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Speed limit effect during lane change in a two-lane lattice model under V2X environment

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Chinese Physics B 2024年第3期33卷 718-722页

作者：金灿彭光含聂方彦 college of Physical Science and Technology Guangxi Normal UniversityGuilin 541004China Guangxi Key Laboratory of Nuclear Physics and Technology Guangxi Normal UniversityGuilin 541004China Information and modern Education Technology Center Hunan University of Arts and ScienceChangde 415000China Computer and Information Engineering college Guizhou University of CommerceGuiyang 550014China

Speed limit measures are ubiquitous due to the complexity of the road environment,which can be supplied with the help of vehicle to everything(V2X)communication ***,the influence of speed limit on traffic system will be investigated to construct a two-lane lattice model accounting for the speed limit effect during the lane change process under V2X ***,the stability condition and the mKdV equation are closely associated with the speed limit effect through theory ***,the evolution of density and hysteresis loop is simulated to demonstrate the positive role of the speed limit effect on traffic stability in the cases of strong reaction intensity and high limited speed.

关键词： traffic flow lattice model speed limit

A theory for three-dimensional response of micropolar plates

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Applied Mathematics and Mechanics(English Edition) 2024年第8期45卷 1403-1414页

作者： Dianwu HUANG Linghui HE college of Civil Engineering and Architectural Jiaxing University Department of modern Mechanics and State Key Laboratory of Fire Science University of Science and Technology of China

Through combined applications of the transfer-matrix method and asymptotic expansion technique, we formulate a theory to predict the three-dimensional response of micropolar plates. No ad hoc assumptions regarding through-thickness assumptions of the field variables are made, and the governing equations are two-dimensional, with the displacements and microrotations of the mid-plane as the unknowns. Once the deformation of the mid-plane is solved, a three-dimensional micropolar elastic field within the plate is generated, which is exact up to the second order except in the boundary region close to the plate edge. As an illustrative example, the bending of a clamped infinitely long plate caused by a uniformly distributed transverse force is analyzed and discussed in detail.

关键词： 74H45 asymptotic expansion micropolar plate O341 three-dimensional response transfer-matrix

The effect of Ti and Zr content on the structure,mechanics and energy-release characteristics of Ti—Zr—Ta alloys

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Defence Technology（防务技术） 2024年第1期31卷 343-350页

作者： Jia-yu Meng Jing-zhi He Bin Zhang Jin Chen Shun Li Dun Niu Yu Tang Xi’an modern Chemistry Research Institute Xi'an710065China college of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China

Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage *** this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-Ta alloys with good casting performance were *** microstructure of the Ti_(x)ZrTa alloys gradually change from BCC+HCP to single BCC structure with the increase of *** the Ti_(2)Zr_(y)Ta alloys was still uniform and single BCC structure with the increase of *** evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-Ta *** synergistic effect of dual phase structure increases the fracture strain of Ti_(x)ZrTa(x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)ZrTa(x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obstacles for dislocation *** as Zr content increases,the fracture strain of Ti_(2)Zr_(y)Ta alloys decrease,then the oxidation reaction rate and fragmentation degree gradually *** higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)ZrTa alloys with low Ti content and Ti_(2)Zr_(y)Ta alloys with high Zr content.

关键词： Energetic structural materials Ti-Zr-Ta Multi-element alloy Energy release characteristics

Fabricating a smart clothing system based on strain-sensing yarn and novel stitching technology for health monitoring

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Science China(Technological Sciences) 2024年第2期67卷 587-596页

作者： TANG Jian WU YuTing MA ShiDong ZHANG YuMin XU RuoJie YAN Tao PAN ZhiJuan college of Textile and Clothing Engineering Soochow UniversitySuzhou 215123China National Engineering Laboratory for modern Silk Suzhou 215123China

Various yarn-shaped flexible strain sensors have recently been ***,research is lacking on additive manufacturing for smart clothing for integrating yarn sensors with commercial ***,a strain-sensing yarn is sewn into a piece of fabric through a novel stitching technique,and the influence of the stitching method and needle pitch on the sensing performance is investigated using finite element analysis(FEA).The sensing performance could be improved when the sensing yarn is self-locked in the fabric at the needle eyes,and the needle pitch was reduced to 0.5 cm,which is attributed to the enhanced stress and strain ***,the composite sensing fabric featured outstanding performance,including a low detection limit(0.1%),rapid response(280 ms),excellent durability(10000 cycles),and high stability(negligible drift and frequency independence).In addition,the remarkable wear resistance,washability,and anti-interference to ambient humidity and perspiration were ***,the optimal stitch trace lengths of sensing yarn for detecting elbow motion,breathing,and heartbeats are ***,a smart clothing system composed of smart clothing,data acquisition unit,and mobile APP was developed to simultaneously detect human movement and physiological *** work provides a reference to produce intelligent garments based on yarn sensors for health monitoring.

关键词： strain-sensing yarn composite sensing fabric smart clothing system stitching technology health monitoring

Numerical Analysis on the Static Performance of Gas Journal Bearing by Using Finite Element Method

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Nanomanufacturing and Metrology 2024年第1期7卷 28-47页

作者： Pengfeng Wang Yuntang Li Xiang Gao Yueliang Ye Ruirui Li Xiaolu Li Yuan Chen Jie Jin Cong Zhang college of modern Science and Technology China Jiliang UniversityJinhua 322002China college of Mechanical and Electrical Engineering China Jiliang UniversityHangzhou 310018China

In this paper,finite element method is used to calculate the static performance of gas journal bearing,in which rotation speed term is introduced into the stiffness matrix of linear triangular element to realize the performance calculation of the bearing with rotation *** results indicate that the average gas film thicknesses corresponding to the maximum load capac-ity and stiffness,and the minimum attitude angle increase with the growth of orifice *** capacity and stiffness significantly improved with the increase of rotation speed,eccentricity ratio and supply pressure when the bearing has thin average gas film *** angle increases with the growth of rotation speed,while the growth rate slows down or even decreases at high *** most effective way of reducing attitude angle is to increase supply *** can be found that rotation speed affects attitude angle through changing gas pressure difference between two orifices,while other parameters have the same effect by changing gas pressure at orifice outlet.

关键词： Finite element method(FEM) Gas journal bearing Stiffness matrix Attitude angle

Evaluation of the intracellular lipid-lowering effect of polyphenols extract from highland barley in HepG2 cells

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Food Science and Human Wellness 2024年第1期13卷 454-461页

作者： Yijun Yao Zhifang Li Bowen Qin Xingrong Ju Lifeng Wang college of Food Science and Engineering/Collaborative Innovation Centre for modern Grain Circulation and Safety Nanjing University of Finance and EconomicsNanjing 210023China

Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against *** practical application,the research of food combinations is more significant than a specific food *** study investigated the lipid-lowering effect of highland barley polyphenols via lipase assay in vitro and HepG2 cells induced by oleic acid(OA).Five indexes,triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein-cholesterol(LDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),were used to evaluate the lipidlowering effect of highland barley *** also preliminary studied the lipid-lowering mechanism by Realtime fluorescent quantitative polymerase chain reaction(q PCR).The results indicated that highland barley extract contains many components with lipid-lowering effects,such as hyperoside and *** vitro,the lipase assay showed an 18.4%lipase inhibition rate when the additive contents of highland barley extract were 100μg/m *** intracellular lipid-lowering effect of highland barley extract was examined using 0.25 mmol/L OA-induced HepG2 *** results showed that intracellular TG,LDL-C,and T-CHO content decreased by 34.4%,51.2%,and 18.4%,*** and AST decreased by 51.6%and 20.7%compared with the untreated hyperlipidemic HepG2 cells.q PCR results showed that highland barley polyphenols could up-regulation the expression of lipid metabolism-related genes such as PPARγand Fabp4.

关键词： Highland barley Polyphenols extract Lipid-lowering effect HepG2 cells

YOLO-Drone:A Scale-Aware Detector for Drone Vision

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Chinese Journal of Electronics 2024年第4期33卷 1034-1045页

作者： Yutong LI Miao MA Shichang LIU Chao YAO Longjiang GUO School of Computer Science Shaanxi Normal University Key Laboratory of modern Teaching Technology Ministry of Education college of Computer Science Sichuan University

Object detection is an important task in drone vision. Since the number of objects and their scales always vary greatly in the drone-captured video, small object-oriented feature becomes the bottleneck of model performance, and most existing object detectors tend to underperform in drone-vision scenes. To solve these problems, we propose a novel detector named YOLO-Drone. In the proposed detector, the backbone of YOLO is firstly replaced with ConvNeXt, which is the state-of-the-art one to extract more discriminative features. Then, a novel scale-aware attention(SAA) module is designed in detection head to solve the large disparity scale problem. A scale-sensitive loss(SSL) is also introduced to put more emphasis on object scale to enhance the discriminative ability of the proposed detector. Experimental results on the latest VisDrone 2022 test-challenge dataset(detection track) show that our detector can achieve average precision(AP) of 39.43%, which is tied with the previous state-of-the-art, meanwhile,reducing 39.8% of the computational cost.

关键词： YOLO Costs Object oriented modeling Computational modeling Detectors Feature extraction Data models

Single-step-etched ultra-compact metamaterial grating coupler enabled by a hierarchical inverse design approach

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 119-126页

作者： Qiao Wang Ruiqi Luo Nan Liu Maojing Hou Bo Xiong Guandong Liu Wei Ma Intelligent Network Research Institute Zhejiang LabHangzhou 311100China State Key Laboratory of modern Optical Instrumentation College of Information Science and Electronic EngineeringZhejiang UniversityHangzhou 310027China

With the concept of metamaterials introduced into integrated photonics,subwavelength structures have gained popularity for their ability to create devices with ultra-compact size,high performance,and versatile ***,traditional metamaterial design methods are usually based on empirical templates and physical approximations,lacking the ability to design free-form metamaterial structures and optimize entire devices *** this work,we propose a hierarchical inverse design approach that combines a conventional effective refractive index based metamaterial structures design with a follow-up global topology *** empirical metamaterial grating coupler design based on effective refractive index engineering faces inaccurate index extraction and insufficient approximation of wavevector matching conditions,which deteriorates coupling efficiency,especially for fully-etched devices with the decreased tapering ***,a subsequent overall topology optimization step can well compensate for the negative effect of the shrinking device footprint to increase the efficiency of the metamaterial grating *** demonstrate a 23μm×10μm ultra-compact metamaterial grating coupler with single-stepetched to couple light between a fiber and a 500 nm single-mode silicon waveguide in the *** measurement shows an insertion loss of 3.17 dB and a 3 dB bandwidth of 77 nm,making it the smallest footprint device ever reported.

关键词： waveguide hierarchical inverse

Bioactivity of silk fibroin peptides on vascular endothelial cells

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Frontiers of Materials Science 2024年第1期18卷 85-94页

作者： Mengnan Dai Meng Li Peixuan Li Boyu Zhang Jianmei Xu Jiannan Wang National Engineering Laboratory for modern Silk College of Textile and Clothing EngineeringSoochow UniversityNo.199 Ren-ai RoadSuzhou Industrial ParkSuzhou 215123China

To determine the contribution of non-repetitive domains to the bioactivity of the heavy chain in silk fibroin(SF)macromolecules,a gene motif f(1)encoding this fragment and its multimers(f(4)and f(8))were biosynthesized from Escherichia coli *** on the positive application potential of SF materials for the vascular tissue engineering,this study focused on examining the active response of these polypeptides to vascular endothelial *** polypeptides F(1),F(4),and F(8)were separately grafted onto the surfaces of bioinert polyethylene terephthalate(PET)films,resulting in remarkable improvements in the spread and proliferation of human umbilical vein endothelial cells(HUVECs).Using the same grafting dose,the activity of cells on polypeptide-modified PET films enhanced with the increase of the molecular weight of those grafted polypeptides from F(1)to F(8).Meanwhile,the growth of cells on the surface of the alkaline-treated PET film was improved,indicating that the hydrophilicity of the surface material had influence on the growth of ***,on surfaces with the same water contact angle,the spread and proliferation activity of cells on PET films were significantly lower than those on polypeptide-modified PET films.

关键词： silk fibroin heavy chain non-repetitive fragment cytoactive endothelial cell