检索结果-南通市图书馆

Significant annealing-induced hardening effect in nanolaminate d-nanotwinne d(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)me dium-entropy alloy by severe cold rolling

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2024年第3期170卷 156-166页

作者： Shuqing Yuan Hui Fu Lei Qian chi Fai Cheung Xu-Sheng Yang State Key Laboratory of Ultra-precision Machining Technology Department of Industrial and Systems EngineeringThe Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518060China

Due to the easy coarsening caused by poor thermal stability,the verified annealing-induced hardening in nanograined metals can only maintain at a relatively low-temperature *** this study,a nanolam-inated(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8)medium-entropy alloy with an average lamellae thickness of∼20 nm embedded by thinner nanotwins was fabricated by severe cold rolling to achieve superior thermal *** with the conventional nanotwinned CrCoNi with nanotwins inside ultra-fined grains,the hier-archical nanolaminated-nanotwinned(CrCoNi)_(97.4)Al_(0.8)Ti_(1.8) exhibits a significant annealing-induced hard-ening effect,i.e.,hardness increasing from∼250 HV in the original specimen to∼500 HV in the cold-rolled status and finally∼630 HV after annealing at 600℃for 1 *** microstructure characterizations reveal that the reduced dislocation density and formation of L1_(2)ordered domain are mainly responsible for such hardening effect,which is facilitated by the effectively suppressed coarsening with annealing temperature,i.e.,slow detwinning process and well-retained low-angle nanolamellar *** coarsening mechanisms from the cold-rolled nanolamellae to the fully recrystallized micro-equiaxed structures under the annealing temperatures ranging from 400 to 800℃ were also elucidated by atomic observations.

关键词： Annealing-induced hardening Thermal stability Nanolaminated-nanotwinned structure CrCoNi Detwinning Grain boundary migration

Transient long-range distance measurement by a Vernier spectral interferometry

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第6期12卷 1107-1114页

作者： LIANG XU KUN WANG CHEN LIU WENYING CHEN chi ZHANG XINLIANG ZHANG Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhan 430074China Optics Valley Laboratory Wuhan 430074China

Rapid and long-range distance measurements are essential in various industrial and scientific applications,and among them,the dual-comb ranging system attracts great attention due to its high ***,the tem-poral asynchronous sampling results in the tradeoff between frame rate and ranging precision,and the non-ambiguity range(NAR)is also limited by the comb cycle,which hinders the further advancement of the dual-comb ranging *** this constraint,we introduce a Vernier spectral interferometry to improve the frame rate and NAR of the ranging ***,leveraging the dispersive time-stretch technology,the dual-comb interferometry becomes spectral ***,the asynchronous time step is unlimited,and the frame rate is improved to 100 ***,dual-wavelength bands are introduced to implement a Vernier spectral interferometry,whose NAR is enlarged from 1.5 m to 1.5 ***,this fast and long-range system also demonstrated high precision,with a 22.91-nm Allan deviation over 10-ms averaging *** a result,the proposed Vernier spectral interferometry ranging system is promising for diverse applications that necessitate rapid and extensive distance measurement.

关键词： interferometry spectral system

Vibration-assisted vat photopolymerization for pixelated-aliasing-free surface fabrication

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2024年第3期6卷 440-456页

作者： Han Xu Renzhi Hu Shuai Chen Junhong Zhu chi Zhou Yong Chen Center for Advanced Manufacturing University of Southern CaliforniaLos AngelesCA 90007United States of America Daniel J.Epstein Department of Industrial and Systems Engineering University of Southern CaliforniaLos AngelesCA 90089United States of America Department of Aerospace and Mechanical Engineering University of Southern CaliforniaLos AngelesCA 90089United States of America Department of Industrial and Systems Engineering University of BuffaloBuffaloNY 14260United States of America

Mask image projection-based vat photopolymerization(MIP-VPP)offers advantages like low cost,high resolution,and a wide material range,making it popular in industry and ***,MIP-VPP employing liquid crystal displays(LCDs)has gained traction,increasingly replacing digital micromirror devices,particularly among hobbyists and in educational settings,and is now beginning to be used in industrial ***,LCD-based MIP-VPPsuffers from pronounced pixelated aliasing arising from LCD’s discrete image pixels and itsdirect-contact configuration in MIP-VPP machines,leading to rough surfaces on the 3D-printed ***,we propose a vibration-assisted MIP-VPP method that utilizes a microscalevibration to uniformize the light intensity distribution of the LCD-based mask image on VPP’s building *** maintaining the same fabrication speed,our technique generates asmoother,non-pixelated mask image,reducing the roughness on flat surfaces and boundary segments of 3D-printed *** light intensity modeling and simulation,we derived an optimal vibration pattern for LCD mask images,subsequently validated by *** assessed the surface texture,boundary integrity,and dimensional accuracy of componentsproduced using the vibration-assisted *** notably smoother surfaces and improved boundary roughness enhance the printing quality of MIP-VPP,enabling its promisingapplications in sectors like the production of 3D-printed optical devices and others.

关键词： additive manufacturing vat photopolymerization piezo vibration sub-pixel resolution aliasing

Determining Sets and Determining Numbers of Finite Groups

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2024年第1期31卷 111-128页

作者： Dengyin Wang chi Zhang Haipeng Qu School of Mathematics China University of Mining and Technology XuzhouJiangsu 221116China School of Mathematics and Computer Science Shanxi Normal University LinfenShanxi 041000China

A subset D of a group G is a determining set of G if every automorphism of G is uniquely determined by its action on D,and the determining number of G,a(G),is the cardinality of a smallest determining set.A group G is called a DEG-group if α(G)equals(G),the generating number of *** main results are as *** groups with determining number 0 or 1 are classified;finite simple groups and finite nilpotent groups are proved to be DEG-groups;for a given finite group H,there is a DEG-group G such that H is isomorphic to a normal subgroup of G and there is an injective mapping from the set of all finite groups to the set of finite DEG-groups;for any integer k≥2,there exists a group G such that α(G)=2 and(G)≥k.

关键词： determining number automorphisms nilpotent groups

A computation design method for architectural artifacts adapted from traditional Kagome bamboo basketry techniques

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2024年第2期13卷 249-264页

作者： Hiroyuki Shinohara Tung Hoi Peter chan School of Architecture The Chinese University of Hong KongHong KongChina

This study is a digital form-finding and manual fabrication experiment in woven architectural design,with one traditional weaving style,Kagome,used to scale the craft up into an architectural-scale bamboo woven *** is a trihexagonal pattern employed in traditional bamboo basketry as a triaxial weaving system,resulting in an object with a self-bracing capacity without the use of fasteners owing to its interlacing *** existing studies and tools have addressed triaxial weaving design and representation,the current consideration of the advantages of weaving with bamboo is *** address this research gap,this study develops a computational design method based on studies on bamboo *** allows for the representation and exploration of design geometries using combinations of regular triangular meshes for the fabrication of Kagome woven bamboo artifacts.A full-scale mock-up was fabricated to evaluate the effectiveness of the *** mock-up demonstrated the self-bracing properties of Kagome,but there were discrepancies between the mock-up and the *** affecting bamboo weaving on an architectural scale have been identified within this study to inform future research on woven bamboo structures.

关键词： Traditionalbamboo craft Triaxialmaterial interlacing Bamboo Computational design methods Mesh block combinationsystem Architecturalwoven artifact

SGT-Net: A Transformer-Based Stratified Graph Convolutional Network for 3D Point Cloud Semantic Segmentation

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第6期79卷 4471-4489页

作者： Suyi Liu Jianning chi Chengdong Wu Fang Xu Xiaosheng Yu Faculty of Robot Science and Engineering Northeastern UniversityShenyang110167China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang110169China SIASUN Robot&Automation Co. Ltd.Shenyang110169China

In recent years,semantic segmentation on 3D point cloud data has attracted much *** 2D images where pixels distribute regularly in the image domain,3D point clouds in non-Euclidean space are irregular and inherently ***,it is very difficult to extract long-range contexts and effectively aggregate local features for semantic segmentation in 3D point cloud *** current methods either focus on local feature aggregation or long-range context dependency,but fail to directly establish a global-local feature extractor to complete the point cloud semantic segmentation *** this paper,we propose a Transformer-based stratified graph convolutional network(SGT-Net),which enlarges the effective receptive field and builds direct long-range ***,we first propose a novel dense-sparse sampling strategy that provides dense local vertices and sparse long-distance vertices for subsequent graph convolutional network(GCN).Secondly,we propose a multi-key self-attention mechanism based on the Transformer to further weight augmentation for crucial neighboring relationships and enlarge the effective receptive *** addition,to further improve the efficiency of the network,we propose a similarity measurement module to determine whether the neighborhood near the center point is *** demonstrate the validity and superiority of our method on the S3DIS and ShapeNet *** ablation experiments and segmentation visualization,we verify that the SGT model can improve the performance of the point cloud semantic segmentation.

关键词： 3D point cloud semantic segmentation long-range contexts global-local feature graph convolutional network dense-sparse sampling strategy

Enhancing Identity Protection in Metaverse-Based Psychological Counseling System

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第1期78卷 617-632页

作者： Jun Lee Hanna Lee Seong chan Lee Hyun Kwon Department of Game Software Hoseo UniversityAsan-si31499Korea Yatav Enter Seoul04799Korea Department of Artificial Intelligence and Data Science Korea Military AcademySeoul01805Korea

Non-face-to-face psychological counseling systems rely on network technologies to anonymize information regard-ing client ***,these systems often face challenges concerning voice data leaks and the suboptimal communication of the client’s non-verbal expressions,such as facial cues,to the *** study proposes a metaverse-based psychological counseling system designed to enhance client identity protection while ensuring efficient information delivery to counselors during non-face-to-face *** proposed systemincorporates a voicemodulation function that instantlymodifies/masks the client’s voice to safeguard their ***,it employs real-time client facial expression recognition using an ensemble of decision trees to mirror the client’s non-verbal expressions through their avatar in the metaverse *** system is adaptable for use on personal computers and smartphones,offering users the flexibility to access metaverse-based psychological counseling across diverse *** performance evaluation of the proposed system confirmed that the voice modulation and real-time facial expression replication consistently achieve an average speed of 48.32 frames per second or higher,even when tested on the least powerful smartphone ***,a total of 550 actual psychological counseling sessions were conducted,and the average satisfaction rating reached 4.46 on a 5-point *** indicates that clients experienced improved identity protection compared to conventional non-face-to-face metaverse counseling ***,the counselor successfully addressed the challenge of conveying non-verbal cues from clients who typically struggled with non-face-to-face psychological *** proposed systemholds significant potential for applications in interactive discussions and educational activities in the metaverse.

关键词： Metaverse counseling system face tracking identity protection

Carbon nanotubes and hexagonal boron nitride nanosheets co-filled ethylene propylene diene monomer composites:Improved electrical property for cable accessory applications

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

High Voltage 2024年第3期9卷 546-555页

作者： Tiandong Zhang Huiduo Xu Chuanxian Dai changhai Zhang Yongquan Zhang Qingguo chi School of Electrical and Electronic Engineering Harbin University of Science and TechnologyHarbinChina

Rubber-based composites based on ethylene propylene diene monomer(EPDM)with excellent non-linear electrical conductivity are preferred to serve as reinforced insu-lation in cable accessories,which can self-adaptively regulate electric field distribution and avoid electric field concentration due to the non-linear *** conductive carbon nanotubes(CNT)are filled into EPDM to improve the non-linear conductivity,while the insulating hexagonal boron nitride nanosheets(h-BN)are used to reconcile the electric breakdown *** results show that with the increase of CNT loading content,the non-linear conductivity of CNT/h-BN/EPDM com-posites becomes more prominent,accompanying the decrease of threshold field strength and increase of non-linear ***,the electric breakdown strength of CNT/h-BN/EPDM composites seriously deteriorates due to the increase of CNT content and *** incorporating 10 wt.%h-BN into the com-posites,the reduction percentage of breakdown strength can be significantly lowered,which is 19.95%of neat EPDM and 13.74%of CNT/h-BN/EPDM composites at 70℃,*** COMSOL Multiphysics simulation results demonstrate that using the CNT/h-BN/EPDM composite as the reinforced insulation can eliminate the electric field concentration of the cable accessory as well as enable the cable accessory with good lightning shock resistance.

关键词： composites hexagonal boron

Programmable silicon-photonic quantum simulator based on a linear combination of unitaries

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Photonics Research 2024年第8期12卷 1760-1767页

作者： YUE YU YULIN chi CHONGHAO ZHAI JIESHAN HUANG QIHUANG GONG JIANWEI WANG State Key Laboratory for Mesoscopic Physics School of PhysicsPeking UniversityBeijing 100871China Frontiers Science Center for Nano-optoelectronics&Collaborative Innovation Center of Quantum Matter Peking UniversityBeijing 100871China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China Yangtze Delta Institute of Optoelectronics Peking UniversityNantong 226010China Hefei National Laboratory Hefei 230088China Department of Electrical and Computer Engineering University of WashingtonSeattleWashington 98195USA china Mobile Research Institute Beijing 100053China

Simulating the dynamic evolution of physical and molecular systems in a quantum computer is of fundamental interest in many *** implementation of dynamics simulation requires efficient quantum *** Lie-Trotter-Suzuki approximation algorithm,also known as the Trotterization,is basic in Hamiltonian dynamics simulation.A multi-product algorithm that is a linear combination of multiple Trotterizations has been proposed to improve the approximation ***,implementing such multiproduct Trotterization in quantum computers remains challenging due to the requirements of highly controllable and precise quantum entangling operations with high success ***,we report a programmable integrated-photonic quantum simulator based on a linear combination of unitaries,which can be tailored for implementing the linearly combined multiple Trotterizations,and on the simulator we benchmark quantum simulation of Hamiltonian *** modify the multi-product algorithm by integrating it with oblivious amplitude amplification to simultaneously reach high simulation precision and high success *** quantum simulator is devised and fabricated on a large-scale silicon-photonic quantum chip,which allows the initialization,manipulation,and measurement of arbitrary four-qubit states and linearly combined unitary *** an example,the quantum simulator is reprogrammed to emulate the dynamics of an electron spin and nuclear spin coupled *** work promises the practical dynamics simulations of real-world physical and molecular systems in future large-scale quantum computers.

关键词： quantum Hamiltonian linearly