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Phase Formation and magnetic Properties of Nanocomposite Nd-Fe-B Adjusted by Small Amount of Dy and Co

Journal of Rare Earths 2004年第Z2期22卷 89-94页

作者： T S Jang T W Lim h S Aum D h lee m B Kim Division of materials and Chemical Engineering Sun Moon UniversityKorea Division of Materials and Chemical EngineeringSun Moon UniversityKorea Division of Mechanical EngineeringSun Moon University 100 Kalsan LiTangjung MyonAsan CityChoongnam 336-708Korea Division of Materials and Chemical EngineeringSun Moon UniversityKorea Division of Materials and Chemical EngineeringSun Moon UniversityKorea

In order to improve and stabilize the magnetic properties of nanocomposite Nd2Fe14B/α-Fe magnetic alloys by a compositional adjustment, small amount of Dy and/or Co was added to Nd9Fe84B7 alloys. DTA analysis on the amorphous of the alloys took place as the soft magnetic phases were crystallized, and then the hard magnetic Nd2Fe14B was precipitated from them. While α-Fe and a metastable 1:7 (TbCu7-type) phase were formed simultaneously in Dy and Co-free alloys, they were crystallized separately at different temperatures after Dy or Co was added. This phase separation occurred more clearly in the Dy-treated alloys and the other soft magnetic phase Fe3B was also stabilized by Dy and/or Co. The 1: 7 phase that was stabilized by Dy and/or Co was not eliminated at 700 ℃, decreasing magnetic properties of the alloys. It was eventually disappeared above 725 ℃, but Fe3B was not eliminated even at 750 ℃ when Dy was added more than 0.5 at% or Co was added more than 2.0 at%. Amount of Nd2Fe14B in the alloys tended to increase as Dy addition increased,whereas Co addition did not lead to any appreciable change in the ratio of α-Fe and Nd2Fe14B. moreover, Dy addition apparently increased coercivity of an alloy while Co addition had a beneficial effect on remanence. The grains in the Dytreated alloys were usually finer than those in the Co-treated alloys. The grain size of both α-Fe and Nd2Fe14B in the alloys exhibiting mr ≥ 0.72 was in the range of 20 ～ 40 nm or even larger 50 nm, which is larger than the theoretical optimum size ( ～ 10 nm). Typical magnetic properties obtained from a Nd7.5Dy1.5Fe82.5Co1.5B7 alloy annealed for 12 min at 725 ℃were ihc=4.85 kOe, Br= 11.32 kG, (Bh)max = 15.73 mGOe, and mr=0.73.

关键词： nanocomposite Nd-Fe-B magnetic properties remanence coercivity

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Investigation of Domain Wall Velocity to External Fields for high-Quality Waveguide-Type Periodically Poled LiNbO_(3) Fabrication

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Journal of Rare Earths 2006年第Z1期24卷 131-135页

作者： Soo Woo Kwon Woo Seok Yang h m lee Woo Kyung Kim hang Yong lee Dae ho Yoon Yo Seung Song Department of materials Engineering Hankuk Aviation UniversityGoyang 412-791Korea Nano Bio-Photonics Team Korea Electronics Technology InstituteBundang 463-816Korea Department of Advanced material Engineering Sungkyunkwan UniversitySuwon 440-746Korea

The Ti-doped waveguide-type periodically poled LiNbO_(3)(PPLN)were fabricated and the dependence of domain wall velocity on an external field applied for domain inversion was *** whole polarization reversal process was computer-controlled to regulate domain wall expansion at a feedback time shorter than 5μ*** coercive voltage and several values of excess voltage were applied on 500μm-thick wafers serially connected to a 1-mOhm external resistor which had an effect of the poling current reduction,*** deceleration of domain wall *** domain wall velocity is sensitive to the poling voltage,precisely speaking,to the excess *** domain wall velocities were 28.70,16.02 and 5.75μm·s^(-1)under poling field of 23.5,22.0 and 21.0 kV·mm^(-1),***,average duty cycle of PPLN is about 49.93%.

关键词： periodically poled lithium niobate coerciv field duty cycle domain wall velocity quasi phase matching

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Field Test of Energy Storage System on Urban Transit System

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Journal of Energy and Power Engineering 2010年第11期4卷 52-57页

作者： h.m. lee Advanced EmUResearch Team Korea Railroad Research Institute Uiwang-City Geyonggi-Do 437-757 Korea

The energy storage system charges the energy generated during braking and discharges it again when a vehicle accelerates on urban transit system. The energy storage system is considered to be one of the useful devices for energy storing and recycling. The energy storage system was developed and installed on the test track of Gyeongsan LRT in Korea. This paper presents the test plan and how much energy is saved by the energy storage system through the field test. When the energy storage system is on/off, the energy saving rate is obtained.

关键词： Energy storage system saving energy rats EDLC urban transit system.

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Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 543-562页

作者： h.m.FEIZABAD m.h.YAS Department of mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQm)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQm)

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Anti-obesity effects of fucoidan from Sargassum thunbergii in adipocytes and high fat diet induced obese mice through inhibiting adipogenic specific transcription factor

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Food Science and human Wellness 2024年第3期13卷 1608-1616页

作者： hyo-Geun lee h.h.A.C.K.Jayawardhana Fengqi Yang D.P.Nagahawaththa N.m.Liyanage Kyung-mo Song Yun-Sang Choi Seung-hong lee You-Jin Jeon min-Cheol Kang Department of marine Life Sciences Jeju National UniversityJeju 63243Republic of Korea marine Science Institute Jeju National UniversityJeju 63333Republic of Korea Research Group of Food Processing Korea Food Research InstituteWanju 55365Republic of Korea Department of Pharmoceutical Engineering Soonchunhyang UniversityAsan 31538Republic of Korea

The prevalence of obesity has increased and is a health concern *** to the concerns regarding synthetic anti-obesity treatments,nowadays natural products become a *** studies proved that there is a potential to use marine algae as anti-obesity ***,in this study,the lipid inhibitory effect of crude polysaccharide of amyloglucosidase-assisted hydrolysate from Sargassum thunbergii(STAC)and its fucoidan fractions(STAFs)on 3T3-L1 cells and high-fat diet(hFD)-induced obese mice were *** to the results,the STAF3,showed the highest xylose content and exhibited significant inhibitory effects on lipid accumulation by downregulating adipogenic and lipogenic proteins in 3T3-L1 ***,oral supplementation with STAC significantly declined gain in body weight and fat weight,and serum lipid contents in an hFD-induced obesity mouse *** and chemical characterizations demonstrated that puritied STAF3 has consistent surface morphology and small particle size,with similar structural characteristics as commercial ***,these results indicate that STAC and purified STAF3 from Sargassum thunbergia is a potent source to develop as ananti-obesity agents or functional food products to counter obesity.

关键词： Sargassum thunbergii Fucoidan Anti-obesity Anti-steatosis

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基于视觉的食品包装生产线机器人控制系统

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电气传动 2000年第1期30卷 27-30页

作者：吴成东 m.h.lee 沈阳建工学院英国威尔士大学

本文介绍一种食品包装生产线的机器人控制系统。基于视觉系统获得生产线上被包装物体的位置与几何信息，利用惯量分析原理确定抓取点，采用矢量控制与学习控制方法调节机器人抓取器对物体实施稳定抓取。仿真及实验结果证明了控制策略的... 详细信息

本文介绍一种食品包装生产线的机器人控制系统。基于视觉系统获得生产线上被包装物体的位置与几何信息，利用惯量分析原理确定抓取点，采用矢量控制与学习控制方法调节机器人抓取器对物体实施稳定抓取。仿真及实验结果证明了控制策略的有效性。

关键词：食品包装生产线机器人控制系统视觉

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Superplasticity of fine-grained mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.Jeong S.W.lee W.J.Kim Department of materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the hCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

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Nonuniform Dependence on the Initial Data for Solutions of Conservation Laws

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Communications on Applied mathematics and Computation 2024年第1期6卷 489-500页

作者： John m.holmes Barbara lee Keyfitz Department of mathematics The Ohio State UniversityColumbusOH43210USA

In this paper,we study systems of conservation laws in one space *** prove that for classical solutions in Sobolev spaces h^(s),with s>3/2,the data-to-solution map is not uniformly *** results apply to all nonlinear s... 详细信息

关键词： Conservation laws Data-to-solution map Nonuniform dependence

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Pelleting and particle size reduction of corn increase net energy and digestibility of fiber,protein,and fat in corn-soybean meal diets fed to group-housed pigs

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Journal of Animal Science and Biotechnology 2024年第4期15卷 1751-1760页

作者： Su A lee Diego A.Rodriguez Chad B.Paulk hans h.Stein Department of Animal Sciences University of IllinoisUrbanaIL 61801USA Department of Grain Sciences and Industry Kansas State UniversityManhattanKS 66506USA

Background Reduction of the particle size of corn increases energy digestibility and concentrations of digestible and metabolizable *** may also reduce particle size of grain,but it is not known if there are interactions between particle size reduction and *** objective of this experiment was to test the hypothesis that particle size reduction and pelleting,separately or in combination,increase N balance,apparent total tract digestibility(ATTD)of fiber and fat,and net energy(NE)in corn-soybean meal diets fed to group-housed *** Six corn-soybean meal-based diets were used in a 3×2 factorial design with 3 particle sizes of corn(i.e.,700,500,or 300μm)and 2 diet forms(i.e.,meal or pelleted).Pigs were allowed ad libitum access to feed and ***-four castrated male pigs(initial weight:29.52 kg;standard diviation:1.40)were allotted to the 6 diets using a 6×6 Latin square design with 6 calorimeter chambers(i.e.,4 pigs/chamber)and 6 *** consumption and CO_(2)and Ch_(4)productions were measured during fed and fasting states and fecal and urine samples were *** Regardless of particle size of corn,the ATTD of gross energy(GE),N,and acid-hydrolyzed ether extract(AEE),and the concentration of NE were greater(Phan in meal *** of diet form,the ATTD of GE,N,and AEE,and the concentration of NE were increased(linear;Phe particle size of corn,but the increase was greater in meal diets than in pelleted diets(interaction;Ph pelleting and reduction of corn particle size increased nutrient digestibility and NE,but increases were greater in meal diets than in pelleted diets.

关键词： Corn Digestibility Feed technology Net energy Particle size Pelleting

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外周神经鞘瘤：常规及扩散加权mRI鉴别良恶性

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国际医学放射学杂志 2021年第3期44卷 365-366页

作者： J.S.Yun m.h.lee S.m.lee J.S.lee h.J.Kim S.J.lee 赵大伟

摘要目的评价常规mRI及扩散加权成像(DWI)鉴别良恶性外周神经鞘瘤(PNST)的价值。方法 2014年9月—2017年12月收集83例经病理证实的、躯干或四肢良恶性

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