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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

Regional Innovation System: Theoretical Approach and Empirical Study of ChinaAPPROACH AND EMPIRICAL STUDy OF CHINA

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Chinese Geographical Science 2003年第3期13卷 193-198页

作者： liushu-guang CHENCai SchoolofEconomics OceanUniversityofChinaQingdao266071P.R.China CollegeofUrbanandEnvironmentalSciences NortheastNormalUniversityChangchun130024P.R.China

Regional innovation system (RIS) is the new research field of modern economicgeography in the age of knowledge economy. Based on the researches of regional economic geography,the authors of the paper consider RIS as the integrated and interactive systems with innovationmilieu, elements, units, structure and functions. Five aspects of evaluation indicators includinginnovation input scale and output scale, innovation milieu transition, innovation inner operation,as well as innovation outer impact are worked out for final indicators of RIS scale and *** to different RIS situations, three patterns of independent, imitative and cooperativedevelopment are put forward for choosing. At the latter part of the paper, we select 12 provincialregions (including three municipalities and one autonomous region) of China for empirical study. Theresults show that there exists great difference among each region from the aspects of innovationscale and quality mainly owning to the diversification of RIS social and economic milieu, the majorinnovative units of enterprises, universities and R&D institutes. Finally, the paper points out theinnovation development decisions for each region.

关键词： regional innovation system theory methods cases of China

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

A LATTICE BOLTZMANN SUBGRID MODEL FOR LID-DRIVEN CAVITy FLOW

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Journal of Hydrodynamics 2005年第3期17卷 289-294页

作者： y.ngFan liushu-hong WUyu-lin TAngXue-lin DepartmentofThermalEngineering TsinghuaUniversityBeijing100084China DepartmentofHydraulicEngineering TsinghuaUniversityBeijing100084China

In recent years, the Lattice Boltzmann Method (LBM) has developed into an alternative and promising numerical scheme for simulating fluid flows and modeling physics in fluids. In order to propose LBM for high Reynolds number fluid flow applications, a subgrid turbulence model for LBM was introduced based on standard Smagorinsky subgrid model and Lattice Bhatnagar-Gross-Krook (LBGK) model. The subgrid LBGK model was subsequently used to simulate the two-dimensional driven cavity flow at high Reynolds numbers. The simulation results including distribution of stream lines, dimensionless velocities distribution, values of stream function, as well as location of vertex center, were compared with benchmark solutions, with satisfactory agreements.

关键词： Lattice Boltzmann Method (LBM) Lattice Bhatnagar-Gross-Krook (LBGK) model Smagorinsky subgrid model driven cavity flow

Synthesis and Molecular Structure of a C-iso-Butyl-cavitand Bowl with Trimethyl and Methylol Groups

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Chinese Journal of Structural Chemistry 2005年第4期24卷 444-448页

作者： liushu-Qun yAOWen-Rui ZHAngQian-Feng DepartmentofAppliedChemistry SchoolofChemicalEngineeringandChemistryAnhuiUniversityofTechnologyMaanshanAnhui243002China

A C-iso-butyl-cavitand bowl with trimethyl and methylol groups was isolated from the acetoxymethyl hydrolysis of mono-methylbromo-cavitand in THF. The molecular structure of the present cavitand compound was determined by single-crystal X-ray diffraction. The compound (C56H70N2O9) crystallizes in orthorhombic, space group Pnma with a = 19.5060(15), b = 19.8136(15), c = 12.9508(10) ?, V = 5005.3(7) ?3, Z = 4, Mr = 915.14, Dc = 1.214 g/cm3, F(000) = 1968, μ = 0.081 mm?1, S = 1.012, the final R = 0.0789 and wR = 0.1488 for 2298 observed reflections with I > 2σ(I) and 322 variable parameters. The structure exhibits a rigid bowl-cavity with an available functional hydroxyl group. The bowl of cavitand contains a CH3CN solvent molecule, and the depth of the bowl-shaped cavity is ca. 2.42 ?.

关键词： structure resorcinarene cavitand supramolecular chemistr

Adaptive Response of Thymocyte Apoptosis and Cell Cycle Progression Induced by Low Dose X-Ray Irradiation in Mice^1

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Biomedical and Environmental Sciences 2000年第3期13卷 180-188页

作者： GOngSHOU－LIAng liushu－CHUN DepartmentofRadiationBiology NormanBethuneUniversityofMedicalSciences8XinminStreetChangchun130021China DepartmentofRadiationBiology NormanBethuneUniversityofMedicalSciences8Xi

The dose_effect of adaptive response of thymocyte apoptosis and cell cycle progression induced by whole_body X_ray irradiation (WBI) was studied in male Kunming mice. The inductive doses (D\-1) were 25, 50, 75, 100 or 200 mGy 6 h before the challenging doses (D\-2) of 1.0, 1.5 or 2.0 Gy. The changes in the percentages of the thymocyte apoptotic bodies (TAB) and the cells in different phases of cell cycle were measured with flow cytometry. The percentages of TAB decreased, the arrests of G\-1 and G\-2+M phases diminished, and the cells of DNA synthesis of S phase increased when the D\-1+D\-2 groups was compared with the D\-2 groups. When D\-1 was 200 mGy, the adaptive response of thymocyte apoptosis and cell cycle progression were no longer induced by low dose radiation (LDR). In addition, the extracellular fluid from the splenocytes were cultured with Con A for 48 h \%in vitro\% 24 h after 75 mGy WBI was placed in the murine thymocyte suspension from mice irradiated with 2.0 Gy WBI and co_incubated. The thymocyte apoptosis decreased. Especially, noteworthy was that the percentages of TAB after the incubation for 72 h were significantly lower than those in 2.0 Gy irradiated thymocytes (\%P\%y (D\-1, 12.5 mGy/min) 6 h before 1.0_2.0 Gy (D\-2, 0.287 Gy/min) exposure, an adaptive response of thymocyte apoptosis and cell cycle progression may be induced under the condition of WBI, and LDR (75 mGy) may change the microenvironment of immune cells and decrease the thymocyte apoptosis.

关键词：小鼠低剂量X线照射诱导胸腺细胞凋亡细胞周期进展适应性适应

Microscopic Mechanism of Large Fluctuation in Odd-Even Differences in Moments of Inertia for Actinide Nuclei

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Communications in Theoretical Physics 2005年第2期43卷 287-294页

作者： yULei GOngLun-Xun liushu-Xin ZEngJin-yan DepartmentofPhysics PekingUniversityBeijing100871China／／DepartmentofPhysicsGuizhouNormalUniversityGuiyang550001China DepartmentofPhysics PekingUniversityBeijing100871China

The experimental large fluctuation in odd-even differences in moments ofinertia of deformed actinide nuclei is investigated using the particle-number conserving (PNC)method for treating the cranked shell model with monopole and quadrupole pairing interactions. PNCcalculations show that the large odd-even difference in moments of inertia mainly comes from theinterference contributions j(μv) from particles in high j intruder orbitals μ and v quite near theFermi surface, which have no counterpart in the BCS formalism. The effective monopole andquadrupole pairing interaction strengths are determined to fit the experimental odd-even differencesin binding energies and bandhead moments of inertia. The experimental results for the variation ofmoments of inertia with rotational frequency ω are reproduced well by the PNC calculation. Thenearly identical experimental moments of inertia between ~(236)U(gsb) and ~(238)U(gsb) at lowfrequencies hω ≤ 0.20 MeV are also reproduced quite well.

关键词： odd-even differences in moments of inertia cranked shell model particle-number conserving treatment

AN IMPROVED DyNAMIC SUBGRIDSCALE STRESS MODEL

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Journal of Hydrodynamics 2004年第3期16卷 276-282页

作者： TAngXue-ling QIANZhong-dong WUyu-lin liushu-hong y.ngFan DepartmentofThermalEngineering TsinghuaUniversityBeijing100084China

According to modeling principle that a model must be more accurate ifincluding more flow information, and based on the Cauchy-Helmholtz theorem and the Smagorinskymodel, a second-order dynamic model with double dynamic coefficients was proposed by apply.ngdimension analyses. The Subgrid-Scale (SGS) stress is a function of both strain-rate tensor androtation-rate tensor. The SIMPLEC algorithm and staggering grid system was applied to give thesolution of the discretized governing equations, and for the turbulent flow through a 90° bend, thedistributions of velocity and pressure were achieved. The comparison between experimental data andsimulation results at a Reynolds- number 40000 shows a good agreement and implies that this model ispracticable and credible.

关键词： sub-grid-scale (SGS) model second-order dynamic model large eddy simulation( LES) turbulent flow curved duct

Classification and Assessment of Freeze-Thaw Erosion in Tibet, China

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Wuhan University Journal of Natural Sciences 2005年第4期10卷 635-640页

作者： ZHAngJian-guo y.ngy.ng-hong liushu-zhen InstituteofMountainHazardsandEnvironment ChineseAcademyofSciencesChengdu610041SichuanChina SchoolofCivilEngineering SouthwestJiaotongUniversityChengdu610031SichuanChina

Based on the analysis of existing relevant research result, a theoretical basis for the defining freeze- thaw erosion zones of Qinghai-Tibet Plateau was been put forward, and a equation for calculating the altitude of the lower bound of the freeze-thaw erosion zones of Qinghai-Tibet Plateau was been established in this paper. Moreover, the freeze-thaw erosion zones in Tibet was been identified by using Geographical Information System (GIS) software. Next, based on the comprehensive analysis of impact factors of freeze-thaw erosion, this paper chooses annul temperature range, slop and vegetation as three indexes, works out the criteria for relative classification of freeze-thaw erosion, and realizes the relative classification of the freeze-thaw erosion in Tibet under the support of GIS software. Then, a synthetic assessment of freeze-thaw erosion in Tibet was been done according to the relative classification result.

关键词： Key words freeze thaw erosion Tibet assessment