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Achieving exceptional wear resistance in a crack-free high-carbon tool steel fabricated by laser powder bed fusion without pre-heating

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Journal of Materials Science & Technology 2023年第25期156卷 1-19页

作者： Konrad Kosiba daniel wolf Matthias Bönisch Kai Neufeld Ruben Hühne Tobias Gustmann Jozef Bednarčík Hongyu Chen Xiaoliang Han Volker Hoffmann Lukas Beyer Uta Kühn Sergio Scudino Lars Giebeler Julia K.Hufenbach Leibniz Institute for Solid State and Materials Research (IFW) Dresden E.V. Helmholtzstr. 20Dresden 01069Germany Department of Materials Engineering KU LeuvenKasteelpark Arenberg 44bus 2450Leuven 3001Belgium Department of Condensed Matter Physics Institute of PhysicsP.J. Safarik University in KosicePark Angelinum 9Kosice 04154Slovakia Institute of Experimental Physics Slovak Academy of ScienceWatsonova 47Kosice 040 01Slovakia Key Laboratory of Impact and Safety Engineering of Ministry of Education of China Ningbo UniversityNingbo 315211China TU Bergakademie Freiberg Institute of Materials ScienceGustav-Zeuner-Str. 5Freiberg 09599Germany

Laser powder bed fusion(LPBF)for the fabrication of dense components used for tooling applications,is highly *** stresses,which evolve in the additively manufactured part,are inherent to LPBF *** additional stress contribution in high-carbon steels arises from the austenite-to-martensite phase transformation,which may eventually lead to cracking or even *** an alternative to pre-heating the base plate,which is not striven by industry,lowering the martensite content which forms in the part,is essential for the fabrication of dense parts by LPBF of high-carbon tool steels which are then adapted to *** this study,a successful strategy demonstrates the processing of the Fe85Cr4Mo1V1W8C1(wt%)high-carbon steel by LPBF into dense parts(99.8%).The hierarchical microstructure consists of austenitic and martensitic grains separated by elemental segregations in which nanoscopic carbide particles form a network.A high density of microsegregation was observed at the molten pool boundary ultimately forming a *** LPBF-fabricated steel shows a yield strength,ultimate compressive stress,and total strain of 1210 MPa,3556 MPa,and 27.4%,*** mechanical and wear performance is rated against the industrially employed and highly wear-resistant 1.2379 tool steel taken as the *** its lower macro-hardness,the LPBF steel(58.6 HRC,0.0061 mm^(3) Nm^(-1))shows a higher wear resistance than the reference steel(62.6 HRC,0.0078 mm^(3) Nm^(-1)).This behavior results from the wear-induced formation of martensite in a microscale thick layer directly at the worn surface,as it was proven via high-energy X-ray diffraction mapping.

关键词： Additive manufacturing Laser powder bed fusion Steel Wear TRIP

Deriving the coronal hole electron temperature: electron density dependent ionization / recombination considerations

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Research in Astronomy and Astrophysics 2010年第1期10卷 91-95页

作者： John Gerard Doyle Steven Chapman Paul Bryans David Pérez-Suárez Avninda Singh Hugh Summers daniel wolf Savin Armagh Observatory College HillArmagh BT61 9DGN.Ireland Centre for Astrophysics University of Central LancashirePrestonUK Space Science Division Naval Research LaboratoryWashingtonDC 20375USA George Mason University 4400 University DriveFairfaxVA 22020USA Department of Physics & Electronics Deen Dayal Upadhyaya CollegeUniversity of DelhiIndia Department of Physics University of Strathclyde107 RottenrowGlasgowG4 0NGScotland Columbia Astrophysics Laboratory 550 W 120th StNew YorkNY 10027USA

Comparison of appropriate theoretically derived line ratios with observational data can yield estimates of a plasma＇s physical parameters, such as electron density or temperature. The usual practice in the calculation of the line ratio is the assumption of excitation by electrons/protons followed by radiative decay. Furthermore, it is normal to use the so-called coronal approximation, i.e. one only considers ionization and recombination to and from the ground-state. A more accurate treatment is to include ionization/recombination to and from metastable levels. Here, we apply this to two lines from adjacent ionization stages, Mg IX 368A and Mg × 625A, which has been shown to be a very useful temperature diagnostic. At densities typical of coronal hole conditions, the difference between the electron temperature derived assuming the zero density limit compared with the electron density dependent ionization/recombination is small. This, however, is not the case for flares where the electron density is orders of magnitude larger. The derived temperature for the coronal hole at solar maximum is around 1.04MK compared to just below 0.82MK at solar minimum.

关键词： atomic processes - line formation - Sun activity

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A new oxidative pathway of nitric oxide production from oximes in plants

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Molecular Plant 2024年第1期17卷 178-198页

作者： Pedro Lopez-Gomez Javier Buezo Marina Urra Alfonso Cornejo Raquel Esteban Jorge Fernandez de los Reyes Estibaliz Urarte Estefania Rodriguez-Dobreva Alejandro Chamizo-Ampudia Alejandro Eguaras Sebastian wolf daniel Marino Victor Martinez-Merino Jose F.Moran Institute for Multidisciplinary Research in Applied Biology(IMAB) Department of SciencesPublic University of Navarre(UPNA)Avda.de Pamplona 12331192 MutilvaSpain Institute for Advanced Materials and Mathematics(INAMAT2) Department of SciencesPublic University of Navarre(UPNA)Campus de Arosadia31006 PamplonaSpain Department of Plant Biology and Ecology University of the Basque Country(UPV/EHU)Sarriena s/nApdo.64448080 BilbaoSpain Center for Plant Molecular Biology(ZMBP) University of TubingenGeschwister-Scholl-Platz72074 TubingenGermany Institute of Natural Resources and Agrobiology of Salamanca(IRNASA) Department of Plant-Microorganism InteractionsSpanish National Research Council(CSIC)Cordel de Merinas40-5237008SalamancaSpain Department of Biochemistry Area of Molecular BiologyVeterinary FacultyUniversity of LeonCampus de Vegazanas/n.24071 LeonSpain

Nitric oxide(NO)is an essential reactive oxygen species and a signal molecule in *** several studies have proposed the occurrence of oxidative NO production,only reductive routes for NO production,such as the nitrate(NO_(3)^(-))-upper-reductase pathway,have been evidenced to date in land ***,plants grown axenically with ammonium as the sole source of nitrogen exhibit contents of nitrite and NO3−,evidencing the existence of a metabolic pathway for oxidative production of *** hypothesized that oximes,such as indole-3-acetaldoxime(IAOx),a precursor to indole-3-acetic acid,are intermediate oxidation products in NO *** detected the production of NO from IAOx and other oximes catalyzed by peroxidase(POD)enzyme using both 4-amino-5-methylamino-2′,7′-difluorescein fluorescence and *** stimulated the reaction,while superoxide dismutase inhibited ***,mouse NO synthase can also use IAOx to produce NO at a lower rate than *** provided a full mechanism for POD-dependent NO production from IAOx consistent with the experimental data and supported by density functional theory *** showed that the addition of IAOx to extracts from Medicago truncatula increased the in vitro production of NO,while in vivo supplementation of IAOx and other oximes increased the number of lateral roots,as shown for NO donors,and a more than 10-fold increase in IAOx dehydratase ***,we found that in vivo supplementation of IAOx increased NO production in Arabidopsis thaliana wild-type plants,while prx33-34 mutant plants,defective in POD33-34,had reduced *** data show that the release of NO by IAOx,as well as its auxinic effect,explain the superroot ***,our study reveals that plants produce NO utilizing diverse molecules such as oximes,POD,and flavins,which are widely distributed in the plant kingdom,thus introducing a long-awaited oxidative pathway to NO production in plants.T

关键词： ammonium oxidation auxin nitric oxide oxime peroxidase root phenotype

分子离子NH+与电子的复合解离研究（英文）

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IMP & HIRFL Annual Report 2012年 215-216页

作者：杨变 Novotny Oldňich KrantzClaude BuhrHenrik MendesMario Nordhorn Christian Geppert Dietrich wolf Berg Max BingDennis Domesle Christian Grussie Florian Savin wolf daniel Schwalm Dirk CaiXiaohong wolf Andreas Max Planck Institute for Nuclear Physics University of Chinese Academy of Sciences Columbia Astrophysics Laboratory Columbia University Department of Particle Physics Weizmann Institute of Science Department of Physics Stockholm University

Dissociative recombination(DR)of molecular ions with electrons is one of the key processes in low density and low temperature plasma *** removes ionized species and produces neutral fragments,thus affecting chemical composition of the *** coefficient,fragmentation branching ratios and excitation of final fragments resulted from DR gives helpful information for modeling these plasmas.

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Acute Effect of High-Intensity Climbing on Performance and Muscle Oxygenation in Elite Climbers

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Journal of Science in Sport and Exercise 2022年第2期4卷 145-155页

作者： Andri Feldmann Remo Lehmann Frieder Wittmann Peter wolf Jiří Baláš daniel Erlacher Institute of Sport Science University of BernBremgartenstrasse 1453012 BernSwitzerland Sensory-Motor Systems Lab ETH ZürichTannenstrasse 1TAN E5.18092 ZurichSwitzerland Faculty of Physical Education and Sport Charles UniversityJoséMartího 31Prague 616252Czech Republic

High-intensity training(HIT)is known to have deteriorating effects on performance which manifest in various physiological changes such as lowered force production and oxidative ***,the effect of HIT in climbing on finger flexor performance has not been investigated ***-one climbers partook in an intervention study with three assessment time points:pre-HIT,post-HIT,and 24-h *** HIT involved four five-minute exhaustive climbing *** climbers were assigned to a control *** consisted of three finger flexor tests:maximum voluntary contraction(MVC),sustained contraction(SCT),and intermittent contraction tests(ICT).During the SCT muscle oxygenation(SmO_(2))metrics were collected via NIRS sensors on the *** HIT had significant deteriorating effects on all force production metrics(MVC−18%,SCT−55%,ICT−59%).Post-24 h showed significant recovery,which was less pronounced for the endurance tests(MVC−3%,SCT−16%,ICT−22%).SmO_(2)metrics provided similar results for the SCT with medium to large effect *** attainable SmO_(2)and resting SmO_(2)both showed moderate negative correlations with pre-HIT force production respectively;r=−0.41,P=0.102;r=−0.361,P=0.154.A strong association was found between a loss of force production and change in minimally attainable SmO_(2)(r=−0.734,P=0.016).This study presents novel findings on the deteriorating effects of HIT on finger flexor performance and their oxidative ***,the divergent results between strength and endurance tests should be of interest to coaches and athletes when assessing athlete readiness.

关键词： NIRS HIT Tissue oxygenation MVC Isometric Finger flexors

4 - 16 Dissociative Recombination of Imidogen Radical Ions

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IMP & HIRFL Annual Report 2012年第1期 215-216页

作者： Yang Bian Novotny Oldnich KrantzClaude BuhrHenrik MendesMario Nordhorn Christian Geppert Dietrich wolf Berg Max BingDennis Domesle Christian Grussie Florian Savin wolf daniel Schwalm Dirk CaiXiaohong wolf Andreas

Stability prediction of hard rock pillar using support vector machine optimized by three metaheuristic algorithms

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矿业科学技术学报:英文版 2023年第8期33卷 1019-1036页

作者： Chuanqi Li Jian Zhou Kun Du daniel Dias School of Resources and Safety Engineering Central South UniversityChangsha 410083China Laboratory 3SR CNRS UMR 5521Grenoble Alpes UniversityGrenoble 38000France

Hard rock pillar is one of the important structures in engineering design and excavation in underground *** and convenient prediction of pillar stability is of great significance for underground space *** paper aims to develop hybrid support vector machine(SVM)models improved by three metaheuristic algorithms known as grey wolf optimizer(GWO),whale optimization algorithm(WOA)and sparrow search algorithm(SSA)for predicting the hard rock pillar *** integrated dataset containing 306 hard rock pillars was established to generate hybrid SVM *** parameters including pillar height,pillar width,ratio of pillar width to height,uniaxial compressive strength and pillar stress were set as input *** global indices,three local indices and the receiver operating characteristic(ROC)curve with the area under the ROC curve(AUC)were utilized to evaluate all hybrid models’*** results confirmed that the SSA-SVM model is the best prediction model with the highest values of all global indices and local ***,the performance of the SSASVM model for predicting the unstable pillar(AUC:0.899)is not as good as those for stable(AUC:0.975)and failed pillars(AUC:0.990).To verify the effectiveness of the proposed models,5 field cases were investigated in a metal mine and other 5 cases were collected from several published *** validation results indicated that the SSA-SVM model obtained a considerable accuracy,which means that the combination of SVM and metaheuristic algorithms is a feasible approach to predict the pillar stability.

关键词： Underground pillar stability Hard rock Support vector machine Metaheuristic algorithms

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A compositional function hybridization of PSO and GWO for solving well placement optimisation problem

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Petroleum Research 2022年第3期7卷 401-408页

作者： daniel Ocran Sunday Sunday Ikiensikimama Eric Broni-Bediako University of Mines and Technology(UMaT) Department of Petroleum and Natural Gas EngineeringTarkwaGhana Universty of Port Harcourt Department of Petroleum and Natural Gas EngineeringPort HarcourtNigeria

Advances in technology and optimisation are helping to improve decision making in the oil and gas ***,most of the traditional metaheuristic algorithms applied in well placement optimisation problems suffer from extensive parameter experimentations and local optimum trapping *** couples with the complex and heterogeneous nature of hydrocarbon reservoirs and increased decision variables poses severe simulation process *** study considered a functional composition integration approach to formulate a robust hybrid metaheuristic algorithm called *** HGWO-PSO leverages on the strengths of Grey wolf Optimiser(GWO)and Particle Swarm Optimisation(PSO)and the Clerc's parameter setting considerations.A rigorous approach which enforces regulatory agreed minimum well spacing was incorporated in the optimisation *** models ranging from unimodal to multimodal spatial systems were used as examples to test the explorative and exploitative capabilities of the *** this paper we show the performance curve and statistical analysis of HGWO-PSO as a well placement algorithm and compares its performance with that of standalone PSO,and GWO and the traditional Genetic Algorithm(GA).Results revealed that the HGWO-PSO demonstrated comparative performances in terms of exploration and exploitation obtaining the best optimal solutions which give highest contractor's NPVs in majority of cases ***,the means and standard deviations for HGWO-PSO among the various runs showed consistent and efficient *** Wilcoxon signed rank test conducted gave very low p-values suggesting uniqueness of HGWO-PSO from the other metaheuristic ***,the computational speed of HGWO-PSO was relatively better as compared to the individual GWO and PSO in most the test *** simulation results for all test cases confirm that implementation of HGWO-PSO can cause considerable improvement in locations of wells even in hete

关键词： Well location optimisation Metaheuristic algorithms Oilfield development Hybridisation

Serum Concentrations of Tumor Necrosis Factor-α and its Soluble Receptors in Soldiers with and Without Combat-related Posttraumatic Stress Disorder： Influence of Age and Body Mass Index

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Chinese Medical Journal 2016年第6期129卷 751-752页

作者： Hubertus Himmerich Jorg-Egbert wolf Peter Zimmermann Antje H Biihler Lesca M Holdt daniel Teupser Kenneth C Kirkby Gerd D Willmund Ulrich Wesemann Department of Psychiatry Psychotherapy and Psychotraumatology Bundeswehr Hospital Berlin Germany Department of Psychological Medicine King's College London London UK Department of Psychiatry and Psychotherapy University Hospital Leipzig Leipzig Germany Department of Laboratory Medicine Ludw g-Max m ans-University Munich Germany Department of Psychiatry University of Tasmania Hobart Tasmania Australia

To the Editor： With great interest we read the original article of Chert et al published in the Chinese Medical Journal comparing serum concentrations of cytokines in patients of Han and Li ethnicity with posttraumatic stress disorder （PTSD）. The authors found significantly higher serum concentrations of the cytokines interleukin （IL）-2, IL-6, IL-8, and tumor necrosis factor （TNF）-α in PTSD patients compared to normal controls, and differences in cytokine concentrations according to ethnicity.

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