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Robust interface and excellent as-built mechanical properties of Ti–6Al–4V fabricated through laser-aided additive manufacturing with powder and wire

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 154-168页

作者： Fei Weng guijun Bi youxiang Chew Shang Sui Chaolin Tan Zhenglin Du Jinlong Su Fern Lan ng Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials Ministry of EducationShandong Engineering&Technology Research Center for Superhard MaterialSchool of Materials Science and EngineeringShandong UniversityJinan 250061China Institute of Intelligent Manufacturing Guangdong Academy of SciencesGuangzhou 510095China Singapore Institute of Manufacturing Technology 5 Cleantech Loop636732Singapore

The feasibility of manufacturing Ti-6Al-4V samples through a combination of laser-aided additive manufacturing with powder(LAAM_(p))and wire(LAAM_(w))was explored.A process study was first conducted to successfully circumvent defects in Ti-6Al-4V deposits for LAAM_(p) and LAAM_(w),*** the optimized process parameters,robust interfaces were achieved between powder/wire deposits and the forged substrate,as well as between powder and wire *** characterization results revealed the epitaxial prior β grains in the deposited Ti-6Al-4V,wherein the powder deposit was dominated by a finerα′microstructure and the wire deposit was characterized by lamellar α *** mechanisms of microstructure formation and correlation with mechanical behavior were analyzed and *** mechanical properties of the interfacial samples can meet the requirements of the relevant Aerospace Material Specifications(AMS 6932)even without post heat *** fracture occurred within the interfacial area,further suggesting the robust *** findings of this study highlighted the feasibility of combining LAAM_(p) and LAAM_(w) in the direct manufacturing of Ti-6Al-4V parts in accordance with the required dimensional resolution and deposition rate,together with sound strength and ductility balance in the as-built condition.

关键词： laser-aided additive manufacturing powder deposition wire deposition interfacial characteristic mechanical behavior

Cortical hem signaling center: functions, development, and potential implications for evolution and brain disorders

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Neural Regeneration Research 2025年第4期20卷 1079-1080页

作者： Victor V.Chizhikov Igor y.Iskusnykh Department of Anatomy and Neurobiology University of Tennessee Health Science CenterMemphisTNUSA

Development of the telencephalon relies upon several signaling centers-localized cellular populations that supply secreted factors to pattern the cortical *** such signaling center is the cortical hem,which arises during embryonic development at the telencephalic dorsal midline,adjacent to the choroid plexus and hippocampal primordium(Figure 1A).While the cortical hem has also been described in reptiles and birds,most of our knowledge about the developmental roles of the cortical hem is derived from the analysis in *** cortical hem produces several types of secreted molecules,including wingless-related integration site(Wnt)and bone morphogenetic(Bmp)*** cortical hem is particularly important for the development of the hippocampus,which is involved in learning and memory,and the neocortex,which is the most complex brain region that mediates multiple types of behavior and higher cognitive functions(Mangale et al.,2008;Dal-Valle-Anton and Borrell,2022).

关键词： epithelium Figure center

Species limits in the Elegant Pitta (Pitta elegans) complex from Wallacea based on bioacoustic and morphometric analysis

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Avian Research 2020年第4期11卷 421-432页

作者： Arya y.yue Elize y.x.ng James A.Eaton Frank E.Rheindt Bryn Mawr College Department of Biology101 N Merion AveBryn MawrPA 19010USA Department of Biological Sciences National University of Singapore16 Science Drive 4Singapore 117558Singapore A-3A-5 Casa Indah IPersiaran Surian47810 Petaling JayaMalaysia

Background:The Elegant Pitta(Pitta elegans)complex displays a remarkable diversity of morphological and bioacoustic traits across five taxa currently recognized as *** differ in plumage characteristics(such as red versus black belly patches;supercilium color and extent;and white versus black throats),in lifestyle(resident versus migratory)and in *** investigated the morphological,bioacoustic and ecological differences across all taxa after recent studies demostrated the importance of these traits in recognizing biological species limits across ***:Morphometric analysis was carried out by measuring tarsus,wing,tail and bill lengths of 15 specimens at the Natural History Museum,UK,and plumages were inspected across 106 unique individuals from four different *** analysis was based on 134 range-wide sound *** types of calls,territorial calls and alarm calls,were analyzed using different sets of *** component analysis and the Isler Criterion were applied to the *** trials were conducted to explore the levels of response of each taxon to the call types of the other ***:The territorial call of concinna exhibits a distinct two-element motif,while elegans,maria and virginalis utter a three-element motif in which the first two elements are given in quick *** the other hand,vigorsii,produces both two-element and three-element motifs with longer breaks in between *** further corroborated by the playback trials,the three taxa elegans,virginalis and maria form a tight vocal cluster,whereas each concinna and vigorsii are *** alarm call turned out to be less diagnostic even though most taxa did roughly separate into different vocal *** analysis failed to produce strong differences,but plumage distinctions among multiple taxa are ***:We suggest splitting the Elegant Pitta into three biological species based on

关键词： Bioacoustic analysis Elegant Pitta Morphometric analysis Pitta elegans Territorial calls

One-dimensional non-Darcy flow in a semi-infinite porous media:a multiphase implicit Stefan problem with phases divided by hydraulic gradients

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Acta Mechanica Sinica 2017年第5期33卷 855-867页

作者： g.Q.Zhou y.Zhou x.y.Shi State Key Laboratory for geomechanics and Deep Underground Engineering China University of Mining and Technology School of Mechanics and Civil Engineering China University of Mining and Technology JiangSu Collaborative Innovation Center for Building Energy Saving and Construct Technology

One-dimensional non-Darcy flow in a semi-infinite porous media is investigated. We indicate that the non-Darcy relation which is usually determined from experimental results can always be described by a piecewise linear function, and the problem can be equivalently transformed to a multiphase implicit Stefan problem. The novel feature of this Stefan problem is that the phases of the porous media are divided by hydraulic gradients, not the excess pore water pressures. Using the similarity transformation technique, an exact solution for the situation that the external load increases in proportion to the square root of time is developed. The study on the existence and uniqueness of the solution leads to the requirement of a group of inequalities. A similar Stefan problem considering constant surface seepage velocity is also investigated, and the solution, which we indicate to be uniquely existent under all conditions, is established. Meanwhile, the relation between our Stefan problem and the traditional multiphase Stefan problem is demonstrated. In the end, computational examples of the solution are presented and discussed. The solution provides a useful benchmark for verifying the accuracy of general approximate algorithms of Stefan problems, and it is also attractive in the context of inverse problem analysis.

关键词： Moving boundary problem Stefan problem Analytical solution Non-Darcy flow Soil consolidation

Stepping up after spinal cord injury:negotiating an obstacle during walking

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Neural Regeneration Research 2025年第7期20卷 1919-1929页

作者： Alain Frigon Charly g.Lecomte Department of Pharmacology-Physiology Faculty of Medicine and Health SciencesUniversitéde SherbrookeCentre de recherche du Centre Hospitalier Universitaire de SherbrookeSherbrookeQCCanada

Every day walking consists of frequent voluntary modifications in the gait pattern to negotiate *** spinal cord injury,stepping over an obstacle becomes *** over an obstacle requires sensorimotor transformations in several structures of the brain,including the parietal cortex,premotor cortex,and motor *** information and planning are transformed into motor commands,which are sent from the motor cortex to spinal neuronal circuits to alter limb trajectory,coordinate the limbs,and maintain *** spinal cord injury,bidirectional communication between the brain and spinal cord is disrupted and animals,including humans,fail to voluntarily modify limb trajectory to step over an ***,in this review,we discuss the neuromechanical control of stepping over an obstacle,why it fails after spinal cord injury,and how it recovers to a certain extent.

关键词： biomechanics locomotion neurophysiology obstacle negotiation spinal cord injury

Enhanced pitting corrosion resistance of a Zr-based metallic glass by ultraviolet light irradiation

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Journal of Iron and Steel Research International 2023年第8期30卷 1642-1649页

作者： Z.Chen D.P.Wang S.Wang y.x.geng y.x.guo y.C.Wu Z.g.Liu y.y.Zhang y.x.Wang School of Materials Science and Engineering Jiangsu University of Science and Technology.Zhenjiang 212003JiangsuChina School of Mechanical Engineering Jiangsu University of Science and TechnologyZhenjiang 212003JiangsuChina

The influence of ultraviolet light irradiation on the pitting corrosion performance of a Zr_(2)Ni metallic glass was examined using electrochemical methods and immersion test in 0.05 mol/L NaCl *** the results of potentiostatic polarization,the pitting potential of the ultraviolet light-irradiated sample shifted positively with a value of~300 mV,revealing the enhanced pitting corrosion resistance of the *** corrosion morphology after the immersion test also demonstrated lower degree of corrosion damage and improved pitting resistance of the sample with ultraviolet light irradiation.x-ray photoelectron spectroscopy analysis revealed more zirconium enrichment in the passive film and no chloride ions adsorption for the samples with ultraviolet irradiation,accounting for the suppression of the pit generation and *** findings indicate that ultraviolet light irradiation improves the pitting corrosion resistance of the Zr-based metallic glasses,which are promising structural materials to be used in corrosion environments with high ultraviolet irradiation.

关键词： Metallic glass Pitting-Corrosion Ultraviolet light irradiation Passive film

Co-substitution of zirconium and neodymium on hyperfine interactions and AC susceptibility of SrFe12O19 nanohexaferrites

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Journal of Rare Earths 2020年第3期38卷 265-273页

作者： M.A.Almessere y.Slimani H.güngünes A.Baykal Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia Department of Biophysics Institute for Research&Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia Department of Physics Hitit University19030Cevre Yolu Bulvan-CorumTurkey Department of Nano-Medicine Research Institute for Research&Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityP.O.Box 198231441DammamSaudi Arabia

This study presents the influence of Zn and Nd co-substitution on structure,morphology,AC susceptibility and ZFC-FC magnetizations of Sr nanohexaferrites(NHFs),SrFe12-x(Zn,Nd)xO19(0.0≤x≤1.0),which was produced by sol-gel *** powder patterns,scanning electron microscopy(SEM) and high-resolution transmission electron spectroscopy(HR-TEM) approve the synthesis of Sr M-type *** spectra show that Zn^2+ions occupy 2 b and 4f1 sites while Nd3+ions locate at 2 a,4f2 and 12 k *** magnetic properties of the produced Sr-NHFs were investigated also by ZFC-FC magnetizations and AC *** to the MFC-MZFC results(between 2 and 400 K),no blocking temperature was detected which indicates the ferromagnetic(FM) behavior of *** lower temperatures,a super-spin glass like behavior is *** AC susceptibility indicates that the magnetic interactions are improved due to the inclusion of low content(x=0.1) of Nd^3+and Zn^2+ions into the ***,with further increasing the Nd^3+and Zn^2+contents(x=0.9),the magnetic interactions are weakened.

关键词： Sr hexaferrites Rare earths Mossbauer spectroscopy AC susceptibility ZFC-FC

RATIONAL gENERAL SOLUTIONS OF HIgHER ORDER ALgEBRAIC ODES

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Journal of Systems Science & Complexity 2013年第2期26卷 261-280页

作者： HUAng yanli ng L x Chu WINKLER Franz School of Computer Science and Software Engineering Tianjin Polytechnic University Research Institute for Symbolic Computation(RISC) Johannes Kepler University Department of Mathematics Quy Nhon University

This paper generalizes the method of ng6 and Winkler （2010, 2011） for finding rational general solutions of a first order non-autonomous algebraic ordinary differential equation （AODE） to the case of a higher order AODE, provided a proper parametrization of its solution hypersurface. The authors reduce the problem of finding the rational general solution of a higher order AODE to finding the rational general solution of an associated system. The rational general solutions of the original AODE and its associated system are in computable 1-1 correspondence. The authors give necessary and sufficient conditions for the associated system to have a rational solution based on proper reparametrization of invariant algebraic space curves. The authors also relate invariant space curves to first integrals and characterize rationally solvable systems by rational first integrals.

关键词： Algebraic ODE associated system invariant algebraic space curve rational first integral rational general solution.

Exercise preconditioning alleviates ischemia-induced memory deficits by increasing circulating adiponectin

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Neural Regeneration Research 2025年第5期20卷 1445-1454页

作者： Meifeng Zheng Borui Zhang Sonata S y yau Kwok-Fai So Li Zhang Haining Ou Department of Rehabilitation Medicine Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Medicine The Fifth Clinical College of Guangzhou Medical UniversityGuangzhouGuangdong ProvinceChina Key Laboratory of CNS Regeneration(Ministry of Education) Guangdong-Hong Kong-Macao Institute of CNS RegenerationJinan UniversityGuangzhouGuangdong ProvinceChina Department of Rehabilitation Sciences The Hong Kong Polytechnic UniversityHong Kong Special Administrative RegionChina State Key Laboratory of Brain and Cognitive Science Li Ka Shing Faculty of MedicineThe University of Hong KongHong Kong Special Administrative RegionChina Center for Exercise and Brain Science School of PsychologyShanghai University of SportShanghaiChina Neuroscience and Neurorehabilitation Institute University of Health and Rehabilitation SciencesQingdaoShandong ProvinceChina

Cerebral ischemia is a major health risk that requires preventive approaches in addition to drug *** exercise enhances neurogenesis and synaptogenesis,and has been widely used for functional rehabilitation after *** this study,we determined whether exercise training before disease onset can alleviate the severity of cerebral *** also examined the role of exercise-induced circulating factors in these *** mice were subjected to 14 days of treadmill exercise training before surgery for middle cerebral artery *** found that this exercise pre-conditioning strategy effectively attenuated brain infarct area,inhibited gliogenesis,protected synaptic proteins,and improved novel object and spatial memory *** analysis showed that circulating adiponectin plays a critical role in these preventive effects of *** activation of adiponectin receptors by Adipo Ron mimicked the effects of exercise,while inhibiting receptor activation abolished the exercise *** summary,our results suggest a crucial role of circulating adiponectin in the effects of exercise pre-conditioning in protecting against cerebral ischemia and supporting the health benefits of exercise.

关键词： adiponectin cerebral ischemia exercise pre-conditioning hippocampus memory function middle cerebral artery occlusion prefrontal cortex synaptic proteins treadmill exercise