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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 hat.h *** 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 hat.h 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

Performance Analysis of Mini Centrifugal Pump with Splitter Blades

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Journal of thermal Science 2013年第6期22卷 573-579页

作者： t. Shigemitsu J. Fukutomi t. Wada h. Shinohara Institute of technology and Science The University of Tokushima 2-1 Minamijosanjima-cho Tokushima 770-8506Japan Graduate School of Advanced technology and Science The University of Tokushima 2-1 Minamijosanjima-choTokushima 770-8506 Japan

Design method for a mini centrifugal pump is not established because the internal flow condition for these small-sized fluid machines is not clarified and conventional theory is not suitable for small-sized pumps. then, a semi-open impeller for the mini centrifugal pump with 55mm impeller diameter is adopted in this research to take simplicity and maintenance into consideration. Splitter blades are adopted in this research to improve the performance and internal flow condition of mini centrifugal pump having large blade outlet angle. the performance tests are conducted with these rotors in order to investigate the effect of the splitter blades on the performance and internal flow condition of the mini centrifugal pump. A three dimensional steady numerical flow analysis is conducted to analyze rotor, volute efficiency and loss caused by a vortex. It is clarified from the experimental results that the performance of the mini centrifugal pump is improved by the effect of the splitter blades. Flow condition at outlet of the rotor becomes uniform and back flow regions are suppressed in the case with the splitter ***, the volute efficiency increases and the vortex loss decreases. In the present paper, the performance of the mini centrifugal pump is shown and the flow condition is clarified with the results of the experiment and the numerical flow analysis. Furthermore, the performance analyses of the mini centrifugal pumps with and without the splitter blades are conducted.

关键词： Centrifugal pump Performance Internal flow Splitter blade

Correlations between IMC thickness and three factors in Sn-3Ag-0.5Cu alloy system

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中国有色金属学会会刊：英文版 2007年第4期17卷 686-690页

作者：孟工戈 t. takemoto h. Nishikawa College of Materials Science and Engineering Harbin University of Science and Technology Joining and Welding Research Institute Osaka UniversityIbalaki Osaka 567-0047 Japan

the effects of Ni content, soldering temperature and time on the IMC thickness in Sn-3Ag-0.5Cu and Sn-3Ag-0.5Cu-0.2Co alloys were researched using uniform design method and computer programs. For each alloy, the factors were divided into three levels in the experiment. two correlative equations are given by regression. they indicate that the effects of three factors on the function are in the mutual and quadratic forms. And the analysis of variance shows the equations are sound and meaningful. Using the equations, it is easy to search, predict and control the IMC thickness. the existence of element Co accelerates the crystallization and growing up of IMC.

关键词：锡银铜合金无铅焊料金属间化合物厚度均匀设计

Characteristics of the Mach Disk in the Underexpanded Jet in which the Back Pressure Continuously Changes with time

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Journal of thermal Science 2003年第2期12卷 132-137页

作者： t.Irie t.Yasunobu h.Kashimura t.Setoguchi Department of Mechanical Engineering Kitakyushu National College of TechnologyShiiKokuraminami-kuKitakyushu 802-0985JapanDepartment of Control and Information Systems EngineeringKitakyushu National College of TechnologyShiiKokuraminami-kuKitakyushu 802-0985JapanDepartment of Control and Information Systems EngineeringKitakyushu National College of TechnologyShiiKokuraminami-kuKitakyushu 802-0985JapanDepartment of Mechanical EngineeringSaga UniversityHonjoSaga 840-8502Japan

When the high-pressure gas is exhausted to the vacuum chamber from the nozzle,the underexpanded supersonic jet contained with the Mach disk is generally *** eventual purpose of this study is to clarify the unsteady phenomenon of the underexpanded free jet when the back pressure continuously changes with *** characteristic of the Mach disk has been clarified in consideration of the diameter and position of it by the numerical analysis in this *** sonic jet of the exit Mach number Me=1 is assumed and the axisymmetric conservational equation is solved by the tVD method in the numerical *** diameter and position of the Mach disk differs with the results of a steady jet and the influence on the continuously changing of the back pressure is evidenced from the comparison with the case of steady supersonic jet.

关键词： underexpanded jet sonic jet regular reflection Mach reflection Mach disk tVD method.

Recrystallization behaviour of fine-grained magnesium alloy after hot deformation

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中国有色金属学会会刊：英文版 2007年第6期17卷 1139-1142页

作者：杨续跃 h. Miura t. Sakai School of Materials Science and Engineering Central South University Department of Mechanical Engineering and Intell igent Systems UEC Tokyo Tokyo 182-8585 Japan Department of Mechanical Engineering and Intell igent Systems UEC Tokyo Tokyo 182-8585 JapanYANGXu-yue

Annealing behaviors of hot-deformed magnesium alloy AZ31 were studied at temperatures from 300 to 673 K by optical and SEM/EBSD metallographic observation. temperature dependence of the average grain size(D) is categorized into three temperature regions, i.e. an incubation period for grain growth, rapid grain coarsening, and normal grain growth. the number of fine grains per unit area, however, is reduced remarkably even in incubation period. this leads to grain coarsening taking place continuously in the whole temperature regions. In contrast, the deformation texture scarcely changes even after full annealing at.high temperatures. It is concluded that the annealing processes operating in hot-deformed magnesium alloy with continuous dynamic recrystallized grain structures can be mainly controlled by grain coarsening accompanied with no texture change, that is, continuous static recrystallization.

关键词：镁合金退火连续再结晶晶体生长纹理

Enhancing blocking temperature using inverse hydrogen bonds for non-radical bridged dimeric Dy(Ⅲ)single-molecule magnets

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Science China Chemistry 2024年第10期67卷 3328-3338页

作者： Peng-Bo Jin Qian-Cheng Luo ye-ye Liu Yan-Zhen Zheng Frontier Institute of Science and technology State Key Laboratory of Electrical Insulation and Power EquipmentMOE Key Laboratory for Nonequilibrium Synthesis and Modulation of Condensed MatterXi’an Key Laboratory of Electronic Devices and Material Chemistry and School of ChemistryXi’an Jiaotong UniversityXi’an 710054China

Single-molecule magnets(SMMs)are a kind of nanosized magnetic materials that are capable of storing massive bytes of *** coupling the spin centers in a proper manner is a usual approach to promote the working temperature(or blocking temperature)for *** delocalized radicals have been widely employed to accomplish this ***,we show a new manner by using weak but multiple B–h^(δ-)···Dy^(3+)inverse hydrogen bonding(IhB)interactions to control the magnetic couplings in a series of dimeric dysprosiacaborane *** approach leads to a record high t_(B)^(100s)of 10 K among non-radical bridged dimeric SMMs,which is mainly ascribed to strong ferromagnetic coupling(4.38 cm^(-1))and the proper alignment of the magnetic principle axes of the adjacent dysprosium(Ⅲ)*** verifying by theoretical calculations,these results demonstrate that IhB interactions can be used to construct strong axial ferromagnetic coupling and enhancing magnetic blocking temperature for SMMs.

关键词： single-molecule magnets carborane dysprosium ferromagnetic coupling inverse hydrogen bond

theoretical Study on Photoisomerization of 2-Methylfuran to 3-Methylfuran

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Chinese Journal of Structural Chemistry 2006年第6期25卷 681-688页

作者： WANG Yan-Xia ye Song Department of Chemistry Yunnan University Kunming 650091 China

In the present work, the photoisomerization of 2-methylfuran to 3-methylfuran is investigated with the complete active space SCF （CASSCF） molecular orbital method. Geometries of minima and transition states on the excited and ground states are fully optimized at the CAS level with a 6-3 IG＊ basis set. A multireference MP2 algorithm that.has been implemented in Gaussian is used to correct the energetics for dynamic correlation. the topology and reaction funnels of the singlet, triplet （S0, t1, t2） and potential energy surfaces have been characterized along the reaction coordinates corresponding to the mechanism. the reaction proceeds via two diradical intermediates, one intermediate product and four transition states. the two diradical S 1/t2 and t1/S0 energy surface crossing points are located along the reaction path and a t1/t2 conical intersection is also located. From this point the reaction soon returns to t1 surface. It is the most reasonable that the intersystem crossing from t1 to S0 takes place.

关键词： CASSCF photoisomerization intersystem crossing point reaction path

Programmable and reconfigurable humidity-driven actuators made with MXene(ti_(3)C_(2)t_(x))-cellulose nanofiber composites for biomimetic applications

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Nano Research 2024年第7期17卷 6619-6629页

作者： Shaofeng Zeng Yuanji ye Peidi Zhou Shimin Yi Qiaohang Guo huamin Chen Guozhen Shen Mingcen Weng School of Mechanical and Automotive Engineering Fujian University of TechnologyFuzhou 350118China School of Materials Science and Engineering Fujian Provincial Key Laboratory of Advanced Materials Processing and ApplicationKey Laboratory of Polymer Materials and Products of Universities in FujianFujian University of TechnologyFuzhou 350118China Institute of Smart Marine and Engineering Fujian University of TechnologyFuzhou 350118China Fujian Key Laboratory of Functional Marine Sensing Materials College of Materials and Chemical EngineeringMinjiang UniversityFuzhou 350108China School of Integrated Circuits and Electronics Beijing Institute of TechnologyBeijing 100081China

Smart actuators have a wide range of applications in bionics and energy *** ability to reconfigure shape is essential for soft actuators to achieve various shapes and deformations,which is a crucial feature for next-generation ***,it is still an enormous challenge to establish a straightforward approach to creating programmable and reconfigurable ***-cellulose nanofiber composite film(MCCF)with a brick-and-mortar hierarchical structure was produced through a vacuum filtration *** demonstrates impressive mechanical properties such as a tensile stress of 68 MPa and a Young’s modulus of 4.65 ***,the MCCF highlights its potential for water-assisted shaping/welding due to the abundance of hydrogen bonds between MXene and cellulose *** also showcases capabilities as a humiditydriven actuator with a rapid response rate of 550°·s^(−1).Using the methods of water-assisted shaping/welding,several bionic actuators(such as flower,butterfly,and muscle)based on MCCF were designed,highlighting their versatility in applications of smart *** research showcases the impressive capabilities of MXene-based actuators and offers beneficial insights for the advancement of future intelligent materials.

关键词： MXene cellulose nanofibers programmable actuators humidity-driven

Facile synthesis of intra-nanogap enhanced Raman tags with different shapes

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Nano Research 2024年第9期17卷 8415-8423页

作者： Sanjun Fan Brian t.Scarpitti Zhewen Luo Abigail E.Smith Jian ye Zachary D.Schultz Department of Chemistry and Biochemistry The Ohio State UniversityColumbusOhio 43210USA School of Biomedical Engineering Shanghai Jiao Tong UniversityShanghai 200030China

hot spot engineering in plasmonic nanostructures plays a significant role in surface-enhanced Raman scattering(SERS)for bioanalysis and cell ***,creating stable,reproducible,and strong SERS signals remains challenging due to the potential interference from surrounding chemicals and locating SERS-active analytes into hot-spot ***,we developed a straightforward approach to synthesize intra-gap nanoparticles encapsulating 4-nitrobenzenethiol(4-NBt)as a reporter molecule within these gaps to avoid outside *** made three kinds of intra-gap nanoparticles using nanorods,bipyramids,and nanospheres as cores,in which the nanorods based intra-gap nanoparticles exhibit the highest SERS *** advantage of our method is the ease of preparation of high-yield and stable intra-gap nanoparticles characterized by a short incubation time(10 min)with 4-NBt and quick synthesis without requiring an additional step to centrifuge for the purification of core *** intense localized field in the synthesized hot spots of these plasmonic gap nanostructures holds great promise as a SERS substrate for a broad range of quantitative optical applications.

关键词： hot spot engineering surface enhanced Raman scattering intra-gap nanoparticles 4-nitrobenzenethiol

Biological transformation,kinetics and dose-response assessments of bound musk ketone hemoglobin adducts in rainbow trout as biomarkers of environmental exposure

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Journal of Environmental Sciences 2008年第7期20卷 878-884页

作者： M A Mottaleb J h Zimmerman t W Moy Department of Chemistry and Biochemistry Baylor UniversityP.O.Box 97348WacoTX 76798USA. U.S.Environmental Protection Agency National Exposure Research LaboratoryEnvironmental Sciences Division944 East Harmon AveLas VegasNV 89119USA

Low levels (ng/g) of musk ketone (MK),used as a fragrance additive in the formulation of personal care products,are frequently detected in the water and other ***,aquatic organisms can be continuously exposed to *** this study,kinetics and dose-response assessments of 2-amino-MK (AMK) metabolite,bound to cysteine-hemoglobin (hb) in rainbow trout,formed by enzymatic nitro-reduction of MK have been *** were exposed to a single exposure of 0.010,0.030,0.10,and 0.30 mg MK/g ***...

关键词： biotransformation kinetics hemoglobin adducts dose-response nitro musks biomarker fish