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Exploring changes of precipitation extremes under climate change through global variable-resolution modeling

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Science Bulletin 2024年第2期69卷 237-247页

作者： Wei Sun Jian Li Rucong Yu nina Li Yi Zhang State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Institute of Tibetan Plateau Meteorology China Meteorological AdministrationChengdu 610072China Department of Atmospheric Science Yunnan UniversityKunming 650091China National Meteorological Center China Meteorological AdministrationBeijing 100081China 2035 Future Laboratory PIESAT Information Technology Co.Ltd.Beijing 100105China

Understanding the responses of precipitation extremes to global climate change remains limited owing to their poor representations in models and complicated interactions with multi-scale *** we take the record-breaking precipitation over China in 2021 as an example,and study its changes under three different climate scenarios through a developed pseudo-global-warming(PGW)experimental framework with 60-3 km variable-resolution global ensemble *** to the present climate,the precipitation extreme under a warmer(cooler)climate increased(decreased)in intensity,coverage,and total amount at a range of 24.3%-37.8%(18.7%-56.1%).With the help of the proposed PGW experimental framework,we further reveal the impacts of the multi-scale system interactions in climate change on the precipitation *** the warmer climate,large-scale water vapor transport converged from double typhoons and the subtropical high marched into central China,enhancing the convective energy and instability on the leading edge of the transport *** a result,the mesoscale convective system(Mcs)that directly contributed to the precipitation extreme became stronger than that in the present *** the contrary,the cooler climate displayed opposite changing characteristics relative to the warmer climate,ranging from the large-scale systems to local environments and to the *** summary,our study provides a promising approach to scientifically assess the response of precipitation extremes to climate change,making it feasible to perform ensemble simulations while investigating the multi-scale system interactions over the globe.

关键词： Precipitation extreme Climate change Pseudo-global-warming experiment Variable-resolution modeling Multi-scale system interaction

Taxonomy and phylogeny of the section Chaetoceros(Chaetocerotaceae,Bacillariophyta),with description of two new species

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Journal of Oceanology and Limnology 2024年第4期42卷 1286-1311页

作者： Xudan LU Mengyi ZHAI nina LUNDHOLM Yang LI Guangdong Provincial Key Laboratory of Biotechnology for Plant Development Guangzhou Key Laboratory of Subtropical Biodiversity and BiomonitoringCollege of Life ScienceSouth China Normal UniversityGuangzhou 510631China Natural History Museum of Denmark University of CopenhagenCopenhagen K 1353Denmark

Chaetoceros Ehrenberg is one of the most diverse genera of planktonic *** species in section Chaetoceros are characterized by cells and setae having numerous chloroplasts and being widely ***,the delimitations of some species are problematic because of limited morphological information in the classical *** strains of the section Chaetoceros were established,morphological features were studied using light and electron microscopy,and the hypervariable D 1-D 3 region of the nuclear ribosomal large subunit gene was sequenced to address phylogenetic *** species belonging to the section Chaetoceros were recorded,including two new species,*** *** *** *** hainanensis was characterized by straight chains,narrowly lanceolate to hexagonal apertures,sibling setae diverging in nearly right angles,stipule-shaped spines on terminal setae and arrowhead-shaped spines on intercalary *** had short straight chains,narrowly lanceolate apertures,arrowhead-shaped spines and circular poroids arranged in a grid pattern on terminal and intercalary *** phylogenetic analyses revealed six groups formed by 19 species within the section Chaetoceros,which was found to be *** subdivision of the section is still not well *** morphological characters within each group varied considerably and molecular information on more species are needed to enrich the phylogenetic profiling.

关键词： morphology large subunit ribosomal RNA encoding gene(LSU) section Chaetoceros Chaetoceros hainanensis Chaetoceros tridiscus

A survey of energy-efficient strategies for federated learning in mobile edge computing

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Frontiers of Information Technology & Electronic Engineering 2024年第5期25卷 645-663页

作者： Kang YAN nina SHU Tao WU Chunsheng LIU Panlong YANG School of Electronic Engineering National University of Defense TechnologyHefei 230009China Department of Computing Hong Kong Polytechnic UniversityHong Kong 999077China School of Computer Science and Technology University of Science and Technology of ChinaHefei 230026China

With the booming development of fifth-generation network technology and Internet of Things,the number of end-user devices(EDs)and diverse applications is surging,resulting in massive data generated at the edge of *** process these data eficiently,the innovative mobile edge computing(MEC)framework has emerged to guarantee low latency and enable eficient computing close to the user ***,federated learning(FL)has demonstrated its empirical success in edge computing due to its privacy-preserving ***,it becomes a promising solution for analyzing and processing distributed data on EDs in various machine learning tasks,which are the major workloads in ***,EDs are typically powered by batteries with limited capacity,which brings challenges when performing energy-intensive FL *** address these challenges,many strategies have been proposed to save energy in *** the absence of a survey that thoroughly summarizes and classifies these strategies,in this paper,we provide a comprehensive survey of recent advances in energy-efficient strategies for FL in ***,we first introduce the system model and energy consumption models in FL,in terms of computation and *** we analyze the challenges regarding improving energy efficiency and summarize the energy-efficient strategies from three perspectives:learning-based,resource allocation,and client *** conduct a detailed analysis of these strategies,comparing their advantages and ***,we visually illustrate the impact of these strategies on the performance of FL by showcasing experimental ***,several potential future research directions for energy-efficient FL are discussed.

关键词： Mobile edge computing Federated learning Energy-efficient

APPROXIMATING THE STATIONARY BELLMAN EQUATION BY HIERARCHICAL TENSOR PRODUCTS

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Journal of Computational Mathematics 2024年第3期42卷 638-661页

作者： Mathias Oster Leon Sallandt Reinhold schneider Technische Universität Berlin Strasse des 17.Juni 13510623 BerlinGermany

We treat infinite horizon optimal control problems by solving the associated stationary Bellman equation numerically to compute the value function and an optimal feedback *** dynamical systems under consideration are spatial discretizations of non linear parabolic partial differential equations(PDE),which means that the Bellman equation suffers from the curse of *** non linearity is handled by the Policy Iteration algorithm,where the problem is reduced to a sequence of linear equations,which remain the computational bottleneck due to their high *** reformulate the linearized Bellman equations via the Koopman operator into an operator equation,that is solved using a minimal residual *** the Koopman operator we identify a preconditioner for operator equation,which deems essential in our numerical *** overcome computational infeasability we use low rank hierarchical tensor product approximation/tree-based tensor formats,in particular tensor trains(TT tensors)and multi-polynomials,together with high-dimensional quadrature,*** controlling a destabilized version of viscous Burgers and a diffusion equation with unstable reaction term numerical evidence is given.

关键词： Feedback control Dynamic programming Hamilton-Jacobi-Bellman Tensor product approximation Variational Monte-Carlo

Juvenile survival curves in a solitary ground squirrel with a prolonged hibernation:effects of individual characteristics,environment,and maternal investment

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Current Zoology 2024年第1期70卷 13-23页

作者： nina A.Vasilieva Liudmila E Savinetskaya Andrey V.Tchabovsky A.N.Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscow 119071Russia

Juvenile survival is a key life-history influence on population dynamics and adaptive *** analyzed the effects of individual chara-cteristics,early environment,and maternal investment on juvenile survival in a large solitary hibernating rodent-yellow ground squirrel Spermophilus fulvus using Cox mixed-effects *** 48%of weaned pups survived to dispersal and 17%survived to *** life expectancy was primarily determined by individual characteristics and,to a lesser extent,by the early *** strongest and pos-itive predictor of juvenile survival was body mass which crucially affected mortality immediately after *** suffered higher mortality than females after the onset of dispersal;however,the overall difference between sexes was partly masked by high rates of mortality in the first days after emergence in both *** emerged juveniles had lower life expectancy than the earliest *** overall effect of local juvenile density was *** lactation did not enhance juvenile survival:Pups nursed longer survived shorter than the young nursed for a shorter *** findings support the hypothesis that females of *** cannot effectively regulate maternal expenditures to mitigate the effects of unfavorable conditions on their *** strategy to deal with seasonal time constraints on life history in female *** suggests an early termination of maternal care at the cost of juvenile quality and *** female reproductive strategy corresponds to a"fast-solitary"life of folivorous desert-dwelling *** and other solitary ground squirrels with prolonged hibernation.

关键词： early-life conditions ground squirrels hibernation juvenile mortality maternal investment survival curves

Particle Swarm Optimization Bat Algorithm Path Automatically Planning Research for Police Drones in Hilly Cities

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Journal of Systems Science and Information 2024年第1期12卷 125-144页

作者： Jing XUE Zefu TAN nina DAI Guoping LEI Chao HE Chongqing Three Gorges University Chongqing 404020China

Mountain cities are complex asymmetric dynamic network architectures,and the flight of UAVs in this environment is subject to various constraints,while efficiency is a crucial factor in the trajectory planning of police UAVs,which need to maintain high efficiency and safe flight paths between their starting and ending points,but the traditional trajectory planning method cannot meet the requirements of rapid maneuvering of police *** achieve this,a 3D terrain map is built,an objective function is established for the flight cost in the UAV trajectory planning process,and a planning algorithm called particle swarm optimization bat algorithm(PSOBA)is *** combines the characteristics of the bat algorithm(BA)and the particle swarm optimization algorithm(PSO)to improve population diversity and resolve the delayed convergence issue in the last phases of *** results show that PSOBA is more effective than BA,with a search time for the best solution that is approximately 20.43%shorter and a convergence value of the objective function that is approximately 38%*** is also able to plan a quicker,shorter,and safer flight path compared to other trail planning algorithms that enhance the bat *** findings suggest that PSOBA is a powerful algorithm with potential application value in UAV trajectory planning control in the mobile intelligence *** to the service of public social security.

关键词： hilly cities police drones asymmetrical trajectory planning particle swarm bat algorithm

A cross-cultural study of sustainable nutrition and its environmental impact in Asia and Europe:A comparison of China and Germany

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Regional Sustainability 2024年第2期5卷 1-12页

作者： bir.it Anika RUMPOLD SUN Lingxiao nina LANGEN YU Ruide Department Education for Sustainable Nutrition and Food Science Technical University BerlinBerlin14052Germany State Key Laboratory of Desert and Oasis Ecology Xinjiang Institute of Ecology and GeographyChinese Academy of SciencesUrumqi830011China

Global challenges such as climate change,biodiversity loss,and health crises necessitate a shift towards sustainable *** sustainability into food-based dietary guidelines(FBDGs)is essential for this shift,and cultural considerations also play a vital role,as food culture significantly influences dietary *** that Asia and Europe exhibit distinct food cultures,tailored approaches are ***,countries face diverse nutritional challenges,ranging from malnutrition to diet-related diseases,and regional variation in environmental impact necessitates context-specific *** sustainable nutrition depends on understanding cultural influences and regional *** paper compares China’s and Germany’s dietary guidelines and dietary patterns and their impact on *** shows that Chinese and German FBDGs only slightly differ,despite the different eating cultures and habits of each *** the recommended amounts for eggs and fish are considerably higher in China than in ***,in both China and Germany,actual dietary patterns deviate from the dietary *** China,concomitant with economic growth and urbanization,a dietary shift towards increased consumption of animal products and decreased consumption of vegetables and cereals has been observed in the last decades,which has led to a decline in nutritional deficiencies but an increase in obesity and *** and overweight are also on the rise in Germany.A dietary shift could therefore also be beneficial for public *** following the respective national guidelines would benefit the environment,alternative diets such as a plant-based diet offer even lower environmental *** guidelines to prioritize sustainability in addition to health aspects while considering regional contexts and cultural preferences is recommended to foster sustainable eating habits *** approach is pivotal for promoting die

关键词： Food-based dietary guidelines (FBDGs) Dietary shift Planetary health diet Dietary patterns Sustainable nutrition Greenhouse gas (GHG)emission

Modeling displacement flow inside a full-length casing string for well cementing

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Petroleum Research 2024年第1期9卷 1-16页

作者： Hu Dai Ali Eslami Jason schneider Gefei Liu Fred Schwering Pegasus Vertex Inc.USA Laval University Canada Sanjel Energy Services Canada Athabasca Oil Corporation Canada

While computer modeling of annular displacement efficiency is widely applied in cementing engineering,modeling the displacement flow inside a casing or drill string for cementing operations has received less *** predicting displacement efficiency inside a full-length pipe is desired by cementing engineers,the attempt of developing a model with both efficiency and accuracy faces *** to computer simulators for this purpose is *** with annular flow,the displacement flow inside pipe,although within a simpler geometry and without eccentricity effect,is not simpler in physics,modelling strategy and predictability,because a variety of flow patterns and flow instabilities can develop to create complicated fluid *** this paper,we present an integrated numerical model developed to simulate displacement flows inside a full-length pipe,which connects an existing annulus model to enable complete displacement simulations of cementing *** model uses three-dimensional grid to solve fluid concentrations with degrees of mixing,and incorporates flow instability detection and flow regime *** in cementing,the model accounts for effects of pumping rate,well inclination,pipe rotation,fluid densities,rheological parameters and *** computationally efficient model does not rely on high-resolution mesh as often required by conventional Computational Fluid Dynamics models,thus it is suitable to be implemented in a cementing software for daily use by well cementing *** methodology of the model is discussed in detail in this *** validate the model,we examine simulation results against experimental results obtained in our laboratory tests and CFD simulations;acceptable agreement is found under different testing *** also presented two case studies of real cementing jobs with cement evaluation logs compared to simulation results,showing that the model can predict consistent displacement efficie

关键词： Inside pipe displacement Displacement efficiency Numerical model Primary cementing Displacement flow

Two-photon emission from a superlattice-based superconducting light-emitting structure

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Light(Science & Applications) 2024年第7期13卷 1331-1340页

作者： Shlomi Bouscher Dmitry Panna Ronen Jacovi Fauzia Jabeen Christian schneider Sven Höfling Alex Hayat Department of Electrical Engineering TechnionHaifa 32000Israel. Technische Physik Universität WürzburgAm HublandD-97074 WürzburgGermany. Institute of Physics Carl von Ossietzky Universität OldenburgD-26111 OldenburgGermany

Superconductor-semiconductor hybrid devices can bridge the gap between solid-state-based and photonics-based quantum systems,enabling new hybrid computing schemes,offering increased scalability and *** example for a hybrid device is the superconducting light-emitting diode(SLED).SLEDs have been theoretically shown to emit polarization-entangled photon pairs by utilizing radiative recombination of Cooper ***,the twophoton nature of the emission has not been shown experimentally *** demonstrate two-photon emission in a GaAs/AlGaAs *** electroluminescence spectra reveal unique two-photon superconducting features below the critical temperature(Tc),while temperature-dependent photon-pair correlation experiments(g(2)(τ,T))demonstrate temperature-dependent time coincidences below Tc between photons emitted from the *** results pave the way for compact and efficient superconducting quantum light sources and open new directions in light-matter interaction studies.

关键词： photon quantum utilizing