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Greedy Lattice Paths with General Weights

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Acta Mathematica Sinica,English Series 2024年第9期40卷 2213-2222页

作者： Yin Shan CHANG An qi ZheNG College of Mathematics Sichuan UniversityChengdu 610065P.R.China

Let{X_(v):v∈Z^(d)}be *** *** S(π)=Σ_(v∈π)X_(v)be the weight of a self-avoiding lattice pathπ.Let M_(n)=max{S(π):πhas length n and starts from the origin}.We are interested in the asymptotics of Mn as n→∞.This model is closely related to the first passage percolation when the weights{X_(v):v∈Z^(d)}are non-positive and it is closely related to the last passage percolation when the weights{X_(v):v∈Z^(d)}are *** general weights,this model could be viewed as an interpolation between first passage models and last passage ***,this model is also closely related to a variant of the position of right-most particles of branching random *** the two assumptions that∃α>0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)here exists a finite real number M such that Mn/n converges to a deterministic constant M in L^(1)as n tends to *** under the stronger assumptions that∃α>0,E(X_(0)^(+))^(d)(log^(+)X_(0)^(+))^(d+α)he same constant M almost surely as n tends to infinity.

关键词： Last passage percolation first passage percolation greedy lattice path

Enhancing undulation of soft robots in granular media:A numerical and experimental study on the effect of anisotropic scales

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Biomimetic Intelligence & Robotics 2024年第2期4卷 63-70页

作者： Longchuan Li Chaoyue Zhao Shuqian he qiukai qi Shuai Kang Shugen Ma College of Information Science and Technology Bejing University of Chemical TechnologyBejing 100029China School of Engineering Mathematics and Technology University of BristolBristol BS81THUK College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China Thrust of Robotics and Autonomous Systems The Hong Kong University of Science and Technology(Guangzhou)Guangzhou 511453China

Generating efficient locomotion in granular media is important,although it is difficult for *** by the fact that sand vipers usually have saw-like scales,in this study,we design a soft undulation robot with tangential anisotropic friction to enhance the undulation performance of soft robots in granular media.A mathematical model was derived and numerical simulations were conducted accordingly to investigate the effectiveness of tangential friction anisotropy for undulation gait generation in granular *** particular,we introduce a pseudo-rigid-body dynamics model consisting of links and joints while simulating the pneumatic actuation method to more closely approximate the response of soft ***,a soft snake-like robot was fabricated,and its forward and reverse undulations were compared in two sets of controlled *** consistency between the experimental results and the numerical simulations confirms that tangential anisotropic friction induces a propulsive effect in undulation,thereby increasing the robot's locomotion *** discovery provides new insights into the design of undulation robots in granular environments.2024 The Author(s).Published by Elsevier *** behalf of Shandong *** is an open access articleunder the CCBY license(http://***/licenses/by/4.0/).

关键词： Granular media Anisotropicity Pseudo-rigid-body model Soft robot Undulation

Tendencies of alloyed engineering in BiOX-based photocatalysts:a state-of-the-art review

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Rare Metals 2024年第4期43卷 1488-1512页

作者： Yan-Dong Sun Chao Zeng Xue Zhang Zi-qi Zhang Bo Yang Sheng-qi Guo Tianjin Key Laboratory of Clean Energy and Pollutant Control School of Energy and Environmental EngineeringHebei University of TechnologyTianjin300401China State-Province Joint Engineering Laboratory of Zeolite Membrane Materials Institute of Advanced MaterialsCollege of Chemistry and Chemical EngineeringJiangxi Normal UniversityNanchang330022China Anhui Province Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation School of Physics and Electronic InformationAnhui Province Industrial Generic Technology Research Center for Alumics MaterialsHuaibei Normal UniversityHuaibei235000China

Energy-saving and environmentally friendly photocatalysis has emerged as a popular research area in response to issues with energy scarcity and environmental *** to the unique layer-like structure,BiOX(Cl,Br,I)is frequently used in ***,inherent flaws in BiOX,such as an inappropriate band gap and low carrier separation efficiency,restrict its capacity for *** to the tunable grouping layer,alloying engineering is employed to optimize the intrinsic properties of BiOX and alloyed BiOX becomes a promising photocatalytic *** review describes the structure of BiOX,where tunable halogen layers provide favorable conditions for the implementation of alloying engineering to improve intrinsic *** article compares the effects and mechanisms of alloying engineering on the optimization of the energy band structure and carrier behavior of BiOX,and lists various modification methods used to improve the optimization of the intrinsic properties by alloying engineering,including defect engineering,morphology control as well as the synergy between alloying and other modification methods(bismuth-rich strategies,cation doping,construction of heterojunctions and plasma resonance effects).Subsequently,applications of alloyed BiOX in energy and environmental fields are summarized,including contaminant degradation,antibacterial,CO_(2)reduction,nitrogen fixation and organic ***,we summarize the current challenges and future directions of alloyed *** is expected that this work will provide guidance and assistance for an in-depth study and understanding of the mechanisms of alloying engineering to optimize intrinsic properties and design alloyed BiOX with higher photocatalytic activity.

关键词： Bismuth oxyhalide Photocatalytic Alloyed engineering Microstructural regulation Application

Moments of inertia of triaxial nuclei in covariant density functional theory

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NUCLEAR SCIENCE AND TECHNIQUES 2024年第10期35卷 1-11页

作者： Wang, Yu-Meng Chen, qi-Bo East China Normal Univ Dept Phys Shanghai 200241 Peoples R China

The covariant density functional theory (CDFT) and five-dimensional collective Hamiltonian (5DCH) are used to analyze the experimental deformation parameters and moments of inertia (MoIs) of 12 triaxial nuclei as extracted by Allmond and Wood [J. M. Allmond and J. L. Wood, Phys. Lett. B 767, 226 (2017)]. We find that the CDFT MoIs are generally smaller than the experimental values but exhibit qualitative consistency with the irrotational flow and experimental data for the relative MoIs, indicating that the intermediate axis exhibites the largest MoI. Additionally, it is found that the pairing interaction collapse could result in nuclei behaving as a rigid-body flow, as exhibited in the 186-192 Os case. Furthermore, by incorporating enhanced CDFT MoIs (factor of f approximate to 1.55\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$f\approx 1.55$$\end{document}) into the 5DCH, the experimental low-lying energy spectra and deformation parameters are reproduced successfully. Compared with both CDFT and the triaxial rotor model, the 5DCH demonstrates superior agreement with the experimental deformation parameters and low-lying energy spectra, respectively, emphasizing the importance of considering shape fluctuations.

关键词： Moment of inertia Trixial nucleus Covariant density functional theory Five-dimensional collective Hamiltonian Low-lying energy spectrum HARTREE-BOGOLIUBOV TheORY

Comparative studies on Fenton-like reactions catalyzed by Fe_(3)O_(4) loaded inside and outside halloysite nanotubes for the removal of organic pollutants

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Frontiers of Materials Science 2024年第1期18卷 15-28页

作者： Yang Li Jia-qi Zhou Huan-Yan Xu Li-Min Dong Mao-Chang Cao Lian-Wei Shan Li-Guo Jin Xiu-Lan he Shu-Yan qi heilongjiang Provincial Key Laboratory of CO_(2) Resource Utilization and Energy Catalytic Materials School of Materials Science and Chemical EngineeringHarbin University of Science and TechnologyHarbin 150040China

In this work,Fe_(3)O_(4) nanoparticles(NPs)loaded inside and outside halloysite nanotubes(HNTs)were prepared and developed as the heterogeneous Fenton-like catalysts for the removal of representative organic *** results indicated that the samples with Fe_(3)O_(4) NPs loaded outside the HNTs lumen(Fe_(3)O_(4)/HNTs)and inside the HNTs lumen(Fe_(3)O_(4)@HNTs)were successfully *** samples had typical magnetic hysteresis loops,while Fe_(3)O_(4)@HNTs exhibited higher magnetization *** comparative experiments showed that Fe_(3)O_(4)@HNTs had better Fenton-like catalytic ability than that of Fe_(3)O_(4)/HNTs in the degradation of various organic *** Rhodamine B(RhB)as an example,the adsorption thermodynamics and kinetics of RhB onto Fe_(3)O_(4)/HNTs and Fe_(3)O_(4)@HNTs were also *** comparative results demonstrated that the adsorption ability of Fe_(3)O_(4)/HNTs was better than that of Fe_(3)O_(4)@***,the dissolved concentration of Fe^(2+)and production amount of hydroxyl radical(·OH)in the Fe_(3)O_(4)@HNTs-H_(2)O_(2) system were significantly higher than those in the Fe_(3)O_(4)/HNTs-H_(2)O_(2) *** on aforementioned comparison,the nano-confinement effect in the Fe_(3)O_(4)@HNTs-H_(2)O_(2) system was *** work provides meaningful guidance for the cheap and convenient design of nanoreactors for Fenton-like applications.

关键词： Fe_(3)O_(4) halloysite nanotube adsorption Fenton-like reaction mechanism

Dual-assisted high-precision tracking technique for wideband multiplexed signals in new generation GNSS

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Satellite Navigation 2024年第1期5卷 52-73页

作者： Yunhan qi Zheng Yao Mingquan Lu Department of Electronic Engineering Tsinghua UniversityBeijing100084China Beijing National Research Center for Information Science and Technology Beijing100084China

With the evolution of Global Navigation Satellite System(GNSS),new generation GNSS signals have adopted the dual-frequency multiplexing modulation techniques,which jointly modulate multiple signals located on multiple sub-frequencies into a Wideband Multiplexed Signal(WMS).Although WMSs were proposed initially to reduce the complexity of satellite transmitters and improve the transmission efficiency of signals,their multi-component structures and wide root mean square bandwidths introduced by high-frequency subcarriers also provide the possibility to improve the GNSS ranging ***,this paper proposes a Dual-assisted Multi-component Tracking(DMT)technique,which can not only fully use high-frequency subcarriers in WMSs,but also effectively track carrier,subcarrier,and code by jointly utilizing all components in *** this paper,the tracking and ranging performances of DMT are comprehensively analyzed theoretically and by simulation and real *** results show that compared with existing WMS tracking methods,DMT can achieve tracking results with lower tracking jitters and ranging results with higher precision,providing a highly advantageous solution for new generation GNSS signal processing.

关键词： Wideband multiplexed signal Dual-assisted Multi-component High precision tracking

Boosting Electrochemical Urea Synthesis via Constructing Ordered Pd–Zn Active Pair

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Nano-Micro Letters 2024年第11期16卷 529-540页

作者： Weiliang Zhou Chao Feng Xuan Li Xingxing Jiang Lingyan Jing Shuai qi qihua Huo Miaoyuan Lv Xinbao Chen Tianchi Huang Jingwen Zhao Na Meng hengpan Yang qi Hu Chuanxin he College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060GuangdongPeople’s Republic of China School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering Shihezi UniversityShihezi 832003XinjiangPeople’s Republic of China

Electrochemical co-reduction of nitrate(NO_(3)^(-))and carbon dioxide(CO_(2))has been widely regarded as a promising route to produce urea under ambient conditions,however the yield rate of urea has remained ***,we report an atomically ordered intermetallic pallium-zinc(PdZn)electrocatalyst comprising a high density of PdZn pairs for boosting urea *** is found that Pd and Zn are responsible for the adsorption and activation of NO_(3)^(-)and CO_(2),respectively,and thus the co-adsorption and co-activation NO_(3)^(-)and CO_(2) are achieved in ordered PdZn *** importantly,the ordered and well-defined PdZn pairs provide a dual-site geometric structure conducive to the key C-N coupling with a low kinetical barrier,as demonstrated on both operando measurements and theoretical ***,the PdZn electrocatalyst displays excellent performance for the co-reduction to generate urea with a maximum urea Faradaic efficiency of 62.78%and a urea yield rate of 1274.42μg mg^(-1) h^(-1),and the latter is 1.5-fold larger than disordered pairs in PdZn *** work paves new pathways to boost urea electrosynthesis via constructing ordered dual-metal pairs.

关键词： Electrochemical C-N coupling Urea electrosynthesis Intermetallic compounds Geometric structures Active pairs

Prognostic Nutritional Index Associates with the Severity of Silicosis:A Study from a Tertiary Class A Prevention and Treatment Institute for Occupational Diseases in China

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Biomedical and Environmental Sciences 2024年第1期37卷 122-126页

作者： he La Gu LIANG Yun Lai YANG Lu qi YUAN Hua Min Medical laboratory Department Hunan Prevention and Treatment Institute for Occupational DiseasesChangsha 410000HunanChina Laboratory Medicine Department Xiangya HospitalCentral South UniversityChangsha 410013HunanChina

Pneumoconiosis is a group of heterogeneous fibrotic lung diseases caused by inorganic mineral dust and includes coal workers’pneumoconiosis and *** involves diffuse or nodular interstitial pulmonary fibrosis caused by exposure to asbestos or silica *** is thought to have the highest number of silicosis cases,with 6,000 new cases reported annually^([1]).Currently,the clinical diagnosis and monitoring of silicosis relies mainly on a history of occupational exposure and radiological abnormalities^([2]).Therefore,determining further indicators is crucial to reflect the severity of silicosis.

关键词： diagnosis lung diseases

Approximate analytical solutions for threedimensional ascent trajectory of a solid-fuel launch vehicle with time-varying mass flow rate

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Chinese Journal of Aeronautics 2024年第10期37卷 275-293页

作者： qi YU Wanchun CheN Wenbin YU School of Astronautics Beihang UniversityBeijing 102206China

In the scenario that a solid-fuel launch vehicle maneuvers in outer space at high angles of attack and sideslip for energy management,Approximate Analytical Solutions(AAS)for the threedimensional(3D)ascent flight states are derived,which are the only solutions capable of considering time-varying Mass Flow Rate(MFR)at *** uneven MFR makes the thrust vary nonlinearly and thus increases the difficulty of the problem *** AAS are derived based on a 3D Generalized Ascent Dynamics Model(GADM)with a normalized mass as the independent *** simplify some highly nonlinear terms in the GADM,several approximate functions are introduced carefully,while the errors of the approximations relative to the original terms are regarded as minor ***,a finite series with positive and negative exponents,called Exponent-Symmetry Series(ESS),is proposed for function approximation to decrease the highest exponent in the AAS so as to reduce computer round-off *** calculate the ESS coefficients,a method of seeking the Optimal Interpolation Points(OIP)is proposed using the leastsquares-approximation *** to the artful design of the approximations,the GADM can be decomposed into two analytically solvable subsystems by a perturbation method,and thus the AAS are obtained ***,to help implement the AAS,two indirect methods for measuring the remaining mass and predicting the burnout time in flight are put forward using information from *** results verify the superiority of the AAS under the condition of time-varying MFR.

关键词： Approximate analytical solutions 3D ascent trajectory Solid-fuel launch vehicle Uneven thrust Energy management