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Experimental investigation of junction growth of rough contacts using X-ray computed tomography

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Friction 2024年第11期12卷 2519-2531页

作者： runliang WANG Jianhua LIU bo LIU Duo JIA Xiaoyu DING School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China AECC Shenyang Engine Research Institution Shenyang 110000China

The real contact area(RCA)of randomly rough contacts has received a great deal of attention because it correlates strongly with friction,lubrication,sealing,and *** have revealed that the RCA associated with deterministic normal squeezing loads increases when tangential loads are also applied,in a phenomenon called junction ***,experimental investigations of the junction growth of randomly rough contacts are ***,we used X-ray computed tomography(CT)to measure junction growth when two aluminum alloy surfaces were in contact.A high-resolution experimental setup was used to apply loads and observe contact behaviors at a resolution of 4μ*** RCA and average contact gaps were computed using a three-dimensional(3D)geometric model constructed from gray CT images using the Otsu thresholding *** results showed that the RCA increased as the normal load *** RCA increased by 22.67%after a tangential load was applied(junction growth),and the average gap decreased by 14.01%after a tangential load was ***,X-ray CT accurately measured the junction growth as a novel quantitative method.

关键词： three-dimensional(3D)contact analyses real contact area(RCA),junction growth X-ray computed tomography(CT) assembly interfaces

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改进群体智能算法的无线传感器网络覆盖优化

西南大学学报（自然科学版） 2024年第1期46卷 155-166页

作者：贾润亮张海玉山西省财政税务专科学校信息学院太原030024 太原理工大学财经学院太原030024

为解决无线传感器网络(Wireless Sensor Networks,WSN)节点分布不均和随机部署中的低覆盖率问题,该文提出一种改进群体智能算法的无线传感器网络覆盖优化算法,即改进的黑猩猩优化和哈里斯鹰优化的混合优化算法(Improved Chimp Optimizat... 详细信息

为解决无线传感器网络(Wireless Sensor Networks,WSN)节点分布不均和随机部署中的低覆盖率问题,该文提出一种改进群体智能算法的无线传感器网络覆盖优化算法,即改进的黑猩猩优化和哈里斯鹰优化的混合优化算法(Improved Chimp Optimization and Harris Hawk Optimization Algorithm,ICHHO).该算法首先对黑猩猩优化算法(Chimpanzee Optimization Algorithm,ChOA)进行改进,使用Levy Flight来改善其探索阶段,然后设计一个更新的公式来计算猎物逃逸能量,作为开发和探索之间的选择因素.传感器节点随机部署后,将ICHHO在传感器节点上执行,按照改进策略更新个体位置信息,计算相应的适应程度,找到最优传感器位置,并根据传感器概率模型确定网络最优覆盖率.仿真结果验证了ICHHO对于解决WSN覆盖问题的适用性,与其他优化算法的对比结果显示,ICHHO在提高覆盖率方面优于其他算法.

关键词：无线传感器网络黑猩猩优化哈里斯鹰优化覆盖率群体智能算法

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环境风条件下接触网腕臂装置机械强度研究

机械管理开发 2024年第8期39卷 1-3,6页

作者：程润良浙江省轨道交通建设管理集团有限公司浙江杭州310000

接触网腕臂装置时刻受到环境风等因素的影响,使腕臂装置机械强度下降,基于流固理论及有限元理论,对不同风速作用下腕臂装置的机械强度进行研究。研究表明:在80 m/s时的风压达到最大,正定位腕臂装置的风压为120 kPa,反定位腕臂装置的风压... 详细信息

接触网腕臂装置时刻受到环境风等因素的影响,使腕臂装置机械强度下降,基于流固理论及有限元理论,对不同风速作用下腕臂装置的机械强度进行研究。研究表明:在80 m/s时的风压达到最大,正定位腕臂装置的风压为120 kPa,反定位腕臂装置的风压为118 kPa;瞬时风速30~70 m/s作用下,腕臂装置的应力都小于最大许用应力,机械强度满足要求;当瞬时风速达到80 m/s时,腕臂装置的应力都超过最大许用应力,机械强度不能满足要求。

关键词：接触网腕臂装置环境风机械强度应力分析

t分布与螺旋黏菌搜索的混沌自适应秃鹰搜索算法

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小型微型计算机系统 2024年第8期45卷 1854-1862页

作者：张海玉贾润亮太原理工大学财经学院太原030024 山西省财政税务专科学校信息学院太原030024

针对秃鹰搜索算法搜索精度低、收敛速度慢及易于陷入局部最优的不足,提出t分布与螺旋黏菌搜索的混沌自适应秃鹰搜索算法.首先引入混沌bernoulli映射进行种群初始化,丰富种群多样性;然后在搜索空间猎物阶段利用螺旋黏菌搜索策略依搜索进... 详细信息

针对秃鹰搜索算法搜索精度低、收敛速度慢及易于陷入局部最优的不足,提出t分布与螺旋黏菌搜索的混沌自适应秃鹰搜索算法.首先引入混沌bernoulli映射进行种群初始化,丰富种群多样性;然后在搜索空间猎物阶段利用螺旋黏菌搜索策略依搜索进程动态修正位置更新方式,提高算法全局搜索能力和收敛精度;在俯冲捕获猎物阶段引入自适应惯性权重策略平衡算法全局搜索与局部开发,提高算法求解精度;最后利用t分布随机扰动策略依概率对种群个体变异,增加算法跳离局部最优、找到全局最优的概率.利用基准函数对算法寻优性能进行实验评估,并引入Wilcoxon秩和检验评估算法搜索性能.结果表明:改进秃鹰搜索算法在寻优精度和收敛速度上都得到了更大提升.

关键词：秃鹰搜索算法混沌映射黏菌算法惯性权重 t分布收敛性

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black hole shadows in Einstein-bel-Robinson gravity

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Chinese Physics C 2024年第5期48卷 272-283页

作者： b.Hamil b.C.Lütfüoğlu Laboratoire de Physique Mathématique et Subatomique Facultédes Sciences ExactesUniversitéConstantine 1ConstantineAlgeria Department of Physics University of Hradec KrálovéRokitanského 6250003 Hradec KrálovéCzechia

Gravity models given by higher-order scalar curvature corrections are believed to bear important consequences. Einstein-bel-Robinson (EbR) gravity with quartic curvature modification motivated Sajadi et al. to explore static spherically symmetric black hole solutions using perturbative methods. In this study, inspired by their work, we investigate AdS black hole shadows in EbR gravity and demonstrate how the gravity parameter alters the energy emission rate. Finally, we address the same problem in the presence of plasma, because the black holes are thought to be surrounded by a medium that changes the geodesic of photons.

关键词： black hole shadows Einstein-bel-Robinson gravity plasma

Soils in extraterrestrial space: Need for studies under microgravity

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Pedosphere 2024年第1期34卷 13-14页

作者： M.b.KIRKHAM Department of Agronomy Kansas State UniversityManhattan KS 66506USA

With the increased interest of plants in space, gravity cannot be ignored when studying soil-plant-water relations. Therefore, it is important to understand the water relations of soils under zero gravity in space or under reduced gravity on the Moon or Mars. This paper outlines the problems of moving water in soils under zero gravity or microgravity, as well as growing plants in these soils. It is suggested that microgravity experiments could be done on Earth using both soils and plants. Results from such experiments could be used to grow plants when mankind establishes bases on the Moon and Mars.

关键词： soils soil bases

Water Vapor Information from Satellite and Its Applications

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Advances in Atmospheric Sciences 2024年第1期41卷 188-189页

作者： b.J.SOHN School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826Korea

Water vapor is a critical component of the hydrological cycle because it plays a vital role in transporting water from one part of the cycle to *** vapor evaporated from surfaces such as oceans,lakes,and rivers conden... 详细信息

关键词： motion oceans lakes

数字孪生水利赋能水利新质生产力发展框架研究

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中国水利 2024年第8期 6-10,5页

作者：钱峰夏润亮水利部信息中心北京100053

发展新质生产力是推动高质量发展的内在要求和重要着力点。进入新发展阶段,数字孪生水利因其具有高科技、高效能、高质量特征,成为水利新质生产力的最显著标志和最有力抓手。水利部党组将推进数字孪生水利建设作为推动新阶段水利高质量... 详细信息

发展新质生产力是推动高质量发展的内在要求和重要着力点。进入新发展阶段,数字孪生水利因其具有高科技、高效能、高质量特征,成为水利新质生产力的最显著标志和最有力抓手。水利部党组将推进数字孪生水利建设作为推动新阶段水利高质量发展的显著标志和重要路径,其本质就是在发展水利新质生产力。基于新质生产力的科学内涵和重大意义,探讨辨析建设数字孪生水利与发展新质生产力之间的内在联系和逻辑,并从建设行动、关键技术、标准体系、人才培养等方面提出以数字孪生水利驱动引领水利新质生产力发展的实施路径。

关键词：新质生产力数字孪生水利水利高质量发展科技创新

CompactChain:an efficient stateless chain for UTXO-model blockchain

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Frontiers of Computer Science 2024年第2期18卷 167-179页

作者： b Swaroopa REDDY T Uday Kiran REDDY Department of Electrical Engineering Indian Institute of Technology HyderabadHyderabadTelangana 502285India

In this work,we propose a stateless blockchain called CompactChain,which compacts the entire state of the UTXO(Unspent Transaction Output)based blockchain systems into two RSA *** first accumulator is called Transaction Output(TXO)commitment which represents the TXO *** second one is called Spent Transaction Output(STXO)commitment which represents the STXO *** this work,we discuss three algorithms:(i)To update the TXO and STXO commitments by the *** miner also provides the proofs for the correctness of the updated commitments;(ii)To prove the transaction’s validity by providing a membership witness in TXO commitment and non-membership witness against STXO commitment for a coin being spent by a user;(iii)To update the witness for the coin that is not yet spent;The experimental results evaluate the performance of the CompactChain in terms of time taken by a miner to update the commitments and time taken by a validator to verify the commitments and validate the *** compare the performance of CompactChain with the existing state-of-the-art works on stateless *** shows a reduction in commitments update complexity and transaction witness size which inturn reduces the mempool size and propagation latency without compromising the system throughput(Transactions per second(TPS)).

关键词： stateless blockchain RSA Accumulator STXO commitment TXO commitment UTXO Non-interactive Proof of Exponentiation(NI-PoE) Transactions per second(TPS)