Characteristics and Optimization of New Combined Magnetic Pole Negative-Salient Permanent Magnet Motor

Wang Wenqiang,Shi Liwei,Qiao Zhiwei,Zhu Yingjie,Ding Hongshan 대한전기학회 2024 Journal of Electrical Engineering & Technology Vol.19 No.3

With a wide speed range, high overload capacity and preventing permanent magnet demagnetization, negative-salient permanent magnet motors have a wide range of applications in the feld of electric vehicles. In view of the multiple operating conditions of the electric vehicle drive motor, this paper proposes a new type of combined magnetic pole negative-salient permanent magnet motor considering the driving conditions. Firstly, the optimization parameters of the motors are determined according to the analysis of the mathematical model. The design parameters are layered by the comprehensive sensitivity analysis, and the response surface Box-Behnken Design method and multi-objective genetic algorithm-II are used for optimization. Then, the electromagnetic performance of the proposed motor and the traditional interior permanent magnet motors are compared and analyzed through the fnite element simulation. Finally, a prototype is manufactured and the rationality of the proposed motor structure is verifed by experiments.

Experimental Study on the Damage of Steel Tubular Structural Components by Near-Field Detonations

Wanyue Wang,Shaobo Geng,Hua Wang,Wenqiang Li,Yaling Liu,Jianying Xue,Tingbian Zhan,Ying Gao 대한토목학회 2021 KSCE Journal of Civil Engineering Vol.25 No.2

This paper describes three blast-loading trials on three kinds of steel tubular structural components at the same explosive charge and standoff distance. Specimen one is a hollowsteel tube (HST), another is a HST wrapped with glass fibre-reinforced plastic (GFRP) with epoxy resin and the third is a HST infilled with concrete. The main objective of the trials is to investigate the effect of near-field detonations on circular steel tubular components. The experimental data, such as the overpressure time history, front local deformation, rear residual deflection and strain time history, are all recorded and collected. Analysis of the trial results shows that the experimental peak overpressure values of shot 1-3 are all larger than that of numerical simulation. The failure of these three specimens mainly experiences local damage, at the same time, the HST and HST with GFRP exhibit obvious global deformation. With the initiation point at one end of the cylinder explosive, both the maximum depth deformation on the front surface and the maximum residual deflection on the rear surface are all located on the side of the another end of the cylinder explosive. The blast-resistant approach by covering 10-layer GFRP on the surface of the HST can reduce the local damage, the global deformationand the dynamic strain value to certain extent, while the approach by infilling the steel tube with concrete can greatly decrease the local damage and the dynamic strain value and without any global deformation.

A national survey on how to improve traditional Chinese medicine learning internationally: Perceptions from both teachers and students

Zhu Yu-Hang,Yan Wu,Hao Zhang,Yanfei Zhao,Yule Ren,Wei Hu,Pan Li,Huiyi Wang,Ying Wang,Boda Zhang,Yujie Wang,Hongwen Yuan,Jiping Zhang,Wenqiang Li,Yufang Zhao,Jie Zhao,Yedong Shi,Yanye Shu,Xiao Zhang,Ya 한국한의학연구원 2022 Integrative Medicine Research Vol.11 No.4

Background With the increasing popularity of traditional Chinese medicine (TCM) by the global community, how to teach basic knowledge of TCM to international students and improve the teaching quality are important issues for teachers of TCM. The present study was to analyze the perceptions from both students and teachers on how to improve TCM learning internationally. Methods A cross-sectional national survey was conducted at 23 universities/colleges across China. A structured, self-reported on-line questionnaire was administered to 34 Chinese teachers who taught TCM course in English and to 1016 international undergraduates who were enrolled in the TCM course in China between 2017 and 2021. Results Thirty-three (97.1%) teachers and 900 (88.6%) undergraduates agreed Chinese culture should be fully integrated into TCM courses. All teachers and 944 (92.9%) undergraduates thought that TCM had important significance in the clinical practice. All teachers and 995 (97.9%) undergraduates agreed that modern research of TCM is valuable. Thirty-three (97.1%) teachers and 959 (94.4%) undergraduates thought comparing traditional medicine in different countries with TCM can help the students better understand TCM. Thirty-two (94.1%) teachers and 962 (94.7%) undergraduates agreed on the use of practical teaching method with case reports. From the perceptions of the undergraduates, the top three beneficial learning styles were practice (34.3%), teacher's lectures (32.5%), case studies (10.4%). The first choice of learning mode was attending to face-to-face teaching (82.3%). The top three interesting contents were acupuncture (75.5%), Chinese herbal medicine (63.8%), and massage (55.0%). Conclusion To improve TCM learning among international undergraduates majoring in conventional medicine, integration of Chinese culture into TCM course, comparison of traditional medicine in different countries with TCM, application of the teaching method with case reports, and emphasization of clinical practice as well as modern research on TCM should be fully considered.

Investigation on High Temperature Mechanical Behaviors of TiC-γ′ Reinforced Ni Composite

Wenqiang Hu,Zhenying Huang,Qun Yu,Yuanbo Wang,Yidan Jiao,Yang Zhou,Hongxiang Zhai 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.8

A duplex TiC and γ′-Ni3(Al,Ti) reinforced nickel composite was fabricated through hot-press sintering a 30 vol% Ti2AlC–Nimixtures followed by thermal treatment method. Detailed microstructural detection was performed by adopting the routeof high-resolution transmission electron microscopy. In situ generated submicron TiC particulate and nanosized L12-γ′were homogeneously distributed in a fcc γ-Ni matrix. The high temperature tensile and compression behaviors of the TiC-γ′/Ni composites were evaluated in the temperature range of 25–800 °C. The results indicated that ultimate tensile andcompression properties exhibited the dependence of temperatures. The tensile properties of the composite determined at600 °C was 945 MPa, decreasing by 28.1% and 23.0% for elongation, compared to those of measured at room temperature(UTS = 1305 MPa, elongation = 5.35%). However, the yield strength exhibited the temperature independent until to 600 °C. The yield strength of the TiC-γ′/Ni composite are comparable with conventional superalloy under 600 °C, proving that TiCand γ′ particles constitute efficient reinforcements for Ni matrix according to thermal expansion dislocations strengthening,load-transfer and coherent strengthening mechanisms. The monotonic temperature dependence of yield strength at600–800 °C indicates that plastic deformation of TiC-γ′/Ni composite follows the thermally activated mechanism. TheTiC-γ′/Ni composite exhibited superior mechanical properties both at room and high temperatures, which can be ascribedto the synergistic strengthening effect in term of dislocation density, Orowan, coherent and atomic ordering strengtheningmechanisms. The present work reveals the deformation behaviors of in situ TiC-γ′/Ni composite from room to high temperatures,which is critical to predict the failure and thereby optimize the microstructure to further enhance the high temperatureproperties of TiC-γ′/Ni composite.

Experimental Study of Shear Strength Features of Regenerated Rock Mass compacted and consolidated by Broken Soft Rocks

Wenqiang Ma,Tongxu Wang 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.4

Rock mass composed of Broken Soft Rocks (BSR) under confined compression is widely distributed in geotechnical and underground engineering. To reveal the influence law of rock grain gradation and compression ratio on the shear strength properties of Regenerated Rock Mass Structure (RRMS) formed by confined compression of BSR, first, a series of compression tests of BSR with different grain gradation and compression ratios were carried out with homemade compression cylinders, through which the compression behavior of BSR was gained. In addition, the achieved Cylindrical RRMS (CRRMS) after compression was used for shear tests. Second, shear strength parameters of the CRRMS were obtained through shear tests under changing shear angle. It turns out that the CRRMS of smaller grain gradation has a better compaction degree and smoother surface. Nevertheless, the CRRMS of larger grain gradation, in contrast, has obvious gaps and a rough surface. During the compression process, the BSR of smaller grain gradation requires larger axial compression force, and the BSR of mixed grain gradations, which contain smaller grain gradation, has a better compaction effect than others. The internal friction angle of CRRMS increases with the growth in rock grain gradation, and the incremental rate of mixed grain gradations is less than those of the others. The change trend of cohesion is contrary to the internal friction angle, which decreases with the increase in grain gradation. With the homogeneous increase in the compression ratio, the internal friction angle decreases gradually, while the cohesion is contrary to the internal friction angle.

Effect of the scanning speed of laser cladding on microstructure and mechanical properties of WC/Ni composite coatings

Wenqiang Sun,Deqiang Zhang,Xiang Chen,Keyan Wang,Jiqing Zhang,Yunjie Jia 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.2

Cold work dies (of Cr12MoV) surface of the WC/Ni composite coating prepared by laser cladding can be used to quickly repair worn areas of dies. The composition, hardness, fracture morphology, microstructure, and shear strength of the coating were characterized by microhardness tester, universal tensile testing machine, XRD, EDS, and SEM. The results show that the main phase of the coating is composed are M 23 C 6 , FeNi 3 , Cr 7 C 3 , WC, W 2 C, Cr 2 B, Fe 2 B, and W 2 B. The change of scanning speed only changes the diffraction peak, but has little effect on the internal structure and strengthening mechanism of the coating. With the decrease of scanning speed, the powder deposition density per unit time increases, and a large number of pores and unmelted particles are mixed in the coating, which weakens the bonding strength between the coating and the substrate, and the fracture mechanism of the coating changes from quasi-cleavage fracture to brittle fracture.

Analysis of synonymous codon usage bias in helicase gene from Autographa californica multiple nucleopolyhedrovirus

Hongju Wang,Tao Meng,Wenqiang Wei 한국유전학회 2018 Genes & Genomics Vol.40 No.7

The helicase gene of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is not only involved in viral DNA replication, but also plays a role in viral host range. To identify the codon usage bias of helicase of AcMNPV, the codon usage bias of helicase was especially studies in AcMNPV and 41 reference strains of baculoviruses by calculating the codon adaptation index (CAI), effective number of codon (ENc), relative synonymous codon usage (RSCU), and other indices. The helicase of baculovirus is less biased (mean ENc = 50.539 > 40; mean CAI = 0.246). AcMNPV helicase has a strong bias toward the synonymous codons with G and C at the third codon position (GC3s = 53.6%). The plot of GC3s against ENc values revealed that GC compositional constraints are the main factor that determines the codon usage bias of major of helicase. Several indicators supported that the codon usage pattern of helicase is mainly subject to mutation pressure. Analysis of variation in codon usage and amino acid composition indicated AcMNPV helicase shows the significant preference for one or more postulated codons for each amino acid. A cluster analysis based on RSCU values suggested that AcMNPV is evolutionarily closer to members of group I alphabaculovirus. Comparison of the codon usage pattern among E. coli, yeast, mouse, human and AcMNPV showed that yeast is a suitable expression system for AcMNPV helicase. AcMNPV helicase shows weak codon usage bias. This study may help in elucidating the functional mechanism of AcMNPV helicase and the evolution of baculovirus helicases.

Recent advances on surface modification of non‑oxide photocatalysts towards efficient CO2 conversion

Hanghang Zhou,Wenqiang Ye,Jizhou Jiang,Zheng Wang 한국탄소학회 2024 Carbon Letters Vol.34 No.6

Optimal Power Allocation for Wireless Uplink Transmissions Using Successive Interference Cancellation

( Liaoyuan Wu ),( Yamei Wang ),( Jianghong Han ),( Wenqiang Chen ),( Lusheng Wang ) 한국인터넷정보학회 2016 KSII Transactions on Internet and Information Syst Vol.10 No.5

Successive interference cancellation (SIC) is considered to be a promising technique to mitigate multi-user interference and achieve concurrent uplink transmissions, but the optimal power allocation (PA) issue for SIC users is not well addressed. In this article, we focus on the optimization of the PA ratio of users on an SIC channel and analytically obtain the optimal PA ratio with regard to the signal-to-interference-plus-noise ratio (SINR) threshold for successful demodulation and the sustainable demodulation error rate. Then, we design an efficient resource allocation (RA) scheme using the obtained optimal PA ratio. Finally, we compare the proposal with the near-optimum RA obtained by a simulated annealing search and the RA scheme with random PA. Simulation results show that our proposal achieves a performance close to the near-optimum and much higher performance than the random scheme in terms of total utility and Jain`s fairness index. To demonstrate the applicability of our proposal, we also simulate the proposal in various network paradigms, including wireless local area network, body area network, and vehicular ad hoc network.

Microstructural and Mechanical Properties of TiCX–Ni3(Al,Ti)/Ni Functionally Graded Composites Fabricated from Ti3AlC2 and Ni Powders

Guangming Zheng,Zhenying Huang,Qun Yu,Wenqiang Hu,Xingyang Qiu,A. Lixia,Yuanbo Wang,Yidan Jiao,Yang Zhou,Hongxiang Zhai 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.6

In this paper, a novel type of functionally graded material (FGM) was successfully fabricated from pure Ni and Ti3AlC2powder mixtures by hot-press sintering route at 1200 °C and 17 MPa. In each layer, Ti3AlC2particles transformed into TiCxphase, while the additional Al–Ti atoms decomposed from Ti3AlC2diffused into the Ni matrix, giving rise to the formationof γ′-Ni3(Al,Ti). Part of the submicron TiCxand Ni3(Al,Ti) particles were uniformly distributed in the Ni matrix, whilesome of the TiCxmaintained the original Ti3AlC2plate-like morphology. Both TiCxand Ni3(Al,Ti) content decreased from60Ti3AlC2/Ni layer to 10Ti3AlC2/Ni layer in a stepwise manner was fabricated. The microstructural analysis indicatesthat no cracks, delamination and step-type abrupt changes occured in the graded layer of the manufactured FGM. Flexuralstrength and Vickers hardness enhanced with the increasing Ti3AlC2content except for fracture strain and toughness. Theoverall fracture toughness and the flexural strength of FGM can reach 21.76 MPa m1/2 and 1329 ± 34 MPa, respectively. Theprepared FGM, herein, with a hard ceramic surface on one side to resist local plastic deformation, and a ductile metallicsurface on the other side to provide toughness.