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Fast Position and Velocity Determination for Pulsar Navigation Using NML and LSM

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Chinese Journal of Electronics 2017年第6期26卷 1325-1329页

作者： liu Jin WU Jin XIONG ling FANG Jiancheng liu Gang College of Information Science and Engineering Wuhan University of Science and Technology School of Instrumentation Science and Opto-electronics Engineering Beihang University

To reduce the computational cost, a Fast position and velocity joint determination(FPVD) method based on the Near-maximum likelihood(NML) and the Least square method(LSM) is proposed for X-ray pulsar navigation. Considering the fact that the Doppler effects caused by the velocity of the spacecraft alters the X-ray pulse Time-of-arrival(TOA), we adopt the NML to obtain multi-TOAs, and then utilize the LSM to estimate the variation of TOAs instead of the pulsar profile distortion adopted by the Maximum-likelihood(ML) estimation method. Finally, according to the variation value and TOAs, the position and velocity information of the spacecraft are calculated. The simulation results have demonstrated that the FPVD method is far faster than the ML estimation method, and its accuracy approaches the CramerRao lower bound(CRLB).

关键词： Velocity determination Pulsar Maximum likelihood Least square method

Adaptive Fuzzy Dynamic Surface Control of Flexible-Joint Robot Systems With Input Saturation

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IEEE/CAA Journal of Automatica Sinica 2019年第1期6卷 97-107页

作者： Song ling Huanqing Wang Peter X.liu the School of Mechanical Electronic and Control EngineeringBeijing Jiaotong University the Department of Mathematics Bohai University IEEE the Department of Systems and Computer Engineering Carleton University

In this paper, we propose an adaptive fuzzy dynamic surface control(DSC) scheme for single-link flexible-joint robotic systems with input saturation. A smooth function is utilized with the mean-value theorem to deal with the difficulties associated with input saturation. An adaptive DSC design with an auxiliary first-order filter is used to solve the "explosion of complexity"problem. It is proved that all the signals in the closed-loop system are semi-globally uniformly ultimately bounded, and the tracking error eventually converges to a small neighborhood around zero. The main advantage of the proposed method is that only one adaptation parameter needs to be updated,which reduces the computational burden significantly. Simulation results demonstrate the feasibility of the proposed scheme and the comparison results show that the improved DSC method can reduce the computational burden by almost two thirds in comparison with the standard DSC method.

关键词： Adaptive fuzzy control dynamic surface control (DSC) flexible-joint (FJ) robots single-link tracking control

Special Topic:Up-Conversion Luminescence

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Journal of Analysis and Testing 2023年第4期7卷 325-326页

作者： Qian liu ling Huang College of Chemistry Nankai UniversityTianjin 300071China Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200438China

Photon upconversion is the conversion of low-energy photons(long wavelengths)into high-energy photons(short wavelengths).Single-particle,single-cell bioimaging with high temporal-spatial resolution and biological backgroundfree has already been accomplished via photon upconversion,utilizing the unique advantages of upconversion luminescence.

关键词： utilizing accomplished particle

Carbothermal reduction process of the Fe-Cr-O system

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International Journal of Minerals,Metallurgy and Materials 2013年第10期20卷 931-940页

作者： Yan-ling Zhang Yang liu Wen-jie Wei State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing

Understanding the reduction behaviors and characteristics of the end products of Fe-Cr-O systems is very important not only for maximizing the recovery of metals from stainless steel dust but also for the subsequent reuse in metallurgical process. The present work first predicted the possible products thermodynamically when FeCr204 was reduced by C. The reduction behaviors by graphite of three kinds of Fe-Cr-O systems, i.e., FeCr204, Fe203q-Cr203, and Feq-Cr203, were then investigated in 1350-1550℃. Further, the microstructures of final products and element distribution conditions were examined. The results suggest that, thermodynamically, the mass of products for the carbothermal reduction of FeCr204 is a strong function of temperature, and the initial carbon content is used. More Fe-Cr-C solution and less residual carbon content are obtained at higher temperatures and lower no：no ratios （the initial molar ratio of C to O in the sample）. Experimental data show that the sample amount tends to affect the reduction rate, and the residual carbon content strongly depends on nc：no. With regard to the phases present in products during the reaction process, metal carbides tend to form in the initial stage, whereas Fe-Cr-C solution forms when the degree of reduction is sufficiently high.

关键词： stainless steel dust ternary systems carbothermal reduction reaction kinetics

The effect of Lorentz-like force on collective flows of K+in Au+Au collisions at 1.5 Ge V/nucleon

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Science China(Physics,Mechanics & Astronomy) 2018年第6期61卷 24-29页

作者： YuShan Du YongJia Wang QingFeng Li ling liu School of Science Huzhou University School of Physics science and Technology Shenyang Normal University Institute of Modern Physics Chinese Academy of Sciences

Producing kaon mesons in heavy-ion collisions at beam energies below their threshold energy is an important way to investigate the properties of dense nuclear matter. In this study, based on the newly updated version of the ultrarelativistic quantum molecular dynamics model, we introduce the kaon-nucleon(KN) potential, including both the scalar and vector(also dubbed Lorentz-like)aspects. We revisit the influence of the KN potential on the collective flow of K+mesons produced in Au+Au collisions at Elab= 1.5 Ge V/nucleon and find that the contribution of the newly included Lorentz-like force is very important, particulary for describing the directed flow of K+. Finally, the corresponding Kao S data of both directed and elliptic flows can be simultaneously reproduced well.

关键词： kaon flow heavy-ion collision transport model kaon-nucleon potential

Synthesis of covalently bonded reduced graphene oxide-Fe_(3)O_(4) nanocomposites for efficient electromagnetic wave absorption

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Journal of Materials Science & Technology 2021年第13期72卷 93-103页

作者： Xudong liu Ying Huang ling Ding Xiaoxiao Zhao Panbo liu Tiehu Li MOE Key Laboratory of Material Physics and Chemistry Under Extraordinary Conditions School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072China NPU-NCP Joint International Research Center on Advanced Nanomaterials&Defects Engineering State Key Laboratory of Solidification ProcessingShaanxi Engineering Laboratory for Graphene New Carbon Materials and ApplicationsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

High-performance electromagnetic(EM)wave absorbers,covalently bonded reduced graphene oxideFe_(3)O_(4) nanocomposites(rGO-Fe_(3)O_(4)),are synthesized via hydrothermal reaction,amidation reaction and reduction *** microstructure,surface element composition and morphology of rGO-Fe_(3)O_(4) nanocomposites are characterized and corresponding EM wave absorption properties are analyzed in great *** demonstrates that Fe_(3)O_(4) nanoparticles are successfully covalently grafted onto graphene by amide *** the mass ratio of rGO and Fe_(3)O_(4) is 2:1(sample S2),the absorber exhibits the excellent EM wave absorption performance that the maximum reflection loss(RL)reaches up to-48.6 dB at 14.4 GHz,while the effective absorption bandwidth(RL<-10 dB)is 6.32 GHz(11.68-18.0 GHz)with a matching thickness of 2.1 ***,radar cross section(RCS)simulation calculation is also adopted to evaluate the ability of absorbers to scatter EM waves,which proves again that the absorption performance of absorber S2 is *** outstanding EM wave absorption performance is attributed to the synergistic effect between dielectric and magnetic loss,good attenuation ability and excellent impedance ***,covalent bonds considered to be carrier channels can facilitate electron migration,adjust EM parameters and then enhance EM wave absorption perfo *** work provides a possible method for preparing efficient EM wave absorbers.

关键词： Covalent bond EM wave absorption RCS simulation calculation rGO-Fe_(3)O_(4)nanocomposites

Experiments and kinetic modeling of the sorbitol dehydration to isosorbide catalyzed by sulfuric acid under conditions of non-constant volume

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Chinese Journal of Chemical Engineering 2024年第9期73卷 281-289页

作者： Dechang Cheng Zhihong Ma Ziyang liu Xiaohui liu Tao liu Weizhen Sun ling Zhao State Key Laboratory of Chemical Engineering School of Chemical EngineeringEast China University of Science and TechnologyShanghai 200237China Shanghai Key Laboratory of Functional Materials Chemistry Research Institute of Industrial CatalysisSchool of Chemistry and Molecular EngineeringEast China University of Science and TechnologyShanghai 200237China

Isosorbide is a novel bio-based material derived as a secondary dehydration product of *** work focuses on the kinetics of sulfuric acid-catalyzed dehydration of sorbitol under conditions of nonconstant ***,the effects of stirring rate,catalyst dosage,reaction temperature,and reaction time on the dehydration reaction of sorbitol were *** yield of isosorbide up to 77.13%was obtained after 1.5 h of reaction time under conditions of 2 kPa,1.0%(mass)catalyst dosage,and 413.15 *** on the sorbitol dehydration reaction mechanism and a simplified reaction network,a kinetic model was developed in this work.A good agreement was accomplished between kinetic modeling and experiments between 393.15 and 423.15 *** fitting results indicate that side reactions with higher activation energies are more affected by reaction temperatures,and the main side reaction that influences the selectivity of isosorbide is the oligomerization reaction among the primary dehydration products of *** model fitting of the catalyst amounts effect shows that the effective concentration of sulfuric acid would be reduced with the increase of dosage due to the molecular agglomeration ***,the kinetic experiments and modeling results obtained in this work will be helpful to the design and optimization of the industrial sorbitol dehydration process.

关键词： Isosorbide Sorbitol dehydration Non-constant volume Kinetic modeling

Enantiomer-selective Living Polymerization of rac-Phenyl Isocyanide Using Chiral Palladium Catalyst

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Chinese Journal of Polymer Science 2018年第7期36卷 799-804页

作者： Jian Huang ling Shen Hui Zou Na liu Department of Polymer Science and Engineering School of Chemistry and Chemical Engineering Hefei University of Technology and Anhui Key Laboratory of Advanced Catalytic Materials and Reaction Engineering

We report the polymerization of phenyl isocyanides with the chiral palladium（II） initiating system. The resulting polymers with optically active properties were obtained by polymerization of the racemic isocyanide monomer （rac-1）, and enantiomerically unbalanced polymerization of the monomer was found, providing substantial evidence for the enantiomer-selective polymerization of rac- 1 mediated through chiral catalyst. A comparison between the enantiomerically pure monomers, 4-isocyanobenzoyl-L-alanine decyl ester （1 s） and 4-isocyanobenzoyl-D-alanine decyl ester （1 r）, revealed a drastic discrepancy in the reactivity ratio of their homopolymerizations. It turned out that the monomer reactivity ratio of ls was higher than that of lr with chiral ligands. The results clearly demonstrated the inclination for incorporation of the ls enantiomer during the polymerization process and thus resulted in the enantiomer-selective polymerization in this system. The effects of the catalyst chirality on the optically active properties of polymerization were investigated, and it was concluded that the formation of higher-ordered conformation with a handed helicity might be attributed to the chiral induction of chiral palladium（II） catalyst. Moreover, the polymers obtained through the enantiomer-selective polymerization of the enantiomerically pure monomer were with a significant improvement of the optical activity if the chirality of the monomer and the catalyst matched with each other.

关键词： Enantiomer-selective polymerization Kinetic resolution Chiral sulfinamide bisphosphine Polyisocyanides Living polymerization

Effects of iron precursors on the structure and catalytic performance of iron molybdate prepared by mechanochemical route for methanol to formaldehyde

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Chinese Journal of Chemical Engineering 2020年第6期28卷 1603-1611页

作者： lingtao Kong Shengtao Xu Xue liu Chaofan liu Dandan Zhang ling Zhao Key Laboratory of Coal Clean Conversion&Chemical Engineering Process College of Chemistry and Chemical EngineeringXinjiang UniversityUrumqi 830046China Key Laboratory of Oil and Gas Fine Chemicals of Education College of Chemistry and Chemical EngineeringXinjiang UniversityUrumqi 830046China

Mechanochemical synthesis has been applied for many novel material preparations and gained more and more attention due to green and high-efficiency recently. In order to explore the influences of iron precursors on structure and performance of iron molybdate catalyst prepared by mechanochemical route, three typical and cheap iron precursors have been used in preparation of iron molybdate catalyst. Many characterization methods have been employed to obtain the physical and chemical properties of iron molybdate catalyst. Results indicate that iron precursors have the significant impact on the phase composition, crystal morphology and catalytic performance in the conversion of methanol to formaldehyde. It is hard to regulate the phase composition by changing Mo/Fe mole ratios for Fe2(SO4)3 as iron precursor. In addition, as for Fe2(SO4)3, the formaldehyde yield is lower than that from iron molybdate catalyst prepared with Fe(NO3)3·9H2O due to the reduction in Fe2(MoO4)3 phase as active phase. Based on mechanochemical and coprecipitation method, the solvent water could be a key factor for the formation of MoO3 and Fe2(MoO4) for FeCl3·6H2O and Fe2(SO4)3 as precursors. Iron molybdate catalyst prepared with Fe(NO3)3·9H2O by mechanochemical route, shows the best methanol conversion and formaldehyde yield in this reaction.

关键词： Iron precursors Mechanochemical route Iron molybdate catalyst Methanol oxidation