检索结果-南通市图书馆

Facile synthesis of samarium 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.Kamran M.anis-ur-Rehman Applied Thermal 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 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,and bulk density were determined using XRd *** structural properties of Bi_(2)Ca_(2)CoO_(6)were examined using calculations based on the density functional *** and experimental values discrepancy is less than 1%.A scanning electron microscope was used for performing a microstructural *** sEM images demonstrate the homogeneous distribution of grains with a range of sizes(0.054-0.090μm).The alternating current(ac)conductivity,dielectric permittivity,and tangent 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 and relaxation *** specimen with the lowest crystallite size(∼23 nm)exhibits a high dielectric permittivity(∼3.80×10^(6)).The conduction mechanism 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 and 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 mechanism Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adsorption of yttrium(Y^(3+)) and concentration of rare earth elements from phosphogypsum using chitin and chitin aerogel

引用

Journal of Rare Earths 2024年第4期42卷 775-782页

作者： Glaydson s.dos Reis diana Pinto sabrina F.lütke Eder C.lima luis F.O.silva Irineu A.s.de Brum Guilherme l.dotto department of Forest Biomaterials and Technology Biomass Technology Centre Swedish University of Agricultural SciencesUmeaE13Swedn Universidad de la Costa Calle 58#55-66080002BarranquillaAtlanticoColombia Research Group on Adsorptive and Catalytic Process Engineering(ENGEPAC) Federal University of Santa MariaAv.Roraima100079705900Santa MariaRSBrazil Institute of Chemistry Federal University of Rio Grande do Sul90040060Porto AlegreBrazil

Chitin powder and chitin-aerogel were prepared from shrimp wastes and used to uptake Y^(3+)from aqueous solutions and concentrate this rare earth element from phosphogypsum(PG).Chitin aerogel displays a specific surface area of 945 m^(2)/g,while chitin powder is 3.6 m^(2)/g,which largely influences its adsorption *** the adsorption in synthetic solutions,the effect of pH on Y^(3+)removal is strong for chitin powder *** contrast,no big pH influence was detected for chitin *** interactions and chelation can highlight the proposed mechanism of Y^(3+)on chitin adsorbents for the powder and ***,in addition to these interactions,pore filling/pore diffusion is the main mechanism of Y^(3+)removal in the chitin *** aerogel is efficient in concentrating 8 times the Y^(3+)from PG,a very complex *** complex chitin aerogel-Y^(3+)can be a secondary source of rare earth elements for other applications.

关键词： Rare earths sustainable material Chitin powder Chitin porous aerogel Yttrium adsorption and recovery

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Metal-modulated epitaxy of Mg-doped Al_(0.80)In_(0.20)N-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

引用

Journal of semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán solís-Cisneros Carlos Alberto Hernández-Gutiérrez Enrique Campos-González Máximo lópez-lópez Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico departamento de Física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico departamento de Física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-AlInN layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).AlInN was grown with an Al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on si(111)substrates using AlN as buffer *** substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRd).Cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPs)estimating the alloy composition and extracting the Fermi level by valence band ***-doped AlInN layers were studied for use as the electron-blocking layer(EBl)in lEd *** varied the Al composition in the EBl from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using sIlVACO *** results from this study highlight the importance and capability of producing high-quality Mg-doped p-AlInN layers through *** simulations suggest that an Al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy AlInN dUV-lEd EBl simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

development and testing of a high-power s-band klystron at BINP sB RAs

引用

Nuclear science and Techniques 2024年第7期35卷 58-67页

作者： A.levichev A.Barnyakov s.samoylov d.Nikiforov V.Ivanov M.Arsentyeva d.Chekmenev O.Pavlov I.Pivovarov Budker Institute of Nuclear Physics Lavrentyeva Av.11NovosibirskRussia630090 Novosibirsk state University Pirogova Str.2NovosibirskRussia630090

This paper details the development and testing of the first working prototype of the s-band high-power klystron,accomplished at the Budker Institute of Nuclear Physics,siberian Branch,Russian Academy of sciences(BINP sB RAs).Upon testing,the klystron demonstrated the following parameters:an operating frequency of 2856 MHz and a peak power output of 50 *** paper presents the klystron's design,its constituent units,and pertinent processing procedures,along with discussions on the measurement of its parameters.

关键词： Klystron linear accelerator Electron beam

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Isochrone Fitting of Galactic Globular Clusters—Ⅵ.High-latitude Clusters NGC 5024 (M53),NGC 5053,NGC 5272 (M3),NGC 5466,and NGC7099 (M30)

引用

Research in Astronomy and Astrophysics 2024年第6期24卷 170-190页

作者： G.A.Gontcharov s.s.savchenko A.A.Marchuk C.J.Bonatto O.s.Ryutina M.Yu.Khovritchev V.B.Il'in A.V.Mosenkov d.M.Poliakov A.A.smirnov Central(Pulkovo)Astronomical Observatory Russian Academy of SciencesPulkovskoye chaussee 65/1St.Petersburg 196140Russia saint Petersburg state University Universitetskij pr.28St.Petersburg 198504Russia special Astrophysical Observatory Russian Academy of Sciences369167 Nizhnij ArkhyzRussia departamento de Astronomia Instituto de FísicaUFRGSAv.Bento Gonçalves9500Porto AlegreRSBrazil saint Petersburg University of Aerospace Instrumentation Bol.Morskaya ul.67ASt.Petersburg 190000Russia department of Physics and Astronomy Brigham Young UniversityN283 ESCProvoUT 84602USA

We fit various color–magnitude diagrams(CMds) of the high-latitude Galactic globular clusters NGC 5024(M53),NGC 5053,NGC 5272(M3),NGC 5466,and NGC 7099(M30) by isochrones from the dartmouth stellar Evolution database and Bag of stellar Tracks and Isochrones for α–enrichment [α/Fe] = +*** the CMds,we use data sets from Hubble space Telescope,Gaia,and other sources utilizing,at least,25 photometric filters for each *** obtain the following characteristics with their statistical uncertainties for NGC 5024,NGC 5053,NGC 5272,NGC 5466,and NGC 7099,respectively:metallicities [Fe/H] =-1.93 ± 0.02,-2.08 ± 0.03,-1.60 ± 0.02,-1.95 ± 0.02,and-2.07 ± 0.04 dex with their systematic uncertainty 0.1 dex;ages 13.00 ± 0.11,12.70 ± 0.11,11.63 ± 0.07,12.15 ± 0.11,and 12.80 ± 0.17 Gyr with their systematic uncertainty 0.8 Gyr;distances(systematic uncertainty added) 18.22 ± 0.06 ± 0.60,16.99 ± 0.06 ± 0.56,10.08 ± 0.04 ± 0.33,15.59 ±0.03 ± 0.51,and 8.29 ± 0.03 ± 0.27 kpc;reddenings E(B-V) = 0.023 ± 0.004,0.017 ± 0.004,0.023 ± 0.004,0.023 ± 0.003,and 0.045 ± 0.002 mag with their systematic uncertainty 0.01 mag;extinctions av= 0.08 ± 0.01,0.06 ± 0.01,0.08 ± 0.01,0.08 ± 0.01,and 0.16 ± 0.01 mag with their systematic uncertainty 0.03 mag,which suggest the total Galactic extinction av= 0.08 across the whole Galactic dust to extragalactic objects at the North Galactic *** horizontal branch morphology difference of these clusters is explained by their different metallicity,age,mass-loss efficiency,and loss of low-mass members in the evolution of the core-collapse cluster NGC 7099 and loose clusters NGC 5053 and NGC 5466.

关键词： (stars:)Hertzsprung Russell and C-M diagrams (IsM:)dust extinction (Galaxy:)globular clusters:general (Galaxy:)globular clusters:individual(NGC 5024,NGC 5053,NGC 5272,NGC 5466,NGC7099)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

spatial analysis of dengue through the reproduction numbers relating to socioeconomic features:Case studies on two Brazilian urban centers

引用

Infectious disease Modelling 2024年第1期9卷 142-157页

作者： Ana T.C.silva Rejane C.dorn lívia R.Tomás leonardo B.l.santos lacita M.skalinski suani T.R.Pinho departamento de Física Universidade Estadual de Feira de SantanaAv.Transnordestinas/n.Novo HorizonteFeira de Santana44036-900BABrazil Instituto de Física Universidade Federal da BahiaRua Barão de Jeremoabo s/nCampus Universitário de OndinaSalvador40170-115BABrazil Centro Nacional de Monitoramento e Alertas de desastres Naturais(CEMAdEN) Estrada Dr.Altino Bondensan500São Josédos Campos12247-016SPBrazil Universidade Estadual de santa Cruz Campus Soane Nazaréde AndradeRodovia Jorge AmadoKm 16SalobrinhoIlhéus45662-900BABrazil Instituto de saúde Coletiva Universidade Federal da BahiaR.Basílio da Gamas/n-CanelaSalvador40110-140BABrazil Instituto Nacional de Ciência e Tecnologia-sistemas Complexos Virtual InstitutionBrazil

The study of the propagation of infectious diseases in urban centers finds a close connection with their population's social characteristics and *** work performs a spatial analysis of dengue cases in urban centers based on the basic reproduction numbers,R0,and incidence by planning areas(PAs),as well as their correlations with the Human development Index(HdI)and the number of *** analyzed dengue epidemics in 2002 at two Brazilian urban centers,Belo Horizonte(BH)and Rio de Janeiro(RJ),using PAs as spatial *** results reveal heterogeneous spatial scenarios for both cities,with very weak correlations between R0 and both the number of trips and the HdI;in BH,the values of R0 show a less spatial heterogeneous pattern than in *** BH,there are moderate correlations between incidence and both the number of trips and the HdI;meanwhile,they weakly correlate for ***,the absence of strong correlations between the considered measures indicates that the transmission process should be treated considering the city as a whole.

关键词： dengue Mathematical mode lBasic reproduction number Urban mobility Urban indices

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Microbial phenolic metabolites are associated with better frontal lobe cognition

引用

Food science and Human Wellness 2024年

作者： Inés domínguez-lópez Isabella Parilli-Moser Anna Vallverdú-Queralt Anna Tresserra-Rimbau Cinta Valls-Pedret Zenaida Vázquez-Ruiz Olga Casta?er Ramon Estruch Emili Ros Rosa M.lamuela-Raventós lipid Clinic， Endocrinology and Nutrition service， Institut d'Investigacions Biomèdiques August Pi i sunyer， Hospital Clínic 08036 Barcelona， Spain Unit of Cardiovascular Risk and Nutrition， Institut Hospital del Mar de Investigaciones Médicas (IMIM) department of Preventive Medicine and Public Health， University of Navarra departament de Nutrició， Ciències de l'Alimentació i Gastronomía， Facultat de Farmacia， Universitat de Barcelon (UB)， av.de Joan XXII department of Endocrinology， Hospital Clinic IDIBAPS， Barcelona， Spain department of Internal Medicine， Hospital Clinic， Institut d'Investigació Biomèdica August Pi i sunyer (IdIBAPs)， University of Barcelona CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN)， Instituto de salud Carlos III Institut de Nutrició i seguretat Alimentària (INsA)， Universitat de Barcelona (UB)

With increasing life expectancy， neurodegenerative diseases have become one of the leading causes of ill-health in the elderly. Preventive strategies include following healthy diets， such as the Mediterranean diet， which is particularly rich in polyphenols， bioactive compounds with neuroprotective properties. The aim of this study was to assess the association of microbial phenolic metabolites (MPM) with cognition. This cross-sectional analysis was performed with 200 participants of the PREdIMEd trial (Barcelona-Clinic recruitment center). A novel method based on liquid chromatography coupled to mass spectrometry was used to identify urinary MPM (protocatechuic acid， enterodiol glucuronide， enterolactone glucuronide， urolithin B glucuronide， and vanillic acid glucuronide)， and cognitive function was evaluated with neuropsychological tests. Multivariable-adjusted ordinary least squares regression was used to assess the associations between cognitive function and MPM， and a score was calculated as the weighted sum of MPM. A higher MPM score was associated with better frontal lobe function. Among individual metabolites， vanillic acid glucuronide was correlated with frontal cognitive performance. Participants with higher concentrations of vanillic acid glucuronide and urolithin B glucuronide obtained better scores in the Color Trail Test part 2. A higher score for urinary multi-MPM was associated with better frontal cognitive performance in an older Mediterranean population.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Vegetation Response To soil And Morphological Properties In An Arid Region Alluvial Fan landscape. Pre-Andes Of san Juan， Argentina

引用

Journal of Earth science 2024年

作者： FlOREs daniel Germán OCA?A Raúl Emmanuel MElIáN Edgardo ORTeg Andrés EsPER ANGIllIERI María Yanina PITTAlUGA María Alejandra CIGEOBIO (CONICET-UNsJ) av.José I.de la Roza y Meglioli Gabinete de Geología Ambiental， INGEO， Universidad Nacional de san Juan， av.José I.de la Roza y Meglioli

The Monte desert is characterized by a great diversity of landforms created with fluvial， alluvial which the vegetation patterns are related to. The present work has the following objectives: 1: determine whether topographical attributes， surface characteristics， soil properties and vegetation patterns vary between alluvial landforms， and 2: define whether morphometric， soil and surface properties influence vegetation patterns along alluvial landscape. Morphometric data were obtained by processing a 5 m digital elevation model. The coverage of rock fragments， fine sediments and mulch was quantified. Observations and descriptions of the soil profiles were restricted to the uppermost 50 cm. Vegetation properties were calculated using a Point Quadrat Method. The relationship between variables was evaluated through multivariate statistical analysis. The main results show the presence of 45 plant species distributed in 19 families， where shrubs are dominant. The wind effect， topographic wetness and dissection of the landscape are limiting factors of diversity. The coverage of superficial rock fragments influence vegetation coverage through the distribution and availability of rainwater. Furthermore， the different soil textures reveal that the silt content favors an increase in vegetation coverage. The presence of V horizon could condition the installation and development of vegetation in the early stages of growth.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

linear and nonlinear optical analysis on semiorganic-proline cadmium chloride single crystal

引用

Chinese Physics B 2018年第4期27卷 476-482页

作者： Mohd anis M I Baig s s Hussaini M d shirsat Mohd shkir H A Ghramh department of Physics Sant Gadge Baba Amravati University Amravati-444602 Maharashtra India Ram Meghe College of Engineering and Management Amravati-444701 Maharashtra India Crystal Growth laboratory Department of Physics Milliya Arts Science and Management Science College Beed431122 Maharashtra India RUsA Center for Advanced sensor Technology Department of Physics Dr. Babasaheb-Ambedkar-Marathwada University A urangabad-431005 Maharashtra India Research Center for Advanced Materials science (RCAMs) King Khalid University P. O. Box 9004 Abha-61413 Saudi Arabia Advanced Functional Materials & Optoelectronic laboratory (AFMOl) Department of Physics College of Science King Khalid University P. O. Box 9004 Ahha-61413 Saudi Arabia

In the current investigation,l-proline cadmium chloride monohydrate（lPCC） single crystal is grown by a slow solvent evaporation technique to identify its credibility for nonlinear optical device *** constituent elements of lPCC crystal are determined by the energy dispersive spectroscopic（Eds） *** single crystal x-ray diffraction technique is used to determine the structural dimensions of lPCC *** UV-visible studies are carried out within a wavelength range of 200 nm–1100 nm to determine the optical transmittance of lPCC *** linear optical parameters of lPCC crystal are evaluated using the transmittance data to discuss its importance for distinct optical *** Nd：YAG laser assisted Kurtz–Perry test is carried out to determine the enhancement in second harmonic generation efficiency of lPCC crystal with reference to KdP *** Z-scan technique is employed to assess the third order nonlinear optical（TONlO） properties of lPCC crystal at 632.8 *** Z-scan data are utilized to evaluate the TONlO refraction,absorption and susceptibility of lPCC *** color oriented luminescence behavior of lPCC crystal is investigated within a spectral range of 350 nm–700 *** dependence of dielectric constant and dielectric loss on temperature and frequency is evaluated through the dielectric measurement studies.

关键词： crystal growth dielectric studies nonlinear optical materials optical studies

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

HVOF-sprayed HAp/s53P4 BG composite coatings on an AZ31 alloy for potential applications in temporary implants

引用

Journal of Magnesium and Alloys 2024年第1期12卷 345-360页

作者： Carlos A.Poblano-salas John Henao Astrid l.Giraldo-Betancur Paola Forero-sossa diego German Espinosa-Arbelaez Jorge A.González-sánchez luis R.dzib-Pérez susana T.Estrada-Moo Idelfonso E.Pech-Pech CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-Cinvestav Libramiento Norponiente#2000.Fraccionamiento Real de JuriquillaQuerétaro 76230Mexico Universidad Tecnológica de Querétaro Av.Pie de la Cuesta N°2501Querétaro 76148Mexico CIdEsI Av.Playa Pie de la Cuesta No 702Col.San PabloQuerétaro 76125Mexico Center for Corrosion Research Autonomous University of CampecheAv.Héroe de Nacozari No.480P.C.24070San Francisco de CampecheCam.Mexico

Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro *** the present work,75%***-25%wt.s53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/s53P4 BG composite coatings on a bioresorbable AZ31 *** study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those *** characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite *** results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal *** was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the *** addition,in-vitro electrochemical studies were performed on the obtained HAp/s53P4 BG composite coatings and compared against the uncoated AZ31 *** results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(sBF).

关键词： Coatings Composites Thermal spray Temporary implants Hydrogen evolution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：