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Precise orbit determination for TH02-02 satellites based on BDS3 and GPS observations

Chinese Journal of Aeronautics 2023年第5期36卷 475-485页

作者： Houzhe ZHANG Bing JU Defeng GU Ying LIU Kai SHAO Xiaojun DUAN Zhiyong HUANG College of Science National University of Defense TechnologyChangsha 410073China National Key Laboratory of Science and Technology on Aerospace Flight Dynamics Beijing Aerospace Control CenterBeijing 100094China MOE Key Laboratory of TianQin Mission TianQin Research Center for Gravitational PhysicsFrontiers Science Center for TianQinCNSA Research Center for Gravitational WavesSun Yat-sen University(Zhuhai Campus)Zhuhai 519082China School of Artificial Intelligence Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082China School of Physics and Astronomy Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082China Information Engineering University Zhengzhou 450001China

The Tianhui-202(TH02-02)satellite formation,as a supplement to the microwave mapping satellite system Tianhui-201(TH02-01),is the first Interferometric Synthetic Aperture Radar(InSAR)satellite formation-flying system that supports the tracking of BeiDou global navigation Satellite system(BDS3)new B1C and B2a ***,the twin TH02-02 satellites also support the tracking of Global Positioning System(GPS)L1&L2 and BDS B1I&B3I *** the spaceborne receiver employs two independent boards to track the Global Navigation Satellite System(GNSS)satellites,we design an orbit determination strategy by estimating independent receiver clock offsets epoch by epoch for each GNSS to realize the multi-GNSS data fusion from different *** performance of the spaceborne receiver is evaluated and the contribution of BDS3 to the kinematic and reduced-dynamic Precise Orbit Determination(POD)of TH02-02 satellites is *** tracking data onboard shows that the average number of available BDS3 and GPS satellites are 8.7 and 9.1,*** carrier-to-noise ratio and carrier phase noise of BDS3 B1C and B2a signals are comparable to those of ***,strong azimuth-related systematic biases are recognized in the pseudorange multipath errors of B1C and *** pseudorange noise of BDS3 signals is better than that of GPS after eliminating the multipath errors from specific *** the GPS-based reduced-dynamic orbit with single-receiver ambiguity fixing technique as a reference,the results of BDS3-only and BDS3+GPS combined POD are *** Root Mean Square(RMS)of orbit comparison of BDS3-based kinematic and reduced-dynamic POD with reference orbit are better than 7 cm and 3 cm in three-Dimensional direction(3D).The POD performance based on B1C&B2a data is comparable to that based on B1I&*** precision of BDS3+GPS combined kinematic orbit can reach up to 3 cm(3D RMS),which has a more than 25%improvement relative to the GPS-only *** addi

关键词： BDS3 Multi-GNSS Precise orbit determination Spaceborne GNSS receiver TH02-02

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Stability of potentially toxic elements in municipal sludge biochars modified by MgCl2 and phosphate

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Waste Disposal and Sustainable Energy 2023年第1期5卷 13-23页

作者： Qiqi Huang Siqi Chen Jinhao Lin Jingzi Beiyuan Jin Wang Juan Liu Yundang Wu Xiaolian Wu Fuhua Li Wenbing Yuan Chengrong Nie School of Environmental and Chemical Engineering Foshan UniversityFoshan528000China School of Food Science and Technology Foshan UniversityFoshan528000China Foshan Engineering and Technology Research Center for Contaminated Soil Remediation School of Environmental and Chemical EngineeringFoshan UniversityFoshan528000China School of Environmental Science and Engineering Key Laboratory of Water Quality and Conservation in the Pearl River DeltaMinistry of EducationGuangzhou UniversityGuangzhou510006China Guangdong Key Laboratory of Integrated Agro-Environmental Pollution Control and Management Institute of Eco-Environmental and Soil SciencesGuangdong Academy of SciencesNational-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South ChinaGuangzhou510650China

Municipal wastewater sludge can be pyrolyzed as biochars to better use nutrients and stabilize carbon compared with other typical technologies,such as landfill and ***,sludge-derived biochars might contain large amounts of potentially toxic elements(PTEs),such as Zn,Cu,Cr,Ni,Pb,and *** stability of PTEs in biochars might be improved by higher pyrolytic temperatures,which can be further improved by different ***,PO4-modification at 300°C and Cl-modification at 700°C were carried out,respectively,to enhance the stability of *** leaching tests have been performed to assess the stability of PTEs in biochars,including the synthetic precipitation leaching procedure(SPLP),toxicity characteristic leaching procedure(TCLP),diethylenetriamine pentaacetate(DTPA)extraction,and in vitro simple bioaccessibility extraction test(SBET).The morphological structure,elemental mapping,and mineral formation of the pristine and modified biochars were studied by scanning electron microscopy–energy-dispersive X-ray spectroscopy(SEM–EDS)and X-ray diffraction(XRD).Our results suggested that the leachability,mobility,plant-availability,and bioaccessibility of most PTEs were decreased by pyrolysis,yet the total contents of PTEs were elevated,especially at 700°***,modification by phosphates and MgCl2 enhanced the stability of PTEs in ***,it should be noted that higher bioaccessibility of PTEs was observed in biochars of P-modification than Cl-modification,which is associated with the dissolution of phosphate precipitates under acidic conditions(pH<2).Additionally,Cl-modification leads to higher plant-available Zn and Cu and bioaccessible Zn compared with the unmodified biochar produced at 700°C.

关键词： Biochar modification Sludge biochar Sewage sludge utilization Chlorination Pyrolysis Heavy metals

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A review of novel ternary nano-layered MAX phases reinforced AZ91D magnesium composite

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Journal of Magnesium and Alloys 2022年第6期10卷 1457-1475页

作者： Wantong Chen Wenbo Yu Chaosheng Ma Guozheng Ma Laiqi Zhang Haidou Wang Center of Materials Science and Engineering School of Mechanical and Electronic Control EngineeringBeijing Jiaotong UniversityBeijing 100044China National Key Lab for Remanufacturing Army Academy of Armored ForcesBeijing 100072China State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing100083China

In recent decades, the demand for lightweight and high specific strength materials brings about the development of magnesium matrix composites. Different from some traditional binary ceramic particles, such as SiC, Al_(2)O_(3), the novel ternary nano-layered M_(n+1)AX_(n)(MAX)phase carbide or nitride ceramics exhibit metal-like properties and self-lubricate capacity(where “M” is an early transition metal, “A” belongs to the group A element, “X” is C or/and N, and n = 1–3). Ti_(2)AlC, as the representative of the MAX phase, was interestingly introduced into the magnesium matrix. Layered Ti_(2)AlC MAX phased reinforced AZ91D magnesium composites manufactured through the stir casting exhibit sufficient deformation capacity due to unique deformation behaviors of MAX, namely delamination and the formation of kinking band. Further,the Ti_(2)AlC-AZ91D composites exhibit a distinctive characteristic in strengthening mechanism, damping mechanism and tribological capacity due to the other special properties of MAX phase, such as self-lubricated property. Accordingly, to give a comprehensive understanding, we overviewed the fabrication process, microstructural characterization, mechanical properties, damping property and tribological capacity on these composites. In order to understand the A-site effect in MAX phase on the microstructure, we introduced another representative Ti_(3)SiC_(2)MAX phase to explain the interfacial evolution. In addition, due to the high aspect ratio of MAX, MAX particles could be orientationally regulated in Mg matrix by plastic deformation such as hot extrusion. Herein, we discussed the anisotropic mechanical and physical properties of the textured composites produced by hot extrusion. Moreover, the potential applications and future development trends of MAX phases reinforced magnesium matrix composites were also given and prospected.

关键词： Ternary MAX phases Magnesium composite Damping Mechanical properties Anisotropic Tribological capacity

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Research on the Effect of Visual Warming Information Presentation on Attention in Fighter Tracking Task

Research on the Effect of Visual Warming Information Present...

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2023 IEEE International Conference on Industrial Engineering and Engineering Management, IEEM 2023

作者： Zhu, Jingxin Qu, Mengyuan Tian, Jingze Wang, Yiyan Huang, Jianwei Yang, Wenjun Niu, Yafeng School of Mechanical Engineering Southeast University Nanjing China Xiamen Municipal Smart City Technology Co. Ltd. Xiamen China National Key Laboratory of Science and Technology on Aircraft Control Xi'an China

ISBN: (纸本)9798350323153

The influence of several visual warning presentation techniques on attention during the fighter tracking task is examined in this research. Concentrate on analyzing the visual channel information form used in alarm systems, as well as how tracking tasks and alert reaction tasks are conveyed by this information. To investigate the ideal visual angle of separation (VAS) and flashing frequency of the visual warning information of the fighter tracking task, the tracking inaccuracy of the tracking task, the reaction time and response accuracy of the warning response task, and the subjective workload of the participants were measured. The pilot performs well in all areas when there is a visual saccade warning signal with a VAS of 10°;for minor warning content, when the VAS is at 20° or 30°,the flashing frequency of 5Hz will not result in a significant load experience, and interference with the primary task can enhance the performance of warning and attention. © 2023 IEEE.

关键词： Attention resource theory Fighter tracking task Human-computer interaction

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Gearbox Fault Diagnosis Based on Fast Iterative Filtering Decomposition and Modified Permutation Entropy

Gearbox Fault Diagnosis Based on Fast Iterative Filtering De...

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TEPEN International Workshop on Fault Diagnostics and Prognostics, TEPEN-IWFDP 2024

作者： Han, Tao Gong, Peiping Hu, Qingsen Gong, Jiancheng Liu, Wuqiang Training Base Army Engineering University of PLA Xuzhou221000 China College of Field Engineering Army Engineering University of PLA Nanjing210000 China National Defense Key Laboratory of Science and Technology on Vessel Integrated Power Technology Naval University of Engineering Wuhan430000 China

ISBN: (纸本)9783031702341

Gearbox is an important mechanical component. After the gearbox fails, the vibration signal is nonlinear and nonstationary. In addition, due to the prominent impact of both disruptive noise and components, it can be observed that the fault-related information embedded within the vibration signal is very weak, In order to diagnose gearbox faults accurately and quickly, a fault feature extraction model founded on fast iterative filter decomposition (FIFD) and modified permutation entropy (MPE) is established. Firstly, the vibration signal is decomposed into several intrinsic mode function (IMF) by FIFD with considerable computational efficiency. Subsequently, the IMF components with strong correlation were selected as main components by a newly proposed evaluation index called correlation energy kurtosis (CEK). Then, the fault information is extracted by modified permutation entropy (MPE), which introduced mean square value into entropy calculation to construct fault characteristics. Finally, random forest (RF) classification model is used to intelligently diagnose the fault type. It is verified by operating a set of experimental data from a fault gearbox that the proposed method enjoys a high accuracy of fault diagnosis and identify the fault type of the gearbox quickly. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2024.

关键词： Evaluation Index Fast Iterative Fault Diagnosis Filtering Decomposition Gearbox Modified Permutation Entropy

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Enhanced baseline determination for formation flying LEOs by relative corrections of phase center and code residual variations

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Chinese Journal of Aeronautics 2022年第2期35卷 185-194页

作者： Bin YI Defeng GU Bing JU Kai SHAO Houzhe ZHANG College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China TianQin Research Center for Gravitational Physics and School of Physics and Astronomy Sun Yat-sen University(Zhuhai Campus)Zhuhai 519082China National Key Laboratory of Science and Technology on Aerospace Flight Dynamics Beijing Aerospace Control CenterBeijing 100094China

Formation flying Low Earth Orbiters(LEOs)are important for implementing new and advanced concepts in Earth observation *** Baseline Determination(PBD)is a prerequisite for LEOs to complete specified mission *** is usually performed based on space-borne GNSS data,the relative corrections of phase center and code residual variations play crucial roles in achieving the best relative orbit ***,the influences of antenna Relative Phase Centre Variations(RPCVs)and Single-Difference(SD)Melbourne-Wu¨bbena(MW)Combination Residuals Variations(SD MWVs)on PBD are *** methods were tested using flight data from Gravity Recovery And Climate Experiment(GRACE)and GRACE Follow-On(GRACE-FO).Results showed that the maximum values for RPCVs and SD MWVs were 14 mm and 0.32 cycles,***,the RPCVs correction significantly enhanced the baseline accuracy;the K-Band Ranging(KBR)measurement consistency improved by 30.1%and 37.5%for GRACE and GRACE-FO,*** application of SD MWVs further improved the accuracy and reliability of PBD *** GRACE,the ambiguities fixing success rate increased from 85.1%to 97.9%and a baseline consistency of 0.57 mm was achieved for the KBR *** was found that the correction of both RPCVs and SD MWVs reduced the carrier phase observation minus computation residuals from double-difference ionosphere-free *** addition,in-flight data processing demonstrated that RPCVs and SD MWVs estimations for the current period could be used for the previous and subsequent periods.

关键词： Ambiguity resolution Formation flying Precise baseline determination(PBD) Relative phase centre variations(RPCVs)estimation SD MW combination residuals variations(SD MWVs)estimation

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Effects of yellow and green light stress on emergence,feeding and mating of Anomala corpulenta Motschulsky and Holotrichia parallela Motschulsky(Coleoptera:Scarabaeidae)

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International Journal of Agricultural and Biological Engineering 2023年第1期16卷 81-87页

作者： Yueli Jiang Qiuying Huang Guoshu Wei Zhongjun Gong Tong Li Jin Miao Ruijie Lu Shiqiong Mei Xueqin Wang Yun Duan Yuqing Wu Chuantao Lu Henan Key Laboratory of Crop Pests Control Key Laboratory of Integrated Pest Management on Crops in Southern Region of NorthChinaMinistry of AgricultureInstitute of Plant ProtectionHenan Academy of Agricultural SciencesZhengzhou 450002China College of Plant Science and Technology Huazhong Agricultural UniversityWuhan 430070China College of Plant Protection Hebei Agricultural UniversityBaoding 071000HebeiChina

Light is one of the key environmental factors for insects to *** light sources different from natural environmental light can cause light stress in *** and green light stress can interfere with the diurnal rhythm of nocturnal moths and their mating,oviposition,and adult *** scarabaeid beetles Anomala corpulenta Motschulsky and Holotrichia parallela Motschulsky are widely distributed,and they are very harmful underground *** order to clarify the effects of light stress on their behaviors,individuals of both species were exposed to yellow light(565-585 nm)and green light(525-545 nm),with different light intensity gradients of yellow light in a laboratory *** short-term light stress treatment of *** and *** was carried out at *** number of beetles emerging per half an hour was recorded,and mating pairs and feeding activity in 24 h were *** results showed that yellow and green light stress significantly changed the rhythm and reduced the rate of beetle emergence in the two beetle species ***,the peak emergence activity was delayed and the feeding and mating activities were significantly *** treated with different intensities of yellow light,it was found that the rate of emergence of *** under 10 lx was close to the control *** rate of emergence in *** was significantly lower than the control groups before 0:00,in the 60 lx and 110 lx treatment groups,but after 0:00,the emergence rate of *** was significantly higher in the 60 lx and 110 lx treatment groups than other ***,the emergence rhythms in the three light intensity treatment groups are basically the same as in the control *** feeding amount and mating beetles in the three light intensity treatment groups were significantly lower than in the control *** were no significant differences in the three *** results show that light stress above 10 l

关键词： yellow and green light Anomala corpulenta Motschulsky Holotrichia parallela Motschulsky emergence rhythm feeding mating

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The Robust Adaptive controller for Hypersonic Flight Vehicle Based on ADRC and PSMC

The Robust Adaptive Controller for Hypersonic Flight Vehicle...

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2022 Chinese Automation Congress, CAC 2022

作者： Mo, Jiaxuan Liu, Xiaodong Lu, Kunfeng Jiang, Sirong Beijing Aerospace Automatic Control Institute National Key Laboratory of Science and Technology on Aerospace Intelligent Control Beijing China China Academy of Launch Vehicle Technology Beijing China

ISBN: (纸本)9781665465335

Considering the nonlinearity, uncertainty and difficulties of modelling for hypersonic flight vehicles (HFV), this paper proposes a robust adaptive controller for HFV attitude control. Based on the longitudinal model for HFV during the phase of gliding with both external disturbance and internal parameter perturbation, the control-oriented affine nonlinear model for attitude control has been established in this paper. According to this model, this paper involves tracking differentiator (TD), an adaptive nonlinear extended state observer (ANLESO) into the predictive sliding mode controller (PSMC). An adjustment coefficient, an improved nonlinear function and a sigmoid tracking differentiator are included in the ANLESO to enhance the accuracy of estimation. Numerical simulation results verify that the proposed controller is both applicable and robust for HFV attitude tracking. It is shown that the proposed controller leads to better performance when tracking the desired command even exerted with disturbance. © 2022 IEEE.

关键词： Attitude control

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Terahertz wide range phase manipulation with super-resolution precision by near-field nonlinear coupling of a digitally coding needle meta-chip

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Photonics Research 2024年第9期12卷 1868-1876页

作者： HUAJIE LIANG HONGXIN ZENG TIANCHI ZHOU HANYU ZHAO SHAOKANG GU LIN ZOU TAO JIANG LAN WANG FENG LAN SHIXIONG LIANG ZHIHONG FENG ZIQIANG YANG YAXIN ZHANG Huzhou Key Laboratory of Terahertz Integrated Circuits and Systems Yangtze Delta Region Institute(Huzhou)University of Electronic Science and Technology of ChinaHuzhou 313001China Sichuan Engineering Center of Integrated Optoelectronic&Radio Meta-chips School of Electronic Science and EngineeringUniversity of Electronic Science and Technology of ChinaChengdu 611731China National Key Laboratory of Solid-State Microwave Device and Circuit Hebei Semiconductor Research InstituteShijiazhuang 050051China Zhangjiang Laboratory Shanghai 201204China

Achieving ultra-precise wide-range terahertz(THz)phase modulation has been a long-standing challenge due to the short wavelength and sensitive phase of THz *** paper proposes a new ultra-high precision phase control method employing a digitally coding needle meta-chip embedded in a *** needle tips can effectively couple THz waves via the charge aggregation *** controlling the Schottky diodes with coding voltages,the charge on each meta-structure part can be tuned to form strong or weak resonances,producing phase ***,the massive charge accumulation and the sub-λ∕10 distance between needle tips lead to near-field coupling among multiple ***,modulation of the charge at each tip by multichannel coding voltages enables combined resonance tuning of THz waves,yielding a nonlinear phase ***,a meta-chip containing 8 needle meta-structure units is demonstrated,which breaks through the precision limitation of independent units and realizes super-resolution precision phase modulation similar to super-resolution *** the 213–227 GHz band,we achieve a phase shift exceeding 180°with 11.25°accuracy,and a phase shift of over 170°with an accuracy of 3°.This super-resolution phase modulation strategy provides a new idea for future highprecision applications of THz integrated systems.

关键词： tuning phase resolution

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Nested Saturated control of Uncertain Complex Cascade Systems Using Mixed Saturation Levels

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1163-1174页

作者： Meng Li Zhigang Zeng Wuhan National Laboratory for Optoelectronics Wuhan 430074 School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074 Key Laboratory of Image Processing and Intelligent Control of Education Ministry of China Wuhan 430074China

This study addresses the problem of global asymptotic stability for uncertain complex cascade systems composed of multiple integrator systems and non-strict feedforward nonlinear systems. To tackle the complexity inherent in such structures, a novel nested saturated control design is proposed that incorporates both constant saturation levels and state-dependent saturation levels. Specifically, a modified differentiable saturation function is proposed to facilitate the saturation reduction analysis of the uncertain complex cascade systems under the presence of mixed saturation levels. In addition, the design of modified differentiable saturation function will help to construct a hierarchical global convergence strategy to improve the robustness of control design scheme. Through calculation of relevant inequalities, time derivative of boundary surface and simple Lyapunov function,saturation reduction analysis and convergence analysis are carried out, and then a set of explicit parameter conditions are provided to ensure global asymptotic stability in the closed-loop systems. Finally, a simplified system of the mechanical model is presented to validate the effectiveness of the proposed method.

关键词： method saturation differentiable

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