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Experimental study of face passive failure features of a shallow shield tunnel in coastal backfill sand

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Frontiers of Structural and Civil Engineering 2024年第2期18卷 252-271页

作者： weifeng QIAN Ming HUANG Bingnan WANG Chaoshui XU Yanfeng HU School of Civil Engineering Fuzhou UniversityFuzhou 350108China School of Civil Environment and Mining EngineeringUniversity of AdelaideAdelaide 5005Australia China First Highway Xiamen Engineering Co. Ltd.Xiamen 361000China

Face passive failure can severely damage existing structures and underground utilities during shallow shield tunneling,especially in coastal backfill sand.In this work,a series of laboratory model tests were developed and conducted to investigate such failure,for tunnels located at burial depth ratios for which C/D=0.5,0.8,1,and 1.3.Support pressures,the evolution of failure processes,the failure modes,and the distribution of velocity fields were examined through model tests and numerical analyses.The support pressure in the tests first rose rapidly to the elastic limit and then gradually increased to the maximum value in all cases.The maximum support pressure decreased slightly in cases where C/D=0.8,1,and 1.3,but the rebound was insignificant where C/D=0.5.In addition,the configuration of the failure mode with C/D=0.5 showed a wedge-shaped arch,which was determined by the outcropping shear failure.The configuration of failure modes was composed of an arch and the inverted trapezoid when C/D=0.8,1,and 1.3,in which the mode was divided into lower and upper failure zones.

关键词： tunnel face stability passive failure model test support pressure failure mode

Crosslinked solubilizer enables nitrate-enriched carbonate polymer electrolytes for stable,high-voltage lithium metal batteries

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Science Bulletin 2024年第2期69卷 209-217页

作者： Chuyang Jing Kuan Dai Dong Liu Wenran Wang Libao Chen Chunxiao Zhang weifeng Wei State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China College of Materials and Chemical Engineering Hunan Institute of EngineeringXiangtan 411104China

High-voltage lithium metal batteries(LMBs)have been considered promising next-generation highenergy-density batteries.However,commercial carbonate electrolytes can scarcely be employed in LMBs owing to their poor compatibility with metallic lithium.N,N-dimethylacrylamide(DMAA)-a crosslinkable solubilizer with a high Gutmann donor number-is employed to facilitate the dissolution of insoluble lithium nitrate(LiNO3)in carbonate-based electrolytes and to form gel polymer electrolytes(GPEs)through in situ polymerization.The Lit solvation structure of the GPEs is regulated using LiNO3 and DMAA,which suppresses the decomposition of LiPFe and facilitates the formation of an inorganic-rich solid electrolyte interface.Consequently,the Coulombic efficiency(CE)of the LillCu cell assembled with a GPE increases to 98.5%at room temperature,and the high-voltage LillNCM622 cell achieves a capacity retention of 80.1%with a high CE of 99.5%after 400 cycles.The bifunctional polymer electrolytes are anticipated to pave the way for next-generation high-voltage LMBs.

关键词： Crosslinked solubilizer Lithium nitrate Carbonate electrolytes Gel polymer electrolytes Lithium metal batteries

Reheat effect on the improvement in efficiency of the turbine driven by pulse detonation

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Defence Technology（防务技术） 2024年第1期31卷 200-210页

作者： Junyu Liu Zhiwu Wang Zixu Zhang Junlin Li weifeng Qin Jingjing Huang School of Power and Energy Northwestern Polytechnical UniversityXi’an 710072China Shenzhen Research Institute of Northwestern Polytechnical University Shenzhen 518057China Mechanical Engineering College Xi’an Shiyou UniversityXi’an 710065China

Due to the strong unsteadiness of pulse detonation,large flow losses are generated when the detonation wave interacts with the turbine blades,resulting in low turbine efficiency.Considering that the flow losses are dissipated into the gas as heat energy,some of them can be recycled during the expansion process in subsequent stages by the reheat effect,which should be helpful to improve the detonationdriven turbine efficiency.Taking this into account,this paper developed a numerical model of the detonation chamber coupled with a two-stage axial turbine,and a stoichiometric hydrogen-air mixture was used.The improvement in turbine efficiency attributable to the reheat effect was calculated by comparing the average efficiency of the stages with the efficiency of the two-stage turbine.The research indicated that the first stage was critical in suppressing the flow unsteadiness caused by pulse detonation,which stabilized the intake condition of the second stage and consequently allowed much of the flow losses from the first stage to be recycled,so that the efficiency of the two-stage turbine was improved.At a 95%confidence level,the efficiency improvement was stable at 4.5%—5.3%,demonstrating that the reheat effect is significant in improving the efficiency of the detonation-driven turbine.

关键词： Pulse detonation turbine engine Hydrogen detonation Turbine efficiency Reheat effect Multi-cycle detonation

The GNSS PWV retrieval using non-observation meteorological parameters based on ERA5 and its relation with precipitation

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Geodesy and Geodynamics 2024年第3期15卷 302-313页

作者： weifeng Yang Zhiping Chen Kaiyun Lv Pengfei Xia Tieding Lu School of Surveying and Geoinformation Engineering East China University of TechnologyNanchang 330013China Key Laboratory of Mine Environmental Monitoring and Improving around Poyang Lake of Ministry of Natural Resources East China University of TechnologyNanchang 330013China State Key Laboratory of Geodesy and Earth's Dynamics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430077China Jiangxi Province Engineering Research Center of Surveying Mapping and Geographic InformationNanchang 330025China School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China

The pressure and temperature significantly influence precipitable water vapor(PWV) retrieval. Global Navigation Satellite System(GNSS) PWV retrieval is limited because the GNSS stations lack meteorological sensors. First, this article evaluated the accuracy of pressure and temperature in 68 radiosonde stations in China based on ERA5 Reanalysis data from 2015 to 2019 and compared them with GPT3model. Then, the accuracy of pressure and temperature calculated by ERA5 were estimated in 5 representative IGS stations in China. And the PWV calculated by these meteorological parameters from ERA5(ERA5-PWV) were analyzed. Finally, the relation between ERA5-PWV and precipitation was deeply explored using wavelet coherence analysis in IGS stations. These results indicate that the accuracy of pressure and temperature of ERA5 is better than the GPT3 model. In radiosonde stations, the mean BIAS and MAE of pressure and temperature in ERA5 are-0.41/1.15 hpa and-0.97/2.12 K. And the mean RMSEs are 1.35 hpa and 2.87 K, which improve 74.77% and 40.58% compared with GPT3 model. The errors of pressure and temperature of ERA5 are smaller than the GPT3 model in bjfs, hksl and wuh2, and the accuracy of ERA5-PWV is improved by 18.77% compared with the GPT3 model. In addition, there is a significant positive correlation between ERA5-PWV and precipitation. And precipitation is always associated with the sharp rise of ERA5-PWV, which provides important references for rainfall prediction.

关键词： ERA5 GNSS Precipitable water vapor Precipitation Wavelet coherence analysis

Cerium refinement of grains and primary carbides during solidification of Cr_(4)Mo_(4)V bearing steel

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Journal of Rare Earths 2024年第4期42卷 783-792页

作者： weifeng Liu Jianqiang Wang Mingyue Sun Bin Xu Jiahao Yao Qunbo Fan Dianzhong Li Chongqing Innovation Center Beijing Institute of TechnologyChongqing401135China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The effect of cerium(Ce)on the solidification microstructure of Cr_(4)Mo_(4)V bearing steel was investigated via a combined experimental and theoretical method.With a trace amount(0.056 wt%)of Ce addition,the coarse columnar grains in as-cast microstructure transform into equiaxed ones,and the average diameter is reduced from 56 to 27μm.The network-like and bulky primary MC and M2C carbides at the interdendritic regions become disconnected and refined,and their volume percentage decreases from4.15 vol%to 2.1 vol%.Ce-inclusions acting as heterogeneous nucleation agents of prior-austenite grains and Ce atoms segregating at grain boundaries,both contribute to the refinement of grains.Thermodynamic calculations reveal that primary carbides are precipitated afterγ-austenite forms near the end of the solidification process.The modification of primary carbides in size and amount is mainly attributed to the isolated remaining melt separated by refinedγ-austenite grains in which the nucleation of carbides is promoted,while the growth is restrained owing to the less segregation of alloying elements.

关键词： Cr_(4)Mo_(4)V bearing steel Rare Earths Grains Primary carbides Refinement

Adaptable "bubble particles" prepared by green aqueous phase reshaping for completely removing odor

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Nano Research 2024年第3期17卷 2172-2180页

作者： Jiajia Ma Yichang Xia Tienan Zhao Wenfeng Hu weifeng Zhang Qinfei Ke Yi Zhao Shanghai Frontiers Science Center of Advanced Textiles Donghua UniversityShanghai 201620China Engineering Research Center of Technical Textiles Ministry of EducationDonghua UniversityShanghai 201620China School of Fashion Engineering Central Laboratory Shanghai University of Engineering ScienceShanghai 201620China Department of Materials Science and Engineering National University of SingaporeSingapore 117575Singapore School of Perfume and Aroma Technology Shanghai Institute of TechnologyShanghai 201418China

Facile and ecofriendly loading of micro/nano function-specific substances to create functional materials is a trend being pursued by researchers.However,current micro/nano particles loading approaches are often hindered by issues such as uneven distribution,unsatisfactory stability and complicate procedure.In this work,we present an aqueous phase reshaping method that only utilizes the moisture to fabricate the"bubble particles",which could perfectly cater to the topography of the substrate.The green preparation of bubble particles adopts an absolutely zero-pollution method,realizing the firm loading of particles on the substrate.Integrating the preparation and loading of particles overcomes the traditional complicate process,while the aqueous phase reshaping ensures uniform and firm loading of the"bubble particles"onto the substrate.Our mechanism demonstrates a significant enhancement in the interface relation after aqueous phase reshaping,with a 121-fold increase in contact surface area achieved by reducing the height by 1μm.Furthermore,we explore for the first time the influence of the nature of the receiving substrate on the interface morphology of particles during electrostatic spraying,which has important guiding significance for the interface relationship of electrostatic spraying and even electrostatic spinning materials.We also screen out the natural antibacterial essential oil linalool as the effective specialized antibacterial agent,which can specifically inhibit the odor-producing Proteus in urine,with an antibacterial rate of up to 100%.Taken together,this simple,ecofriendly method for fabricating functional materials with optimal interface stability appears highly promising for use in various products formed by electrostatic spraying/spinning.

关键词： bubble particle electrostatic spraying aqueous phase reshaping interface bonding remove odor nano spraying

Spatiotemporal changes in sunshine duration and its influential factors in Chongqing,China from 1961 to 2020

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Journal of Mountain Science 2024年第6期21卷 2005-2024页

作者： LI Jun XIA Hongxuan JIANG Jinge XU weifeng WEN Di XU Junfeng College of Geography and Tourism Chongqing Normal UniversityChongqing 401331China Key Laboratory of GIS Application of Chongqing Chongqing 401331China Chongqing Key Laboratory of Earth Surface Processes and Environmental Remote Sensing in Three Gorges Reservoir area Chongqing 401331China Institute of Remote Sensing and Earth Sciences School of Institute of Remote Sensing and Earth SciencesSchool of ScienceHangzhou Normal UniversityHangzhou 311121China

The surface solar radiation in most parts of the world has undergone a phenomenon known as global dimming and brightening,characterized by an initial decrease followed by an increase.As a result,the sunshine duration(SD)has decreased in the past 60 years.Against the backdrop of global dimming and brightening,SD has decreased to varying degrees in many regions of China.Using the observed data of SD,cloud amount(total cloud amount and low cloud amount,abbreviated as TCA and LCA),precipitation,and relative humidity(RH)from 34 meteorological stations in Chongqing during the period of 1961-2020,along with a digital elevation model(DEM)with a resolution of 90 m,this study analyzed the spatiotemporal variations and influencing factors of SD.The analysis employed methods such as linear regression,Mann-Kendall test,wavelet transformation,and DEM-based possible SD distributed model.The results showed that the annual SD in Chongqing has significantly decreased over the last 60 years,with a decreasing interannual trend rate(ITR)of 40.4 h/10a.Except for no obvious trend in spring,SD decreased significantly in summer,autumn and winter at the ITR of 21.1 h/10a,8.5 h/10a and 7.5 h/10a,respectively.An abrupt decrease in the annual SD was found in 1979.The difference before and after the abrupt decrease was 177.7 h.The difference before and after the abrupt decrease was 177.7 h.The annual SD possessed the oscillation period of 11a.The spatial heterogeneity of the mean annual SD during the last 60 years was obvious.The distribution of SD in Chongqing is high in the northeast and low in the southeast.In addition,about 73%of the total area in Chongqing showed a significant and very significant decreasing trend.The regions with significant changes are mainly concentrated in the regions with altitudes of 200~1000 m.The increasing LCA was the main cause of the decrease of the annual SD in the regions with 200-400 m altitude decreased the most and changed the most.Increasing LCA is the primary cause of the reduction in annual SD,showing

关键词： Sunshine duration Spatiotemporal changes Mann-Kendall test Wavelet analysis Geodetector model

Molecular mechanisms underlying microglial sensing and phagocytosis in synaptic pruning

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Neural Regeneration Research 2024年第6期19卷 1284-1290页

作者： Anran Huo Jiali Wang Qi Li Mengqi Li Yuwan Qi Qiao Yin weifeng Luo Jijun Shi Qifei Cong Clinical Research Center of Neurological Disease The Second Affiliated Hospital of Soochow UniversityInstitute of Neuroscience and Jiangsu Key Laboratory of Neuropsychiatric Diseases Soochow University Department of Neurology and Clinical Research Center of Neurological Disease The Second Affiliated Hospital of Soochow University

Microglia are the main non-neuronal cells in the central nervous system that have important roles in brain development and functional connectivity of neural circuits. In brain physiology, highly dynamic microglial processes are facilitated to sense the surrounding environment and stimuli. Once the brain switches its functional states, microglia are recruited to specific sites to exert their immune functions, including the release of cytokines and phagocytosis of cellular debris. The crosstalk of microglia between neurons, neural stem cells, endothelial cells, oligodendrocytes, and astrocytes contributes to their functions in synapse pruning, neurogenesis, vascularization, myelination, and blood-brain barrier permeability. In this review, we highlight the neuron-derived “find-me,” “eat-me,” and “don’t eat-me” molecular signals that drive microglia in response to changes in neuronal activity for synapse refinement during brain development. This review reveals the molecular mechanism of neuron-microglia interaction in synaptic pruning and presents novel ideas for the synaptic pruning of microglia in disease, thereby providing important clues for discovery of target drugs and development of nervous system disease treatment methods targeting synaptic dysfunction.

关键词： complement immune signals microglia molecular signal synapse elimination synapse formation synapse refinement synaptic pruning

Genetic landscape and clinical significance of cuproptosis-related genes in liver hepatocellular carcinoma

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Genes & Diseases 2024年第2期11卷 516-519页

作者： Dingtao Hu Yichuan Wang Xu Shen Tiantian Mao Xijun Liang Tengjiao Wang weifeng Shen Yugang Zhuang Jin Ding Clinical Cancer Institute Center for Translational MedicineNaval Medical UniversityShanghai 200433China Department of Emergency Shanghai Tenth People's HospitalTongji UniversitySchool of MedicineShanghai 200072China Bioinformatics Analysis Laboratory Center for Translational MedicineNaval Medical UniversityShanghai 200433China The Department of Hepatic Surgery Eastern Hepatobiliary Surgery HospitalNaval Medical UniversityShanghai 200433China

Recently,Peter et al reported a novel form of cell death(cuproptosis)that was different from other known death mechanisms.1 They found that accumulation of copper ions could induce destabilization of Fe-S cluster proteins and aggregation of mitochondrial lipoylated proteins,ultimately resulting in cuproptosis.1 of note,ten genes were identified as cuproptosis-related genes(CRGs)in copper ion-induced cell death,including PDHB,PDHA1,DLAT,DLD,LIPT1,LIAS,FDX1,CDKN2A,GLS,and MTF1.1 Since dysregulation of copper metabolism is involved in many cancers,cuproptosis and CRGs may play vital roles in cancer development and treatment.1.2 Herein,our pancancer analysis revealed the coordinated upregulation of 9 of 10 CRGs in human liver hepatocellular carcinoma(LIHC)across 33 solid tumors(Fig.S1A;Fig.1A),suggesting the distinct role of CRGs in LIHC.We then explored the genetic landscape,biological function,and clinical significance of CRGs in LIHC,and validated our bioinformatic findings by in vitro experiments and clinical cohorts.The detailed methods were described in the supplementary material.

关键词： clinical metabolism hepatocellular