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Research on High-Velocity Impact Damage Monitoring Method of CFRP Based on Guided Wave

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Transactions of Nanjing University of Aeronautics and Astronautics 2024年第S1期41卷 60-69页

作者： WANG yang yang Xiaofei qiu lei YUAN Shenfang State Key Laboratory of Mechanics and Control for Aerospace Structures Research Center of Structural Health Monitoring and PrognosisNanjing University of Aeronautics and AstronauticsNanjing 210016P.R.China

Carbon fiber-reinforced polymer(CFRP)is widely used in aerospace *** kind of material may face the threat of high-velocity impact in the process of dedicated service,and the relevant research mainly considers the impact resistance of the material,and lacks the high-velocity impact damage monitoring research of *** solve this problem,a real high-velocity impact damage experiment and structural health monitoring(SHM)method of CFRP plate based on piezoelectric guided wave is *** results show that CFRP has obvious perforation damage and fiber breakage when high-velocity impact *** is also proved that guided wave SHM technology can be effectively used in the monitoring of such damage,and the damage can be reflected by quantifying the signal changes and damage index(DI).It provides a reference for further research on guided wave structure monitoring of high/hyper-velocity impact damage of CFRP.

关键词： guided waves structural health monitoring(SHM) carbon fiber reinforced polymer(CFRP) high-velocity impact

A low-power Bluetooth-based wireless sensor network and its global confliction-solving impact localization method

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Chinese Journal of Aeronautics 2024年第1期37卷 153-161页

作者： Yuanjia WANG lei qiu Qiyun XU Liming SHI College of Aerospace Engineering Nanjing University of Aeronautics and AstronauticsNanjing 210016China Department of Electrical and Electronic Engineering University of EdinburghEdinburgh EH89YLUK

During the whole service lifetime of aircraft structures with composite materials,impacts are inevitable and can usually cause severe but barely visible *** the occurrences of impact are random and unpredictable,it is a hotspot direction to develop an online impact monitoring system that can meet strict limitations of aerospace applications including small size,light weight,and low power ***(PZT)sensor,being able to generate impact response signals with no external power and cover a large-scale structure with only a small amount of them,is a promising ***,for real systems,networks with multiple nodes are normally required to monitor large-scale structures in a global way to identify any impact localization confliction,yet the existing studies are mostly evaluated with single nodes instead of ***,in this paper,based on a new low-power node designed,a Bluetooth-based digital impact monitoring PZT sensor network is proposed for the first time with its global confliction-solving impact localization *** of the system as a network are researched and analyzed on a complex real aircraft wing box for a global confliction-solving impact localization,showing a satisfying high accuracy.

关键词： Bluetooth-based low-power design Confliction-solving evaluation Complex composites Piezoelectric sensors Wireless impact monitoring network

Boron nitride silicone rubber composite foam with low dielectric and high thermal conductivity

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Chinese Journal of Chemical Engineering 2024年第4期68卷 224-230页

作者： Shuilai qiu Hang Wu Fukai Chu lei Song College of Safety and Ocean Engineering China University of Petroleum-BeijingBeijing 102249China State Key Laboratory of Fire Science University of Science and Technology of ChinaHefei 230026China

Silicone rubber(SR)is widely used in the field of electronic packaging because of its low dielectric *** this work,the porosity of the SR was improved,and the dielectric constant of the SR foam was reduced by adding expanded microspheres(EM).Then,the thermal conductivity of the system was improved by combining the modified boron nitride(f-BN).The results showed that after the f-BN was added,the dielectric constant and dielectric loss were much lower than those of pure ***-sized modified boron nitride(f-mBN)improved the dielectric and thermal conductivity of the SR foam better than that of nano-sized modified boron nitride(f-nBN),but f-nBN improved the volume resistivity,tensile strength,and thermal stability of the SR better than *** the mass ratio of f-mBN and fnBN is 2:1,the thermal conductivity of the SR foam reaches the maximum value of 0.808 W·m^(-1)·K^(-1),which is 6.5 times that before the *** heat release rate and fire growth index are the lowest,and the improvement in flame retardancy is mainly attributed to the high thermal stability and physical barrier of f-BN.

关键词： Foam Composites Dielectric properties Thermal conductivity Mechanical properties Flame retardant

A Bifunctional-Blocker-Aided Hybridization Chain Reaction Lighting-Up Self-calibrating Nanocluster Fluorescence for Reliable Nucleic Acid Detection

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Journal of Analysis and Testing 2024年第2期8卷 160-169页

作者： Dan Zhang Guobao Zhou Hongyan yang Yi Wang Lijun Shen Yuxuan qiu lei Li Longhua Guo College of Chemistry and Materials Science Zhejiang Normal UniversityJinhua321004China Jiaxing Key Laboratory of Molecular Recognition and Sensing College of BiologicalChemical Sciences and EngineeringJiaxing UniversityJiaxing314001China College of Life Sciences and Medicine Zhejiang Sci-Tech UniversityHangzhou314000China

In this work,we proposed a ratiometric silver nanoclusters(AgNCs)fluorescent assay by designing a bifunctional-blockeraided hybridization chain reaction(HCR).Hairpin probe 1(HP1)containing two special DNA fragments(5′-CAC CGC T-3′and 5′-ATT TGC CTT TTG GGG ACG GATA-3′)at two terminals creates a red-emitting AgNC nucleation sequence(rNS,5′-CAC CGC TAT TTG CCT TTT GGG GAC GGATA-3′).We found that the presence of a toehold fragment(5′-TGCCC-3′)in HP1 could silence the *** the addition of a target nucleic acid,HCR of HP1 and hairpin probe 2(HP2)could be initiated,resulting in the formation of long chain of DNA duplexes with multibranched *** the toehold fragment in HP1participated in generating duplexes,a strong emission of rNS-templated AgNCs was observed at 670 *** significantly,a bifunctional blocker was introduced not only to reduce the background red-emitting fluorescence but also to play as an internal green-emitting AgNCs nucleation *** the one hand,the blocker could increase the signal-to-noise-ratio of the constructed biosensor,and on the other hand,the blocker also helped to prepare ratiometric HCR-AgNCs assay with self-calibrating ability to strengthen its *** with the traditional HCR-AgNCs sensors,the developed ratiometric assay based on the bifunctional-blocker-aided HCR has higher reliability,which is important for the fabrication of biosensors in various fields for practical biosensing applications.

关键词： Ratiometric fluorescence Hybridization chain reaction Silver nanocluster Biosensor Bifunctional blocker

Vibration properties of Paulownia wood for Ruan sound quality using machine learning methods

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Journal of Forestry Research 2024年第5期35卷 216-222页

作者： yang yang College of Art and Design Harbin UniversityHarbin 150076People’s Republic of China College of Mechanical and Electrical Engineering Northeast Forestry UniversityHarbin 150040People’s Republic of China

As an important material for manufacturing resonant components of musical instruments,Paulownia has an important influence on the sound quality of *** this paper,a model for evaluating the sound quality of Ruan based on the vibration characteristics of wood is developed using machine learning ***,the selection of materials for Ruan manufacturing relies primarily on manually weighing,observing,striking,and listening by the instrument *** in scientific theory have hindered the quality of the finished *** this study,nine Ruans were manufactured,and a prediction model of Ruan sound quality was proposed based on the raw material information of *** of a total of 180 data sets,145 and 45 sets were chosen for training and validation,*** this paper,typical correlation analysis was used to determine the correlation between two single indicators in two adjacent pairwise combinations of the measured objects in each stage of the production process in *** vibra-tion characteristics of the wood were tested,and a model for predicting the evaluation of Ruan’s acoustic qualities was developed by measuring the vibration characteristics of the resonating plate *** acoustic quality of the Ruan sound board wood was evaluated and predicted using machine learning model generalized regression neural *** results show that the prediction of Ruan sound quality can be achieved using Matlab simulation based on the vibration characteristics of the soundboard *** the model-predicted values were compared with the tradi-tional predicted results,it was found that the generalized regression neural network had good performance,achieving an accuracy of 93.8%which was highly consistent with the experimental *** was concluded that the model can accurately predict the acoustic quality of the Ruan based on the vibration performance of the soundboards.

关键词： Sound quality Wood vibration performance Paulownia wood Machine learning methods

Extended finite element-based cohesive zone method for modeling simultaneous hydraulic fracture height growth in layered reservoirs

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第8期16卷 2960-2981页

作者： lei yang Baixi Chen Hopkins Extreme Materials Institute Johns Hopkins UniversityBaltimoreMD21218USA School of Civil Engineering The University of SydneyNSW2006Australia Department of Mechanical Engineering University of Wisconsin-Madison1513 University AvenueMadisonWI53706-1572USA Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina

In this study,a fully coupled hydromechanical model within the extended finite element method(XFEM)-based cohesive zone method(CZM)is employed to investigate the simultaneous height growth behavior of multi-cluster hydraulic fractures in layered porous reservoirs with modulus *** coupled hydromechanical model is first verified against an analytical solution and a laboratory ***,the fracture geometry(***,aperture,and area)and fluid pressure evolutions of multiple hydraulic fractures placed in a porous reservoir interbedded with alternating stiff and soft layers are investigated using the *** stress and pore pressure distributions within the layered reservoir during fluid injection are also *** simulation results reveal that stress umbrellas are easily to form among multiple hydraulic fractures’tips when propagating in soft layers,which impedes the simultaneous height *** is also observed that the impediment effect of soft layer is much more significant in the fractures suppressed by the preferential growth of adjoining *** that,the combined effect of in situ stress ratio and fracturing spacing on the multi-fracture height growth is presented,and the results elucidate the influence of in situ stress ratio on the height growth behavior depending on the fracture ***,it is found that the inclusion of soft layers changes the aperture distribution of outmost and interior hydraulic *** results obtained from this study may provide some insights on the understanding of hydraulic fracture height containment observed in filed.

关键词： Hydraulic fracturing Layered reservoir Simultaneous height growth In situ stress Fracture spacing Extended finite element method(XFEM) Cohesive zone method(CZM)

The Short-Duration Heavy Rainfall in Different Quadrants of Northeast China Cold Vortices

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Journal of Meteorological Research 2024年第2期38卷 321-338页

作者： lei yang Yongguang ZHENG Liaoning Meteorological Disaster Monitoring and Early Warning Center Shenyang 110166 National Meteorological Centre China Meteorological AdministrationBeijing 100081 China Meteorological Administration Tornado Key Laboratory Foshan 528315

The Northeast China cold vortex(NCCV)is one of the main synoptic-scale systems causing short-duration heavy rainfall(SDHR)in Northeast *** conditions(e.g.,water vapor,instability,and vertical wind shear)are known to be distinctly different over the four quadrants of NCCVs,rendering prediction of the SDHR related to NCCVs(NCCV_SDHR)more *** on 5-yr hourly rainfall observations from 3196 automatic weather stations and ERA5 reanalysis data,10,232 NCCV_SDHR events were identified and divided into four quadrant groups according to their relative position to the center of the NCCV(CVC).The results show that the southeast quadrant features the highest frequency of SDHR,with stronger intensity,longer duration,and wider coverage;and the SDHR in different quadrants presents different formation mechanisms and varied temporal evolution.A new coordinate system is established relative to the CVC that uses the CVC as the origin and the radius of the NCCV(r CV)as the unit *** this new coordinate system,all of the NCCV_SDHR events in the 5-yr study period are *** is found that the occurrence frequency of NCCV_SDHR initially increases and then decreases with increasing distance from the *** highest frequency occurs mainly between 0.8 and 2.5 times r CV from the CVC in the southeast *** can be attributed to the favorable conditions,such as convergence of the low-level shear line and abundant water vapor,which are concentrated in this ***,high-frequency NCCV_SDHR larger than 50 mm(NCCV_SDHR50)is observed to be closer to the *** NCCV_SDHR50occurs,the NCCV is in closer proximity to the subtropical high,resulting in stronger low-level convergence and more abundant water ***,there are lower lifting condensation levels and stronger 0-6-and 0-1-km vertical wind shears in these *** findings provide a valuable reference for more accurate prediction of NCCV_SDHR.

关键词： Northeast China cold vortex short-duration heavy rainfall statistical characteristics environmental conditions

Pharmacological Effects of Botanical Drugs on Myocardial Metabolism in Chronic Heart Failure

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Chinese Journal of Integrative Medicine 2024年第5期30卷 458-467页

作者： HU Yu-xuan qiu Sheng-lei SHANG Ju-ju WANG Zi LAI Xiao-lei Beijing Hospital of Traditional Chinese Medicine Capital Medical UniversityBeijing 100010China

Although there have been significant advances in the treatment of heart failure in recent years,chronic heart failure remains a leading cause of cardiovascular disease-related *** studies have found that targeted cardiac metabolic remodeling has good potential for the treatment of heart ***,most of the drugs that increase cardiac energy are still in the theoretical or testing *** research has found that botanical drugs not only increase myocardial energy metabolism through multiple targets but also have the potential to restore the balance of myocardial substrate *** this review,we summarized the mechanisms by which botanical drugs(the active ingredients/formulas/Chinese patent medicines)improve substrate utilization and promote myocardial energy metabolism by activating AMP-activated protein kinase(AMPK),peroxisome proliferator-activated receptors(PPARs)and other related *** the same time,some potential protective effects of botanical drugs on myocardium,such as alleviating oxidative stress and dysbiosis signaling,caused by metabolic disorders,were briefly discussed.

关键词： botanical drugs chronic heart failure myocardial metabolism pharmacological effects review

Thin-walled and large-sized magnesium alloy die castings for passenger car cockpit:Application,materials,and manufacture

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China Foundry 2024年第5期21卷 525-545页

作者： lei Zhan Yu-meng Sun yang Song Chun-hua Kong Kai Ma Bai-xin Dong Hong-yu yang Shi-li Shu Feng qiu School of Automotive Engineering Jilin Communication PolytechnicChangchun 130012China Key Laboratory of Automobile Materials of Ministry of Education School of Materials Science and EngineeringNanling CampusJilin UniversityChangchun 130025China

In order to effectively reduce energy consumption and increase range mile,new energy vehicles represented by Tesla have greatly aroused the application of integrated magnesium(Mg)alloy die casting technology in ***,the application of Mg alloys in automobiles,especially in automotive cockpit components,is quite extensive,while it has almost disappeared for a period of time due to its relatively high cost,causing a certain degree of information loss in the application technology of Mg alloy parts in *** rapid development of automotive technology has led to a higher requirement for the automotive components compared with those traditional ***,whatever the components themselves,or the Mg alloy materials and die casting process have to face an increasing challenge,needing to be *** addition,owing to its high integration characteristics,the application of Mg alloy die casting technology in large-sized and thin-walled automotive parts has inherent advantages and needs to be expanded ***,it necessitates exploring advance Mg alloys and new product structures and optimizing die casting *** article summarizes and analyzes the development status of thin-walled and large-sized die casting Mg alloy parts in passenger car cockpit and corresponding material selection methods,die casting processes as well as mold design ***,this work will aid researchers in establishing a comprehensive understanding of the manufacture of thin-walled and large-sized die casting Mg alloy parts in automobile *** will also assist them in developing new Mg alloys with improved comprehensive performance and new processes to meet the high requirements for die casting automotive components.

关键词： Mg alloys thin wall large size automotive part die casting