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Burning Numbers of Barbells

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Acta Mathematicae Applicatae Sinica 2024年第2期40卷 526-538页

作者： Hui-qing LIU Rui-ting ZHANG Xiao-lan HU Hubei Key Laboratory of Applied Mathematics&Faculty of Mathematics and Statistic Hubei UniversityWuhan 430062China Hubei Key Laboratory of Mathematical Sciences&School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China

Motivated by a discrete-time process intended to measure the speed of the spread of contagion in a graph,the burning number b(G)of a graph G,is defined as the smallest integer k for which there are vertices x1,…xk such that for every vertex u of G,there exists i∈{1,…k}with dG(u,xi)≤k−i,and dG(xi,xj)≥j−i for any 1≤ij≤*** graph burning problem has been shown to be NP-complete even for some acyclic graphs with maximum degree *** this paper,we determine the burning numbers of all short barbells and long barbells,respectively.

关键词： burning number short/long barbell isometric subtree cycle

Polymer transfer film formation from cryogenic to elevated temperatures

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Friction 2024年第9期12卷 2018-2032页

作者： Kian BASHANDEH Vasilis TSIGKIS Ahmad AMIRI Pixiang lan Andreas A.POLYCARPOU j.Mike Walker’66 Department of Mechanical Engineering Texas A&M UniversityCollege StationTexas 77843USA ATSP Innovations Inc.HoustonTexas 77055USA Russell School of Chemical Engineering The University of TulsaTulsaOklahoma 74104USA Department of Mechanical Engineering The University of TulsaTulsaOklahoma 74104USA

This study reports on the tribological performance of aromatic thermosetting co-polyester(ATSP)and polyether ether ketone(PEEK)-based polymer composite coatings mixed with PTFE *** coatings were tested across a wide temperature range from−180 to 110℃ to simulate the environmental temperatures on Titan,Moon,and Mars,which are of particular interest for NASA’s future exploratory *** experimental setup was developed to conduct the pin-on-disk experiments under dry sliding conditions and extreme temperature and contact *** film formation and its characteristics were found to play significant roles in the tribological performance,and the characteristics of the film were *** XPS and SEM analysis indicated the increase of the PTFE content in the transfer film as the temperature decreased to cryogenic *** coefficient of friction did not follow a linear trend with temperature and was minimum at 110℃ and maximum at−180℃.ATSP coating showed superior performance with lower friction and unmeasurable wear at all temperatures,whereas PEEK coating exhibited maximum wear at 25℃ followed by−180,and 110℃.

关键词： transfer film cryogenic high temperature tribology space tribology polymer coating

Emerging mechanisms and implications of c GAS-STING signaling in cancer immunotherapy strategies

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Cancer Biology & Medicine 2024年第1期21卷 45-64页

作者： jiawen Zhang Sihui Yu Qiao Peng Ping Wang lan Fang Tongji University Cancer Center Shanghai Tenth People’s HospitalSchool of MedicineTongji UniversityShanghai 200072China Reproductive Medicine Center Department of Obstetrics and GynecologyShanghai General HospitalShanghai Jiao Tong University School of MedicineShanghai 201620China Department of Obstetrics and Gynecology Zhongshan HospitalFudan UniversityShanghai 200032China

The intricate interplay between the human immune system and cancer development underscores the central role of immunotherapy in cancer *** this landscape,the innate immune system,a critical sentinel protecting against tumor incursion,is a key *** cyclic GMP-AMP synthase(c GAS)and stimulator of interferon genes(STING)pathway has been found to be a linchpin of innate immunity:activation of this signaling pathway orchestrates the production of type I interferon(IFN-α/β),thus fostering the maturation,differentiation,and mobilization of immune effectors in the tumor ***,STING activation facilitates the release and presentation of tumor antigens,and therefore is an attractive target for cancer *** strategies to activate the STING pathway,including use of pharmacological agonists,have made substantial advancements,particularly when combined with immune checkpoint *** approaches have shown promise in preclinical and clinical settings,by enhancing patient survival *** review describes the evolving understanding of the c GAS-STING pathway's involvement in tumor biology and ***,this review explores classical and non-classical STING agonists,providing insights into their mechanisms of action and potential for optimizing immunotherapy *** challenges and complexities,the c GAS-STING pathway,a promising avenue for enhancing cancer treatment efficacy,has the potential to revolutionize patient outcomes.

关键词： cGAS-STING pathway type I interferon cyclic dinucleotide STING agonist cancer immunotherapy

Fabrication of Molecularly Imprinted Electrospun Nanofibers with Mono-amidoxime Functional Ligand for Efficient Decontamination of Toxic Organophosphates

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Chinese journal of Polymer Science 2024年第4期42卷 446-456页

作者： lan Wang Peng jiang Ya-Lin Niu jun-Peng Cao Tian-Ying Guo Key Laboratory of Functional Polymer Materials Ministry of EducationInstitute of Polymer ChemistryCollege of Chemistry and Frontier Science Center for the Creation of New Organic SubstancesNankai UniversityTianjin300071China

There is an urgent imperative to discover practical and efficacious artificial catalysts for the expeditious decontamination of toxic organophosphates. Herein, we propose a novel molecularly imprinted approach utilizing electrospun fiber scaffolds. Specifically, an amidoxime-based functional polymer (PMAOX) has been synthesized, which contains amidoxime groups that can act as nucleophiles and ligands for the formation of catalytic active sites. This polymer was blended with polyacrylonitrile (PAN), a well-processable material, to prepare a nanofiber mat using electrospinning techniques. Then, the amidoxime side groups on fiber surface were further cross-linked after the molecular coordination of templates to complete the molecularly imprinting process. This approach can not only enhance the content of functional molecularly imprinted polymers without affecting structural stability, but also combines surface MI technology to fully expose and leverage the advantages of active sites. The as prepared molecularly imprinted electrospun nanofibers MIF-Zn-PMAOX/PAN-6/4 catalyzes the degradation of paraoxon with a half-life of 32 min, and MIF-Ag-PMAOX/PAN catalyzes the degradation of parathion with a half-life of 18 min. The maximum catalytic rate evidence rate enhancements nearly 3700-fold of the self-hydrolysis. Thus, the mono-amidoxime based molecularly imprinted fibers demonstrate the versatility and superiority as self-detoxifying for organophosphates.

关键词： Organophosphateshydrolysis Electrospinning Molecular imprinting

Defect detection and repair algorithm for structures generated by topology optimization based on 3D hierarchical fully convolutional network

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Biomimetic Intelligence & Robotics 2024年第2期4卷 24-31页

作者： Zhiyu Wan Hai lan Sichao Lin Houde Dai School of Advanced Manufacturing Fuzhou UniversityJinjiang 362251China Quanzhou Institute of Equipment Manufacturing Haixi InstitutesChinese Academy of SciencesJinjiang 362216China Fujian Key Laboratory of Special Intelligent Equipment Safety Measurement and Control Fujian Special Equipment Inspection and Research InstituteFuzhou 350008China

Customized 3D-printed structural parts are widely used in surgical *** satisfy the mechanical properties and kinematic functions of these structural parts,a topology optimization technique is adopted to obtain the optimal structural layout while meeting the constraints and ***,topology optimization currently faces some practical challenges that must be addressed,such as ensuring that structures do not have significant defects when converted to additive manufacturing *** address this problem,we designed a 3D hierarchical fully convolutional network(FCN)to predict the precise position of the defective *** on the prediction results,an effective repair strategy is adopted to repair the defective structure.A series of experiments is conducted to demonstrate the effectiveness of our *** to the 2D fully convolutional network and the rule-based detection method,our approach can accurately capture most defect structures and achieve 89.88%precision and 95.59%***,we investigate the impact of different ways to increase the receptive field of our model,as well as the trade-off between different defect-repairing *** results of the experiment demonstrate that the hierarchical structure,which increases the receptive field,can substantially improve the defect detection *** the best of our knowledge,this paper is the first to investigate 3D defect prediction and repair for topology optimization in conjunction with deep learning algorithms,providing practical tools and new perspectives for the subsequent development of topology optimization techniques.

关键词： Topology optimization Additive manufacturing Deep learning 3D semantic segmentation Defect detection

Microstructure Evolution and Nanomechanical Behavior of Micro-Area in Molten Pool of Selective Laser Melting(CoCrNi)_(82)Al_(9)Ti_(9)High-Entropy Alloy

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 1019-1033页

作者： Hong-Wei Zhang Li-Wei lan Zhe-Yu Yang Chang-Chun Li Wen-Xian Wang College of Materials Science and Engineering Taiyuan University of TechnologyTaiyuan030024China Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced MaterialsTaiyuan University of TechnologyTaiyuan030024China Shanxi-Zhejiang University New Materials and Chemical Research Institute Taiyuan030032China

In this work,the phase evolution mechanism and nanomechanical properties of(CoCrNi))(82)Al_(9)Ti_(9)high-entropy alloy(HEA)prepared by selective laser melting(SLM)in the molten pool were *** HEA contains multiple primary elements and undergoes high-temperature gradient and rapid cooling during *** leads to significant inhomogeneity of nano-scale microstructure characteristics and instability of *** optimizing process parameters,the microstructure evolution at the optimal parameter volume energy density of 440 j/mm^(3)was studied.A phase transition from BCC to FCC occurred in the melt *** the micro-area of the melt pool results in a temperature rise and the combustion-induced loss of Al ***,the Ni element content increases significantly outside the melt *** process enhances the phase stability of FCC and facilitates phase ***,rapid cooling leads to the formation of distinctive ultrafine equiaxial crystals inside the melt pool,accompanied by the generation of intracrystalline needle-like nano-scale *** the melt pool,the accumulation of energy results in the formation of coarse ***,the nano-hardness inside the molten pool is remarkably high at 11.79 GPa,while the outside the molten pool is reduced to 9.58 *** the fracture toughness outside the melt pool also *** with inside the melt pool,the residual stress outside the melt pool changed from compressive to tensile stress and decreased from 603.28 to 322.84 MPa.

关键词： High-entropy alloys Selective laser melting Microstructure evolution Nanoindentation

Free-moving-state microscopic imaging of cerebral oxygenation and hemodynamics with a photoacoustic fiberscope

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Light(Science & Applications) 2024年第1期13卷 33-46页

作者： Xiaoxuan Zhong Yizhi Liang Xiaoyu Wang Haoying lan Xue Bai Long jin Bai-Ou Guan Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications Institute of Photonics TechnologyJinan UniversityGuangzhou510632China

We report the development of a head-mounted photoacoustic fiberscope for cerebral imaging in a freely behaving *** 4.5-gram imaging probe has a 9-µm lateral resolution and 0.2-Hz frame rate over a 1.2-mm wide *** probe can continuously monitor cerebral oxygenation and hemodynamic responses at single-vessel resolution,showing significantly different cerebrovascular responses to external stimuli under anesthesia and in the freely moving *** example,when subjected to high-concentration CO_(2) respiration,enhanced oxygenation to compensate for hypercapnia can be visualized due to cerebral regulation in the freely moving *** studies exhibit significantly weakened compensation capabilities in obese *** new imaging modality can be used for investigating both normal and pathological cerebrovascular functions and shows great promise for studying cerebral activity,disorders and their treatments.

关键词： cerebral anesthesia moving

Numerical Simulation of the Mechanical Stirring Process in a Tannin-Based Foaming Precursor Resin

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Fluid Dynamics & Materials Processing 2024年第10期20卷 2219-2234页

作者： lan Huang Wenbin Yuan Hisham Essawy Xiaojian Zhou Xinyi Chen Yunnan Provincial Key Laboratory of Wood Adhesives and Glued Products Southwest Forestry UniversityKunming650224China Department of Polymers and Pigments National Research CentreCairo12622Egypt Key Laboratory for Forest Resources Conservation and Utilization in the Southwest Mountains of China Southwest Forestry UniversityKunming650224China

Tannin foam is a new functional *** can be widely applied to the automobile industry,construction industry,and packaging industry due to its wide range of raw materials,renewable,easily degraded,low cost and almost no *** tannin foam is a very complex process that includes high temperature,two phases,mechanical agitation,and phase *** investigate the influence of the stirring velocity and paddle shape,simulation was calculated by making use of the volume of fluid(VOF)method and multiple reference frame(MRF)method in a three-dimensional flow field of tannin-based foaming precursor *** gas holdup and velocity magnitude were analysed with various conditions of mechanical velocities and paddle shape in the stirring flow *** result shows the higher the velocity,the greater the disturbance and paddle shape between the eggbeater and the Rushton turbine,obviously the paddle shape of the eggbeater with a wider range of agitation,which can entrap more air into the tannin-based foaming precursor resin in a short *** when the speed is 1500 rpm,the flow field of the Rushton turbine comes out of a ditch,which decreases the efficiency of mass transfer;there is less air to mix into the tannin-based foaming precursor resin,which causes *** the same time,the eggbeater shows the marvelous capability of hybrid as it has two vortexes and multiple cycles that make a difference from the Rushton turbine,which has only one vortex and two upper and lower loops;the structure makes the flow field more stable allowed evenness of flow field tannin-based foaming precursor *** results reveal that it is beneficial for tannin-based foaming precursor resin to use an eggbeater with a speed of 1500 rpm to reduce the consumption of resources while obtaining a uniform flow field.

关键词： Tannin-based foaming precursor resin mechanical agitation numerical simulation volume of fluid(VOF) multiple reference frame(MRF)

Study on Chaotic Characteristics of the Friction Process between High Hardness Alloy Steel and Cemented Carbide under C60 Nanoparticle Fluid Lubrication

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工程与科学中的计算机建模(英文) 2024年第1期138卷 525-550页

作者： jingshan Huang Bin Yao Qixin lan Zhirong Pan School of Aerospace Engineering Xiamen UniversityXiamen361005China

Friction and wear phenomenon is a complex nonlinear system,and it is also a significant problem in the process of metal *** order to systematically analyze the friction and wear process of tool material-workpiece material friction pair in the cutting process of high hardness alloy steel under different lubrication conditions,the chaotic characteristics of friction process between high hardness alloy steel and cemented carbide under the lubrication C60 nano-particles fluid are studied based on the chaos ***,the friction and wear experiments of the friction pair between high hardness alloy steel and cemented carbide tool are carried out based on the ring-block friction and wear tester,and the results of friction force signal in time domain and wear width are ***,the friction signals in time domain are processed and transformed based on phase space reconstruction and recurrence plot theory,and the recurrence plots of different experimental groups under different lubrication conditions are *** evolution law of recurrence plot is further observed and studied,and the recursive quantitative index is ***,the cutting experiments of tool wear are carried *** results show that the proposed method can intuitively and accurately reveal the wear evolution process and the wear feature identification law of the tool material-high hardness alloy steel pair under different lubrication ***,it is found that when the concentration of C60 nanoparticles is 200∼300 ppm,the stability of the friction pair system is *** proposed method can provide a strategy for wear prediction in cutting process,and provide a theoretical basis and technical support for antifriction lubrication methods in practical cutting applications.

关键词： C60 nanoparticles recurrence plot friction stability