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| 1 | Effects of grain boundary ternary alloy doping on corrosion resistance of(Ce,Pr,Nd)-Fe-B permanent magnets显示文摘To satisfy the application of different environments,grain boundary doping is commonly used in the preparation of sintered magnets to improve the coercivity and the corrosion resistance.In this paper,the alloys were prepared by mixing different ratios of the master alloy(Ce,Pr,Nd)-Fe-B and the sintering aid(Pr,Nd)-Al.The coercivity of sintered(Ce,Pr,Nd)-Fe-B magnet is substantially enhanced by doping 2 wt%of(Pr,Nd)-Al,while the maximum energy product decreases slightly.We systematically investigated the corrosion behavior and micro structure of the sintered magnets in order to determine the mechanism of the degradation.The sintered(Ce,Pr,Nd)-Fe-B magnets with 2 wt% of(Pr,Nd)-Al addition exhibit the decreasing corrosion rate compared with others,due to the distribution of intergranular phases.The electrode potential difference between the main phase and the RE-rich phase is reduced by the addition of Al,improving the potential and stability of RE-rich phase due to the higher electrode potential of Al than that of Nd,Pr or Ce.In addition,the element distribution of the magnets doped by(Pr,Nd)-Al indicates that the Al-rich shell formed at the marginal area of the Ce-rich phase improves its stability.Therefo re,intergranular adding te rnary(Pr,Nd)-Al alloy powders results in both high coe rcivity and good corrosion resistance synchronously. | Xin Wang Minggang Zhu Feng Xi Meiling Zhang Fei Liu Yingjian Guo Lele Zhang Guangrui Zhang Wei Li | 2021 | Journal of Rare Earths2021，39，8： | 6 |
| 2 | Online adaptive Q-learning method for fully cooperative linear quadratic dynamic games显示文摘A model-based offline policy iteration(PI) algorithm and a model-free online Q-learning algorithm are proposed for solving fully cooperative linear quadratic dynamic games. The PI-based adaptive Q-learning method can learn the feedback Nash equilibrium online using the state samples generated by behavior policies, without sending inquiries to the system model. Unlike the existing Q-learning methods, this novel Q-learning algorithm executes both policy evaluation and policy improvement in an adaptive manner.We prove the convergence of the offline PI algorithm by proving its equivalence to Newton’s method while solving the game algebraic Riccati equation(GARE). Furthermore, we prove that the proposed Q-learning method will converge to the Nash equilibrium under a small learning rate if the method satisfies certain persistence of excitation conditions, which can be easily met by suitable behavior policies. Our simulation results demonstrate the good performance of the proposed online adaptive Q-learning algorithm. | Xinxing LI Zhihong PENG Lei JIAO Lele XI Junqi CAI | 2019 | Science China(Information Sciences)2019，62，12： | 4 |
| 3 | Decentralized MPC-Based Trajectory Generation for Multiple Quadrotors in Cluttered Environments显示文摘Challenges in motion planning for multiple quadrotors in complex environments lie in overall°ight e±ciency and the avoidance of obstacles,deadlock,and collisions among themselves.In this paper,we present a gradient-free trajectory generation method for multiple quadrotors in dynamic obstacle-dense environments with the consideration of time consumption.A model predictive control(MPC)-based approach for each quadrotor is proposed to achieve distributed and asynchronous cooperative motion planning.First,the motion primitives of each quadrotor are formulated as the boundary state constrained primitives(BSCPs)which are constructed with jerk limited trajectory(JLT)generation method,a boundary value problem(BVP)solver,to obtain time-optimal trajectories.They are then approximated with a neural network(NN),pre-trained using this solver to reduce the computational burden.The NN is used for fast evaluation with the guidance of a navigation function during optimization to guarantee°ight safety without deadlock.Finally,the reference trajectories are generated using the same BVP solver.Our simulation and experimental results demonstrate the superior performance of the proposed method. | Xinyi Wang Lele Xi Yizhou Chen Shupeng Lai Feng Lin Ben M.Chen | 2021 | Guidance, Navigation and Control2021，1，2： | 1 |
| 4 | Early cardioprotection by insulin alleviates chronic adverse changes in post-ischemic cardiac structure and function显示文摘Insulin has been shown to possess significant anti-apoptotic effect in myocardial ischemia/reperfusion (MI/R). However, the contribution by this protection of insulin to | Wenjuan Xing1, Wenjun Yan1, Feng Fu1, Lele Ji1, Wenchong Liu1, Li Wang1, Anlin Lv1, Yunyan Duan2, Jun Zhang2, Haifeng Zhang1, Feng Gao1 1Department of Physiology and Department of Cardiology 2Department of Ultrasonic Diagnosis, Xijing Hospital, Fourth Military Medical University, Xi’an 710032 | 2009 | 生物物理学报2009，25，S1： | 1 |
| 5 | Trilogy of drug repurposing for developing cancer and chemotherapy-induced heart failure co-therapy agent显示文摘Chemotherapy-induced complications,particularly lethal cardiovascular diseases,pose significant challenges for cancer survivors.The intertwined adverse effects,brought by cancer and its complication,further complicate anticancer therapy and lead to diminished clinical outcomes.Simple supplementation of cardioprotective agents falls short in addressing these challenges.Developing bifunctional co-therapy agents provided another potential solution to consolidate the chemotherapy and reduce cardiac events simultaneously.Drug repurposing was naturally endowed with co-therapeutic potential of two indications,implying a unique chance in the development of bi-functional agents.Herein,we further proposed a novel“trilogy of drug repurposing”strategy that comprises function-based,targetfocused,and scaffold-driven repurposing approaches,aiming to systematically elucidate the advantages of repurposed drugs in rationally developing bi-functional agent.Through function-based repurposing,a cardioprotective agent,carvedilol(CAR),was identified as a potential neddylation inhibitor to suppress lung cancer growth.Employing target-focused SAR studies and scaffold-driven drug design,we synthesized 44 CAR derivatives to achieve a balance between anticancer and cardioprotection.Remarkably,optimal derivative 43 displayed promising bi-functional effects,especially in various self-established heart failure mice models with and without tumor-bearing.Collectively,the present study validated the practicability of the“trilogy of drug repurposing”strategy in the development of bi-functional cotherapy agents. | Xin Chen Xianggang Mu Lele Ding Xi Wang Fei Mao Jinlian Wei Qian Liu Yixiang Xu Shuaishuai Ni Lijun Jia Jian Li | 2024 | Acta Pharmaceutica Sinica B2024，14，2： | 0 |
| 6 | Cyasterone inhibits IL-1β-mediated apoptosis and inflammation via the NF-κB and MAPK signaling pathways in rat chondrocytes and ameliorates osteoarthritis in vivo显示文摘Osteoarthritis is a prevalent global joint disease,which is characterized by inflammatory reaction and cartilage degradation.Cyasterone,a sterone derived from the roots of Cyathula officinalis Kuan,exerts protective effect against several inflammationrelated diseases.However,its effect on osteoarthritis remains unclear.The current study was designed to investigate the potential antiosteoarthritis activity of cyasterone.Primary chondrocytes isolated from rats induced by interleukin(IL)-1βand a rat model stimulated by monosodium iodoacetate(MIA)were used for in vitro and in vivo experiments,respectively.The results of in vitro experiments showed that cyasterone apparently counteracted chondrocyte apoptosis,increased the expression of collagen II and aggrecan,and restrained the production of the inflammatory factors inducible nitric oxide synthase(iNOS),cyclooxygenase-2(COX-2),a disintegrin and metalloproteinase with thrombospondin motifs-5(ADAMTS-5),metalloproteinase-3(MMP-3),and metalloproteinase-13(MMP13)induced by IL-1βin chondrocytes.Furthermore,cyasterone ameliorated the inflammation and degenerative progression of osteoarthritis potentially by regulating the nuclear factor kappa B(NF-κB)and mitogen-activated protein kinase(MAPK)pathways.For in vivo experiments,cyasterone significantly alleviated the inflammatory response and cartilage destruction of rats induced by monosodium iodoacetate,where dexamethasone was used as the positive control.Overall,this study laid a theoretical foundation for developing cyasterone as an effective agent for the alleviation of osteoarthritis. | TENG Li SHEN Yue QU Yuhan YANG Longfei YANG Yuting JIAN Xi FAN Shengli ZHANG Lele FU Qiang | 2023 | Chinese Journal of Natural Medicines2023，21，2： | 0 |
| 7 | Smooth quadrotor trajectory generation for tracking a moving target in cluttered environments显示文摘In this paper,we present a trajectory generation method of a quadrotor,based on the optimal smoothing B-spline,for tracking a moving target with consideration of relative tracking pattern or limited field of view of the onboard sensor in cluttered environments.Compared to existing methods,safe flying zone,vehicle physical limits,and smoothness are fully considered to guarantee flight safety,kinodynamic feasibility,and tracking performance.To tackle the cluttered environments,a parallel particle swarm optimization algorithm is applied to find the feasible waypoints that the generated trajectory should be as close to as possible,with consideration of the target’s future state as well as obstacles to trade off the tracking performance and flight safety.Then,a sequential motion planning method,considering the above constraints,is applied and embedded into a cost function for solving the problem of robust tracking trajectory generation for the quadrotor via a convex optimization approach.The feasibility and effectiveness of the proposed method are verified by numerical simulations. | Lele XI Zhihong PENG Lei JIAO Ben M.CHEN | 2021 | Science China(Information Sciences)2021，64，7： | 0 |
| 8 | Minimax Q-learning design for H_(∞) control of linear discrete-time systems显示文摘The H_(∞)control method is an effective approach for attenuating the effect of disturbances on practical systems, but it is difficult to obtain the H_(∞)controller due to the nonlinear Hamilton-Jacobi-Isaacs equation, even for linear systems. This study deals with the design of an H_(∞)controller for linear discrete-time systems. To solve the related game algebraic Riccati equation(GARE), a novel model-free minimax Q-learning method is developed, on the basis of an offline policy iteration algorithm, which is shown to be Newton’s method for solving the GARE. The proposed minimax Q-learning method, which employs off-policy reinforcement learning, learns the optimal control policies for the controller and the disturbance online, using only the state samples generated by the implemented behavior policies. Different from existing Q-learning methods, a novel gradient-based policy improvement scheme is proposed. We prove that the minimax Q-learning method converges to the saddle solution under initially admissible control policies and an appropriate positive learning rate, provided that certain persistence of excitation(PE)conditions are satisfied. In addition, the PE conditions can be easily met by choosing appropriate behavior policies containing certain excitation noises, without causing any excitation noise bias. In the simulation study, we apply the proposed minimax Q-learning method to design an H_(∞)load-frequency controller for an electrical power system generator that suffers from load disturbance, and the simulation results indicate that the obtained H_(∞)load-frequency controller has good disturbance rejection performance. | Xinxing LI Lele XI Wenzhong ZHA Zhihong PENG | 2022 | Frontiers of Information Technology & Electronic Engineering2022，23，3： | 0 |
| 9 | Novel perspective in transplantation therapy of mesenchymal stem cells:targeting the ferroptosis pathway显示文摘Ex vivo culture-amplified mesenchymal stem cells(MSCs)have been studied because of their capacity for healing tissue injury.MSC transplantation is a valid approach for promoting the repair of damaged tissues and replacement of lost cells or to safeguard surviving cells,but currently the efficiency of MSC transplantation is constrained by the extensive loss of MSCs during the short post-transplantation period.Hence,strategies to increase the efficacy of MSC treatment are urgently needed.Iron overload,reactive oxygen species deposition,and decreased antioxidant capacity suppress the proliferation and regeneration of MSCs,thereby hastening cell death.Notably,oxidative stress(OS)and deficient antioxidant defense induced by iron overload can result in ferroptosis.Ferroptosis may inhibit cell survival after MSC transplantation,thereby reducing clinical efficacy.In this review,we explore the role of ferroptosis in MSC performance.Given that little research has focused on ferroptosis in transplanted MSCs,further study is urgently needed to enhance the in vivo implantation,function,and duration of MSCs. | YUZHU XU PAN FAN LEI LIU XUANFEI XU LELE ZHANG JIADONG WANG YUAO TAO XIAOLONG LI XI LI YUNTAO WANG | 2023 | Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)2023，24，2： | 0 |
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