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Elliptical encirclement control capable of reinforcing performances for UAVs around a dynamic target

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Defence Technology（防务技术） 2024年第2期32卷 104-119页

作者： fei zhang Xingling Shao Yi Xia Wendong zhang National Key Laboratory for Electronic Measurement Technology School of Instrument and ElectronicsNorth University of ChinaTaiyuan030051China

Most researches associated with target encircling control are focused on moving along a circular orbit under an ideal environment free from external ***,elliptical encirclement with a time-varying observation radius,may permit a more flexible and high-efficacy enclosing solution,whilst the non-orthogonal property between axial and tangential speed components,non-ignorable environmental perturbations,and strict assignment requirements empower elliptical encircling control to be more challenging,and the relevant investigations are still *** this line,an appointed-time elliptical encircling control rule capable of reinforcing circumnavigation performances is developed to enable Unmanned Aerial Vehicles(UAVs)to move along a specified elliptical path within a predetermined reaching *** remarkable merits of the designed strategy are that the relative distance controlling error can be guaranteed to evolve within specified regions with a designer-specified convergence ***,wind perturbations can be online counteracted based on an unknown system dynamics estimator(USDE)with only one regulating parameter and high computational *** tool demonstrates that all involved error variables are ultimately limited,and simulations are implemented to confirm the usability of the suggested control algorithm.

关键词： Elliptical encirclement Reinforced performances Wind perturbations UAVs

Insights into the provenance implication of leaf wax n-alkanes along the lower Yellow River

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Science China Earth Sciences 2024年第6期67卷 2001-2018页

作者： Liang zhang Jinzhao LIU Chong JIANG fei zhang Zhisheng AN School of Human Settlements and Civil Engineering Xi’an Jiaotong UniversityXi’an 710054China State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an 710061China National Observation and Research Station of Earth Critical Zone on the Loess Plateau of Shaanxi Xi’an 710061China

Serving as one of the largest rivers in terms of both sediment and organic carbon transport fluxes in the world,the Yellow River plays a crucial role in regional biogeochemical process as well as in the global carbon ***,although a large number of studies have been carried out on the flux,composition,source and seasonal variation of total particulate organic carbon in the Yellow River so far,studies on molecular biomarkers at different spatial and temporal scales are still *** this study,we focus on the molecular and hydrogen isotopic properties of leaf wax n-alkanes among different types of samples which obtained from different seasons(flood ***-flood)along the lower Yellow *** molecular distribution of n-alkanes show that the riparian topsoils are subject to inputs from the overlying vegetation,while the suspended sediments from the flood season are characterized by the mixing of soil materials which originate from various stratigraphy with different ages on the Chinese Loess *** to the contrasting hydrodynamic conditions,the n-alkanes in suspended sediments also show distinct molecular composition between flood and non-flood ***,considering the effect of climatic factors,the proportion of monocots in flood-season suspended sediments is calculated from a semi-quantitative perspective using δ^(2)H_(wax).Our findings may bring to light new considerations for the interpretation of leaf wax proxies in studies of organic matter sources of Yellow River.

关键词： Molecular distribution Hydrogen isotopic composition Leaf wax n-alkanes Suspended sediments Lower Yellow River

An efficient parallel algorithm of variational nodal method for heterogeneous neutron transport problems

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Nuclear Science and Techniques 2024年第4期35卷 29-45页

作者： Han Yin Xiao-Jing Liu Teng-fei zhang School of Nuclear Science and Engineering Shanghai Jiao Tong UniversityShanghai 2002040China

The heterogeneous variational nodal method(HVNM)has emerged as a potential approach for solving high-fidelity neutron transport ***,achieving accurate results with HVNM in large-scale problems using high-fidelity models has been challenging due to the prohibitive computational *** paper presents an efficient parallel algorithm tailored for HVNM based on the Message Passing Interface *** algorithm evenly distributes the response matrix sets among processors during the matrix formation process,thus enabling independent construction without *** the formation tasks are completed,a collective operation merges and shares the matrix sets among the *** the solution process,the problem domain is decomposed into subdomains assigned to specific processors,and the red-black Gauss-Seidel iteration is employed within each subdomain to solve the response matrix ***-to-point communication is conducted between adjacent subdomains to exchange data along the *** accuracy and efficiency of the parallel algorithm are verified using the KAIST and JRR-3 test *** results obtained with multiple processors agree well with those obtained from Monte Carlo *** parallelization of HVNM results in eigenvalue errors of 31 pcm/-90 pcm and fission rate RMS errors of 1.22%/0.66%,respectively,for the 3D KAIST problem and the 3D JRR-3 *** addition,the parallel algorithm significantly reduces computation time,with an efficiency of 68.51% using 36 processors in the KAIST problem and 77.14% using 144 processors in the JRR-3 problem.

关键词： Neutron transport Variational nodal method Parallelization KAIST JRR-3

Reduction of unactivated alkyl chlorides enabled by light-induced single electron transfer

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Science China Chemistry 2024年第2期67卷 471-481页

作者： Lei Dai Zhao-fei zhang Xiang-Yu Chen School of Chemical Sciences University of the Chinese Academy of SciencesBeijing100049China Institute of Chemistry Chinese Academy of SciencesBeijing100190China Binzhou Institute of Technology Weiqiao-UCAS Science and Technology ParkBinzhou256606China

Alkyl chlorides are abundant and easily accessible starting ***,due to the high reduction potentials associated with unactivated alkyl chlorides,achieving their single electron reduction remains a persistent *** challenge has spurred the exploration of efficient activation methods to overcome this *** recent years,photocatalysis has emerged as a mild and potent tool for the single electron reduction of unactivated alkyl chlorides,opening up new possibilities in this *** the rapid advancements in this area,a comprehensive review that provides a conceptual understanding of this emerging field,with a specific focus on reaction design and catalytic mechanisms,would be timely and highly ***,we present an overview of various synthetic techniques for photoinduced single electron reduction of unactivated alkyl ***,we also discuss the limitations of the present methods and future directions that lie ahead in this field.

关键词： photocatalysis unactivated alkyl chlorides single electron transfer radical reactions

Degradable magnesium alloy suture promotes fibrocartilaginous interface regeneration in a rat rotator cuff transosseous repair model

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Journal of Magnesium and Alloys 2024年第1期12卷 384-393页

作者： Baoxiang zhang Wen zhang fei zhang Chao Ning Mingyang An Ke Yang Lili Tan Qiang zhang Department of Sports Medicine Chinese PLA General HospitalBeijing 100853China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Medical School of PLA Beijing 100853China Institute of Orthopedics Chinese PLA General HospitalBeijing Key Lab of Regenerative Medicine in OrthopedicsKey Lab of Musculoskeletal Trauma&War Injuries of Chinese PLABeijing 100853China

Despite transosseous rotator cuff tear repair using sutures is widely accepted for tendon-bone fixation,the fibrocartilaginous enthesis regeneration is still hardly achieved with the traditional *** the present work,degradable magnesium(Mg)alloy wire was applied to suture supraspinatus tendon in a rat acute rotator cuff tear model with Vicryl Plus 4±0 absorbable suture as *** shoulder joint humerus-supraspinatus tendon complex specimens were retrieved at 4,8,and 12 weeks after *** Mg alloy suture groups showed better biomechanical properties in terms of ultimate load to *** observation showed that hyperplastic response of the scar tissue at the tendon-bone interface is progressively alleviated over time in the both Mg alloy suture and Vicryl suture *** the histological analysis,for Mg alloy suture groups,chondrocytes appear to proliferate at 4 weeks postoperatively,and the tendon-bone interface showed an orderly structural transition zone at 8 weeks *** collagenous fiber tended to be aligned and the tendon-bone interlocking structures apparently formed,where transitional structure from unmineralized fibrocartilage to mineralized fibrocartilage was closer to the native fibrocartilaginous *** vivo degradation of the magnesium alloy wire was completed within 12 *** results indicated that Mg alloy wire was promising as degradable suture with the potential to promotes fibrocartilaginous interface regeneration in rotator cuff repair.

关键词： Rotator cuff repair Mg alloy wire Tendon-bone healing Fibrocartilaginous interface

Could the EU carbon border adjustment mechanism promote climate mitigation?An economy-wide analysis

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Advances in Climate Change Research 2024年第3期15卷 557-571页

作者： Kun zhang Yun-fei YAO Xiang-Yan QIAN Yu-fei zhang Qiao-Mei LIANG Yi-Ming WEI College of Economics and Management Beijing University of TechnologyBeijing 100124China Center for Energy and Environmental Policy Research Beijing Institute of TechnologyBeijing 100081China School of Management and Economics Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Energy Economics and Environmental Management Beijing 100081China Sinopec Research Institute of Petroleum Engineering SinopecBeijing 100101China College of Economics and Management Nanjing Agricultural UniversityNanjing 210095China

Due to concerns about carbon leakage and sectoral competitiveness,the European Union(EU)proposed implementing the carbon border adjustment mechanism(CBAM).The effectiveness and potential negative consequences of CBAM have aroused extensive *** the perspective of the economy-wide analysis,this study uses a global computable general equilibrium model to explore the rationality of CBAM from the aspects of socioeconomic impact and the effects of promoting climate ***,the potential alternative mechanism of CBAM is *** results show that CBAM can reduce the EU's gross domestic product(GDP)loss;however,the GDP loss in all other regions ***,CBAM raises household welfare losses in most regions,including the ***,although CBAM can reduce the marginal abatement cost in eight regions,it comes at the cost of greater economic ***,the economic and household welfare cost of raising emissions reduction targets in regions like the USA and Japan is substantially higher than the impact of passively accepting the CBAM;therefore,CBAM's ability to drive ambitious emission reduction initiatives may be ***,for the potential alternative mechanism,from the perspective of reducing economic cost and household welfare losses,the EU could implement domestic tax cuts in the short-term and promote global unified carbon pricing in the long-term.

关键词： Border adjustment mechanism Computable general equilibrium model Carbon price Climate policy Global carbon pricing

Taiji-TianQin-LISA network:Precisely measuring the Hubble constant using both bright and dark sirens

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 59-77页

作者： Shang-Jie Jin Ye-Zhu zhang Ji-Yu Song Jing-fei zhang Xin zhang Key Laboratory of Cosmology and Astrophysics(Liaoning)&College of Sciences Northeastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

In the coming decades,the space-based gravitational-wave(GW)detectors such as Taiji,TianQin,and LISA are expected to form a network capable of detecting millihertz GWs emitted by the mergers of massive black hole binaries(MBHBs).In this work,we investigate the potential of GW standard sirens from the Taiji-TianQin-LISA network in constraining cosmological *** the optimistic scenario in which electromagnetic(EM)counterparts can be detected,we predict the number of detectable bright sirens based on three different MBHB population models,i.e.,popⅢ,Q3d,and *** results show that the TaijiTianQin-LISA network alone could achieve a constraint precision of 0.9%for the Hubble constant,meeting the standard of precision ***,the Taiji-TianQin-LISA network could effectively break the cosmological parameter degeneracies generated by the CMB data,particularly in the dynamical dark energy *** combined with the CMB data,the joint CMB+Taiji-TianQin-LISA data offerσ(w)=0.036 in the wCDM model,which is close to the latest constraint result obtained from the CMB+SN *** also consider a conservative scenario in which EM counterparts are not *** to the precise sky localizations of MBHBs by the Taiji-TianQin-LISA network,the constraint precision of the Hubble constant is expected to reach 1.2%.In conclusion,the GW standard sirens from the Taiji-TianQin-LISA network will play a critical role in helping solve the Hubble tension and shedding light on the nature of dark energy.

关键词： space-based gravitational wave detection standard sirens the Taiji-TianQin-LISA network the Hubble constant dark energy

Seismic-induced surficial failure of cohesive slopes using three-dimensional limit analysis:A case study of the Wangjiayan landslide in Beichuan, China

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 537-545页

作者： Gao Yufeng Liu Yang Geng Weijuan zhang fei Key Laboratory of the Ministry of Education for Geomechanics and Embankment Engineering College of Civil and Transportation EngineeringHohai UniversityNanjing 210098China Department of Civil Engineering Faculty of Civil Engineering and MechanicsJiangsu UniversityZhenjiang 212013China

A seismic-induced landslide is a common geological catastrophe that occurs in *** Wangjiayan landslide,which was triggered by the Wenchuan earthquake,is a typical case in *** Wanjiayan landslide caused many casualties and resulted in enormous property *** study constructs a simple surficial failure model based on the upper bound approach of three-dimensional(3D)limit analysis to evaluate the slope stability of the Wangjiayan case,while a traditional two-dimensional(2D)analysis is also conducted as a reference for comparison with the results of the 3D analysis.A quasi-static calculation is used to study the effect of the earthquake in terms of horizontal ground acceleration,while a parametric study is conducted to evaluate the critical cohesion of *** than employing a 3D analysis,using the 2D analysis yields an underestimation regarding the safety *** the Wangjiayan landslide,the difference in the factors of safety between the 3D and 2D analyses can reach 20%.The sliding surface morphology as determined by the 3D method is similar to actual morphology,and the parameters of both are also compared to analyze the reliability of the proposed 3D method.

关键词： landslide Wenchuan earthquake surficial failure limit analysis stability quasi-static

Prospects for weighing neutrinos in interacting dark energy models using joint observations of gravitational waves andγ-ray bursts

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Chinese Physics C 2024年第9期48卷 225-233页

作者： Lu Feng Tao Han Jing-fei zhang Xin zhang College of Physical Science and Technology Shenyang Normal UniversityShenyang 110034China Key Laboratory of Cosmology and Astrophysics(Liaoning Province)&Department of Physics College of SciencesNortheastern UniversityShenyang 110819China Key Laboratory of Data Analytics and Optimization for Smart Industry(Ministry of Education) Northeastern UniversityShenyang 110819China National Frontiers Science Center for Industrial Intelligence and Systems Optimization Northeastern UniversityShenyang 110819China

Cosmological observations can be used to weigh neutrinos,but this method is model-dependent,with results relying on the cosmological model *** we consider interactions between dark energy and dark matter,the neutrino mass constraints differ from those derived under the standard *** the contrary,gravitational wave(GW)standard siren observations can measure absolute cosmological distances,helping to break parameter degeneracies inherent in traditional cosmological observations,thereby improving constraints on neutrino *** paper examines the constraints on neutrino mass within interacting dark energy(IDE)models and explores how future GW standard siren observations could enhance these *** multi-messenger GW observations,we consider the joint observations of binary neutron star mergers by third-generation ground-based GW detectors and shortγ-ray burst observations by missions similar to the THESEUS satellite *** current cosmological observations(CMB+BAO+SN),we obtain an upper limit on the neutrino mass in the IDE models of 0.15(or 0.16)*** the inclusion of GW data,the upper limit on the neutrino mass improves to 0.14 *** indicates that in the context of IDE models,the improvement in neutrino mass constraints from GW observations is relatively ***,GW observations significantly enhance the constraints on other cosmological parameters,such as matter density parameter,the Hubble constant,and coupling strength between dark energy and dark matter.

关键词： interacting dark energy neutrino mass gravitational wave standard siren cosmology