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Unmanned autonomous air-to-air refueling intelligent docking technology

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Chinese Journal of Aeronautics 2024年第5期37卷 1-5页

作者： Peng LIN Yakun HE Yuanze CHEN Chinese aeronautical Establishment Beijing 100029China

Unmanned autonomous Air-to-Air Refueling(AAR)capability is the key guarantee to support the distant-field,high-intensity and durable operations of the penetration counterair combat *** the future,the long-range unmanned reconnaissance and attack platform can reach the maximum flight range requirement through *** present,large transport aircraft platforms in China are still equipped with probe-and-drogue systems,and the refueling mode is gradually changing from manned to unmanned autonomous *** docking process is the riskiest and most important part,and there are strict safety,precision,and efficiency requirements for refueling operation,especially during close-distance docking and formation maintenance *** this paper,five issues that need to be solved to achieve autonomous AAR docking are *** this basis,five key technology development needs are proposed to solve these engineering ***,some prospects are given.

关键词： Air-to-air refueling Probe-and-drogue Unmanned aerial vehicles Docking Perception Collaborative control

Design and validation of a variable camber wing structure

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Chinese Journal of Aeronautics 2024年第2期37卷 1-11页

作者： Xiasheng SUN Jingfeng XUE Jin ZHOU Zhigang WANG Wenjuan WANG Mengjie ZHANG Chinese aeronautical Establishment Beijing 100012China School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Aircraft Strength Research Institute of China Xi’an 710065China Graduate School of Chinese aeronautical Establishment Yangzhou 225002China

Variable camber wing technology is one of the important development trends of green aviation at *** smooth,seamless,continuous and adaptive change of wing camber,the aerodynamic performance is improved in achieving increase in lift and reduction in resistance and *** on the aerodynamic validation model CAE-AVM,Chinese aeronautical Establishment(CAE)has carried out the design and validation of a variable camber wing,proposed an aerodynamic deformation matrix for the leading and trailing edges of aircraft wings in takeoff,landing and cruise *** structures and driving schemes are compared,and several key technology problems of leading and trailing edge deformation are solved.A full-size leading edge wind tunnel test piece with a span of 2.7 m and a trailing edge ground function test piece are *** deformation and shape maintenance capabilities of the leading edge is verified under real wind load conditions,and the load bearing and deformation capabilities of the trailing edge is verified under simulated follow-on *** results indicate that the leading and trailing edges of the variable camber wing can achieve the required deformation angle and have a certain load-bearing *** study can provide some insights into the application of variable camber wing technology for civil aircraft.

关键词： Variable camber wing Leading edge Trailing edge Structure Measurement and control Test

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Fruitful Transition

ChinAfrica 2024年第6期16卷 32-33页

作者： DR.CHRISTIAN SEKOMO BIRAME National Industrial Research and development agency Rwanda

Over the years,the African continent has been importing used gasoline and diesel vehicles including ones that are 10 years *** vehicles emit carbon dioxide,which is the leading cause of greenhouse gases(GHGs)that are driving the climate *** Rwanda,for example,road transport contributes to 13 percent of the country’s greenhouse emissions,according to the Rwanda Environment Management Authority(REMA).Africa as a developing continent continues to pollute air,partly due to the use of second-hand cars from developed countries.

关键词： Authority greenhouse dioxide

Bamboo-derived hard carbon/carbon nanotube composites as anode material for long-life sodium-ion batteries with high charge/discharge capacities

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Rare Metals 2024年第1期43卷 124-137页

作者： Sukanya Pothaya Chatwarin Poochai Nantikan Tammanoon Yaowamarn Chuminjak Tanaporn Kongthong Tanom Lomas Chakrit Sriprachuabwong Adisorn Tuantranont Graphene and Printed Electronics for Dual-Use Applications Research Division(GPERD) National Security and Dual-Use Technology Center(NSD)National Science and Technology Development Agency(NSTDA)Tambon Klong NuengAmphoe Klong LuangPathum Thani 12120Thailand

Hard carbon derived from bamboo for the anode material of sodium-ion batteries has a three-dimensional(3D) open framework structure and has naturally incorporated K-ions into its carbon structure,increasing the dinterlayer spacing of hard carbon materials for facilitating Na^(+) *** this work,bamboo-derived hard carbon was prepared via two carbonization temperatures at 700and 1000 ℃ for an hour and employed as an anode for sodium-ion batteries(SIB).X-ray diffraction(XRD) and Fourier transform(FT)-Raman spectroscopic results indicated the disordered structure with d-spacing(d_(002)) around0.36-0.37 nm,which is a benefit for sodium ion insertion/***,the composition between carbon-nanotube(CNT) and bamboo-derived hard carbon(BB) was synthesized by a ball mill with various contents of CNT(1 wt%,5 wt% and 10 wt%).At the optimal CNT content of 5 wt%,the sample exhibited excellent performance and outstanding *** the anode,the half-cell SIB using BB(700)w@5%CNT(with a carbonization temperature of700 ℃ and CNT loading of 5 wt%) delivered a high initial specific capacity of 268.9 mAh·g^(-1) at 0.1C and capacity retention of 78.6% after 500 cycles at *** full cell SIB fabrication BB(700)w@5%CNT in combination with Na_(3)V_(2)(PO4)_(3) as the cathode demonstrated a high specific capacity of 127.6 mAh·g^(-1) at 0.2C with its capacitive retention remaining of 78% at 1.0C after 1000 *** attained storage performance indicates that hard carbonCNT composite anode material enhanced the conductive path of electron transport and provided long-term cycling *** good electrochemical performance as well as the low cost and environment-friendliness of the bambooderived hard carbon proves its suitability for future sodium-ion batteries.

关键词： Hard carbon Bamboo Sodium-ion battery(SIB) Full cell

Chemical and mechanical properties of stainless, environment-friendly, and nonflammable Mg alloys (SEN alloys): A review

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Journal of Magnesium and Alloys 2024年第3期12卷 841-872页

作者： Jong Un Lee Hyun Ji Kim Sang-Cheol Jin Ye Jin Kim Young Min Kim Bong Sun You Jun Ho Bae Sung Hyuk Park Advanced Metals Division Korea Institute of Materials ScienceChangwon 51508Republic of Korea Department of Materials Science and Metallurgical Engineering Kyungpook National UniversityDaegu 41566Republic of Korea Missile Research Institute Agency for Defense DevelopmentDaejeon 34060Republic of Korea

This review article provides overall understanding of stainless,environment-friendly,and nonflammable Mg alloys(SEN alloys)recently developed at the Korea Institute of Materials *** alloys are produced by adding small amounts of Ca and Y(each<1 wt%)into commercial Mg–Al based alloys,resulting in exceptional ignition and corrosion resistances and impressive mechanical *** main advantages of SEN alloys are as follows.(1)A dense multi-oxide layer of SEN alloys comprising MgO,CaO,and Y_(2)O_(3) impedes the outward dispersion of Mg vapor and the inward penetration of O_(2) during oxidation,thereby enhancing the oxidation and ignition resistances.(2)The presence of Ca-and Y-based second-phase particles in SEN alloys can enhance their corrosion resistance because Ca-containing particles prevent the spread of corrosion,and the replacement of Al-containing particles with less noble ones containing Y(e.g.,Al–Mn–Y or Al–Y particles)retards corrosion.(3)The addition of minor amounts of Ca and Y renders excellent mechanical properties due to improved strengthening *** enhanced properties are attributed to more pronounced dynamic recrystallization and grain refining behaviors caused by the second-phase particles during extrusion.(4)Despite the presence of various types of second-phase particles,the fatigue properties of SEN9 alloys are similar to those of commercial AZ91 alloys.(5)Simultaneous introduction of Ca and Y suppresses the formation of Mg17Al12 discontinuous precipitates during aging,leading to the enhanced elongation of aged SEN alloys.(6)Adding mischmetal into the SEN9 alloy leads to a six-fold enhancement in ***,the studies conducted on SEN alloys demonstrate their excellent ignition and corrosion resistances and mechanical properties,which broaden the industrial applications of Mg alloys by addressing their inherent weaknesses.

关键词： SEN magnesium alloy Corrosion resistance Ignition resistance Mechanical properties Extrudability.

Stress-assisted corrosion mechanism of 3Ni steel by using gradient boosting decision tree machining learning method

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1311-1321页

作者： Xiaojia Yang Jinghuan Jia Qing Li Renzheng Zhu Jike Yang Zhiyong Liu Xuequn Cheng Xiaogang Li Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China AECC Key Laboratory of Advanced Corrosion and Protection of aeronautical Materials AECC Beijing Institute of Aeronautical MaterialsBeijing 100095China Shunde Innovation School University of Science and Technology BeijingFoshan 528399China

Traditional 3Ni weathering steel cannot completely meet the requirements for offshore engineering development,resulting in the design of novel 3Ni steel with the addition of microalloy elements such as Mn or Nb for strength enhancement becoming a *** stress-assisted corrosion behavior of a novel designed high-strength 3Ni steel was investigated in the current study using the corrosion big data *** information on the corrosion process was recorded using the galvanic corrosion current monitoring *** gradi-ent boosting decision tree(GBDT)machine learning method was used to mine the corrosion mechanism,and the importance of the struc-ture factor was *** exposure tests were conducted to verify the calculated results using the GBDT *** indic-ated that the GBDT method can be effectively used to study the influence of structural factors on the corrosion process of 3Ni ***-ferent mechanisms for the addition of Mn and Cu to the stress-assisted corrosion of 3Ni steel suggested that Mn and Cu have no obvious effect on the corrosion rate of non-stressed 3Ni steel during the early stage of *** the corrosion reached a stable state,the in-crease in Mn element content increased the corrosion rate of 3Ni steel,while Cu reduced this *** the presence of stress,the increase in Mn element content and Cu addition can inhibit the corrosion *** corrosion law of outdoor-exposed 3Ni steel is consistent with the law based on corrosion big data technology,verifying the reliability of the big data evaluation method and data prediction model selection.

关键词： weathering steel stress-assisted corrosion gradient boosting decision tree machining learning

Two-dimensional materials for tunable and nonlinear metaoptics

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Advanced Photonics 2024年第3期6卷 16-34页

作者： Zeng Wang Kandammathe Valiyaveedu Sreekanth Meng Zhao Jinpeng Nong Yincheng Liu Jinghua Teng agency for Science Technology and Research (A*STAR) Institute of Materials Research and Engineering (IMRE)

Metaoptics formed by ultrathin and planar building blocks enable compact and efficient optical devices that manipulate light at the nanoscale. The development of tunable metaoptics holds the promise of miniaturized and efficient optical systems that can dynamically adapt to changing conditions or requirements,propelling innovations in fields ranging from telecommunication and imaging to quantum computing and sensing. Two-dimensional(2D) materials show strong promise in enabling tunable metaoptics due to their exceptional electronic and optical properties from the quantum confinement within the atomically thin layers. In this review, we discuss the recent advancements and challenges of 2D material-based tunable metaoptics in both linear and nonlinear regimes and provide an outlook for prospects in this rapidly advancing area.

关键词： metaoptics tunable metaoptics two-dimensional optoelectronics nonlinear optics excitons polaritons

Harnessing endothelial cells and vascularization strategies for nerve regeneration

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Neural Regeneration Research 2024年第11期19卷 2337-2338页

作者： Papon Muangsanit Poppy Smith Virology and Cell Technology Research Team National Center for Genetic Engineering and Biotechnology(BIOTEC)National Science and Technology Development Agency(NSTDA)PathumthaniThailand UCL Centre for Nerve Engineering UCLLondonUK Department of Pharmacology UCL School of PharmacyUCLLondonUK

Peripheral nerves are essential components of the human body’s communication system,transmitting signals between the central nervous system and various body *** resulting from trauma or disease can result in debilitating sensory and motor *** injuries,particularly those resulting in significant gaps in the nerve tissue,pose a formidable challenge for clinicians and *** their limitations,including limited availability and donor site morbidity,nerve autografts remain the clinical gold standard for treating nerve injuries.

关键词： injuries nerves donor

Simulation on dynamic characteristics of TC4 cutting with crack defects

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Journal of Measurement Science and Instrumentation 2024年第3期15卷 387-396页

作者： SHI Lichen WANG Jian DOU Weitao YUAN Jiageng School of Mechanical and Electrical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China College of aeronautical Manufacturing Engineering Xi’an Aeronautical Polytechnic InstituteXi’an 710089China

Titanium alloys play an important role in aerospace and other ***,after precision forging and cold rolling process,some defects will appear on the subsurface of titanium alloy bars,thus reducing the surface quality and precision of turning *** study aimed at exploring the effect of crack defects on TC4 ***,the finite element cutting simulation model of TC4 material with crack defects was established in ***,the cutting parameters such as cutting force,stress concentration,chip morphology,residual stress were obtained by changing the variables such as the size and height of crack ***,the turning experiment was carried out on centerless *** results show that the cutting force changes abruptly when the defect position is located on the cutting path,the maximal stress occurs at the tip of the defect,and the mutation of stress value is more serious with the increase of defect size;the buckling deformation of chip morphology occurs and becomes less serious with the increase of the distance between the defect position and the workpiece surface;the surface residual stress near the defect is related to the stress when the tool is close to the defect,the larger defect size and the closer to the machined surface,the greater the residual ***,under certain processing conditions,the TC4 material should avoid large size defects or increase the distance between defects and the machined surface,so as to obtain better and stable surface quality.

关键词： crack defect TC4 ABAQUS centerless lathe