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扩散加权MRI鉴别卵巢交界性与恶性上皮性肿瘤:病理对照研究

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国际医学放射学杂志 2014年第6期 600-601页

作者： S.H.Zhao j.w.qiang G.F.Zhang F.H.Ma S.Q.Cai H.M.Li 成杰 Department of Radiology Jinshan HospitalFudan University

摘要目的探讨MR扩散加权成像(DwI)鉴别卵巢交界性与恶性上皮性肿瘤。方法回顾性研究共纳入48例病人共60个交界性上皮性卵巢肿瘤(BEOT),54例病人共65个

关键词：恶性上皮性肿瘤交界性卵巢性腺扩散加权 MRI

Multicolored Bipartite Ramsey Numbers of Large Cycles

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 347-357页

作者： Shao-qiang LIU Yue-jian PENG College of Mathematics and Statistics Hanshan Normal UniversityChaozhou 521041China School of Mathematics Hunan UniversityChangsha 410082China

For an integer r≥2 and bipartite graphs Hi,where 1≤i≤r,the bipartite Ramsey number br(H1,H2,…,Hr)is the minimum integer N such that any r-edge coloring of the complete bipartite graph KN;N contains a monochromatic subgraph isomorphic to Hi in color i for some 1≤i≤*** show that if r≥3;α1,α2>0,αj+2≥[(j+2)!-1]Σi=1^(j+1)α1 for j=1,2…r-2,then br(C2[α1n],C2[α2n],…,C2[αrn]=(Σ=j=1^(r)a j+o(1))n.

关键词： ramsey number bipartite ramsey number regularity lemma

Influence of Vanes and Blades on Ingress in Axial Rim Seal for Turbine Stages

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journal of Thermal Science 2024年第3期33卷 833-846页

作者： REN Ran DU qiang LIU Guang ZENG Yanlian XIE Lei Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing100190China National Key Laboratory of Science and Technology on Advanced Light-duty Gas-turbine Beijing100190China School of Aeronautics and Astronautics University of Chinese Academy of SciencesBeijing100190China

Hot gas ingestion refers to the phenomenon of mainstream hot gas flowing into the space cavity of a turbine *** studies have found that mainstream annulus pressure distribution plays an important role in hot gas ingestion,but due to its complexity,the mechanism of the interaction between mainstream flow and hot gas ingestion remains *** paper adopts the URANS method,and three sealing flow rates are considered,named C_(w)=0,C_(w)=500,and C_(w)=*** time-averaged annulus pressure distribution shows that an increase in the sealing flow decreases the pressure value,and the effects of the sealing flow on the pressure distribution of the leading edge of the blade are much more influential than that of the trailing edge of the *** unsteady pressure time-space distribution in the annulus indicates that a time-space tilted distribution of pressure at the rim exits when the sealing flow *** phenomenon is mainly due to the strong feedback mechanism of the sealing flow to the annulus pressure field.A comparison of the pressure and mean radial velocity distribution of the mainstream shows that the ingestion mainly occurs on the blade side,where the pressure is lower than on the vane *** flow characteristics at the wheel rim are analyzed with a sealing flow rate C_(w)=5000,and under these conditions,both pressure-induced ingestion and ingestion caused by a passage vortex can be *** three-dimensional and inertial effects of the mainstream at the wheel rim lead to the generation of separation vortices on the blade side,and the presence of separation vortices leads to ingestion along the blade *** the same time,pressure on the blade side will cause the fluid to have a radial inward flow tendency,which will promote the formation of separation vortices,leading to more serious ingestion in the high-pressure region on the blade *** blade pressure field can be more significant than the vane trailing pressure field in the rim sea

关键词： separation vortex unsteady rim seal the effect of blade on ingestion

Mechanical property of cylindrical sandwich shell with gradient core of entangled wire mesh

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Defence Technology（防务技术） 2024年第1期31卷 510-522页

作者： Xin Xue Chao Zheng Fu-qiang Lai Xue-qian wu Institute of Metal-rubber&Vibration Noise School of Mechanical Engineering and AutomationFuzhou UniversityFuzhou350116China Fujian Metallurgical Industry Design Institute Fuzhou350116China

To explore the wide-frequency damping and vibration-attenuation performances in the application of aerospace components,the cylindrical sandwich shell structure with a gradient core of entangled wire mesh was proposed in this ***,the gradient cores of entangled wire mesh in the axial and radial directions were prepared by using an in-house Numerical Control weaving machine,and the metallurgical connection between skin sheets and the gradient core was performed using vacuum ***,to investigate the mechanical properties of cylindrical sandwich shells with axial or radial gradient cores,quasi-static and dynamic mechanical experiments were carried *** primary evaluations of mechanical properties include secant stiffness,natural frequency,Specific Energy Absorption(SEA),vibration acceleration level,and so *** results suggest that the vibration-attenuation performance of the sandwich shell is remarkable when the high-density core layer is at the end of the shell or abuts the inner *** axial gradient material has almost no influence on the vibration frequencies of the shell,whereas the vibration frequencies increase dramatically when the high-density core layer approaches the ***,compared to the conventional sandwich shells,the proposed functional grading cylindrical sandwich shell exhibits more potential in mass reduction,stiffness designing,and energy dissipation.

关键词： Entangled wire mesh Gradient cylindrical sandwich shell Vacuum brazing Secant stiffness Damping

Mechanocatalysis of CO to CO_(2)on TiO_(2)surface controlled at atomic scale

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Nano Research 2024年第7期17卷 5826-5834页

作者： Yuuki Adachi Robert Turanský ján Brndiar Kamil Tokár qiang Zhu Huan Fei wen Yasuhiro Sugawara IvanŠtich Yan jun Li Department of Applied Physics Osaka University2-1 YamadaokaSuitaOsaka 565-0871Japan Institute of Physics Slovak Academy of SciencesBratislava 84511Slovakia Institute of Informatics Slovak Academy of SciencesBratislava 84507Slovakia Faculty of Natural Sciences University of Ss.Cyril and MethodiusTrnava 91701Slovakia Key Laboratory of Instrumentation Science and Dynamic Measurement School of Instrument and ElectronicsNorth University of ChinaTaiyuan 030051China

The common ways to activate a chemical reaction are by heat,electric current,or ***,mechanochemistry,where the chemical reaction is activated by applied mechanical force,is less common and only poorly understood at the atomic *** we report a tip-induced activation of chemical reaction of carbon monoxide to dioxide on oxidized rutile TiO_(2)(110)*** activation is studied by atomic force microscopy,Kelvin probe force microscopy under ultrahigh-vacuum and liquid nitrogen temperature conditions,and density functional theory(DFT)*** reaction is inferred from hysteretic behavior of frequency shift signal further supported by vector force mapping of vertical and lateral forces needed to trigger the chemical reaction with torque motion of carbon monoxide towards an oxygen *** reaction is found to proceed stochastically at very small tip-sample ***,the local contact potential difference reveals the atomic-scale charge redistribution in the reactants required to unlock the *** results open up new insights into the mechanochemistry on metal oxide surfaces at the atomic scale.

关键词： atomic resolution mechanochemistry atomic force microscopy Kelvin probe force microscopy density functional theory(DFT)simulation CO oxidation catalysis rutile TiO_(2)surface

Recent advances in graphene-based phase change composites for thermal energy storage and management

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Nano Materials Science 2024年第2期6卷 115-138页

作者： qiang Zhu Pin jin Ong Si Hui Angela Goh Reuben j.Yeo Suxi wang Zhiyuan Liu Xian jun Loh Institute of Materials Research and Engineering A*STAR(Agency for ScienceTechnology and Research)2 Fusionopolis WayInnovis#08-03138634Singapore Institute of Sustainability for Chemicals Energy and EnvironmentA*STAR(Agency for ScienceTechnology and Research)1 Pesek RoadJurong Island627833Singapore School of Chemistry Chemical Engineering and BiotechnologyNanyang Technological University21 Nanyang Link637371Singapore Shenzhen Institutes of Advanced Technology(SIAT) Chinese Academy of Sciences(CAS)1068 Xueyuan AvenueShenzhen518055China Department of Material Science and Engineering National University of Singapore9 Engineering Drive 1#03-09 EA117575Singapore

Energy storage and conservation are receiving increased attention due to rising global energy ***,the development of energy storage materials is *** energy storage(TES)systems based on phase change materials(PCMs)have increased in prominence over the past two decades,not only because of their outstanding heat storage capacities but also their superior thermal energy regulation ***,issues such as leakage and low thermal conductivity limit their applicability in a variety of ***-based materials such as graphene and its derivatives can be utilized to surmount these *** study examines the recent advancements in graphene-based phase change composites(PCCs),where graphene-based nanostructures such as graphene,graphene oxide(GO),functionalized graphene/GO,and graphene aerogel(GA)are incorporated into PCMs to substantially enhance their shape stability and thermal conductivity that could be translated to better storage capacity,durability,and temperature response,thus boosting their attractiveness for TES *** addition,the applications of these graphene-based PCCs in various TES disciplines,such as energy conservation in buildings,solar utilization,and battery thermal management,are discussed and summarized.

关键词： Phase change material Nanocomposites Solar energy Sustainable energy Thermo-regulation

Heteroatom anchors Fe-Mn dual-atom catalysts with bi-functional oxygen catalytic activity for low-temperature rechargeable flexible Zn-air batteries

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journal of Energy Chemistry 2024年第3期90卷 610-620,I0014页

作者： Yuting He Hongtao Li Yi wang Yufei jia Yongning Liu qiang Tan State Key Laboratory for Mechanical Behaviour of Materials School of Materials Science&EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina

M-N-C(M=Fe,Co,Ni,etc.) catalyst owns high catalytic activity in the oxygen catalytic reaction which is the most likely to replace the Pt-based *** it is still a challenge to further increase the active site *** article constructs the high-efficiency FeMn-N/S-C-1000 catalyst to realize ORR/OER bifunctional catalysis by hetero-atom,bimetal(Fe,Mn) doped simultaneously *** evaluated it as bi-functional electro-catalysts,FeMn-N/S-C-1000 exhibits excellent catalytic activity(E_(1/2)=0.924 V,E_(j=10)=1.617 V) in alkaline media,outperforms conventional Pt/C,RuO_(2) and most non-precious-metal catalysts reported recently,Such outstanding performance is owing to N,S co-coordinated with metal to form multi-types of single atom,dual atom active sites to carry out ***,nitrite poison test provides the proof that the active sites of FeMn-N/S-C are more than that of single-atom catalysts to promote catalytic reactions *** better understand the local structure of Fe and Mn active sites,XAS and DFT were employed to reveal that FeMn-N_5/S-C site plays the key role during ***,the FeMn-N/S-C-1000 based low-temperature rechargeable flexible Zn-air also exhibits superior discharge performance and extraordinary durability at-40℃.This work will provide a new idea to design diatomic catalysts applied in low-temperature rechargeable batteries.

关键词： Fe Mn-N/S-C-1000 ORR OER Rechargeable flexible Zn-air batteries

An anti-icing scaling method for wind tunnel tests of aircraft thermal ice protection system

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Chinese journal of Aeronautics 2024年第6期37卷 1-6页

作者： Yu LIU qiang wANG Xian YI Ningli CHEN jinghao REN weihao LI Key Laboratory of Icing and Anti/de-icing China Aerodynamics Research and Development CenterMianyang 621000China State Key Laboratory of Aerodynamics Mianyang 621000China

The efficiency of the aircraft Ice Protection Systems(IPSs)needs to be verified through icing wind tunnel ***,the scaling method for testing the IPSs has not been systematically established yet,and further research is *** the present study,a scaling method specifically designed for thermal IPSs was derived from the governing equation of thin water *** scaling parameters were adopted to address the heat and mass transfer involved in the thermal anti-icing *** method validation,icing wind tunnel tests were conducted using a jet engine nacelle model equipped with a bleed air *** non-dimensional surface temperature and runback ice closely matched for both the reference and scaled *** validation confirms that the scaling method is capable of achieving the similarity of surface temperature and the runback ice *** anti-icing scaling method can serve as an important supplement to the existing icing similarity theory.

关键词： Scaling method Ice protection system water film Anti-icing test Icing wind tunnel

Emergent symmetry in quantum phase transition:From deconfined quantum critical point to gapless quantum spin liquid

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Science Bulletin 2024年第2期69卷 190-196页

作者： wen-Yuan Liu Shou-Shu Gong wei-qiang Chen Zheng-Cheng Gu Department of Physics The Chinese University of Hong KongHong KongChina Division of Chemistry and Chemical Engineering California Institute of TechnologyPasadena CA 91125USA School of Physical Sciences Great Bay UniversityDongguan 523000China Great Bay Institute for Advanced Study Dongguan 523000China Department of Physics and Shenzhen Institute for Quantum Science and Engineering Southern University of Science and TechnologyShenzhen 518055China Shenzhen Key Laboratory of Advanced Quantum Functional Materials and Devices Southern University of Science and TechnologyShenzhen 518055China

The emergence of exotic quantum phenomena in frustrated magnets is rapidly driving the development of quantum many-body physics,raising fundamental questions on the nature of quantum phase *** we unveil the behaviour of emergent symmetry involving two extraordinarily representative phenomena,i.e.,the deconfined quantum critical point(DQCP)and the quantum spin liquid(QSL)*** large-scale tensor network simulations,we study a spatially anisotropic spin-1/2 square-lattice frustrated antiferromagnetic(AFM)model,namely the j1x-j1y-j2 model,which contains anisotropic nearestneighbor couplings j1x,j1y and the next nearest neighbor coupling *** small j1y/j1x,by tuning j2,a direct continuous transition between the AFM and valence bond solid phase is *** growing j1y/j1x,a gapless QSL phase gradually emerges between the AFM and VBS *** observe an emergent O(4)symmetry along the AFM–VBS transition line,which is consistent with the prediction of DQCP *** surprisingly,we find that such an emergent O(4)symmetry holds for the whole QSL–VBS transition line as *** findings reveal the intrinsic relationship between the QSL and DQCP from categorical symmetry point of view,and strongly constrain the quantum field theory description of the QSL *** phase diagram and critical exponents presented in this paper are of direct relevance to future experiments on frustrated magnets and cold atom systems.

关键词： Tensor network Quantum phase transition Emergent symmetry Quantum spin liquid Deconfined quantum critical point Anisotropic