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Safe Motion Planning and Control Framework for Automated Vehicles with Zonotopic TRMPC

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Engineering 2024年第2期33卷 146-159页

作者： Hao zheng Yinong li ling zheng Ehsan Hashemi State Key Laboratory of Mechanical Transmissions College of Mechanical and Vehicle EngineeringChongqing UniversityChongqing 400044China Department of Mechanical Engineering University of AlbertaEdmontonAB T6G 2H5Canada

Model mismatches can cause multi-dimensional uncertainties for the receding horizon control strategies of automated vehicles(AVs).The uncertainties may lead to potentially hazardous behaviors when the AV tracks ideal trajectories that are individually optimized by the AV's planning layer.To address this issue,this study proposes a safe motion planning and control(SMPAC)framework for AVs.For the control layer,a dynamic model including multi-dimensional uncertainties is established.A zonotopic tube-based robust model predictive control scheme is proposed to constrain the uncertain system in a bounded minimum robust positive invariant set.A flexible tube with varying cross-sections is constructed to reduce the controller conservatism.For the planning layer,a concept of safety sets,representing the geometric boundaries of the ego vehicle and obstacles under uncertainties,is proposed.The safety sets provide the basis for the subsequent evaluation and ranking of the generated trajectories.An efficient collision avoidance algorithm decides the desired trajectory through the intersection detection of the safety sets between the ego vehicle and obstacles.A numerical simulation and hardware-in-the-loop experiment validate the effectiveness and real-time performance of the SMPAC.The result of two driving scenarios indicates that the SMPAC can guarantee the safety of automated driving under multi-dimensional uncertainties.

关键词： Automated vehicles Automated driving Motion planning Motion control Tube MPC Zonotope

Bleeding control during complex laparoscopic surgeries of the spleen:current status and challenges

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Chinese Medical Journal 2022年第24期135卷 2938-2940页

作者： Nan You Jing li Lu zheng Department of Hepatobiliary Surgery The Second Affiliated HospitalThird Military Medical University(Army Medical University)Chongqing 400037China

Severe intra-operative bleeding has limited the application of complex laparoscopic splenectomy(LS),including laparoscopic total splenectomy(LTS)and laparoscopic partial splenectomy(LPS).Therefore,reducing bleeding ri... 详细信息

关键词： laparoscopic spleen bleeding

lncRNA TUG1 regulates Smac/DIABLO expression by competitively inhibiting miR-29b and modulates the apoptosis of lens epithelial cells in age-related cataracts

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中华医学杂志（英文版） 2023年第19期136卷 2340-2350页

作者： Miaomiao Sun Ke li Xiao li Huajun Wang li li Guangying zheng China Department of Ophthalmology Luohe City Central Hospital Luohe Henan 462000 China450000 China 450000

Background: As one of the early discovered long non-coding RNAs (lncRNA), taurine upregulation gene 1 ( TUG1 ) has been widely expressed in a variety of tumors. Moreover, it promotes cell proliferation, differentiation, apoptosis, and migration. However, our understanding of its importance in the pathogenesis of cataracts remains limited. This study aimed to explore the mechanism by which lncRNA TUG1 mediates lens epithelial cell apoptosis in age-related cataracts (ARC) by regulating the microRNAs (miR-29b)/second mitochondria-derived activator of caspases axis, and to identify more non-surgical strategies for cataract treatment. Methods: The messenger RNA expression levels of TUG1 , miR-29b, and Smac were detected using quantitative real-time polymerase chain reaction in vivo and in vitro . The expression of the Smac protein was analyzed by Western blotting and immunofluorescence. Flow cytometry and cell counting kit-8 assays were used to detect the cell apoptosis and proliferation rates, respectively. The targeted regulatory relationship between lncRNA TUG1 , miR-29b, and Smac was verified by viral vector construction, co-transfection, nuclear and cytoplasmic separation, luciferase reporter assays, and RNA immunoprecipitation. Results: TUG1 and Smac were expressed at high levels in ARC and HLE-B3 cells treated with 200 μmol/L H 2 O 2 , whereas miR-29b expression was decreased. In vitro cell experiments confirmed that down-regulation of TUG1 could inhibit the apoptosis of lens epithelial cells. Mechanistically, Smac expression was negatively regulated by miR-29b. TUG1 competitively inhibited miR-29b expression and caused greater release of Smac. In addition, miR-29b partially reversed the effects of TUG1 on human lens epithelial cell line cells. Conclusions: lncRNA TUG1 increases Smac expression and promotes apoptosis of lens epithelial cells in ARC by competitively inhibiting miR-29b. This mechanism is the cytological basis for ARC formation. Based on these results, the lncRNA TUG1/miR29b/Smac

关键词： Apoptosis Cataract lncRNA TUG1 MicroRNA-29 Smac

Application of MMC with Embedded Energy Storage for Overvoltage Suppression and Fault Ride-through Improvement in Series LCCMMC Hybrid HVDC System

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Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 1001-1013页

作者： Xiaodong li zheng Xu Zheren Zhang Department of Electrical Engineering Zhejiang UniversityHangzhou 310027China IEEE

The series line-commutated converter(LCC)and modular multilevel converter(MMC)hybrid high-voltage direct current(HVDC)system provides a more economical and flexible alternative for ultra-HVDC(UHVDC)transmission,which is the so-called Baihetan-Jiangsu HVDC(BJ-HVDC)project of China.In one LCC and two MMCs(1+2)operation mode,the sub-module(SM)capacitors suffer the most rigorous overvoltage induced by three-phase-to-ground fault at grid-side MMC and valve-side single-phase-to-ground fault in internal MMC.In order to suppress such huge overvoltage,this paper demonstrates a novel alternative by employing the MMC-based embedded battery energy storage system(MMC-BESS).Firstly,the inducements of SM overvoltage are analyzed.Then,coordinated with MMC-BESS,new fault ride-through(FRT)strategies are proposed to suppress the overvoltage and improve the FRT capability.Finally,several simulation scenarios are carried out on PSCAD/EMTDC.The overvoltage suppression is verified against auxiliary device used in the BJ-HVDC project in a monopolar BJ-HVDC system.Further,the proposed FRT strategies are validated in the southern Jiangsu power grid of China based on the planning data in the summer of 2025.Simulation results show that the MMC-BESS and proposed FRT strategies could effectively suppress the overvoltage and improve the FRT capability.

关键词： line-commutated converter(LCC) modular multilevel converter(MMC) MMC-based embedded battery energy storage system(MMC-BESS) fault ride-through(FRT)capability overvoltage suppression

Synthesis and in vitro evaluation of Ca-P coating on biodegradable Zn alloys

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Journal of Materials Science & Technology 2023年第10期141卷 124-134页

作者： Huafang li Yixing zheng Xiaojing Ji School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China

The burst release of Zn 2+from the naked pure Zn and Zn-based alloys could induce local and sys-temic toxicity,which limits their clinical applications as biodegradable implants.In order to inhibit the explosive release of zinc ions,a protective Ca-P coating was synthesized on biodegradable Zn al-loy.The microstructure,corrosion resistance,antibacterial activity,and biosafety of the Ca-P coating are systematically investigated.Electrochemical tests revealed that Ca-P protective layer has enhanced the anti-corrosion behavior of Zn alloy.Furthermore,Ca-P protective layer showed good biocompatibility,as demonstrated by significantly increased cell viability,good attachment,and spreading at a higher cell density.Besides,the Ca-P coating could also retain the antibacterial ability and inhibit the bacterial ad-hesion.The Ca-P protective layer synthesized on biodegradable Zn alloy can be considered and applied in future biomedical applications.

关键词： Zinc alloy Biodegradable metals Ca-P coating Corrosion behavior Biocompatibility

Dynamic modelling and simulation of a post-combustion CO_(2) capture process for coal-fired power plants

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Frontiers of Chemical Science and Engineering 2022年第2期16卷 198-209页

作者： Jianlin li Ti Wang Pei liu zheng li State Key Lab of Power Systems International Joint Laboratory on Low Carbon Clean Energy InnovationDepartment of Energy and Power EngineeringTsinghua UniversityBeijing 100084China

Solvent-based post-combustion capture technologies have great potential for CO_(2)mitigation in traditional coal-fired power plants.Modelling and simulation provide a low-cost opportunity to evaluate performances and guide flexible operation.Composed by a series of partial differential equations,first-principle post-combustion capture models are computationally expensive,which limits their use in real time process simulation and control.In this study,we propose a first-principle approach to develop the basic structure of a reduced-order model and then the dominant factor is used to fit properties and simplify the chemical and physical process,based on which a universal and hybrid post-combustion capture model is established.Model output at steady state and trend at dynamic state are validated using experimental data obtained from the literature.Then,impacts of liquidto-gas ratio,reboiler power,desorber pressure,tower height and their combination on the absorption and desorption effects are analyzed.Results indicate that tower height should be designed in conjunction with the flue gas flow,and the gas-liquid ratio can be optimized to reduce the reboiler power under a certain capture target.

关键词： CO_(2)capture post-combustion capture simulation dominant factor

Smart systems engineering contributing to an intelligent carbon-neutral future: opportunities, challenges, and prospects

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Frontiers of Chemical Science and Engineering 2022年第6期16卷 1023-1029页

作者： Xiaonan Wang Jie li Yingzhe zheng Jiali li Department of Chemical Engineering Tsinghua UniversityBeijing 100084China Department of Chemical&Biomolecular Engineering Faculty of EngineeringNational University of SingaporeSingapore 117585Singapore

This communication paper provides an overview of multi-scale smart systems engineering(SSE)approaches and their applications in crucial domains including materials discovery,intelligent manufacturing,and environmental management.A major focus of this interdisciplinary field is on the design,operation and management of multi-scale systems with enhanced economic and environmental performance.The emergence of big data analytics,internet of things,machine learning,and general artificial intelligence could revolutionize next-generation research,industry and society.A detailed discussion is provided herein on opportunities,challenges,and future directions of SSE in response to the pressing carbon-neutrality targets.

关键词： machine learning modeling material industrial applications environment

Analysis of genetic diversity and prediction of Larix species distribution in the Qinghai–Tibet Plateau,China

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Journal of Forestry Research 2023年第3期34卷 705-715页

作者： Qiqiang Guo Huie li Weilie zheng Jinwen Pan Jie Lu Jiangrong li Yu zheng Institute for Forest Resources&Environment of Guizhou Key Laboratory of Forest Cultivation in Plateau Mountain of Guizhou ProvinceGuizhou UniversityGuiyang 550025People’s Republic of China College of Forestry Guizhou UniversityGuiyang 550025People’s Republic of China College of Agriculture Guizhou UniversityGuiyang 550025People’s Republic of China Institute of Tibet Plateau Ecology Tibet Agriculture and Animal Husbandry UniversityNyingchi Tibet 860000People’s Republic of China Key Laboratory of Forest Ecology in Tibet Plateau(Tibet Agriculture and Animal Husbandry University) Ministry of EducationNyingchi Tibet 860000People’s Republic of China Plant Research Center Chengdu Botanical GardenChengdu 610083People’s Republic of China

Larix resources in the Qinghai-Tibet Plateau have important ecological and economic values.However,the lack of genetic diversity background and related research hinders the development of conservation strategies.In this study,genetic diversity and distribution of fi ve Larix species were investigated.Using 19 polymorphic microsatellite markers to study 272 representative individuals from 13 populations,the results show low genetic diversity at the population level,with variation explained mainly by diff erentiation among populations.The Larix populations were classifi ed into two clades,one formed by eight populations,including three of the species in this study,L.kongboensis,L.speciosa,and L.potaninii var.australis.The other clade consists of fi ve populations,including the other two species in this study,L.griffi thii and L.himalaica.Genetic distance of the species was aff ected by geographical isolation and genetic diversity was mainly aff ected by altitude.The area suitable for Larix spp.decreased during the Last Glacial Maximum compared to the current distribution according to the niche model,but should increase in future climate scenarios(2050s),expanding westward along the Himalayas.These results provide an important scientifi c basis for the development of conservation strategies and further the sustainable utilization of Larix resources in the Qinghai-Tibet Plateau.

关键词： Larix spp. Genetic diversity Phylogenetic relationship Genetic structure Ecological niche modeling Qinghai-Tibet Plateau

Catalytic asymmetric silicon-carbon bond-forming transformations based on Si–H functionalization

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Science China Chemistry 2023年第6期66卷 1654-1687页

作者： li li Wei-Sheng Huang zheng Xu li-Wen Xu China Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education Key Laboratory of Organosilicon Material Technology of Zhejiang ProvinceCollege of MaterialChemistry and Chemical EngineeringHangzhou Normal UniversityHangzhou 311121China State Key Laboratory for Oxo Synthesis and Selective Oxidation Suzhou Research InstituteLanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China

In view of the exciting advancement on silicon–carbon bond-forming transformations achieved in the past decade,this review intends to show a unified illustration of the recent findings on enantioselective Si–H bond functionalization aided by asymmetric catalysis.Accordingly,this review describes the enantioselective silicon–carbon bond-forming Si–H bond functionalization,focusing on the reactivity and stereoselectivity in catalytic asymmetric hydrosilylation,carbene Si–H insertion,C–H silylation,and Si–C bond-forming cross-coupling reactions that were achieved with high enantioselectivity in the presence of transitionmetal catalyst systems.This review highlights recent and representative examples of the enantioselective Si–H bond functionalization,discusses the origins of silicon-involving stereoselectivities,and evaluates the substrate scopes and limitations in these catalytic asymmetric Si–H bond functionalization reactions due to the special reactivity of different hydrosilanes.

关键词： Si-H functionalization hydrosilylation C-H silylation carbene Si-H insertion asymmetric catalysis