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Design and implementation of Chinese libration point missions

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Science China(Information Sciences) 2023年第9期66卷 100-114页

作者： Lei liu Weiren wu yong liu Beijing Aerospace Control Center Lunar Exploration and Space Program Center

Libration points are vital for lunar and deep space explorations because of their unique positions and dynamics. This paper first traces the development of relevant missions since ISEE-3 and then presents the details of the trajectory design and implementation of four Chinese libration point missions in the lunar exploration project: the two Sun-Earth libration point missions by CHANG’E-2 and CHANG’E-5 and the two lunar libration point missions accomplished by CHANG’E-5T1 and Queqiao. The orbit technologies for these libration point missions are also elaborated on regarding trajectory design, maneuvering, and tracking,as well as orbit determination. This paper is expected to provide a reference for future cislunar and deep space exploration.

关键词： libration point three-body problem lunar exploration cislunar space flight scheme

Steel surface defect detection based on lightweight YOLOv7

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Optoelectronics Letters 2025年

作者： shi Tao wu Rongxin Zhu Wenxu Ma Qingliang School of Electrical Engineering and Automation， Tianjin University of Technology North China University of Science and Technology， College of Electrical Engineering Guangzhou Institute of Measurement and Testing Technology

Aiming at the problems of low detection efficiency and difficult positioning of traditional steel surface defect detection methods， a lightweight steel surface defect detection model based on YOLOv7 is proposed. First， a CSS Block module is proposed， which uses more lightweight operations to obtain redundant information in the feature map， reduces the amount of computation， and effectively improves the detection speed. Secondly， the improved SPPCSPC structure is adopted to ensure that the model can also pay attention to the defect location information while predicting the defect category information， obtain richer defect features. In addition， the convolution operation in the original model is simplified， which significantly reduces the size of the model and helps to improve the detection speed. Finally， using EIOU Loss to focus on high-quality Anchors， speed up convergence and improve positioning accuracy. Experiments were carried out on the NEU-DET steel surface defect dataset. Compared with the original YOLOv7 model， the number of parameters of this model was reduced by 40%， the FPS reached 112， and the average accuracy reached 79.1%.， the detection accuracy and speed have been improved， which can meet the needs of steel surface defect detection.

关键词：

Einstein Probe discovery of EP240408a: A peculiar X-ray transient with an intermediate timescale

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 222-240页

作者： Wenda Zhang Weimin Yuan Zhixing Ling yong Chen Nanda Rea Arne Rau Zhiming Cai Huaqing Cheng Francesco Coti Zelati Lixin Dai Jingwei Hu Shumei Jia Chichuan Jin Dongyue Li Paul O’Brien Rongfeng Shen Xinwen Shu Shengli Sun Xiaojin Sun Xiaofeng Wang Lei Yang Bing Zhang Chen Zhang Shuang-Nan Zhang yonghe Zhang Jie An David Buckley Alexis Coleiro Bertrand Cordier Liming Dou Rob Eyles-Ferris Zhou Fan Hua Feng Shaoyu Fu Johan P.U.Fynbo Lluis Galbany Saurabh W.Jha Shuaiqing Jiang Albert Kong Erik Kuulkers Weihua Lei Wenxiong Li Bifang liu Mingjun liu Xing liu Yuan liu Zhu liu Chandreyee Maitra Alessio Marino Itumeleng Monageng Kirpal Nandra Jeremy Sanders Roberto Soria Lian Tao Junfeng Wang Song Wang Tinggui Wang Zhongxiang Wang Qingwen wu Xuefeng wu Dong Xu Yanjun Xu Suijian Xue yongquan Xue Zijian Zhang Zipei Zhu Hu Zou Congying Bao Fansheng Chen Houlei Chen Tianxiang Chen Wei Chen Yehai Chen Yifan Chen Chenzhou Cui Weiwei Cui Yanfeng Dai Dongwei Fan Ju Guan Dawei Han Dongjie Hou Haibo Hu Maohai Huang Jia Huo Zhenqing Jia Bowen Jiang Ge Jin Chengkui Li Junfei Li Longhui Li Maoshun Li Wei Li Zhengda Li Tianying Lian Congzhan liu Heyang liu Huaqiu liu Fangjun Lu Laidan Luo Jia Ma Xuan Mao Haiwu Pan Xin Pan Liming Song Hui Sun Yunyin Tan Qingjun Tang Yihan Tao Hao Wang Juan Wang Lei Wang Wenxin Wang Yilong Wang Yusa Wang Qinyu wu Haitao Xu Jingjing Xu Xinpeng Xu Yunfei Xu Zhao Xu Changbin Xue Yulong Xue Ailiang Yan Haonan Yang Xiongtao Yang Yanji Yang Juan Zhang Mo Zhang Wenjie Zhang Zhen Zhang Zhen Zhang Ziliang Zhang Donghua Zhao Haisheng Zhao Xiaofan Zhao Zijian Zhao Hongyan Zhou Yilin Zhou Yuxuan Zhu Zhencai Zhu National Astronomical Observatories Chinese Academy of Sciences School of Astronomy and Space Sciences University of Chinese Academy of Sciences Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Institute of Space Sciences (ICE) CSIC Institut d’Estudis Espacials de Catalunya (IEEC) Max Planck Institute for Extraterrestrial Physics Innovation Academy for Microsatellites Chinese Academy of Sciences Department of Physics University of Hong Kong School of Physics and Astronomy University of Leicester School of Physics and Astronomy Sun Yat-sen University Department of Physics Anhui Normal University Shanghai Institute of Technical Physics Chinese Academy of Sciences Physics Department Tsinghua University Nevada Center for Astrophysics University of Nevada Las Vegas Department of Physics and Astronomy University of Nevada Las Vegas South African Astronomical Observatory Department of Astronomy University of Cape Town Department of Physics University of the Free State Université Paris Cité CNRS Astroparticule et Cosmologie Université Paris Cité CEA Paris-Saclay IRFU/DAp-AIM Department of Astronomy Guangzhou University Cosmic Dawn Center (DAWN) Niels Bohr Institute University of Copenhagen Department of Physics and Astronomy Rutgers the State University of New Jersey Institute for Cosmic Ray Research The University of Tokyo ESA/ESTEC Department of Astronomy School of Physics Huazhong University of Science and Technology INAF-Osservatorio Astrofisico di Torino Sydney Institute for Astronomy School of Physics The University of Sydney Department of Astronomy Xiamen University Institute for Frontiers in Astronomy and Astrophysics Beijing Normal University Department of Astronomy University of Science and Technology School of Astronomy and Space Sciences University of Science and Technology of China Institute of Deep Space Sciences Deep Space Exploration Laboratory Department of Astronomy School of Physics and Astronomy Yunnan University Shanghai Astronomical Observatory Chi

We report the discovery of a peculiar X-ray transient,EP240408a,by Einstein Probe （EP） and follow-up studies made with EP,Swift,NICER,GROND,ATCA and other ground-based multiwavelength *** new transient was first detected with Wide-field X-ray Telescope （WXT） on board EP on April 8th,2024,manifested in an intense yet brief X-ray flare lasting for *** flare reached a peak flux of 3.9×10-9erg cm-2s-1in 0.5-4 ke V,～300 times brighter than the underlying X-ray emission detected throughout the *** and more precise follow-up observations by EP/FXT,Swift and NICER confirmed the finding of this new *** X-ray spectrum is non-thermal in 0.5-10 ke V,with a power-law photon index varying *** X-ray light curve shows a plateau lasting for ～4 d,followed by a steep decay till becoming undetectable ～10 d after the initial *** on its temporal property and constraints from previous EP observations,an unusual timescale in the range of 7-23 d is found for EP240408a,which is intermediate between the commonly found fast and long-term *** counterparts have been found in optical and near-infrared,with the earliest observation at 17 h after the initial X-ray detection,suggestive of intrinsically weak emission in these *** demonstrate that the remarkable properties of EP240408a are inconsistent with any of the transient types known so far,by comparison with,in particular,jetted tidal disruption events,gamma-ray bursts,X-ray binaries and fast blue optical *** nature of EP240408a thus remains an *** suggest that EP240408a may represent a new type of transients with intermediate timescales of the order of～10 *** detection and follow-ups of more of such objects are essential for revealing their origin.

关键词： X-ray transients ${\bm~{Einstein~~Probe}}$

Hydrogen-bonded organic framework-ionic liquid composite quasisolid electrolyte for high-performance lithium battery

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Nano Research 2025年第1期18卷 332-340页

作者： Junmei Zhang Yatao wu Chenye Wang yong liu Zhirong Yang shiyue Zhou Wenpeng Li Wenjia wu Jingtao Wang School of Chemical Engineering Zhengzhou UniversityZhengzhou 450001China

Ionic liquids(ILs)hold great promise as highperformance electrolyte material due to their unique advantages including nonvolatility,high thermal stability and high ionic ***,the IL-based electrolytes always suffer from serious ion aggregation and high viscosity at low temperatures,leading to significantly decline in ionic ***,hydrogen-bonded organic framework-ionic liquid composite quasi-solid electrolyte(high temperature treatment(HT)-HOF-IL CQSE)was prepared through confining the IL electrolytes(ILEs)into the pore of HOF lamellar *** weak hydrogen bonding interactions within HOF nanosheets,together with the generated interactions between ILE and HOF,enable uniform and continuous distribution of ILE in HOF lamellar *** effectively inhibits the ion migration of ILE,which meanwhile serves as Li+transfer sites,affording high ionic conductivity of 5.7×10^(-5)S·cm-1 at-60 ℃,with high lithium-ion transference number of 0.69,whereas ILEs usually lose ionic conduction ability at such low *** assembled Li symmetrical cell can stably cycle at 0.2 mA·cm^(-2)and^(-2)0 ℃ for more than 1500 *** LiFePO_(4)|HT-HOF-IL CQSE|Li cell shows excellent cycling performance at 0.5 C at a wide temperature range of^(-2)0 to 60 ℃.This work may pave a new avenue for the development of high-performance IL-based composite electrolytes.

关键词： ionic liquid hydrogen-bonded organic framework low-temperature ionic conductivity lithium-ion transference number quasi-solid electrolyte

Colloid of Delaminated Layered Double Hydroxides:a Novel Type of LDH-based Catalyst

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Chemical Research in Chinese Universities 2010年第4期26卷 612-616页

作者： liu shi-yong Department of Chemistry Taizhou UniversityTaizhou 317000P.R.China Department of Chemistry Zhejiang UniversityHangzhou 310027P.R.China

The colloid of delaminated layered double hydroxides(LDHs), a new LDH-based catalyst, is described. The semi-heterogeneous delaminated colloidal MgPdA1-LDH, in which the total surface of catalytic site-bearing lamellae was rendered accessible for chemical reactivity, showed excellent catalysis toward Suzuki reaction. The turnover frequency of this catalyst for Suzuki reaction between bromobenzene and phenylboronic acid is about 8000 h^-1.

关键词： Layered double hydroxide(LDH) Colloid Delamination Suzuki reaction Semi-heterogeneous catalyst

Polyimide covalent organic frameworks as efficient solid-state Li^(+) electrolytes

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Science China Chemistry 2024年第5期67卷 1647-1652页

作者： Xu liu shi Wang Siqi liu Chengfang liu Xiangchun Li Jian wu Dazhi Li shihao Xu Chongyang liu Wen-yong Lai State Key Laboratory of Organic Electronics and Information Displays(SKLOEID) Institute of Advanced Materials(IAM)School of Chemistry and Life SciencesNanjing University of Posts&TelecommunicationsNanjing 210023China

Covalent organic frameworks(COFs) are attractive porous crystalline materials with extremely high stability, easy functionalization, and open channels, which are expected to be unique ion conductors/transporters in lithium ion batteries(LIBs). Despite recent advances, low ion conductivity and low transference number, resulting in low charging/discharging rate, low energy density, and short battery life, are the main issues that limit their direct application as solid electrolytes in LIBs. Here, we designed and synthesized a novel polyimide COF, namely, TAPA-PDI-COF, with abundant C=O groups, which has been successfully employed as high-performance solid electrolytes by doping TAPA-PDI-COF and succinonitrile(SN). Both the well-defined nanochannels of COFs and SN confined in the well-aligned channels restricted the free migration of anions, while C=O on COFs and CN groups of SN enhanced Li^(+) transport, thus achieving a high ion conductivity of 0.102 m S cm^(-1)at 80 °C and a high lithium-ion transference number of 0.855 at room temperature. According to density functional theory(DFT)calculations, Li-ion migration mainly adopted in-plane transport rather than the axial pathway, which may be due to the shorter hopping distances in the planar pathway. The results suggest an effective strategy for the design and development of all-solidstate ionic conductors for achieving high-performance LIBs.

关键词： lithium ion batteries(LIBs) covalent organic frameworks(COFs) solid-state ion conductors solid-state electrolytes ion conductivity

Oxygen vacancies enriched Ir/WOx catalysts for the directly chem-catalytic conversion of cellulose to ethanol

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Tungsten 2025年第1期7卷 88-99页

作者： Yu-Jing Weng Zhao-Ying Ding Ying-Chao Li Yuan-Feng wu Yuan-Yang Xu Rui Chen Xiao-Lei Zhao Hai-yong Wang Da-Lei Zhang Yu-Long Zhang Henan Key Laboratory of Coal Green Conversion and International Joint Laboratory of Coal Clean Utilization College of Chemistry and Chemical Engineering Henan Polytechnic University Key Laboratory of Renewable Energy Guangzhou Institute of Energy Conversion Chinese Academy of Sciences Liaoning Institute of Energy Technology

Tungsten and its oxides are highly versatile catalysts with unique properties that hold great promise for a wide array of applications,including biological pathways and chemical *** chemo-catalysis of cellulose to ethanol presents a promising avenue for ethanol synthesis with the potential for enhanced efficiency compared to conventional methods,offering a sustainable and carbon-neutral alternative to existing petrochemical and biological ***,Ir/WOxcatalysts enriched with oxygen vacancies were meticulously prepared and demonstrated remarkable catalytic performance in converting cellulose to ethanol directly in the presence of tungstic *** catalyst achieved a high ethanol yield of 66.5%under optimal reaction conditions,approaching the theoretical yield limit of traditional ethanol *** results revealed the presence of oxygen defects,Bronsted/Lewis acidity,and Ir nanoclusters on the catalyst surface,working synergistically to facilitate the cascade catalysis of cellulose hydrolysis,sugar retro-aldol condensation reaction,and C2 intermediate hydrodeoxygenation to *** situ Fourier transform infrared spectrometer analysis confirmed the catalyst's ability to enhance the adsorption and activation of ethylene glycol for ethanol *** manipulating subtle structural features,this study offers a fresh perspective on tungsten group catalyst design and underscores the importance of synergistic effects among catalytic sites for the efficient production of ethanol from cellulose.

关键词： Cellulosic ethanol Chem-catalysis Hydrogenolysis Retro-aldol condensation Tungsten

An ultrahigh strength steel produced through deformation-induced ferrite transformation and Q&P process

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Science China(Technological Sciences) 2012年第7期55卷 1827-1832页

作者： CHEN MingMing wu RiMing liu HePing WANG Li shi Jie DONG Han JIN xuejun School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China School of Material Science and Engineering North University of ChinaTaiyuan 030051China Baosteel Research and Development Technology Center Shanghai 201900China National Engineering Research Center of Advanced Steel Technology(NERCAST) Central Iron and Steel Research Institute(CISRI)Beijing 100081China

In this work,DIFT technology and Q&P process were combined in order to introduce ultrafine-grained ferrite into the matrix of martensite and retained austenite to develop a new kind of advanced high strength steel,and two kinds of steels were investigated by this novel combined *** newly designed process resulted in a sophisticated microstructure of a large amount of ferrite(about 5 m in diameter),martensite and a considerable amount of retained austenite for TRIP 780 *** ultimate tensile strength can reach about 1200 MPa with elongation above 16% for TRIP 780,that is much higher than the one solely treated by Q&P *** tests showed that both steels with the novel combined process achieved a good combination of strength and ductility,indicating that the new process is promising for the new generation of advanced high strength steels.

关键词： deformation induced ferrite transformation(DIFT) quenching and partitioning(Q&P) microstructure mechanical property

Tracking Control of Uncertain High-Order Nonlinear Systems with Odd Rational Powers and the Dead-Zone Input:A Direct Fuzzy Adaptive Control Method

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Journal of Systems Science & Complexity 2022年第5期35卷 1685-1699页

作者： liu Zhenguo shi Yuyuan wu Yuqiang School of Automation and Software Engineering Shanxi UniversityTaiyuan 030006China Institute of Automation Qufu Normal UniversityQufu 273165China

This work studies the tracking issue of uncertain nonlinear *** existence of odd rational powers,multiple unknown parameters and the dead-zone input add many difficulties for control *** procedures of the control design,by introducing an appropriate Lyapunov function,utilizing recursive control method and the inequality technique,some appropriate intermediate auxiliary control laws are designed under the hypothesis that nonlinear terms in the system are *** those nonlinear terms are unknown,by employing the powerful approximation ability of fuzzy systems,the intermediate auxiliary control laws are approximated recursively and used to construct the virtual ***,a new fuzzy adaptive tracking controller is constructed to ensure a small tracking error and the boundedness of all *** this paper,the overparameterization problem is significantly avoided since only two adaptive laws are *** and practical examples are used to verify the raised theory.

关键词： Dead-zone input direct fuzzy adaptive control uncertain systems