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Atomistic understanding of rough surface on the interfacial friction behavior during the chemical mechanical polishing process of diamond

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Friction 2024年第6期12卷 1119-1132页

作者： Song YUAN Xiaoguang GUO Hao wang Renke KANG shang GAO State Key Laboratory of High-performance Precision Manufacturing Dalian University of TechnologyDalian 116024China

The roughness of the contact surface exerts a vital role in *** is still a significant challenge to understand the microscopic contact of the rough surface at the atomic ***,the rough surface with a special root mean square(RMS)value is constructed by multivariate Weierstrass–Mandelbrot(W–M)function and the rubbing process during that the chemical mechanical polishing(CMP)process of diamond is mimicked utilizing the reactive force field molecular dynamics(ReaxFF MD)*** is found that the contact area A/A0 is positively related with the load,and the friction force F depends on the number of interfacial bridge *** the surface roughness will increase the friction force and friction *** model with low roughness and high lubrication has less friction force,and the presence of polishing liquid molecules can decrease the friction force and friction *** RMS value and the degree of damage show a functional relationship with the applied load and lubrication,i.e.,the RMS value decreases more under larger load and higher lubrication,and the diamond substrate occurs severer damage under larger load and lower *** work will generate fresh insight into the understanding of the microscopic contact of the rough surface at the atomic level.

关键词： diamond random roughness reactive force field molecular dynamics(ReaxFF MD) friction Weierstrass-Mandelbrot(W-M)function chemical mechanical polishing(CMP)

MXene:Promising materials for magnesium-ion batteries

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Chinese Journal of Chemical Engineering 2024年第5期69卷 199-211页

作者： Liuyu Song Haibo Li Pengkai wang Yu shang Yue Yang Zhaoyu Wu School of Resources and Civil Engineering Northeastern UniversityShenyang 110004China

Magnesium-ion batteries(MIBs)have attracted extensive attention due to their high theoretical capacity,superior safety,and low ***,the development of MIBs is hindered by the lack of cathode materials with long cycle life and rate *** stands out as a prime choice for MIB cathode or collector for anode-free magnesium batteries(AFMBs)because of its larger surface area,adjustable surface properties,and good electrical *** this paper,we summarized the preparation and layering methods of MXene and discussed the prospects of MXene as a cathode or collector for *** review will be immensely beneficial in critically analyzing the synthesis techniques and the applications of MXene material as MIB cathode or AFMB *** addition,the challenges of the preparation and layering were concluded,along with raising the research strategies of MXene for storing Mg ions.

关键词： MXene Nanomaterials Electrochemistry Optimization Magnesium-ion batteries(MIBs)

The Adjustment Analysis Method of the Active Surface Antenna Based on Convolutional Neural Network

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Research in Astronomy and Astrophysics 2024年第6期24卷 294-306页

作者： You Ban shang Shi Na wang Qian Xu Shufei Feng School of Mechanical Engineering Xinjiang UniversityUrumqi 830017China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China

Active surface technique is one of the key technologies to ensure the reflector accuracy of the millimeter/submillimeter wave large reflector *** antenna is complex,large-scale,and high-precision equipment,and its active surfaces are affected by various factors that are difficult to comprehensively deal *** this paper,based on the advantage of the deep learning method that can be improved through data learning,we propose the active adjustment value analysis method of large reflector antenna based on deep *** method constructs a neural network model for antenna active adjustment analysis in view of the fact that a large reflector antenna consists of multiple panels spliced *** on the constraint that a single actuator has to support multiple panels(usually 4),an autonomously learned neural network emphasis layer module is designed to enhance the adaptability of the active adjustment neural network *** classical 8-meter antenna is used as a case study,the actuators have a mean adjustment error of 0.00252 mm,and the corresponding antenna surface error is0.00523 *** active adjustment result shows the effectiveness of the method in this paper.

关键词： techniques:radar astronomy telescopes methods:analytical methods:numerical

C2-phenyl-substituted benzimidazolium-based covalent organic framework as efficient catalyst for CO_(2) conversion without solvents,metals,and cocatalysts

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Science China Chemistry 2024年第2期67卷 551-557页

作者： Zhenzhen Wu Jing wang Lili Liu shang Guo Juan Li Xianming Zhang Shanxi Institute for Functional Food Shanxi Agricultural UniversityTaiyuan030031China Institute of Crystalline Materials Shanxi UniversityTaiyuan030006China Key Laboratory of Interface Science and Engineering in Advanced Materials College of ChemistryTaiyuan University of TechnologyTaiyuan030024China

Covalent organic frameworks(COFs) are a potential platform for carbon dioxide(CO_(2)) conversion owing to their periodic permanent porosity,adjustable structure,and chemical *** good catalytic performance in CO_(2) conversion,collaborative multifunctions should be strategically integrated into the catalytic system design and *** this study,a four-in-one high-efficiency catalyst was synthesized and tested for CO_(2) cycloaddition to form cyclic *** obtained Tp-MPB-BrCOF had a high nitrogen content,which enhanced its CO_(2) affinity through substantial Lewis acid-base or dipole-quadrupole interactions;moreover,the acid(protons transferring from oxygen(–OH) to nitrogen(–NH)),hydrogen bond donor(hydroxyl group),and Br-(nucleophile group) served as three active sites,further improving the catalyst *** results provide a basis for designing efficient and stable CO_(2)-conversion catalysts.

关键词： covalent organic framework C2-phenyl-substituted benzimidazolium CO_(2)conversion four-in-one catalyst

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可信拜占庭容错共识机制

太原科技大学学报 2024年第2期45卷 132-136页

作者：白尚旺马晓倩高改梅刘春霞太原科技大学计算机科学与技术学院太原030024

针对实用拜占庭容错共识机制中存在共识效率低和激励机制不足的问题,提出一种可信拜占庭容错共识机制。首先,建立引入奖惩机制和时间衰减因子的节点信任评价模型,计算节点的信任值。然后,根据节点信任值进行排序,选择信任值高的节点组... 详细信息

针对实用拜占庭容错共识机制中存在共识效率低和激励机制不足的问题,提出一种可信拜占庭容错共识机制。首先,建立引入奖惩机制和时间衰减因子的节点信任评价模型,计算节点的信任值。然后,根据节点信任值进行排序,选择信任值高的节点组成共识节点集,利用可验证随机函数选取共识节点集中信任值高的节点作为主节点。此外,在拜占庭共识过程中利用BLS签名保证主节点不会作恶。实验仿真结果表明,信任模型可以有效惩罚作恶的节点,可信拜占庭容错共识相比于实用拜占庭容错共识交易吞吐量可以提高43%.

关键词：共识机制奖惩机制时间衰减因子信任值可验证随机函数

Two-Layer Attention Feature Pyramid Network for Small Object Detection

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Computer Modeling in Engineering & Sciences 2024年第10期141卷 713-731页

作者： Sheng Xiang Junhao Ma Qunli shang Xianbao wang Defu Chen College of Information Engineering Zhejiang University of TechnologyHangzhou310023China Binjiang Cyberspace Security Institute of ZJUT Hangzhou310056China

Effective small object detection is crucial in various applications including urban intelligent transportation and pedestrian ***,small objects are difficult to detect accurately because they contain less *** current methods,particularly those based on Feature Pyramid Network(FPN),address this challenge by leveraging multi-scale feature ***,existing FPN-based methods often suffer from inadequate feature fusion due to varying resolutions across different layers,leading to suboptimal small object *** address this problem,we propose the Two-layerAttention Feature Pyramid Network(TA-FPN),featuring two key modules:the Two-layer Attention Module(TAM)and the Small Object Detail Enhancement Module(SODEM).TAM uses the attention module to make the network more focused on the semantic information of the object and fuse it to the lower layer,so that each layer contains similar semantic information,to alleviate the problem of small object information being submerged due to semantic gaps between different *** the same time,SODEM is introduced to strengthen the local features of the object,suppress background noise,enhance the information details of the small object,and fuse the enhanced features to other feature layers to ensure that each layer is rich in small object information,to improve small object detection *** extensive experiments on challenging datasets such as Microsoft Common Objects inContext(MSCOCO)and Pattern Analysis Statistical Modelling and Computational Learning,Visual Object Classes(PASCAL VOC)demonstrate the validity of the *** results show a significant improvement in small object detection accuracy compared to state-of-theart detectors.

关键词： Small object detection two-layer attention module small object detail enhancement module feature pyramid network

Freestanding MoSe_(2)nanoflowers for superior Li/Na storage properties

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Tungsten 2024年第1期6卷 238-247页

作者： Qiao Cu Chao-Qun shang Guo-Fu Zhou Xin wang Guangdong Provincial Key Laboratory of Optical Information Materials South China Normal UniversityGuangzhou 510006China School of Materials Science and Engineering and Hubei Key Laboratory of Plasma Chemistry and Advanced Materials Wuhan Institute of TechnologyWuhan 430205China International Academy of Optoelectronics at Zhaoqing South China Normal UniversityZhaoqing 526060China

MoSe_(2),with high theoretical specific capacity,has attracted a lot of *** remains an open challenge to effectively suppress the irreversible selenium dissolution and rapid capacity decrease induced by severe volume change during ***,we synthesize MoSe_(2)nanoflowers dispersed on one-dimensional(1D)N-doped carbon nanofibers(MoSe_(2)@NCNFs)for use as a freestanding *** this unique structure,the 1D N-doped carbon nanofibers are found to not only enhance the conductivity but also ensure the structural integrity during the Li^(+)/Na^(+)insertion/destraction *** expected,at 2 A·g^(-1),the specific capacity of the MoSe_(2)@NCNFs is maintained at 180 mAh·g^(-1)after 500 cycles when used in lithium storage ***,in the case of sodium storage,at 1 A·g^(-1),the MoSe_(2)@NCNFs shows a capacity of 122mAh·g^(-1)after 500 *** findings suggest that the MoSe_(2)@NCNF electrodes may be a promising candidate for use in reversible Li/Na storage applications.

关键词： Li/Na storage Freestanding electrode MoSe_(2) Electrochemical reaction kinetics Structural integrity

A study of the soil water potential threshold values to trigger irrigation of ‘Shimizu Hakuto’ peach at pivotal fruit developmental stages

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Horticultural Plant Journal 2024年第2期10卷 376-386页

作者： Yusui Lou Yuepeng Han Yubin Miao Hongquan shang Zhongwei Lv Lei wang Shiping wang Horticulture Reseach Institute Henan Academy of Agricultural SciencesZhengzhouHenan 450002China School of Agriculture and Biology Shanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Wuhan Botanical Garden of the Chinese Academy of SciencesWuhanHubei 430074China School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Water management is an important practice that affects fruit size and *** implementation of irrigation scheduling requires knowledge of the appropriate indicators and thresholds,which are established manly based on the effects of water deficits on final fruit *** studies have focused on the real-time effects of water status on fruit and shoot *** establish soil water potential (ψ_(soil)) thresholds to trigger irrigation of peach at pivotal fruit developmental stages,photogrammetry,^(13)C labelling,and other techniques were used in this study to investigate real-time changes in stem diameter,fruit projected area,net leaf photosynthetic rate (P_(n)),and allocation of photoassimilates to fruit under soil water potential conditions ranging from saturation to stress in 6-year-old Shimizu hakuto’*** growth,fruit growth,and P_n exhibited gradually decreasing sensitivity to water deficits during fruit developmental stages I,II,and *** diameter growth was significantly inhibited whenψ_(soil)dropped to-8.5,-7.6,and-5.4 k Pa,*** growth rate was low,reaching zero when theψ_(soil)was-9.0 to-23.1,-14.9 to-21.4,and-16.5 to-23.3 k Pa,respectively,and P_ndecreased significantly when theψ_(soil)reached-24.2,-22.7,and-20.4 kPa,*** addition,more photoassimilates were allocated to fruit under moderateψ_(soil)conditions (-10.1 to-17.0 k Pa) than under otherψ_(soil)*** results revealed threeψ_(soil)thresholds,-10.0,-15.0,and-15.0 kPa,suitable for triggering irrigation during stages I,II,and III,*** thresholds can be helpful for controlling excessive tree vigor,maintaining rapid fruit growth and leaf photosynthesis,and promoting the allocation of more photoassimilates to fruit.

关键词： Peach Soil water potential Irrigation threshold Fruit expansion Photosynthesis

Application of Isogeometric Analysis Method in Three-Dimensional Gear Contact Analysis

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Computer Modeling in Engineering & Sciences 2024年第4期139卷 817-846页

作者： Long Chen Yan Yu Yanpeng shang Zhonghou wang Jing Zhang School of Mechanical Engineering University of Shanghai for Science and TechnologyShanghai200093China Zhejiang Fine-Motion Robot Joint Technology Co. Ltd.Taizhou317600China

Gears are pivotal in mechanical drives,and gear contact analysis is a typically difficult problem to *** isogeometric analysis(IGA)methods have developed new ideas to solve this *** this paper,a threedimensional body parametric gear model of IGA is established,and a theoretical formula is derived to realize single-tooth contact *** were benchmarked against those obtained from commercial software utilizing the finite element analysis(FEA)method to validate the accuracy of our *** findings indicate that the IGA-based contact algorithmsuccessfullymet theHertz contact *** juxtaposed with the FEA approach,the IGAmethod demonstrated fewer node degrees of freedomand reduced computational units,all whilemaintaining comparable ***,the IGA method appeared to exhibit consistency in analysis accuracy irrespective of computational unit density,and also significantlymitigated non-physical oscillations in contact stress across the tooth *** underscores the prowess of IGA in contact *** conclusion,IGA emerges as a potent tool for addressing contact analysis challenges and holds significant promise for 3D gear modeling,simulation,and optimization of various mechanical components.

关键词： Contact analysis involute gear isogeometric analysis finite element analysis