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An interlaminar damage shell model for typical composite structures

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Chinese Journal of Aeronautics 2024年第1期37卷 118-137页

作者： Jie ZHOU zhen wu zhengliang liu Xiaohui REN School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China National Key Laboratory of Strength and Structural Integrity Xi’an 710065China School of Mechanical Engineering Xi’an Aeronautical UniversityXi’an 710065China

Using the plate/shell elements in commercial software,accurate analysis of interlaminar initial damage in typical composite structures is still a challenging issue.To propose an accurate and efficient model for analysis of interlaminar initial damage,the following work is carried out:(A)A higher-order theory is firstly proposed by introducing the local Legendre polynomials,and then a novel shell element containing initial damage prediction is developed,which can directly predict transverse shear stresses without any postprocessing methods.Unknown variables at each node are independent of number of layers,so the proposed model is more efficient than the 3D-FEM.(B)Compression experiment is carried out to verify the capability of the proposed model.The results obtained from the proposed model are in good agreement with experimental data.(C)Several examples have been analyzed to further assess the capability of the proposed model by comparing to the 3D-FEM results.Moreover,accuracy and efficiency have been evaluated in different damage criterion by comparing with the selected models.The numerical results show that the proposed model can well predict the initial interlaminar damage as well as other damage.Finally,the model is implemented with UEL subroutine,so that the present approach can be readily utilized to analyze the initial damage in typical composite structures.

关键词： Compression experiment Finite element method Initial damage Interlaminar stress Plate/shell element

Data and Model Driven Task Offloading Strategy in the Dynamic Mobile Edge Computing System

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Journal of Systems Science & Complexity 2024年第1期37卷 351-368页

作者： DONG Hairong wu Wei SONG Haifeng liu zhen ZHANG Zixuan School of Electronic and Information Engineering Beijing Jiaotong UniversityBeijing 100044China School of Electronic and Information Engineering BeiHang UniversityBeijing 100191China CRSC Research&Design Institute Group Co. Ltd.Beijing 100070China

Mobile Edge Computing(MEC)provides communication and computational capabilities for the industrial Internet,meeting the demands of latency-sensitive tasks.Nevertheless,traditional model-driven task offloading strategies face challenges in adapting to situations with unknown network communication status and computational capabilities.This limitation becomes notably significant in complex industrial networks of high-speed railway.Motivated by these considerations,a data and model-driven task offloading problem is proposed in this paper.A redundant communication network is designed to adapt to anomalous channel states when tasks are offloaded to edge servers.The link switching mechanism is executed by the train according to the attributes of the completed task.The task offloading optimization problem is formulated by introducing data-driven prediction of communication states into the traditional model.Furthermore,the optimal strategy is achieved by employing the informer-based prediction algorithm and the quantum particle swarm optimization method,which effectively tackle real-time optimization problems due to their low time complexity.The simulations illustrate that the data and model-driven task offloading strategy can predict the communication state in advance,thus reducing the cost of the system and improving its robustness.

关键词： Data driven model informer mobile edge computing quantum particle swarm optimization task offloading.

Decentralized Primary Frequency Regulation for Hybrid Multi-terminal Direct Current Power Systems Considering Multi-source Enhancement

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 958-970页

作者： Jialiang wu zhen Wang Ruixu liu Yu Shan Chenxuan Wang the College of Electrical Engineering Zhejiang University IEEE the Economic Research Institute of State Grid Zhejiang Electric Power Co. Ltd.

Hybrid multi-terminal direct current(MTDC) transmission technology has been a research focus, and primary frequency regulation(FR) improvement in the receiving-end system is one of the problems to be solved. This paper presents a decentralized primary FR scheme for hybrid MTDC power systems considering multi-source enhancement to help suppress frequency disturbance in the receiving-end systems. All the converters only need local frequency or DC voltage signal input to respond to system disturbance without communication or a control center, i. e., a decentralized control scheme. The proposed scheme can activate appropriate power sources to assist in FR in various system disturbance severities with fine-designed thresholds, ensuring sufficient utilization of each power source. To better balance FR performance and FR resource participation, an evaluation index is proposed and the parameter optimization problem is further conducted. Finally, the validity of the proposed scheme is verified by simulations in MATLAB/Simulink.

关键词： Frequency control HVDC transmission Voltage control Hybrid power systems Frequency conversion Voltage measurement Power system stability

Towards overcoming obstacles of type Ⅱ photodynamic therapy:Endogenous production of light,photosensitizer,and oxygen

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Acta Pharmaceutica Sinica B 2024年第3期14卷 1111-1131页

作者： Lin Yu zhen liu Wei Xu Kai Jin Jinliang liu Xiaohui Zhu Yong Zhang Yihan wu Department of Chemical and Environmental Engineering Shanghai UniversityShanghai 200433China School of Medicine Shanghai UniversityShanghai 200433China Department of Biomedical Engineering City University of Hong KongHong KongChina

Conventional photodynamic therapy(PDT)approaches face challenges including limited light penetration,low uptake of photosensitizers by tumors,and lack of oxygen in tumor microenvironments.One promising solution is to internally generate light,photosensitizers,and oxygen.This can be accomplished through endogenous production,such as using bioluminescence as an endogenous light source,synthesizing genetically encodable photosensitizers in situ,and modifying cells genetically to express catalase enzymes.Furthermore,these strategies have been reinforced by the recent rapid advancements in synthetic biology.In this review,we summarize and discuss the approaches to overcome PDT obstacles by means of endogenous production of excitation light,photosensitizers,and oxygen.We envision that as synthetic biology advances,genetically engineered cells could act as precise and targeted“living factories”to produce PDT components,leading to enhanced performance of PDT.

关键词： Photodynamic therapy Cancer Biogenesis Biosynthesis Engineered bacteria Phototherapy Photosensitizers Catalase

Super Resolution Fluorescence Microscopy for Cilia Investigation and Ciliopathy Diagnosis

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激光与光电子学进展 2024年

作者： zhen liu Yang wu Division of Life Science The Hong Kong University of Science and Technology

The last two decades have witnessed the invention and development of superresolution microscopy(SRM), which breaks the diffraction limit of light and pushes the resolution of fluorescence microscopy to several nanometers. SRM is now widely applied in biological studies such as resolving subdiffraction structures, molecular mapping, single molecule tracking, probing protein-protein interactions, and observing organelle dynamics. However, its direct application in translational medicine such as disease diagnosis is still preliminary. Despite their small size, cilia play a crucial role as organelles in cell signaling and motility, and defects in cilia lead to ciliopathy. Like other miniature organelles and macromolecular complexes, cilia are ideal for superresolution imaging. In this review, we will 1) introduce cilia and ciliopathy, 2) show how SRM extends our knowledge of cilia, and 3) focus on how SRM improves the diagnosis of motile ciliopathies.

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Patient-derived induced pluripotent stem cells with a MERTK mutation exhibit cell junction abnormalities and aberrant cellular differentiation potential

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World Journal of Stem Cells 2024年第5期16卷 512-524页

作者： Hang Zhang Ling-Zi wu zhen-Yu liu Zi-Bing Jin Beijing Institute of Ophthalmology Beijing Tongren Eye CenterBeijing Tongren HospitalCapital Medical UniversityBeijing 100730China

BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease mechanisms.However,iPSCs carrying specific mutations may limit their clinical applications due to certain inherent characteristics.AIM To investigate the impact of MERTK mutations on hiPSCs and determine whether hiPSC-derived extracellular vesicles(EVs)influence anomalous cell junction and differentiation potential.METHODS We employed a non-integrating reprogramming technique to generate peripheral blood-derived hiPSCs with and hiPSCs without a MERTK mutation.Chromo-somal karyotype analysis,flow cytometry,and immunofluorescent staining were utilized for hiPSC identification.Transcriptomics and proteomics were employed to elucidate the expression patterns associated with cell junction abnormalities and cellular differentiation potential.Additionally,EVs were isolated from the supernatant,and their RNA and protein cargos were examined to investigate the involvement of hiPSC-derived EVs in stem cell junction and differentiation.RESULTS The generated hiPSCs,both with and without a MERTK mutation,exhibited normal karyotype and expressed pluripotency markers;however,hiPSCs with a MERTK mutation demonstrated anomalous adhesion capability and differentiation potential,as confirmed by transcriptomic and proteomic profiling.Furthermore,hiPSC-derived EVs were involved in various biological processes,including cell junction and differentiation.CONCLUSION HiPSCs with a MERTK mutation displayed altered junction characteristics and aberrant differentiation potential.Furthermore,hiPSC-derived EVs played a regulatory role in various biological processes,including cell junction and differentiation.

关键词： Cell junction Cellular differentiation Extracellular vesicle Human induced pluripotent stem cells Transcriptomics Proteomics

Track-Pattern-Based Characteristics of Extratropical Transitioning Tropical Cyclones in the Western North Pacific

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Advances in Atmospheric Sciences 2024年第6期41卷 1251-1263页

作者： Hong HUANG Dan wu Yuan WANG zhen WANG Yu liu College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China No.31631 Army of PLA Huizhou 516000China School of Atmospheric Sciences and Key Laboratory of Mesoscale Severe Weather/Ministry of Education Nanjing 210023China No.93721 Army of PLA Shuozhou 038300China

Based on the Regional Specialized Meteorological Center(RSMC)Tokyo-Typhoon Center best-track data and the NCEP-NCAR reanalysis dataset,extratropical transitioning(ET)tropical cyclones(ETCs)over the western North Pacific(WNP)during 1951–2021 are classified into six clusters using the fuzzy c-means clustering method(FCM)according to their track patterns.The characteristics of the six hard-clustered ETCs with the highest membership coefficient are shown.Most tropical cyclones(TCs)that were assigned to clusters C2,C5,and C6 made landfall over eastern Asian countries,which severely threatened these regions.Among landfalling TCs,93.2%completed their ET after landfall,whereas 39.8%of ETCs completed their transition within one day.The frequency of ETCs over the WNP has decreased in the past four decades,wherein cluster C5 demonstrated a significant decrease on both interannual and interdecadal timescales with the expansion and intensification of the western Pacific subtropical high(WPSH).This large-scale circulation pattern is favorable for C2 and causes it to become the dominant track pattern,owning to it containing the largest number of intensifying ETCs among the six clusters,a number that has increased insignificantly over the past four decades.The surface roughness variation and three-dimensional background circulation led to C5 containing the maximum number of landfalling TCs and a minimum number of intensifying ETCs.Our results will facilitate a better understanding of the spatiotemporal distributions of ET events and associated environment background fields,which will benefit the effective monitoring of these events over the WNP.

关键词： Western North Pacific tropical cyclone extratropical transition fuzzy c-means clustering method

Climatic impacts induced by winter wheat irrigation over North China simulated by the nonhydrostatic RegCM4.7

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Advances in Climate Change Research 2024年第2期15卷 197-210页

作者： Jia wu zhen-Yu HAN Xue-Jie GAO zheng-Jia liu National Climate Centre China Meteorological AdministrationBeijing 100081China Key Laboratory for Climate Studies China Meteorological AdministrationBeijing 100081China Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Quantification of the impact of winter wheat irrigation on the climate and the occurrence of extreme climatic events over North China is crucial for regional adaptation planning.Previous related studies mainly focused on the impact on surface processes;however,few focused on the effects of extreme events using high-resolution nonhydrostatic regional climate models.Here,the 9-km-resolution nonhydrostatic RegCM4.7 was coupled with a crop irrigation scheme and an updated winter wheat irrigation dataset to better simulate irrigation effects.Two experiments were conducted with and without winter wheat irrigation to isolate the effects of irrigation.Results showed that irrigation simulation reduces the model biases in temperature,precipitation,latent heat flux,soil moisture,sensitive heat flux,and top-layer soil moisture.Moreover,it also reduces the bias and increases the correlation with observations obtained in irrigated areas,especially in summer,indicating better representation of irrigation schemes.Winter wheat irrigation tends to cause substantial cooling of the local surface maximum,minimum,and mean air temperatures(by-1.68,-0.34,and-0.79℃,respectively)over irrigated areas of North China,with the largest changes observed in relation to maximum temperature.Additionally,precipitation is found to increase during spring and summer,which is strongly related to water vapor transport in the lower levels of the atmosphere.Further analyses indicated that the number of annual mean hot days decrease(-13.9 d),whereas the number of both comfort days(+10.2 d)and rainy days(days with total precipitation greater than 1 mm:+6.6 d)increase over irrigated areas,demonstrating beneficial feedback to human perception and agriculture.Fortunately,although the heat wave risk increases(number of annual mean heat wave days:+5.8 d),the impact is limited to small areas within irrigated region.Additionally,no notable change was found in terms of heavy rainfall events and precipitation intensity,which might be an undereastimation caused by th

关键词： Nonhydrostatic regional climate model Irrigation effect Extreme events North China

Neural network study of the nuclear ground-state spin distribution within a random interaction ensemble

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Nuclear Science and Techniques 2024年第3期35卷 216-227页

作者： Deng liu Alam Noor A zhen-zhen Qin Yang Lei School of Mathematics and Physics Southwest University of Science and TechnologyMianyang 621010China School of Nuclear Science and Technology Southwest University of Science and TechnologyMianyang 621010China

The distribution of the nuclear ground-state spin in a two-body random ensemble(TBRE)was studied using a general classification neural network(NN)model with two-body interaction matrix elements as input features and the corresponding ground-state spins as labels or output predictions.The quantum many-body system problem exceeds the capability of our optimized NNs in terms of accurately predicting the ground-state spin of each sample within the TBRE.However,our NN model effectively captured the statistical properties of the ground-state spin because it learned the empirical regularity of the ground-state spin distribution in TBRE,as discovered by physicists.

关键词： Neural network Two-body random ensemble Spin distribution of nuclear ground state