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Welding Performance of Low-Yield-Strength Steel Shear Panel Dampers Under Large Plastic Deformation
Chaofeng Zhang,Shixi Chen,Junhua Zhao,Xuchuan Lin,Lingxin Zhang,Jiajia Zhu,Weili Wang 한국강구조학회 2021 International Journal of Steel Structures Vol.21 No.6
Characterized by large plastic deformation and energy-dissipation capacity, low-yield-strength steel shear panel dampers (LYSPDs) are widely used as energy-dissipating members in seismic engineering. However, the eff ect of welding on the properties of LYSPDs remains unclear. Hence, in this study, we investigated the matching performance between low-yieldstrength steel (LYS) and two diff erent welding materials. Subsequently, the quality of welding between LYS and dissimilar metals was investigated. Furthermore, the fracture characteristics of the welding seam of LYS under large plastic deformation were explored. Finally, the welding performance of LYSPDs under large plastic deformation was verifi ed under cyclic loading. The results of this study are signifi cant in terms of the eff ect of welding on the properties of LYSPDs.
Structure of a permanent magnet motor used for electric vehicles to suppress the eddy current effect
Meiwei Zhang,Weili Li,Wanlu Xie,Liangliang Zhang 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.9
A demagnetization fault in the permanent magnet (PM) may occur when the temperature exceeds the limit temperature of the PM material due to the limited heat dissipation of the rotor in PM motors in the driving system of electric vehicles. In addition, PM thermal stress arises as a result of the unbalanced axial temperature distribution of the motor. When the thermal stress exceeds the yield strength of PM, micro-deformation of the PM structure happens and affects the performance and structural reliability of the motor. In this study, the rotor structure of an 18 kW PM motor is improved, and an eddy current ring structure of stainless steel is proposed. First, the effects of eddy current rings with axial lengths of 2, 5, and 10 mm on the eddy current losses of PM are compared. Second, a three-dimensional, steady-state temperature model of the motor is established to analyze the effects of the eddy current rings with different axial lengths on rotor temperature when the motor is running at different speeds. Results show that the eddy current ring structure with 2 mm axial length has the best effect on reducing rotor temperature. Lastly, the simulation results are verified using the test results of the 18 kW PM motor.
Research on Braking Process of High-speed Train with Aerodynamic Brake
Yonghua Zhu,Weilie Shang,Xia Zhang,Hongjie Yan,Pin Wu 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.12
The speed is higher, the kinetic energy is greater. In order to ensure the safety of a new generation train running in a high speed, it is necessary to research on its braking performance. In this paper, the braking force, running resistance, braking time, braking distance and the deceleration generated by the train with two kinds of braking wings were analyzed while the high-speed train was doing deceleration movement. And the results were compared and analyzed between the train with and without braking wing, and between the two kinds of braking wings. The results showed that the high speed train with braking wings made much contribution to the acceleration in the braking process, especially the train is in high speed.
Effect of myoglobin, hemin, and ferric iron on quality of chicken breast meat
Zhang, Muhan,Yan, Weili,Wang, Daoying,Xu, Weimin Asian Australasian Association of Animal Productio 2021 Animal Bioscience Vol.34 No.8
Objective: The objective was to evaluate the impact of different forms of iron including myoglobin, hemin, and ferric chloride on the quality of chicken breast meat. Methods: Chicken breast muscles were subjected to 1, 2, 3 mg/mL of FeCl<sub>3</sub>, myoglobin and hemin treatment respectively, and the production of reactive oxygen species (ROS) and malondialdehyde, meat color, tenderness, water holding capacity and morphology of meat was evaluated. Results: Hemin was found to produce more ROS and induce greater extent of lipid oxidation than myoglobin and ferric chloride. However, it showed that hemin could significantly increase the redness and decrease the lightness of the muscle. Hemin was also shown to be prominent in improving water holding capacity of meat, maintaining a relatively higher level of the immobilized water from low-field nuclear magnetic resonance measurements. Morphology observation by hematoxylin-eosin staining further confirmed the results that hemin preserved the integrity of the muscle. Conclusion: The results indicated that hemin may have economic benefit for the industry based on its advantage in improving water holding capacity and quality of meat.
Antimonene prepared by laser irradiation applied for nonlinear optical limiting
Weili Shen,Jinning Hu,Teng Ma,Jiaxin Wang,Yi Wei,Yuanzhou Zhang,Jinqiang Wu,Jun Chen 대한금속·재료학회 2021 ELECTRONIC MATERIALS LETTERS Vol.17 No.6
Antimonene, a novel two-dimension (2D) Group-VA material, shows excellent electrical and optical properties. In this work,antimonene nanosheets or nanoparticles were obtained by laser irradiating antimony powder in isopropanol solution anddiff erent morphology of antimonene were obtained by adjusting diff erent laser irradiation parameters, including irradiationtime and irradiation energy. The nonlinear absorption properties of antimonene with diff erent morphologies under 532 nmnanosecond laser were studied by Z-scan technology. It was found that the reverse-saturation absorption ability was thestrongest when the morphology of the sample was nanosheets, which was very suitable for optical limiting. In addition, dueto the limitation of the application of the sample in the form of solution, we added it into organosilicon, and obtained thesolid antimonene-organosilicon composite with optical limiting function. The results showed that antimonene nanosheetswith best optical limiting ability can be prepared by adjusting the laser irradiation parameters, and the products are successfullyadded into solid matrix to enhance its practicability in protecting people’s eyes and optical equipment from damagecaused by high power laser.
Structured Learning for 3-D Perivascular Space Segmentation Using Vascular Features
Zhang, Jun,Gao, Yaozong,Park, Sang Hyun,Zong, Xiaopeng,Lin, Weili,Shen, Dinggang IEEE 2017 IEEE Transactions on Biomedical Engineering Vol.64 No.12
<P>Objective: The goal of this paper is to automatically segment perivascular spaces (PVSs) in brain from high-resolution 7T magnetic resonance (MR) images. Methods: We propose a structured-learning-based segmentation framework to extract the PVSs from high-resolution 7T MR images. Specifically, we integrate three types of vascular filter responses into a structured random forest for classifying voxels into two categories, i.e., PVS and background. In addition, we propose a novel entropy-based sampling strategy to extract informative samples in the background for training an explicit classification model. Since the vascular filters can extract various vascular features, even thin and low-contrast structures can be effectively extracted from noisy backgrounds. Moreover, continuous and smooth segmentation results can be obtained by utilizing patch-based structured labels. Results: The performance of our proposed method is evaluated on 19 subjects with 7T MR images, with the Dice similarity coefficient reaching 66%. Conclusion: The joint use of entropy-based sampling strategy, vascular features, and structured learning can improve the segmentation accuracy. Significance: Instead of manual annotation, our method provides an automatic way for PVS segmentation. Moreover, our method can be potentially used for other vascular structure segmentation because of its data-driven property.</P>
Weili Cheng,Yanhui Liu,Yao Zhang,Shuaiju Meng,Srinivasan Arthanari,Hong‑xia Wang,Lifei Wang 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.11
A novel dilute Mg–0.5Sn–0.7Al–0.8Zn alloy was developed and directly extruded after casting process. The extrudedalloy consisted of fine bimodal grained microstructure, local nano-precipitates micro-region and typical extrusion direction(ED)-tilted texture. A great balance between tensile properties (YS = 262.7 MPa, EL = 26.0%) and corrosion resistance(Pi = 1.57 mm/a) was achieved and discussed in terms of grain size, structure, orientation as well as precipitates and/or corrosionproduct film. As a result, this dilute alloy system shows the great potential to be developed as a biomaterial.
Meiwei Zhang,Weili Li,Wanlu Xie,Haoyue Tang,Zhigang Wu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.3
The power density of a high-speed permanent magnet (PM) motor is high, and the heat dissipation of its rotor is poor due to limited installation space. Th0000000000000000000us, the temperature of the permanent magnets is high. Once the cooling system of a motor becomes ineffective and the rotor temperature exceeds the limit temperature of the PM material, a demagnetization fault of the PM occur, which seriously affects the performance of the PM motor. To ensure the safe and reliable operation of PM motors, a method to diagnose the PM health is presented in this paper. The demagnetization ratio of the PM can be diagnosed quantitatively by its temperature. In this paper, the relationship between the temperature and the demagnetization ratio of a PM is obtained through thermal demagnetization tests, and the threshold temperature of demagnetization is given. Then, the health of a PM under different effectiveness of the cooling system in a high-speed PM motor is researched. Finally, the calculation results are verified by temperature tests of a high-speed PM motor.