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Multi-objective constructal design for quadrilateral heat generation body based on thermal-entransy theory and NSGA-Ⅱ

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Science china(Technological Sciences) 2024年第9期67卷 2777-2786页

作者： CHEN LinGen ZHU HongWei GE YanLin SHI ShuangShuang FENG HuiJun institute of Thermal Science and Power engineering Wuhan Institute of TechnologyWuhan 430205China Hubei Provincial engineering Technology research Center of Green Chemical Equipment Wuhan 430205China School of Mechanical Electrical EngineeringWuhan Institute of TechnologyWuhan 430205China

Based on thermal-entransy theory, the multi-objective constructal design of quadrilateral heat generation body(HGB) with similar shapes of leaves is studied further. The relationship between the aspect ratio of quadrilateral HGB and average temperature difference based on thermal-entransy dissipation is compared with that between the aspect ratio of quadrilateral HGB and the maximum temperature difference(MTD). The relationship between a composite function, consisting of linear weighting sum of the average temperature difference and MTD, and aspect ratio is obtained, and the optimal aspect ratios under minimum composite function with different weighting coefficients are obtained. Using the NSGA-Ⅱ algorithm, the Pareto frontier containing a series of compromise results of average temperature difference and MTD is obtained, and optimization results are compared using the deviation index. There is no aspect ratio to make both MTD and average temperature difference reach the minimum, and the optimal aspect ratio under the minimum MTD is smaller than that under the minimum average temperature difference. The optimal aspect ratio is obtained by making the composite function reach the minimum, and the optimal aspect ratios obtained by minimizing the composite function with different weighting coefficients are different. Compared with the construct of the initial design, the value of the composite function with optimal construct decreases by 1.9%, and the aspect ratio of the quadrilateral HGB decreases by 9.1%. The average temperature difference with the optimal construct increases by 2.1%, and the MTD with the optimal construct decreases by 5.6%. The deviation index under multi-objective optimization is smaller than that under single-objective optimization, and the obtained construct has better comprehensive thermal conductivity. Compared with TOPSIS and LINMAP decision-making methods, the average temperature difference with composite function optimization increases by 0.5

关键词： thermal-entransy theory constructal theory heat conduction quadrilateral heat generation body composite function NSGA-Ⅱ

Constructal design of a rectangular parallel phase change microchannel in a three-dimensional electronic device

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Science china(Technological Sciences) 2024年第5期67卷 1381-1390页

作者： ZHANG JiWen FENG HuiJun CHEN LinGen GE YanLin institute of Thermal Science and Power engineering Wuhan Institute of TechnologyWuhan430205China College of Power engineering Naval University of EngineeringWuhan430033China Hubei Provincial engineering Technology research Center of Green Chemical Equipment Wuhan430205China School of Mechanical&Electrical engineering Wuhan Institute of TechnologyWuhan430205China

Based on constructal theory,a rectangular parallel phase change microchannel model in a three-dimensional electronic device(TDED)is established with R134a as the cooling *** on the minimization of a complex function(CF)composed of linear weighting sum of maximum temperature difference and pumping power consumption,constructal design of the TDED is conducted first;and then,maximum temperature difference and pumping power consumption are minimized by non-dominated sorting genetic algorithm-II *** results reveal that there exist an optimal mass flow rate(0.0012 kg/s)and a quadratic optimal aspect ratio(AR)(0.39)of the microchannel which lead to quadratic minimum CF(0.817).Compared with the original value,the CF after optimization is reduced by 18.34%.Reducing the inlet temperature of cooling fluid and microchannel number appropriately can help to enhance the overall performance of *** using the artificial neural network and genetic algorithms in the toolboxes of Matlab software,the optimal AR gained in the Pareto solution set is located between 0.2–*** smallest deviation index among three discussed strategies is 0.346,and the corresponding optimal AR is 0.413,which is selected as the optimal design strategy of the microchannel in the TDED under multiple *** findings in this study can serve as theoretical guides for thermal designs of electronic devices.

关键词： constructal theory parallel microchannel evaporation phase change three-dimensional electronic device multi-objective optimization artificial neural network

Constructal design of a rectangular porous fin considering minimization of maximum temperature difference and pumping power consumption

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Science china(Technological Sciences) 2024年第3期67卷 919-929页

作者： LIU XiaoYe FENG HuiJun CHEN LinGen GE YanLin institute of Thermal Science and Power engineering Wuhan Institute of TechnologyWuhan 430205China College of Power engineering Naval University of EngineeringWuhan 430033China Hubei Provincial engineering Technology research Center of Green Chemical Equipment Wuhan 430205China School of Mechanical&Electrical engineering Wuhan Institute of TechnologyWuhan 430205China

A heat dissipation model of a rectangular porous fin is established based on constructal theory. First, the constructal design of rectangular porous fin is conducted by selecting a complex function minimization, which composed of linear weighting sum of maximum temperature difference and pumping power consumption, as optimization objective. Effects of gap height, air inlet velocity, total porous fin volume and porosity on the optimal constructs are investigated, respectively. The findings show that the complex function can attain its double minimum at a value of 0.802 when the fin length and number are optimized, and the corresponding optimal fin length and number are 8.01 mm and 10, respectively. In comparison to original design, the complex function and maximum temperature difference after twice optimization are decreased by 19.80% and 66.31%, ***, the comprehensive performance of porous fin is improved by simultaneously optimizing the fin length and number. The artificial neural network is applied to predict the fin performances, which is used to conduct multi-objective optimization based on NSGA-II algorithm. Optimal structure of porous fin for multiple requirements is gained by LINMAP and TOPSIS decisionmaking strategies. The findings in this study can serve as theoretical guides for fin thermal designs of electronic devices.

关键词： constructal theory rectangular porous fin pumping power consumption maximum temperature difference complex function multi-objective optimization

Effects of Atmospheric Pressure on Developmental Characteristics and the Stability of Air Entraining Agent for Concrete

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 979-989页

作者：李立辉牛开民 TIAN Bo CHEN Xin FU Ziqian ZHU Xuwei School of Civil engineering Chongqing Jiaotong UniversityChongqing 400074China Transportation Science and engineering Harbin Institute of TechnologyHarbin 150090China research institute of Highway Ministry of TransportBeijing 100088China

In order to ascertain the effects of atmospheric pressure on developmental characteristics and the stability of AEA(air-entraining agent)solution bubbles,AEA solution experiments and AEA solution bubble experiments were,respectively,conducted in Peking(50 m,101.2 kPa)and Lhasa(3,650 m,63.1 kPa).Surface tensions and inflection-point concentrations were tested based on AEA solutions,whilst developmental characteristics,thicknesses and elastic coefficients of liquid films were tested based on air bubbles of AEA *** study involved three types of AEAs,which were TM-O,226A,and *** experimental results show that initial sizes of TM-O,226A,and 226S are,respectively,increased by 43.5%,17.5%,and 3.8%.With the decrease of ambient pressure,the drainage rate and the drainage index of AEA solution bubbles *** experiments show that the liquid film thicknesses of all tested AEA solution bubbles are in micron *** the atmospheric pressure decreases from 101.2 to 63.1 kPa,the liquid film thicknesses of three types of AEA solutions decrease in various degrees;and film elasticities at critical thicknesses *** film of 226S solution bubbles is the most stable,presenting as a minimum thickness *** should be noted that elastic coefficient of liquid film only represents the level at critical thickness,thus it can not be applied as the only evaluating indicator of bubble *** a type of AEA,factors affecting the stability of its bubbles under low atmospheric pressure include initial bubbles size,liquid film thickness,liquid film elasticity,ambient temperature,etc.

关键词： air-entraining agent surface tension bubble size liquid film thickness liquid film elasticity atmospheric pressure

A discussion of fatigue properties of notched specimens subjected to prestressing treatment machined from FGH4097

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Chinese Journal of Aeronautics 2024年第4期37卷 508-523页

作者： Rongxi SHI Dasheng WEI Le HAN Shun YANG School of Energy and Power engineering Beihang UniversityBeijing 100191China Jiangxi research institute Beihang UniversityNanchang 330096China research institute of Aero-Engine Beihang UniversityBeijing 100191China

Experimental and numerical investigations were performed to reveal the effect of prestress on the fatigue properties of FGH4097 so as to quantitatively evaluate the overspeed benefit of the disc of aeroengine. A corresponding experiment was performed to examine the effect of prestress on the fatigue life of FGH97. A complete model describing the fatigue properties of the prestressed notch specimen was proposed. After the modification of mean stress, stress gradient and prestressing treatment, the model is finally verified by fatigue test of presstressed notch specimens machined from FGH4097 with satisfactory accuracy and good engineering applicability. The new model highlights that for the variable fatigue loads, the introduction of appropriate prestress is expected to benefit to the notch specimens and certainly to the disc of aeroengine regards of their fatigue properties. Both the calculation method of fatigue life parameters and the prestress correction model are proved to have good prediction accuracy.

关键词： Turbine blisk Overspeed test Prestress Fatigue life prediction FGH4097

Global analysis of basic leucine zipper transcription factors in trifoliate orange and the function identification of PtbZIP49 in salt tolerance

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Horticultural Plant Journal 2024年第1期10卷 115-130页

作者： Yuanyuan Xu Qiuling Hui Meng Li Hongxian Peng Yizhong He Changpin Chun Liangzhi Peng Xingzheng Fu National Citrus engineering research Center Citrus Research InstituteSouthwest UniversityChongqing 400712China

As one of the most widely distributed and highly conserved transcription factors in eukaryotes,basic leucine zipper proteins(bZIPs)are involved in a variety of biological processes in plants,but they are largely unknown in *** this study,56 bZIP family members were identified genome-wide from an important citrus rootstock,namely trifoliate orange(Poncirus trifoliata ***.),and these putative bZIPs were named PtbZIP1—*** PtbZIPs were classified into 13 subgroups by phylogenetic comparison with Arabidopsis thaliana bZIPs(AtbZIPs),and they were randomly distributed on nine known(50 genes)chromosomes and one unknown(6 genes)*** analysis revealed the detailed characteristics of PtPZIPs,including their amino acid length,isoelectric point(pI),molecular weight(MW),predicted subcellular localization,gene structure,and conserved *** of promoter elements suggested the presence of drought,low-temperature,wound,and defense and stress responsive elements,as well as multiple hormone-responsive cis-acting *** expression analysis showed the transcriptional patterns of PtbZIPs in different tissues and under dehydration,high salt,ABA,and IAA *** addition,21 PtbZIPs were predicted to have direct or indirect protein—protein *** these,PtbZIP49 was experimentally proven to interact with PtbZIP1 or PtbZIP11 by using a yeast two-hybrid assay and bimolecular fluorescence complementation(BiFC).Subcellular localization analysis further revealed that PtbZIP1,PtbZIP11,and PtbZIP49 were localized in the ***,PtbZIP49 was functionally identified as having an important role in salt stress via ectopic expression in *** and silenced in trifoliate orange using virus-induced gene silencing(VIGS).This study provided comprehensive information on PtbZIP transcription factors in citrus and highlights their potential functions in abiotic stress.

关键词： bZIP Citrus Trifoliate orange Abiotic stress Expression pattern

Computation of the exact time delay margin for vehicle platoon under generic communication topologies

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Journal of Traffic and Transportation engineering(English Edition) 2024年第4期11卷 761-775页

作者： Xu Zhu Maode Yan Panpan Yang Yongtao Liu School of Electronic and Control engineering Chang'an UniversityXi'an 710064China School of automobile Chang'an UniversityXi'an 710064China

Due to the limited bandwidth and transmission congestion of the vehicle platoon's communication,it is inevitable to induce time delay,which significantly degrades the control performance of the vehicle platoon,even resulting in *** paper focuses on analyzing the internal stability under generic communication topologies and presents a method of computing the exact time delay margin(ETDM).The proposed method can offer a necessary and sufficient internal stability condition with no ***,to reduce the analytical complexity and computational burden elegantly,we decompose the closed-loop platoon dynamics into a set of individual subsystems via similarity transformation and matrix *** decomposition approach is applicable for any general communication ***,an explicit formula is deduced to compute the ETDM by surveying the characteristic roots'distribution of all these individual *** is further demonstrated that only the positive purely imaginary roots need to be considered to compute the ***,simulations are conducted to demonstrate the effectiveness of the theoretical claims.

关键词： Vehicle platoon Exact time delay margin Generic communication topologies System decomposition Characteristic roots'distribution

Observation and verification of surface electrical explosion driven by radial-distributed pulsed current in laboratory lightning strike test

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High Voltage 2024年第1期9卷 137-149页

作者： Ruoyu Han Yuchen Cao Yakun Liu Xi Chen Ting Li Chen Li Pengfei Li State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijingChina School of Mechatronical engineering Beijing Institute of TechnologyBeijingChina Department of Electrical engineering Shanghai Jiaotong UniversityShanghaiChina Beijing institute of Astronautical System engineering BeijingChina Aerospace research institute of Materials and Processing Technology BeijingChina

The laboratory lightning test is essential for assessing the effectiveness of lightning strike protection(LSP).Particularly,direct lightning strike damage can be performed with pulsed current injection into the *** paper focuses on the dynamic process of arc plasma and shock wave behaviour in the vicinity of the‘strike’point.A rod-plate discharge load is built for testing aluminium and coated plate under 40-kA-level pulsed *** visualisation of the luminous discharge plasma and its flow field via high-speed photography(from different angles)is meticulously designed and implemented,synchronised with electro-physical *** results indicate some new mechanisms for lightning strike damage,apart from the impulse heat loading from the thermal *** transient current injection through the arc root concentrates on a thin skin layer(skin-depth effect),with the radial-attenuated current density,driving asynchronously electrical explosions on the plate *** inhomogeneous Joule heating of the plate leads to outwardly propagating phase transition and shock wave along the conductive *** addition,the electro-thermal instability is observed and regarded as the seed of irregular erosion *** information reveals two different plasma states of main discharge arc channel and adjacent surface electrical *** correspondence of the physical mechanism of electrical explosion and optical radiation is *** images for different regions depict erosion characteristics and summarise influencing factors,further confirming the mechanism *** research clarifies the role of skin-depth effect in transaction arc erosion for electrode,complements the electrical explosion theory with unevenly distributed current and helps optimise strategies of LSP.

关键词： electrical lightning radial

Functional Optical Fiber Sensors Detecting Imperceptible Physical/Chemical Changes for Smart Batteries

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Nano-Micro Letters 2024年第8期16卷 268-308页

作者： Yiding Li Li Wang Youzhi Song Wenwei Wang Cheng Lin Xiangming He institute of Nuclear and New Energy Technology Tsinghua UniversityBeijing 100084People’s Republic of China National engineering research Center of Electric Vehicles Beijing Institute of Technology(BIT)Beijing 100081People’s Republic of China Shenzhen Automotive research institute of BIT(Shenzhen research institute of National engineering research Center of Electric Vehicles) Shenzhen 518118People’s Republic of China

The battery technology progress has been a contradictory process in which performance improvement and hidden risks *** the battery is still a“black box”,thus requiring a deep understanding of its internal *** battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing *** paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety *** paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”*** the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed *** advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system ***,with the help of smart batteries in the future,the importance of consistency can be weakened or even *** application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life.

关键词： Smart battery Advanced embedded optical fiber sensor Battery internal physical/chemical state Quality-reliability-life characteristic