Construction of High Strain Rate Loading Constitutive Model and Failure Model and Prediction of Forming Limit for LA103Z Magnesium Alloy

Hailiang Yang,Xiao Wang,Peng Ni,Zhewen Li,Huixia Liu 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

In order to use numerical simulation to reveal the formability of magnesium–lithium alloys and other light alloys under highstrain rate, it is crucial to construct a constitutive model and a forming limit diagram (FLD) of LA103Z alloy that was formedby laser shock at high strain rate. In this study, three different uniaxial tensile experiments on the ultralight alloy materialLA103Z magnesium alloy were conducted, the mechanical behavior of the material with sensitivity to high strain rate wasstudied, and a Johnson–Cook (JC) constitutive model sensitive to high strain rates and suitable for laser shock forming wasproposed. At the same time, the constitutive parameters and failure parameters of the modified JC model of LA103Z magnesiumalloy were obtained through three different uniaxial tensile experiments. On the basis of the relationship betweentensile loading and stress–strain of LA103Z magnesium alloy, the experiments demonstrated the precision of the modified JCconstitutive model. A modified constitutive model was then developed by using the user material subroutine VUMAT, andthen it was applied to ABAQUS. Finally, the formability of the material was simulated, and the FLD of LA103Z magnesiumalloy material in laser shock forming was predicted. This study provides guidance on the actual production and applicationof LA103Z magnesium alloys.

Bioactive Ingredients from Nitraria tangutorun Bobr. Protect Against Cerebral Ischemia/Reperfusion Injury Through Attenuation of Oxidative Stress and the Inflammatory Response

Hailiang Wang,Jianhong Zhou,Hongtao Bi,Xiaoyu Yang,Wenlong Chen,Kuijun Jiang,Yang Yao,Weihua Ni 한국식품영양과학회 2021 Journal of medicinal food Vol.24 No.7

Nitraria tangutorun Bobr. has been used for thousands of years as a native folk medicine to alleviate dizziness and neurasthenia due to oxygen. In our previous study, natural antioxidant components (namely, NJBE) were isolated from industrial N. tangutorun Bobr. juice byproducts (NJBE) from the Qinghai-Tibet plateau. The current investigation assessed the effects of NJBE on ischemic stroke in mice and the potential mechanisms. C57BL/6 mice received NJBE (25, 50, or 100 mg/Kg) by gavage for 14 days and then stroke was induced by the middle cerebral artery occlusion (MCAO) model, followed by reperfusion for 72 h. The evaluation of brain infarct size, behavioral tests, and functional assessments was conducted to assess the effects of NJBE after MCAO. Our results suggested that NJBE significantly decreases infarct size, improves neurological deficits, as well as reduces the number of GFAP+ and Iba-1+ cells after MCAO. NJBE inhibited nitric oxide and malondialdehyde production in the ischemic brain. Meanwhile, it attenuated the expressions of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Also, NJBE significantly attenuated the expression levels of proinflammatory indicators, including TNF-α, IL-1β, IL-6, and IL-12. This process was accompanied by the downregulation of TLR4, TRAF6, pIκB/pIκB, and MMP9 expression and the upregulation of claudin-5 expression. NJBE induced improvements in brain injury. The neuroprotective effect of NJBE provides evidence for its potential application in stroke treatment.

Reactive Current Assignment and Control for DFIG Based Wind Turbines during Grid Voltage Sag and Swell Conditions

Hailiang Xu,Xiaojun Ma,Dan Sun 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

This paper proposes a reactive current assignment and control strategy for a doubly-fed induction generator (DFIG) based wind-turbine generation system under generic grid voltage sag or swell conditions. The system’s active and reactive power constrains during grid faults are investigated with both the grid- and rotor-side convertors (GSC and RSC) maximum ampere limits considered. To meet the latest grid codes, especially the low- and high-voltage ride-through (LVRT and HVRT) requirements, an adaptive reactive current control scheme is investigated. In addition, a torque-oscillation suppression technique is designed to reduce the mechanism stress on turbine systems caused by intensive voltage variations. Simulation and experiment studies demonstrate the feasibility and effectiveness of the proposed control scheme to enhance the fault ride-through (FRT) capability of DFIG-based wind turbines during violent changes in grid voltage.

Reactive Current Assignment and Control for DFIG Based Wind Turbines during Grid Voltage Sag and Swell Conditions

Xu, Hailiang,Ma, Xiaojun,Sun, Dan The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.1

This paper proposes a reactive current assignment and control strategy for a doubly-fed induction generator (DFIG) based wind-turbine generation system under generic grid voltage sag or swell conditions. The system's active and reactive power constrains during grid faults are investigated with both the grid- and rotor-side convertors (GSC and RSC) maximum ampere limits considered. To meet the latest grid codes, especially the low- and high-voltage ride-through (LVRT and HVRT) requirements, an adaptive reactive current control scheme is investigated. In addition, a torque-oscillation suppression technique is designed to reduce the mechanism stress on turbine systems caused by intensive voltage variations. Simulation and experiment studies demonstrate the feasibility and effectiveness of the proposed control scheme to enhance the fault ride-through (FRT) capability of DFIG-based wind turbines during violent changes in grid voltage.

The research of translation issues in international military contests—— take the “International Military Contest-2018” as the example

XU Hailiang,ZHU Jian,LU Tian 한국외국어대학교 통번역연구소 2019 한국외국어대학교 통번역연구소 학술대회 Vol.2019 No.07

In the recent years, under the condition that the Chinese Army’s opening-up fields are getting enlarged and that its forms are getting diversified and intensity getting improved, Chinese soldiers are performing more actively in the international stages. Developing the international military cooperation holds great significance for the improvement of strategic mutual understanding, and the maintenance of worldwide and regional peace and stability. In August 2018, the sea-landing competition of “International Military Contest-2018” was held in Fujian, China. As the representative of Chinese Navy, I joined in the whole translation work of the competition, accumulating precious experience of military translation. By summarizing the translation experience of the contest, the paper aims at combing through possible problems when carrying out this kind of military contest task henceforward, and at studying relevant solutions and translation strategies.

Triptolide improves myocardial fibrosis in rats through inhibition of nuclear factor kappa B and NLR family pyrin domain containing 3 inflammasome pathway

Jianyao Shen,Hailiang Ma,Chaoquan Wang 대한생리학회-대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.6

Myocardial fibrosis (MF) is the result of persistent and repeated aggravation of myocardial ischemia and hypoxia, leading to the gradual development of heart failure of chronic ischemic heart disease. Triptolide (TPL) is identified to be involved in the treatment for MF. This study aims to explore the mechanism of TPL in the treatment of MF. The MF rat model was established, subcutaneously injected with isoproterenol and treated by subcutaneous injection of TPL. The cardiac function of each group was evaluated, including LVEF, LVFS, LVES, and LVED. The expressions of ANP, BNP, inflammatory related factors (IL-1β, IL-18, TNF-α, MCP-1, VCAM- 1), NLRP3 inflammasome factors (NLRP3, ASC) and fibrosis related factors (TGF-β1, COL1, and COL3) in rats were dete cted. H&E staining and Masson staining were used to observe myocardial cell inflammation and fibrosis of rats. Western blot was used to detect the p-P65 and t-P65 levels in nucleoprotein of rat myocardial tissues. LVED and LVES of MF group were significantly upregulated, LVEF and LVFS were significantly downregulated, while TPL treatment reversed these trends; TPL treatment downregulated the tissue injury and improved the pathological damage of MF rats. TPL treatment downregulated the levels of inflammatory factors and fibrosis factors, and inhibited the activation of NLRP3 inflammasome. Activation of NLRP3 inflammasome or NF-κB pathway reversed the effect of TPL on MF. Collectively, TPL inhibited the activation of NLRP3 inflammasome by inhibiting NF-κB pathway, and improved MF in MF rats.

Decentralized Adaptive Event-triggered Control for Nonlinear Interconnected Systems in Strict-feedback Form

Yuehui Ji,Hailiang Zhou,Qun Zong 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.4

The decentralized event triggered control problem is investigated for nonlinear interconnected systems in strict-feedback form subjected to parametric uncertainty. For each subsystem in the interconnected systems, the decentralized adaptive backstepping controller is designed to guarantee that the tracking error is semi-globally ultimately bounded. The control update and parameter estimate action are aperiodical executed only when the desired control specifications cannot be ensured, drastically reducing the computational burden and the transmission cost. It can be proved that zeno phenomenon is avoided as a positive lower bound on the minimal inter-sample time exists. The impulsive dynamical systems tools and Lyapunov analysis are introduced to prove the stability property for closed-loop system. Finally, a numerical simulation example is included to validate the effectiveness of the control scheme.

Force transmission performance for a novel deformation wheel with crank slider mechanism

Kongshu Deng,Hailiang Wu,Yicheng Ding,Lu Zeng,Zhurong Yin,Dilei Qian 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.6

This study aims to analyze the force transmission characteristics of a novel wheel composed of a mechanism of planar crank slider with virtual constraints. The principle of kinematic inversion is applied to analyze the force transmission characteristics of deformable wheel in an innovative way. First, the structural design of deformable wheel and diagram of mechanism motion are presented. Second, the model of force transmission characteristic of deformable wheel is established on the basis of principle of kinematic inversion. Third, the force changes in the two pairs of springs in the deformable wheel are investigated using MATLAB and ADAMS. Finally, the force transmission performance between the deformable and elastic wheel is compared. Results show that the possibility of a flat wheel can be avoided under severe geological conditions, and the force transmission performance is better than that of the traditional elastic wheel. The results of this study can provide theoretical guidance in designing a novel nonpneumatic wheel.

An experimental study on the ballistic performance of FRP-steel plates completely penetrated by a hemispherical-nosed projectile

Changhai Chen,Xi Zhu,Hailiang Hou,Lijun Zhang,Xiaole Shen,Ting Tang 국제구조공학회 2014 Steel and Composite Structures, An International J Vol.16 No.3

Experiments were carried out to investigate the ballistic performance of fiber reinforced plastic(FRP)-steel plates completely penetrated by hemispherical-nosed projectiles at sub-ordnance velocities greater than their ballistic limits. The FRP-steel plate consists of a front FRP laminate and a steel backing plate. Failure mechanisms and impact energy absorptions of FRP-steel plates were analyzed and compared with FRP laminates and single steel plates. The effects of relative thickness, manufacturing method and fabric type of front composite armors as well as the joining style between front composite armors and steel backing plates on the total perforation resistance of FRP-steel plates were explored. It is found that in the case of FRP-steel plates completely penetrated by hemispherical-nosed projectiles at low velocities, the failure modes of front composite armors are slightly changed while for steel backing plates, the dominate failure modes are greatly changed due to the influence of front composite armors. The relative thickness and fabric type of front composite armors as well as the joining style of FRP-steel plates have large effects whereas the manufacturing method of front composite armors has slight effect on the total perforation resistance of FRP-steel plates.

Finite groups all of whose maximal subgroups are SB-groups

Pengfei Guo,Junxin Wang,Hailiang Zhang 대한수학회 2014 대한수학회보 Vol.51 No.4

A finite group G is called a SB-group if every subgroup of G is either s-quasinormal or abnormal in G. In this paper, we give a complete classification of those groups which are not SB-groups but all of whose proper subgroups are SB-groups.