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Wenchao Yang,Pengfei Qu,Ruirong Zhang,Jiarun Qin,Chen Liu,Jun Zhang,Lin Liu 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6
Three-dimensional atom-probe tomography was used to characterize the γ/γʹ interface structure in a third-generation Nibasedsingle crystal superalloy with Re addition. It was found that an element-segregation layer with Re, Co and Cr wasformed in the γ phase close to the γ/γ′ interface, resulting in a more negative local interface misfit (− 0.29%) compared tothe measured result (− 0.16%) from high-resolution X-ray diffraction. Furthermore, the total reduction of interfacial freeenergy due to the solute atom segregation based on the Gibbsian interfacial excess was calculated to indicate that Re elementwas the most beneficial element in producing this more negative local misfit with the largest interfacial free energy reduction(13.67 ± 0.21 mJ/m2). Simultaneously, because of the co-segregation of Re, Co and Cr, and the depletion of Ni in the γphase close to the γ/γ′ interface, it was also deduced that some harmful topologically close-packed phases might be easierto nucleate and grow in the γ phase close to the γ/γ′ interface in service.
Melt Superheating on the Microstructure and Mechanical Properties of Diecast Al-Mg-Si-Mn Alloy
Wenchao Yang,Xinliang Yang,Shouxun Ji 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.2
The application of aluminium alloys in automotive body structure is one of the main developments in recentyears. The increase of the mechanical properties of the ductile die-casting is one of the most critical topics forthe application. In this work, the effect of melt superheating on the morphology, size and distribution of α-Alphase and Fe-rich intermetallics, and on the mechanical properties of the Al-Mg-Si-Mn diecast alloy wasinvestigated. The results showed that the refined microstructure could be obtained through melt superheating. The volume fraction of dendritic α-Al phase and the Fe-rich intermetallic phase formed in the shotsleeve was significantly reduced, resulting in the refined microstructure. Overall, the melt superheatingcould improve the mechanical properties of the yield strength, ultimate tensile strength, and elongation ofthe diecast Al-Mg-Si-Mn alloy. And, the Fe-rich intermetallic phase formed in the shot sleeve with thecoarse compact morphology and formed in the die cavity with the fine compact particles were identifiedas the same α-Al12(Fe,Mn)3Si composition in the present experimental conditions, which was not affectedby the melt superheating.
Qin Wenchao,Feng Liwei,Yang Zihao,Liu Jinfeng,Liu Yan 한국물리학회 2021 Current Applied Physics Vol.32 No.-
LiNi0.5Co0.2Mn0.3O2 (NCM523) was coated by a lithium-ion conductor Li3PO4 layer using a pre-coating treatment and solid state method. The physicochemical characteristics were investigated by XRD, SEM, TEM and XPS. Li3PO4 coating layer maintained the crystal structure of NCM523 cathode. The cathode with 3.0 wt% Li3PO4 coating (P0.03-NCM) exhibited outstanding rate capability (169.3 mAh g 1 at 0.2 C) and cycling retention of 92.23% at 1 C after 150 cycles, whereas the pristine NCM exhibited a capacity retention of only 77.84%. The electrochemical performance of the full-cell (P0.03-NCM as the cathodes and graphite as the anodes) showed high cycle retention of 82.92% after 100 cycles. The Li3PO4 coating layer acted as a physical barrier and alleviated the degradation behaviors of NCM523. This research work provided insights for the commercial application of ternary layered cathodes.
A Divided Two-Lane Cellular Automaton Model of Traffic Flow Considering Driving Tendency
Longhai Yang,Xiqiao Zhang,Wenchao Ji 대한토목학회 2018 KSCE JOURNAL OF CIVIL ENGINEERING Vol.22 No.12
Different types of drivers usually take on different driving tendency on urban road, based on the diversity of driving tendency, a new two-lane cellular automaton model was proposed under condition of periodical boundary. The mean speed, flow volume and lane-changing frequency under different lane-changing and deceleration rules were simulated. In the process of computational simulation, the fundamental diagrams of traffic flow under different rules were obtained by changing traffic flow density. Simulation results show that the proposed new rules can improve traffic flow volume and suppress traffic jam to a certain degree. Finally, the critical points were discussed to show the impact of lane-changing on traffic flow.
Canli Hu,Wenchao Zhao,Jingwei Fan,Zilong Li,Rui Yang,Fukuan Zhao,JianLi Wang,Shaohui Wang 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.4
Root-knot nematodes (RKNs; Meloidogyne spp.) are obligate endoparasites that infect a large number of crop plants and cause severe yield losses. Tomato cultivars carrying the Mi-1 gene conferring root-knot nematode resistance have been widely used, but this gene loses its effectiveness at soil temperatures above 28°C. In this study, the mechanism of the loss of resistance to RKNs at high soil temperatures was examined using LA0655 (Solanum lycopersicum cv. Anahu), which contains the Mi-1 gene. It was found that high soil temperatures delayed the expression of the Mi-1 gene and reduced the activities of superoxide dismutase, peroxidase, chitinase, and β-1,3-glucanase. Although genes in the jasmonic acid (JA) pathway exhibited an obvious response at high soil temperatures, this response could not prevent the invasion of RKNs; indeed, at 30 days after inoculation with RKNs, the plants produced large numbers of root knots and egg masses at a soil temperature of 32°C.
Haiyuan Liu,Yang Shi,Yinan Guo,Yingjie Wang,Wenchao Wang 전력전자학회 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4
In medium-voltage and high-voltage high-power converters, the switching devices need to operate at a low switching frequency toreduce power loss and increase the power capacity. This increases the delay of the signal sampling and PWM. It also makes thecross-couplings of the d-q current components more severe. In addition, the LCL filter has three cross-coupling loops and is prone toresonance. In order to solve these problems, this paper establishes a complex vector model of an LCL type grid-connected converter. Based on this model, two multiple decoupling current control strategies with passive damping / notch damping are proposed for theLCL type grid-connected converter. The proposed strategies can effectively eliminate the cross-couplings of the converter, achieveindependent control of the d-q current components, expand the stable region and suppress the resonance of the LCL filter. Simulation and experimental results verify the correctness of the theoretical analysis and the feasibility of the proposed strategies.
Xiaoman Li,Wenchao Zhao,Xiaoxuan Zhou,Jiaping Feng,Yingjian Gao,Xuehui Yao,Yang Liu,Jie Liu,Rui Yang,Fukuan Zhao,Shaohui Wang 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.6
Root-knot nematodes (RKNs) (Meloidogyne spp.) are one of the most damaging crop pests and cause severeyield losses worldwide. Easier and more efficient methods are needed for assessing nematode infestations and hostplant resistance. In the present study, we combined toluidine blue staining and paraffin sectioning to observe theestablishment of giant cells (GCs; redifferentiated cells induced by nematode feeding) and the developmental status ofRKNs in tomato (Solanum lycopersicum). The number of RKNs was counted using a modified freeze-thaw countingmethod. Finally, three tomato lines with different levels of RKN resistance, but otherwise identical genetic backgrounds,were tested to verify the applicability of the combined method. The results suggested that using toluidine blue stainingcombined with paraffin sectioning and freeze-thaw counting accurately reflects the level of RKN resistance of tomato plants.
The processes on graft union formation in tomato
Jingwei Fan,Rui Yang,Xiaoman Li,Wenchao Zhao,Fukuan Zhao,Shaohui Wang 한국원예학회 2015 Horticulture, Environment, and Biotechnology Vol.56 No.5
Despite the long and widespread use of grafting in tomato cultivation, the structural changes that occur at the graft union during the early stages of the union remain poorly understood. In this study, the structural development of the graft union in tomato plants was examined 3, 5, 8, 11 and 14 days after grafting (DAG) using scanning electron microscopy (SEM) and a paraffin sectioning technique. The paraffin-sectioned images of the transection revealed that parenchymal cells from the graft union divided and proliferated in most combinations, and these cells could be detected at various stages of development. The SEM images of the scion and rootstock longitudinal sections showed that many interconnecting structures appeared at 8 DAG and were followed by a vascular rearrangement that did not connect the scion and rootstock. Vascular bundle bridges appeared at 11 DAG and connected the scion and rootstock. The connection of graft union between rootstock and scion is influenced by the plant growth condition. In our managed environment, period for formation of the connection structure formation between the rootstock and scion was 7-14 days after grafting.
An analysis of physiological index of differences in drought tolerance of tomato rootstock seedlings
Xuehui Yao,Rui Yang,Fukuan Zhao,Shaohui Wang,Changbao Li,Wenchao Zhao 한국식물학회 2016 Journal of Plant Biology Vol.59 No.4
Drought is one of the most limiting factors for plant growth and development. In this study, experiments were carried out on five tomato rootstocks were subjected to water withdrawal and re-watering. Two RKN (root-knot nematodes)-and drought-dual resistant rootstocks were identified according to phenotype, physiological and molecular indexes such as the leaf relative water content (LRWC), electrolyte leakage (EL), water loss of the leaf, proline content, and increased activities of antioxidant enzymes, including peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR) and the transcript levels of drought stress marker genes. Further, we preliminarily investigated the mechanism underlying improved drought tolerance arising from grafting. These results will promote the application of these rootstocks in tomato production and provide new information on the mechanism of tomato grafting.
Liu, Haiyuan,Shi, Yang,Guo, Yinan,Wang, Yingjie,Wang, Wenchao The Korean Institute of Power Electronics 2019 JOURNAL OF POWER ELECTRONICS Vol.19 No.4
In medium-voltage and high-voltage high-power converters, the switching devices need to operate at a low switching frequency to reduce power loss and increase the power capacity. This increases the delay of the signal sampling and PWM. It also makes the cross-couplings of the d-q current components more severe. In addition, the LCL filter has three cross-coupling loops and is prone to resonance. In order to solve these problems, this paper establishes a complex vector model of an LCL type grid-connected converter. Based on this model, two multiple decoupling current control strategies with passive damping / notch damping are proposed for the LCL type grid-connected converter. The proposed strategies can effectively eliminate the cross-couplings of the converter, achieve independent control of the d-q current components, expand the stable region and suppress the resonance of the LCL filter. Simulation and experimental results verify the correctness of the theoretical analysis and the feasibility of the proposed strategies.