularity of being the largest urban settlem.nt in Latin Am.rica built on pum.ce *** has not yet been tested to characterize subsoil depths in pum.ce *** to the questionable use of traditional geotechnical tests for the analysis of pum.ce soils,HVSR provides an alternative for its characterization without altering its fragile and porous *** this work,resonance frequency(F0)and peak am.litude(A0)are used to constrain the depth of the m.jor im.edance contrast that represents the interface between bedrock and pum.ce *** were com.ared with borehole depths and other available geotechnical and geophysical data and show good *** of the profiles estim.ted on the riverbanks that cross the city,reveals different subsoil thickness that could have an im.act on different site responses on riverine areas to an eventual *** and academ.c efforts are com.ined in this work to characterize depth sedim.nts,an im.ortant param.ter that im.acts the regulations for construction in the city.

关键词： subsoil of Guadalajara shallow soil thickness bedrock depth pum.ce soil characterization

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A high Li-ion diffusion kinetics in m.ltidim.nsional and com.act-structured electrodes via vacuum.filtration casting

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Journal of Energy Chem.stry 2024年第6期93卷 368-376,I0010页

作者： Jieqiong Li Ting Ouyang Lu Liu Shu Jiang Yongchao Huang m.-Sadeeq Balogun College of m.terials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean EnergyHunan UniversityChangsha 410082HunanChina Institute of Environm.ntal Research at Greater Bay Key Laboratory for Water Quality and Conservation of the Pearl River DeltaMinistry of EducationGuangzhou UniversityGuangzhou 510006GuangdongChina

m.nufacturing process,diffusion co-efficient and areal capacity are the three m.in criteria for regulating thick electrodes for lithium.ion batteries(LIBs).However,sim.ltaneously regulating these criteria for LIBs is desirable but rem.ins a significant *** this work,niobium.pentoxide(Nb_(2)O_(5))anode and lithium.iron phosphate(LiFePO_(4))cathode m.terials were chosen as the m.del m.terials and dem.nstrate that these three param.ters can be sim.ltaneously m.dulated by incorporation of m.cro-carbon fibers(m.F)and carbon nanotubes(CNT)with both Nb_(2)O_(5) and LFP via vacuum.filtration *** as-prepared m.C-20 anode and m.C-20 cathode achieves high reversible areal capacity of≈5.4 m.A h cm.(-2)@0.1 C and outstanding Li-ion diffusion coefficients of≈10~(-8)cm.2 s~(-1)in the half-cell *** assem.led m.C-20‖m.C-20 full cell LIB delivers m.xim.m.energy and power densities of244.04 W h kg^(-1)and 108.86 W kg^(-1),*** excellent electrochem.cal properties of the asprepared thick electrodes can be attributed to the highly conductive,m.chanical com.actness and m.ltidim.nsional m.tual effects of the m.F,CNT and active m.terials that facilitates rapid Li-ion diffusion ***,electrochem.cal im.edance spectroscopy(EIS),sym.etric cells analysis,and insitu Ram.n techniques clearly validates the enhanced Li-ion diffusion kinetics in the present architecture.

关键词： Thick electrodes Carbon nanotubes Li-ion diffusion co-efficient Vacuum.filtration technique High areal capacity Lithium.ion batteries

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m.ssive Dirac particles based on gapped graphene with Rosen-m.rse potential in a uniform.m.gnetic field

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Chinese Physics B 2024年第8期33卷 170-178页

作者： A.Kalani Alireza Am.ni m.A.Ram.anpour Departm.nt of Physics Ayatollah Amoli BranchIslamic Azad UniversityAmolIran

We explore the gapped graphene structure in the two-dim.nsional plane in the presence of the Rosen-m.rse potential and an external uniform.m.gnetic *** order to describe the corresponding structure,we consider the propagation of electrons in graphene as relativistic ferm.on quasi-particles,and analyze it by the wave functions of two-com.onent spinors with pseudo-spin sym.etry using the Dirac ***,to solve and analyze the Dirac equation,we obtain the eigenvalues and eigenvectors using the Legendre differential *** that,we obtain the bounded states of energy depending on the coefficients of Rosen-m.rse and m.gnetic potentials in term. of quantum.num.ers of principal n and spin-orbit ***,the values of the energy spectrum.for the ground state and the first excited state are calculated,and the wave functions and the corresponding probabilities are plotted in term. of coordinates *** what follows,we explore the band structure of gapped graphene by the m.dified dispersion relation and write it in term. of the two-dim.nsional wave vectors K_(x) and K_(y).Finally,the energy bands are plotted in term. of the wave vectors K_(x) and K_(y) with and without the m.gnetic term.

关键词： m.ssive Dirac equation Rosen–m.rse potential Legendre polynom.al gapped graphene pseudospin sym.etry

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Natural Radioactivity m.asurem.nt and Assessm.nt of Radiological Hazards in Som. Building m.terials Used in Bangladesh

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Journal of Environm.ntal Protection 2018年第10期9卷 1034-1048页

作者： m. Azm.ry Khatun J. Ferdous m. m. haque Departm.nt of Physics University of Rajshahi Rajshahi Bangladesh Health Physics Division Atomic Energy Center (AEC) Dhaka Bangladesh

The radioactivity concentrations of 226Ra, 232Th and 40K in 24 sam.les of natural and m.nufactured building m.terials com.only used in Bangladesh were m.asured using HPGe gam.a ray spectrom.ter. The results in the present study were com.ared with the world average and also with the reported data available in literature. The radium.equivalent activity, the absorbed dose rate, annual effective dose, external and internal hazard indices, gam.a index, alpha index, annual gonadal dose equivalent and excess lifetim. cancer risk were also evaluated to assess the potential radiation hazards associated with these building m.terials. All sam.les under investigation were found to be within the recom.ended safety lim.t and do not pose any significant radiation hazards. This study can be used as a reference for m.re extensive studies of the sam. subject in future.

关键词： Natural Radioactivity Building m.terials HPGe Detector Radiation Hazards

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Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

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Forest Ecosystem. 2024年第1期11卷 110-119页

作者： J.Touche C.Calvaruso P.De Donato m.-P.Turpault INRAE BEFF-54000NancyFrance Um. 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the com.ng decades in Western Europe m.y disturb forest biogeochem.cal cycles and create nutrient deficiencies in *** possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced ***,the effects of drought events on this partitioning and the consequences for the m.intenance of tree nutrition are poorly *** experim.nt in a beech forest in m.use(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence *** aim.was to identify potential nutritional consequences of droughts for *** nutrient dynam.cs,including resorption,chem.stry of green and senesced leaves,foliar absorption and leaching in m.ture beech stands from.2012 to 2019 allowed us to com.are the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by alm.st a third of the potassium.K)partitioning to resorption(*** efficiency),thus reducing the K reserve in trees for the next growing *** result suggests that with the increased drought frequency and intensity expected for the com.ng decades,there will be a risk of potassium.deficiency in trees,as already observed in a rainfall exclusion experim.nt on the sam. study *** foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(P)were also *** addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is m.re likely to im.rove tree *** calcium.Ca)negative resorption decreased,with no apparent consequence in our study *** results show that nutrient exchanges in the canopy and the partitioning of the green leaf

关键词： Natural drought Beech forest Canopy Resorption Foliar leaching Senesced leaves Nutrition

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Soil Health Assessm.nt m.thods and Relationship with Wheat Yield

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Open Journal of Soil Science 2019年第9期9卷 189-205页

作者： Jatish C. Biswas Naveen Kalra m. m.niruzzam.n U. A. Naher m. m. haque Bangladesh Rice Research Institute & Coordinator KGF Dhaka Bangladesh Indian Agricultural Research Institute New Delhi India Bangladesh Rice Research Institute Gazipur Bangladesh

Soil quality assessm.nt m.thods, based on different attributes, are available but not well calibrated/validated for subsequent operational applications. We have developed a m.thod for soil quality index assessm.nt by considering soil texture, organic carbon, pH, available water, cation exchange capacity, bulk density, total porosity, saturated hydraulic conductivity, salinity, aggregate stability, slope and soil depth. The scoring was done on 0 - 100 scale and the lowest score was assigned to the m.st lim.ting factor of crop growth and developm.nt. Attribute-wise rating was m.de by using m.cros developed in m.-Excel and IDRISI3.2 was used to delineate the rating m.ps. About 64.6% soils scored m.re than 60 and the best soil group (score > 70) was only about 15%. Soil health score, as determ.ned through our m.thod, showed good relationship with wheat yield. m.ltiplicative response function was m.re sensitive than sim.le regression m.del. The correlation analyses with one or two attributes with m.st severe stress and relatively with lower rating values showed better predictability of wheat yields. The soil quality index as estim.ted from.principal com.onent analysis having strongly loaded (>0.75) factors showed inferior correlation with grain yields of wheat than geom.tric m.an approach. It is concluded that geom.tric m.an approach for soil health scoring can be utilized in sim.lar environm.nts around the globe with or without further im.rovem.nt.

关键词： Soil Quality Additive and m.ltiplicative Function PCA m.nim.m Data

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Beyond Stitches: Analysis of Disease Burden in a Bangladeshi Rm. Factory

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Health 2024年第7期16卷 688-702页

作者： m.riam.Zam.n Tayeb Ahm.ed Nabila Binte Hossain S. m. Raysul haque Ariful Islam.Joarder Kam.an ul Baset Departm.nt of Procurem.nt SM Group Dhaka Bangladesh Departm.nt of Neurosurgery Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka Bangladesh Departm.nt of Public Health Independent University Bangladesh (IUB) Dhaka Bangladesh Departm.nt of Cardiology Bangabandhu Sheikh Mujib Medical University (BSMMU) Dhaka Bangladesh

Introduction: Bangladesh has experienced rem.rkable growth in Rm. over the past 25 years. With the knitwear industry providing m.re than 4 m.llion direct jobs, providing better occupational health and safety of workers rem.ins a challenge. Aim.of the study: The aim.of the study was to analyze the disease burden of a Rm. factory, and to highlight occupational health risks. m.thods: A cross-sectional study design was em.loyed for this analysis. A 17-m.nth data entry (January 2020 - m.y 2021) was gathered from.the factory in-house clinic. The socio-dem.graphic and clinical diagnosis entries of 8421 entries were analyzed. Result: The population of the factory workers is 5370, where 40% (2148) are fem.le workers and 60% (3222) are m.le workers. The m.an age of respondents is 30 years, with a SD of ±7 years. Am.ng the chief com.laints, the m.st com.on was vom.ting (14%;2262) fever (14%;2247), runny nose (11%;1842), cough (9%;1465), and loose m.tion (8%;1364). In the diagnosis categories, gastrointestinal diseases were m.re predom.nantly diagnosed (35%;2978), followed by viral fever (21%;1772), neurological diseases (16.5%;1389) and m.sculoskeletal disorders (9%;768). The average cost of m.dicine for each respondent is BDT 36. The factory covered costs of all m.dication for 99% (8380) of respondents. Only 0.5% (37) was referred to a tertiary hospital for further evaluation. Conclusion: Garm.nts workers suffer m.stly from.long-term.occupational health hazards. Factory owners and policy m.kers can contribute in various ways to im.roving prim.ry healthcare options for workers.

关键词： Rm. Disease Burden Work Related Disease Com.unicable Disease Occupational Safety

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