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Modelling of the elastoplastic behaviour of the bio-cemented soils using an extended Modified Cam Clay model

Atmospheric and Climate Sciences（大气和气候科学） 2021年第3期

作者： Kombo Hamad Kai Yohanna Wilson Shaghude Agnes Lawrence Kijazi christian b.uiso

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第6期16卷 2184-2197页

作者： Xuerui Wang christian b.Silbermann Thomas Nagel Udo Nackenhorst Institute of Mechanics and Computational Mechanics Leibniz UniversitätHannoverAppelstr.9aHannover30167Germany Gesellschaft für Anlagen-und Reaktorsicherheit(GRS)gGmbH Theodor-Heuss-Straße 4Braunschweig38122Germany Geotechnical Institute Technische Universität BergakademieFreibergGustav-Zeuner-Str.1Freiberg09599Germany

An elastoplastic constitutive model based on the Modified Cam Clay(MCC)model is developed to describe the mechanical behaviour of soils cemented via microbially induced calcite precipitation(MICP).It considers the increase of the elastic stiffness,the change of the yield surface due to MICP cementation and the degradation of calcium carbonate bonds during ***,to capture the typical contraction-dilation transition in MICP soils,the original volumetric hardening rule in the MCC model is modified to a combined deviatoric and volumetric hardening *** model could reproduce a series of drained triaxial tests on MICP-treated soils with different calcium carbonate ***,we carry out a parametric study and observe numerical instability in some *** combination with an analytical analysis,our numerical modelling has identified the benefits and limitations of using MCCbased models in the simulation of MICP-cemented soils,leading to suggestions for further model development.

关键词： Microbially induced calcite precipitation(MICP) Elastoplasticity Modified cam clay(MCC) OpenGeoSys MFront Contraction-dilation transition

Experimental studies on the energy dissipation of bolted structures with frictional interfaces:A review

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Friction 2024年第8期12卷 1623-1654页

作者： Yongfeng WANG Yanhong MA Jie HONG Giuseppe b.ATTIATO christian M.FIRRONE School of Energy and Power Engineering Beihang UniversityBeijing 102206China Research Institute of Aero-Engine Beihang UniversityBeijing 102206China Politecnico di Torino Department of Mechanical and Aerospace EngineeringTorino 10139Italy

bolted joints play a more and more important role in the structure with lighter weight and heavier *** paper aims to provide an overview of different experimental approaches for the dynamic behavior of structures in the presence of bolted joints,especially the energy dissipation or damping at frictional *** comprehension of energy dissipation mechanisms due to friction is provided first,while the key parameters and the measurement techniques,such as the excitation force,the preload of the bolt,or the pressure at the interfaces,are briefly ***,the round-robin systems aim to measure the hysteresis parameters of the frictional joints under tangential loads are reviewed,summarizing the basic theory and the strategies to apply the excitation force or acquire the response in different testing *** by parameter identification strategies for bolted structures,the test rigs with one or more simplified bolted joints are summarized to give an insight into the understanding of typical characteristics of bolted structures,which are affected by the presence of *** complex test rigs hosting real-like or actual engineering structures with bolted lap or flange joints are also introduced to show the identification process of the dynamic characteristics of bolted connections employed in specific *** on the review paper,researchers can get the basic knowledge about the experimental systems of the bolted structures,especially several classical round robin systems,such as the Gaul resonator and widely used brake-Reußbeam *** can take advantage of this background for more creative and effective future studies,make more progress on the study of assembled structures and understand the influence of bolting frictional connections on the dynamic response better.

关键词： review study bolted joints frictional damping experimental rigs measurements

Degeneration of foundation cushion species induced by ecological constraints can cause massive changes in alpine plant communities

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Science China(Life Sciences) 2024年第4期67卷 789-802页

作者： Jianguo Chen Xufang Chen Lishen Qian Yazhou Zhang bo Li Honghua Shi Lu Sun christian Schöb Hang Sun Key Laboratory for Plant Diversity and biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China University of Chinese Academy of Sciences Beijing 100049China College of Resources and Environment Yunnan Agricultural UniversityKunming 650500China Área de biodiversidad y Conservación Universidad Rey Juan CarlosMóstoles 28933Spain

Foundational cushion plants can re-organize community structures and sustain a prominent proportion of alpine biodiversity,but they are sensitive to climate *** loss of cushion species can have broad consequences for associated *** potential plant community changes with the population dynamics of cushion plants remain,however,*** eight plant communities along a climatic and community successional gradient,we assessed cushion population dynamics,the underlying ecological constraints and hence associated plant community changes in alpine communities dominated by the foundational cushion plant Arenaria *** population dynamics of Arenaria are attributed to ecological constraints at a series of life history *** functions are constrained by increasing associated beneficiary plants;subsequent seedling establishment is constrained by temperature,water and light availability,extreme climate events,and interspecific competition;strong competitive exclusion may accelerate mortality and degeneration of cushion *** with cushion dynamics,species composition,abundance and community structure gradually *** cushion plants completely degenerate,previously cushion-dominated communities shift to relatively stable communities that are overwhelmingly dominated by *** warming may accelerate the degeneration process of *** of this foundational cushion plant will possibly induce massive changes in alpine plant communities and hence ecosystem functions in alpine *** assessment of the population dynamics of foundation species is critical for an effective conservation of alpine biodiversity.

关键词： alpine ecosystem biodiversity change climate change plant community dynamics foundation species global warming population dynamics

Clustering of voltage-gated ion channels as an evolutionary trigger of myelin formation

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Neural Regeneration Research 2024年第8期19卷 1631-1632页

作者： Henrike Ohm Simone Rey christian Klambt Institut fur Neuro-und Verhaltensbiologie MunsterGermany

Neurons carry apical dendrites that perceive information and a basal axon that transmits the computed information towards its to *** axon originates at the axon hillock which is followed by the axon initial ***,action potentials are initiated that are based on millisecond long openings of specific voltagegated sodium and potassium channels that are conserved in all parahoxozoa(Placozoa,Cnidaria,bilateria)(Li et al.,2015).

关键词： initiated carry potassium

Risk predictors of post-hepatectomy liver failure: unraveling complexities and navigating challenges in clinical application

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Hepatobiliary Surgery and Nutrition 2024年第3期13卷 500-504页

作者： Marc-Anthony Chouillard christian Hobeika Département de Chirurgie Hépato-bilio-Pancréatique et de Transplantation Hépatique Hôpital BeaujonAP-HPUniversitéParis-CitéClichyFrance UMR Inserm 1275 CAP Paris-Tech Hôpital LariboisièreUniversitéParis-CitéParisFrance

Studies related to the prediction of post-hepatectomy liver failure(PHLF)have seen a surge in recent literature.A PubMed search using the terms((“pred*”OR“nomogra*”OR“model*”)AND(“mortality”OR“liver failure”OR“PHLF”)AND(“hepatect*”OR“liver resect*”))revealed 29 relevant studies on PHLF prediction between January 2020 and November 2023,with 20 adhering to grade b/C International Study Group of Liver Surgery(ISGLS)definitions(Table 1).These studies are primarily enrolling patients with hepatocellular carcinoma(HCC).This underscores the growing interest in applying such predictive scores in routine clinical ***,the extent to which these predictive models can be effectively implemented in clinical settings remains unclear(21,22).Indeed,all studies are retrospective,and only a limited number underwent external *** is crucial to recognize that these scores predominantly emerge within surgical cohorts,where patients underwent prior meticulous selection,leading to tailored surgical strategies and the exclusion of specific candidates(21).

关键词： Liver failure modeling prediction hepatectomy

Preventing the Immense Increase in the Life-Cycle Energy and Carbon Footprints of LLM-Powered Intelligent Chatbots

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Engineering 2024年第9期40卷 202-210页

作者： Peng Jiang christian Sonne Wangliang Li Fengqi You Siming You Department of Industrial Engineering and Management Business SchoolSichuan UniversityChengdu 610064China Department of Ecoscience Aarhus UniversityRoskilde DK-4000Denmark Chinese Academy of Sciences Key Laboratory of Green Process and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Systems Engineering Cornell UniversityIthacaNY 14853USA James Watt School of Engineering University of GlasgowGlasgow G128QQUK

Intelligent chatbots powered by large language models(LLMs)have recently been sweeping the world,with potential for a wide variety of industrial *** frontier technology companies are feverishly participating in LLM-powered chatbot design and development,providing several alternatives beyond the famous ***,training,fine-tuning,and updating such intelligent chatbots consume substantial amounts of electricity,resulting in significant carbon *** research and development of all intelligent LLMs and software,hardware manufacturing(e.g.,graphics processing units and supercomputers),related data/operations management,and material recycling supporting chatbot services are associated with carbon emissions to varying *** should therefore be paid to the entire life-cycle energy and carbon footprints of LLM-powered intelligent chatbots in both the present and future in order to mitigate their climate change *** this work,we clarify and highlight the energy consumption and carbon emission implications of eight main phases throughout the life cycle of the development of such intelligent *** on a life-cycle and interaction analysis of these phases,we propose a system-level solution with three strategic pathways to optimize the management of this industry and mitigate the related *** anticipating the enormous potential of this advanced technology and its products,we make an appeal for a rethinking of the mitigation pathways and strategies of the life-cycle energy usage and carbon emissions of the LLM-powered intelligent chatbot industry and a reshaping of their energy and environmental implications at this early stage of development.

关键词： Large language models Intelligent chatbots Carbon emissions Energy and environmental footprints Life-cycle assessment Global cooperation

Efficient removal of the recalcitrant metamizole contaminant from drinking water by using a CaLaCoO_(9) perovskite supported on recycled polyethylene

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Journal of Environmental Sciences 2024年第2期136卷 56-67页

作者： Ernesto Valadez-Renteria christian Perez-Carrasco Dulce Yolotzin Medina-Velazquez Vicente Rodriguez-Gonzalez Jorge Oliva CONACYT-División de Materiales Avanzados Instituto Potosino de Investigación Científica y Tecnológica A.C.San Luis PotosíSLP 78216México División de Ciencias básicas e Ingeniería Universidad Autónoma Metropolitana AzcapotzalcoCol.Reynosa-TamaulipasC.P.MéxicoDF 02200México

Metamizole(MZ)is a widely used anti-inflammatory *** to its common use,this contaminant is found in sewage and *** order to reduce the contamination produced by the MZ,we fabricated in this work a photocatalytic composite using recycled polyethylene(RPE)and the CaLaCoO_(9)(LCCO)*** nanoparticles had a microplate-like morphology and sizes of 1.4–5.5μm according to the analysis of *** photocatalytic properties of the LCCO powders were evaluated under ultraviolet-visible(UV-Vis)irradiation and found a removal efficiency of 96%.When the RPE+LCCO composite was employed for the photocatalytic degradation of MZ,a maximum degradation of 92.5%was *** influence of the pH on the photocatalytic activity was also studied and found that an initial pH=3 produced a total degradation of MZ after 240 min of UV-Vis ***,three reuse cycles were carried out for the pure LCCO powders and for the RPE+LCCO composites and found that the maximum loss of degradation was 5%.Furthermore,scavenger experiments demonstrated that the super oxide and hydroxyl radicals are formed during the photocatalytic reaction and were responsible for the degradation of ***,the X-ray photoelectron-spectroscopy and Raman analysis demonstrated the formation of defects(oxygen vacancies),those ones delayed the electron-hole recombination,which in turn,enhanced the degradation of the ***,the studies performed in this work proved that composites made with recycled plastics and LCCO perovskites are a low-cost and feasible alternative for the cleaning of water sources polluted with pharmaceutical compounds.

关键词： Photocatalysis Metamizole Pharmaceutical contaminant UV-Vis irradiation Perovskite

A Modified Lagrange Method for Solving Convex Quadratic Optimization Problems

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Open Journal of Optimization 2024年第1期13卷 1-20页

作者： Twum b. Stephen Avoka John christian J. Etwire School of Mathematical Science C. K. Tedam University of Technology and Applied Sciences Navrongo Ghana Department of Mathematics University for Development Studies Tamale Ghana

In this paper, a modified version of the Classical Lagrange Multiplier method is developed for convex quadratic optimization problems. The method, which is evolved from the first order derivative test for optimality of the Lagrangian function with respect to the primary variables of the problem, decomposes the solution process into two independent ones, in which the primary variables are solved for independently, and then the secondary variables, which are the Lagrange multipliers, are solved for, afterward. This is an innovation that leads to solving independently two simpler systems of equations involving the primary variables only, on one hand, and the secondary ones on the other. Solutions obtained for small sized problems (as preliminary test of the method) demonstrate that the new method is generally effective in producing the required solutions.

关键词： Quadratic Programming Lagrangian Function Lagrange Multipliers Optimality Conditions Subsidiary Equations Modified Lagrange Method

Root overlap and allocation of above- and belowground growth of European beech in pure and mixed stands of Douglas fir and Norway spruce

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Forest Ecosystems 2024年第5期11卷 591-602页

作者： Amani S.Lwila christian Ammer Oliver Gailing Ludger Leinemann Martina Mun Department of Silviculture&Forest Ecology of the Temperate Zones University of GöttingenBüsgenweg 137077GöttingenGermany Center for biodiversity and Sustainable Land-Use University of GöttingenBüsgenweg 137077GöttingenGermany Department of Forest Genetics and Forest Tree breeding Faculty of Forest Sciences and Forest EcologyUniversity of GöttingenBüsgenweg 237077GöttingenGermany Forestry Research and Competence Centre Gotha Jägerstraße 1D-99867Germany

Site conditions and species identity have a combined effect on fine root growth of trees in pure and mixed ***,mechanisms that may contribute to this effect are rarely studied,even though they are essential to assess the potential of species to cope with climate *** study examined fine root overlap and the linkage between fine root and stem growth of European beech(Fagus sylvatica)growing in pure and mixed stands with Douglas fir(Pseudotsuga menziesii)or Norway spruce(Picea abies)at two different study sites in northwestern *** study sites represented substantially different soil and climate *** each site,three stands,and at each stand,three pairs of trees were *** the pure beech stand,the pairs consisted of two beech trees,while in the mixed stands each pair was composed of a beech tree and a *** each pair,three evenly spaced soil cores were taken monthly throughout the growing *** the pure beech stands,microsatellite markers were used to assign the fine roots to individual *** in stem diameter of beech were quantified and then upscaled to aboveground wood productivity with automatic high-resolution circumference *** found that fine root overlap between neighboring trees varied independently of the distance between the paired trees or the stand types(pure versus mixed stands),indicating that there was no territorial *** wood productivity(wood NPP)and fine root productivity(root NPP)showed similar unimodal seasonal patterns,peaking in ***,this pattern was more distinct for root NPP,and root NPP started earlier and lasted longer than wood *** influence of site conditions on the variation in wood and root NPP of beech was stronger than that of stand *** NPP was,as expected,higher at the richer site than at the poorer *** contrast,root NPP was higher at the poorer than at the richer *** concluded that beech can respond to limited resources

关键词： Fine root growth Stem growth Trade-off Cost-benefit ratio belowground territoriality Conspecific neighbors Heterospecific neighbors