检索结果-南通市图书馆

Neighborhood predictors of short sleep duration and bedtime irregularity among children in the United States: results from the 2019-2020 National Surveyof Children's Health

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Pediatrics 2024年第1期20卷 73-81页

作者： ying Dai Jianghong liu School of Nursing University of Pennsylvania418 Curie Blvd.Room 426Claire M.Fagin HallPhiladelphiaPA19104-6096USA

Background Environmental factors may contribute to short sleep duration and irregular bedtime in *** factors and children's sleep duration and bedtime regularity remain a less investigated *** aim of this study was to investigate the national and state-level proportions of children with short sleep duration and irregular bedtime and their neighborhood *** A total of 67,598 children whose parents completed the National Survey of Children's Health in 2019-2020 were included in the ***-weighted Poisson regression was used to explore the neighborhood predictors of children's short sleep duration and irregular *** The prevalence of short sleep duration and irregular bedtime among children in the United States(US)was 34.6%[95%confidence interval(CI)=33.8%-35.4%]and 16.4%(95%CI=15.6%-17.2%)in 2019-2020,*** neighborhoods,supportive neighborhoods,and neighborhoods with amenities were found to be protective factors against children's short sleep duration,with risk ratios ranging between 0.92 and 0.94,P<*** with detracting elements were associated with an increased risk of short sleep duration[risk ratio(RR)=1.06,95%CI=1.00-1.12]and irregular bedtime(RR=1.15,95%CI=1.03-1.28).Child race/ethnicity moderated the relationship between neighborhood with amenities and short *** Insufficient sleep duration and irregular bedtime were highly prevalent among US children.A favorable neighborhood environment can decrease children's risk of short sleep duration and irregular *** the neighborhood environment has implications for children's sleep health,especially for children from minority racial/ethnic groups.

关键词： Child National Survey of Children's Health Neighborhood.Sleep Social determinants of health

The important role of Turbidity Maximum Zone in sedimentary dynamic of estuarine mangrove swamp

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Earth Science 2024年第1期18卷 219-226页

作者： Tao liu ying.liu Baoqing HU Key laboratory of Environment Change and Resources Use in Beibu Gulf(Ministry of Education) Nanning Normal UniversityNanning 530001China School of Civil Engineering and Architecture Guangxi UniversityNanning 530004China

Sedimentation is a key process affecting wetland sustainability and carbon burial *** context of sea level rise,climate change and human activities,further understanding about the sedimentary dynamic in wetland is critical in predicting the landscape evolution or the change in carbon burial *** this study,based on the field hydrological observation in a mangrove system in the Nanliu River estuary,we found the net flux of suspended sediment to mangrove is 39−72 kg/m in tidal cycles with Turbidity Maximum Zone(TMZ)forming in surface layer and only is 9−18 kg/m in tidal cycles without *** higher net flux of suspended sediment to mangrove in tidal cycles with TMZ forming in surface layer is attributed to high SSC in rising tide and intense flocculation in *** significant discrepancy in sedimentation rate in the mangrove patches also can be explained by the probability of TMZ forming in the surface layer of *** future,rapid sea level rising may lead to the change of TMZ pattern in estuary,which will result in non-negligible variation in sedimentation rate in *** to the present data of sedimentation rate in wetlands,the fragility of wetlands in river estuary may be miscalculated.

关键词： mangrove wetland sedimentation Turbidity Maximum Zone Nanliu River

A Novel Extremum Seeking Control to Enhance Convergence and Robustness in the Presence of Nonlinear Dynamic Sensors

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2024年第1期37卷 3-21页

作者： liu Hengchang TAN ying OETOMO Denny School of Electrical Mechanical and Infrastructure EngineeringThe University of MelbourneParkville VIC 3010Australia

This paper focuses on optimizing an unknown cost function through extremum seeking(ES)control in the presence of a slow nonlinear dynamic sensor responsible for measuring the *** contrast to traditional perturbation-based ES control,which often suffers from sluggish convergence,the proposed method eliminates the time-scale separation between sensor dynamics and ES control by using the relative degree of the nonlinear sensor *** improve the convergence rate,the authors incorporate high-frequency dither signals and a *** enhance the robustness with the existence of rapid disturbances,an off-the-shelf linear high-gain differentiator is *** first result demonstrates that,for any desired convergence rate,with properly tuned parameters for the proposed ES algorithm,the input of the cost function can converge to an arbitrarily small neighborhood of the optimal solution,starting from any initial condition within any given compact ***,the second result shows the robustness of the proposed ES control in the presence of sufficiently fast,zero-mean periodic *** results substantiate these theoretical findings.

关键词： Averaging extremum seeking optimization singular perturbation time-scale separation

A Converse Theorem for Split SO_(2l) over Finite Fields

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第3期40卷 731-771页

作者： Alexander HAZELTINE Bai ying.liu Department of Mathematics Purdue University150 N.University St.West LafayetteIN 47907USA E-mail:ahazelti@purdue.edu liu2053@purdue.edu

We prove a converse theorem for split even special orthogonal groups over finite *** is the only case left on converse theorems of classical groups and the difficulty is the existence of the outer automorphism. In thi... 详细信息

关键词： Converse theorems generic cuspidal representations even special orthogonal groups

Bandgap adjustment of a sandwich-like acoustic metamaterial plate with a frequency-displacement feedback control method

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第10期45卷 1807-1820页

作者： Jianing liu Jinqiang LI ying WU School of Aerospace Engineering Xi'an Jiaotong University College of Aerospace and Civil Engineering Harbin Engineering University

Several types of acoustic metamaterials composed of resonant units have been developed to achieve low-frequency bandgaps. In most of these structures, bandgaps are determined by their geometric configurations and material properties. This paper presents a frequency-displacement feedback control method for vibration suppression in a sandwich-like acoustic metamaterial plate. The band structure is theoretically derived using the Hamilton principle and validated by comparing the theoretical calculation results with the finite element simulation results. In this method, the feedback voltage is related to the displacement of a resonator and the excitation frequency. By applying a feedback voltage on the piezoelectric fiber-reinforced composite(PFRC) layers attached to a cantilever-mass resonator, the natural frequency of the resonator can be adjusted. It ensures that the bandgap moves in a frequency-dependent manner to keep the excitation frequency within the bandgap. Based on this frequency-displacement feedback control strategy, the bandgap of the metamaterial plate can be effectively adjusted, and the vibration of the metamaterial plate can be significantly suppressed.

关键词： 35B34 74H45 acoustic metamaterial electromechanical coupling Hamilton principle local resonance O328 vibration control

Homoclinic Solutions for a Class of Perturbed Fractional Hamiltonian Systems with Subquadratic Conditions

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第5期40卷 1177-1196页

作者： ying LUO Fei GUO Yan liu School of Mathematics Tianjin UniversityTianjin 300354P.R.China Tianjin Key Laboratory of Brain-Inspired Intelligence Technology Tianjin300354P.R.China

In this paper,we consider the following perturbed fractional Hamiltonian systems{tD_(∞)^(α)(_(-∞)D_(t)^(α)u(t))+L(t)u(t)=■_(u)W(t,u(t))+■(u)G(t,u(t)),t∈R,u∈H^(α)(R,R^(N)),whereα∈(1/2,1],L∈C(R,R^(N×N))is symmetric and not necessarily required to be positive definite,W∈C1(R×R^(N,R))is locally subquadratic and locally even near the origin,and perturbed term G∈C1(R×R^(N,R))maybe has no parity in *** the perturbed method improved by the authors,a sequence of nontrivial homo clinic solutions is obtained,which generalizes previous results.

关键词： Perturbed fractional Hamiltonian systems subquadratic condition perturbed method homoclinic solutions multiplicity

Phylogenetic study on Scenedesmacae with the description of a new genus Coccoidesmus ***.(Chlorophyceae,Chlorophyta)and chloroplast genome analyses

在线全文

学校读者我要写书评

暂无评论

Journal of Oceanology and Limnology 2024年第4期42卷 1272-1285页

作者： Qinghua WANG ying HOU Yanhui LI ying SHI Guoxiang liu College of Biological Sciences and Technology Taiyuan Normal UniversityJinzhong 030619China Shanxi Vocational University of Engineering Science and Technology Jinzhong 030619China Key Laboratory of Algal Biology Institute of HydrobiologyChinese Academy of SciencesWuhan 430072China

Members of the family Scenedesmaceae are some of the most common algal taxa in inland ecosystems,and they are widely distributed in freshwaters,aerial,and sub-aerial *** the continuous updating of methods,the classic morphological taxonomy of this family needs to be *** recent years,many genera of Scenedesmaceae have been established via the use of molecular *** phylogenetic relationships within Scenedesmaceae were analyzed using different molecular markers and morphological data,and the new freshwater genus Coccoidesmus Wang,Hou et liu *** *** new species in this genus were also *** analysis based on tufA genes revealed that the new genus formed an independent clade closely related to ***,these two genera are characterized by significant morphological differences in colony arrangement and cell *** chloroplast genome of the type species was assembled and annotated,and analyses of genome structure and sequences were *** genome data could help clarify the phylogenetic relationships within this family.

关键词： phylogenetic Scenedesmaceae Coccoidesmus morphology chloroplast genome

Structural Engineering of Hierarchical Magnetic/Carbon Nanocomposites via In Situ Growth for High-Efficient Electromagnetic Wave Absorption

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2024年第9期16卷 262-278页

作者： Xianyuan liu Jinman Zhou ying Xue Xianyong Lu Key Laboratory of Bio‑Inspired Smart Interfacial Science and Technology of Ministry of Education School of ChemistryBeihang UniversityBeijing 100191People’s Republic of China

Materials exhibiting high-performance electromagnetic wave absorption have garnered considerable scientific and technological attention,yet encounter significant *** new materials and innovative structural design concepts is crucial for expanding the application field of electromagnetic wave ***,hierarchical structure engineering has emerged as a promising approach to enhance the physical and chemical properties of materials,providing immense potential for creating versatile electromagnetic wave absorption ***,an exceptional multi-dimensional hierarchical structure was meticulously devised,unleashing the full microwave attenuation capabilities through in situ growth,selfreduction,and multi-heterogeneous interface *** hierarchical structure features a three-dimensional carbon framework,where magnetic nanoparticles grow in situ on the carbon skeleton,creating a necklace-like ***,magnetic nanosheets assemble within this *** impedance matching was achieved by precisely adjusting component proportions,and intelligent integration of diverse interfaces bolstered dielectric *** obtain Fe_(3)O_(4)-Fe nanoparticles/carbon nanofibers/Al-Fe_(3)O_(4)-Fe nanosheets composites demonstrated outstanding performance with a minimum reflection loss(RLmin)value of−59.3 dB and an effective absorption bandwidth(RL≤−10 dB)extending up to 5.6 GHz at 2.2 *** notable accomplishments offer fresh insights into the precision design of high-efficient electromagnetic wave absorption materials.

关键词： Electromagnetic wave absorption Hierarchical structure In situ growth Self-reduction

Non-contact and full-field online monitoring of curing temperature during the in-situ heating process based on deep learning

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2024年第1期12卷 167-176页

作者： Qiang-Qiang liu Shu-Ting liu ying-Guang Li Xu liu Xiao-Zhong Hao College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and AstronauticsNanjing210016People’s Republic of China School of Mechanical and Power Engineering Nanjing Tech UniversityNanjing211816People’s Republic of China

Online monitoring of the curing temperature field is essential to improving the quality and efficiency of the manufacturing process of composite *** embedded sensor-based technologies have difficulty monitoring the full temperature field or have to introduce heterogeneous items that could have an undesired impact on the *** this paper,a non-contact,full-field monitoring method based on deep learning that predicts the internal temperature field of composite parts in real time using surface temperature measurements of auxiliary materials is *** the proposed method,an average temperature monitoring accuracy of 97%is achieved in various heating *** addition,this method also demonstrates satisfying feasibility when a stronger thermal barrier covers the *** method was experimentally validated during the self-resistance electric heating process,in which the monitoring accuracy reached 93.1%.This method can potentially be applied to automated manufacturing and process control in the composites industry.

关键词： Online monitoring Curing temperature field Deep learning(DL) In-situ heating