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Chinese Journal of Mechanical Engineering 2024年第1期37卷 309-320页

作者： Yao Jia Jianping Lai Jiaxin Yu Huimin Qi yafeng.zhang Hongtu He Key Laboratory of Testing Technology for Manufacturing Process in Ministry of Education State Key Laboratory of Environment-Friendly Energy MaterialsSouthwest University of Science and TechnologyMianyang 621010China

Titanium alloys are excellent structural materials in engineering fields,but their poor tribological properties limit their further applications.Electroless plating is an effective method to enhance the tribological performance of alloys,but it is difficult to efficiently apply to titanium alloys,due to titanium alloy’s strong chemical activity.In this work,the electroless Nickel-Boron(Ni-B)coating was successfully deposited on the surface of titanium alloy(Ti-6AL-4V)via a new pre-treatment process.Then,linearly reciprocating sliding wear tests were performed to evaluate the tribological behaviors of titanium alloy and its electroless Ni-B coatings.It was found that the Ni-B coatings can decrease the wear rate of the titanium alloy from 19.89×10^(−3)mm^(3)to 0.41×10^(−3)mm^(3),which attributes to the much higher hardness of Ni-B coatings.After heat treatment,the hardness of Ni-B coating further increases corresponding to coating crystallization and hard phase formation.However,heat treatment does not improve the tribological performance of Ni-B coating,due to the fact that higher brittleness and more severe oxidative wear exacerbate the damage of heat-treated coatings.Furthermore,the Ni-B coatings heat-treated both in air and nitrogen almost present the same tribological performance.The finding of this work on electroless coating would further extend the practical applications of titanium alloys in the engineering fields.

关键词： Electroless coating Titanium alloy Tribology Wear Heat treatment Nanoindentation

Peptide-RNA complexation-induced fluorescence“turn on”displacement assay for the recognition of small ligands targeting HIV-1 RNA

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Journal of Pharmaceutical Analysis 2022年第6期12卷 923-928页

作者： Liang Qi Jiayun zhang Ying Gao Pin Gong Chengyuan Liang Yao Su Qiao Zeng yafeng.zhang Department of Pharmacy School of Food and Biological EngineeringShaanxi University of Science&TechnologyXi'an710021China Xi'an Institute for Food and Drug Control Xi'an710054China

The regulator of expression of virion(Rev)protein binds specifically to the Rev-responsive element(RRE)RNA in order to regulate the expression of the human immunodeficiency virus(HIV)-1 genes.Fluorescence indicator displacement assays have been used to identify ligands that can inhibit the ReveRRE interaction;however,the small fluorescence indicators cannot fully replace the Rev peptide or protein.As a result,a single rhodamine B labeled Rev(RB-Rev)model peptide was utilized in this study to develop a direct and efficient ReveRRE inhibitor screening model.Due to photon-induced electron transfer quenching of the tryptophan residue on the RB fluorophore,the fluorescence of RB in Rev was weakened and could be dramatically reactivated by interaction with RRE RNA in ammonium acetate buffer(approximately six times).The interaction could reduce the electron transfer between tryptophan and RB,and RRE could also increase RB fluorescence.The inhibitor screening model was evaluated using three known positive ReveRRE inhibitors,namely,proflavin,6-chloro-9-[3-(2-chloroethylamino)propylamino]-2-methoxyacridine(ICR 191),and neomycin,as well as a negative drug,arginine.With the addition of the positive drugs,the fluorescence of the ReveRRE decreased,indicating the displacement of RB-Rev.This was confirmed using atomic force microscopy(AFM)and the fluorescence was essentially unaffected by the addition of arginine.The results demonstrated that RB-Rev can be used as a fluorescent probe for recognizing small ligands that target RRE RNA.The ReveRRE inhibitor screening model offers a novel approach to evaluating and identifying long-acting Rev inhibitors.

关键词： RRE RNA Rev protein Fluorescence enhancement Ligand-RNA interaction Drug screening

Optimal Design of Rectification Circuit in Electronic Circuit Fault Self-repair Based on EHW and RBT

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Chinese Journal of Electronics 2018年第1期27卷 93-101页

作者： zhang Junbin CAI Jinyan MENG yafeng Department of Electronic and Optical Engineering Mechanical Engineering College Hypervelocity Aerodynamics Institute China Aerodynamics Research & Development Center

Reliability of traditional electronic circuit is improved mainly by redundant fault-tolerant technology with large hardware resource consumption and limited fault self-repair capability. In complicated environment,electronic circuit faults appear easily. If on-site immediate repair is not implemented, normal running of electronic system will be directly affected. In order to solve these problems, Evolvable hardware(EHW) technology is widely used. The conventional EHW has some bottlenecks.The optimal design of Rectification circuit(RTC) is further researched on the basis of the previously proposed fault self-repair based on EHW and Reparation balance technology(RBT). Fault sets are selected by fault danger degree and fault coverage rate. The optimal designed RTC can completely repair faults in the fault set. Simulation results prove that it has higher self-repair capability and less hardware resource.

关键词： Evolvable hardware(EHW) Fault self repair Reparation balance technology(RBT) Rectification circuit(RTC) Optimal design Fault coverage

Optimal design of RTCs in digital circuit fault self-repair based on global signal optimization

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Chinese Journal of Aeronautics 2016年第6期29卷 1774-1787页

作者： zhang Junbin Cai Jinyan Meng yafeng Department of Electronic and Optical Engineering Mechanical Engineering College

Since digital circuits have been widely and thoroughly applied in various fields, electronic systems are increasingly more complicated and require greater reliability. Faults may occur in electronic systems in complicated environments. If immediate field repairs are not made on the faults, electronic systems will not run normally, and this will lead to serious losses. The traditional method for improving system reliability based on redundant fault-tolerant technique has been unable to meet the requirements. Therefore, on the basis of(evolvable hardware)-based and(reparation balance technology)-based electronic circuit fault self-repair strategy proposed in our preliminary work, the optimal design of rectification circuits(RTCs) in electronic circuit fault self-repair based on global signal optimization is deeply researched in this paper. First of all, the basic theory of RTC optimal design based on global signal optimization is proposed. Secondly, relevant considerations and suitable ranges are analyzed. Then, the basic flow of RTC optimal design is researched. Eventually, a typical circuit is selected for simulation verification, and detailed simulated analysis is made on five circumstances that occur during RTC evolution. The simulation results prove that compared with the conventional design method based RTC, the global signal optimization design method based RTC is lower in hardware cost, faster in circuit evolution, higher in convergent precision, and higher in circuit evolution success rate. Therefore, the global signal optimization based RTC optimal design method applied in the electronic circuit fault self-repair technology is proven to be feasible, effective, and advantageous.

关键词： Evolutionary algorithm Evolvable hardware Fault self-repair Optimal design Reparation balance technology

Facile fabrication of superior antibacterial cotton fabric based on ZnO nanoparticles/quaternary ammonium salts hybrid composites and mechanism study

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Frontiers of Materials Science 2023年第2期17卷 105-120页

作者： Yechen Hu Lin zhang yafeng.Huang Xiufang Chen Fengtao Chen Wangyang Lu National Engineering Lab for Textile Fiber Materials&Processing Technology(Zhejiang) Zhejiang Sci-Tech UniversityHangzhou 310018China

In the research for the safe and efficiently antibacterial cotton fabrics to minimize risk for human health,an organic–inorganic hybrid material of ZnO nanoparticles(NPs)and quaternary ammonium salt(QAS)was employed to modify cotton fabrics by a dipping–padding–drying method.The synergistic effects of ZnO NPs and QAS on the structure and antibacterial properties of cotton fabrics were studied in detail.Results displayed that the QAS and ZnO NPs were immobilized firmly in cotton fabric by the formation of chemical covalent bonds and silica gel structure.ZnO/QAS/cotton had a good inhibitory effect on the growth of E.coli and S.aureus,with superior antibacterial efficiency of>99.99%.ZnO/QAS/cotton preserved good mechanical property,water absorbability,and limpness.We also provided a detailed analysis of antibacterial mechanism for the hybrid materials.The contact mechanism and the Zn2+release were considered as the main mechanisms for the ZnO/QAS/cotton,while the reactive oxygen species(ROS)generation only had a little contribution to the antibacterial activity.In short,the excellent integrated properties endowed the hybrid cotton fabrics as potential application in many fields,like healthcare,food packaging.

关键词： ZnO quaternary ammonium salt organic-inorganic hybrid material antibacterial mechanism

Review on application progress of federated learning model and security hazard protection

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Digital Communications and Networks 2023年第1期9卷 146-158页

作者： Aimin Yang Zezhong Ma Chunying zhang Yang Han Zhibin Hu Wei zhang Xiangdong Huang yafeng.Wu Hebei Engineering Research Center for the Intelligentization of Iron Ore Optimization and Ironmaking Raw Materials Preparation Processes North China University of Science and TechnologyTangshanHebeiChina Hebei Key Laboratory of Data Science and Application North China University of Science and TechnologyTangshanHebeiChina The Key Laboratory of Engineering Computing in Tangshan City North China University of Science and TechnologyTangshanHebeiChina Tangshan Intelligent Industry and Image Processing Technology Innovation Center North China University of Science and TechnologyTangshanHebeiChina College of Science North China University of Science and TechnologyTangshanHebeiChina College of Artificial Intelligence North China University of Science and TechnologyTangshanHebeiChina

Federated learning is a new type of distributed learning framework that allows multiple participants to share training results without revealing their data privacy.As data privacy becomes more important,it becomes difficult to collect data from multiple data owners to make machine learning predictions due to the lack of data security.Data is forced to be stored independently between companies,creating“data silos”.With the goal of safeguarding data privacy and security,the federated learning framework greatly expands the amount of training data,effectively improving the shortcomings of traditional machine learning and deep learning,and bringing AI algorithms closer to our reality.In the context of the current international data security issues,federated learning is developing rapidly and has gradually moved from the theoretical to the applied level.The paper first introduces the federated learning framework,analyzes its advantages,reviews the results of federated learning applications in industries such as communication and healthcare,then analyzes the pitfalls of federated learning and discusses the security issues that should be considered in applications,and finally looks into the future of federated learning and the application layer.

关键词： Data silos Machine learning Federated learning Privacy protection Learning framework

Intrastorm stemflow variability of a xerophytic shrub within a water-limited arid desert ecosystem of northern China

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Research in Cold and Arid Regions 2017年第5期9卷 495-502页

作者： yafeng.zhang XinPing Wang YanXia Pan Rui Hu Shapotou Desert Research and Experiment Station Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Lanzhou Gansu 730000 China

An increasing number of studies in recent years has elucidated distinguishable effects of stemflow on hydrology and biogeochemistry within a variety of ecosystems.Nonetheless,no known studies have investigated the temporal variability of stemflow volume within discrete rainfall events for xerophytic shrubs.Here,stemflow was monitored at 5-min intervals using a tipping-bucket rain gage during the 2015 growing season for a xerophytic shrub(Caragana korshinskii)within a water-limited arid desert ecosystem of northern China.We characterized the stemflow temporal variability,along with rainfall,and found the temporal heterogeneity of rainfall clearly affected the timing of stemflow inputs into basal soil within discrete rainfall events.The rainfall threshold value for stemflow generation is not a constant value but a range(0.6~2.1 mm,with an average of 1.1 mm)across rainfall events and is closely associated with the antecedent dry period.Time lags existed between the onset of rainfall and the onset of stemflow,and between rainfall peaks and stemflow peaks.Our findings are expected to be helpful for an improved process-based understanding of the temporal stemflow yield of xerophytic shrubs within water-limited arid desert ecosystems.

关键词： stemflow temporal variability xerophytic shrub antecedent dry period time lag

Nutrient enrichment driven by canopy rainfall redistribution:Mechanism,quantification,and pattern

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Science China Earth Sciences 2024年第5期67卷 1529-1544页

作者： Chuan YUAN Xiaoping YUE yafeng.zhang Yu zhang Yanting HU Qiang TANG Li GUO Shuai WANG Xingwu DUAN Wenhua XIANG Xiaohua WEI Xiaoyan LI College of Forestry and Biotechnology Zhejiang A&F UniversityHangzhou 311300China Chongqing Jinfo Mountain Karst Ecosystem National Observation and Research Station School of Geographical SciencesSouthwest UniversityChongqing 400715China Shapotou Desert Research and Experiment Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China School of Geographical Sciences Hebei Normal UniversityShijiazhuang 050024China Faculty of Life Science and Technology Central South University of Forestry and TechnologyChangsha 410004China State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu 610065China State Key Laboratory of Earth Surface Processes and Resource Ecology Faculty of Geographical ScienceBeijing Normal UniversityBeijing 100875China Yunnan Key Laboratory of Soil Erosion Prevention and Green Development Institute of International Rivers and Eco-securityYunnan UniversityKunming 650091China Department of Earth Environmental and Geographic SciencesUniversity of British Columbia(Okanagan)KelownaBritish Columbia V1V 1V7Canada

Vegetation canopies intercept and redistribute rainfall into throughfall and stemflow,which transfer substantial amounts of elements into the soil,influencing soil microbial community,plant survival,and plant community succession.Despite advancements in ecohydrological research,the implication of nutrient enrichment resulting from this redistribution of rainfall by canopies remains largely unexplored.To address this gap,we conducted a systematic review of 1020 papers published between 2000 and 2022,gathering data on nutrient concentration and enrichment for critical ions(including K^(+),Na^(+),Ca^(2+),Mg^(2+),NH_(4)^(+),Cl^(-),NO_(3)^(-)and SO_(4)^(2-))from the Web of Science and Chinese Knowledge Infrastructure databases.We aimed to synthesize the mechanisms,quantify the enrichments,and identify global patterns of nutrient enrichment in stemflow and throughfall across climate zones,and vegetation types and ecosystems.The results of this study indicate that stemflow exhibits,on average,2.1times greater ion concentration(6.13 mg L^(-1))compared to throughfall.In particular,among the investigated ions,SO_(4)^(2-)(12.45and 6.32 mg L^(-1))for stemflow and throughfall,respectively,and Cl^(-)(9.21 and 4.81 mg L^(-1))exhibit the highest concentrations in both rainfall redistribution components,while K^(+)(13.7 and 5.8)and Mg^(2+)(5.6 and 2.8)have the highest enrichment factors.Across climate zones,throughfall and stemflow show the lowest ion concentrations but the highest enrichment factors in extremely humid regions.Along the temperature gradient,ion concentrations are the highest in cold climates with no clear patterns observed for enrichment factors with increasing temperature.In addition,shrubs,conifers,mixed forests,and artificial ecosystems demonstrate enrichment factors 1.1 to 3.0 times greater than those of trees,broad-leaved plants,pure forests,and natural ecosystems.These findings emphasize the need for increased attentions to artificial ecosystems,such as urban and agricultural ecosystems,which often received

关键词： Ecohydrology Rainfall redistribution Nutrients transport Enrichment characteristics Climate zones

Unmanned aerial vehicle strike on a flat plate:Tests and numerical simulations

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Chinese Journal of Aeronautics 2023年第4期36卷 286-298页

作者： Jun LIU Chi CHEN Jingyu YU Jian LI Zhuguo zhang yafeng.WANG Yulong LI School of Aeronautics Northwestern Polytechnical UniversityXi’an 710072China AVIC(Chengdu)UAV System Co. LtdChengdu 611731China Shanghai Aircraft Airworthiness Certification Center of CAAC Shanghai 200335China China Aircraft Strength Research Institute Xi’an 710065China

The incursion of Unmanned Aerial Vehicles(UAVs)into airports often occurs due to the popularity of drones,which may lead to a threat to aircraft flight safety.Therefore,estimating the dynamic impact load caused by drone strikes is essential.This paper proposes a test method with high precision and low cost involving launching of a UAV to impact a flat plate specimen by using an air gun.The test results of UAVs impacting flat plates at different impact velocities,such as the UAV dam-age deformation captured by a high-speed camera and strain vs time dynamic response curves of plates,were obtained and analysed.At the same time,a corresponding numerical simulation was car-ried out by using the explicit finite element software LS-DYNA.The predicted damage to the UAV and strain on the flat plate during the strike process were compared with the test results.The overall trend of the simulation results is in good agreement with the test results,at least for the first three mil-liseconds of the event.This shows that the numerical simulation model established in this paper is rea-sonable.The UAV numerical method established in the present paper can be used to carry out numerical simulations and evaluations of the collision safety of UAVs against large aircraft and high-value ground targets.The results show that the local deformation of the impacted target is uneven due to the distribution of concentrated mass components such as motors,battery,and camera.As the impact velocity of the UAV increases,all parts of the UAV are seriously damaged and basically in a fragmented state,and the battery is greatly deformed.The interaction between the UAV and the flat plate specimen is approximately 2.7 ms,and the UAV numerical simulation model established in this paper can well simulate the real UAV impact process.

关键词： Air gun test Dynamic response Impact damage LS-DYNA UAV