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Influence of cerium ions on structure-dependent magnetic properties of Ba-Sr m-type hexaferrite nanocrystals

Journal of Rare Earths 2024年第2期42卷 364-372,I0005页

作者： Ram A.pawar Sunil m.patange p.m.Dighe Sher Singh meena Abdullah GAl-Sehemi mehboobali pannipara Santosh S.Jadhav Department of physics ArtsCommerce and Science CollegeAhmednagar413711MaharashtraIndia Department of physics Shri Krishna MahavidyalayaGunjotiDistOsmanabad413606MaharashtraIndia padmashri Vikhe patil College of Arts Science and CommercePravaranagarA/P.Loni(Kd)Tal.RahataDistAhmednagar413713MaharashtraIndia Solid State physics Division Bhabha Atomic Research CentreMumbai400085MaharashtraIndia Department of Chemistry King Khalid UniversityAbha61413Saudi Arabia Department of physics D.S.M's ArtsCommerce and Science CollegeJintur431509MaharashtraIndia

The present study is a systematic effort to investigate the structure-sensitive magnetic parameters of Ce^(3+) substituted Ba-Sr hexaferrite nanocrystals chemically formulated as Ba_(0.5)Sr_(0.5)Ce_(x)Fe_(12-x)O_(19) where x=0.0-0.2 with Δx=*** hexaferrite powders were prepared using the sol-gel self-ignition route and structurally characterized by means of powder X-ray diffraction and Fourier transform infrared *** creation of the m-type hexaferrite phase within the synthesized samples was revealed from the Rietveld refinement of the X-ray *** occurrence of a secondary phase of CeO_(2) was revealed within the hexaferrites for the substitution,x> *** refined X-ray diffraction data were utilized to compute the lattice parameters,X-ray density,and lattice parameter *** crystal structure plotted from the refined XRD data reveals the occupancy of the ions at different lattice *** XpS data of the hexaferrite were analyzed to confirm the oxidation states of the constituent *** nanocrystalline nature of the hexaferrites was revealed from the crystallite sizes calculated using Scherer's *** analysis of FTIR spectra confirms that only a fraction of Ce^(3+)accommodated in the lattice and the remaining Ce content reside in the form of the CeO_(2) *** morphology of the hexaferrites was analyzed from the FESEm profiles of the ferrite *** magnetic behavior study was performed by analyzing the Curie temperature,hysteresis loops,and hyperfine interactions by means of susceptibility,V.S.m,and mossbauer spectroscopy,*** hexaferrites with increasing coercivity,decreasing saturation magnetization,and decreasing Curie temperature are reported in the *** substituted Ce^(3+)ions inhibit the grain growth and create lattice imperfections giving rise to hexaferrites with tuned magnetic parameters suitable for different applications.

关键词： Ba-Sr hexaferrite Ce^(3+)substitution XpS Saturation magnetization Coercivity m?ssbauer spectroscopy

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旧金山不含IS6110结核分支杆菌菌株的流行病学

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国际结核病与肺部疾病杂志 1998年第2期 52-54页

作者： C.B.Agasino A.poncedeLeon R.m.Jasmer p.m.small 何广学 Division of Infectious Disease and Geographic medicine Department of MedicineStanford University School of Medicine Division of pulmonary and Critical Care medicine Department of MedicineUniversity of CaliforniaSan FranciscoCAUSA

IS6110通常作为结核分支杆菌的分子流行病学和诊断研究的基础,然而,不含IS6110的菌株已有报道。如果这种菌株常见,将使结核分支杆菌的分子研究受到限制。对来自旧金山的一个人群样本的1569份标本进行指纹分析显示:不含IS6110的菌株的比... 详细信息

IS6110通常作为结核分支杆菌的分子流行病学和诊断研究的基础,然而,不含IS6110的菌株已有报道。如果这种菌株常见,将使结核分支杆菌的分子研究受到限制。对来自旧金山的一个人群样本的1569份标本进行指纹分析显示:不含IS6110的菌株的比例低于1％,由于这种比例低,在旧金山可以进行IS6110指纹分析,而在其它地方可能存在问题。

关键词： IS6110 RFLp pGRS 结核病分子流行病学分子诊断学

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Intertype superconductivity evoked by the interplay of disorder and multiple bands

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Frontiers of physics 2024年第4期19卷 81-89页

作者： p.m.marychev A.A.Shanenko A.V.Vagov HSE University 101000 MoscowRussia Center for Advanced mesoscience and Nanotechnology MIPTDolgoprudny141700Russia

Nonmagnetic impurity scattering is known to shift up the Ginzburg-Landau parameter k of a *** this case,when the system is initially in type I,it can change its magnetic response,crossing the intertype domain with k~1 between the two standard superconductivity types and arriving at type *** the present work we demonstrate that the impact of disorder can be much more profound in the presence of the multiband structure of the charge carrier *** particular,when the band diffusivities differ from each other,the intertype domain tends to expand significantly,including points with k>1 that belong to deep type-Ⅱ in conventional single-band *** finding sheds light on the nontrivial disorder effect and significantly complements earlier results on the enlargement of the intertype domain in clean multiband superconductors.

关键词： superconductivity disorder intertype superconductivity twoband model

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mechanisms behind the environmental sensitivity of carbon fiber reinforced polytetrafluoroethylene(pTFE)

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Friction 2024年第5期12卷 997-1015页

作者： pontus JOHANSSON p.mARKLUND m.BJORLING Y.SHI Division of machine Element LuleåUniversity of TechnologyLuleåSE-97187Sweden

Carbon fiber reinforced polytetrafluoroethylene (CF/pTFE) composites are known for their exceptional tribological performance when sliding against steel or cast iron in inert gas environments. Compared to experiments in humid air, about an order of magnitude lower wear rate and several times lower coefficient of friction have been reported for tests conducted in dry nitrogen and hydrogen. moreover, trace moisture has been shown to affect the friction and wear significantly of this tribosystem, although a possible effect of oxygen cannot be ruled out due to uncertainties regarding the oxygen concentrations. While several studies have pointed out the environmental sensitivity of CF/pTFE, the understanding of the underlying mechanisms are very limited. The objective of this research is to investigate the individual and combined effect of oxygen and moisture on the tribological behavior of CF/pTFE sliding against steel. Additionally, this study aims to elucidate the underlying mechanisms that govern the environmental sensitivity of the system. Climate-controlled three-pin-on-disc experiments were conducted in nitrogen atmospheres at various concentrations of oxygen and moisture. The tribological results clearly demonstrate that both moisture and oxygen contribute to increased friction and wear. However, the adverse effect was much more pronounced for oxygen than moisture. A qualitative method was developed to estimate the tribofilm coverage on the CF/pTFE surface. Results showed strong correlation between high coverage of strongly adhered tribofilm and low wear rate. moreover, a loosely adhered tribofilm was observed on top of the CF/pTFE surface in presence of moisture. FTIR analysis indicated that the loosely adhered tribofilm found in the moisture-enriched environment contained a significant amount of adsorbed water, which may explain the lower coefficient of friction in presence of moisture compared to oxygen. The adsorbed water in the loosely adhered tribofilm coul

关键词： polymer composite tribofilm tribochemistry atmosphere

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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 Ecosystems 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 UmR 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 coming decades in Western Europe may disturb forest biogeochemical 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 maintenance of tree nutrition are poorly *** experiment in a beech forest in meuse(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 dynamics,including resorption,chemistry of green and senesced leaves,foliar absorption and leaching in mature beech stands from 2012 to 2019 allowed us to compare 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 almost 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 coming decades,there will be a risk of potassium deficiency in trees,as already observed in a rainfall exclusion experiment on the same 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 more likely to improve 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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RNA m^(6)A reader YTHDF2 facilitates precursor miR-126 maturation to promote acute myeloid leukemia progression

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Genes & Diseases 2024年第1期11卷 382-396页

作者： Zheng Zhang Keren Zhou Li Han Andrew small Jianhuang Xue Huilin Huang Hengyou Weng Rui Su Brandon Tan Chao Shen Wei Li Zhicong Zhao Ying Qing Xi Qin Kitty Wang Keith Leung mark Boldin Chun-Wei Chen David Ann Zhijian Qian Xiaolan Deng Jianjun Chen Zhenhua Chen Department of Systems Biology Beckman Research Institute of City of HopeMonroviaCA 91016USA Irell and manella Graduate School of Biological Sciences Beckman Research Institute of City of HopeDuarteCA 91010USA Gehr Family Center for Leukemia Research City of HopeDuarteCA 91010USA Sun Yat-sen University Cancer Center State Key Laboratory of Oncology in South ChinaCollaborative Innovation Center for Cancer MedicineGuangzhouGuangdong 510060China Guangzhou Laboratory GuangzhouGuangdong 510005China Bioland Laboratory GuangzhouGuangdong 51005China Department of Liver Surgery Renji HospitalShanghai Jiao Tong University School of MedicineShanghai 200127China Department of Diabetes Complications and metabolism Beckman Research Institute of City of HopeDuarteCA 91010USA Department of Biochemistry and molecular Biology University of FloridaGainesvilleFL 32603USA Tongji Hospital Affiliated to Tongji University Frontier Science Center for Stem Cell ResearchSchool of Life Sciences and TechnologyTongji UniversityShanghai 200092China School of pharmacy China Medical UniversityShenyangLiaoning 110001China

As the most common internal modification of mRNA,Ne-methyladenosine(m^(6)A)and its regulators modulate gene expression and play critical roles in various biological and patholog-ical processes including *** was reported previously that m^(6)A methyltransferase(writer),methyltransferase-like 3(mETTL3)adds m^(6)A in primary microRNAs(pri-miRNAs)and fa-cilitates its processing into precursor miRNAs(pre-miRNAs).However,it is unknown whether m^(6)A modification also plays a role in the maturation process of pre-miRNAs and(if so)whether such a function contributes to ***,we found that YTHDF2 is aberrantly overexpressed in acute myeloid leukemia(AmL)patients,especially in relapsed patients,and plays an onco-genic role in ***,YTHDF2 promotes expression of miR-126-3p(also known as miR-126,as it is the main product of precursor miR-126(pre-miR-126)),a miRNA that was reported as an oncomiRNA in AmL,through facilitating the processing of pre-miR-126 into mature ***,YTHDF2 recognizes m^(6)A modification in pre-miR-126 and recruits AGO2,a regulator of pre-miRNA processing,to promote the maturation of ***2 posi-tively and negatively correlates with miR-126 and miR-126's downstream target genes,respec-tively,in AmL patients,and forced expression of miR-126 could largely rescue YTHDF2/Ythdf2 depletion-mediated suppression on AmL cell growth/proliferation and leukemogenesis,indi-cating that miR-126 is a functionally important target of YTHDF2 in ***,our studies not only reveal a previously unappreciated YTHDF2/miR-126 axis in AmL and highlight the ther-apeutic potential of targeting this axis for AmL treatment,but also suggest that m^(6)A plays a role in pre-miRNA processing that contributes to tumorigenesis.

关键词： AmL miR-126 N^(6)-methyladenosine pre-miRNA maturation YTHDF2

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多种标志物在人群结核病分子流行病学研究中的应用

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国际结核病与肺部疾病杂志 2001年第2期 80-87页

作者： J.T.Rhee m.m.Tanaka m.A.Beh C.B.Agasino E.A.paz p.C.Hopewell p.m.small 吴雪琼 Division of Epidemiology Department of Health Research and Policy Stanford University School of Medicine Stanford California Department of Biological Sciences Stanford University Stanford California Division of Infectious Diseases and microbiology Montreal General Hospital. Montreal Canada Division of Infectious Diseases and Geographic medicine. Department of medicine Stanford University School of Medicine Department of public Health Division of Tuberculosis Control City and county of San Francisco California Francis J. Curry National Tuberculosis Center San Francisco California Division of pulmonary and Critical Care medicine San Francisco General Hospital Medical Center and the Department of Medicine University of California at San Francisco San Francisco California USA

背景:目前世界正在开展很多结核病流行病学研究。对IS6110杂交带少于6条的菌株应用一个二级标志物指纹分析增强了菌株的追踪,但它对人群结论的影响尚未很好地研究。目的:对低拷贝结核分支杆菌菌株应用多态性富含GC重复序列(pGRS)进行... 详细信息

背景:目前世界正在开展很多结核病流行病学研究。对IS6110杂交带少于6条的菌株应用一个二级标志物指纹分析增强了菌株的追踪,但它对人群结论的影响尚未很好地研究。目的:对低拷贝结核分支杆菌菌株应用多态性富含GC重复序列(pGRS)进行二级基因分型。探讨其对以人群为研究背景的流行病学研究结论的影响。设计:对1991—1996年旧金山结核病例,通过单用IS6110及联合采用pGRS/IS6110定义菌株成簇,以便1)估计近期的传播;2)评价细菌群体参数在理论上对这些估计的影响;3)评价近期传播的危险因素。结果:对低拷贝菌株(所有菌株的20.3％)进行二级分型,使近期传播的估算值由29.1％下降到25.3％(p=0.03)。补充基因分型造成不同估算值的最主要的影响参数是低拷贝菌株的比例和成簇的数量。对于上述两种分析方法而言。导致近期传播的危险因素是一样的。结论:结核分支杆菌二级基因分型的统计和推论似乎取决于人群中低拷贝菌株的比例。该比例低时,或没有多少二级特型匹配时,补充基因分型在人群水平研究中的作用可能就很小。

关键词：结核病分子流行病学 IS6110 pGRS

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Tensile deformation of fine-grained mg at 4K,78K and 298K

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Journal of magnesium and Alloys 2024年第6期12卷 2534-2556页

作者： m.Walag A.Kula p.Noga T.Tokarski G.Cios m.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland materials Science and Engineering McMaster UniversityHamiltonCanada

The impact of grain size,ranging from 0.9μm to 9μm,on the mechanical properties of commercially pure mg is investigated at temperatures of 4K,78K,and *** mechanisms governing plastic flow are influenced by both grain size and *** 4K and 78K,dominant deformation modes in mg involve dislocation glide and extension twinning,regardless of grain *** interactions between basal and non-basal dislocations and dislocations with grain boundaries promote an unusually high rate of work hardening in the plastic regime,leading to premature *** yield stress follows the Hall-petch relationshipσ_(y)∼k/√d,with the slope k increasing with decreasing *** 298K,in addition to dislocation glide and twinning,grain boundary sliding(GBS)becomes significant in samples with grain sizes below 3μm,considerably enhancing the material’s *** activation provides an additional recovery mechanism for dislocations accumulating at grain boundaries,facilitating their absorption during sliding and *** ofσrelationship suggests that the basal slip is the dominant dislocation mode in mg at *** grain size suppresses dislocation activity and twinning and increases GBS,resulting in lowerandσ*** conventional deformation modes coupled with enhanced GBS yields stress softening,breaking down the Hall-petch relationship in mg below 3μm grain size,leading to an inverse Hall-petch *** work reports new data on the strength,ductility,work hardening and fracture behaviour,and their variations with mg grain size across different temperature regimes.

关键词： polycrystalline mg mechanical properties Deformation mechanisms Work-hardening Texture evolution Cryogenic temperatures Hall-petch relationship

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Consumer transparency in the production chain for plant varieties produced using new genomic techniques

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aBIOTECH 2024年第2期5卷 239-246页

作者： J.m.Lukasiewicz C.C.m.van de Wiel L.A.p.Lotz m.J.m.Smulders Wageningen University&Research P.O.Box 386NL-6700 AJ WageningenThe Netherlands

plants edited with new genomic techniques(NGTs)currently fall under the Genetically modified Organisms Directive(2001/18/EC)in the European *** the proposal of the European Commission,NGT plants are partially exempted from the regulations of this *** proposal makes a distinction between two categories of NGT plants:NGT-1 and ***-1 category plants are considered equal to plants obtained through conventional breeding *** plants will not be labelled for the consumer,although they will be labelled as ***-2 category plants may be labelled with additional information as a positive *** of seeds of varieties made with gene editing,but not the products,would mean that most steps in the production chain are transparent,but not the last step towards ***“right to know”and increasing knowledge of gene-edited food is a common theme in food labelling towards ***,we describe current labelling regimes and registers and how these may be applied to provide transparency on gene-edited products to ***,we also look into consumer studies,which indicate a greater acceptance of gene-edited food among consumers,especially when additional benefits such as sustainability are mentioned.

关键词： Labelling New genomic techniques Consumer transparency plant products

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Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

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Chinese physics B 2024年第2期33卷 108-114页

作者： U.S.mahabaleshwar G.p.Vanitha L.m.pérez Emad H.Aly I.pop Department of Studies in mathematics Davangere UniversityShivagangothriDavangereIndia Departamento de F´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile Department of mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt Department of mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in H_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/H_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/H_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

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