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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

A case study of comparing two dimerized acceptor molecules built by different branch-connected and terminal-connected approaches

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Science China Chemistry 2024年第5期67卷 1687-1696页

作者： Kangqiao Ma Huazhe Liang Yuxin Wang Tengfei He Tainan Duan Xiaodong Si Wendi shi Guankui long Xiangjian Cao Zhaoyang Yao Xiangjian Wan chenxi Li Bin Kan Yongsheng chen State Key Laboratory and Institute of Elemento-Organic Chemistry Frontiers Science Center for New Organic MatterThe Centre of Nanoscale Science and Technology and Key Laboratory of Functional Polymer MaterialsInstitute of Polymer ChemistryRenewable Energy Conversion and Storage Center(RECAST)College of ChemistryNankai UniversityTianjin 300071China School of Materials Science and Engineering National Institute for Advanced MaterialsRenewable Energy Conversion and Storage Center(RECAST)Nankai UniversityTianjin 300350China Chongqing Institute of Green and Intelligent Technology Chongqing SchoolUniversity of Chinese Academy of Sciences(UCAS Chongqing)Chinese Academy of SciencesChongqing 400015China

Dimerized small-molecule acceptors(SMAs) built by the conventional connection of terminal groups of monomers have contributed to exciting long-term stabilities of organic solar cells(OSCs). However, device efficiencies, especially fill factors(FFs), still need to be improved. This probably originates from unsymmetrical molecular structure/conformation-determined less compact/ordered molecular stackings, such as ineffective stackings of constraint terminals. Herein, an exotic dimerized SMA of BC-Th is established by bridging the branched groups(BC-type, branch coupling) of two monomers rather than conventional terminal units(TC-type, terminal coupling). Benefiting from the three-dimensional conformation and more uncurbed terminals,BC-Th exhibits multiple molecular orientations along with a larger dielectric constant and electron mobility compared with TCTh. Finally, an efficiency of 17.43% is achieved by BC-Th-based OSCs, along with the highest FF of 79.13% among all dimerized SMAs-based OSCs to date. When introducing L8-BO as the third component, overall enhanced efficiency of 18.05%and FF of 80.11% are further afforded. Contrarily, TC-Th-based OSCs exhibit much inferior PCE of 16.29% and FF of 74.81%,demonstrating the great advantages of “branch coupling” over “terminal coupling” when building dimerized SMAs.

关键词： organic solar cells dimerized acceptor molecules branch coupling morphology control stability

Intra-Oceanic Subduction Termination and Reinitiation of the Eastern Neo-Tethys in Myanmar

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Journal of Earth Science 2024年第3期35卷 1053-1058页

作者： Yi chen Qinghua Zhang Lin chen Kaihui shi Kyaing Sein State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China Myanmar Geosciences Society Hlaing University CampusYangon 11062Myanmar

Subduction initiation and termination represent the birth and death of a subduction zone and are inevitable elements of terrestrial plate *** evidence demonstrates that subduction zone processes did not operate continuously and might involve multiple initiation and termination stages(Stern,2004),characterized by sustained subduction-zone death and *** geological and numerical studies focus on subduction initiation processes/mechanisms(see reviews in Yang,2022);however,subduction termination is often studied numerically at continental margins(Gerya,2022).How subduction termination proceeds in intra-oceanic settings remains enigmatic due to lacking geological records.

关键词： Eastern terrestrial continental

Multiscale Simulation of Microstructure Evolution during Preparation and Service Processes of Physical Vapor Deposited c-TiAlN Coatings

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Computers, Materials & Continua 2024年第6期79卷 3435-3453页

作者： Yehao long Jing Zhong Tongdi Zhang Li chen Lijun Zhang State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China

Physical Vapor Deposited(PVD)TiAlN coatings are extensively utilized as protective layers for cutting tools,renowned for their excellent comprehensive *** optimize quality control of TiAlN coatings for cutting tools,a multi-scale simulation approach is proposed that encompasses the microstructure evolution of coatings considering the entire preparation and service lifecycle of PVD TiAlN *** scheme employs phase-field simulation to capture the essential microstructure of the PVD-prepared TiAlN ***,cutting simulation is used to determine the service temperature experienced during cutting processes at varying ***-Hilliard modeling is finally utilized to consume the microstructure and service condition data to acquaint the microstructure evolution of TiAlN coatings throughout the cutting *** methodology effectively establishes a correlation between service temperature and its impact on the microstructure evolution of TiAlN *** is expected that the present multi-scale numerical simulation approach will provide innovative strategies for assisting property design and lifespan prediction of TiAlN coatings.

关键词： Multiscale phase-field TiAlN coatings PVD cutting

LLTH‑YOLOv5:A Real‑Time Traffic Sign Detection Algorithm for Low‑Light Scenes

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Automotive Innovation 2024年第1期7卷 121-137页

作者： Xiaoqiang Sun Kuankuan Liu long chen Yingfeng Cai Hai Wang Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China School of Automotive and Traffic Engineering Jiangsu UniversityZhenjiang 212013China

Traffic sign detection is a crucial task for autonomous driving ***,the performance of deep learning-based algorithms for traffic sign detection is highly affected by the illumination conditions of *** existing algo-rithms demonstrate high accuracy in well-lit environments,they suffer from low accuracy in low-light *** paper proposes an end-to-end framework,LLTH-YOLOv5,specifically tailored for traffic sign detection in low-light scenarios,which enhances the input images to improve the detection *** proposed framework comproses two stages:the low-light enhancement stage and the object detection *** the low-light enhancement stage,a lightweight low-light enhancement network is designed,which uses multiple non-reference loss functions for parameter learning,and enhances the image by pixel-level adjustment of the input image with high-order *** the object detection stage,BIFPN is introduced to replace the PANet of YOLOv5,while designing a transformer-based detection head to improve the accuracy of small target ***,GhostDarkNet53 is utilized based on Ghost module to replace the backbone network of YOLOv5,thereby improving the real-time performance of the *** experimental results show that the proposed method significantly improves the accuracy of traffic sign detection in low-light scenarios,while satisfying the real-time requirements of autonomous driving.

关键词： Deep learning Traffic sign detection Low-light enhancement YOLOv5 Object detection

Enhancement of deltaful two-pion exchange nuclear forces

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Communications in Theoretical Physics 2024年第9期76卷 48-54页

作者： Haiming chen Rui Peng Songlin Lyu Bingwei long College of Physics Sichuan UniversityChengduSichuan 610065China School of Physics Peking UniversityBeijing 100871China Southern Center for Nuclear-Science Theory(SCNT) Institute of Modern PhysicsChinese Academy of SciencesHuizhou 516000Guangdong ProvinceChina

The role of the delta isobar degrees of freedom in nucleon–nucleon scattering is *** attempt to understand why the dimensionally regularized two-pion exchanges with the explicit delta isobar is much stronger than the ones with spectral function *** the cutoff value of spectral function regularization is varied,the isoscalar central component exhibits a rather large cut-off *** reveals a surprisingly large numerical factor of the deltaful two-pion exchange *** power counting is adjusted accordingly and we discuss the results and how to improve upon this finding.

关键词： chiral nuclear force delta resonance power counting

Reducing Social Media Attention Inequality in Disasters: The Role of Official Media During Rainstorm Disasters in China

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International Journal of Disaster Risk Science 2024年第3期15卷 388-403页

作者： longfei Zheng Lei chen Fenjie long Jianing Liu Lei Li School of Geography Faculty of Geographical Science Beijing Normal University Hang Lung Center for Real Estate and Department of Construction Management Tsinghua University

Unequal social media attention can lead to potentially uneven distribution of disaster-relief funds, resulting in long-term inequality among regions after disasters. This study aimed to measure inequalities in social media attention to regions during disasters and explore the role of official media in reducing such inequality. This is performed by employing social media,official media, and official aggregated statistics regarding China's rainstorm disasters. Through a set of panel-data regressions and robustness tests, three main conclusions were drawn:(1) There were inequalities among regions regarding social media attention they received during rainstorm disasters. For disasters of the same magnitude, regions with low economic outcome per capita received less attention on social media.(2) Official media can reduce inequality in social media attention during disasters. Official media statements can encourage netizens to pay attention to disaster-stricken areas, and especially the overlooked underdeveloped areas.(3) Of all the measures taken by official media, timely, accurate, and open disclosure of disaster occurrences proved to be the most potent means of leveling the playing field in terms of social media attention;contrarily, promotional or booster-type messages proved futile in this regard. These findings revealed the vulnerabilities within social media landscapes that aff ect disaster relief response, shedding light on the role of official guidance in mitigating inequalities in social media attention during such crises. Our study advises social media stakeholders and policymakers on formulating more equitable crisis communication strategies to bridge the gap in social media attention and foster a more balanced and just relief process.

关键词： China, inequality of attention Official media Rainstorm disasters Situational crisis communication theory Social media

Efficient optimization of electron transfer pathway by constructing phosphide/ceria interface boosts seawater hydrogen production

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Journal of Energy Chemistry 2024年第8期95卷 490-498,I0011页

作者： Yifan Zhao Lingfeng Yang Youyu long Min Xi Anran chen Hua Zhang School of Materials and Energy Yunnan UniversityKunming 650091YunnanChina Electron Microscopy Centre of Yunnan University Yunnan UniversityKunming 650091YunnanChina

Developing efficient and durable hydrogen evolution reaction(HER)electrocatalysts is one of the most important issues for the commercialization of seawater electrolysis,but it remains ***,we report a CeO_(2)-CoP nanoneedle array catalyst loaded on Ti mesh(CeO_(2)-CoP/TM)with workfunction-induced directional charge transport *** CeO_(2)-CoP/TM catalyst showed superior HER catalytic activity and stability,with over potentials of 41 and 60 mV to attain 10 mA cm^(-2),in 1 M KOH and 1 M KOH+seawater electrolyte,*** results and theoretical calculations reveal that the work function drives the charge transfer from CeO_(2)to CoP,which effectively balances the electronic density of CoP and CeO_(2),optimizes the d-band center,and accelerates the water activation kinetics,thus enhancing the HER *** solar-driven water electrolysis device displays a high and stable solar-to-hydrogen conversion efficiency of 19.6%.This study offers a work function-induced directional charge transport strategy to design efficient and durable catalysts for hydrogen production.

关键词： Work function Heterostructure Charge transport Seawater splitting Solar-to-hydrogen

Phase deviation of semi-active suspension control and its compensation with inertial suspension

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Acta Mechanica Sinica 2024年第6期40卷 141-153页

作者： Yi Yang Changning Liu long chen Xiaoliang Zhang School of Automotive and Traffic Engineering(Automotive Engineering Research Institute) Jiangsu UniversityZhenjiang212013China Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHong KongChina

The performance of vehicle suspension is evaluated based on three conflicting indexes:body acceleration,suspension deflection,and dynamic tire load,which vary across different frequency *** suspension control strategy faces the challenge to strike a balance among these *** research analyzes the fundamental mechanism of control phase deviation effects on skyhook damper control,groundhook damper control,and acceleration drive damper *** the perspective of complex domain mechanical impedance with the support of the inertial suspension,a structure-based compensation approach is proposed to address for the control phase *** simulation analysis demonstrates that the coordination of inertial suspension structure and control strategy can effectively enhance the comprehensive suspension performance across entire frequency ***,a semi-active inertial suspension bench is *** experimental results indicate that the suspension with the semi-active inertial suspension has outstanding vibration isolation ability,and enhances the suspension performance at ride comfort,suspension deflection,and road friendly significantly.

关键词： Vibration isolation Vibration control Phase deviation Control compensation Semi-active suspension