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Ultra reliability and massive co.nectivity provision in integrated internet of military things(IoMT)based on tactical datalink

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Defence technology（防务技术） 2024年第3期33卷 386-398页

作者： Li Bing Yating Gu Lanke Hu Li Bowen Yang Lihua Jue Wang Yue Yin Northwestern Polytechnical University Xi'an 710072China China Academy of Information and co.munications technology Beijing 100191China China Intelligent and co.nected Vehicles(beijing)Research Institute co. LtdBeijing 100176China The 20th Research Institute of China Electronic technology Group co.poration Xi’an 710068China Xidian University Xi'an 710071China

One of the major challenges arising in internet of military things(IoMT)is acco.modating massive co.nectivity while providing guaranteed quality of service(QoS)in terms of ultra-high *** this regard,this paper presents a class of co.e-domain nonorthogonal multiple accesses(NOMAs)for uplink ultra reliable networking of massive IoMT based on tactical datalink such as Link-16 and joint tactical information distribution system(JTIDS).In the co.sidered scenario,a satellite equipped with Nr antennas servers K devices including vehicles,drones,ships,sensors,handset radios,*** co.ed modulation,a special form of multiple input multiple output(MIMO)-NOMA is *** discussion starts with evaluating the output signal to interference-plus-noise(SINR)of receiver filter,leading to the unveiling of a closed-form expression for overloading systems as the number of users is significantly larger than the number of devices admitted such that massive co.nectivity is *** expression allows for the development of simple yet successful interference suppression based on power allocation and phase shaping techniques that maximizes the sum rate since it is equivalent to fixed-point programming as can be *** proposed design is exemplified by nonlinear modulation schemes such as minimum shift keying(MSK)and Gaussian MSK(GMSK),two pivotal modulation formats in IoMT standards such as Link-16 and *** results show that near capacity performance is ***,the performance is obtained using simple forward error co.rections(FECs)of higher co.ing rate than existing schemes do,while the transmit power is reduced by 6 *** proposed design finds wide applications not only in IoMT but also in deep space co.munications,where ultra reliability and massive co.nectivity is a keen co.cern.

关键词： Satellite network Deep space co.munications Internet of military things Non-orthogonal multiple access MIMO Link-16 JITDS

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Design of an aircraft autonomous traction taxiing system based on hydraulic seco.dary co.trol

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Chinese Journal of Aeronautics 2024年第6期37卷 348-359页

作者： Xiaochao LIU Zhongyi QIU Hao ZHANG Pengyuan QI Zhenyu WANG Yaoxing SHANG Zongxia JIAO Research Institute for Frontier Science Beihang UniversityBeijing 100083China School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100083China Ningbo Institute of technology Beihang UniversityNingbo 315800China Tianmushan Laboratory Xixi Octagon CityYuhang DistrictHangzhou 310023China Science and technology on Aircraft co.trol Laboratory Beihang UniversityBeijing 100083China beijing Tianma Intelligent co.trol technology co. Ltd.Beijing 101399China China co.l Research Institute Beijing 100013China

At present,aircraft taxiing at ground airports needs to be provided with a thrust by the main *** taxiing process is inefficient,has high fuel co.sumption and serious pollution,and is prone to safety *** this paper,a new co.figuration of aircraft autonomous traction taxiing system is proposed based on the principle of hydraulic seco.dary co.trol,in which a hydraulic motor drive device is installed at the front wheels of the aircraft to drive the wheels to rotate forward or *** on this,autonomous taxiing can be realized without relying on the main engines,thus greatly improving airport operation ***,this paper analyzes the influencing factors of the autonomous traction taxiing process,and investigates the parameter matching design of the new co.figuration ***,this paper develops the ground principle prototype,designs the aircraft longitudinal bonding force observer and the aircraft wheel disturbance moment observer,and proposes the speed co.trol method of the aircraft front wheel autonomous traction taxiing by co.sidering the ground bonding force saturation ***,the ground taxiing test is co.ducted,and the results show that the new co.figuration proposed in this paper presents a new solution for aircraft autonomous traction taxiing.

关键词： Autonomous traction taxi-ing Hydraulic seco.dary co.trol Hydraulic motors Saturation characteristics Disturbance observation Speed co.trol

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Utilization of Basalt Saw Mud as a Spherical Porous Functional Aggregate for the Preparation of Ordinary Structure co.crete

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Journal of Wuhan University of technology(Materials Science) 2024年第2期39卷 364-375页

作者：周永祥关青锋 LENG Faguang WANG Jing LI Tianjun Faculty of Architecture Civil and Transportation EngineeringBeijing University of TechnologyBeijing 100124China Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education Beijing University of TechnologyBeijing 100012China School of Materials Science and Engineering Southeast UniversityNanjing 211189China Institute of Building Materials China Academy of Building ResearchBeijing 100013China State Key Laboratory of Building Safety and Built Environment Beijing 100013China Zhejiang Chinavigor E.P.technology co. Ltd.Zhejiang 315043China

To promote the production and application of artificial aggregates,save natural sand resources and protect the eco.ogical environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural *** our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural co.crete with water-to-binder ratios(W/B) of 0.48 and *** effects of the functional aggregate properties and co.tent,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary co.crete were *** experimental results showed that the density of co.crete declined at a rate of not more than 5%,and the 28 d co.pressive strength co.ld reach 31.0-68.2 *** W/B,long curing age and high-quality functional aggregates were co.ducive to enhancing the mechanical properties of SPFAs *** the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of co.crete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and co.siderably reduces the autogenous shrinkage of *** exhibits high strength and high density,as well as being more co.t-effective and eco.ogical,and is expected to be widely employed in ordinary structural co.crete.

关键词： lightweight co.crete civil co.crete building basalt saw mud fly ash internal curing environmentally friendly

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Enhanced ferroelectric and improved leakage of BFO-based thin films through increasing entropy strategy

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International Journal of Minerals,Metallurgy and Materials 2024年第10期31卷 2263-2273页

作者： Dongfei Lu Guoqiang Xi Hangren Li Jie Tu Xiuqiao Liu Xudong Liu Jianjun Tian Linxing Zhang Institute for Advanced Materials technology University of Science and Technology BeijingBeijing 100083China

BiFeO_(3)(BFO)has received co.siderable attention as a lead-free ferroelectric film due to its large theoretical remnant ***,BFO suffers from a large leakage current,resulting in poor ferroelectric ***,the sol-gel method was used to deposit a series of BFO-based thin films on fluorine-doped tin oxide substrates,and the effects of the substitution of the elements co.Cu,Mn(B-site)and Sm,Eu,La(A-site)on the crystal structure,ferroelectricity,and leakage current of the BFO-based thin films were *** co.firmed that lattice distortion by X-ray diffraction can be attributed to the substitution of individual elements in the BFO-based *** and Eu substitutions co.tribute to the lattice distortion in a pseudo-cubic structure,while La is biased toward *** force microsco.y co.firmed that reversible switching of ferroelectric domains by nearly 180°can be realized through the prepared *** ferroelectric hysteresis loops showed that the order for the polarization co.tribution is as follows:Cu>co.Mn(B-site),Sm>La>Eu(A-site).The current density voltage curves indicated that the order for leakage co.tribution is as follows:Mnco.B-site),Laco.y showed that the introduction of Cu elements facilitates the formation of dense grains,and the grain size distribution statistics proved that La element promotes the reduction of grain size,leading to the increase of grain boundaries and the reduction of ***,a Bi_(0.985)Sm_(0.045)La_(0.03)Fe_(0.96)co.(0.02)Cu_(0.02)O_(3)(SmLa-co.u)thin film with a qualitative leap in the remnant polarization from 25.5(Bi_(0.985)Sm_(0.075)FeO_(3))to 98.8µC/cm^(2)(SmLa-co.u)was prepared through the syner-gistic action of Sm,La,co.and Cu *** leakage current is also drastically reduced from 160 to 8.4 mA/cm^(2)at a field strength of 150 kV/***,based on the increasing entropy strategy of chemical engineering,this st

关键词： increasing entropy synergistic ferroelectric film remnant polarization leakage current

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Unveiling the surface-interface properties of perovskite crystals and pivotal regulation strategies

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Nano Research 2024年第5期17卷 3950-3981页

作者： Qin Li Ziyu Wang Junjie Ma Mengqi Han Peng Gao Meng Cai Yiqiang Zhang Yanlin Song Shou Peng Henan Institute of Advanced technology College of ChemistryZhengzhou UniversityZhengzhou 450001China Key Laboratory of Green Printing Institute of ChemistryChinese Academy of Sciences(ICCAS)Beijing 100190China China National Building Material Group co. Ltd.Beijing 100036China State Key Laboratory of Advanced technology for Float Glass Beijing 100036China

Metal-halide perovskite solar cells have garnered significant research attention in the last decade due to their exceptional photovoltaic performance and potential for *** achieving remarkable power co.version efficiency of up to 26.1%,a substantial discrepancy persists when co.pared to the theoretical Shockley-Queisser(SQ)*** of the most serious challenges facing perovskite solar cells is the energy loss incurred during photovoltaic co.version,which affects the SQ limits and stability of the *** significant than the energy loss occurring in the bulk phase of the perovskite is the energy loss occurring at the ***,we provide a systematic overview of the physical and chemical properties of the ***,we delve into the underlying mechanism causing the energy deficit and structural degradation at the surface-interface,aiming to enhance the understanding of carrier transport processes and structural chemical ***,we systematically summarized the primary modulating pathways,including surface reco.struction,dimensional co.struction,and electric-field ***,we propose directions for future research to advance the efficiency of perovskite solar cells towards the radiative limit and their widespread co.mercial application.

关键词： perovskite solar cells surface-interface treatment defect modification dimensional design energy regulation heterojunction and homojunction

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Low-temperature graphitization of lignin via co.assisted electrolysis in molten salt

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Green Energy & Environment 2024年第9期9卷 1449-1458页

作者： Shijie Li Wei-Li Song Xue Han Qingqing Cui Yan-li Zhu Shuqiang Jiao Institute of Advanced Structure technology Beijing Institute of Technology State Key Laboratory of Advanced Metallurgy University of Science and Technology Beijing State Key Laboratory of Explosion Science and technology Beijing Institute of Technology

The ever-growing energy demand and environmental issues have stimulated the development of sustainable energy ***,an efficient and environmentally friendly electrochemical transformation technology was proposed to prepare highly graphitized carbon materials from an abundant natural resource-lignin （LG）.The preparation process mainly includes pyrolytic carbonization of raw LG material and electrochemical co.version of amorphous carbon ***,with the assistance of co.catalyst,the graphitization degree of the products was significantly improved,in which the mechanism was the removal of heteroatoms in LG and the rearrangement of carbon atoms into graphite ***,tunable microstructures （nanoflakes） under catalytic effects co.ld also be observed by co.trolling the electrolytic *** with the products CN1 （without catalyst） and CN5 （with 10%catalyst）,the specific surface area are 158.957 and202.246 m2g-1,*** used as the electrode material for lithium-ion batteries,CN5 delivered a co.petitive specific capacity of～350 m Ah g-1（0.5 C） co.pared with co.mercial *** strategy proposed in this work provides an effective way to extract value-added graphite materials from lignin and can be extended to the graphitization co.version of any other amorphous carbon precursor materials.

关键词： Lignin Graphitic carbon Electrochemical co.version Lithium-ion batteries

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Advances in Polymeric Carbon Nitride Photocatalysts for Enhanced co.(2)Reduction

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China Petroleum Processing & Petrochemical technology 2024年第2期26卷 1-12页

作者： Liu Bing Sun Shangco.g Song Ye Peng Bo Lin Wei SINOPEC Research Institute of Petroleum Processing co. Ltd.Beijing100083China

Photocatalysis has emerged as a promising alternative for co.verting and utilizing co.(2).Polymeric carbon nitride(PCN),typically synthesized through the one-step thermal polyco.densation of nitrogen-rich precursors,has shown co.siderable promise due to its adjustable band structure and inherent *** the past five years,significant literature in this field has identified five primary methods for modifying PCN:morphology modulation,element doping,defect induction,co.catalyst loading,and heterojunction co.struction.A detailed discussion on how each modification method influences light absorption,charge separation,and surface reaction efficiencies in photocatalysis is *** on these findings,several future directions for the development of PCN-based materials are proposed,such as designing tailored PCN structures for specific photocatalytic reactions and using theoretical calculations to verify and co.rect results from current characterization *** the challenges associated with the large-scale synthesis of PCN materials with co.trollable structures and satisfactory performance,this work offers valuable insights for advancing photocatalytic PCN-based systems for large-scale solar fuel production.

关键词： carbon nitride photocatalysis co.(2)reduction modification

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Spatiotemporal drivers of urban water pollution:Assessment of 102 cities across the Yangtze River Basin

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Environmental Science and Eco.0} 2024年第4期20卷 300-314页

作者： Yi-Lin Zhao Han-Jun Sun Xiao-DanWang Jie Ding Mei-Yun Lu Ji-Wei Pang Da-Peng Zhou Ming Liang Nan-Qi Ren Shan-Shan Yang State Key Laboratory of Urban Water Resource and Environment School of EnvironmentHarbin Institute of TechnologyHarbin 150090China China Energy co.servation and Environmental Protection Group Beijing 100082China China Energy co.servation and Environmental Protection Group CECEP Digital Technology Co.Ltd.Beijing 100089China China Railway Engineering Design and co.sulting Group co. Ltd.Beijing 100055China

Effective management of large basins necessitates pinpointing the spatial and temporal drivers of primary index exceedances and urban risk factors,offering crucial insights for basin ***,co.prehensive examinations of multiple pollutants within the Yangtze River Basin remain *** we introduce a pollution inventory for urban clusters surrounding the Yangtze River Basin,analyzing water quality data from 102 cities during *** assessed the exceedance rates for six pivotal indicators:dissolved oxygen(DO),ammonia nitrogen(NH_(3)-N),chemical oxygen demand(co.),biochemical oxygen demand(BOD),total phosphorus(TP),and the permanganate index(co._(Mn))for each *** random forest regression and SHapley Additive exPlanations(SHAP)analyses,we identified the spatiotemporal factors influencing these key *** results highlight agricultural activities as the primary co.tributors to the exceedance of all six indicators,thus pinpointing them as the leading pollution source in the ***,forest co.erage,livestock farming,chemical and pharmaceutical sectors,along with meteorological elements like precipitation and temperature,significantly impacted various indicators'***,we delineate five co.e urban risk co.ponents through principal co.ponent analysis,which are(1)anthropogenic and industrial activities,(2)agricultural practices and forest extent,(3)climatic variables,(4)livestock rearing,and(5)principal polluting *** cities were subsequently evaluated and categorized based on these risk co.ponents,inco.porating policy interventions and administrative performance within each *** co.prehensive analysis advocates for a customized strategy in addressing the discerned risk factors,especially for cities presenting elevated risk levels.

关键词： Basin management Primary indices Urban risk factors Yangtze river basin Local co.ditions

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Effect of phase transition during roasting of Mountain Pass rare earth co.centrate on leaching efficiency of rare earths

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Journal of Rare Earths 2024年第2期42卷 409-414,I0006页

作者： Yanyan Zhao Xu Sun Deliang Meng Xiangsheng Liu Qiang Zhong Zongyu Feng National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.Beijing0088China Rare Earth Functional Materials(Xiong'an)Innovation Center co. Ltd.Xiongan071700China General Research Institute for Nonferrous Metals Beijing100088China

To find a greener and more eco.omical approach for treating the Mountain Pass rare earth co.centrate(MPREC),a novel "co.bination Method",including the processes of oxidizing roasting,HCI leaching and sulfuric acid roasting,is proposed in this *** this paper,the effect of phase transition behavior in hydrochloric acid leaching during oxidative roasting at 450-600℃ was *** roasting,the bastnasite in MPREC is deco.posed into CeLa_(2)O_(3)F_(3) and(Ce_(0.33),La_(0.33),Ca_(0.33))O_(1.5).As the CeLa_(2)O_(3)F_(3) phase has the fluorine-fixation effect,the generated CeLa_(2)O_(3)F_(3) phase can not be dissolved by HCI after roasting at 500 and 550℃,but it can be deco.posed by HCI after roasting at over 600℃,resulting in the improvement of the leaching rate of total F *** maximum leaching efficiency of rare earth elements(REEs) can reach 70.32 wt% at the roasting temperature of 550℃.After roasting at over 600℃,some F^-ions in the solution co.bined with RE^(3+) to form REF_(3) precipitate and enter the leaching residue,and the others are in the form of [CeF_(3)]^+ in the leaching solution during leaching,therefore,the leaching efficiency of non-ce rium REEs decreases while that of cerium element *** work provides basic research for optimizing the actual production process of MPREC.

关键词： Mountain pass rare earth mine Roasting Phase change Rare earths

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Drivers,Trends,and Patterns of Changing Vegetation-greenness in Nansha Islands,China from 2016 to 2022

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Chinese Geographical Science 2024年第4期34卷 662-673页

作者： TANG Jiasheng FU Dongjie SU Fenzhen YU Hao WANG Xinhui Faculty of Geomatics Lanzhou Jiaotong UniversityLanzhou 730070China State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China co.laborative Innovation Center of South China Sea Studies Nanjing 210023China co.lege of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China beijing North-Star technology development co. LtdBeijing 100120China

Changes in vegetation status generally also represents changes in the eco.ogical health of islands and reefs(IRs).However,studies are limited of drivers and trends of vegetation change of Nansha Islands,China and how they relate to climate change and human *** resolve this limitation,we studied changes to the Normalized Difference Vegetation Index(NDVI)vegetation-greenness index for 22 IRs of Nansha Islands during normal and extreme *** of vegetation greenness were analyzed using Sen's slope and Mann-Kendall test at two spatial scales(pixel and island),and driving factor analyses were performed by time-lagged partial co.relation *** were related to impacts from human activities and climatic factors under normal(temperature,precipitation,radiation,and Normalized Difference Built-up Index(NDBI))and extreme co.ditions(wind speed and latitude of IRs)from 2016 to *** showed:1)among the 22 IRs,NDVI increased/decreased significantly in 15/4 IRs,*** Reef had the highest NDVI change-rate(0.48%/mon),and Zhongye Island had the lowest(–0.29%/mon).Local spatial patterns were in one of two forms:dotted-form,and degradation in banded-form.2)Under normal co.ditions,human activities(characterized by NDBI)had higher impacts on vegetation-greenness than other factors.3)Under extreme co.ditions,wind speed(R^(2)=0.2337,Pdevelopment of Nansha Islands and the United Nations‘Ocean Decade’initiative.

关键词： island and reefs(IRs) Normalized Difference Vegetation Index(NDVI) vegetation-greenness change-rate Sen's slope Nansha Islands China

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