检索结果-南通市图书馆

Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAd-7) functionalized with d_(2)EHPA

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

Journal of Rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： P.A.Martínez-Montoya R.G.Sanchez-Alvarado d.Y.Medina-Velazquez M.L.Carrera-Jota P.Garnica-chávez A.de J.Morales-Ramirez Higher School of chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for Research and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(d2EHPA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAd-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/L Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/L)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% d_(2)EHPA functionalized resin,pH=1.5 and an S/L ratio of 10 mg/mL The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/L [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery Rare earth solid-liquid extraction XAd-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

Ballistic design and testing of a composite armour reinforced by CNTs suitable for armoured vehicles

在线全文

学校读者我要写书评

暂无评论

defence Technology（防务技术） 2024年第2期32卷 173-195页

作者： Evangelos ch.Tsirogiannis Evangelos daskalakis Mohamed H.Hassan Abdalla M.Omar Paulo Bartolo EOdH SA Research and Development DepartmentLakkoma Chalkidikis63080Greece School of Mechanical Aerospace and Civil EngineeringUniversity of ManchesterManchesterM139PLUK Singapore Centre for 3d Printing School of Mechanical and Aerospace EngineeringNanyang Technological University639798Singapore

This paper is investigating the use of composite armour reinforced by nanomaterials, for the protection of light armoured(LAV) and medium armoured military vehicles(MAV), and the interaction between the composite materials and high-performance ballistic projectiles. Four armour materials, consisted of front hybrid fibre reinforced polymer cover layer, ceramic strike-face, fibre reinforced polymer intermediate layer and the metal matrix composite reinforced backplate, were manufactured and assembled by adhesive technology. The proposed laminated protection system is suitable for armoured ground vehicles;however, it could be used as armour on ground, air and naval platforms. The design of the protection system, including material selection and thickness, was elaborated depending on the performance requirements of Level 4 + STANAG 4569 military standard(projectile 14.5 mm × 114 mm API B32) and especially on a design philosophy which is analysed with the specifications. The backplate of this new composite is a hybrid material of Metal Matrix Composite(MMC) reinforced with carbon nanotubes(CNTs), manufactured with the use of powder metallurgy technique. The composite backplate material was morphologically, mechanically and chemically analysed. Results show that all plates are presenting high mechanical properties and ballistic characteristics, compared to commonly used armour plates. Real military ballistic tests according to AEP-STANAG 4569 were carried out for the total composite armour systems. After the ballistic tests, AA2024-CNT3 showed the best protection results, compared with the other plates(AA2024-CNT1 and AA2024-CNT2), with the projectile being unable to fully penetrate the composite plate.

关键词： Passive armour protection Protective armour Ballistic performance Hybrid composites Vehicle protection

Microbial electricity-driven anaerobic phenol degradation in bioelectrochemical systems

在线全文

学校读者我要写书评

暂无评论

Environmental Science and Ecotechnology 2024年第1期17卷 40-47页

作者： Shixiang dai Falk Harnisch Micjel chávez Morejòn Nina Sophie Keller Benjamin Korth Carsten Vogt department of Environmental Microbiology Helmholtz Centre for Environmental Research GmbH-UFZLeipzigGermany department of Isotope Biogeochemistry Helmholtz Centre for Environmental Research GmbH-UFZLeipzigGermany

Microbial electrochemical technologies have been extensively employed for phenol ***,previous research has yielded inconsistent results,leaving uncertainties regarding the feasibility of phenol degradation under strictly anaerobic conditions using anodes as sole terminal electron *** this study,we employed high-performance liquid chromatography and gas chromatography-mass spectrometry to investigate the anaerobic phenol degradation *** findings provide robust evidence for the purely anaerobic degradation of phenol,as we identified benzoic acid,4-hydroxybenzoic acid,glutaric acid,and other metabolites of this ***,no typical intermediates of the aerobic phenol degradation pathway were ***-chamber reactors(t0.4 V ***)exhibited a phenol removal rate of 3.5±0.2 mg L^(-1) d^(-1),while two-chamber reactors showed 3.6±0.1 and 2.6±0.9 mg L^(-1) d^(-1) at anode potentials of t0.4 and t 0.2 V,*** results also suggest that the reactor configuration certainly influenced the microbial community,presumably leading to different ratios of phenol consumers and microorganisms feeding on degradation products.

关键词： Microbial electroremediation Geobacter Extracellular electron transfer Anaerobic phenol degradation Microbial syntrophy

Highly divergent sympatric lineages of Leptotila verreauxi(Aves:Columbidae)suggest a secondary contact area in the Isthmus of Tehuantepec,Mexico

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

Avian Research 2024年第1期15卷 12-21页

作者： Orlando J.Espinosa-chávez Adolfo G.Navarro-Sigüenza Hernando Rodríguez-Correa Luis A.Sánchez-González Museo de Zoología“Alfonso L.Herrera” Depto.de Biología EvolutivaFacultad de CienciasUniversidad Nacional Autonoma de MexicoApdo.Postal 70-399CP 04510Ciudad de MexicoMexico Posgrado en Ciencias Biologicas Unidad de PosgradoEdificio D1◦PisoCircuito de PosgradosCiudad UniversitariaUniversidad Nacional Autonoma de MexicoCoyoacanCP 04510CDMXMexico Escuela Nacional de Estudios Superiores Unidad Morelia Universidad Nacional Autonoma de Mexico.Antigua Carretera a Patzcuaro No.8701 Col.Ex Hacienda de San Jose de la HuertaC.P.58190MoreliaMichoacanMexico

due to a complex geological and biotic history,the Isthmus of Tehuantepec(IT),has been long recognized as a driver for the evolutionary divergence of numerous lowland and highland *** distributed in the lowlands of the American continent,the White-Tipped dove(Leptotila verreauxi)is a polytypic species with 13 recognized *** of these have been recorded in Mexico,and the distribution of three abuts at the IT,suggesting a contact *** estimate phylogenetic patterns,divergence times and genetic differentiation,we examined two mt dNA(Nd2 and COI)and one n dNA(β-fibint 7)*** also used correlative ecological niche models(ENM)to assess whether ecological differences across the IT may have acted as a biogeographical *** estimated paleodistributions during the Middle Holocene,Last Glacial Maximum and Last Interglacial,to evaluate the influence of climate changes on the distribution and demographic *** results showed genetically distinct lineages that diverged approximately 2.5 million years *** and ecological factors may have played a dual role in promoting differentiation,but also in the formation of a secondary contact zone in the southern *** ecological niche comparisons indicated that the ecological niche of sympatric lineages at the IT are not identical,suggesting niches divergence;in addition,environmental niche models across the region indicated no abrupt biogeographic barriers,but the presence of regions with low *** results suggest that genetic differentiation originated by a vicariant event probably related to environmental factors,favored the evolution of different ecological ***,the absence of a biogeographic barrier but the presence of less suitable areas in the contact regions,suggest that secondary contact zones may be also maintained by climatic factors for the eastern group,but also by biotic interactions for the western group.

关键词： Biogeographical boundary Humid and dry forests Isthmus of Tehuantepec Phylogeography Secondary contact

Olefin Polymerization Behavior of Titanium(IV) Complexes with Fluorinated and Non-fluorinated Aliphatic Phenoxyimine Ligands

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Polymer Science 2024年第1期42卷 52-62,I0007页

作者： Vladislav A.Tuskaev Kasim F.Magomedov Svetlana ch.Gagieva dmitry A.Kurmaev Yulia V.Nelyubina Evgenii K.Golubev Maria d.Evseeva Viktor G.Vasil'ev Galina G.Nikiforova Mikhail I.Buzin Vyacheslav S.Bogdanov Boris M.Bulychev department of chemistry M.V.Lomonosov Moscow State UniversityMoscow 119992Russian Federation A.N.Nesmeyanov Institute of Organoelement Compounds Russian Academy of SciencesMoscow119991Russian Federation Enikolopov Institute of Synthetic Polymer Materials Russian Academy of SciencesMoscow 117393Russian Federation

A series of Ti(Ⅳ) dichloride and dialkoxide com plexes with phenoxyimine ligands containing fluorinated and nonfluorinated aliphatic imine fragments have been *** molecular structures of complexes 1 and 4 were established by single-crystal X-ray diffraction *** complexes adopt a distorted octahedral coordination structure around the titanium atom and two oxygen atoms are situated in trans position while two nitrogen atoms and two outgoing ligands(Cl or iPrO) are situated in cis *** of activators(MMAO-12 and combinations Et_nAICl_(3-n)+Bu_(2)Mg) and outgoing ligand(Cl or iPrO) nature on the catalytic activity and properties of the resulting polymers was *** Ti complexes,despite the nature of the outgoing ligands(Cl or iPrO) in the presence of Al/Mg activators,was found to display a high ethylene polymerization activity in the range 1600-3830 kg_(polymer)·mol_(Ti)^(-1)·h^(-1)·atm^(-1) with a viscosity average molecular weight(M_v) value in the range 1.1×10~6-7.1×10~6 dalton(da).The resulting UHMWPE can be processed by a solventless method into high-strength and high-modulus oriented *** rheological characteristics of a polymer melt have been *** absence of a cross-over point did not allow to compare the values of the molecular weight distribution of polymers obtained on fluorinated and non-fluorinated pre-catalysts,however,the estimation of the entanglement density is in good agreement with the mechanical characteristics of oriented film *** activation with methylalumoxane,the activity of the com plexes decreased very significantly;however,a polymer with a molecular weight of about 12 million da was *** the process of ethylene/octene-1 copolymerization,fluorine-containing precatalysts showed a clear advantage over non-fluorinated analogues both in activity and in comonomer content.

关键词： FI catalysts Titanium(IV) (Co)polymerization Al/Mg co-catalyst Ultra-high molecular weight polyethylene

Carbene chemistry for unnatural biosynthesis

在线全文

学校读者我要写书评

暂无评论

Science china(Life Sciences) 2024年第1期67卷 204-207页

作者： Jing Huang Jay d.Keasling department of chemical and Biomolecular Engineering University of CaliforniaBerkeley 94720USA Joint BioEnergy Institute Lawrence Berkeley National LaboratoryEmeryville 94608USA Biological Systems and Engineering division Lawrence Berkeley National LaboratoryBerkeley 94720USA Novo Nordisk Foundation Center for Biosustainability Technical University of DenmarkKongens Lyngby 2800Denmark department of Bioengineering University of CaliforniaBerkeley 94720USA Synthetic Biochemistry Center Institute for Synthetic BiologyShenzhen Institutes for Advanced TechnologiesShenzhen 518055China

Previously,chemists working in synthesis were jealous of biologists since the enzymes found in nature usually exhibited great catalytic properties(e.g.,high catalytic efficiency,excellent selectivity such as substrate selectivity,regioselectivity and stereoselectivity).However,biological systems lack many counterparts of reactions widely used in chemical synthesis.

关键词： synthesis selectivity catalytic

Ammonia and greenhouse gas distribution in a dairy barn during warm periods

在线全文

学校读者我要写书评

暂无评论

Frontiers of Agricultural Science and Engineering 2024年第3期11卷 428-441页

作者： Provvidenza Rita d’URSO Claudia ARCIdIACONO Giovanni CASCONE department of Agriculture Food and EnvironmentUniversity of CataniaVia S.Sofia n.100Catania 95123Italy

This research aimed to quantify concentrations of ammonia(NH3),carbon dioxide(CO_(2))and methane(ch_(4)),estimate emissions,and analyze the factors influencing them during warm periods in an open dairy barn equipped with two cooling systems in a Mediterranean climate *** distribution within the barn was observed to vary both vertically and horizontally,with the highest gas concentrations observed in the central area of the ***_(3),ch_(4)and CO_(2)ranged in 1.7–7.4,7–18,560–724μg·g^(–1),*** ventilation through openings and the operation of cooling systems induced changes in indoor microclimate conditions,influencing cow behavior and,consequently,gas *** concentrations were the highest at air velocities below 0.5 m·s^(–1).The highest concentration of NH_(3)was observed when the temperature-humidity index(THI)was>72 and≤78;and CO_(2)and ch_(4)concentrations were the highest with THI≥72 and decreased with THI≤***_(3)concentrations when barn management included three daily milkings were higher than those measured when barn management was based on two daily milkings,and lower for ch_(4)and CO_(2).NH_(3)and ch_(4)emissions were the highest during barn cleaning,while the lowest NH_(3)emissions occurred during activity of the cows(i.e.,feeding,walking).

关键词： Ammonia greenhouse gas environmental monitoring cows’behavior barn management housing system climatic parameters

Solar-driven CO_(2) conversion to methane and methanol using different nanostructured Cu_(2)O-based catalysts modified with Au nanoparticles

在线全文

学校读者我要写书评

暂无评论

Journal of Energy chemistry 2024年第4期91卷 287-298页

作者： João Angelo Lima Perini Lilian d.Moura Torquato Juliana Fde Brito Gustavo A.Andolpho Mateus A.Gonçalves Leonardo d.de Angelis Lucas d.Germano Susana I.Córdoba de Torresi Teodorico C.Ramalho Maria V.Boldrin Zanoni São Paulo State University(UNESP) Institute of ChemistryRua Prof.Francisco Degni55AraraquaraSP 14800-060Brazil National Institute of Alternative Technologies for detection Toxicological Evaluation and Removal of Micropollutants and Radioactive Substances(INCT-DATREM)São Paulo State University(UNESP)Institute of ChemistryRua Prof.Francisco Degni55AraraquaraSP 14800-060Brazil Laboratory of Molecular Modelling Department of ChemistryNatural Sciences InstituteFederal University of LavrasLavrasMG 37200-900Brazil department of chemistry Faculty of ScienceUniversity of Hradec KrálovéHradec Králové50003Czech Republic Instituto de Química Universidade de São PauloAv.Prof.Lineu Prestes 74805508-080São PauloSPBrazil

This work describes the use of TiO_(2)nanotubes-based electrodes(TNT)modified with Cu_(2)O nanostructures and gold nanoparticles for the photoelectroreduction of CO_(2)to produce value-added compounds.A thin layer of polydopamine was used as both an adherent agent and an electron transfer mediator,due to itsπ-conjugated electron *** highest production yield was achieved using a TNT@PdA/Nc/Au40%electrode,with Faradaic efficiencies of 47.4%(110.5μM cm^(-2))and 27.8%(50.4μM cm^(-2))for methanol and methane,*** performance of the photoelectrodes was shown to be Cu_(2)O facet-dependent,with cubic structures leading to greater conversion of CO_(2)to methanol(43%)and methane(27%),compared to the octahedral morphology,while a higher percentage of metallic gold on the nanostructured Cu_(2)O surface was mainly important for *** functional theory(dFT)calculations supported these findings,attributing the superior photoelectrocatalytic performance of the TNT@PdA/Nc/Au40%electrode for ch4generation to the formation of an Och3intermediate bonded to Au *** using isotope-labeling and analysis by gas chromatograph-mass(GC-MS)demonstrated that13CO_(2)was the source for photoelectrocatalytic generation of13ch3OH and13ch313ch2OH.

关键词： Cu_(2)O nanocubes Photoelectrocatalysis Polydopamine CO_(2) photoelectroreduction dFT calculations

Effect of spark plasma sintering and reinforcements on the formation of ultra-fine and nanograins in AA2024-TiB2-Y hybrid composites

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2022年第1期32卷 79-86页

作者： ch.Suresh Vidyasagar d.B.Karunakar department of Architecture and Planning Indian Institute of Technology Roorkee Mechanical and Industrial Engineering department Indian Institute of Technology Roorkee

This study reports the influence of sintering mechanism and reinforcement materials on the formation of ultra-fine and nanograins in Al-TiB-Y nanohybrid composites. The mechanical properties of the composites and their corresponding micro and nanostructures are correlated. The experimental and characterization results revealed that despite the addition of TiB, the hard and brittle AlTi phase formation in the composites was suppressed and hence, their ductility was retained. It was found that yttrium content of 0.3 wt% was the optimum amount which created advantageous spark plasma sintering conditions, and the addition of 0.3 wt% promoted the formation of bi-modal size grains（ultra-fine and nano） along with micro grains, Ω and other nano precipitates, resulting in a significant enhancement in the composite properties. The formation of ultra-fine and nanograins may be attributed to the combined effect of melting and rapid solidification at necking zones due to Joule’s heating and thermomechanical fatigue. Among all the sintered composites, the highest hardness（137 HV）, ultimate tensile strength（UTS）(496 MPa), yield strength（YS）(438 MPa) with 15.7% elongation were obtained in the sintered sample reinforced with 1.0 wt% TiBand 0.3 wt% yttrium.

关键词： Hybrid composites Ultra-fine grains Nano grains Spark plasma sintering Nano precipitates Microstructure