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Effect of the sloping seabed on 3D soil-spudcan interaction using a material point-finite element(MPM-FEM)model

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1436-1454页

作者： Zhengda Lei Guangtian Zeng Huaihui ren Bisheng Wu Yuxin Jie State Key Laboratory of Hydroscience and Engineering Department of Hydraulic EngineeringTsinghua UniversityBeijingChina Key Laboratory of the Hydrosphere Sciences of the Ministry of Water Resources BeijingChina Institute of Ocean Engineering Tsinghua UniversityBeijingChina Longyuan (Beijing) Wind Power Engineering Technology Co. Ltd.BeijingChina

The sloping seabed affects the bearing capacity and failure mechanism of soil,which may compromise the stability and safety of offshore structures such as jack-up *** paper employs a coupled model combining the material point method and finite element method(MPM-FEM)to analyze the impact of sloping seabeds on the three-dimensional soil-spudcan *** MPM-FEM model implements the B¯approach to solve the challenge of volumetric locking due to the incompressibility constraints imposed by yield *** is validated against the centrifuge *** effects of sloping seabeds on penetration resistance,soil flow pattern,lateral response,stress distribution,and failure mechanism are *** soil mainly undergoes overall failure when the ratio of penetration depth to spudcan diameter(i.e.D P/D)is between 0 and *** the slope angle increases,the soil on the side of lower slope is expelled further,resulting in an asymmetric stress distribution and a larger horizontal sliding force of *** D P/D increases to 0.75,the soil transitions to localized plastic flow failure,and the range of soil flow affected by the spudcan penetration *** results show that,when the slope angle increases,the lateral displacement and stress distribution on the lower slope of a sloping seabed is significantly larger than that of a horizontal seabed,impacting the spudcan and surrounding soil *** study suggests that the seabed slope significantly affects the range of soil flow and failure at shallow penetration,indicating that the slope angle should be taken into account in the design and installation of offshore jack-up rigs,particularly in areas with sloping seabeds.

关键词： Soil-spudcan interaction Centrifuge tests MPM-FEM model B—approach Sloping seabeds Offshore structures

Rbm8a regulates neurogenesis and reduces Alzheimer's disease-associated pathology in the dentate gyrus of 5×FAD mice

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Neural Regeneration Research 2024年第4期19卷 863-871页

作者： Chenlu Zhu Xiao ren Chen Liu Yawei Liu Yonggang Wang Department of Neurology Lanzhou University Second Hospital Department of Neurology The First Affiliated Hospital of Nanchang University Department of Neurology Xiaogan City Central Hospital Health Service Department of the Guard Bureau of the General Office of the Central Committee of the Communist Party of China Headache Center Department of NeurologyBeijing Tiantan HospitalCapital Medical University

Alzheimer’s disease is a prevalent and debilitating neurodegenerative condition that profoundly affects a patient’s daily functioning with progressive cognitive decline,which can be partly attributed to impaired hippocampal *** in the hippocampal dentate gyrus is likely to persist throughout life but declines with aging,especially in Alzheimer’s *** evidence indicated that RNA-binding protein 8A(Rbm8a)promotes the proliferation of neural progenitor cells,with lower expression levels observed in Alzheimer’s disease patients compared with healthy *** study investigated the hypothesis that Rbm8a overexpression may enhance neurogenesis by promoting the proliferation of neural progenitor cells to improve memory impairment in Alzheimer’s ***,Rbm8a overexpression was induced in the dentate gyrus of 5×FAD mice to validate this *** Rbm8a levels in the dentate gyrus triggered neurogenesis and abated pathological phenotypes(such as plaque formation,gliosis reaction,and dystrophic neurites),leading to ameliorated memory performance in 5×FAD *** sequencing data further substantiated these findings,showing the enrichment of differentially expressed genes involved in biological processes including neurogenesis,cell proliferation,and amyloid protein *** conclusion,overexpressing Rbm8a in the dentate gyrus of 5×FAD mouse brains improved cognitive function by ameliorating amyloid-beta-associated pathological phenotypes and enhancing neurogenesis.

关键词： Adora2a Alzheimer’s disease astrocyte cAMP signaling pathway dentate gyrus dystrophic neurites microglia neurogenesis plaque Rbm8a

Wireless semantic communication based on semantic matching multiple access and intent bias multiplexing

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 26-36页

作者： ren Chao He Zongrui Sun Chen Li Haojin Zhang Haijun University of Science and Technology Beijing Beijing 100083China Research and Development Center Sony(China)LimitedBeijing 100027China

This paper proposes a multi-access and multi-user semantic communication scheme based on semantic matching and intent deviation to address the increasing demand for wireless users and *** scheme enables flexible management of long frames,allowing each unit of bandwidth to support a higher number of *** leveraging semantic classification,different users can independently access the network through the transmission of long concatenated sequences without modifying the existing wireless communication *** overcome the potential disadvantage of incomplete semantic database matching leading to semantic intent misunderstanding,the scheme proposes using intent deviation as an *** allows different receivers to interpret the same semantic information differently,enabling multiplexing where one piece of information can serve multiple users with distinct *** results show that at a bit error rate(BER)of 0.1,it is possible to reduce the transmission by approximately 20 semantic basic units.

关键词： semantic communication multiple access multiplexing multimodal communication

Observing eddy dye patches induced by shear instabilities in the surf zone on a plane beach

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Acta Oceanologica Sinica 2024年第3期43卷 15-29页

作者： Chunping ren Nannan Fu Chong Yu Yuchuan Bai Kezhao Fang State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China College of Water Resource Science and Engineering Taiyuan University of TechnologyTaiyuan 030024China State Key Laboratory of Coastal and Offshore Engineering Dalian University of TechnologyDalian 116024China

The effects of surf zone eddy generated by alongshore currents on the deformation and transport of dye are still poorly understood,and related tracer release experiments are ***,a tracer release laboratory experiment was conducted under monochromatic,unidirectional incident waves with a large incident angle(30°)on a plane beach with a 1:100 slope in a large wave basin.A charge-coupled device suspended above the basin recorded the dye patch *** evolution of eddy dye patch was observed and the transport and diffusion were analyzed based on the collected ***,a linear instability numerical model was adopted to calculate the perturbation velocity field at the initial *** observation and image processing results show that surf zone eddy patches occurred and were separated from the original dye *** numerical analysis results demonstrate that the structure of the perturbation velocity field is consistent with the experimental observations,and that the ejection of eddy patches shoreward or offshore may be ascribed to the double vortex.

关键词： surf zone tracer release experiment evolution of eddy patch shear instability of alongshore currents

Engineered stem cells by emerging biomedical stratagems

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Science Bulletin 2024年第2期69卷 248-279页

作者： Jinglin Wang Xiaoxuan Zhang Hanxu Chen Haozhen ren Min Zhou Yuanjin Zhao Department of Vascular Surgery.Nanjing Drum Tower Hospital Affliated Hospital of Medical SchoolNanjing UniversityNanjing 210008China Division of Hepatobiliary Surgery and Transplantation Surgery Department of General SurgeryNanjing Drum Tower HospitalSchool of Biological Science and Medical EngineeringSoutheast UniversityNanjing 210096China Shenzhen Research Institute Southeast UniversityShenzhen 518038China

Stem cell therapy holds immense potential as a viable treatment for a widespread range of intractable *** the safety of stem cell transplantation having been demonstrated in numerous clinical trials,various kinds of stem cells are currently utilized in medical *** the achievements,the therapeutic benefits of stem cells for diseases are limited,and the data of clinical researches are *** optimize tthe effectiveness of stem cells,engineering approaches have been developed to enhance their inherent abilities and impart them with new functionalities,paving the way for the next generation of stem cell *** review offers a detailed analysis of engineered stem cells,including their clinical applications and potential for future *** begin by briefly introducing the recent advances in the production of stem cells(induced pluripotent stem cells(ipsCs),embryonic stem cells(ESCs),mesenchymal stem cells(MSCs)and hematopoietic stem cells(HSCs).Furthermore,we present the latest developments of engineered strategies in stem cells,including engineered methods in molecular biology and biomaterial fields,and their application in biomedical ***,we summarize the current obstacles and suggest future prospects for engineered stem cells in clinical translations and biomedical applications.

关键词： Stem cells Genetic modification Biomaterials Microfluidics Organ-on-a-chip Bioprinting

Pulsed current-assisted twelve-roll precision rolling deformation of SUS304 ultra-thin strips with exceptional mechanical properties

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International Journal of Extreme Manufacturing 2024年第4期6卷 291-305页

作者： Wanwan Fan Tao Wang Jinxiong Hou Zhongkai ren Qingxue Huang Guanghui Wu College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyYingze West Street 79Taiyuan 030024Shanxi ProvincePeople's Republic of China Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment of Ministry of Education Taiyuan University of TechnologyYingze West Street 79Taiyuan 030024Shanxi ProvincePeople's Republic of China National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyYingze West Street 79Taiyuan 030024Shanxi ProvincePeople's Republic of China College of Aeronautics and Astronautics Taiyuan University of TechnologyYingze West Street 79Taiyuan 030024Shanxi ProvincePeople's Republic of China

Innovative pulsed current-assisted multi-pass rolling tests were conducted on a 12-roll mill during the rolling deformation processing of SUS304 ultra-thin *** results show that in the first rolling pass,the rolling reduction rate of a conventionally rolled sample(at room temperature)is 33.8%,which can be increased to 41.5%by pulsed current-assisted rolling,enabling the formation of an ultra-thin strip with a size of 67.3μm in only one rolling *** three passes of pulsed current-assisted rolling,the thickness of the ultra-thin strip can be further reduced to 51.7μ*** clearly compare the effects of a pulsed current on the microstructure and mechanical response of the ultra-thin strip,ultra-thin strips with nearly the same thickness reduction were *** was found that pulsed current can reduce the degree of work-hardening of the rolled samples by promoting dislocation detachment,reducing the density of stacking faults,inhibiting martensitic phase transformation,and shortening the total length of grain *** a result,the ductility of ultra-thin strips can be effectively restored to approximately 16.3%while maintaining a high tensile strength of 1118 ***,pulsed current-assisted rolling deformation shows great potential for the formation of ultra-thin strips with a combination of high strength and ductility.

关键词： pulsedcurrent-assisted SUS304 ultra-thinstrip rolling reductionrate work-hardening mechanical properties

Particle agglomeration and inhibition method in the fluidized pyrolysis reaction of waste resin

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Chinese Journal of Chemical Engineering 2024年第3期67卷 135-147页

作者： Congjing ren Peng Zhang Qi Song Zhengliang Huang Yao Yang Yongrong Yang Ningbo Innovation Center Zhejiang UniversityNingbo 315100China College of Chemical and Biological Engineering Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture TechnologyZhejiang UniversityHangzhou 310027China

This work investigated the pyrolysis reaction of waste resin in a fluidized bed *** was found that the pyrolysis-generated ash would adhere to the surface of ceramic particles,causing particle agglomeration and *** kaolin could effectively inhibit the particle agglomeration during the fluidized pyrolysis reaction through physical isolation and chemical *** the one hand,kaolin could form a coating layer on the surface of ceramic particles to prevent the adhesion of organic ash generated by the pyrolysis of *** the other hand,when a sufficient amount of kaolin(-0.2%(mass))was added,the activated kaolin could fully contact with the Na+ ions generated by the pyrolysis of resin and react to form a high-melting aluminosilicate mineral(nepheline),which could reduce the formation of low-melting-point sodium sulfate and thereby avoid the agglomeration of ceramic particles.

关键词： Pyrolysis reaction of waste resin Fluidization Particle agglomeration Kaolin

The risk factors and threshold level of subchronic inhalation exposure of reclaimed water

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Journal of Environmental Sciences 2024年第3期137卷 639-650页

作者： Jiayang Kong Yun Lu Yunru ren Menghao Chen Gang Liu Liangliang Shi State Key Joint Laboratory of Environment Simulation and Pollution Control State Environment Protection Key Laboratory of Microorganism Application and Risk ControlSchool of EnvironmentTsinghua UniversityBeijing 100084China

Inhalation of reclaimed water is known to cause lung infammation,and free endotoxins have been shown to be a major risk factor for acute *** exposure has also been shown to induce infammatory responses with visible tissue ***,subchronic risk factors have yet to be identified,and a threshold for the protection of occupational populations during urban reuse is *** this study,potential risk factors in reclaimed water were examined by subchronic exposure with fractionated reclaimed water,and the health risk threshold was tested with a series of diluted reclaimed ***,following a 12-week exposure,macromolecules and microorganisms were found to be two major risk factors in reclaimed water that could cause pulmonary infammation,including increased proportion of polymorphonuclear leukocytes in bronchoalveolar fuid,formation of inducible bronchus-associated lymphoid tissue,and elevation of Immunoglobulin A ***,infammation persisted after a 4-week recovery *** calculated threshold of reclaimed water exposure for mice was 31.8 Endotoxin Unit(EU)/(kg·day)under when exposed to 50%additional relative humidity from reclaimed water at 25℃ for 2 hr/***,the subchronic threshold estimate for humans under the same exposure conditions was found to be 12.2 EU/(kg·day),corresponding to endotoxin levels of 61.7 EU/mL in reclaimed *** threshold level of endotoxin was lower than that in most non-potable reclaimed *** findings of this study suggest that occupational exposure of reclaimed water can serve as a potential risk to workers.

关键词： Reclaimed water Inhalation exposure Risk factor Threshold Infammation Endotoxin

Global patterns of soil phosphatase responses to nitrogen and phosphorus fertilization

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Pedosphere 2024年第1期34卷 200-210页

作者： Xiaomei GOU Yongqing ren Xin QIN Xiaorong WEI Jingjing WANG State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau the Research Center of Soil and Water Conservation and Ecological EnvironmentChinese Academy of Sciences and Ministry of EducationYangling 712100China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China River and Lake Management Office Shaanxi Provincial Department of Water ResourcesXi'an 710004China College of Natural Resources and Environment Northwest A&F UniversityYangling 712100China University of Chinese Academy of Sciences Beijing 100049China CAS Center for Excellence in Quaternary Science and Global Change Xi'an 710061China

Hydrolysis of organic phosphorus(P) by soil phosphatases is an important process of P cycling in terrestrial ecosystems, significantly affected by nitrogen(N) and/or P fertilization. However, how soil acid phosphatase(ACP) and alkaline phosphatase(ALP) activities respond to N and/or P fertilization and how these responses vary with climatic regions, ecosystem types, and fertilization management remain unclear. This knowledge gap hinders our ability to assess P cycling and availability from a global perspective. We performed a meta-analysis to evaluate the global patterns of soil ACP and ALP activities in response to N and/or P addition. We also examined how climatic regions(arctic to tropical), ecosystem types(cropland, grassland, and forest), and fertilization management(experiment duration and fertilizer type and application rate) affected changes in soil phosphatases after fertilization. It was shown that N fertilizer resulted in 10.1% ± 2.9% increase in soil ACP activity but a minimal effect on soil ALP activity. In contrast, P fertilizer resulted in 7.7% ± 2.6% decrease in soil ACP activity but a small increase in soil ALP activity. The responses of soil ACP and ALP activities to N and/or P fertilization were largely consistent across climatic regions but varied with ecosystem types and fertilization management, and the effects of ecosystem types and fertilization management were enzyme-dependent. Random forest analysis identified climate(mean annual precipitation and temperature) and change in soil pH as the key factors explaining variations in soil ACP and ALP activities. Therefore, N input and ecosystem types should be explicitly disentangled when assessing terrestrial P cycling.

关键词： acid phosphatase alkaline phosphatase ecosystem type fertilization management meta-analysis phosphorus cycling phosphorus limitation