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Design and Control of an Autonomous Bat-like Perching UAV

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Journal of Bionic Engineering 2024年第3期21卷 1253-1264页

作者： Long bai Wei Wang Xiaohong Chen Yuanxi Sun State Key Laboratory of Mechanical Transmission Chongqing UniversityChongqing400044China

Perching allows small Unmanned Aerial Vehicles(UAVs)to maintain their altitude while significantly extending their flight duration and reducing ***,current research on flying habitats is poorly adapted to unstructured environments,and lacks autonomous capabilities,requiring ideal experimental environments and remote control by *** solve these problems,in this paper,we propose a bat-like UAV perching mechanism by investigating the bat upside-down perching method,which realizes double self-locking in the perching state using the ratchet and four-link dead point *** on this perching mechanism,this study proposes a control strategy for UAVs to track targets and accomplish flight perching autonomously by combining a binocular camera,single-point LiDAR,and pressure *** perching experiments were conducted for crossbar-type objects *** experimental results show that a multirotor UAV equipped with the perching mechanism and sensors can reliably achieve autonomous flight perching and re-flying off the target *** power consumption is reduced to 2.9%of the hovering state when perched on the target object.

关键词： Bio-inspired design Perching mechanism UAV Autonomous flight

How to Construct a Lower Risk FOF Based on Correlation Network? The Method of Principal Component Risk Parity Asset Allocation

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Journal of Systems Science & Complexity 2024年第3期37卷 1052-1079页

作者： bai Wei ZHANG Junting LIU Haifei LIU Kai School of Management and Engineering Nanjing UniversityNanjing 210093China Postdoctoral Workstation of Bank of Jiangsu Co. LtdNanjing 210006China College of Finance Nanjing Agricultural UniversityNanjing 210095China University of Prince Edward Island 550 University AveCharlottetownPE C1A4P3Canada

In order to build a low-risk Fund of Funds(FOF), from the perspective of correlation, the principal component factor is used to improve the traditional risk parity model. Principal component analysis is used to decompose the underlying assets and generate unrelated principal component factors,and then the authors can construct a principal component risk parity portfolio. The proposed empirical results based on China’s mutual fund market show that the performance of principal component risk parity portfolio(PCRPP) is better than that of equal weight portfolio(EWP) and traditional risk parity portfolio(RPP). That is to say, not only the PCRPP in this paper has much lower risk than EWP and RPP, but also slightly better than EWP and RPP in terms of average return. Moreover, the study of dividing the underlying assets shows that the PCRPP in this paper is not sensitive to the underlying assets. The PCRPP in this paper is better than EWP and RPP for both the better performing funds and the worse performing funds. In addition, the empirical results on dynamic portfolio adjustments show that it is not appropriate to adjust asset allocation too frequently when the expected rate of return is calculated using the arithmetic mean.

关键词： Fund of funds(FOF) mutual funds portfolio risk principal component analysis risk parity portfolio

Temperature influence on minimum fluidization velocity:Complexity,mechanism,and solutions

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Particuology 2024年第5期88卷 344-349页

作者： Qingjin Zhang Liangliang Fu Guangwen Xu Dingrong bai Key Laboratory on Resources Chemicals and Material of Ministry of Education Shenyang University of Chemical TechnologyShenyang 110142China School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110142China School of Chemical Engineering University of Science and Technology LiaoningAnshan 114051China

Fluidized-bed reactors are widely employed in various high-temperature industrial ***,it is crucial to understand the temperature effect on various fluidization phenomena,specifically the minimum fluidization velocity(U_(mf))that governs various aspects of fluidized bed *** this study,we comprehensively analyze U_(mf) data from the literature to unravel the complexity and underlying mechanisms of temperature influence on this critical *** research examines experimental data encompassing a wide range of temperatures,pressures,and solid *** analysis reveals that the influence of temperature on U_(mf) is fundamentally determined by the relative importance of hydrodynamic forces and interparticle forces within fluidized beds and is realized by three distinctive temperature-induced changes:gas properties,bed voidage,and physiochemical characteristics of *** this basis,an equation is derived to enable predictions of temperature influences on the minimum fluidization velocity under broad temperature conditions.

关键词： High-temperature gas-solids fluidized beds Minimum fluidization velocity Hydrodynamic forces Interparticle forces Bed voidage

The Influence of CO_(2) Cured Manganese Slag on the Performance and Mechanical Properties of Ultra-High Performance Concrete

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Fluid Dynamics & Materials Processing 2024年第8期20卷 1717-1730页

作者： Ligai bai Guihua Yang School of Architectural Engineering North China Institute of Aerospace EngineeringLangfang065000China

The presence of toxic elements in manganese slag(MSG)poses a threat to the environment due to potential *** CO_(2) curing on MS offers a promising approach to immobilize toxic substances within this material,thereby mitigating their release into the natural *** study investigates the impact of CO_(2) cured MS on various rheological parameters,including slump flow,plastic viscosity(η),and yield shear stress(τ).Additionally,it assesses flexural and compressive strengths(f_(t) and f_(cu)),drying shrinkage rates(DSR),durability indicators(chloride ion migration coefficient(CMC),carbonization depth(CD)),and the leaching behavior of heavy metal *** examination via scanning electron microscopy(SEM)is employed to elucidate the underlying *** results indicate that CO_(2) curing significantly enhances the slump flow of ultra-high performance concrete(UHPC)by up to 51.2%.Moreover,it reduces UHPC’sηandτby rates ranging from 0%to 52.7%and 0%to 40.2%,*** DSR exhibits a linear increase corresponding to the mass ratio of CO_(2) cured ***,CO_(2) curing enhances both f_(t) and f_(cu) of UHPC by up to 28.7%and 17.6%,*** electrical resistance is also improved,showing an increase of up to 53.7%.The relationship between mechanical strengths and electrical resistance follows a cubic *** CO_(2) cured MS demonstrates a notable decrease in the CMC and CD by rates ranging from 0%to 52.6%and 0%to 26.1%,*** reductions of leached chromium(Cr)and manganese(Mn)are up to 576.3%and 1312.7%,***,CO_(2) curing also enhances the compactness of UHPC,thereby demonstrating its potential to improve both mechanical and durability properties.

关键词： CO_(2)curing manganese slag steel fibers mechanical strengths salt action

Decouple charge transfer reactions in the Li-ion battery

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Journal of Energy Chemistry 2024年第5期92卷 759-798页

作者： Yuxuan bai Qiu-An Huang Kai Wu Jiujun Zhang Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghai 200444China Ningde Contemporary Innovation Laboratory Contemporary Amperex Technology Co.LimitedNingde 352100FujianChina

In the development of Li-ion batteries(LIBs)with high energy/power density,long cycle-life,fast charging,and high safety,an insight into charge transfer reactions is *** electrochemical impedance spectroscopy(EIS)is regarded as a powerful diagnosis tool,it is not a direct but an indirect *** respect to this,some critical questions need to be answered:(i)why EIS can reflect the kinetics of charge transfer reactions;(ii)what the inherent logical relationship between impedance models under different physical scenes is;(iii)how charge transfer reactions compete with each other at multiple *** work aims at answering these questions via developing a theory framework so as to mitigate the blindness and uncertainty in unveiling charge transfer reactions in *** systematically answer the above questions,this article is organized into a three-in-one(review,tutorial,and research)type and the following contributions are made:(i)a brief review is given for impedance model development of the LIBs over the past half century;(ii)an open source code toolbox is developed based on the unified impedance model;(iii)the competive mechanisms of charge transfer reactions are unveiled based on the developed EIS-Toolbox@*** work not only clarifies theoretical fundamentals,but also provides an easy-to-use open source code for EIS-Toolbox@LIB to optimize fast charge/discharge,mitigate cycle aging,and improve energy/power density.

关键词： Electrochemical impedance spectroscopy Unified impedance model Charge transfer reactions Solid/electrolyte diffusion Porous electrode EIS-Toolbox@LIB

Washed microbiota transplantation for Crohn’s disease:A metagenomic,metatranscriptomic,and metabolomic-based study

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World Journal of Gastroenterology 2024年第11期30卷 1572-1587页

作者： Shi-Ju Chen Da-Ya Zhang Xia Wu Fa-Ming Zhang Bo-Ta Cui Yi-Hao Huang Zu-Lun Zhang rui Wang Fei-Hu bai Graduate School Hainan Medical UniversityHaikou 571199Hainan ProvinceChina Department of Microbiota Medicine&Medical Center for Digestive Diseases The Second Affiliated Hospital of Nanjing Medical UniversityNanjing 210011Jiangsu ProvinceChina Department of Gastroenterology The Second Affiliated Hospital of Hainan Medical UniversityHaikou 570216Hainan ProvinceChina

BACKGROUND Fecal microbiota transplantation(FMT)is a promising therapeutic approach for treating Crohn’s disease(CD).The new method of FMT,based on the automatic washing process,was named as washed microbiota transplantation(WMT).Most existing studies have focused on observing the clinical ***,the mechanism of action of FMT for the effective management of CD-particularly in-depth multi-omics analysis involving the metagenome,metatranscriptome,and metabolome-has not yet been *** To assess the efficacy of WMT for CD and explore alterations in the microbiome and metabolome in response to *** We conducted a prospective,open-label,single-center clinical *** CD patients underwent *** clinical responses(defined as a decrease in their CD Activity Index score of>100 points)and their microbiome(metagenome,metatranscriptome)and metabolome profiles were evaluated three months after the *** Seven of the 11 patients(63.6%)showed an optimal clinical response three months *** microbiome diversity significantly increased after WMT,consistent with improved clinical *** of the metagenome and metatranscriptome analyses revealed consistent alterations in certain strains,such as Faecalibac-terium prausnitzii,Roseburia intestinalis,and Escherichia *** addition,metabolomics analyses demonstrated that CD patients had elevated levels of various amino acids before treatment compared to the ***,levels of vital amino acids that may be associated with disease progression(e.g.,L-glutamic acid,gamma-glutamyl-leucine,and prolyl-glutamine)were reduced after *** WMT demonstrated therapeutic efficacy in CD treatment,likely due to the effective reconstruction of the patient’s ***-omics techniques can effectively help decipher the potential mechanisms of WMT in treating CD.

关键词： Crohn’s disease Clinical trials Fecal microbiota transplant Metagenome Metatranscriptome Metabolome

GCAGA: A Gini Coefficient-Based Optimization Strategy for Computation Offloading in Multi-User-Multi-Edge MEC System

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Computers, Materials & Continua 2024年第6期79卷 5083-5103页

作者： Junqing bai Qiuchao Dai Yingying Li School of Computing Xi’an Shiyou UniversityXi’an710065China Product Center Wingtech Technology(Wuxi)Co.Wuxi214028China

To support the explosive growth of Information and Communications Technology(ICT),Mobile Edge Comput-ing(MEC)provides users with low latency and high bandwidth service by offloading computational tasks to the network’s ***,resource-constrained mobile devices still suffer from a capacity mismatch when faced with latency-sensitive and compute-intensive emerging *** address the difficulty of running computationally intensive applications on resource-constrained clients,a model of the computation offloading problem in a network consisting of multiple mobile users and edge cloud servers is studied in this *** a user benefit function EoU(Experience of Users)is proposed jointly considering energy consumption and time *** EoU maximization problem is decomposed into two steps,i.e.,resource allocation and offloading *** offloading decision is usually given by heuristic algorithms which are often faced with the challenge of slow convergence and poor ***,a combined offloading algorithm,i.e.,a Gini coefficient-based adaptive genetic algorithm(GCAGA),is proposed to alleviate the *** proposed algorithm optimizes the offloading decision by maximizing EoU and accelerates the convergence with the Gini *** simulation compares the proposed algorithm with the genetic algorithm(GA)and adaptive genetic algorithm(AGA).Experiment results show that the Gini coefficient and the adaptive heuristic operators can accelerate the convergence speed,and the proposed algorithm performs better in terms of convergence while obtaining higher *** simulation code of the proposed algorithm is available:https://***/Grox888/Mobile_Edge_Computing/tree/GCAGA.

关键词： Mobile edge computing multi-user-multi-edge joint optimization Gini coefficient adaptive genetic algorithm

Supplementation with dimethylglycine sodium salt improves lipid metabolism disorder in intrauterine growth-retarded pigs

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ANIMAL NUTRITION 2024年第3期18卷 191-202页

作者： bai, Kaiwen Jiang, Luyi Wang, Tian Zhejiang Univ Sci & Technol Sch Biol & Chem Engn Hangzhou 310023 Peoples R China nanjing Agr Univ Coll Anim Sci & Technol Nanjing 210095 Peoples R China Zhejiang Shuren Univ Coll Biol & Environm Engn Hangzhou 310023 Peoples R China Zhejiang Univ Inst Dairy Sci Coll Anim Sci Minist EducKey Lab Mol Anim Nutr Hangzhou Peoples R China

This study aims to elucidate the mechanism of lipid metabolism disorder in intrauterine growth retardation (IUGR) pigs and the potential alleviating effects of dimethylglycine sodium salt (DMG-na). A total of 60 male newborn piglets were selected for this study. Within each litter, one normal birth weight (NBW) male piglet (1.53 +/- 0.04 kg) and two IUGR male piglets (0.76 +/- 0.06 kg) were chosen based on their birth weight. The piglets were divided into three groups for the study: NBW pigs received a PBS gavage and a common basal diet (NBW-C group), IUGR pigs received the same PBS gavage and common basal diet (IUGR-C group), and IUGR pigs received a 70-mg DMG-na gavage along with a common basal diet supplemented with 0.1% DMG-na (IUGR-D group). At 150 d of age, all piglets underwent euthanasia by exsanguination following electrical stunning, after which plasma, liver, and longissimus dorsi (LM) samples were promptly collected. The IUGR-D group demonstrated improvements in plasma parameters (P naD & thorn;, naD & thorn;/naDH, adenosine triphosphate, and mtDna values, and lower naDH values in the liver and LM. Additionally, meat quality parameters showed improvement (P < 0.05), with higher pH 24 h and a* values, and lower drip loss 48 h, L*, and b* values. The expressions of lipid metabolism and mitochondrial function-relate

关键词： Intrauterine growth retardation Pig Lipid metabolism Mitochondrial function Dimethylglycine sodium salt SKELETAL-MUSCLE MITOCHONDRIAL DYSFUNCTION PROMOTES

SCAB1 coordinates sequential Ca^(2+) and ABA signals during osmotic stress induced stomatal closure in Arabidopsis

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Science China(Life Sciences) 2024年第1期67卷 1-18页

作者： Tianren Zhang Li bai Yan Guo State Key Laboratory of Plant Environmental Resilience College of Biological SciencesChina Agricultural UniversityBeijing 100193China

Hyperosmotic stress caused by drought is a detrimental threat to plant growth and agricultural productivity due to limited water *** are gateways of transpiration and gas exchange,the swift adjustment of stomatal aperture has a strong influence on plant drought *** intensive investigations of stomatal closure during drought stress in past decades,little is known about how sequential signals are integrated during complete ***,we discovered that the rapid Ca^(2+) signaling and subsequent abscisic acid(ABA)signaling contribute to the kinetics of both F-actin reorganizations and stomatal closure in Arabidopsis thaliana,while STOMATAL CLOSURE-RELATED ACTIN BINDING PROTEIN1(SCAB1)is the molecular switch for this entire *** the early stage of osmotic shock responses,swift elevated calcium signaling promotes SCAB1 phosphorylation through calcium sensors CALCIUM DEPENDENT PROTEIN KInaSE3(CPK3)and *** phosphorylation restrained the microfilament binding affinity of SCAB1,which bring about the Factin disassembly and stomatal closure *** the osmotic stress signal continued,both the kinase activity of CPK3 and the phosphorylation level of SCAB1 attenuated *** further found that ABA signaling is indispensable for these attenuations,which presumably contributed to the actin filament reassembly process as well as completion of stomatal ***,the dynamic changes of SCAB1 phosphorylation status are crucial for the kinetics of stomatal *** together,our results support a model in which SCAB1 works as a molecular switch,and directs the microfilament rearrangement through integrating the sequentially generated Ca^(2+) and ABA signals during osmotic stress induced stomatal closure.

关键词： calcium signal ABA stomatal movement microfilaments kinase