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Voluntary wheel running ameliorated the deleterious effects of high-fat diet on glucose metabolism,gut microbiota and microbial-associated metabolites
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作者 Ling Zhang Wenyu Zou +4 位作者 Yongyan Hu Honghua Wu Ying Gao Junqing Zhang Jia Zheng 《Food Science and Human Wellness》 SCIE CSCD 2024年第3期1672-1684,共13页
Exercise training is critical for the early prevention and treatment of obesity and diabetes mellitus.However,the mechanism with gut microbiota and fecal metabolites underlying the effects of voluntary wheel running o... Exercise training is critical for the early prevention and treatment of obesity and diabetes mellitus.However,the mechanism with gut microbiota and fecal metabolites underlying the effects of voluntary wheel running on high-fat diet induced abnormal glucose metabolism has not been fully elaborated.C57BL/6 male mice were randomly assigned to 4 groups according to diets(fed with normal chow diet or high-fat diet)and running paradigm(housed in static cage or with voluntary running wheel).An integrative 16S rDNA sequencing and metabolites profiling was synchronously performed to characterize the effects of voluntary wheel running on gut microbiota and metabolites.It showed that voluntary wheel running prevented the detrimental effects of high-fat feeding on glucose metabolism 16S rDNA sequencing showed remarkable changes in Rikenella and Marvinbryantia genera.Metabolic profiling indicated multiple altered metabolites,which were enriched in secondary bile acid biosynthesis signaling.In conclusion,our study indicated that voluntary wheel running significantly improved glucose metabolism and counteracted the deleterious effects of high-fat feeding on body weight and glucose intolerance.We further found that voluntary wheel running could integratively program gut microbiota composition and fecal metabolites changes,and may regulate muricholic acid metabolism and secondary bile acid biosynthesis in high-fat fed mice. 展开更多
关键词 High-fat diet Voluntary wheel running Gut microbiota Metabolomics Glucose metabolism
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Influence of pier height on the safety of trains running on high-speed railway bridges during earthquakes
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作者 NIE Yu-tao GUO Wei +8 位作者 JIANG Li-zhong YU Zhi-wu ZENG Chen WANG Yang HE Xu-en REN Shao-xun HUANG Ren-qiang LIANG Guang-yue LI Chang-qing 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期2102-2115,共14页
Sudden earthquakes pose a threat to the running safety of trains on high-speed railway bridges,and the stiffness of piers is one of the factors affecting the dynamic response of train-track-bridge system.In this paper... Sudden earthquakes pose a threat to the running safety of trains on high-speed railway bridges,and the stiffness of piers is one of the factors affecting the dynamic response of train-track-bridge system.In this paper,a experiment of a train running on a high-speed railway bridge is performed based on a dynamic experiment system,and the corresponding numerical model is established.The reliability of the numerical model is verified by experiments.Then,the experiment and numerical data are analyzed to reveal the pier height effects on the running safety of trains on bridges.The results show that when the pier height changes,the frequency of the bridge below the 30 m pier height changes greater;the increase of pier height causes the transverse fundamental frequency of the bridge close to that of the train,and the shaking angle and lateral displacement of the train are the largest for bridge with 50 m pier,which increases the risk of derailment;with the pier height increases from 8 m to 50 m,the derailment coefficient obtained by numerical simulations increases by 75% on average,and the spectral intensity obtained by experiments increases by 120% on average,two indicators exhibit logarithmic variation. 展开更多
关键词 pier height high-speed railway bridge running safety numerical model
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Acute effect of foot strike patterns on in vivo tibiotalar and subtalar joint kinematics during barefoot running
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作者 Dongqiang Ye Lu Li +4 位作者 Shen Zhang Songlin Xiao Xiaole Sun Shaobai Wang Weijie Fu 《Journal of Sport and Health Science》 SCIE CSCD 2024年第1期108-117,共10页
Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patte... Background:Foot kinematics,such as excessive eversion and malalignment of the hindfoot,are believed to be associated with running-related injuries.The maj ority of studies to date show that different foot strike patterns influence these specific foot and ankle kinematics.However,technical deficiencies in traditional motion capture approaches limit knowledge of in vivo joint kinematics with respect to rearfoot and forefoot strike patterns(RFS and FFS,respectively).This study uses a high-speed dual fluoroscopic imaging system(DFIS)to determine the effects of different foot strike patterns on 3D in vivo tibiotalar and subtalar joints kinematics.Methods:Fifteen healthy male recreational runners underwent foot computed tomography scanning for the construction of 3-dimensional models.A high-speed DFIS(100 Hz)was used to collect 6 degrees of freedom kinematics for participants’tibiotalar and subtalar joints when they adopted RFS and FFS in barefoot condition.Results:Compared with RFS,FFS exhibited greater internal rotation at 0%-20%of the stance phase in the tibiotalar joint.The peak internal rotation angle of the tibiotalar joint under FFS was greater than under RFS(p<0.001,Cohen’s d=0.92).RFS showed more dorsiflexion at 0%-20%of the stance phase in the tibiotalar joint than FFS.RFS also presented a larger anterior translation(p<0.001,Cohen’s d=1.28)in the subtalar joint at i nitial contact than FFS.Conclusion:Running with acute barefoot FFS increases the internal rotation of the tibiotalar joint in the early stance.The use of high-speed DFIS to quantify the movement of the tibiotalar and subtalar joint was critical to revealing the effects of RF S and FFS during running. 展开更多
关键词 Foot strike patterns High-speed dual fluoroscopic imaging system In vivo kinematics running
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Enhancement of motor functional recovery in thoracic spinal cord injury: voluntary wheel running versus forced treadmill exercise
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作者 Do-Hun Lee Dan Cao +4 位作者 Younghye Moon Chen Chen Nai-Kui Liu Xiao-Ming Xu Wei Wu 《Neural Regeneration Research》 SCIE CAS 2025年第3期836-844,共9页
Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery ... Spinal cord injury necessitates effective rehabilitation strategies, with exercise therapies showing promise in promoting recovery. This study investigated the impact of rehabilitation exercise on functional recovery and morphological changes following thoracic contusive spinal cord injury. After a 7-day recovery period after spinal cord injury, mice were assigned to either a trained group(10 weeks of voluntary running wheel or forced treadmill exercise) or an untrained group. Bi-weekly assessments revealed that the exercise-trained group, particularly the voluntary wheel exercise subgroup, displayed significantly improved locomotor recovery, more plasticity of dopaminergic and serotonin modulation compared with the untrained group. Additionally, exercise interventions led to gait pattern restoration and enhanced transcranial magnetic motor-evoked potentials. Despite consistent injury areas across groups, exercise training promoted terminal innervation of descending axons. In summary, voluntary wheel exercise shows promise for enhancing outcomes after thoracic contusive spinal cord injury, emphasizing the role of exercise modality in promoting recovery and morphological changes in spinal cord injuries. Our findings will influence future strategies for rehabilitation exercises, restoring functional movement after spinal cord injury. 展开更多
关键词 behavioral assessment motor function neural plasticity running wheel exercise spinal cord injury treadmill exercise voluntary exercise
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A novel refined dynamic model of high-speed maglev train-bridge coupled system for random vibration and running safety assessment
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作者 MAO Jian-feng LI Dao-hang +3 位作者 YU Zhi-wu CAI Wen-feng GUO Wei ZHANG Guang-wen 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2532-2544,共13页
Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can b... Running safety assessment and tracking irregularity parametric sensitivity analysis of high-speed maglev train-bridge system are of great concern,especially need perfect refinement models in which all properties can be well characterized based on various stochastic excitations.A three-dimensional refined spatial random vibration analysis model of high-speed maglev train-bridge coupled system is established in this paper,in which multi-source uncertainty excitation can be considered simultaneously,and the probability density evolution method(PDEM)is adopted to reveal the system-specific uncertainty dynamic characteristic.The motion equation of the maglev vehicle model is composed of multi-rigid bodies with a total 210-degrees of freedom for each vehicle,and a refined electromagnetic force-air gap model is used to account for the interaction and coupling effect between the moving train and track beam bridges,which are directly established by using finite element method.The model is proven to be applicable by comparing with Monte Carlo simulation.By applying the proposed stochastic framework to the high maglev line,the random dynamic responses of maglev vehicles running on the bridges are studied for running safety and stability assessment.Moreover,the effects of track irregularity wavelength range under different amplitude and running speeds on the coupled system are investigated.The results show that the augmentation of train speed will move backward the sensitive wavelength interval,and track irregularity amplitude influences the response remarkably in the sensitive interval. 展开更多
关键词 maglev train-bridge interaction electromagnetic force-air gap model stochastic dynamic analysis running safety assessment probability density evolution method
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SmartMicro Grid Energy System Management Based on Optimum Running Cost for Rural Communities in Rwanda
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作者 Fabien Mukundufite Jean Marie Vianney Bikorimana Alexander Kyaruzi Lugatona 《Energy Engineering》 EI 2024年第7期1805-1821,共17页
The governmental electric utility and the private sector are joining hands to meet the target of electrifying all households by 2024.However,the aforementioned goal is challenged by households that are scattered in re... The governmental electric utility and the private sector are joining hands to meet the target of electrifying all households by 2024.However,the aforementioned goal is challenged by households that are scattered in remote areas.So far,Solar Home Systems(SHS)have mostly been applied to increase electricity access in rural areas.SHSs have continuous constraints to meet electricity demands and cannot run income-generating activities.The current research presents the feasibility study of electrifying Remera village with the smart microgrid as a case study.The renewable energy resources available in Remera are the key sources of electricity in that village.The generation capacity is estimated based on the load profile.The microgrid configurations are simulated with HOMER,and the genetic algorithm is used to analyze the optimum cost.By analyzing the impact of operation and maintenance costs,the results show that the absence of subsidies increases the levelized cost of electricity(COE)five times greater than the electricity price from the public utility.The microgrid made up of PV,diesel generator,and batteries proved to be the most viable solution and ensured continuous power supply to customers.By considering the subsidies,COE reaches 0.186$/kWh,a competitive price with electricity from public utilities in Rwanda. 展开更多
关键词 Load demand load profile optimum running cost power demand satisfaction smart meters and smart micro grid
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Review of Research on English Translation of Chinese Running Sentences
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作者 ZHANG Wen-hui 《Journal of Literature and Art Studies》 2024年第7期624-627,共4页
In order to convey complete meanings,there is a phenomenon in Chinese of using multiple running sentences.Xu Jingning(2023,p.66)states,“In communication,a complete expression of meaning often requires more than one c... In order to convey complete meanings,there is a phenomenon in Chinese of using multiple running sentences.Xu Jingning(2023,p.66)states,“In communication,a complete expression of meaning often requires more than one clause,which is common in human languages.”Domestic research on running sentences includes discussions on defining the concept and structural features of running sentences,sentence properties,sentence pattern classifications and their criteria,as well as issues related to translating running sentences into English.This article primarily focuses on scholarly research into the English translation of running sentences in China,highlighting recent achievements and identifying existing issues in the study of running sentence translation.However,by reviewing literature on the translation of running sentences,it is found that current research in the academic community on non-core running sentences is limited.Therefore,this paper proposes relevant strategies to address this issue. 展开更多
关键词 Chinese running sentences TOPICS English-Chinese translation
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Safety of the express freight train running over a long-span bridge
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作者 Jingcheng Wen Yihao Qin +1 位作者 Ye Bai Xiaoqing Dong 《Railway Sciences》 2024年第4期469-479,共11页
Purpose-Express freight transportation is in rapid development currently.Owing to the higher speed of express freight train,the deformation of the bridge deck worsens the railway line condition under the action of win... Purpose-Express freight transportation is in rapid development currently.Owing to the higher speed of express freight train,the deformation of the bridge deck worsens the railway line condition under the action of wind and train moving load when the train runs over a long-span bridge.Besides,the blunt car body of vehicle has poor aerodynamic characteristics,bringing a greater challenge on the running stability in the crosswind.Design/methodology/approach-In this study,the aerodynamic force coefficients of express freight vehicles on the bridge are measured by scale model wind tunnel test.The dynamic model of the train-long-span steel truss bridge coupling system is established,and the dynamic response as well as the running safety of vehicle are evaluated.Findings-The results show that wind speed has a significant influence on running safety,which is mainly reflected in the over-limitation of wheel unloading rate.The wind speed limit decreases with train speed,and it reduces to 18.83 m/s when the train speed is 160 km/h.Originality/value-This study deepens the theoretical understanding of the interaction between vehicles and bridges and proposes new methods for analyzing similar engineering problems.It also provides a new theoretical basis for the safety assessment of express freight trains. 展开更多
关键词 Express freight train Long-span bridge CROSSWIND Wind tunnel test running safety Paper type Research paper
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Does orthotics use improve comfort,speed,and injury rate during running?A randomised control trial
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作者 Alice E Fortune Jonathan M G Sims George Ampat 《World Journal of Orthopedics》 2023年第5期348-361,共14页
BACKGROUND Running is a hugely popular sport.Unfortunately,running-related injury(RRI)rates are high,particularly amongst amateur and recreational runners.Finding ways to reduce RRI rates and maximise comfort and perf... BACKGROUND Running is a hugely popular sport.Unfortunately,running-related injury(RRI)rates are high,particularly amongst amateur and recreational runners.Finding ways to reduce RRI rates and maximise comfort and performance for runners is important.Evidence regarding whether orthotics can successfully improve these parameters is limited and contradicting.Further research is required to provide runners with clearer guidance on the usefulness of orthotics.AIM To investigate the effect of Aetrex Orthotics on comfort,speed and RRI rates during recreational running.METHODS One hundred and six recreational runners were recruited on a voluntary basis via running clubs and social media pages and randomised into either the intervention or control group.Participants in the intervention group ran with Aetrex L700 Speed Orthotics inserted in their usual running shoes,whilst participants in the control group ran in their usual running shoes with no orthotics.The study ran for an 8-wk period.Participants provided data relating to running comfort,distance,and time during weeks 3-6.Participants provided data relating to any RRIs they sustained during all 8 wks.Running distance and time were used to calculate running speed in miles per hour(mph).For each outcome variable,95%confidence intervals and P values were calculated to assess the statistical significance between the groups.For comfort and speed data,univariate multi-level analysis was performed,and for outcome variables with significant between group differences,multi-level multivariate analysis was performed to evaluate any confounding effects of gender and age.RESULTS Ninety-four participants were included in the final analysis(drop-out rate=11%).Comfort and speed from 940 runs and 978 injury data reports were analysed.Participants who ran with orthotics reported,on average,speeds 0.30 mph faster(P=0.20)and comfort scores 1.27 points higher(P≤0.001)than participants who ran with no orthotics.They were also 2.22 times less likely to sustain an injury(P=0.08)than participants who ran with no orthotics.However,findings were only significant for comfort and not for speed or injury rates.Age and gender were found to be significant predictors of comfort.However,the improvements in comfort reported by participants who ran with orthotics were still significant after adjusting for age and gender.CONCLUSION This study found orthotics to improve comfort and speed and prevent RRIs whilst running.However,these findings were only statistically significant for comfort. 展开更多
关键词 running Foot orthoses running related injuries PAIN Patient comfort Athletic performance
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Free running period affected by network structures of suprachiasmatic nucleus neurons exposed to constant light
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作者 周建 顾长贵 +1 位作者 宋雨轩 许艳 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期566-572,共7页
Exposed to the natural light-dark cycle,24 h rhythms exist in behavioral and physiological processes of living beings.Interestingly,under constant darkness or constant light,living beings can maintain a robust endogen... Exposed to the natural light-dark cycle,24 h rhythms exist in behavioral and physiological processes of living beings.Interestingly,under constant darkness or constant light,living beings can maintain a robust endogenous rhythm with a free running period(FRP)close to 24 h.In mammals,the circadian rhythm is coordinated by a master clock located in the suprachiasmatic nucleus(SCN)of the brain,which is composed of about twenty thousand self-oscillating neurons.These SCN neurons form a heterogenous network to output a robust rhythm.Thus far,the exact network topology of the SCN neurons is unknown.In this article,we examine the effect of the SCN network structure on the FRP when exposed to constant light by a Poincare model.Four typical network structures are considered,including a nearest-neighbor coupled network,a Newman-Watts small world network,an Erd¨os-Renyi random network and a Barabasi-Albert(BA)scale free network.The results show that the FRP is longest in the BA network,because the BA network is characterized by the most heterogeneous structure among these four types of networks.These findings are not affected by the average node degree of the SCN network or the value of relaxation rate of the SCN neuronal oscillators.Our findings contribute to the understanding of how the network structure of the SCN neurons influences the FRP. 展开更多
关键词 circadian rhythm light sensitivity heterogeneous network free running period
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Pile Running in Layered Soils
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作者 ZHAO Huan WANG Le +3 位作者 SUN Li-qiang TIAN Ying-hui Oliver REUL CHEN Quan-zhen 《China Ocean Engineering》 SCIE EI CSCD 2023年第5期829-841,共13页
This paper presents a case study on incidents of offshore pile running in layered soils.The study provides a detailed description of the seabed soil data,pile driving records,and field surveillance video observations.... This paper presents a case study on incidents of offshore pile running in layered soils.The study provides a detailed description of the seabed soil data,pile driving records,and field surveillance video observations.Three-dimensional large deformation finite element(LDFE)analyses were conducted to retrospectively analyze the incidents,considering the remoulding of seabed soil and degradation of the pile-soil interface in the LDFE modeling.By comparing the field observations with the LDFE analysis,the mechanism of pile running was discussed,with a focus on investigating the pile penetration resistance in each layer.The study revealed that pile running in layered soils primarily resulted from a significant reduction in pile base resistance when transitioning from a strong layer to an adjacent weak layer.To further investigate the pile running mechanism in layered soils,a parametric study on the strength variation of adjacent soil layers and its influence on pile base resistance was conducted.Lastly,a simplified prediction model of pile base resistance,suitable for assessing the risk of pile running in layered soils,was proposed. 展开更多
关键词 pile running coupled Eulerian−Lagrangian method layered soil penetration resistance pile−soil interaction
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基于多维Copula函数的澜沧江-湄公河流域气象干旱特征分析 被引量:3
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作者 李琼芳 方凯悦 +4 位作者 韩幸烨 邹振华 陈启慧 尹瑞琪 林雍权 《水资源保护》 EI CSCD 北大核心 2024年第1期52-59,共8页
为全面揭示变化环境下澜湄流域多维气象干旱特征,采用标准化降水蒸散指数SPEI表征流域气象干旱,基于游程理论分别提取澜沧江段和湄公河段上、中、下游流域1901—1960年和1961—2021年两个时段的干旱事件,利用Copula函数分别构建两个时... 为全面揭示变化环境下澜湄流域多维气象干旱特征,采用标准化降水蒸散指数SPEI表征流域气象干旱,基于游程理论分别提取澜沧江段和湄公河段上、中、下游流域1901—1960年和1961—2021年两个时段的干旱事件,利用Copula函数分别构建两个时段不同子流域二维和三维干旱特征变量联合分布,计算不同干旱特征变量组合条件下的干旱联合发生概率,对比分析不同子流域多维气象干旱特征的时空变化。结果表明:时间上,1961—2021年各子流域平均干旱程度均较1901—1960年更严峻,尤其是极端干旱事件(单变量累积频率为25%、50%)的多维干旱联合发生概率增幅最大;空间上,1961—2021年,随着干旱历时、烈度和烈度峰值的增加,“或”情况下多维干旱联合发生概率最高值区自北向南转移,“且”情况下多维干旱联合发生概率最高值区自南向北转移。 展开更多
关键词 气象干旱 游程理论 联合发生概率 COPULA函数 澜沧江-湄公河流域
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基于RUN-XGBoost算法的土石坝渗流预测模型 被引量:1
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作者 马春辉 侯媛媛 +2 位作者 杨杰 袁帅 徐笑颜 《水利水电科技进展》 CSCD 北大核心 2024年第2期72-78,共7页
针对传统土石坝渗流预测模型存在局部最优、抗干扰性差和预测精度低等问题,通过RUN算法优化XGBoost算法得到RUN-XGBoost算法,构建了RUN-XGBoost模型以获得更优的土石坝渗流预测结果。该模型在种群初始化时采用RUN算法对XGBoost算法的3... 针对传统土石坝渗流预测模型存在局部最优、抗干扰性差和预测精度低等问题,通过RUN算法优化XGBoost算法得到RUN-XGBoost算法,构建了RUN-XGBoost模型以获得更优的土石坝渗流预测结果。该模型在种群初始化时采用RUN算法对XGBoost算法的3个主要参数进行改进,使预测结果有较高的有效性;通过自动寻找最优参数增进算法的整体收敛速度和预测精度,同时引入随机解,使算法能够排除局部最小值并继续搜索,从而获得全局最优结果。工程实例验证结果表明,RUN-XGBoost模型具有简洁、高效、预测精度高、鲁棒性强等优点。 展开更多
关键词 土石坝 渗流监测 RUN-XGBoost算法 预测模型
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基础教育集团化办学的“内卷化”困境及其纾解 被引量:2
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作者 吴支奎 黄丽丽 《当代教育论坛》 北大核心 2024年第3期43-49,共7页
集团化办学是我国基础教育领域的创新之举,其在扩大优质教育资源配置、带动薄弱学校协同发展、推进教育均衡发展等方面发挥了重要作用,但也出现了办学规模扩大、教育质量下滑或无效发展等问题。研究借助“内卷化”理论话语,透析当前基... 集团化办学是我国基础教育领域的创新之举,其在扩大优质教育资源配置、带动薄弱学校协同发展、推进教育均衡发展等方面发挥了重要作用,但也出现了办学规模扩大、教育质量下滑或无效发展等问题。研究借助“内卷化”理论话语,透析当前基础教育集团化办学存在“科层制”权力运行模式衍生权力结构内卷化,错综的关系网络环境导致人际关系复杂化,“依赖性”的发展思维与路径致使发展动力外在化,过度的市场迎合取向造成优质资源供需失衡化等“内卷化”困境。纾解基础教育集团化办学“内卷化”困境可夯实学校共同体建设,建构多元主体权力结构;加强监管与法治建设,破除关系网络顽疾;激发薄弱学校内在发展动力,助力优质资源再创生;调适集团化办学规模,回归学校教育初心。 展开更多
关键词 基础教育 集团化办学 “内卷化” 均衡发展
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髌股关节痛业余跑者的下肢肌力特征分析 被引量:1
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作者 戴剑松 陈钢锐 +1 位作者 王沛珣 顾忠科 《中国康复医学杂志》 CAS CSCD 北大核心 2024年第3期369-374,共6页
目的:研究髌股关节痛(patellofemoral pain,PFP)业余跑者的下肢肌力特征。方法:招募PFP业余跑者30例(男性20例,女性10例)作为膝痛组,并匹配30例无损伤的业余跑者作为非膝痛组,采集所有受试者的髋关节外展力量、股四头肌力量、腘绳肌力量... 目的:研究髌股关节痛(patellofemoral pain,PFP)业余跑者的下肢肌力特征。方法:招募PFP业余跑者30例(男性20例,女性10例)作为膝痛组,并匹配30例无损伤的业余跑者作为非膝痛组,采集所有受试者的髋关节外展力量、股四头肌力量、腘绳肌力量,并计算腘绳肌/股四头肌比值、双侧肢体力量对称指数等。采用独立样本t检验对不同组别的各项指标进行统计学检测。结果:男性PFP业余跑者的髋关节外展力量及对称指数、股四头肌力量及对称指数显著小于非膝痛组,腘绳肌/股四头肌比值显著大于非膝痛组;女性PFP业余跑者的髋关节外展力量及对称指数显著小于非膝痛组。结论:PFP业余跑者与非膝痛跑者表现出不同的下肢肌力特征,其男性与女性PFP业余跑者下肢力量特点表现并不一致,PFP康复训练中应考虑功能性及性别差异。 展开更多
关键词 髌股关节痛 跑步 下肢力量 对称指数 腘绳肌/股四头肌比值
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走行轮失效对单轨车辆安全性及平稳性的影响
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作者 文孝霞 李竞一 +1 位作者 杜子学 杨震 《机械设计与制造》 北大核心 2024年第10期352-358,共7页
单轨车辆走行轮为充气橡胶轮胎,容易因磨耗、穿刺而失气、漏气,导致走行轮失效。走行轮失效对车辆运行安全性及平稳性有重大影响,本文在单轨车辆走行轮动力学模型上进行走行轮失效处理,研究走行轮失效对单轨车辆运行安全性和平稳性的影... 单轨车辆走行轮为充气橡胶轮胎,容易因磨耗、穿刺而失气、漏气,导致走行轮失效。走行轮失效对车辆运行安全性及平稳性有重大影响,本文在单轨车辆走行轮动力学模型上进行走行轮失效处理,研究走行轮失效对单轨车辆运行安全性和平稳性的影响。研究结果表明:空载和满载工况任一走行轮失效以(5~30)km/h速度行驶在半径100m左转弯道时,轮轨力均大于正常行驶工况,运行安全性差;同侧走行轮失效时对运行安全性的规律相同,左侧走形轮失效工况最恶劣;横向平稳性等级合格,垂向平稳性部分合格,建议以10km/h的速度行驶到维修中心。 展开更多
关键词 单轴转向架 单轨车辆 走行轮失效 运行安全性 运行平稳性 影响分析
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流水句形成的顺序象似性句法机制 被引量:1
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作者 翁义明 肖清敏 《信阳师范学院学报(哲学社会科学版)》 2024年第1期121-126,共6页
文章基于语言顺序象似性的基本原则,从语言类型学的视角通过实例语料的分析,发现汉语句子中的定语、状语等修饰语在遵循顺序象似性原则的情形下,可自由不加标记地转换成并列小句,从修饰语位置提升为与主句并列的述谓结构,这是汉语流水... 文章基于语言顺序象似性的基本原则,从语言类型学的视角通过实例语料的分析,发现汉语句子中的定语、状语等修饰语在遵循顺序象似性原则的情形下,可自由不加标记地转换成并列小句,从修饰语位置提升为与主句并列的述谓结构,这是汉语流水句形成的主要内在机制与形式手段。 展开更多
关键词 流水句 顺序象似性 句法成分 述谓功能
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基于管柱动力学的特深井通井组合刚度评价方法与应用 被引量:1
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作者 祝效华 李文哲 +5 位作者 李柯 陈力力 孟鐾桥 沈欣宇 罗伟 贺明敏 《钻采工艺》 CAS 北大核心 2024年第2期51-58,共8页
我国特深井钻井正处于快速发展阶段,受井眼尺寸大和深度深的影响,钻井过程中极易出现微井斜、扩径缩径和井壁台阶等,导致套管下入困难,因此通井钻具组合评价尤为重要。目前,现场使用的评价方法常忽略了管柱下入过程中与井壁的碰撞和变形... 我国特深井钻井正处于快速发展阶段,受井眼尺寸大和深度深的影响,钻井过程中极易出现微井斜、扩径缩径和井壁台阶等,导致套管下入困难,因此通井钻具组合评价尤为重要。目前,现场使用的评价方法常忽略了管柱下入过程中与井壁的碰撞和变形,导致通井效果时好时坏。为了辅助现场施工,文章基于全井管柱动力学模型和HHT-α数值计算方法提出了一种能够模拟管柱下入的动态过程的通井钻具组合的评价方法,该方法考虑了实测井眼轨迹、井眼扩大率和下入阻力等要素。通过某特深井三开下套管前的钻具组合进行实例计算分析,表明井眼扩大率和套管串下入阻力对通井能力和套管下入影响较大,当井眼扩大率较小且套管串下入阻力较大时,需要使用刚度较大的多扶正器通井钻具组合。本方法可以实现实测井况条件下比较精准的刚度对比模拟,也成功指导了案例井?486 mm套管的安全下入。 展开更多
关键词 特深井 通井钻具组合 管柱动力学模型 刚度比 井眼扩大率 下入阻力
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基于GBS测序的湘东黑山羊的亲缘关系及近交系数 被引量:1
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作者 刘海林 江为民 +4 位作者 段洪峰 李昊帮 罗璋 李安定 龚龑 《湖南农业大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第2期78-85,共8页
利用基因分型测序(GBS)对60只湘东黑山羊(9只公羊、51只母羊)进行基因组测序,获得湘东黑山羊染色体上的SNP数据和连续纯合子片段(ROH)数据。通过SNP数据进行基于G矩阵的基因组亲缘关系分析和NJ聚类分析,构建湘东黑山羊的群体家系结构,... 利用基因分型测序(GBS)对60只湘东黑山羊(9只公羊、51只母羊)进行基因组测序,获得湘东黑山羊染色体上的SNP数据和连续纯合子片段(ROH)数据。通过SNP数据进行基于G矩阵的基因组亲缘关系分析和NJ聚类分析,构建湘东黑山羊的群体家系结构,并通过ROH数据得到群体平均近交系数。结果表明,60只湘东黑山羊的平均测序深度为9.15X,与参考基因组比对率平均为99.59%;在SNP检测过程中,3只母羊不符合基因型数据质控标准,将其过滤后获得其他57只黑山羊29条染色体上153046个SNPs位点和1937个ROH片段;构建的湘东黑山羊8个家系,其中9只公羊和6只母羊被分为7个家系,另42只母羊被单独分类;基于ROH片段分析的湘东黑山羊群体中每个个体的近交系数均值为0.047,说明湘东黑山羊公羊在繁育过程中有较大的利用空间。 展开更多
关键词 湘东黑山羊 基因分型测序 单核苷酸多态性 连续纯合子片段 近交系数 亲缘关系
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下陡上缓混合式海堤上不规则波爬高研究
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作者 苗青 张从联 江洧 《水电能源科学》 北大核心 2024年第8期192-196,共5页
波浪爬高是影响海堤堤顶高程的一个重要因素,直接影响工程投资。下部为陡墙、上部为斜坡、中间带平台的海堤为我国沿海常见的一种海堤断面型式,为研究此种海堤断面型式上不规则波爬高规律,通过物理模型试验观测得到不同试验条件下波浪爬... 波浪爬高是影响海堤堤顶高程的一个重要因素,直接影响工程投资。下部为陡墙、上部为斜坡、中间带平台的海堤为我国沿海常见的一种海堤断面型式,为研究此种海堤断面型式上不规则波爬高规律,通过物理模型试验观测得到不同试验条件下波浪爬高,并根据海堤下部陡墙坡度、上部斜坡坡度、平台宽度与平台高度、波浪要素对波浪爬高的影响分析,拟合了不规则波爬高计算公式。结果表明,陡墙坡度为0的海堤的波浪爬高值比0.5小;当波陡在0.03~0.05之间时,随着海堤上部坡度变缓,大部分波浪爬高逐渐减小;波浪爬高随着平台宽度的增加而减小;波浪爬高随着海堤平台位置的降低而增大;波浪爬高随着波陡的增加呈现先增大后减小的趋势;拟合公式可反映下部为陡墙、中间为平台、上部为斜坡的混合式海堤断面上波浪爬高规律。 展开更多
关键词 堤防 不规则波 爬高 混合式海堤 试验
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