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Laser cutting of thermoplastic film:Mechanism and processing technology

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Science China(Technological Sciences) 2022年第9期65卷 2068-2078页

作者： WU CongYi rong YouMin huang yu ZHANG GuoJun State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

The mechanism of ultraviolet(UV) nanosecond laser cutting of thermoplastic films and the influence of process parameters on process quality are systematically discussed.The photothermal effect plays a dominant role in the interaction between the UVnanosecond laser and thermoplastic materials.In this photothermal reaction,a heat source with the focal point as the core is formed,around which a thermal carbonization layer,a thermal melting layer,and a thermal expansion layer are formed in order from the inside to the outside.Among them,the thermal carbonization layer is not prevalent,and the thermal melting layer and thermal expansion layer are prevalent.The process quality can be adjusted by adjusting the cutting speed,the laser power,and the repetition number of cuts to regulate the process of heat generation and heat dissipation.In the effective range,the faster the cutting speed and the lower the laser power,the smaller the kerf width and heat-affected zone(HAZ) width.Within a certain range,the depth of kerf can be increased by increasing the repetition number of cuts.

关键词： laser cutting thermoplastic film mechanism process parameters

Approach of water-salt regulation using micro-sprinkler irrigation in two coastal saline soils

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Water Science and Engineering 2023年第1期16卷 106-112页

作者： Lin-lin Chu yu Zhu Ling Xiong Rong-yu Huang Yao-hu Kang: Zhan-peng Liu Xiao-ming Geng College of Agricultural Science and Engineering Hohai UniversityNanjing 210098China Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Nanjing Jiangdi Land Development Consulting Service Co. LtdNanjing 210036China Nanjing Qinhuai River Management Office Nanjing 210012China

This study aimed to investigate whether saline silt and sandy loam coastal soils could be reclaimed by micro-sprinkler irrigation.The experiments were run using moderately salt-tolerant tall fescue grass.Micro-sprinkler irrigation in three stages was used to regulate soil matric potential at a 20-cm soil depth.Continued regulation of soil water and salt through micro-sprinkler irrigation consistently resulted in an increasingly large low-salinity region.The application of the three stages of soil wateresalt regulation resulted in an absence of salt accumulation throughout the soil profile and the conversion of highly saline soils into moderately saline soils.There were increases in the plant height,leaf width,leaf length,and tiller numbers of tall fescue throughout the leaching process.The results showed that micro-sprinkler irrigation in three soil water and salt regulation stages can be used to successfully cultivate tall festuca in highly saline coastal soil.This approach achieved better effects in sandy loam soil than in silt soil.Tall fescue showed greater survival rates in sandy loam soil due to the rapid reclamation process,whereas plant growth was higher in silt soil because of effective water conservation.In sandy loam,soil moisture should be maintained during soil reclamation,and in silt soil,soil root-zone environments optimal for the emergence of plants should be quickly established.Micro-sprinkler irrigation can be successfully applied to the cultivation of tall fescue in coastal heavy saline soils under a three-stage soil wateresalt regulation regime.

关键词： Coastal saline soils Micro-sprinkler irrigation Salt leaching Tall fescue Wateresalt regulation

Lattice Boltzmann study on the effects of surface nanostructure on wettability with application in laser scanning fabrication of superhydrophobic surfaces

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Science China(Technological Sciences) 2023年第11期66卷 3197-3205页

作者： huang Hao GUO MingHui WU CongYi rong YouMin huang yu ZHANG GuoJun State Key Laboratory of Intelligent Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

Nanostructured surfaces with dimensions on a scale of a few millimeters exhibit remarkable hydrophobicity.The geometry of these nanostructures considerably affects their wettability.However,determining the optimal geometry is challenging due to the abundance of geometry parameters and the difficulty in numerically describing their effects on wettability at the mesoscopic scale.In addition,the fabrication of nanostructured surfaces with precise geometries is challenging.We establish a lattice Boltzmann method(LBM)model to address these challenges.We use the model to gain mesoscopic insights into the interaction between droplets and nanostructures.Our model can accurately reproduce contact angles(CAs)on various nanostructured surfaces and enables investigation of the effects of nanostructure geometry on wettability.We optimize the geometry of the nanostructures using the insights provided by the LBM model on the wettability mechanisms.Our analysis indicates that cones with dimensions of 40μm in width and 33μm in height exhibit the highest hydrophobicity.We successfully fabricate a superhydrophobic surface with the desired geometry via laser scanning,achieving a CA of 163°.We believe that this approach,which combines the LBM model and laser manufacturing,will enable a better understanding of the wettability mechanism and provide a high-performance approach for fabricating superhydrophobic surfaces.

关键词： wettability lattice Boltzmann method nanostructure laser scanning

Revealing the interaction mechanism of pulsed laser processing with the application of acoustic emission

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Frontiers of Optoelectronics 2023年第2期16卷 91-101页

作者： Weinan Liu Youmin rong Ranwu Yang Congyi Wu Guojun Zhang yu huang State Key Lab of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China School of Mechanical Science and Engineering Huazhong University of Science and TechnologyWuhan 430074China

The mechanisms of interaction between pulsed laser and materials are complex and indistinct,severely infuencing the stability and quality of laser processing.This paper proposes an intelligent method based on the acoustic emission(AE)technique to monitor laser processing and explore the interaction mechanisms.The validation experiment is designed to perform nanosecond laser dotting on foat glass.Processing parameters are set diferently to generate various outcomes:ablated pits and irregular-shaped cracks.In the signal processing stage,we divide the AE signals into two bands,main and tail bands,according to the laser processing duration,to study the laser ablation and crack behavior,respectively.Characteristic parameters extracted by a method that combines framework and frame energy calculation of AE signals can efectively reveal the mechanisms of pulsed laser processing.The main band features evaluate the degree of laser ablation from the time and intensity scales,and the tail band characteristics demonstrate that the cracks occur after laser dotting.In addition,from the analysis of the parameters of the tail band very large cracks can be efciently distinguished.The intelligent AE monitoring method was successfully applied in exploring the interaction mechanism of nanosecond laser dotting foat glass and can be used in other pulsed laser processing felds.

关键词： Laser dotting Acoustic emission Monitoring Laser ablation Cracks

Metal-organic frameworks bonded with metal N-heterocyclic carbenes for efficient catalysis

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National Science Review 2022年第6期9卷 64-73页

作者： Chang He Jun Liang yu-huang Zou Jun-Dong Yi yuan-Biao huang rong Cao State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences University of Chinese Academy of Sciences Science and Technology Innovation Laboratory for Optoelectronic Information of China

Metal N-heterocyclic carbenes(M-NHCs) on the pore walls of a porous metal-organic framework(MOF)can be used as active sites for efficient organic catalysis. Traditional approaches that need strong alkaline reagents or insoluble Ag2O are not, however, suitable for the incorporation of NHCs on the backbones of MOFs because such reagents could destroy their frameworks or result in low reactivity. Accordingly,development of facile strategies toward functional MOFs with covalently bound M-NHCs for catalysis is needed. Herein, we describe the development of a general and facile approach to preparing MOFs with covalently linked active M-NHC(M = Pd, Ir) single-site catalysts by using a soluble Ag salt AgOC(CF3)3as the source and subsequent transmetalation. The well-defined M-NHC-MOF(M = Pd, Ir) catalysts obtained in this way have shown excellent catalytic activity and stability in Suzuki reactions and hydrogen transfer reactions. This provides a general and facile strategy for anchoring functional M-NHC single-site catalysts onto functionalized MOFs for different reactions.

关键词： metal-organic framework N-heterocyclic carbene MIL-101 Suzuki reaction transfer hydrogenation

Characterization of the pheromone receptors in Mythimna loreyi reveals the differentiation of sex pheromone recognition in Mythimna species

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Insect Science 2024年第1期31卷 173-185页

作者： Chan Wang Lei Liu Tian-yu huang yu Zhang Yang Liu Gui-rong Wang State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijingChina Guangdong Laboratory of Lingnan Modern Agriculture ShenzhenGenome Analysis Laboratory of the Ministry of AgricultureAgricultural Genomics Institute at ShenzhenChinese Academy of Agricultural SciencesShenzhenChina School of Forestry Northeast Forestry UniversityHarbinChina Key Laboratory of Biohazard Monitoring Green Prevention and Control for Artificial GrasslandMinistry of Agriculture and Rural AffairsInstitute of Grassland Research of Chinese Academy of Agricultural SciencesInner Mongolia HohhotChina

Pheromone receptors(PRs)are key proteins in the molecular mechanism of pheromone recognition,and exploring the functional differentiation of PRs between closely related species helps to understand the evolution of moth mating systems.Pheromone components of the agricultural pest Mythimna loreyi have turned into(Z)-9-tetradecen-1-yl acetate(Z9-14:OAc),(Z)-7-dodecen-1-yl acetate(Z7-12:OAc),and(Z)-11-hexadecen-1-yl acetate,while the composition differs from that of M.separata in the genus Mythimna.To understand the molecular mechanism of pheromone recognition,we sequenced and analyzed antennal transcriptomes to identify 62 odorant receptor(OR)genes.The expression levels of all putative ORs were analyzed using differentially expressed gene analysis.Six candidate PRs were quantified and functionally characterized in the Xenopus oocytes system.MlorPR6 and MlorPR3 were determined to be the receptors of major and minor components Z9-14:OAc and Z7-12:OAc.MlorPR1 and female antennae(FA)-biased MlorPR5 both possessed the ability to detect pheromones of sympatric species,including(Z,E)-9,12-tetradecadien-1-ol,(Z)-9-tetradecen-1-ol,and(Z)-9-tetradecenal.Based on the comparison of PR functions between M.loreyi and M.separata,we analyzed the differentiation of pheromone recognition mechanisms during the evolution of the mating systems of 2 Mythimna species.

关键词： antennal transcriptome Mythimna loreyi pheromone receptor sex pheromone Xenopus oocyte

Unpredictability of Digital Twin for Connected Vehicles

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China Communications 2023年第2期20卷 26-45页

作者： Xiaoxu Wang Zeyin huang Songmiao Zheng rong yu Miao Pan School of Automation Guangdong University of TechnologyGuangzhou 510006China Electrical and Computer Engineering Department University of HoustonHoustonTX 77004USA

Digital twin is an essential enabling technology for 6G connected vehicles.Through highfidelity mobility simulation,digital twin is expected to make accurate prediction about the vehicle trajectory,and then support intelligent applications such as safety monitoring and self-driving for connected vehicles.However,it is observed that even if a digital twin model is perfectly derived,it might still fail to predict the trajectory due to tiny measurement noise or delay in the initial vehicle locations.This paper aims at investigating the sources of unpredictability of digital twin.Take the car-following behaviors in connected vehicles for case study.The theoretical analysis and experimental results indicate that the predictability of digital twin naturally depends on its system complexity.Once a system enters a complex pattern,its longterm states are unpredictable.Furthermore,our study discloses that the complexity is determined,on the one hand,by the intrinsic factors of the target physical system such as the driver’s response sensitivity and delay,and on the other hand,by the crucial parameters of the digital twin system such as the sampling interval and twining latency.

关键词： digital twin connected vehicles unpredictability complexity

Privacy-Preserving Incentive Mechanism for Platoon Assisted Vehicular Edge Computing with Deep Reinforcement Learning

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China Communications 2022年第7期19卷 294-309页

作者： Xumin huang yupei Zhong yuan Wu Peichun Li rong yu School of Automation Guangdong University of TechnologyGuangzhou 510006China The State Key Laboratory of Internet of Things for Smart City University of MacaoTaipaMacaoChina Department of Computer and Information Science University of MacaoTaipaMacaoChina

Platoon assisted vehicular edge computing has been envisioned as a promising paradigm of implementing offloading services through platoon cooperation.In a platoon,a vehicle could play as a requester that employs another vehicles as performers for workload processing.An incentive mechanism is necessitated to stimulate the performers and enable decentralized decision making,which avoids the information collection from the performers and preserves their privacy.We model the interactions among the requester(leader)and multiple performers(followers)as a Stackelberg game.The requester incentivizes the performers to accept the workloads.We derive the Stackelberg equilibrium under complete information.Furthermore,deep reinforcement learning is proposed to tackle the incentive problem while keeping the performers’information private.Each game player becomes an agent that learns the optimal strategy by referring to the historical strategies of the others.Finally,numerical results are provided to demonstrate the effectiveness and efficiency of our scheme.

关键词： vehicular edge computing Stackelberg game deep reinforcement learning

Dexmedetomidine as an adjunct to peripheral nerve blocks in pediatric patients

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World Journal of Pediatrics 2022年第4期18卷 251-262页

作者： Jing Yang yu Cui rong Cao Qing-Hua huang Qian-Qian Zhang Department of Anesthesiology The Affiliated HospitalSchool of MedicineUESTC Chengdu Women’s&Children’s Central HospitalNo.1617Riyue AvenueQingyang DistrictChengdu 610091China

Background Combining local anesthetics with dexmedetomidine(DEX)for nerve blocks has been tested and confirmed as an alternative technique to strengthen analgesia in adults,but the evidence supported this proposal in pediatrics was not convincing enough.Thus,we intend to conduct a meta-analysis to make an appraisal of the effects of DEX as a local anesthetic adjuvant on peripheral nerve blocks in children.Methods The analysis has been registered on https://www.***.york.***.uk/prospero/with the registration number CRD42021254029 on June 10th,2021.PubMed,Ovid MEDLINE,Embase and Cochrane central register were searched for the randomized controlled trials(RCTs)that are relevant to child/pain/DEX or block up to April 30,2021.Results Eight RCTs were included for data analysis.The pooled results showed a significantly reduced number of patients who required postoperative analgesics within DEX groups[odds ratio=0.1,95%confidence interval(CI)0.03-0.32,P<0.001].And DEX significantly prolonged the duration of analgesia of local anesthetics in the meantime[standardized mean difference(SMD)=4.93,95%CI 3.02-6.83,P<0.001].Nevertheless,adding DEX as an adjunct to local anesthetics would significantly decrease heart rate(SMD=-0.95,95%CI-1.45 to-0.45,P<0.001)and increase sedation score(SMD=1.6,95%CI 0.53-2.66,P=0.003)simultaneously.Conclusions Adding DEX as an adjunct to peripheral nerve blocks can prolong analgesia until postoperative 8 hours in pediatric patients.However,the benefits should be weighed against the increasing risk of bradycardia and sedation in critical children.

关键词： Block Child Dexmedetomidine Pain