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Impact damage testing based on high-speed continuous water jet aircraft coatings

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Chinese Journal of Aeronautics 2024年第10期37卷 249-264页

作者： Minggong SHA Ying SUN Yutong LI Yiming LIU Gregory FEDOTENKOV lev RABINSKIY Arseniy BABAYTSEV Yulong LI School of Civil Aviation Northwestern Polytechnical UniversityXi’an 710072China Joint International Research Laboratory of Impact Dynamics and Engineering Application Xi’an 710072China Shaanxi Impact Dynamics and Engineering Application Laboratory Xi’an 710072China NPU Yangzi River Delta Research Institute Suzhou 215400China Moscow Aviation Institute(National Research University) Moscow 125993Russia

When an aircraft passes through a rainy area at high speed,the coating on the front edge of the fuselage will be continuously eroded by raindrops,causing the coating to wear,crack or even peel *** paper uses carbon fiber T300 material as the base material,and at the different impact speeds and impact numbers,water cutting equipment was used to simulate the erosion of the coating caused by the continuous impact of water *** damage morphology of samples at different damage stages was observed by digital microscope and Scanning Electron Microscope(SEM),and the damage evolution curve was established to analyze and reveal the damage behavior and damage mechanism of rain *** results show that the degree of damage experienced an increasing trend with the increase of impact numbers and speed,until circular peel damage was formed;no damage occurred during the incubation period,and the curvature of the damage evolution curve increased significantly after the expansion period and eventually showed a stable expansion *** mechanical properties of the coating material were the main influencing factors of its rain corrosion ***,the axially symmetric unsteady contact problem of droplets impacting the surface of a solid deformable body was *** the contact area was determined based on the iterative algorithm boundary positioning method.A mathematical model and closed mathematical formula describing the unsteady interaction between a droplet and a solid deformable obstacle were proposed.

关键词： Rain erosion damage Liquid-solid impact Multiple jets Composite materials Impact dynamics

Phase transitions and degradation/oxidation mechanisms in lead-free CsSnI_(3)halide perovskites

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Clean Energy 2024年第3期8卷 109-115页

作者： Alexandra Ivanova Margarita Golikova lev Luchnikov Pavel Gostishchev Igor Shetinin Victor Voronov Danila Saranin Vladimir Khovaylo National University of Science and Technology MISIS(NUST MISIS) Leninsky av.4Moscow119049Russia Belgorod State University Pobedy st.85Belgorod308015Russia

Halide perovskites possess ultra-low thermal conductivity and show high potential for thermoelectric *** chemical properties and molecular structure of halide perovskite materials are not completely stable under ambient conditions,which hinders their use in thermoelectric *** in the properties of bulk halide perovskite thermoelectrics are accompanied by partial phase transitions and surface oxidation *** this paper,we conducted a comprehensive study of the transport and structural properties of CsSnI_(3),which were pristine by vacuum melting followed by spark plasma *** research results on the electrical transport of these materials revealed that exposure to an inert atmosphere does not deteriorate stability and the properties of the materials remain ***,prolonged exposure to air leads to a significant degradation of the electrical transport *** to thin-film samples,the shift to the double perovskite structure from the perovskite one is limited to a specific surface *** change significantly influences the electrical transport of the material while maintaining the essential properties of both perovskite types.

关键词： halide perovskites degradation oxidation transport properties surface

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Cavity continuum

Photonics Research 2024年第3期12卷 391-398页

作者： FAN CHENG VLADIMIR SHUVAYEV MARK DOUVIDZON lev DEYCH TAL CARMON School of Electrical Engineering Tel Aviv UniversityTel Aviv 6997801Israel Physics Department Queens College of CUNYFlushingQueensNew York 11367USA Solid State Institute Technion-Israel Institute of TechnologyHaifa 3200003Israel The Graduate Center of CUNY New YorkNew York 10016USA

We experimentally demonstrate and numerically analyze large arrays of whispering gallery *** fluorescent mapping,we measure the spatial distribution of the cavity ensemble’s resonances,revealing that light reaches distant resonators in various ways,including while passing through dark gaps,resonator groups,or resonator *** spatially decays exponentially in the *** practically infinite periodic array of resonators,with a quality factor(Q)exceeding 107,might impact a new type of photonic ensembles for nonlinear optics and lasers using our cavity continuum that is distributed,while having high-Q resonators as unit cells.

关键词： resonator cavity ensemble

急性缺血性卒中影像学检查的建议--美国心脏协会的科学声明(下)

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中国脑血管病杂志 2010年第3期7卷 274-280页

作者： Latchaw RE Alberts MJ lev mh 蒋丽丹美国心脏协会心血管放射介入委员会卒中委员会外周血管病多学科委员会首都医科大学宣武医院介入放射诊断治疗科北京100053

3．3．1．4SPECT在急性卒中中的应用：对于非溶栓患者，很多研究证实，HMPAO-99mTcSPECT可检查急性卒中症状相关的低灌注区。有两项双盲对照的前瞻性研究显示，SPECT对急性卒中灌注异常的敏感性为61％～74％，特异性为88％～98％（证据... 详细信息

3．3．1．4SPECT在急性卒中中的应用：对于非溶栓患者，很多研究证实，HMPAO-99mTcSPECT可检查急性卒中症状相关的低灌注区。有两项双盲对照的前瞻性研究显示，SPECT对急性卒中灌注异常的敏感性为61％～74％，特异性为88％～98％（证据级别：A级）。图像所示异常与梗死灶大小、神经功能缺损严重程度及未治疗患者的预后有关，

关键词：卒中脑缺血诊断显像体层摄影扫描仪 x线计算机磁共振成像脑血管造影术规范指南

急性缺血性卒中影像学检查的建议--美国心脏协会的科学声明(中)

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中国脑血管病杂志 2010年第4期7卷 220-224页

2．3核磁共振血管成像（MRA）2．3．1背景和方法：在头部MRI检查中常结合MRA，用于急性卒中患者病情评估以指导治疗决策的制定^[19]。日前，有几种不同的MRA技术用于脑血管成像，包括二维时间飞跃（timeof-flight，TOF）序列、三维TOF... 详细信息

2．3核磁共振血管成像（MRA）2．3．1背景和方法：在头部MRI检查中常结合MRA，用于急性卒中患者病情评估以指导治疗决策的制定^[19]。日前，有几种不同的MRA技术用于脑血管成像，包括二维时间飞跃（timeof-flight，TOF）序列、三维TOF序列、

关键词：卒中脑缺血诊断显像体层摄影扫描仪 X线计算机磁共振成像脑血管造影术规范指南

Catalytically altering the redox pathway of sulfur in propylene carbonate electrolyte using dual-nitrogen/oxygen-containing carbon

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Chinese Journal of Catalysis 2024年第8期63卷 224-233页

作者： Linghui Yu Heng Zhang Luyuan Paul Wang Samuel Jun Hoong Ong Shibo Xi Bo Chen Rui Guo Ting Wang Yonghua Du Wei Chen Ovadia lev Zhichuan J.Xu School of Chemistry and Chemical Engineering Wuhan Textile UniversityWuhan 430200HubeiChina School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Hubei Key Laboratory of Biomass Fibers&Eco-Dyeing&Finishing Wuhan Textile UniversityWuhan 430200HubeiChina Institute of Sustainability for Chemicals Energy and Environment(ISCE2)Agency for ScienceTechnology and Research in Singapore(A*STAR)1 Pesek RoadJurong Island 627833Singapore Department of Chemistry National University of SingaporeSingapore 117543Singapore College of the Environment&Ecology Xiamen UniversityXiamen 361102FujianChina National Synchrotron Light Source II Brookhaven National LaboratoryUptonNY 11973USA The Institute of Chemistry The Hebrew University of JerusalemJerusalem 9190401Israel Singapore-HUJ Alliance for Research and Enterprise NEW-CREATE Phase IICampus for Research Excellence and Technological Enterprise(CREATE)Singapore138602Singapore Energy Research Institute@NTU ERI@NInterdisciplinary Graduate SchoolNanyang Technological UniversitySingapore 639798Singapore

Carbonate electrolytes are one of the most desirable electrolytes for high-energy lithium-sulfur batteries(LSBs)because of their successful implementation in commercial Li-ion *** low-polysulfide-solubility feature of some carbonate solvents also makes them very promising for overcoming the shuttle effects of ***,regular sulfur electrodes experience undesired electrochemical mechanisms in carbonate electrolytes due to side *** this study,we report a catalytic redox mechanism of sulfur in propylene carbonate(PC)electrolyte based on a compari-son *** catalytic mechanism is characterized by the interactions between polysulfides and dual N/O functional groups on the host carbon,which largely prevents side reactions between pol-ysulfides and the carbonate *** a mechanism coupled with the low-polysulfide-solubility feature leads to stable cycling of LSBs in PC *** dual N/O functional groups are identified via a density functional theory *** work provides an alternative route for enabling LSBs in carbonate electrolytes.

关键词： Energy storage Lithium-sulfur battery Catalytic redox reaction Porous carbon Carbonate electrolyte

AI图像与生成媒介:关于当下革命的若干笔记

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北京电影学院学报 2024年第9期 4-13页

作者： [美]列夫·马诺维奇张昊博(译) 美国纽约市立大学研究生中心河北美术学院影视艺术学院

近年来,生成式人工智能(AI)技术在视觉媒介领域的广泛应用,引发了学界从本体论、认识论与方法论等多个维度对艺术存在的重新审视。生成式AI利用深度神经网络模型在大型数据集上进行训练,并根据用户输入的指令自动生成美学风格多样化的... 详细信息

近年来,生成式人工智能(AI)技术在视觉媒介领域的广泛应用,引发了学界从本体论、认识论与方法论等多个维度对艺术存在的重新审视。生成式AI利用深度神经网络模型在大型数据集上进行训练,并根据用户输入的指令自动生成美学风格多样化的“艺术作品”。然而,这一自动机制在丰富人类艺术创作与表达的同时也引发了一系列文化域的关键问题:生成式AI是对数据集中的艺术作品的简单复制或模仿,还是复杂创新与超越?生成式AI与人类的艺术创造力之间是否有相似之处?这些问题亟待深入探讨。本文回顾了AI、视觉媒介与艺术的发展历程,揭示了其中存在的接续性关系,旨在分析生成式AI在当代视觉媒介、艺术与文化当中的引发的艺术革命。

关键词：生成式AI AI 图像视觉媒介生成媒介

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腐植酸包膜尿素减少土壤氮素损失的研究

腐植酸 2024年第5期 50-58页

作者： Konstantin Korsakov Alexey Stepanov lev Pozdnyakov Olga Yakimenko 刘晓蕾寇太记俄罗斯莫斯科生命力量集团有限责任公司俄罗斯莫斯科国立大学土壤科学系河南科技大学农学院

通过室内模型试验，以普通尿素（U）、腐植酸包膜尿素（U-HA）和脲酶抑制剂N-（正丁基）硫磷三酰胺处理尿素（U-UI）为研究对象，研究了3种尿素肥料对土壤氮素转化过程的影响。更正研究了尿素肥料对土壤化学（水浸提N-NH4和N-NO3含量）... 详细信息

通过室内模型试验，以普通尿素（U）、腐植酸包膜尿素（U-HA）和脲酶抑制剂N-（正丁基）硫磷三酰胺处理尿素（U-UI）为研究对象，研究了3种尿素肥料对土壤氮素转化过程的影响。更正研究了尿素肥料对土壤化学（水浸提N-NH4和N-NO3含量）和微生物特性（N2O实际和潜在排放速率、基础呼吸和底物诱导的呼吸、微生物生物量碳、乙烯排放速率）的影响，旨在验证：（i）腐植酸包膜尿素是否具有减少土壤氮素损失的能力；（ii）与合成脲酶抑制剂相比，它是如何影响土壤生物活性的。结果表明，U-HA在减少土壤氮素损失方面具有与U相当的优势，使土壤N-NH4含量增加了35%，硝酸盐含量减少了9%，N2O排放减少了50%。U-HA使土壤基础呼吸提高了10%，土壤微生物群落比活性提高了7%，提供了最高的代谢熵qCO2。与U-UI相比，U-HA主要表现为介于U-UI和U之间的效果。考虑到腐植酸原料成本低，U-HA可以被认为是减少土壤氮素损失的有前景的工具。

关键词：腐殖质腐植酸钾风化褐煤尿素无机养分氨化作用反硝化作用脲酶抑制剂

Factorizations of Finite Groups and Related Topics

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Algebra Colloquium 2020年第1期27卷 149-180页

作者： lev Kazarin Department of Mathematics Yaroslavl State UniversityRussia

This is a survey on the recent progress in the theory of finite groups with factorizations and around it,done by the author and his coauthors,and this has no pretensions to cover all topics in this wide area of *** particular,we only touch the great consequences of the fundamental paper of Liebeck,Praeger and Saxl on maximal factorizations of almost simple finite groups for the theory of groups with *** each case the reader can find additional references at the end of Section *** of the methods of investigation can be used to obtain information about finite groups in general,nilpotent algebras and related nearrings.

关键词： finite groups products of groups conjugacy classes Sylow subgroups Lie type groups factorizations