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IEEE/CAA Journal of Automatica Sinica 2020年第3期7卷 892-900页

作者： Tong Yang Ning Sun He Chen Yongchun Fang Institute of Robotics and Automatic Information Systems(IRAIS) College of Artificial IntelligenceTianjin 300350China Tianjin Key Laboratory of Intelligent Robotics(tjKLIR) Nankai UniversityTianjin 300350China IEEE School of Artificial Intelligence Hebei University of TechnologyTianjin 300401China

Offshore cranes are widely applied to transfer largescale cargoes and it is challenging to develop effective control for them with sea wave disturbances. However, most existing controllers can only yield ultimate uniform boundedness or asymptotical stability results for the system's equilibrium point, and the state variables' convergence time cannot be theoretically guaranteed. To address these problems, a nonlinear sliding mode-based controller is suggested to accurately drive the boom/rope to their desired positions. Simultaneously, payload swing can be eliminated rapidly with sea waves. As we know, this paper firstly presents a controller by introducing error-related bounded functions into a sliding surface, which can realize boom/rope positioning within a finite time, and both controller design and analysis based on the nonlinear dynamics are implemented without any linearization manipulations. Moreover, the stability analysis is theoretically ensured with the Lyapunov method. Finally, we employ some experiments to validate the effectiveness of the proposed controller.

关键词： Boom/rope positioning offshore cranes swing elimination underactuated systems

A route for the study on mass transfer enhancement by adding particles in liquid phase

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Chinese Journal of Chemical Engineering 2022年第8期35卷 158-165页

作者： Xing Su ning Qiao Bao-Chang sun College of Chemical and Material Engineering Quzhou UniversityQuzhou 324000China State Key Laboratory of Organic-Inorganic Composites Beijing University of Chemical TechnologyBeijing 100029China Research Center of the Ministry of Education for High Gravity Engineering and Technology Beijing University of Chemical TechnologyBeijing 100029China

This work presents a route for the study on the absorption performance of gas into liquid under the condition of adding particles in a stirred constant temperature reactor.Two evaluated systems,hydrogen–water and hydrogen–methanol,with the addition of activated carbon particles(ACP)were carried out,respectively.The results showed that the addition of ACP into the water can enhance the mass transfer between hydrogen and water,the enhancement factor increases rapidly with the increase of the ACP content,and then tends to be unchanged.However,for the hydrogen–methanol system,ACP has little effect on the mass transfer performance.In addition,a gas–liquid mass transfer model considering the effect of solid particle enhancement was established based on the shuttle effect and two-film model.Results indicated that the predicted value agreed well with the experimental value in both hydrogen–methanol–ACP and hydrogen–water–ACP systems.

关键词： Mass transfer Hydrogen Water Methanol Activated carbon

Base-Promoted Formylation and N-Difluoromethylation of Azaindoles with Ethyl Bromodifluoroacetate as a Carbon Source

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Chinese Journal of Chemistry 2021年第6期39卷 1477-1482页

作者： Yang Li Ning Sun Cai-Lin Zhang Meng Hao Xi'an Key Laboratory of Textile Chemical Engineering Auxiliaries School of Environmental and Chemical EngineeringXi'an Polytechnic UniversityXi'anShaanxi 710048China

We reported for the first time that ethyl bromodifluoroacetate directly reacts with azaindole without transition metal catalysis to produce a difluoromethyl protected 5-aldehyde group product in one step.It is worth mentioning that the reacted aldehyde group is only formed at the 5 position.In addition,this method has good substrate applicability and functional group tolerance.Finally,we also carried out some mechanism auxiliary experiments,which confirmed that the aldehyde-based carbon comes from ethyl bromodifluoroacetate.

关键词： Azaindoles C1 building blocks Difluoromethylene Hydrolysis Synthetic methods

The recent progress of pitch-based carbon anodes in sodium-ion batteries

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Journal of Energy Chemistry 2021年第4期30卷 34-47页

作者： Mingchi Jiang Ning Sun Razium Ali Soomro Bin Xu State Key Laboratory of Organic-Inorganic Composites Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China Beijing Advanced Innovation Centre for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China

Sodium-ion batteries(SIBs)have attracted significant attentions as promising alternatives to lithium-ion batteries for large-scale energy storage applications.Here carbon materials are considered as the most competitive anodes for SIBs based on their low-cost,abundant availability and excellent structural stability.Pitch,with high carbon content and low cost,is an ideal raw precursor to prepare carbon materials for large-scale applications.Nevertheless,the microstructures of pitch-based carbon are highly ordered with smaller interlayer distances,which are unfavorable for Na ion storage.Many efforts have been made to improve the sodium storage performance of pitch-based carbon materials.This review summarizes the recent progress about the application of pitch-based carbons for SIBs anodes in the context of carbon’s morphology and structure regulation strategies,including morphology adjustment,heteroatoms doping,fabricating heterostructures,and the increase of the degree of disorder.Besides,the advantages,present challenges,and possible solutions to current issues in pitch-based carbon anode are discussed,with the highlight of future research directions.This review will provide a deep insight into the development of low-cost and high-performance pitch-based carbon anode for SIBs.

关键词： Pitch Carbon anode Sodium-ion batteries Structure regulation Electrochemical performance

Mechanism studies of the activation of DNA methyltransferase DNMT1 triggered by histone H3 ubiquitination,revealed by multi-scale molecular dynamics simulations

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Science China(Life Sciences) 2023年第2期66卷 313-323页

作者： Jixue sun Fei Liu Longxiao Yuan ning-ning Pang Bing Zhu Na Yang State Key Laboratory of Medicinal Chemical Biology College of Pharmacy and Key Laboratory of Medical Data Analysis and Statistical Research of TianjinNankai UniversityTianjin 300353China National Laboratory of Biomacromolecules CAS Center for Excellence in BiomacromoleculesInstitute of BiophysicsChinese Academy of SciencesBeijing 100101China

DNMT1 is a DNA methyltransferase that catalyzes and maintains methylation in CpG dinucleotides.It blocks the entrance of DNA into the catalytic pocket via the replication foci targeting sequence(RFTS)domain.Recent studies have shown that an H3-tail-conjugated two-mono-ubiquitin mark(H3Ub2)activates DNMT1 by binding to the RFTS domain.However,the activation mechanism of DNMT1 remains unclear.In this work,we combine various sampling methods of extensive simulations,including conventional molecular dynamics,Gaussian-accelerated molecular dynamics,and coarse-grained molecular dynamics,to elucidate the activation mechanism of DNMT1.Geometric and energy analyses show that binding of H3Ub2 to the RFTS domain of DNMT1 results in the bending of theα4-helix in the RFTS domain at approximately 30°–35°,and the RFTS domain rotates~20°anti-clockwise and moves~3?away from the target recognition domain(TRD).The hydrogen-bonding network at the RFTSTRD interface is significantly disrupted,implying that the RFTS domain is dissociated from the catalytic core,which contributes to activating the auto-inhibited conformation of DNMT1.These results provide structural and dynamic evidence for the role of H3Ub2 in regulating the catalytic activity of DNMT1.

关键词： DNA methyltransferase conformational change molecular dynamics simulation activation molecular mechanism

Air-coupled piezoelectric micromachined ultrasonic transducers for surface stain detection and imaging

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Nanotechnology and Precision Engineering 2022年第1期5卷 35-42页

作者： Sheng sun Jianyuan Wang Yuan ning Menglun Zhang State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China

This paper proposes an air-coupled piezoelectric micromachined ultrasonic transducer(PMUT)for detection and imaging of surface stains.A 508 kHz PMUT array is designed,fabricated,and characterized in terms of its electrical and acoustic properties,and it is used in a pulse echo validation test.Imaging of stains on metal blocks is successfully demonstrated.Compared with existing optical methods for stain detection,the proposed approach can work in a dark environment without color requirements.This work provides a new and promising route for the development of miniaturized stain detection systems.

关键词： PMUT Air-coupled imaging Stain detection Time of flight

Changes of DOM and its correlation with internal nutrient release during cyanobacterial growth and decline in Lake Chaohu, China

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Journal of Environmental Sciences 2023年第2期124卷 769-781页

作者： Yan Bao Tao Huang Chengwu ning Tingting sun Pengliang Tao Jie Wang Qingye sun School of Resources and Environmental Engineering Anhui UniversityHefei 230601China Anhui Province Key Laboratory of Wetland Ecosystem Protection and Restoration Anhui UniversityHefei 230601China

The seasonal changes in dissolved organic matter(DOM),and its correlation with the release of internal nutrients during the annual cycle of cyanobacteria in the eutrophic Lake Chaohu,China,were investigated from four sampling periods between November 2020 and July 2021.The DOM fluorescence components were identified as protein-like C1,microbial humic-like C2,and terrestrial humic-like C3.The highest total fluorescence intensity(FT)of DOM in sediments during the incubation stage is due to the decomposition and degradation of cyanobacteria remains.The lowest humification of DOM and the highest proportion of C1 in waters during the initial cyanobacterial growth indicate that fresh algae are the main source.The highest molecular weight of DOM and FT of the C2 in sediments during cyanobacterial outbreaks indicate the concurrent deposition of undegraded cyanobacterial remains and microbial degradation.The components of DOM are affected mainly by the dissolved total phosphorus in waters,while the temperature drives the annual cycle of cyanobacteria.The decreasing C1 in sediments and increasing nutrients in waters from the cyanobacterial incubation to outbreak indicate that mineralization of algal organic matter contributes importantly to the release of internal nutrients,with the strongest release of phosphorus observed during the early growth of cyanobacteria.The humic-like C2 and C3 components could also affect the dynamics of internal phosphorus through the formation of organic colloids and organic–inorganic ligands.The results show that the degradation of DOM leads to nutrients release and thus supports the continuous growth of cyanobacteria in eutrophic Lake Chaohu.

关键词： Eutrophication Shallow lake Sediment-water interface Algal blooms Fluorescence components PARAFAC

BER Performance Analysis of OTFS Systems with Power Allocation

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China Communications 2023年第1期20卷 24-35页

作者： Zhenduo Wang Zhipeng Liu Zhiguo sun Xiaoyan ning College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China

Orthogonal time frequency space(OTFS),as a novel 2-D modulation technique,has been proposed to achieve better BER performances over delayDoppler channels.In this paper,we propose two different power allocation(PA)algorithms in OTFS systems with zero forcing(ZF)or minimum mean square error(MMSE)equalization,where general formulas with PA are derived in advance under the condition of minimum BER(MBER)criterion.On one hand,a suboptimal MBER power allocation method is put forward to achieve better BER performances,and then analytical BER expressions are derived with proposed PA strategy.Considering the case of MMSE equalization,a combined subsymbol allocation(SA)and PA strategy is raised,where some subsymbols may be abandoned due to worse channel conditions,and then it is proven effectively to improve BER performances through theoretical and simulation results.Furthermore,BER performances with proposed joint SA and PA strategy are also investigated in delay-Doppler channels,where an improved message passing(MP)receiver based on equivalent channel matrix with PA is given.

关键词： OTFS PA ZF MMSE BER analysis

Hierarchical Cooperative Control of Connected Vehicles:From Heterogeneous Parameters to Heterogeneous Structures

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IEEE/CAA Journal of Automatica Sinica 2022年第9期9卷 1590-1602页

作者： Manjiang Hu Lingkun Bu Yougang Bian Hongmao Qin Ning Sun Dongpu Cao Zhihua Zhong the State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China Wuxi Intelligent Control Research Institute Hunan UniversityWuxi 214115China the School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China

As one of the typical applications of connected vehicles(CVs),the vehicle platoon control technique has been proven to have the advantages of reducing emissions,improving traffic throughout and driving safety.In this paper,a unified hierarchical framework is designed for cooperative control of CVs with both heterogeneous model parameters and structures.By separating neighboring information interaction from local dynamics control,the proposed framework is designed to contain an upper-level observing layer and a lower-level tracking control layer,which helps address the heterogeneity in vehicle parameters and structures.Within the proposed framework,an observer is designed for following vehicles to observe the leading vehicle's states using neighboring communication,while a tracking controller is designed to track the observed leading vehicle using local feedback control.Closed-loop stability in the absence and presence of communication time delay is analyzed,and the observer is further extended to a finite time convergent one to address string stability under general communication topology.Numerical simulation and field experiment verify the effectiveness of the proposed method.

关键词： Communication delay connected vehicle(CV) heterogeneity string stability vehicle platoon

3D landscape reorganization in response to feeding preferences adaptation in the youngest split Gymnocypris fish

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Journal of Genetics and Genomics 2023年第4期50卷 289-292页

作者： Ning Sun Cheng Wang Wenqi Lv Xiaoni Gan Liandong Yang Shunping He Chengchi Fang State Key Laboratory of Freshwater Ecology and Biotechnology Institute of HydrobiologyChinese Academy of SciencesWuhanHubei 430072China University of Chinese Academy of Sciences Beijing 100049China Center for Excellence in Animal Evolution and Genetics Chinese Academy of SciencesKunmingYunnan 650223China

Divergence in feeding preference is one of the main mechanisms that lead to the emergence of new species.However,little is known about the underlying genetic mechanism of feeding preference adaptation,especially in the three-dimensional(3D)chromatin organization regulation.Gymnocypris eckloni scoliostomus(GS)and G.eckloni eckloni(GE)are two sister species of G.eckloni(Cyprinidae:Schizothoracinae:Gymnocypris).

关键词： species fish Cyprinidae