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Experimental determination of the Young’s modulus of individual single-walled carbon nanotubes with single chirality

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Nano Research 2024年第8期17卷 7522-7532页

作者： Jianlin Sun Xiao Zhang Yanchun wang Mingming Li Xiaojun Wei Huaping Liu Weiya Zhou Beijing National Laboratory for Condensed Matter Physics and Institute of PhysicsChinese Academy of SciencesBeijing 100190China School of Physical Sciences and College of Materials Science and Optoelectronic Technology University of Chinese Academy of SciencesBeijing 100049China Songshan Lake Materials Laboratory Dongguan 523808China Beijing Key Laboratory for Advanced Functional Materials and Structure Research Beijing 100190China

One-dimensional carbon nanotube(CNT)exhibits excellent mechanical properties and is considered to be an ideal candidate material for the space ***,subtle changes in its chirality strongly affect its physical and chemical properties,including mechanical properties(such as Young's modulus,YM).Theoretical studies reveal that the YMs of perfect single-walled carbon nanotubes(SWCNTs)are in the order of TPa and related to their ***,due to the lack of SWCNTs samples with well-defined structures and the difficulties in mechanical tests on individual SWCNTs,the theoretical correlations between YM and structure of SWCNTs have not been verified and are still in debate,which directly influences the practical utilization of the excellent mechanical properties of *** this work,we have developed an experimental method to measure the YM of an individual micrometer-scale suspended CNT by atomic force microscopy.A distinct regularity is found between the YM and chirality(i.e.,chiral angle and diameter)of SWCNT in the experiment for the first *** comparing the YMs of SWCNTs with similar diameters and different chiral angles,it manifests that the SWCNT with a near zigzag configuration has a larger *** finding suggests that the effect of SWCNT’s structures on the YMs cannot be *** developed method of measuring YMs of SWCNTs will be valuable for further experimental research on the inherent physical and chemical properties of SWCNTs.

关键词： Young's modulus single-walled carbon nanotubes single chirality atomic force microscopy

Perception Enhanced Deep Deterministic Policy Gradient for Autonomous Driving in Complex Scenarios

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 557-576页

作者： Lyuchao Liao Hankun Xiao Pengqi Xing Zhenhua Gan Youpeng He Jiajun wang Fujian Provincial Key Laboratory of Automotive Electronics and Electric Drive Fujian University of TechnologyFuzhou350118China Fujian Provincial Universities Engineering Research Center for Intelligent Driving Technology Fuzhou350118China

Autonomous driving has witnessed rapid advancement;however,ensuring safe and efficient driving in intricate scenarios remains a critical *** particular,traffic roundabouts bring a set of challenges to autonomous driving due to the unpredictable entry and exit of vehicles,susceptibility to traffic flow bottlenecks,and imperfect data in perceiving environmental information,rendering them a vital issue in the practical application of autonomous *** address the traffic challenges,this work focused on complex roundabouts with multi-lane and proposed a Perception EnhancedDeepDeterministic Policy Gradient(PE-DDPG)for AutonomousDriving in the ***,themodel incorporates an enhanced variational autoencoder featuring an integrated spatial attention mechanism alongside the Deep Deterministic Policy Gradient framework,enhancing the vehicle’s capability to comprehend complex roundabout environments and make ***,the PE-DDPG model combines a dynamic path optimization strategy for roundabout scenarios,effectively mitigating traffic bottlenecks and augmenting throughput *** experiments were conducted with the collaborative simulation platform of CARLA and SUMO,and the experimental results show that the proposed PE-DDPG outperforms the baseline methods in terms of the convergence capacity of the training process,the smoothness of driving and the traffic efficiency with diverse traffic flow patterns and penetration rates of autonomous vehicles(AVs).Generally,the proposed PE-DDPGmodel could be employed for autonomous driving in complex scenarios with imperfect data.

关键词： Autonomous driving traffic roundabouts deep deterministic policy gradient spatial attention mechanisms

A Railway Fastener Inspection Method Based on Abnormal Sample Generation

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 565-592页

作者： Shubin Zheng Yue wang Liming Li Xieqi Chen Lele Peng Zhanhao Shang Higher Vocational and Technical College Shanghai University of Engineering ScienceShanghai200437China School of Urban Railway Transportation Shanghai University of Engineering ScienceShanghai201620China Shanghai Engineering Research Centre of Vibration and Noise Control Technologies for Rail Transit Shanghai University of Engineering ScienceShanghai201620China

Regular fastener detection is necessary to ensure the safety of ***,the number of abnormal fasteners is significantly lower than the number of normal fasteners in real *** supervised inspectionmethods have insufficient detection ability in cases of imbalanced *** solve this problem,we propose an approach based on deep convolutional neural networks(DCNNs),which consists of three stages:fastener localization,abnormal fastener sample generation based on saliency detection,and fastener state ***,a lightweight YOLOv5s is designed to achieve fast and precise localization of fastener ***,the foreground clip region of a fastener image is extracted by the designed fastener saliency detection network(F-SDNet),combined with data augmentation to generate a large number of abnormal fastener samples and balance the number of abnormal and normal ***,a fastener inspection model called Fastener ResNet-8 is constructed by being trained with the augmented fastener *** show the effectiveness of our proposed method in solving the problem of sample imbalance in fastener *** and quantitative comparisons show that the proposed F-SDNet outperforms other state-of-the-art methods in clip region extraction,reaching MAE and max F-measure of 0.0215 and 0.9635,*** addition,the FPS of the fastener state inspection model reached 86.2,and the average accuracy reached 98.7%on 614 augmented fastener test sets and 99.9%on 7505 real fastener datasets.

关键词： Railway fastener sample generation inspection model deep learning

An inversely designed integrated spectrometer with reconfigurable performance and ultra-low power consumption

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Opto-Electronic Advances 2024年第8期7卷 43-54页

作者： Ang Li Yifan Wu Chang wang Feixia Bao Zongyin Yang Shilong Pan National Key Laboratory of Microwave Photonics Nanjing University of Aeronautics and AstronauticsNanjing 210016China Key Lab of Modern Optical Technologies of Education Ministry of China Soochow UniversitySuzhou 215006China College of Information Science and Electronic Engineering Zhejiang UniversityHangzhou 310058China

Despite the pressing demand for integrated spectrometers,a solution that deliver high-performance while being practically operated is still ***,current integrated spectrometers lack reconfigurability in their performance,which is highly desirable for dynamic working *** study presents a viable solution by demonstrating a userfriendly,reconfigurable spectrometer on *** the core of this innovative spectrometer is a programmable photonic circuit capable of exhibiting diverse spectral responses,which can be significantly adjusted using on-chip phase *** distinguishing feature of our spectrometer lies in its inverse design approach,facilitating effortless control and efficient manipulation of the programmable *** eliminating the need for intricate configuration,our design reduces power consumption and mitigates control ***,our reconfigurable spectrometer offers two distinct operating *** the Ultra-High-Performance mode,it is activated by multiple phase-shifters and achieves exceptional spectral resolution in the picometer scale while maintaining broad *** the other hand,the Ease-of-Use mode further simplifies the control logic and reduces power consumption by actuating a single-phase *** this mode provides a slightly degraded spectral resolution of approximately 0.3 nm,it prioritizes ease of use and is wellsuited for applications where ultra-fine spectral reconstruction is not a primary requirement.

关键词： silicon photonics integrated spectrometers computational spectrometers

A dual-function selection system enables positive selection of multigene CRISPR mutants and negative selection of Cas9-free progeny in Arabidopsis

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aBIOTECH 2024年第2期5卷 140-150页

作者： Feng-Zhu wang Ying Bao Zhenxiang Li Xiangyu Xiong Jian-Feng Li State Key Laboratory of Biocontrol Guangdong Provincial Key Laboratory of Plant ResourcesSchool of Life SciencesSun Yat-sen UniversityGuangzhou 510275China

The CRISPR/Cas9 technology revolutionizes targeted gene knockout in diverse organisms including ***,screening edited alleles,particularly those with multiplex editing,from herbicide-or antibiotic-resistant transgenic plants and segregating out the Cas9 transgene represent two laborious *** solutions to facilitate these processes rely on different selection ***,by taking advantage of the opposite functions of a D-amino acid oxidase(DAO)in detoxifying D-serine and in metabolizing non-toxic D-valine to a cytotoxic product,we develop a DAO-based selection system that simultaneously enables the enrichment of multigene edited alleles and elimination of Cas9-containing progeny in Arabidopsis *** five DAOs tested in Escherichia coli,the one encoded by Trigonopsis variabilis(TvDAO)could confer slightly stronger D-serine resistance than other *** expression of TvDAO in Arabidopsis allowed a clear distinction between transgenic and nontransgenic plants in both D-serine-conditioned positive selection and D-valine-conditioned negative *** a proof of concept,we combined CRISPR-induced single-strand annealing repair of a dead TvDAO with D-serine-based positive selection to help identify transgenic plants with multiplex editing,where D-serine-resistant plants exhibited considerably higher co-editing frequencies at three endogenous target genes than those selected by ***,D-valine-based negative selection successfully removed Cas9 and TvDAO transgenes from the survival offspring carrying inherited ***,this work provides a novel strategy to ease CRISPR mutant identification and Cas9 transgene elimination using a single selection marker,which promises more efficient and simplified multiplex CRISPR editing in plants.

关键词： CRISPR Genome editing D-amino acid oxidase Cas9-free Selection marker

Multi-Objective Optimization of Aluminum Alloy Electric Bus Frame Connectors for Enhanced Durability

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 735-755页

作者： Wenjun Zhou Mingzhi Yang Qian Peng Yong Peng Kui wang Qiang Xiao Key Laboratory of Traffic Safety on Track Ministry of EducationSchool of Traffic&Transportation EngineeringCentral South UniversityChangsha410018China School of Mechanical and Automotive Engineering Xiamen University of TechnologyXiamen361024China

The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to *** issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame *** study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and *** research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body *** goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector *** typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and ***,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation ***,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic ***,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint ***,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending *** joint component showcased a remarkable 30%–40%mass reduction while boosting energy *** design optimization method exhibits high efficiency and *** contemporary automation technology,the design optimiza

关键词： Aluminum connectors three-point bending simulation parametric design model multi-objective collaborative optimization

Effect of Lightweight Aggregates Incorporation on the Mechanical Properties and Shrinkage Compensation of a Cement-Ground Granulated Blast Furnace Slag-Phosphogypsum Ternary System

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1773-1784页

作者： Yu wang Mengyang Ma Yong Long Qingxiang Zhao Zhifei Cheng State Key Laboratory of Bridge Intelligent and Green Construction China Railway Major Bridge Engineering Group Co.Ltd.Wuhan430034China China Railway Bridge Science Research Institute. Ltd.Wuhan430034China

Shrinkage-induced cracking is a common issue in concrete structures,where the formation of cracks not only affects the aesthetic appearance of concrete but also potentially reduces its durability and *** this study,the effect of ceramsite sand addition on the properties of a ternary system of cement-ground granulated blast furnace slag(GGBFS)-phosphogypsum(PG)is *** particular,the fluidity,rheology,hydration heat,compressive strength,autogenous shrinkage,and drying shrinkage of the considered mortar specimens are *** results indicate that an increase in PG content leads to a decrease in fluidity,higher viscosity,lower exothermic peak,and lower compressive ***,the shrinkage of the mortar specimens is effectively *** incorporation of internal curing water from ceramsite sand improves fluidity,decreases both yield stress and viscosity,enhances the degree of hydration,and induces mortar ***,the inferior mechanical properties of the ceramsite sand generally produce a decrease in the compressive strength.

关键词： Phosphogypsum ceramsite sand internal curing mechanical property shrinkage

Analysis and Optimization of Transient Mode Switching Behavior for Power Split Hybrid Electric Vehicle with Clutch Collaboration

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Automotive Innovation 2024年第1期7卷 150-165页

作者： Dehua Shi Sheng Liu Yujie Shen Shaohua wang Chaochun Yuan Long Chen Automotive Engineering Research Institute Jiangsu UniversityZhenjiang 212013China Jiangsu Province Engineering Research Center of Electric Drive System and Intelligent Control for Alternative Vehicles Zhenjiang 212013China

The power split hybrid electric vehicle(HEV)adopts a power coupling configuration featuring dual planetary gearsets and multiple clutches,enabling diverse operational modes through clutch engagement and *** multi-clutch configuration usually involves the collaboration of two clutches during the transient mode switching process,thereby substantially elevating control *** study focuses on power split HEVs that integrate multi-clutch mechanisms and investigates how different clutch collaboration manners impact the characteristics of transient mode *** powertrain model for the power-split HEV is established utilizing matrix-based *** the formulation of clutch torque curves and clutch collaboration models,this research systematically explores the effects of clutch engagement timing and the duration of clutch slipping state on transient mode switching *** upon this analysis,an optimization problem for control parameters pertaining to the two collaborative clutches is *** simulated annealing algorithm is employed to optimize these control *** results demonstrate that the clutch collaboration manners have a great influence on the transient mode switching *** with the pre-calibrated benchmark and the optimal solution derived by the genetic algorithm,the maximal longitudinal jerk and clutch slipping work during the transient mode switching process is reduced obviously with the optimal control parameters derived by the simulated annealing *** study provides valuable insights for the dynamic coordinated control of the power-split HEVs featuring complex clutch collaboration mechanisms.

关键词： Power split hybrid electric vehicle Transient mode switching Clutch collaboration Simulated annealing Powertrain model

Caloric restriction,Sirtuins,and cardiovascular diseases

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Chinese Medical Journal 2024年第8期137卷 921-935页

作者： Ziyu Wei Bo Yang Huiyu wang Shuangjie Lv Houzao Chen Depei Liu State Key Laboratory of Common Mechanism Research for Major Diseases Department of Biochemistry and Molecular BiologyInstitute of Basic Medical SciencesChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100005China

Caloric restriction(CR)is a well-established dietary intervention known to extend healthy lifespan and exert positive effects on aging-related diseases,including cardiovascular ***,a family of nicotinamide adenine dinucleotide(NAD^(+))-dependent histone deacetylases,have emerged as key regulators of cellular metabolism,stress responses,and the aging process,serving as energy status sensors in response to ***,the mechanism through which CR regulates Sirtuin function to ameliorate cardiovascular disease remains *** review not only provided an overview of recent research investigating the interplay between Sirtuins and CR,specifically focusing on their potential implications for cardiovascular health,but also provided a comprehensive summary of the benefits of CR for the cardiovascular system mediated directly via *** has also been shown to have considerable impact on specific metabolic organs,leading to the production of small molecules that enter systemic circulation and subsequently regulate Sirtuin activity within the cardiovascular *** direct and indirect effects of CR offer a potential mechanism for Sirtuin modulation and subsequent cardiovascular *** the interplay between CR and Sirtuins will provide new insights for the development of interventions to prevent and treat cardiovascular diseases.

关键词： Caloric restriction Sirtuins Cardiovascular diseases Healthy lifestyle Dietary