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Deployment analysis of composite thin-walled lenticular tubes with effect of storage time and temperature

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Chinese Journal of Aeronautics 2024年第1期37卷 162-172页

作者： Jinfeng deng Ning AN Qilong jia Xiaofei MA School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China State Key Laboratory for Strength and Vibration of Mechanical Structures School of AerospaceXi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Xi’an Institute of Space Radio Technology Xi’an 710100China

Composite Thin-walled Lenticular Tube(CTLT)is increasingly utilized in small satellites missions as a lightweight,foldable,and rollable structural material that facilitates the construction of large deployable *** CTLT is initially flattened and coiled around a central hub for storage before launch,during which elastic energy is stored as deformation energy,allowing it to be self-deployed on demand for use in *** work presents a comprehensive investigation into the coiling,storage and deployment behaviors of CTLT that wraps around a central hub.A nonlinear explicit dynamic finite element model was developed with both deformable CTLT and rigidbodies mechanisms including the central hub and guide rollers,as well as the complex interactions among *** coiling mechanics characteristics such as stored strain energy and rotational moment were presented and validated against experimental data in the ***,the dynamic deployment behaviors were analyzed in terms of two different deployment methods,namely,controlled deployment and free *** effect of material property change during storage was also discussed through numerical experiments.

关键词： Composite deployable structures Deployment dynamics Finite element method Stress relaxation Thin-walled booms

Multi-Fidelity Simulation of Gas Turbine Overall Performance by Directly Coupling High-Fidelity Models of Multiple Rotating Components

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Journal of Thermal Science 2024年第4期33卷 1357-1378页

作者： deng Weimin XU Yibing NI Ming WEI Zuojun gan Xiaohua REN Guangming Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhen518055China School of Aerospace Engineering Tsinghua UniversityBeijing100084China Shenzhen Key Laboratory of Wide-Speed-Range and Variable-Density Continuous Wind Tunnel Shenzhen Science and Technology Innovation CommitteeShenzhen518000China

Multi-fidelity simulations incorporate computational fluid dynamics(CFD) models into a thermodynamic model,enabling the simulation of the overall performance of an entire gas turbine with high-fidelity *** iterative coupled methods rely on characteristic maps,while fully coupled methods directly incorporate high-fidelity ***,fully coupled methods face challenges in simulating rotating components,including weak convergence and complex *** address these challenges,a fully coupled method with logarithmic transformations was developed to directly integrate high-fidelity CFD models of multiple rotating *** developed fully coupled method was then applied to evaluate the overall performance of a KJ66 micro gas turbine across various off-design *** developed fully coupled method was also compared with the traditional iterative coupled ***,experimental data from ground tests were conducted to verify its *** convergence history indicated that the proposed fully coupled method exhibited stable convergence,even under far-off-design *** experimental verification demonstrated that the multi-fidelity simulation with the fully coupled method achieved high accuracy in off-design *** analysis revealed inherent differences in the coupling methods of CFD models between the developed fully coupled and traditional iterative coupled *** inherent differences provide valuable insights for reducing errors between the component-level model and CFD models in different coupling *** developed fully coupled method,introducing logarithmic transformations,offers more realistic support for the detailed and optimal design of high-fidelity rotating components within the overall performance platform of gas turbines.

关键词： multi-fidelity fully coupled method iterative coupled method gas turbine component-level model

The Perturbed Compound Poisson Risk Model with Proportional Investment

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 109-128页

作者： Nai-dan deng Chun-wei Wang jia-en Xu School of Mathematics and Statistics Henan University of Science and TechnologyLuoyang471023China

In this paper, the insurance company considers venture capital and risk-free investment in a constant proportion. The surplus process is perturbed by diffusion. At first, the integro-differential equations satisfied by the expected discounted dividend payments and the Gerber-Shiu function are derived. Then, the approximate solutions of the integro-differential equations are obtained through the sinc method. Finally, the numerical examples are given when the claim sizes follow different distributions. Furthermore, the errors between the explicit solution and the numerical solution are discussed in a special case.

关键词： expected discounted dividend payments lognormal distribution proportional investment perturbed risk model sinc numerical method

Effects of combustion temperature on the optical properties of brown carbon from biomass burning

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Journal of Environmental Sciences 2024年第3期137卷 302-309页

作者： Peng Gao Rule deng Song jia Yue Li Xuefei Wang Qian Xing School of Chemistry Sciences University of Chinese Academy of SciencesBeijing 100049China College of Chemistry and Materials Engineering Beijing Technology and Business UniversityBeijing 100048China

Biomass burning has been known as one of main sources of Brown Carbon(BrC)in *** this study,by controlling the combustion temperature at 250℃,350℃,and 450℃,the methanol soluble organic carbon(MSOC)and methanol insoluble carbon(MISC)from pine wood burning was collected by ***–Vis,excitation emission matrix(EEM),TEM and FTIR spectra were applied to investigate the properties of BrC *** MSOC at 250℃ and 350℃,all the spectral profiles of UV–Vis absorption and excitation emission matrix are almost the same,while the EEM of MSOC at 450℃ are different from that of the other *** MISC fuorescence was observed only in the case of 450℃.In the FTIR spectra,with the temperature increasing the peaks associated to the oxygen-contained functions was weakened,indicating the formation of the fuorophores with larger conjugated system,especially aromatic *** results show that biomass combustion at low temperature produces more oxygen-riched BrC,which possesses relatively lower light absorption,while at high temperature produces more aromatics hydrocarbons with relatively strong light *** results of this work are helpful to trace the source of brown carbon and optimize biomass energy utilization.

关键词： Biomass burning Combustion temperature Methanol-soluble brown carbon EEM Impinger

Effect of Oxygen-Rich Combustion on Flame Propagation of Syngas in a Half-Open Pipe at Elevated Temperatures

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Journal of Thermal Science 2024年第5期33卷 1920-1934页

作者： LI Ningning deng Haoxin XU Zhuangzhuang YAN Mengmeng WEI Shengnan SUN Guangzhen WEN Xiaoping gan Haowen WANG Fahui School of Mechanical and Power Engineering Henan Polytechnic UniversityJiaozuo 454003China

The investigation of syngas flame propagation has great benefits for the effective use of gas *** essay sets out to study the flame propagation of premixed oxygen-rich combustion(oxygen enrichment coefficient in volumeΩ:0.21,0.27,0.32,0.37)of syngas(H_(2):CO=2:8)in half-closed rectangular ducts at elevated temperatures(T:300 K,400 K,500 K)and evaluate the effects of initial temperature and oxygen enrichment coefficient on the LBV from sensitivity analysis and kinetic *** paper presents the effect of the expansion effect on laminar burning velocity for the first time,and separates the effect of the expansion effect on laminar burning velocity by a new *** shows that as the initial temperature goes up,the faster the exponential growth phase of the flame front velocity,the slower the slow growth *** smaller and earlier the maximum flame front velocity arrives,the slower the average flame speed *** the oxygen enrichment coefficient goes up,the peak value of the flame front velocity gradually ***-rich combustion and increasing initial temperature inhibit flame propagation in a half-open tube,but promote laminar burning velocity,which increases the key chemical bond and adiabatic flame *** net reaction rate shows that oxygen-rich combustion mainly promotes the combustion reaction of H_(2)(R2).However,increasing the initial temperature mainly promoted the oxidation of CO(R29).Analysis of the reaction path showed that oxygen-rich combustion and increased initial temperature promoted the reaction of H_(2)and CO with key chemical bonds,increased OH concentration,and inhibited OH cracking reaction.

关键词： gas turbines oxyfuel combustion numerical simulation combustion kinetics fire and flame

A Comparative Study of the Power-law Relationship between the Pulse width and Energy of Precursor and Main Burst

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Research in Astronomy and Astrophysics 2024年第3期24卷 144-168页

作者： Hui-Ying deng Zhao-Yang Peng jia-Ming Chen Dan Zhu College of Physics and Electronic Information Yunnan Normal UniversityKunming 650500China

In gamma-ray burst prompt emission,there is still no consistent conclusion if the precursor and main burst share the same *** this paper,we try to study this issue based on the relationship between pulse width and energy of the precursor and main *** systematically search the light curve data observed by Swift/BAT and Fermi/GBM,and find 13 long bursts with well-structured precursors and main *** fitting the precursor light curve of each different energy channel with the Norris function,we find that there is not only a power-law relationship between precursor width and energy,but also a power-law relationship between the ratio of the rising width to the decaying width and *** comparing the relationship between the precursors and the main burst pulses,we find that the distribution of the precursors and the relationship between the power-law indices are roughly the same as those of the main *** addition,it is found that the precursor width distribution as well as the upper limit of the pulse width ratio does not exceed 1 and both are asymmetric,which are also consistent with the main *** indicate that the precursor and the main burst are indistinguishable,and the precursor and the main burst may have the same physical origin.

关键词： methods data analysis-(stars) gamma-ray burst general-shock waves

Bimetallic CoNi single atoms supported on three-dimensionally ordered mesoporous chromia: highly active catalysts for n-hexane combustion

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Green Energy & Environment 2024年第7期9卷 1122-1137页

作者： Xiuqing Hao Yuxi Liu Jiguang deng Lin Jing jia Wang Wenbo Pei Hongxing Dai Beijing Key Laboratory for Green Catalysis and Separation Key Laboratory of Beijing on Regional Air Pollution Control Key Laboratory of Advanced Functional Materials Education Ministry of China Laboratory of Catalysis Chemistry and Nanoscience Department of Chemical Engineering Faculty of Environment and Life Beijing University of Technology

Developing the alternative supported noble metal catalysts with low cost,high catalytic efficiency,and good resistance toward carbon dioxide and water vapor is critically demanded for the oxidative removal of volatile organic compounds （VOCs）.In this work,we prepared the mesoporous chromia-supported bimetallic Co and Ni single-atom （Co1Ni1/meso-Cr2O3） and bimetallic Co and Ni nanoparticle (CoNPNiNP/mesoCr2O3) catalysts adopting the one-pot polyvinyl pyrrolidone （PVP）-and polyvinyl alcohol （PVA）-protecting approaches,*** results indicate that the Co1Ni1/meso-Cr2O3catalyst exhibited the best catalytic activity for n-hexane (C6H14) combustion (T50%and T90%were 239 and 263℃ at a space velocity of 40,000 mL g-1h-1;apparent activation energy and specific reaction rate at 260℃ were 54.7 kJ mol-1and 4.3×10-7mol g-1cats-1,respectively),which was associated with its higher (Cr5++Cr6+) amount,large n-hexane adsorption capacity,and good lattice oxygen mobility that could enhance the deep oxidation of n-hexane,in which Ni1was beneficial for the enhancements in surface lattice oxygen mobility and low-temperature reducibility,while Co1preferred to generate higher contents of the high-valence states of chromium and surface oxygen species as well as adsorption and activation of n-hexane.n-Hexane combustion takes place via the Mars van Krevelen（MvK） mechanism,and its reaction pathways are as follows:n-hexane→olefins or 3-hexyl hydroperoxide→3-hexanone,2-hexanone or 2,5-dimethyltetrahydrofuran→2-methyloxirane or 2-ethyl-oxetane→acrylic acid→COx→CO2and H2O.

关键词： Three-dimensional ordered mesoporous chromium oxide Supported bimetallic single-atom catalyst Cobalt−nickel single atoms n -Hexane combustion Catalytic reaction mechanism

Synergistic effects of multiscale TiC and dual-phase structure on tensile properties of particle-reinforced steel

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Journal of Iron and Steel Research International 2024年第5期31卷 1232-1245页

作者： Ye jia Xiang-tao deng Qi Wang Cheng-ru Li Hao Wu Zhao-dong Wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

The conventional melting methods were used to obtain in situ TiC particle-reinforced dual-phase steel,followed by hot rolling and heat treatment *** aim was to investigate the effect of TiC particles on the fracture behavior of dual-phase steel at different annealing temperatures,by analyzing the microstructure and tensile behavior of the multiscale TiC particle-reinforced dual-phase *** results showed that TiC particles precipitated in the as-cast microstructure of dual-phase steel were distributed along the grain *** hot rolling,the grain boundary-like morphology of the micron-sized TiC particles was disrupted,and the particles became more refined and evenly distributed in the *** tensile tests revealed that the strength of the TiC particle-reinforced dual-phase steel increased with increasing martensite content,while the elongation *** results were similar to those of conventional *** addition of 1 vol.%multiscale TiC particles improved the strength of the dual-phase steel but did not affect elongation of the *** and holes were primarily concentrated around the TiC particles rather than at the interface of martensite and *** main causes of crack sprouting were TiC particle interface cracking and TiC particle internal ***,the study demonstrated the potential of multiscale TiC particle-reinforced dual-phase steel as a strong and tough *** refined distribution of TiC particles in the matrix improved the strength of the material without compromising its *** results also highlighted the importance of careful selection of reinforcement particles to avoid detrimental effects on the fracture behavior of the material.

关键词： TiC particle Dual-phase structure TiC-reinforced dual-phase steel Tension Fracture behavior

Coordination structure regulation in non-flammable electrolyte enabling high voltage lithium electrochemistry

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Journal of Energy Chemistry 2024年第9期96卷 282-290页

作者： Zhiwen deng Ye jia Yan deng Changhaoyue Xu Xuemei Zhang Qiujie He jianan Peng Hao Wu Wenlong Cai College of Materials Science and Engineering Sichuan UniversityChengdu 610064SichuanChina Engineering Research Center of Alternative Energy Materials and Devices Sichuan UniversityChengdu 610064SichuanChina

High-voltage battery systems bring significant increases in energy density but are also accompanied by fast degradation of electrochemical performance and serious safety ***,Li^(+)coordination structure regulation was conducted to formulate a non-flammable electrolyte,which consists of 1.5 M lithium bis(fluor sulfonyl)imide(LiFSI)in triethyl phosphate and methyl 2,2,2-trifluoromethyl carbonate(FEMC).The renamed TEP-FEMC-FEC(TFF)electrolyte exhibits an FSI^(−)-dominated solvation structure contributed by the weakly-solvating ability of *** generated inorganic-rich interfacial layers are conducive to stabilizing the phase transition of high-voltage cathodes while suppressing the dendritic growth on lithium metal or co-intercalation behavior in graphite *** TFF electrolyte enables LiCoO_(2)||Li batteries to achieve capacity maintenance over 79%after 400 cycles with high-rate of 5 C at an ultra-high voltage of 4.6 V,and an outstanding capacity exceeding 100 mA h g^(−1)even at a super-high current density of 20 ***,the Ah-level LiCoO_(2)||graphite pouch cells also exhibit high capacity retention and satisfactory safety performance even under fast *** work provides a novel research direction for the pursuit of high energy density non-flammable electrolytes.

关键词： Non-flammable Solvation structure High-voltage Lithium batteries