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随机薄片网络的单轴拉伸强度及缺口不敏感性

中国科学：物理学、力学、天文学 2024年第5期54卷 253-268页

作者：张峰潘飞陈玉丽天目山实验室杭州310023 北京航空航天大学航空科学与工程学院北京100191 厦门双瑞风电科技有限公司厦门361000

由高强度高刚度薄片随机组装而成的片状网络材料具有独特的性能和广泛的应用.然而,网络具有显著的随机和离散特征,这些特征对材料的强度和韧性的影响机理还不明确.为此,本文系统研究了随机薄片网络材料在单轴拉伸载荷下的损伤失效演化过... 详细信息

由高强度高刚度薄片随机组装而成的片状网络材料具有独特的性能和广泛的应用.然而,网络具有显著的随机和离散特征,这些特征对材料的强度和韧性的影响机理还不明确.为此,本文系统研究了随机薄片网络材料在单轴拉伸载荷下的损伤失效演化过程,发现了该类材料强度的缺口不敏感性,并揭示了其机理.研究表明,由于网络材料自身的随机和离散特征,层间连接强弱不均且分布随机,因此在单轴拉伸过程中,损伤从弱连接处萌生,并在空间多点离散分布,最终逐渐汇聚成为主裂纹,使得网络呈现韧性断裂特征.正是由于初始损伤为多点分布形式且缺口尖端应力集中有限,导致了随机薄片网络的强度对缺口的不敏感,且与薄片和层间连接的韧性无关.

关键词：随机薄片网络强度韧性缺口敏感性

A toast to a zebrafish germ cell induction cocktail

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Science china(Life Sciences) 2024年第6期67卷 1314-1315页

作者： Mary c.Mullins Department of cell and Developmental Biology University of Pennsylvania Perelman School of MedicinePhiladelphia 19104USA

The zebrafish field is ringing in the new year with a publication from Yonghua Sun's laboratory(Wang et al.,2023)of a cocktail of germline factors that can induce all cells of the zebrafish embryo into primordial germ cells(PGcs)at phenomenal *** major advance is not only of great interest to germ cell biologists,but it has important applications to the entire zebrafish field,as shown in Wang et al.(2023).

关键词： fish zebra field

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Performance of evolutionary optimized machine learning for modeling total organic carbon in core samples of shale gas fields

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Petroleum 2024年第1期10卷 150-164页

作者： Leonardo Goliatt c.M.Saporetti L.c.Oliveira E.Pereira Department of computational and Applied Mechanics Federal University of Juiz de Fora Department of computational Modeling Polytechnic Institute Rio de Janeiro State University Petrobras Department of Stratigraphy and Paleontology Rio de Janeiro State University

Rock samples' TOc content is the best indicator of the organic matter in source rocks. The origin rock samples' analysis is used to calculate it manually by specialists. This method requires time and resources because it relies on samples from many well intervals in source rocks. Therefore, research has been done to aid this effort. Machine learning algorithms can estimate total organic carbon instead of well logs and stratigraphic studies. In light of these efforts, the current work present a study on automating the total organic carbon estimation using machine learning approaches improved by an evolutionary methodology to give the model flexibility and precision. Genetic algorithms, differential evolution, particle swarm optimization, grey wolf optimization, artificial bee colony, and evolution strategies were used to improve machine learning models to predict TOc. The six metaheuristics were integrated into four machine learning methods: extreme learning machine, elastic net linear model, linear support vector regression, and multivariate adaptive regression splines. core samples from the YuDong-Nan shale gas field, located in the Sichuan basin, were used to evaluate the hybrid strategy. The findings show that combining machine learning models with an evolutionary algorithms in a hybrid fashion produce flexible models that accurately predict TOc. The results show that, independent of the metaheuristic used to guide the model selection, optimized extreme learning machines attained the best performance scores according to six metrics. Such hybrid models can be used in exploratory geological research,particularly for unconventional oil and gas resources.

关键词： Total organic carbon Hybrid models Automated machine learning Evolutionary algorithms Geology

Recent advances on bismuth oxyhalides for photocatalytic cO_(2)reduction

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Journal of Environmental Sciences 2024年第6期140卷 183-203页

作者： Liangpang Xu Jimmy c.Yu Ying Wang Department of chemistry The Chinese University of Hong KongShatinNew TerritoriesHong Kong 999077China

Photocatalytic conversion of cO_(2)into fuels such as cO,cH_(4),and cH_(3)OH,is a promising approach for achieving carbon *** oxyhalides(BiOX,where X=cl,Br,and I)are appropriate photocatalysts for this purpose due to the merits of visible-light-active,efficient charge separation,and easy-to-modify crystal structure and surface *** practical applications,multiple strategies have been proposed to develop high-efficiency BiOX-based *** review summarizes the development of different approaches to prepare BiOX-based photocatalysts for efficient cO_(2)*** the review,the fundamentals of photocatalytic cO_(2)reduction are ***,several widely used modification methods for BiOX photocatalysts are systematacially discussed,including heterojunction construction,introducing oxygen vacancies(OVs),Bi-enrichment,heteroatom-doping,and morphology ***,the challenges and prospects in the design of future BiOX-based photocatalysis for efficient cO_(2)reduction are examined.

关键词： Bismuth oxyhalides Photocatalysis cO_(2)reduction Modification methods

Exercise immunology:Novel insights

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Journal of Sport and Health Science 2024年第3期13卷 277-279,I0001页

作者： David c.Nieman Human Performance Laboratory Appalachian State UniversityNorth Carolina Research CampusKannapolisNC 28081USA

The coronavirus disease 2019(cOVID-19)pandemic heightened worldwide attention on the influence of exercise on the immune *** were raised about whether regular moderate-to-vigorous physical activity(MVPA)could help prevent cOVID-19 or mitigate symptoms when *** MVPA bolster immunity among those most prone to cOVID-19 including the elderly,obese,and immunocompromised patients?Does regular MVPA dampen systemic inflammation,thereby lessening the cOVID-19 cytokine storm?

关键词： immunity inflammation thereby

Key Technologies and Prospects for Electric Vehicles Within Emerging Power Systems: Insights from Five Aspects

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cSEE Journal of Power and Energy Systems 2024年第2期10卷 439-447页

作者： Yalun Li Minggao Ouyang c.c.chan Xueliang Sun Yonghua Song Wei cai Yilin Xie Yuqiong Mao Department of Electrical Engineering and School of Vehicle and MobilityTsinghua UniversityBeijing 100084China School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China Department of Electrical and Electronic Engineering The University of Hong KongHong Kong 999077China Department of Mechanical and Materials Engineering University of Western OntarioLondonON N6A 3K7Canada State Key Laboratory of Internet of Things for Smart city University of MacaoTaipaMacao 999078China Department of Electrical Engineering Tsinghua UniversityBeijing 100084China School of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbin 150080China

The energy revolution requires coordination in energy consumption, supply, storage and institutional *** energy generation technologies, along with their associated costs, are already fully equipped for large-scale ***, energy storage remains a bottleneck, and solutions areneeded through the use of electric vehicles, which traditionallyplay the role of energy consumption in power systems. Toclarify the key technologies and institutions that support EVsas terminals for energy use, storage, and feedback, the cSEEJPES forum assembled renowned experts and scholars in relevantfields to deliver keynote reports and engage in discussions ontopics such as vehicle–grid integration technology, advancedsolid-state battery technology, high-performance electric motortechnology, and institutional innovation in the industry *** experts also provided prospects for energy storage andutilization technologies capable of decarbonizing new powersystems.

关键词： Electric vehicles engineering philosophy highpower density motor new power system solid state batteries vehicle grid integration.

HI in High Gas-phase Metallicity Dwarf Galaxy WISEA J230615.06+143927.9

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Research in Astronomy and Astrophysics 2024年第1期24卷 292-299页

作者： Yan Guo c.Sengupta T.c.Scott P.Lagos Y.Luo Purple Mountain Observatory Chinese Academy of SciencesNanjing 210023China School of Astronomy and Space Sciences University of Science and Technology of ChinaHefei 230026China Institute of Astrophysics and Space Sciences(IA Porto) Rua das Estrelas4150-762PortoPortugal

We present resolved Giant Metrewave Radio Telescope H I observations of the high gas-phase metallicity dwarf galaxy WISEA J230615.06+143927.9(z = 0.005)(hereafter J2306) and investigate whether it could be a Tidal Dwarf Galaxy(TDG) candidate. TDGs are observed to have higher metallicities than normal dwarfs. J2306 has an unusual combination of a blue g-r color of 0.23 mag, irregular optical morphology and high-metallicity(12 +log(O/H) = 8.68 ± 0.14), making it an interesting galaxy to study in more detail. We find J2306 to be an H I rich galaxy with a large extended, unperturbed rotating H I disk. Using our H I data we estimated its dynamical mass and found the galaxy to be dark matter(DM) dominated within its H I radius. The quantity of DM, inferred from its dynamical mass, appears to rule out J2306 as an evolved TDG. A wide area environment search reveals J2306 to be isolated from any larger galaxies which could have been the source of its high gas metallicity. Additionally, the H I morphology and kinematics of the galaxy show no indication of a recent merger to explain the *** detailed optical spectroscopic observations of J2306 might provide an answer to how a seemingly ordinary irregular dwarf galaxy achieved such a high level of metal enrichment.

关键词： galaxies:abundances galaxies:dwarf galaxies:irregular radio lines:galaxies radio lines:ISM

Multichannel coupling induced topological insulating phases with full multimerization

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Photonics Research 2024年第3期12卷 491-498页

作者： JUN LI YAPING YANG c-M.HU MOE Key Laboratory of Advanced Micro-Structured Materials School of Physics Science and EngineeringTongji UniversityShanghai 200092China Department of Physics and Astronomy University of ManitobaWinnipegManitoba R3T 2N2Canada

We propose and experimentally realize a class of quasi-one-dimensional topological lattices whose unit cells are constructed by coupled multiple identical resonators,with uniform hopping and inversion *** the presence of coupling-path-induced effective zero hopping within the unit cells,the systems are characterized by complete multimerization with degenerate-1 energy edge states for open boundary condition.

关键词： symmetry topological coupling