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free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied Mathematics and Mechanics(English Edition) 2024年第3期45卷 543-562页

作者： H.M.fEIZABAD M.H.yas Department of Mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BfRC)beams on the elastic *** different functionally graded(fG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** Hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQM)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BfRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the fG-◇fiber ***,the obtained analysis results of BfRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BfRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(fG)beam elastic foundation generalized differential quadrature method(GDQM)

Dust particle surface potential in an argonhelium plasma using the(r,q)-distribution function

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Communications in Theoretical Physics 2024年第9期76卷 141-148页

作者： Bahaaudin M Raffah A A Abid Abdullah Khan Amin Esmaeili yas Al-Hadeethi M N S Qureshi Department of Physics Faculty of SciencesKing Abdulaziz UniversityJeddah 21589Saudi Arabia Lithography in Devices fabrication and Development Research Group Deanship of Scientific ResearchKing Abdulaziz UniversityJeddah 21589Saudi Arabia Joint Laboratory of Plasma Application Technology Institute of Advanced TechnologyUniversity of Science and Technology of ChinaHefei230026China CAS Key Laboratory of Geospace Environment University of Science and Technology of ChinaHefei230026China Department of Physics Zhejiang Normal UniversityJinhua321005China Department of Physics Graduate School of ScienceTokyo Metropolitan UniversityMinami-Osawa 1-1Hachioji City192-0397Japan Department of Physics GC UniversityLahore 54000Pakistan

In this paper,the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law(r,q)-distribution *** studies have reported the argon-helium plasma and conducted a brief theoretical and experimental *** deepen our understanding further,this study aims to analyze the argon-helium plasma comprehensively using the same pattern but with the(r,q)-distribution *** this purpose,the current balance equations are derived for electron,helium and argon ions,when these charge species attain the quasineutrality *** numerically examined the currents of plasma species for a broad range of effective distribution function parameters r and *** is revealed that the surface potential of dust particles is significantly affected by the parameters r and q,helium ion-to-electron temperature ratio,argon ion-to-electron temperature ratio,and helium ion to argon ion number density *** incorporating the multi-ion(argon-helium)species,the significance of low-temperature nonMaxwellian dusty(complex)plasma is briefly examined.

关键词： dusty plasma dust charge potential plasma physics helium argon plasma r q distribution function non-Maxwellian distribution

Evolution of the“ancient Kedah”:A study on urban forms at Sungai Batu Archaeological Complex(SBAC),Bujang Valley,Kedah,Malaysia

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frontiers of Architectural Research 2024年第1期13卷 127-143页

作者： Mohd Hasfarisham Abd Halim Naizatul Akma Mohd mokhtar Nor Khairunnisa Talib Shyeh Sahibul Karamah Masnan Ahmad fadly Jusoh mokhtar Saidin Kedah Malaysia Universiti Utara Malaysia KedahMalaysia Universiti Sains Malaysia PenangMalaysia

Archaeological research at the Sungai Batu Archaeological Complex(SBAC),which has been carried out until 2023,aims to complete the chronological data and urbanization process of the ancient *** study will especially prove that the ongoing urbanization process is aimed at developing the iron smelting industry and trade in ancient Kedah,especially in *** is because archaeological research at SBAC has proven that with the existence of the ancient Kedah iron smelting workshop at SBAC,river jetties,port management,rituals,and Buddhist monuments began to be erected,all of which can be determined by chronometric *** results of the chronometric dating have proven that the ancient Kedah Kingdom existed since the 6th century BC and was oriented towards the trade of iron resources,which allowed the use of the area to grow *** process of urbanization and land use clearly conforms to Lynch’s principle,which emphasizes the principles of 1)paths,2)edges,3)districts,4)nodes,and 5)landmarks in the development process of land use and urbanization in the complex.

关键词： Chronometric dating Urbanization Land use Monument Iron smelting site

An analytical model to estimate the time delay to reach spontaneous ignition considering heat loss in oil reservoirs

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Petroleum Science 2024年第4期21卷 2469-2474页

作者： James J.Sheng er-Long Yang College of Petroleum Engineering Northeast Petroleum University

During air injection into an oil reservoir, an oxidation reaction generates some heat to raise the reservoir temperature. When the reservoir temperature reaches an ignition temperature, spontaneous ignition occurs. There is a time delay from the injection to ignition. There are mixed results regarding the feasibility of spontaneous ignition in real-field projects and in laboratory experiments. No analytical model is available in the literature to estimate the oxidation time required to reach spontaneous ignition with heat *** paper discusses the feasibility of spontaneous ignition from theoretical points and experimental and field project observations. An analytical model considering heat loss is proposed. Analytical models with and without heat loss investigate the factors that affect spontaneous ignition. Based on the discussion and investigations, we find that it is more difficult for spontaneous ignition to occur in laboratory experiments than in oil reservoirs; spontaneous ignition is strongly affected by the initial reservoir temperature, oil activity, and heat loss; spontaneous ignition is only possible when the initial reservoir temperature is high, the oil oxidation rate is high, and the heat loss is low.

关键词： Spontaneous ignition Time delay Air injection Heat loss Low temperature oxidation Combustion

Research progress in friction stir processing of magnesium alloys and their metal matrix surface composites: Evolution in the 21^(st )century

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Journal of Magnesium and Alloys 2024年第6期12卷 2091-2146页

作者： Roshan Vijay Marode Tamiru Alemu Lemma Nabihah Sallih Srinivasa Rao Pedapati mokhtar Awang Adeel Hassan Department of Mechanical Engineering Universiti Teknologi PETRONASBandarSeri IskandarPerak 32610Malaysia Department of Mechanical Engineering College of EngineeringThe University of Texas Permian BasinMidland-OdessaUnited States Mechanical Engineering Department Universiti Teknologi BruneiBrunei

Rising concerns about climate change drive the demand for lightweight ***(Mg)alloys are highly valued for their low weight,making them increasingly important in various *** focusing on enhancing the characteristics of Mg alloys and developing their Metal Matrix Composites(MMCs)have gained significant attention worldwide over the past decade,driven by the global shift towards lightweight *** Stir Processing(fSP)has emerged as a promising technique to enhance the properties of Mg alloys and produce ***,fSP adapted to refine grain size from the micro to the nano level and accelerated the development of MMCs due to its solid-state nature and the synergistic effects of microstructure refinement and reinforcement,improving strength,hardness,ductility,wear resistance,corrosion resistance,and fatigue ***,producing defect-free and sound fSPed Mg and Mg-MMCs requires addressing several variables and their interdependencies,which opens up a broad range of practical *** existing reviews on individual fSP of Mg,its alloys,and MMCs,an attempt has been made to analyze the latest research on these three aspects collectively to enhance the understanding,application,and effectiveness of fSP for Mg and its *** review article discusses the literature,classifies the importance of Mg alloys,provides a historical background,and explores developments and potential applications of fSPed Mg *** focuses on novel fabrication methods,reinforcement strategies,machine and tool design parameters,material characterization,and integration with other methods for enhanced *** influence of process parameters and the emergence of defects are examined,along with specific applications in mono and hybrid composites and their microstructure *** study identifies promising reinforcement materials and highlights research gaps in fSP for Mg alloys and MMCs *** conclude

关键词： Magnesium alloys friction stir processing Metal matrix composites Lightweight Surface modification

Comparison of engineering failures and seismic responses of 500 kV transformer-bushing systems in the 2022 Luding earthquake

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Earthquake Engineering and Engineering Vibration 2024年第4期23卷 1029-1041页

作者： Zhu Wang Wu Ming’er Xie Qiang Department of Structural Engineering Tongji UniversityShanghai 200092China Key Laboratory of Performance Evolution and Control for Engineering Structures(Tongji University) Shanghai 200092China

Cemented and mechanically clamped types of end fittings(fitting-C and fitting-M)are commonly used in transformer *** the Luding Ms 6.8 earthquake that occurred in China on September 5,2022,all transformer bushings with the two types of end fittings in a 500 kV substation were ***-earthquake field investigations were conducted,and the failures of the two types of bushings were *** elementary simulation models of the transformer-bushing systems were developed to simulate the engineering failures,and further compute their seismic responses for *** results indicate that the hitch lugs of the connection flange are structurally harmful to seismic ***-M can decrease the bending stiffness of the bushing due to the flexible sealing rubber *** it provides a more flexible connection that dissipates energy,the peak accelerations and relative displacements at the top of the bushing are significantly lower than those of the bushing with *** with fitting-C,fitting-M transfers the high-stress areas from the connection flange to the root of the porcelain,so the latter becomes the most vulnerable ***-M increases the failure risk of the low-strength porcelain,indicating the unsuitability of applying it in high-intensity fortification regions.

关键词： transformer bushing end fitting Luding earthquake,engineering failure seismic responses

Health diagnosis of ultrahigh arch dam performance using heterogeneous spatial panel vector model

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Water Science and Engineering 2024年第2期17卷 177-186页

作者： er-feng Zhao Xin Li Chong-shi Gu The National Key Laboratory of Water Disaster Prevention Hohai UniversityNanjing 210098China NationalEngineering Research Centerof Water Resources Eficient Utilization and Engineering Safety Hohai UniversityNanjing 20098China

Currently,more than ten ultrahigh arch dams have been constructed or are being constructed in *** control is essential to long-term operation of these *** study employed the flexibility coefficient and plastic complementary energy norm to assess the structural safety of arch dams.A comprehensive analysis was conducted,focusing on differences among conventional methods in characterizing the structural behavior of the Xiaowan arch dam in ***,the spatiotemporal characteristics of the measured performance of the Xiaowan dam were explored,including periodicity,convergence,and time-effect *** findings revealed the governing mechanism of main ***,a heterogeneous spatial panel vector model was developed,considering both common factors and specific factors affecting the safety and performance of arch *** model aims to comprehensively illustrate spatial heterogeneity between the entire structure and local regions,introducing a specific effect quantity to characterize local deformation ***,the proposed model was applied to the Xiaowan arch dam,accurately quantifying the spatiotemporal heterogeneity of dam ***,the spatiotemporal distri-bution characteristics of environmental load effects on different parts of the dam were reasonably *** of the model prediction enhances its credibility,leading to the formulation of health diagnosis criteria for future long-term operation of the Xiaowan *** findings not only enhance the predictive ability and timely control of ultrahigh arch dams'performance but also provide a crucial basis for assessing the effectiveness of engineering treatment measures.

关键词： Ultrahigh arch dam Structural performance Deformation behavior Diagnosis criterion Panel data model

Nanomedicine targeting ferroptosis to overcome anticancer therapeutic resistance

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Science China(Life Sciences) 2024年第1期67卷 19-40页

作者： Jing Cai Xiaoding Xu Phei er Saw Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation Guangdong-Hong Kong Joint Laboratory for RNA MedicineMedical Research CenterSun Yat-sen Memorial HospitalSun Yat-sen UniversityGuangzhou 510120China Nanhai Translational Innovation Center of Precision Immunology Sun Yat-sen Memorial HospitalSun Yat-sen UniversityFoshan 528200China

A potential reason for the failure of tumor therapies is treatment *** to chemotherapy,radiotherapy,and immunotherapy continues to be a major obstacle in clinic,resulting in tumor recurrence and *** major mechanisms of therapy resistance are inhibitions of cell deaths,like apoptosis and necrosis,through drug inactivation and excretion,repair of DNA damage,tumor heterogeneity,or changes in tumor microenvironment,*** studies have shown that ferroptosis play a major role in therapies resistance by inducing phospholipid peroxidation and iron-dependent cell *** ferroptosis inducers in combination with clinical treatment techniques have been used to enhance the effect in tumor ***,versatile ferroptosis nanoinducers exhibit an extensive range of functions in reversing therapy resistance,including directly triggering ferroptosis and feedback ***,we provide a detailed description of the design,mechanism,and therapeutic application of ferroptosis-mediated synergistic tumor *** also discuss the prospect and challenge of nanomedicine in tumor therapy resistance by regulating ferroptosis and combination therapy.

关键词： ferroptosis cancer therapy therapy resistance nanoinducers

Prospects of the Multi-channel Photometric Survey Telescope in the Cosmological Application of Type Ia Supernovae

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Research in Astronomy and Astrophysics 2024年第4期24卷 183-191页

作者： Zhenyu Wang Jujia Zhang Xinzhong er Jinming Bai Yunnan Observatories Chinese Academy of SciencesKunming 650216China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China International Centre of Supernovae Yunnan Key LaboratoryKunming 650216China South-Western Institute for Astronomy Research Yunnan UniversityKunming 650500China

The Multi-channel Photometric Survey Telescope(Mephisto)is a real-time,three-color photometric system designed to capture the color evolution of stars and transients *** telescope system can be crucial in cosmological distance measurements of low-redshift(low-z,z■0.1)Type Ia supernovae(SNe Ia).To optimize the capabilities of this instrument,we perform a comprehensive simulation study before its official operation is scheduled to *** considering the impact of atmospheric extinction,weather conditions,and the lunar phase at the observing site involving the instrumental features,we simulate light curves of SNe Ia obtained by *** best strategy in the case of SN Ia cosmology is to take the image at an exposure time of 130 s with a cadence of 3 *** this condition,Mephisto can obtain hundreds of high-quality SNe Ia to achieve a distance measurement better than 4.5%.Given the on-time spectral classification and monitoring of the Lijiang 2.4 m Telescope at the same observatory,Mephisto,in the whole operation,can significantly enrich the well-calibrated sample of supernovae at low-z and improve the calibration accuracy of high-z SNe Ia.

关键词： (stars:)supernovae:general (cosmology:)cosmological parameters telescopes