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Journal of Iron and Steel Research International 2022年第5期29卷 819-835页

作者： J.l.Guo t.J.Chen State Key laboratory of Advanced Processing and Recycling of Nonferrous Metals Lanzhou University of TechnologyLanzhou730050GansuChina

the effects of H_(2)SO_(4)concentration and current in electrochemical corrosion on surface layer softening or plasticizing of Q235 steel bar and their effects on subsequent electrochemical cold drawing(ECD)were *** results indicate that the electrochemical corrosion can soften or plasticize the surface layer of Q235 steel bar and then make the subsequent ECD be conducted more *** softening degree and thickness of the surface layer are continuously enhanced with increasing corrosion rate,i.e.,increasing H_(2)SO_(4)concentration or current,due to the generation of more vacancy clusters in deeper regions of surface *** vacancy clusters then relax dislocations through being absorbed during ECD,and the formation and movement of additional dislocation flux are thereby enhanced,resulting in the further obvious decrease in the drawing *** is also due to the enhanced formation and movement of additional dislocation flux that the dislocation density and thus the hardness of the surface layer are decreased,as well as that the texture structure is *** behaviors are enhanced as the corrosion rate increases.

关键词： Electrochemical corrosion Electrochemical cold drawing Surface layer softening Vacancy Additional dislocation flux

Photoelectrochemical Iron-Catalyzed C(sp^(3))-H Borylation of Alkanes in a Position-Selective Manner

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CCS Chemistry 2024年第6期6卷 1430-1438页

作者： Wen Wei Bin Wang Simon l.Homölle Jinbin Zhu Yanjun li tristan von Münchow Isaac Maksso lutz Ackermann Institut für Organische und Biomolekulare Chemie Georg-August-Universität Göttingen37077 Göttingen

Catalytic C-H borylation is of prime topical importance,since easily available feedstock chemicals can thereby be transformed into valuable transient functional groups in the absence of directing ***,we disclose an iron-catalyzed C(sp^(3))-H borylation of simple,non-prefunctionalized alkanes,providing access to value-added products in a single step by means of *** power of merging photo-and electrochemistry was mirrored by ample scope and exceedingly mild reaction ***,an outstanding position-selectivity in favor of primary C(sp^(3))-H proved viable within the photoelectrochemical borylation through a chemo-selective anodic overoxidation *** ferro-photoelectrochemistry strategy avoids toxic precious transition metals,enabling C(sp^(3))-H borylations in a site-selective fashion.

关键词： photoelectrocatalysis C(sp^(3))-H borylation iron catalysis position-selectivity chlorine radical

two-dimensional atomically thin Pt layers on MXenes: the role of electronic effects during catalytic dehydrogenation of ethane and propane

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Nano Research 2024年第3期17卷 1251-1258页

作者： Zhe li tobias K.Misicko Fan Yang Xiaopeng liu Zhenwei Wu Xiaoyang Gao tao Ma Jeffrey t.Miller Daniela S.Mainardi Collin D.Wick Zhenhua Zeng Yang Xiao Yue Wu Department of Chemical and Biological Engineering Iowa State University618 Bissell RoadAmesIA 50011USA Institute for Micromanufacturing Louisiana Tech University505 Tech DriveRustonLA 71272USA Davidson School of Chemical Engineering Purdue University480 Stadium Mall DriveWest LafayetteIN 47907USA Michigan Center for Materials Characterization University of Michigan2800 Plymouth RdAnn Arbor MI 48109USA College of Engineering and Science Louisiana Tech UniversityRustonLA 71272USA

Atomically thin Pt nanolayers were synthesized on the surface of Mo2tiC2 MXenes and used for the catalytic dehydrogenation of ethane and propane into ethylene and propylene,two important chemicals for the petrochemical *** compared with Pt nanoparticles,the atomically thin Pt nanolayer catalyst showed superior coke-resistance(no deactivation for 24 h),high activity(turnover frequencies(tOFs)of 0.4–1.2 s^(-1)),and selectivity(>95%)toward ethylene and *** unique Pt nanolayer has a similar geometric surface to Pt nanoparticles,enabling the investigations of the electronic effect on the catalytic performance,where the geometric effect is *** is found that the electronic effect plays a critical role in dehydrogenative product selectivity and catalyst *** metal–support interaction is found dependent on the substrate and metal components,providing wide opportunities to explore high-performance MXene-supported metallic catalysts.

关键词： MXene catalysis alkane dehydrogenation nanolayers

tracking the ti^(4+)substitution in phlogopite by spectroscopic imaging:A tool for unravelling the growth of micas at HP-Ht conditions

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Geoscience Frontiers 2024年第3期15卷 1-13页

作者： G.Della Ventura N.El Moutaouakkil B.Boukili S.Bernardini A.Sodo l.Pronti M.Cestelli-Guidi F.Holtz F.lucci Dipartimento di Scienze UniversitàRoma TreRomaItaly INFN-lNF via Fermi 200040 FrascatiRomaItaly INGV Via di Vigna Murata 60500143 RomaItaly laboratory of Géosciences Water and Environment.Department of Earth Sciences.Faculty of SciencesUniversity Mohammed VRabatMorocco leibnitz Universität Hannover Institute of MineralogyCallinstr 330167 HannoverGermany Dipartimento di Scienze della terra e Geoambientali Universitàdi Bari“Aldo Moro”BariItaly

Phlogopite solid-solutions have a wide pressure-temperature(P-t)stability field and are ubiquitous in a wide variety of geological settings,from deep lithosphere magmatic environments to upper crust metamorphic *** composition represents therefore a valuable physical-chemical archive and may provide important information regarding its crystallization and the petrogenesis of the *** this paper we examine the phlogopite phenocrysts from the well-known Fort Regent mica-bearing lamprophyre minette from ***(Island of Jersey,UK).Phlogopite phenocrystals from lamprophyres generally show normal-step and continuous compositional zoning,however those from the Fort Regent minette show a peculiar texture characterized by dark brown high-ti(average tiO_(2)≈8.5 wt.%)cores enveloped by euhedral low-to mid-amplitude zonation due to oscillatory contents in ti,Fe and ***-barometry modelling based on biotite-only composition yields relatively high P-t estimates(t≈970±54℃at P≈0.73±0.13 GPa)for cores whereas lower values(t≈790±54℃at P≈0.29±0.13 GPa)are obtained for the outer *** temperatures(t≈1075±54℃)but extremely high and anomalous pressure values(P≈1.82±0.13 GPa)are obtained for the yellowish inner *** combination of electron micro probe(EMP)analysis and single-crystal infra-red(FtIR)imaging in the OH-stretching region shows that the exceptional and oscillatory ti contents are due to the ti-vacancy substitution,typical of crystallization and growth processes of HP/Ht *** imaging provides additional insight for this process,confirming the dominant dioctahedral nature for the ti-Fe-rich cores and outer *** of thermobaric estimates obtained from the phlogopite compositiononly model,based on the fine-scale compositional evolution,shows that pressure-temperature values from low-ti high-Mg domains should be carefully evaluated because the substitution mechanisms during the dark mica growth are not univocal

关键词： ti-phlogopite Jersey minette(UK) ti-substitution FtIR imaging Raman imaging thermobarometric modelling

Influences of residual stress and micro-deformation on microstructures and mechanical properties for ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy produced by laser powder bed fusion

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Journal of Materials Science & technology 2021年第16期75卷 174-183页

作者： C.C.Zhang H.l.Wei t.t.liu l.Y.Jiang t.Yang W.H.liao National Joint Engineering Research Center of NC Forming technology and Equipment School of Mechanical EngineeringNanjing University of Science and TechnologyNanjing 210094China

laser powder bed fusion(lPBF)yields unique advantages during the fabrication of titanium *** the present work,ti-6.5 Al-3.5 Mo-1.5 Zr-0.3 Si alloy specimens with excellent mechanical performances were fabricated by *** as-built specimens displayed relatively high strength and ductility under modest volume energy densities(VEDs),whereas they manifested high strength with low ductility under high *** investigate the key reason of this phenomenon,the specimens were designed with two VEDs ranges of 60 J/mm^(3) and 85 J/mm^(3).Special attention was paid to the influences of residual stress and micro-deformation on microstructures and mechanical properties for the first *** results indicated that the residual stresses and relative density of the 60 J/mm^(3) range specimens were higher than that of the 85 J/mm3 range *** multiplication and dislocation movement promoted by the residual stress were hindered by the initialα’phase grain boundary(prior-α’GB),leading to the formation ofα’metastable *** mean tensile strength and elongation of the 60 J/mm^(3) range specimens were 1248.1 MPa and 12.3%,respectively,whereas the corresponding values for the 85 J/mm^(3) range specimens were 1405.3 MPa,5.0%,*** deformation,the strength and ductility of the specimens were first improved by lamellar structures generated from prior-α’phases,and then effectively enhanced by the interaction between the{10–12}twins and ***,pores significantly reduced the ductility;hence,high VED specimens with large twins and numerous large pores increased the strength and reduce the ductility.

关键词： laser powder bed fusion ti-6.5Al-3.5Mo-1.5Zr-0.3Si alloy Residual stress twin Mechanical properties

long-time Shoreline Monitoring of the Vellar Estuarine Complex,Southeast Coast of India:Using Multispectral Satellite Data

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Journal of Earth Science 2012年第6期23卷 900-907页

作者： l Senthilnathan E P Nobi t thangaradjou l Kannan Centre of Advanced Study in Marine Biology Faculty of Marine SciencesAnnamalai UniversityParangipettai-608502TamilnaduIndia

the present study was carried out to track the path of Vellar estuary over a period of 38 years （1970-2008） and also to detect the impact of tsunami on estuarine complex of the Vellar estuary. Visual interpretation techniques were employed by using muitispectral data of landsat tM （1991） and IRS-P6 lISS III （2004, 2006, and 2008） to delineate shoreline changes in the VeUar estuarine complex. Results clearly revealed the changes that occurred along the estuarine path over the period, and severe erosion was noticed in the seaward side of the MGR thittu and accretion, along the estuarine mouth. It is also visible that there is clear river path shift in the river course. Although the sandbar formation was seen with only little morphologic modification up to 2004, the Indian Ocean tsunami that struck this coast （26 December, 2004） distorted the sandbar of the Vellar estuarine mouth; however, the 2006 satel- lite images confirmed that the sandbar was formed again to its original structure as that of before the tsunami.

关键词： estuary geomorphology IRS-P6 lISS III shoreline tsunami India.

A New Proof for Congruent Number’s Problem via Pythagorician Divisors

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Advances in Pure Mathematics 2024年第4期14卷 283-302页

作者： léopold Dèkpassi Keuméan François Emmanuel tanoé UFR Mathematics and Computer Science F&#233lix Houphou&#235t Boigny University Abidjan Cote d&#8217Ivoire

Considering Pythagorician divisors theory which leads to a new parameterization, for Pythagorician triplets ( a,b,c )∈ ℕ 3∗ , we give a new proof of the well-known problem of these particular squareless numbers n∈ ℕ ∗ , called congruent numbers, characterized by the fact that there exists a right-angled triangle with rational sides: ( A α ) 2 + ( B β ) 2 = ( C γ ) 2 , such that its area Δ= 1 2 A α B β =n;or in an equivalent way, to that of the existence of numbers U 2 , V 2 , W 2 ∈ ℚ 2∗ that are in an arithmetic progression of reason n;Problem equivalent to the existence of: ( a,b,c )∈ ℕ 3∗ prime in pairs, and f∈ ℕ ∗ , such that: ( a−b 2f ) 2 , ( c 2f ) 2 , ( a+b 2f ) 2 are in an arithmetic progression of reason n;And this problem is also equivalent to that of the existence of a non-trivial primitive integer right-angled triangle: a 2 + b 2 = c 2 , such that its area Δ= 1 2 ab=n f 2 , where f∈ ℕ ∗ , and this last equation can be written as follows, when using Pythagorician divisors: (1) Δ= 1 2 ab= 2 S−1 d e ¯ ( d+ 2 S−1 e ¯ )( d+ 2 S e ¯ )=n f 2;Where ( d, e ¯ )∈ ( 2ℕ+1 ) 2 such that gcd( d, e ¯ )=1 and S∈ ℕ ∗ , where 2 S−1 , d, e ¯ , d+ 2 S−1 e ¯ , d+ 2 S e ¯ , are pairwise prime quantities (these parameters are coming from Pythagorician divisors). When n=1 , it is the case of the famous impossible problem of the integer right-angled triangle area to be a square, solved by Fermat at his time, by his famous method of infinite descent. We propose in this article a new direct proof for the numbers n=1 (resp. n=2 ) to be non-congruent numbers, based on an particular induction method of resolution of Equation (1) (note that this method is efficient too for general case of prime numbers n=p≡a ( ( mod8 ) , gcd( a,8 )=1 ). to prove it, we use a classical proof by induction on k , that shows the non-solvability property of any of the following systems ( t=0 , corresponding to case n=1 (resp. t=1 , corresponding to case n=2 )): ( Ξ t,k ){ X 2 + 2 t ( 2 k Y ) 2 = Z 2 X 2 + 2

关键词： Prime Numbers-Diophantine Equations of Degree 2 & 4 Factorization Greater Common Divisor Pythagoras Equation Pythagorician triplets Congruent Numbers Inductive Demonstration Method Infinite Descent BSD Conjecture

Colorectal cancer and dysplasia in inflammatory bowel disease

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World Journal of Gastroenterology 2008年第17期14卷 2662-2669页

作者： timothy l Zisman David t Rubin Clinical Research Fellow in Gastro-enterology the University of Chicago Medical Center the University of Chicago Medical Center

Both ulcerative colitis and Crohn’s disease carry an increased risk of developing colorectal cancer. Established risk factors for cancer among patients with inflammatory bowel disease (IBD) include the younger age at diagnosis, greater extent and duration of disease, increased severity of inflammation, family history of colorectal cancer and coexisting primary sclerosing cholangitis. Recent evidence suggests that current medical therapies and surgical techniques for inflammatory bowel disease may be reducing the incidence of this complication. Nonetheless heightened vigilance and a careful, comprehensive approach to prevent or minimize the complications of invasive cancer are warranted in this unique cohort of patients. Current guidelines for the prevention and early detection of cancer in this high risk population are grounded in the concept of an inflammation-dysplasia- carcinoma sequence. A thorough understanding of the definition and natural history of dysplasia in IBD, as well as the challenges associated with detection and interpretation of dysplasia are fundamental to developing an effective strategy for surveillance and prevention, and understanding the limitations of the current approach to prevention. this article reviews the current consensus guidelines for screening and surveillance of cancer in IBD, as well as presenting the evidence and rationale for chemoprevention of cancer and a discussion of emerging technologies for the detection of dysplasia.

关键词： Cancer Dysplasia Inflammatory Bowel Disease Ulcerative Colitis Crohn's Disease Chemoprevention

Multiscale and multiphysics explorations of the transient deposition processes and additive characteristics during laser 3D printing

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Journal of Materials Science & technology 2021年第18期77卷 196-208页

作者： H.l.Wei F.Q.liu l.Wei t.t.liu W.H.liao School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing.210094China State Key laboratory of Solidification Processing Northwestern Poly technical UniversityXi'an710072China

laser directed energy deposition(DED)involves complex physical processes,and the trial and error examinations are time consuming and cost *** research paradigm can be reshaped using advanced phenomenological models via computing the spatiotemporal variations of the build *** this work,multi-layer and multi-track laser DED of ti-6 Al-4 V were systematically explored on multiple scales including the 1D track,the 2D layer and the 3D full build considering the complex transport of energy,mass,and momentum in the moving freeform molten *** results showed that convex,nearflat,and wavy builds were generated using gradually larger hatch *** profiles of individual tracks and layers were extracted through the unique advantages of the *** individual tracks exhibited various patterns and rotated with specific inclinations to form distinct layer *** net increments of the deposit generated upon the printing of a new track during the continuous deposition process showed that the smaller hatch spacing caused higher overlap rate of horizontally adjacent tracks but lower remelting rate of vertically adjacent tracks in neighboring *** 3D numerical model was validated with corresponding experiments for various process *** scientific findings can provide useful insights for further researches of DED.

关键词： Additive manufacturing Multi-layer and multi-track Numerical model Build features Molten pool

伊尔加兹山脉冰缘地貌发育和土壤形成及其气候的影响(土耳其黑海西岸)

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Journal of Geographical Sciences 2024年第3期34卷 543-570页

作者： DEDE Volkan DENGIZ Orhan DEMIRAG tURAN inci tüRKES Murat SENOl Hüseyin SERIN Soner Department of Geography Ardahan UniversityArdahan75002Türkiye Department of Soil Science and Plant Nutrition Faculty of AgricultureOndokuz Mayıs UniversitySamsun55139Türkiye Department of Geography Faculty of Human and Social SciencesSamsun UniversitySamsun55080Türkiye Center for Climate Change and Policy Studies Boğaziçi Universityİstanbul34342Türkiye Faculty of Agriculture Department of Soil Science and Plant NutritionIsparta University of Applied SciencesIsparta32200Türkiye Institute of Social Sciences İstanbul Universityİstanbul34119Türkiye

the main aims of the current study are to determine the morphological features of the periglacial landforms(non-sorted step,mud circle,stony earth circle,thufur,and congeliturbation)located on the Ilgaz Mountains,examine the physicochemical and mineralogical properties with pedological processes of the soils,and assess of the effects of climatic conditions controlling the development of *** Ilgaz Mountains(2587 m a.s.l.),located in the Western Black Sea Region,within the Anatolian Mountains,are important in terms of periglacial landforms(mud circles,stony earth circles,thufurs,non-sorted steps,non-sorted stripes,congeliturbation deposits,and block currents).the descriptive statistics of 123 periglacial landforms measured by fieldworks were *** distribution of freezing and thawing in the Ilgaz Mountains throughout the year was evaluated,and it was found that freezing takes place between December and March,freezing-thawing takes place in April,May,October and November,and thawing takes place between June and *** to soil properties,organic matter content changes from 1.88%to 12.72%in non-sorted step soils,while it is between 2.03%and 12.24%in stony earth circle *** organic matter is observed to be close to congeliturbation deposits at lower ratios compared to non-sorted steps,stony earth circles and mud *** soil reactions on stony earth circles and non-sorted steps vary between slightly acidic and slightly *** the other hand,soil samples taken from the mud circles are different from those taken from the non-sorted steps and stony earth *** soil reaction is acidic,and pH changes between 4.86 and *** lime content also varies between 2.81%and 32.08%,with an average of 12.02%.the texture properties of soils are dominantly loam and clay loam,as in the non-sorted steps,stony earth circles,and mud *** their mineralogical properties,the XRD study was carried out to determine the primer mineral

关键词： periglacial landforms soil formation climate effect Ilgaz Mountains türkiye