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Effect of Sub-T_g Annealing on the Corrosion Resistance of the Cu–Zr Amorphous Alloys

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Acta Metallurgica Sinica(English Letters) 2018年第3期31卷 273-280页

作者： Sang-Soo Shin Hong-Kyu Kim Jae-Chul Lee ik-min park Department of Materials Science and Engineering Pusan National University Advanced Analysis Center Korea Institute of Science and Technology Department of Materials Science and Engineering Korea University

Despite the economy of material cost and excellent toughness of Cu-based amorphous alloys,especially CusoZrso,their poor corrosion resistance to a chloride medium limits their widespread *** this study,corrosion tests were performed on the CusoZrso amorphous alloy with different degrees of short-range order,which were prepared by annealing below the glass transition temperature（Tg）.It was found that the corrosion resistance of amorphous alloys is improved to a significant level when the alloys were heated below *** studies showed that thermally activated relaxation process of created disorder,which occurs during sub-Tg annealing,is responsible for the improvement in the corrosion *** dynamics simulations performed on the Cu-Zr amorphous alloys demonstrated that the relaxation process of the alloys is associated with the formation of energetically stable icosahedra and icosahedron-like *** study highlights the effects of sub-Tg annealing on the improvement in the corrosion resistance of the amorphous alloys from the viewpoint the relaxation process of the short-range orders.

关键词： Amorphous alloys Corrosion Annealing Molecular dynamics Electrochemical performance

Effect of solution treatment and artificial aging on microstructure and mechanical properties of Al-Cu alloy

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Transactions of Nonferrous Metals Society of China 2013年第3期23卷 631-635页

作者： Jae-Ho JANG Dae-Geun NAM Yong-Ho park ik-min park Korea Institute of Industrial Technology Busan 618-230Korea School of Material Science and Engineering Pus an National UniversityBusan 609-735Korea

In order to achieve good mechanical properties of Al-Cu alloys such as high strength and good toughness,precipitation hardening and artificial aging treatment were *** defined by the T6 heat treatment,the standard artificial aging treatment for Al-Cu alloy followed heat treatments of solution treatment at 510-530 ℃ for 2 h,quenching in water at 60 ℃ and then artificial aging at 160-190 ℃ for 2-8 *** effects of solution treatment and artificial aging on the microstructure and mechanical properties of Al-Cu alloy were studied by optical microscopy（OM）,scanning electron microscopy（SEM）,energy dispersive X-ray spectroscopy（EDS）,transmission electron microscopy（TEM） and tensile *** results of solution treatment indicate that the mechanical properties of Al-Cu alloy increase and then decrease with the increase of solution *** is because the residual phases dissolve gradually into the matrix,and the fraction of the precipitation and the size of the re-crystallized grain *** to the solution temperature,the solution holding time has less effect on the microstructure and the mechanical properties of Al-Cu *** artificial aging treatments were conducted at 160-180 ℃ for 2-8 *** results show that the ultimate tensile strength can be obtained at 180 ℃ for 8 *** tensile strength increased with increasing time or *** strength was found as the same as the ultimate tensile strength result.

关键词： Al-Cu alloy solid solution treatment artificial aging microstructure mechanical property

Ce对铸造Mg-5Al-2Si合金中Mg2Si相改性及力学性能的影响

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铸造 2019年第7期68卷 679-683页

作者：朱文杰李德江曾小勤 Seul Bi Lee ik min park 上海交通大学材料科学与工程学院上海200240 釜山国立大学韩国釜山46287

利用X射线衍射、光学显微镜和扫描电镜等分析测试手段,研究了不同Ce添加量对重力铸造Mg-5Al-2Si合金显微组织和力学性能的影响规律。结果表明,添加Ce以后,合金中主要存在α-Mg相、汉字状Mg2Si相、多边形Mg2Si相、细小的Al11Ce3和CeSi2相... 详细信息

利用X射线衍射、光学显微镜和扫描电镜等分析测试手段,研究了不同Ce添加量对重力铸造Mg-5Al-2Si合金显微组织和力学性能的影响规律。结果表明,添加Ce以后,合金中主要存在α-Mg相、汉字状Mg2Si相、多边形Mg2Si相、细小的Al11Ce3和CeSi2相;稀土Ce的加入改变了合金中Mg2Si相的尺寸、形貌与分布;随着Ce含量增加,汉字状Mg2Si相的平均长度大幅度减小,共晶Mg2Si相的形貌由粗大的汉字状转变为多边形状;当Ce添加量为0.4%时,试验合金的力学性能达到最佳,而增加至0.8%时,合金的力学性能反而下降。拉伸断口形貌也揭示了合金的力学性能情况。因此,适当的Ce添加量(0.4%)可以有效地改性Mg2Si相,从而提高合金的强度和伸长率。

关键词：耐热镁合金 Mg-Al-Si系合金汉字状Mg2Si相显微组织力学性能

Electrochemically Deposited CZTSSe Thin Films for Monolithic Perovskite Tandem Solar Cells with Efficiencies Over 17%

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Energy & Environmental Materials 2024年第1期7卷 147-152页

作者： Sun Kyung Hwang ik Jae park Se Won Seo Jae Hyun park So Jeong park Jin Young Kim Department of Materials Science and Engineering Seoul National UniversitySeoul 08826Korea Department of Applied Physics Sookmyung Women's UniversitySeoul 04310Korea Research Institute of Advanced Materials and Systems Sookmyung Women's UniversitySeoul 04310Korea Research Institute of Advanced Materials(RIAM) Seoul National UniversitySeoul 08826Korea

In spite of the high potential economic feasibility of the tandem solar cells consisting of the halide perovskite and the kesterite Cu2ZnSn(S,Se)4(CZTSSe),they have rarely been demonstrated due to the difficulty in implementing solution-processed perovskite top cell on the rough surface of the bottom ***,we firstly demonstrate an efficient monolithic two-terminal perovskite/CZTSSe tandem solar cell by significantly reducing the surface roughness of the electrochemically deposited CZTSSe bottom *** surface roughness(R_(rms))of the CZTSSe thin film could be reduced from 424 to 86 nm by using the potentiostatic mode rather than using the conventional galvanostatic mode,which can be further reduced to 22 nm after the subsequent ion-milling *** perovskite top cell with a bandgap of 1.65 eV could be prepared using a solution process on the flattened CZTSSe bottom cell,resulting in the efficient perovskite/CZTSSe tandem solar *** the current matching between two subcells involving the thickness control of the perovskite layer,the best performing tandem device exhibited a high conversion efficiency of 17.5%without the hysteresis effect.

关键词： CZTSSe monolithic tandem solar cells perovskite solution process surface roughness control

Evaluation of the safety of anterior capsule staining with trypan blue under air: a retrospective analysis

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International Journal of Ophthalmology(English edition) 2022年第3期15卷 432-437页

作者： Young min park Jong Soo Lee Ji Eun Lee Yeon Ji Jo ik Soo Byon Sung Who park Centum Bright Light Eye Clinic 20Centum 2-roHaeundaeguBusanKorea 48060Republic of Korea Department of Ophthalmology School of MedicinePusan National University and Medical Research InstitutePusan 49241Republic of Korea

AIM: To evaluate the safety of using 0.03% trypan blue under air for anterior capsule staining in cataract ***: The current study involved a retrospective analysis of the medical records of 86 patients with vitreous hemorrhage, who underwent pars plana vitrectomy and cataract *** patients were classified into two *** trypan blue group(n=45) comprised patients who underwent anterior capsule staining with 0.03% trypan blue under an air *** control group(n=41) comprised of patients who underwent intracameral illuminator-assisted *** status of endothelial cell density(ECD) in both the groups was ***: The trypan blue group displayed significant decline in ECD at 1 mo(7.91% loss, P<0.001) and 3 mo(9.65% loss, P<0.001) after the surgery, whereas no significant changes were observed in the control ***, the number of patients who did not display a postoperative decline in ECD was significantly higher in the control group(43.9%;18 patients) than in the trypan blue group(17.1%;7 patients, P=0.004).CONCLUSION: Anterior capsule staining with trypan blue under the air bubble would not be as safe as the intracameral *** ECD loss might be attributed to the air bubble rather than to the deleterious effects of 0.03% trypan *** studies are required to clarify this.

关键词： anterior capsule cataract endothelium trypan blue vitreous hemorrhage

Development and Experimental Evaluation of Strip Shape Prediction Model for Sendzimir Rolling Mills

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Journal of Iron and Steel Research International 2013年第12期20卷 25-32页

作者： SHIN Jong-min HAN Seong-ik KIM Jong-shik School of Mechanical Engineering Pusan National University School of Electrical Engineering Pusan National University

It is difficult to obtain the desired strip shape using Sendzimir rolling mills because small diameter work rolls can be easily deformed by the roiling force. To control the strip shape effectively, it is important to understand the relationship between the behavior of the shape actuator and the variation of the strip shape. A numerical model based on the contact element method was proposed for the prediction of strip shape. In this numerical model, the re- lationships between the actuating forces, the roll deflections, the thickness profiles of the entry and exit sides, and the strip shape were considered. The proposed numerical model for strip shape prediction was evaluated by computer simulation and experiment with respect to various AS-U roll and first intermediate roll positions.

关键词： Sendzimir rollingmill double acting AS-U roll strip shape prediction model contact element method

Improvement of Shape Recognition Performance of Sendzimir Mill Control Systems Using Echo State Neural Networks

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Journal of Iron and Steel Research International 2014年第3期21卷 321-327页

作者： Jung-hyun park Seong-ik HAN Jong-shik KIM School of Mechanical Engineering Pusan National University School of Electrical Engineering Pusan National University

High rigidity twenty-high Sendzimir mills （ZRMs） are widely used for rolling stainless steels, silicon sheets, etc. A ZRM uses a small diameter work roll to produce massive rolling forces. Since a work roll with a small diameter can be bent easily, strips often have complex shapes with mixed quarter and deep edge waves in the shape of plates. In order to solve this problem, fuzzy neural network controls are generally used for shape： recognition in ZRM control systems. Among various neural network types, the multi-layer perceptron （MLP） is typically used in current ZRMs. However, an MLP causes the loss of a large amount of shape recognition data. To improve the shape recognition per- formance of ZRM control systems, echo state networks （ESNs） are proposed to be used. Through simulation re- sults, it is found that shape recognition performance could be improved using the proposed ESN method.

关键词： Sendzimir mill neural network multi-layer perceptron echo state network shape recognition

Omni-functional simultaneous interfacial treatment for enhancing stability and outgassing suppression of lithium-ion batteries

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Journal of Energy Chemistry 2024年第7期94卷 677-687页

作者： Youbean Lee Chanjoo park Kyoungmin min Kwangjin park Department of Mechanical Engineering Gachon UniversityGyeonggi-do 13120Republic of Korea Department of Battery Engineering Gachon UniversityGyeonggi-do 13120Republic of Korea School of Mechanical Engineering Soongsil UniversitySeoul 06978Republic of Korea

Ni-rich layered oxides in lithium-ion batteries have problems with gas generation and electrochemical performance reduction due to residual lithium's reaction on the surface with the *** address this issue,in this study,the Acid solvent evaporation(AsE)method has been proposed as a potential method to remove residual lithium while promoting the formation of a new LiNO_(3)-derived coating layer on the cathode *** reduction of residual lithium using the ASE method and the construction of a LiNO_(3)-derived coating layer suppresses gas evolution caused by the side effects of the electrolyte,improves electrochemical performance,and improves thermal stability by facilitating the smooth movement of lithium ***,the structural stability and resistance change due to the LiNO_(3)-derived coating layer effects is guaranteed through cycling and DCIR of the pouch *** a result,compared to Pristine,the capacity retention of coin cells increased by 8%after 100 cycles,and pouch cells increased by 25%after 160 *** addition,after cycling the pouch cell,CO_(2) gas has significantly reduced by about 30%compared to Pristine using gas *** ASE method effectively forms a robust LiNO_(3)-derived coating layer on the cathode active material,which helps minimize electrolyte reactivity,suppress ,CO_(2) emissions,enhance surface structure stability,improve thermal stability,and improveoverallbatteryperformance.

关键词： Lithium-ion batteries Ni-rich NCM Acid solvent evaporation LiNO_(3)-derived coating Gasevolution

Effect of internal sloshing on added resistance of ship

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Journal of Hydrodynamics 2017年第1期29卷 13-26页

作者： min-Guk Seo Yonghwan Kim Dong-min park Korea Research Institute of Ships and Ocean Engineering DaejeonKorea Department of Naval Architecture and Ocean Engineering Seoul National UniversitySeoulKorea

The motion responses of ships carrying liquid cargo are affected not only by external wave excitation, but also by internal sloshing-induced forces and moments. Sloshing flow is coupled with the ship motion. This means the added resistance in waves may change when sloshing occurs inside the tank of the ship. In this study, the motion responses and added resistance of a ship, coupled with the sloshing-induced internal forces and moments are considered by using the linear potential theory. The three-dimensional Rankine panel method, in which the physical quantities are represented by using B-spline basis function, is applied. The sloshing flow of inner tanks is also simulated by Using the Rankine panel method and linearized boundary value problem. To study the added resistance, a near-field method, which integrates the second-order pressure on a body surface, is applied. The model ship is a blunt modified Wigley model with two inner tanks. Numerical results obtained without inner tanks are compared with the experimental data, and then the effect of filling ratio of inner tanks on ship motion and added resistance are observed. The components that induce added resistance are examined, and the effects of surge motion on sloshing flow and added resistance are briefly considered. This study shows that the sloshing flow inside the inner tanks may significantly influence not only the motion responses, but also added resistance, especially, when the incident wave frequency approaches the resonance frequency of the sloshing flow.

关键词： Added resistance sloshing seakeeping coupled effect Rankine panel method