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multi-exponential model to describe pressure-dependent P-and S-wave velocities and its use to estimate the crack aspect ratio

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Journal of Rock mechanics and Geotechnical Engineering 2022年第2期14卷 385-395页

作者： mihály Dobróka Norbert Péter Szabó tünde Edit Dobróka mátyás Krisztián Baracza Department of Geophysics University of MiskolcMiskolc-Egyetemváros3515Hungary mtA-mE Geoengineering Research Group University of MiskolcMiskolc-Egyetemváros3515Hungary Research Institute of Applied Earth Sciences University of MiskolcMiskolc-Egyetemváros3515Hungary

We present new quantitative model describing the pressure dependence of acoustic P-and S-wave *** that a variety of individual mechanisms or defects(such as cracks,pore collapse and grain crushing)can contribute to the pressure-dependent change of the wave velocity,we order a characteristic pressure to all of them and allow a series of exponential terms in the description of the(Pand S-waves)velocity-pressure *** estimate the parameters of the multi-exponential rock physical model in inversion procedures using laboratory measured P-and S-wave velocity *** is known,the conventional damped least squares method gives acceptable results only when one or two individual mechanisms are *** the number of exponential terms leads to highly nonlinear ill-posed inverse *** to this reason,we develop the spectral inversion method(SIm)in which the velocity amplitudes(the spectral lines in the characteristic pressure spectrum)are only considered as *** characteristic pressures(belonging to the velocity amplitudes)are excluded from the set of inversion unknowns,instead,they are defined in a set of fixed positions equidistantly distributed in the actual interval of the independent variable(pressure).through this novel linear inversion method,we estimate the parameters of the multi-exponential rock physical model using laboratory measured P-and S-wave velocity *** characteristic pressures are related to the closing pressures of cracks which are described by well-known rock mechanical relationships depending on the aspect ratio of elliptical *** gives the possibility to estimate the aspect ratios in terms of the characteristic pressures.

关键词： multi-exponential rock physical model Spectral inversion method(SIm) Crack aspect ratio Characteristic pressures

this work was supported by the European Research Council Advanced Grant(EtAP-742985 to *** J.F.)and by the ministry of Science and technology(grant 110-2636-B-005-001 to K.-J.L.).

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Plant Communications 2024年第1期5卷 130-147页

作者： Yu Zhang Yuan Fu Wenfei Xian Xiuli Li Yong Feng Fengjiao Bu Yan Shi Shiyu Chen Robin van Velzen kai Battenberg Alison m.Berry marco G.Salgado Hui Liu tingshuang Yi Pascale Fournier Nicole Alloisio Petar Pujic Hasna Boubakri m.Eric Schranz Pierre-marc Delaux Gane ka-Shu Wong Valerie Hocher Sergio Svistoonoff Hassen Gherbi Ertao Wang Wouter Kohlen Luis G.Wall martin Parniske katharina Pawlowski Philippe Normand Jeffrey J.Doyle Shifeng Cheng Shenzhen Branch Guangdong Laboratory for Lingnan Modern AgricultureGenome Analysis Laboratory of the Ministry of AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhen 518124China Biosystematics Group Department of Plant SciencesWageningen University6708PB Wageningenthe Netherlands Department of Plant Sciences University of CaliforniaDavisDavisCA 95616USA Department of Ecology Environment and Plant SciencesStockholm University10691 StockholmSweden Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesLanhei RoadKunming 650201China universite´de Lyon Universite´Lyon 1CNRSUMR5557Ecologie MicrobienneINRAUMR 141843 bd du 11 novembre 191869622 VilleurbanneFrance Laboratoire de Recherche en Sciences Ve´ge´tales(LRSV) Universite´de ToulouseCNRSUPS24 chemin de Borde RougeAuzevilleBP4261731326 Castanet TolosanFrance Department of Biological Sciences University of AlbertaEdmontonAB T6G 2E9Canada French National Research Institute for Sustainable Development(IRD) UMR LSTM(IRD/CIRAD/INRAe/Montpellier University/Supagro)-Campus International BaillarguetTA A-82/J34398 Montpellier Cedex 5France National Key Laboratory of Plant molecular Genetics CAS Center for Excellence in Molecular Plant SciencesInstitute of Plant Physiology and EcologySIBSChinese Academy of SciencesShanghaiChina Laboratory of molecular Biology Department of Plant SciencesWageningen University6708PB Wageningenthe Netherlands Laboratory of Biochemistry Microbiology and Soil Biological InteractionsDepartment of Science and TechnologyNational University of QuilmesCONICETBernalArgentina Faculty of Biology GeneticsLMU MunichGroßhaderner Strasse 2-482152 MartinsriedGermany School of Integrative Plant Science Sections of Plant Biology and Plant Breeding&GeneticsCornell UniversityIthacaNY 14853USA State Key Laboratory of Systematic and Evolutionary Botany Institute of BotanyChinese Academy of SciencesBeijing 100093China univer

Plant root-nodule symbiosis(RNS)with mutualistic nitrogen-fixing bacteria is restricted to a single clade of angiosperms,the Nitrogen-Fixing Nodulation Clade(NFNC),and is best understood in the legume *** species share many commonalities,explained either by divergence from a common ancestor over 100 million years ago or by convergence following independent origins over that same time ***,comparative analyses of diverse nodulation syndromes can provide insights into constraints on nodulation—what must be acquired or cannot be lost for a functional symbiosis—and the latitude for Plant Communications Genomic landscape of nodulation variation in the ***,much remains to be learned about nodulation,especially outside of ***,we employed a large-scale phylogenomic analysis across 88 species,complemented by 151 RNA-seq libraries,to elucidate the evolution of *** phylogenomic analyses further emphasize the uniqueness of the transcription factor NIN as a master regulator of nodulation and identify key muta-tions that affect its function across the *** transcriptomic assessment revealed nodule-specific upregulated genes across diverse nodulating plants,while also identifying nodule-specific and nitrogen-response *** 70%of symbiosis-related genes are highly conserved in the four representative species,whereas defense-related and host-range restriction genes tend to be lineage *** study also identified over 900000 conserved non-coding elements(CNEs),over 300000 of which are unique to sampled NFNC ***-specific CNEs are enriched with the active H3K9ac mark and are correlated with accessible chromatin regions,thus representing a pool of candidate regula-tory elements for genes involved in ***,our results provide novel insights into the evolution of nodulation and lay a foundation for engineering of RNS traits in agriculturally important crops.

关键词： nitrogen-fixing root-nodule symbiosis two competing hypotheses phylogenomics phylotranscrip-tomics conserved non-coding elements convergence deep homology

tailoring the optical and magnetic properties of La-Bam hexaferrites by Ni substitution

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Chinese Physics B 2022年第2期31卷 570-575页

作者： Hafiz t.Ali mRamzan m Imran Arshad Nicola A.morley m.Hassan Abbas mohammad Yusuf Atta Ur Rehman Khalid mahmood Adnan Ali Nasir Amin mAjaz-un-Nabi Department of mechanical Engineering College of EngineeringTaif UniversityTaif 21944Saudi Arabia Department of Physics Government College UniversityFaisalabadPakistan Department of materials Science and Engineering University of SheffieldSir Robert Hadfield BuildingMapping St.SheffieldS13JDUK Department of Clinical Pharmacy College of PharmacyTaif UniversityTaif 21944Saudi Arabia

We investigate the impact of Ni insertion on the structural,optical,and magnetic properties of Ba_(0.8)La_(0.2)Fe_(12-x)Ni_(x)O_(19)hexaferrites(Ni substituted La-Bam hexaferrites).Samples were prepared using the conventional co-precipitation method and sintered at 1000℃for 4 hours to assist the crystallization *** analysis of the structure of the samples was carried out using an x-ray diffraction(XRD)*** m-type hexagonal structure of all the samples was confirmed using XRD *** lattice parameters a and c were found to be in the ranges of 5.8925±0.001 nm–5.8952±0.001 nm and 23.2123±0.001 nm–23.2219±0.001 nm,*** m-type hexagonal nature of the prepared samples was also indicated by the presence of corresponding Ft-IR bands and Raman modes in the Ft-IR and Raman spectra,*** results confirmed the successful synthesis of the samples according to the required stoichiometric ratio.A UV-vis spectrometer was used to record the absorption spectra of the prepared samples in the wavelength range of 200 nm–1100 *** optical energy bandgap of the samples was found to be in the range of 1.21 eV–3.39 *** m–H loops of the samples were measured at room temperature at an applied magnetic field range of 0 kOe–60 kOe.A high saturation magnetization of 99.92 emu/g was recorded in the sample with x=0 at a microwave operating frequency of 22.2 *** high value of saturation magnetization is due to the substitution of La3+ions at the spin-up(12k,2a,and 2b)*** Ni substitution is proven to be a potential candidate for the tuning of the optical and magnetic parameters of m-type ***,we suggest that the prepared samples are suitable for use in magneto-optic applications.

关键词： m-type hexaferrite nanostructured materials magnetic properties optical properties

Effectiveness of external prestressing in enhancing the non-ductile hanger failure mechanism in reinforced concrete inverted t-beams

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 1050-1065页

作者： Ahmed m.AttA Reda N.BEHIRY mohammed I.HARAZ Structural Engineering Department Faculty of EngineeringTanta UniversityTanta 33511Egypt Nile Higher Institute for Engineering and technology Mansoura 11001Egypt

Recently,inverted t-beams have been used in reinforced concrete(RC)bridges to support transverse precast *** t-beams,contrary to practice with conventional beams,are loaded on the flanges upper *** loading configuration causes hanger failure due to the generation of vertical tensile stresses near the bottom of the *** key purpose of this study is to investigate the efficiency of vertical external prestressing stainless-steel bars in mitigating non-ductile hanger failure in reinforced concrete inverted *** experimental study on six inverted-t beams,including two un-strengthened specimens,was carried *** study showed that the value of the prestressing level had a considerable impact on the performance of hanger mechanism in relation to crack pattern,ultimate loads,cracking behavior,load-deflection,strains,and *** experimental results indicated that the suggested method for strengthening inverted t-beams had efficacy in reducing the seriousness of the non-ductile hanger failure and resulted in a strength increase of up to 53% when compared to that of the un-strengthened ***,two analytical models for estimating the hanger capacity and the average crack width of the strengthened RC inverted t-beams were *** models that were proposed exhibited a high degree of agreement with the experimental results.

关键词： RC bridges inverted t-beams strengthening hanger failure external prestressing

Effects of varying Alx moles on structure and luminescence properties of ZnAl_(x)O_(1.5x+1):0.1 mol%tb^(3+)nanophosphors prepared using citrate sol-gel method

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Journal of Rare Earths 2023年第3期41卷 358-364,I0002页

作者： V.m.maphiri L.t.melato m.R.mhlongo t.t.Hlatshwayo t.E.motaung L.F.Koao S.V.motloung Department of Physics Sefako Makgatho Health Science UniversityP.O.Box 94Medunsa0204South Africa Department of mathematics Non Destructive Testing and PhysicsVaal University of TechnologyAndries Potgieter BlvdVanderbijlpark1900South Africa Department of Physics University of PretoriaPretoria0002South Africa Department of Chemistry School of Science in the College of Science Engineering and TechnologyUniversity of South AfricaPreller StreetMuckleneuk RidgeCity of TshwaneP.O Box 392UNISA 0003South Africa Department of Chemistry Sefako Makgatho Health Science UniversityP.O.Box 94Medunsa0204South Africa Department of Physics University of the Free State(Qwaqwa Campus)Private Bag X13Phuthaditjhaba 9866South Africa Department of Chemical and Physical Sciences Walter Sisulu UniversityMthathaSouth Africa

un-doped and ZnAl_(x)O_(1.5x+1):0.1 mol%tb^(3+)(ZAOt)nano-powders were synthesized via citrate sol-gel *** AIx moles were varied in the range of 0.25≤x≤*** X-ray powder diffraction(XRD)data reveal that for xthe prepared samples crystal structure consists of mixed phases of the cubic ZnAl_(2)O_(4) and hexagonal ZnO phases,while for x>1.5 the structure consists of single phase of cubic ZnAl_(2)O_(4).the Raman and Fourier-trans form infrared(FtIR)vibrational spectroscopy show the presence of vibrations emanating ZnAl_(2)O_(4) *** electron microscopy(SEm)and transmission electron microscopy(tEm)show the presence of irregular sphere at x>2.0 attributed to ZnAl_(2)O_(4).the photoluminescence(PL)spectroscopy reveals emissions from both the host and tb^(3+)*** from tb^(3+)are observed at 382,414,439,458 nm and 489,545,585,621 nm,which were attributed to the^(5)D_(3)→^(7)F_(6,5,4,2) and ^(5^)D_(4)→^(7)F_(6,5,4,3),*** results confirm that the tb^(3+)occupation site depends on the Alx *** International Commission on Illumination(CIE)colour chromaticity shows that the emission colour can be tuned from blue to green by varying the AIx moles.

关键词： Citrate sol-gel ZnAl_(2)O_(4)/ZnO tb^(3+)-doped Al_(x)moles Photoluminescence Rare earths

Improving high-temperature oxidation behavior by modifying Al and Co content in Al-Co-Cr-Fe-Ni high-entropy alloy

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Journal of materials Science & technology 2022年第34期129卷 115-126页

作者： timothy Alexander Listyawan maya Putri Agus tianingrum Young Sang Na ka Ram Lim Nokeun Park School of materials Science and Engineering Yeungnam University280 Daehak-roGyeongbuk 38541Republic of Korea Advanced metals Division Korea Institute of Materials Science(KIMS)797 ChangwondaeroSeongsan-guChangwonGyeongnam 51508Republic of Korea Institute of materials technology Yeungnam University280 Daehak-roGyeongsanGyeongbuk 38541Republic of Korea

Composition modification was introduced to improve the oxidation resistance by varying Al and excluding Co from the Al-Co-Cr-Fe-Ni system. Since adjusting the composition shifted the valence electron concentration(VEC) of the alloys, the dual-phase structure of the alloys is expected to be more stable. At low temperatures(t the alloys formed mixed oxide products. As oxidation temperature increased,only Cr_(2)O_(3)or Al_(2)O_(3)dominated the alloy’s surface. Compared to equiatomic AlCoCrFeNi(5-Equi), nonequiatomic AlCoCrFeNi(5-B 40) and four-component AlCrFeNi(4-B 2013) had better oxidation resistance due to monocrystalline-Al_(2)O_(3)formation. Besides the role of oxide formation, maintaining BCC and B2phases within the alloys is also beneficial to supporting the stable Cr_(2)O_(3)or Al_(2)O_(3).

关键词： High-entropy alloy Alloy design Oxidation Valence electron concentration Phase stability transmission electron microscope

magnetic Properties of Nd-Fe-B Sintered magnet Powders Recovered by Yb metal Vapor Sorption

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Journal of Rare Earths 2004年第1期22卷 152-156页

作者： Horikawa t Itoh m Suzuki Shunji machida K Collaborative Research Center for Advanced Science and technology Collaborative Research Center for Advanced Science and TechnologyCollaborative Research Center for Advanced Science and TechnologyCollaborative Research Center for Advanced Science and Technology Osaka University Osaka 565-0871 Japan Osaka University Osaka 565-0871 Japan Osaka University Osaka 565-0871 Japan Osaka University Osaka 565-0871 Japan

Fine ground powders of Nd-Fe-B sintered magnet bulks (particle size=46～125 μm in diameter) were coated and alloyed with Yb metal by sorbing them. A significant recovery of the decreased magnetic properties of the ground powders (remanence B r=～0.95 t, coercivity H cj =～227 ka·m -1 and maximum energy product (BH) max=～48 8 kJ·m -3) was observed in accordance with increasing temperature up to 800 ℃. the sorbing temperature and time for Yb metal vapor were optimized and after heating at 800 ℃ for 90 min and annealing subsequently at 610 ℃ for 60 min, the B r, H cj and (BH) max values were increased to be 0.98 t, 712 ka·m -1 and 173 kJ·m -3, respectively. From the microstructural characterizations of resulting samples by using X-ray diffraction (XRD), scanning electron microscopy (SEm), and electron probe X-ray microanalyzer (EPmA), it is found that the sorbed Yb metal uniformly covers the surface and diffuses to the Nd-rich grain boundary of fine ground powders of Nd-Fe-B sintered magnet bulks forming a (Nd,Yb)Fe 2 phase.

关键词： metal materials Nd 2Fe 14B sintered magnets metal vapor sorption magnetic properties recovery rare earths

Lightweight Self Compacting Concrete (Lwscc) in the Ready mix

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Lightweight Self Compacting Concrete (Lwscc) in the Ready Mi...

Vibrational resonance in a multistable system with position-dependent mass

the 6th International Symposium on Cement & Concrete and Canmet/Aci International Symposium on Concrete technology for Sustainable Development

作者： Hela R Hubertová m Bodnárová L Kleka t Brno university of technology Faculty of Civil Engeneering Veveí 95 62 37 Brno Brno university of technology Faculty of Civil Engeneering Veveí 95 62 37 Brno Brno university of technology Faculty of Civil Engeneering Veveí 95 62 37 Brno Prague university of technology Institut of Klokner Solinova 7 662 37 Brno

the paper describes a new field of development and use of self-compacting concrete (SCC) using artificial light-weight aggregate based on burnt clay for coarse fraction of aggregate for transported re

关键词： Lightweight Self Compacting Concrete Lwscc in the Ready mix

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Communications in theoretical Physics 2023年第11期75卷 115-134页

作者： t O Roy-Layinde K A Omoteso O t Kolebaje F O Ogunmefun R A Fasasi J A Laoye U E Vincent Department of Physics Olabisi Onabanjo UniversityAgo-IwoyeOgun StateNigeria Department of Physics Adeyemi Federal University of EducationOndoNigeria Department of Physical Sciences Redeemer’s UniversityP.M.B.230EdeNigeria Department of Physics Lancaster UniversityLancaster LA14 YBUnited Kingdom

the occurrence of vibrational resonance(VR)in a dual-frequency-driven multistable system with a spatially varying mass modelling particle with position-dependent mass(PDm)and evolving in a one-dimensional symmetric periodic potential has been investigated and reported in this *** numerically compute and analyze the response amplitude,the effects of the PDm parameters(m0,a)on the potential structure,the occurrence of VR and the bifurcation of the equilibrium *** is shown that the PDm parameters,besides controlling VR,can induce unconventional resonance patterns through the variation of the potential well *** resonant states can be influenced through the cooperation of the PDm parameters and the external forcing leading the system from multiresonance state into single and double resonance *** contributions of the fixed rest mass m0 on the VR and the PDm-induced resonance are determined by threshold conditions imposed by the magnitude of the mass nonlinear strength a.

关键词： vibrations resonance position-dependent mass multistable oscillator dualfrequency force nonlinear systems