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| 1 | Modeling and Robust Backstepping Sliding Mode Control with Adaptive RBFNN for a Novel Coaxial Eight-rotor UAV显示文摘This paper focuses on the robust attitude control of a novel coaxial eight-rotor unmanned aerial vehicles(UAV) which has higher drive capability as well as greater robustness against disturbances than quad-rotor UAV. The dynamical and kinematical model for the coaxial eight-rotor UAV is developed, which has never been proposed before. A robust backstepping sliding mode controller(BSMC) with adaptive radial basis function neural network(RBFNN) is proposed to control the attitude of the eightrotor UAV in the presence of model uncertainties and external disturbances. The combinative method of backstepping control and sliding mode control has improved robustness and simplified design procedure benefiting from the advantages of both controllers. The adaptive RBFNN as the uncertainty observer can effectively estimate the lumped uncertainties without the knowledge of their bounds for the eight-rotor UAV. Additionally, the adaptive learning algorithm, which can learn the parameters of RBFNN online and compensate the approximation error, is derived using Lyapunov stability theorem. And then the uniformly ultimate stability of the eight-rotor system is proved. Finally, simulation results demonstrate the validity of the proposed robust control method adopted in the novel coaxial eight-rotor UAV in the case of model uncertainties and external disturbances. | Cheng Peng Yue Bai Xun Gong Qingjia Gao Changjun Zhao Yantao Tian | 2015 | IEEE/CAA Journal of Automatica Sinica2015，2，1： | 10 |
| 2 | The C_(6)D_(6)detector system on the Back-n beam line of CSNS显示文摘Introduction The neutron capture cross sections are very important in the field of nuclear device design and basic physics research.Hydrogen-free liquid scintillator such as C_(6)D_(6)detectors are widely used in the neutron capture cross-sectional measurements for the low neutron sensitivity and fast time response.The Back-n white neutron source at China Spallation Neutron Source is the first spallation white neutron source in China,and it is suitable for neutron capture cross-sectional measurement.Materials and methods A C_(6)D_(6)detector system was built in the Back-n experimental station.The pulse height weighting technique was used to determine the system’s detection efficiency.The response to gamma rays of the C_(6)D_(6)detector was measured,and the energy resolution function was determined.Monte Carlo simulation with Geant4 code was carried out to get the weighting function of this C_(6)D_(6)detector system.Additionally,the systematic uncertainty of the weighting function was also determined.Conclusion According to the experimental and simulation results,this C_(6)D_(6)detector system can be used to measure neutron capture cross section. | Jie Ren Xichao Ruan Jie Bao Guangyuan Luan Wei Jiang Qi An Huaiyong Bai Ping Cao Qiping Chen Yonghao Chen Pinjing Cheng Zengqi Cui Ruirui Fan Changqing Feng Minhao Gu Fengqin Guo Changcai Han Zijie Han Guozhu He Yongcheng He Yuefeng He Hanxiong Huang Weiling Huang Xiru Huang Xiaolu Ji Xuyang Ji Haoyu Jiang Hantao Jing Ling Kang Mingtao Kang Bo Li Lun Li Qiang Li Xiao Li Yang Li Yang Li Rong Liu Shubin Liu Xingyan Liu Yinglin Ma Changjun Ning Binbin Qi Zhaohui Song Hong Sun Xiaoyang Sun Zhijia Sun Zhixin Tan Hongqing Tang Jingyu Tang Pengcheng Wang Qi Wang Taofeng Wang Yanfeng Wang Zhaohui Wang Zheng Wang Jie Wen Zhongwei Wen Qingbiao Wu Xiaoguang Wu Xuan Wu Likun Xie Yiwei Yang Han Yi Li Yu Tao Yu Yongji Yu Guohui Zhang Jing Zhang Linhao Zhang Liying Zhang Qingmin Zhang Qiwei Zhang Xianpeng Zhang Yuliang Zhang Zhiyong Zhang Yingtan Zhao Liang Zhou Zuying Zhou Danyang Zhu Kejun Zhu Peng Zhu | 2019 | Radiation Detection Technology and Methods2019，3，3： | 1 |
| 3 | An exact penalty function method for nonlinear mixed discrete programming problems 显示文摘 | YU Changjun TEO K L BAI Yanqin | 2013 | Optimization Letters2013，7，1： | 1 |
| 4 | Backstepping sliding mode tracking control of quad-rotor under input saturation显示文摘Purpose–The quad-rotor is an under-actuation,strong coupled nonlinear system with parameters uncertainty,unmodeled disturbance and drive capability boundedness.The purpose of the paper is to design a flight control system to regulate the aircraft track the desired trajectory and keep the attitude angles stable on account of these issues.Design/methodology/approach–Considering the dynamics of a quad-rotor,the closed-loop flight control system is divided into two nested loops:the translational outer-loop and the attitude inner-loop.In the outer-loop,the translational controller,which exports the desired attitude angles to the inner-loop,is designed based on bounded control technique.In consideration of the influence of uncertain rotational inertia and external disturbance,the backstepping sliding mode approach with adaptive gains is used in the inner-loop.The switching control strategy based on the sign functions of sliding surface is introduced into the design procedure with respect to the input saturation.Findings–The validity of the proposed flight control system was verified through numerical simulation and prototype flight experiment in this paper.Furthermore,with relation to the flying,the motor speed is kept in the predetermined scope.Originality/value–This article introduces a new flight control system designed for a quad-rotor. | Xun Gong Yue Bai Zhicheng Hou Changjun Zhao Yantao Tian Qiang Sun | 2012 | International Journal of Intelligent Computing and Cybernetics2012，5，4： | 1 |
| 5 | Crystal MD:Molecular Dynamic Simulation Software for Metal with BCC Structure显示文摘Material irradiation effect plays an important role in material science.However,it is lack of high-throughput irradiation facility and process of evolution and development,which lead to lack of basic scientific theory about atomic scale materials design and development guidance.High-performance computing for simulation makes deeply understanding of micro-level-material possible.In this paper,a new data structure is proposed for the parallel simulation of metal materials evolution with crystal structure under irradiation defects.Compared with LAMMPS and IMD,which are two popular molecular dynamic simulation versions,our method takes much less memory on multi-core clusters. | He Bai Changjun Hu Xinfu He Boyao Zhang Jue Wang | 2015 | 国际计算机前沿大会会议论文集2015，，B12： | 0 |
| 6 | Detector development at the Back-n white neutron source显示文摘Purpose Back-n is a white neutron beamline at China spallation neutron source,which was established in the year of 2018.It is a powerful facility for nuclear data measurement,neutron detector calibration,and radiation effect research.Method A series of detectors were built for different experiments,including beam monitoring,beam profile measurement,neutron induced secondaries(fission fragments,light charged particles and gamma)cross section measurement,and neutron resonance radiography,etc.A common digitization electronics and a cluster-based DAQ were developed for these detector systems.Most detectors have been employed at Back-n and serviced for experiments from the beginning of the beamline running.Results and conclusion As an overview of detectors of Back-n,the details of the detector design and the experiment performing are described in this paper.Some developing systems,e.g.,MTPC and B-MCP,are also included. | Fan Ruirui Li Qiang Bao Jie Li Yang Liu Rong Jiang Wei Ren Jie Zhang Qiwei Cao Ping Gu Minhao Ren Zhizhou Yi Han Tang Jingyu An Qi Bai Haofan Bai Jiangbo Chen Qiping Chen Yonghao Chen Zhen Cui Zengqi Fan Anchuan Feng Changqing Feng Fanzhen Gao Keqing Han Changcai Han Zijie He Guozhu He Yongcheng Hong Yang Hu Yiwei Huang Hanxiong Jia Weihua Jiang Haoyu Jiang Zhijie Jin Zhengyao Kang Ling Li Bo Li Chao Li Gong Li Jiawen Li Xiao Liu Jie Liu Shubin Luan Guangyuan Ning Changjun Qi Binbin Ruan Xichao Song Zhaohui Sun Kang Tan Zhixin Tang Shengda Wang Pengcheng Wang Zhaohui Wen Zhongwei Wu Xiaoguang Wu Xuan Xie Likun Yang Yiwei Yu Yongji Zhang Guohui Zhang Linhao Zhang Mohan Zhang Xianpeng Zhang Yuliang Zhang Yue Zhang Zhiyong Zhao Maoyuan Zhou Luping Zhou Zhihao Zhu Kejun The CSNS Back-n Collaboration | 2023 | Radiation Detection Technology and Methods2023，7，2： | 0 |
| 7 | Study on Saccharification of Saccharum spontaneum L. by Sulphuric Acid Hydrolysis显示文摘In order to improve the saccharification rate by acid hydrolysis in the technique for production of ethanol from biomass,in this study,Saccharum spontaneum L. was used as the experimental material to investigate the rules and technological conditions for two-step acid-hydrolysis saccharification by single factor experiment and orthogonal experiment. According to the results,concentrated sulfuric acid hydrolysis was the first step,with the liquid-solid ratio of 42∶ 1,sulfuric acid concentration of 70%,hydrolysis time of 20 min,and hydrolysis temperature of 55 ℃; dilute sulphuric acid hydrolysis was the second step,with the liquidsolid ratio of 115∶ 1,sulfuric acid concentration of 5. 5%,hydrolysis time of 155 min,and hydrolysis temperature of 100 ℃. In two-step acid hydrolysis process,the yield of reducing sugar was 48. 78%. The results indicated that two-step acid-hydrolysis saccharification required mild conditions,simple operation and low cost,and led to high reducing sugar yield,exhibiting a broad application prospect. | Jianle LIU Changjun BAI Linling YAN Qinglin JIA Yu ZHANG Hubiao YANG | 2014 | Agricultural Biotechnology2014，3，6： | 0 |
| 8 | Energy Productivity Potential Assessment of Saccharum spontaneum L. Germplasm Resources显示文摘[Objective]The energy productivity potential of Saccharum spontaneum L.germplasm resources as energy plants was discussed in this paper.[Method]The energy productivity potential of Saccharum spontaneum L.germplasm resources collected from the wild was assessed from the aspects of cellulose,semicellulose,lignin and crude ash contents and caloric value.[Result]The total content of cellulose and semicellulose ranged from 41.75%to 69.13%,the lignin content ranged from 2.16%to 11.75%,the crude ash content ranged from 4.79%to 9.34%and the caloric value ranged from 16.00 to 17.69 MJ/kg among the 30 Saccharum spontaneum L.germplasms.Compared to other plants,Saccharum spontaneum L.had higher contents of cellulose and semicellulose,a higher caloric value but lower contents of lignin and crude ash.[Conclusion]From the perspective of producing fuel ethanol with lignocellulose,Saccharum spontaneum L.has a great potential for development as an energy plant. | Jianle LIU Changjun BAI Linling YAN | 2014 | Agricultural Science & Technology2014，15，12： | 0 |
| 9 | Influence Mechanism of Process Parameters on Relative Density, Influence Mechanism of Process Parameters on Relative Density, Microstructure, and Mechanical Properties of Low Sc-Content Al-Mg-Sc-Zr Alloy Fabricated by Selective Laser Melting显示文摘Additive manufacturing of Al-Mg-Sc-Zr alloys is a promising technique for the fabrication of lightweight components with complex shapes.In this study,the effect of the process parameters of selective laser melting(SLM)on the surface morphology,relative density,microstructure,and mechanical properties of Al-Mg-Sc-Zr high-strength aluminum alloys with low Sc content was systematically investigated.The results show that the energy density has an important effect on the surface quality and densification behavior of the Al-Mg-Sc-Zr alloy during the SLM process.As the energy density increased,the surface quality and the number of internal pores increased.However,the area of the fine-grained region at the boundary of the molten pool gradually decreased.When the laser energy density was set to 151.52 J/mm3,a low-defect sample with a relative density of 99.2%was obtained.After heat treatment,the area of the fine grains at the boundary increased significantly,thereby contributing to the excellent mechanical properties.The microstructure was characterized by a unique“fan-shaped”heterogeneous structure.As the energy density increased,the microhardness first increased and then decreased,reaching a maximum value of 122 HV0.3.With the optimized process parameters,the yield strength(YS),ultimate tensile strength(UTS),and elongation of the as-built Al-Mg-Sc-Zr alloys were 346.8±3.0 MPa,451.1±5.2 MPa,14.6%±0.8%,respectively.After heat treatment at 325°C for 8 h,the hardness increased by 38.5%to 169 HV0.3,and the YS and UTS increased by 41.3%and 18.1%,respectively,to 490.0±9.0 MPa and 532.7±7.8 MPa,respectively,while the elongation slightly decreased to 13.1%±0.7%. | Di Wang Yongwei Feng Linqing Liu Xiongmian Wei Yongqiang Yang Pan Yuan Yang Liu Changjun Han Yuchao Bai | 2022 | Chinese Journal of Mechanical Engineering(Additive Manufacturing Frontiers)2022，1，4： | 0 |
| 10 | A new piecewise quadratic approximation approach for L_0 norm minimization problem显示文摘In this paper, we consider the problem of finding sparse solutions for underdetermined systems of linear equations, which can be formulated as a class of L_0 norm minimization problem. By using the least absolute residual approximation, we propose a new piecewis, quadratic function to approximate the L_0 norm.Then, we develop a piecewise quadratic approximation(PQA) model where the objective function is given by the summation of a smooth non-convex component and a non-smooth convex component. To solve the(PQA) model,we present an algorithm based on the idea of the iterative thresholding algorithm and derive the convergence and the convergence rate. Finally, we carry out a series of numerical experiments to demonstrate the performance of the proposed algorithm for(PQA). We also conduct a phase diagram analysis to further show the superiority of(PQA) over L_1 and L_(1/2) regularizations. | Qian Li Yanqin Bai Changjun Yu Ya-xiang Yuan | 2019 | Science China Mathematics2019，62，1： | 0 |
| 11 | Nutritional Value Evaluation of Saccharum spontaneum L. Germplasm Resources显示文摘The contents of dry matter, crude fat, crude protein, neutral detergent fiber, acid detergent fiber, crude ash, Ca and P in 43 Saccharum spontaneum L.germplasms during the vegetative period were determined. Among them, the crude protein, crude fat, neutral detergent fiber, acid detergent fiber, P and Ca contents were treated as the judging indicators. The nutritional value evaluation was carried out with the analytic hierarchy process(AHP). The results showed A49(Guangxi)had the highest nutritional value. Its dry matter, crude protein, crude fat, crude ash,neutral detergent fiber, acid detergent fiber, Ca and P contents were 32.35%,7.20%, 4.06%, 8.07%, 75.81%, 50.72%, 0.23% and 0.16% respectively. While A3(Guangdong) had the lowest nutritional value. Its dry matter, crude protein, crude fat, crude ash, neutral detergent fiber, acid detergent fiber, Ca and P contents were32.24%, 4.62%, 0.51%, 6.38%, 46.40%, 40.02%, 0.15% and 0.09% respectively.The crude protein content differed significantly among different germplasms. A48 had the highest crude protein content(9.11%), and A14 had the lowest crude protein content(3.72%). Based on the evaluation results, the 43 Saccharum spontaneum L.germplasms were divided into 3 groups: high-nutritional value type, moderate-nutritional value type and low-nutritional value type. We hoped to provide a theoretical reference for the application of Saccharum spontaneum L. as a forage grass. | Jianle LIU Changjun BAI Linling YAN Shimeng CHEN Yu ZHANG Hubiao YANG | 2014 | Agricultural Science & Technology2014，15，11： | 0 |
| 12 | The Extension and Utilization of the Pasture in the Tropical Area of China显示文摘This paper summarized the research and development of pasture in the tropical areas,and simply generalized the problems and methods for improvement and expected the advancement of the tropical pasture. | Yu ZHANG Changjun BAI | 2015 | Agricultural Science & Technology2015，16，11： | 0 |
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