检索结果-南通市图书馆

Photoluminescence upgradation of la_(2)MgTiO_(6):2%Dy^(3+) perovskite with monovalent(Li^(+)),divalent(Ba^(2+),sr^(2+)) and trivalent(Bi^(3+),sm^(3+))cation sensitization

引用

Journal of Rare Earths 2025年第1期43卷 47-56,I0002页

作者： V.P.Veena k.Arun C.k.shilpa s.V.Jasira k.M.Nissamudeen school of Pure and Applied Physics Kannur UniversityPayyanur CampusEdatKannurKrala67 India Department of Nanoscience and Nanotechnology Kannur UniversityPayyanur CampusEdatkannurKerala670327India

Nano phosphors of 2%Dy^(3+)(wt%)doped la_(2)MgTiO_(6) and monovalent/divalent/trivalent co-doped la_(1.98)Dy_(0.02)MgTiO_(6):x%A^(y+)(A^(y+):Li+,Ba^(2+),sr^(2+),Bi^(3+),and sm^(3+);0≤x≤2 wt%)were synthesized by combustion *** the XRD data,it is deduced that an increase in the valency of co-dopant increases the crystallinity of the double perovskite orthorhombic nanocrystal *** an increase in co-dopant size,an elevation in optical bandgap is visible with the highest bandgap of 3.835 eV for Bi^(3+).The photo-absorption is monotonically broadened for sr^(2+),sm^(3+),and Li+around 200-450 ***351 nm,Dy^(3+)triggered lattice shows major characteristic emission peaks at 480 nm(^(4)F_(9/2)→^(6)H_(15/2)),574 nm(^(4)F_(9/2)→^(6)H_(13/2)),and 670 nm(^(4)F_(9/2)→^(6)H_(11/2)).leading to near white light emission with CIE coordinates(0.341,0.376).Upon co-doping,the PL intensity is significantly increased with maximum emission for trivalent sm^(3+),followed by divalent sr^(2+)and monovalent Li+*** increasing excitation wavelength,sr^(2+)shows a dominated output and it is found that divalent sr^(2+)is a potential codopant that could enhance luminescence intensity up to 6 times with a sr^(2+)→Dy^(3+)energy transfer efficiency of 86%.It is specified that the CIE coordinates of Li+co-doped samples show ideal white emission with color coordinates(0.333,0.336).The concluding outcomes signify the noblest rare earth sm^(3+)co-doping and thus sm^(3+)→Dy^(3+)energy transfer mechanism is discussed in detail.

关键词： Photoluminescence Perovskite WLED Co-doping Rareearths

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

Geochemistry and mineral chemistry of granitic rocks from west Wadi El Gemal area,southern Eastern Desert of Egypt:Indicators for highly fractionated syn-to post-collisional Neoproterozoic felsic magmatism

引用

Acta Geochimica 2025年第1期44卷 163-188页

作者： Hesham Mokhtar Adel A.surour Mokhles.k.Azer Minghua Ren Amir said Department of Geology Faculty of ScienceCairo UniversityGiza 12613Egypt Department of Geological sciences Faculty of ScienceGalala UniversityNew Galala City 43511Egypt Department of Geological sciences National Research CentreDokkiGiza 12622Egypt Department of Geoscience University of Nevada Las VegasLas VegasNV 89154-4010USA

Leucogranite,pegmatite,and aplite from selected areas in the Wadi El Gemal area in the southern Eastern Desert of Egypt were investigated geochemically for their *** rocks represent a significant episode of felsic magmatism during the late stage of the Pan-African orogeny in the evolution of the Arabian–Nubian shield(ANs)during the late *** a petrographic basis,the leucogranite is sometimes garnetiferous and can be distinguished into monzogranite,syenogranite,and alkali feldspar *** analyses of muscovite,biotite,garnet,and apatite reveal the magmatic nature of the studied *** investigated leucogranite,pegmatite,and aplite are alkali-calcic,calc-alkaline,and *** peraluminous nature of these rocks is evidenced by using the chemical analyses of *** studied rocks show a slight enrichment in light rare-earth elements(LREEs)and large-ion lithophile elements(LILE,especially Rb and Th),with an insignificant depletion of heavy rareearth elements(HREEs).On a geochemical basis,the leucogranite,pegmatite,and aplite in the study area crystallized from multiple-sourced melts that include mafic,metagraywake,and *** were derived from melts generated at crystallization temperatures around 568-900℃ for leucogranite,553-781℃ for pegmatite,and 639-779℃ for aplite based on the Zr saturation geothermometers,and at a pressure around 0.39-0.48 GPa,*** depth *** studied felsic rocks have strong negative Eu anomalies,which are very consistent with an upper crust composition,indicating fractionation of feldspar ***,they show a moderate la/sm ratio indicating combined magmatic processes represented by partial melting and fractional *** of whole-rock chemical composition and mineral microanalysis suggests that felsic magmatism in the west Wadi El Gemal area produced voluminous masses of syn-to post-collisional granite,pegmatite,and *** evolutionary three-

关键词： Leucogranite Pegmatite Aplite Wadi El Gemal Petrogenesis syn-collisional Post-collisional

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

laser interaction with undercritical foams of different spatial structures

引用

Matter and Radiation at Extremes 2025年第1期10卷 39-47页

作者： J.Limpouch V.Tikhonchuk O.Renner sh.Agarwal T.Burian J.Cervenka J.Dostál R.Dudzák D.Ettel A.Gintrand L.Hudec L.Juha O.klimo M.krupka M.krus T.lastovicka R.Liska W.Nazarov s.k.singh M.Šilhavík s.Weber Faculty of Nuclear science and Physical Engineering Czech Technical University in Prague11519 PragueCzech Republic The Extreme Light Infrastructure ERIC ELI-Beamlines FacilityZa Radnicí83525241 DolníBrezanyCzech Republic Centre lasers Intenses et Applications University of Bordeaux-CNRS-CEA351 Cours de la Liberation33405 TalenceFrance Institute of Physics Czech Academy of SciencesNa Slovance 1999/218200 PragueCzech Republic Institute of Plasma Physics Czech Academy of Sciences18200 PragueCzech Republic Faculty of Mathematics and Physics Charles University12116 PragueCzech Republic Faculty of Mechatronics Informatics and Interdisciplinary StudiesTechnical University of Liberec46117 LiberecCzech Republic Independent Foam Target supplier St.AndrewsFifeScotland

The interaction of high-power laser pulses with undercritical foams produced by different techniques but with the same average density is studied at the PALs laser *** spatial-temporal evolution of X-ray emission is observed using an X-ray streak camera,electron and ion temperatures are measured by X-ray spectroscopy,and hot-electron production is characterized by monochromatic X-ray *** of a femtosecond laser probe pulse through foams is observed in the near and far *** spite of large differences in pore size and foam structure,the velocity of ionization front propagation is quite similar for all the foams studied and is slower than that in a homogeneous material of the same average *** ion temperature in the plasma behind the ionization front is a few times higher than the electron ***-electron production in plastic foams with small pores is strongly suppressed compared with that in solid targets,whereas in foams produced by additive manufacturing,it is significantly increased to the level observed in bare copper foil targets.

关键词： temperature. interaction critical

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

The Potential of Wacapou (Vouacapoua americana) Extracts to Develop New Biobased Protective solutions for Low-Durability Wood species

引用

Journal of Renewable Materials 2025年第1期13卷 79-100页

作者： Emma kieny kévin Candelier Louis Milhe Yannick Estevez Cyrielle sophie Romain Lehnebach Jérémie Damay Daniela Florez Emeline Houël Marie-France Thévenon Julie Bossu CIRAD Ecologie de Forêts de Guyane(EcoFoG)AgroparisTechCNRSINRAEUniversitéde GuyaneKourou97379France CIRAD UPR BioWooEBMontpellierF-34398France BioWooEB Universitéde MontpellierCIRADMontpellierF-34398France CNRs Ecologie de Forêts de Guyane(EcoFoG)AgroparisTechCIRADINRAEUniversitéde GuyaneKourouGuyane Française97379France sorbonne Université CNRSLaboratoire de Biodiversitéet Biotechnologies MicrobiennesLBBMObservatoire OcéanologiqueBanyuls-sur-Mer66650France

The valorization of Amazonian wood residues into active chemical compounds could be an eco-friendly,cost-effective and valuable way to develop wood preservative formulations to enhance the decay and termite resistance of low-durable wood ***(Vouacapoua americana.,Fabaceae)is a well-known Guianese wood spe-cies commonly used in local wood construction due to its outstanding natural durability,which results from the presence of a large panel of extractives *** addition,its industrial processing generates large amounts of *** residues were extracted by maceration using four different solvents(water/ethanol,ethyl acetate,hexane and dichloromethane/methanol),separately and *** yield of each extractive fraction was determined,and their chemical compositions were analyzed by Liquid Chromatography-Mass spectrometry(LC-Ms).Ethyl acetate led to the highest extraction yield,and the active compounds were identiﬁed in the obtained extractive *** this sense,the fungicidal and termite-repellent properties of these extractives were then tested using a screening laboratory(with temperate and tropical microorganisms),according to the solution concentration(1%,2.5%,5%,8%and 10%).Finally,Virola michelii Heckel wood samples(low durable species)were impregnated with the 8%concentration *** impregnated wood samples were then exposed to a soil bed *** results highlighted that the nature of the solvent used during wood maceration affects the con-tent of the obtained extractive ***-Performance Liquid Chromatography–High-Resolution Mass spectrometry(UHPLC-HRMs)analyses showed the inﬂuence of extraction parameters on the nature of the extracted *** extracts(from ethyl acetate maceration)showed good anti-fungal and anti-termite ***,the concentration in extractives had an impact on the anti-termite activity level for Reti-culitermesﬂavipes and Cryptotermes *** based on W

关键词： Anti-fungal and anti-termite activities conferred durability extractives French Guiana impregnation guianese species wood by-products

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

la3+ substitution-adjusted magnetic and optical properties with enhanced photocatalytic activity and stability of copper zinc nickel ferrites for wastewater treatment applications

引用

Journal of Rare Earths 2025年第2期43卷 319-328页

作者： N.s.Al-Bassami General studies Department Jubail Industrial College

Copper-zinc-nickel（Cu-Zn-Ni） ferrite nanoparticles are used for wastewater treatment ***,low degradation efficiency and stability are two main issues that make them unsuitable for actual production *** this paper,the citrate-nitrate auto-combustion method was applied for the formation of Cu0.5Zn0.25Ni0.25laxFe2-xO4;（0≤x≤0.1;step 0.02）(CZNL) *** the substitution process entails the replacement of a small ion with a larger one,the lattice constant and crystallite size does not exhibit a consistent incremental *** behavior is justified and *** size of all the CZNL ferrite nanoparticles is in the range of 8-12 nm,and the lattice constant is in the range of 8.6230 to 8.4865 *** morphological analysis conducted using field emission-scanning electron microscopy（FE-sEM） reveals that the CZNL exhibits agglomerated spherical *** energy dispersive X-ray spectrameter（EDAX） analysis was employed to confirm the elemental composition of CZNL *** the process entails the substitution of Fe3+magnetic ions with nonmagnetic ions la3+,the magnetic parameters of CZNL nanoferrites show a general decreasing trend as *** 20 k,saturation magnetization Ms shows an overall drop in its values from 59.302 emu/g at x=0.0-41.295 emu/g at x=0.1,the smallest value of 37.87 emu/g is recorded at x=*** highest coercivity（Hc=125.9 Oe） and remanence（Mr=13.32 emu/g） are recorded for x=0.08 and x=0.04 nanoferrite,*** band gap of all the CZNL nanoferrites was determined using the kubelka-Munk function and Tauc plot for direct permitted *** doping modifies the band gap（within 1.86-1.75 eV）,increases light absorption,induces efficient e/h separation and charge migration to *** nanoferrite Cu0.5Zn0.25Ni0.25la0.06Fe1.94O4achieves a degradation efficiency of 97.3% for methylene blue（MB） dye removal after just 60 *** five recycling processes,the nanoc

关键词： Copper-zinc-nickel Ferrite Photocatalytic properties Rare earths Wastewater treatment

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

studies of two lanthanide coordination polymers built up from dinuclear units

引用

Journal of Rare Earths 2013年第1期31卷 85-93页

作者： B.Benmerad k.Aliouane N.Rahahlia A.Guehria-ladoudi s.Dahaoui C.Lecomte laboratory of Crystallography and Thermodynamic Department of Chemistry Faculty of ScienceUniversity A. MIRABejaa CRM2 UMR-CNRS 7036Institut Jean BarriolUniversity Nancy I

The two three-dimensional oxo-bfidged lanthanides {[Ln2（C4H2O4）3（H20）4]· 3H2O}3, with Ln=Ho3＋（1）; Gd3＋（2）, are isomorphous. They have layer-type structures built up from non-centrosymrnetric dinuclear unit Ln2O12（H2O）4, beside three lattice H20 molecules stabilizing the 3D open-frmnework. The building entities are linked through one classical syn-anti g2-carboxylato-k1O：k^1O＇ bridge. Within the bi-polyhedra, two double μ2-O＇; k2O,O＇ bridges and a syn-syn classical one, support the magnetic measurements carried out on holmium compound indicating relatively weak anti-ferromagnetic interactions. The compari- son with magnetic studies on the almost similar reported Gd（III） compound, suggested that concomitant antiferromagnetic and ferro- magnetic properties could not be excluded. The two distinct thermal behaviors evidenced the higher metal-water bond strength with the smaller cation, and revealed the great supramolecular effects generated by hydrogen-bonding patterns.

关键词： lanthanide organic frameworks crystal structure thermal behavior magnetic interactions 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

A porous puckered V_(2)O_(5) polymorph as new high performance cathode material for aqueous rechargeable zinc batteries

引用

Journal of Energy Chemistry 2021年第10期30卷 459-468,I0012页

作者： Dauren Batyrbekuly Barbara laïk Jean-Pierre Pereira-Ramos Zhumabay Bakenov Rita Baddour-Hadjean Institut de Chimie et des Matériaux Paris Est(ICMPE) UMR 7182 CNRS et UniversitéParis Est Créteil2 rue Henri Dunant94320 ThiaisFrance school of Engineering National Laboratory AstanaNazarbayev University53 Kabanbay Batyr AvenueAstana 010000Kazakhstan

Aqueous rechargeable zinc batteries are getting increasing attention for large-scale energy storage owing to their advantages in terms of cost,environmental friendliness and ***,the layered puckeredγ’-V_(2)O_(5) polymorph with a porous morphology is firstly introduced as cathode for an aqueous zinc battery system in a binary Zn^(2+)/Li^(+)*** Zn‖γ’-V_(2)O_(5) cell delivers high capacities of 240 and190 mAh g^(-1) at current densities of 29 and 147 mA g^(-1),respectively,and remarkable cycling stability in the 1.6 V-0.7 V voltage window(97%retention after 100 cycles at 0.15 A g^(-1)).The detailed structural evolution during first discharge-charge and subsequent cycling is investigated using X-ray diffraction and Raman *** demonstrate a reaction mechanism based on a selective Li insertion in the1.6 V-1.0 V voltage *** involves a reversible exchange of 0.8 Li^(+)in γ’-V_(2)O_(5) and the same structural response as the one reported in lithiated organic ***,in the extended 1.6 V-0.7 V voltage range,this work puts forward a concomitant and gradual phase transformation from γ’-V_(2)O_(5) to zinc pyrovanadate Zn_(3)V_(2)O_(7)(OH)2.2 H_(2)O(ZVO)during *** mechanism involving the in-situ formation of ZVO,known as an efficient Zn and Li intercalation material,explains the high electrochemical performance here reported for the Zn‖γ’-V_(2)O_(5) *** work highlights the peculiar layered-puckeredγ’-V_(2)O_(5) polymorph outperforms the conventionalα-V_(2)O_(5) with a huge improvement of capacity of 240 mAh g^(-1)vs 80 mAh g^(-1) in the same electrolyte and voltage window.

关键词： Vanadium pentoxide γ-V_(2)O_(5) Cathode Aqueous zinc battery High performance layered structure Energy storage Renewable energy

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

Near-Wall Flow in the Blade Cascades Representing last Rotor Root sections of large Output steam Turbines

引用

Journal of Thermal science 2021年第1期30卷 220-230页

作者： ŠIMURDA David FÜRsT Jiří HÁla Jindřich LUXA Martin BOBČÍk Marek NOVÁk Ondřej sYNÁČJaroslav Institute of Thermomechanics of the Czech Academy of sciences Prague 18200Czech Republic Dpt.of Technical Mathematics Faculty of Mechanical EngineeringCTU in PraguePrague 12000Czech Republic Doosan skoda Power Pilsen 30100Czech Republic

This paper investigates the flow past two variants of root section profile cascades for a last stage rotor considering three-dimensional flow structures in the near-wall *** were drawn based on RANs numerical simulations of both variants and on the experimental data obtained by the 3 D traversing in the exit flow field of one of the *** of 3 D structures at two different regimes and its influence on aerodynamic characteristics of the blade cascades was *** distributions of Mach number along the profiles were compared with 2 D optical measurements and its distortion due to the presence of the sidewall was *** interaction between main vortical structures was described and its influence on the loading of the blades,mechanical energy losses and exit flow angle was *** results showed that for a front loaded blade the vortical structures appeared earlier and at a larger extent than for an aft loaded ***,due to different Mach number distribution,contribution of end wall flow to the energy losses was lower in the case of the aft loaded *** influence of the near wall flow on the loading was found to be rather weak while the deviation of the exit flow angle appeared to be comparable for both of the variants.

关键词： turbine blade cascade secondary flow near wall flow supersonic flow CFD experiment

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

Dielectric, piezoelectric, and ferroelectric properties of lanthanum-modified PZTFN ceramics

引用

International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 1019-1027页

作者： Arvind kumar s.k.Mishra Research and Technology Development Centre Sharda University Dr. Harisingh Gour University

specimens of Pb1-1.5xlax（Zr0.53 Ti0.47）1-y-zFeyNb2O3 （x = 0, 0.004, 0.008, 0.012, and 0.016, y = z = 0.01）（PZTFN） ceramics were synthesized by a semi-wet route. In the present study, the effect of la doping was investigated on the structural, microstructural, dielectric, piezoelectric, and ferroelectric properties of the ceramics. The results show that, the tetragonal （space group P4mm） and rhombohedral （space group R3c） phases are observed to coexist in the sample at x = 0.012. Microstructural investigations of all the samples reveal that la doping inhibits grain growth. Doping of la into PZTFN improves the dielectric, ferroelectric, and piezoelectric properties of the ceramics. The hys- teresis loops of all specimens exhibit nonlinear behavior. The dielectric, piezoelectric and ferroelectric properties show a maximum response atx 〉 0.012, which corresponds to the morphotropic phase boundary （MPB）.

关键词： ceramics lanthanum doping dielectric properties piezoelectricity ferroelectricity Rietveld refinement hysteresis loops

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

survival of some food-borne bacteria in kefir produced by microbial levan and pullulan

引用

Food Bioscience 2022年第3期47卷 1082-1089页

作者： Gökhan Gurur Gökmen Jaroslaw kowalik Duygu kışla Department of Food Engineering Faculty of EngineeringEge University35100BornovaIzmirTurkey Department of Dairy science and Quality Management Faculty of Food SciencesUniversity of Warmia and Mazury in OlsztynOczapowskiego str.710-719OlsztynPoland

kefir is a fermented milk product produced by kefir grains traditionally or lyophilized starter *** quality characteristics of kefir produced at 22℃ and 30℃ using kefir grains after addition of microbial levan and pullulan were investigated for 14 ***,the survival of different Gram-positive and Gram-negative bacteria strains which were inoculated before and after fermentation were investigated during *** pH and titratable acidity were in the ranges of 4.67–4.39 and 1.10–0.87%,*** highest exopolysaccharide values(458.3–465.3 mg/kg)were found in the samples produced with the addition of 1%(w/v)of microbial levan at 30℃.Yeast counts were in the ranges of 6.73–5.11 log CFU/mL while the lactobacilli and lactic streptococci counts were in the ranges of 9.64–7.91 and 9.64–8.69 log CFU/mL,*** microbial polysaccharide addition did not show any significant differences in the enumeration of lactic acid bacteria in kefir(p>0.05).All Gram-positive and Gram-negative bacteria grew/survived during fermentation however Listeria monocytogenes was the most susceptible test bacterium to metabolites during *** highest reduction in the counts of *** was determined as 2.39 log units after 24 h of fermentation at 30℃ in the samples which were inoculated before fermentation and produced with the addition of *** samples produced at 30℃ without polysaccharide addition were considered as the best with respect to appearance,taste,consistency and overall acceptability.

关键词： kefir grain Levan Pullulan Food-borne bacteria

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

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：