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The influence of resistance exercise training prescription variables on skeletal muscle mass,strength,and physical function in healthy adults:An umbrella review 被引量:1
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作者 Jonathan C.Mcleod Brad S.Currier +1 位作者 Caroline V.Lowisz Stuart M.Phillips 《Journal of Sport and Health Science》 SCIE CSCD 2024年第1期47-60,共14页
Purpose:The aim of this umbrella review was to determine the impact of resistance training(RT)and individual RT prescription variables on muscle mass,strength,and physical function in healthy adults.Methods:Following ... Purpose:The aim of this umbrella review was to determine the impact of resistance training(RT)and individual RT prescription variables on muscle mass,strength,and physical function in healthy adults.Methods:Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)guidelines,we systematically searched and screened eligible systematic reviews reporting the effects of differing RT prescription variables on muscle mass(or its proxies),strength,and/or physical function in healthy adults aged>18 years.Results:We identified 44 systematic reviews that met our inclusion criteria.The methodological quality of these reviews was assessed using A Measurement Tool to Assess Systematic Reviews;standardized effectiveness statements were generated.We found that RT was consistently a potent stimulus for increasing skeletal muscle mass(4/4 reviews provide some or sufficient evidence),strength(4/6 reviews provided some or sufficient evidence),and physical function(1/1 review provided some evidence).RT load(6/8 reviews provided some or sufficient evidence),weekly frequency(2/4 reviews provided some or sufficient evidence),volume(3/7 reviews provided some or sufficient evidence),and exercise order(1/1 review provided some evidence)impacted RT-induced increases in muscular strength.We discovered that 2/3 reviews provided some or sufficient evidence that RT volume and contraction velocity influenced skeletal muscle mass,while 4/7 reviews provided insufficient evidence in favor of RT load impacting skeletal muscle mass.There was insufficient evidence to conclude that time of day,periodization,inter-set rest,set configuration,set end point,contraction velocity/time under tension,or exercise order(only pertaining to hypertrophy)influenced skeletal muscle adaptations.A paucity of data limited insights into the impact of RT prescription variables on physical function.Conclusion:Overall,RT increased muscle mass,strength,and physical function compared to no exercise.RT intensity(load)and weekly frequency impacted RT-induced increases in muscular strength but not muscle hypertrophy.RT volume(number of sets)influenced muscular strength and hypertrophy. 展开更多
关键词 HYPERTROPHY Resistance training Resistance training prescription variables STRENGTH umbrella review
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Risk factors for running-related injuries:An umbrella systematic review
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作者 Clara Knierim Correia Jean Marlon Machado +3 位作者 Fabio Hech Dominski Marcelo Peduzzi de Castro Heiliane de Brito Fontana Caroline Ruschel 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第6期793-804,共12页
Purpose:This umbrella systematic review(SR) of SRs and meta-analysis seeks to comprehensively synthesize existing literature to identify and consolidate the diverse range of risk factors contributing to running-relate... Purpose:This umbrella systematic review(SR) of SRs and meta-analysis seeks to comprehensively synthesize existing literature to identify and consolidate the diverse range of risk factors contributing to running-related injuries(RRIs).Methods:Systematic searches were conducted on June 28,2023,across Web of Science,SPORTDiscus,Scopus,PubMed,and Cochrane Library.We included SRs,whether accompanied by meta-analyses or not,that focused on investigating risk factors for RRIs within observational studies.The methodological quality of the SRs was evaluated using the Assessing the Methodological Quality of Systematic Reviews Ⅱ.To assess the extent of overlap across reviews,the corrected covered area metric was calculated.Results:From 1509 records retrieved,13 SRs were included.The degree of overlap between SRs was low(4%),and quality varied from critically low(n=8) to low(n=5).Two hundred seven outcomes assessed in 148 primary studies were identified as being associated with the occurrence of RRIs.The effect sizes of the associations for which risk measures were reported(n=131) were classified as large(n=30,23%),medium(n=38,29%),small(n=48,37%) or no effect(n=15,11%).Running/training characteristics,health and lifestyle factors,along with morphological and biomechanical aspects,exhibit large effect sizes in increasing the risk for RRIs.Conclusion:Drawing from the outcomes of the low-quality SRs and associations with large effect sizes,our findings indicate that running/training characteristics and health and lifestyle factors,as well as morphological and biomechanical aspects,are all implicated in elevating the risk of RRIs,emphasizing the multifactorial basis of injury incidence in running.Given the low quality and heterogeneity of SR,individual findings warrant cautious interpretation. 展开更多
关键词 umbrella review RUNNERS Injury Risk factor
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Assessing the effectiveness of internetbased interventions for mental health outcomes:an umbrella review
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作者 Mi Zhang Chuan Fan +6 位作者 Lijun Ma Huixue Wang Zhenyue Zu Linxi Yang Fenglan Chen Wenzhuo Wei Xiaoming Li 《General Psychiatry》 CSCD 2024年第4期452-462,共11页
Internet-based interventions(IBIs)for behavioural health have been prevalent for over two decades,and a growing proportion of individuals with mental health concerns prefer these emerging digital alternatives.However,... Internet-based interventions(IBIs)for behavioural health have been prevalent for over two decades,and a growing proportion of individuals with mental health concerns prefer these emerging digital alternatives.However,the effectiveness and acceptability of IBIs for various mental health disorders continue to be subject to scholarly debate.We performed an umbrella review of meta-analyses(MAs),conducting literature searches in PubMed,Web of Science,Embase,Cochrane and Ovid Medline from their inception to 17 January 2023.A total of 87MAs,reporting on 1683 randomised controlled trials and 295589 patients,were included.The results indicated that IBIs had a moderate effect on anxiety disorder(standardised mean difference(SMD)=0.53,95%CI 0.44 to 0.62)and post-traumatic stress disorder(PTSD)(SMD=0.63,95%CI 0.38 to 0.89).In contrast,the efficacy on depression(SMD=0.45,95%CI 0.39 to 0.52),addiction(SMD=0.23,95%CI 0.16 to 0.31),suicidal ideation(SMD=0.23,95%CI 0.16 to 0.30),stress(SMD=0.41,95%CI 0.33 to 0.48)and obsessive-compulsive disorder(SMD=0.47,95%CI 0.22 to 0.73)was relatively small.However,no significant effects were observed for personality disorders(SMD=0.07,95%CI-0.13 to 0.26).Our findings suggest a significant association between IBIs and improved mental health outcomes,with particular effectiveness noted in treating anxiety disorders and PTSD.However,it is noteworthy that the effectiveness of IBIs was impacted by high dropout rates during treatment.Furthermore,our results indicated that guided IBIs proved to be more effective than unguided ones,playing a positive role in reducing dropout rates and enhancing patient adherence rates. 展开更多
关键词 INTERNET umbrella CONDUCTING
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Comprehensive evaluation of the transformer oil-paper insulation state based on RF-combination weighting and an improved TOPSIS method 被引量:8
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作者 Fugen Song Shichao Tong 《Global Energy Interconnection》 EI CAS CSCD 2022年第6期654-665,共12页
The accurate identification of the oil-paper insulation state of a transformer is crucial for most maintenance strategies.This paper presents a multi-feature comprehensive evaluation model based on combination weighti... The accurate identification of the oil-paper insulation state of a transformer is crucial for most maintenance strategies.This paper presents a multi-feature comprehensive evaluation model based on combination weighting and an improved technique for order of preference by similarity to ideal solution(TOPSIS)method to perform an objective and scientific evaluation of the transformer oil-paper insulation state.Firstly,multiple aging features are extracted from the recovery voltage polarization spectrum and the extended Debye equivalent circuit owing to the limitations of using a single feature for evaluation.A standard evaluation index system is then established by using the collected time-domain dielectric spectrum data.Secondly,this study implements the per-unit value concept to integrate the dimension of the index matrix and calculates the objective weight by using the random forest algorithm.Furthermore,it combines the weighting model to overcome the drawbacks of the single weighting method by using the indicators and considering the subjective experience of experts and the random forest algorithm.Lastly,the enhanced TOPSIS approach is used to determine the insulation quality of an oil-paper transformer.A verification example demonstrates that the evaluation model developed in this study can efficiently and accurately diagnose the insulation status of transformers.Essentially,this study presents a novel approach for the assessment of transformer oil-paper insulation. 展开更多
关键词 Combined weight method Random forest algorithm Insulation aging assessment oil-paper insulation Time-domain eigenvalue
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Chaotic Characteristic of Time Series of Partial Discharge in Oil-Paper Insulation
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作者 罗勇芬 纪海英 +1 位作者 黄平 李彦明 《Plasma Science and Technology》 SCIE EI CAS CSCD 2011年第6期740-746,共7页
The chaotic characteristics of time series of five partial discharge (PD) patterns in oil-paper insulation are studied. The results verify obvious chaotic characteristic of the time series of discharge signals and t... The chaotic characteristics of time series of five partial discharge (PD) patterns in oil-paper insulation are studied. The results verify obvious chaotic characteristic of the time series of discharge signals and the fact that PD is a chaotic process. These time series have distinctive features, and the chaotic attractors obtained from time series differed greatly from each other by shapes in the phase space, so they could be used to qualitatively identify the PD patterns. The phase space parameters are selected, then the chaotic characteristic quantities can be extracted. These quantities could quantificationally characterize the PD patterns. The effects on pattern recognition of PRPD and CAPD are compared by using the neural network of radial basis function. The results show that both of the two recognition methods work well and have their respective advantages. Then, both the statistical operators under PRPD mode and the chaotic characteristic quantities under CAPD mode are selected comprehensively as the input vectors of neural network, and the PD pattern recognition accuracy is thereby greatly improved. 展开更多
关键词 oil-paper insulation partial discharge time series CHAOS pattern recognition
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The Research of Connection between Degree of Polymerization and Frequency Domain Dielectric Spectroscopy Characteristics during Oil-Paper Insulation Aging
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作者 Danyu Jiang Guangning Wu +1 位作者 Xian Yang Qingkai Hao 《Energy and Power Engineering》 2017年第4期667-674,共8页
In order to study the linkage effects between degree of polymerization and frequency domain dielectric spectroscopy characteristics of oil-paper insulation, the frequency domain dielectric response test platform of oi... In order to study the linkage effects between degree of polymerization and frequency domain dielectric spectroscopy characteristics of oil-paper insulation, the frequency domain dielectric response test platform of oil-paper insulation is set up. Complex permittivity of oil-paper insulation respectively composed by new or aged oil and insulation paper with different DP are tested, and complex permittivity of oil-paper insulation respectively composed by insulation respectively composed by new oil and insulation paper with different DP and low or high moisture content are tested. The test results are analyzed, and the analysis results show that the degree of polymerization of insulation paper has an influence on complex permittivity of oil-paper insulation though influencing the distribution of moisture and acids between oil and paper. 展开更多
关键词 DEGREE of POLYMERIZATION oil-paper INSULATION Frequency DOMAIN Dielectric Spectroscopy MOISTURE
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Impact of citrus fruit and hesperidin intake on multiple health outcomes:An umbrella review
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作者 Yu-Sen Cheng Yong Zhou 《Journal of Nutritional Oncology》 2023年第1期16-24,共9页
Citrus fruits are rich sources of several biologically active flavonoids such as hesperidin,naringin,and polymethoxylated flavones.We evaluated the evidence of associations between citrus fruit or hesperidin intake an... Citrus fruits are rich sources of several biologically active flavonoids such as hesperidin,naringin,and polymethoxylated flavones.We evaluated the evidence of associations between citrus fruit or hesperidin intake and multiple health outcomes.An umbrella review was conducted for studies performed in humans.Overall,246 articles were initially identified by searching in 4 databases.Twenty-two meta-analyses and systematic reviews with 28 health outcomes met the inclusion criteria.Citrus fruit intake had beneficial effects on all-cause mortality(relative risk[RR].0.90;95%confidence interval[95%CI],0.86 to 0.94),cardiovascular diseases(RR,0.78;95%CI,0.66 to 0.92),coronary heart disease(RR,0.91;95%CI,0.86 to 0.96),stroke(RR,0.74;95%CI,0.65 to 0.84),type 2 diabetes mellitus(RR,0.85;95%CI,0.78 to 0.92),and several cancers.Dose-response analyses indicated that each 100-g/d increase in citrus fruit intake could reduce the risks of all-cause mortality by 6%(RR,0.94;95%CI,0.88 to 1.00),stroke by 22%(RR,0.78;95%CI,0.69 to 0.90),and cardia gastric cancer by 40%(RR,0.60;95%CI,0.44 to 0.83).Citrus fruit intake also had beneficial effects on the lipid profile and body weight control(weighted mean difference,−1.28;95%CI,−1.82 to−0.74).Grapefruits could reduce the systolic blood pressure(weighted mean difference,−2.43,95%CI,−4.77 to−0.09).Hesperidin supplementation significantly improved inflammation.Citrus fruit intake was generally safe and beneficial for multiple health outcomes in humans.However,grapefruit and pomelo juice may affect the bioavailability of various medications,so care should be exercised before increasing the intake of these fruits or their juices. 展开更多
关键词 Citrus fruit HESPERIDIN HEALTH umbrella review META-ANALYSIS Systematic review
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基于专利布局和TRIZ的防滴水折叠伞设计研究 被引量:1
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作者 鲁玉军 赵犟军 崔志军 《设计》 2024年第1期12-15,共4页
为解决折叠伞在使用后存在的雨水处理不便等问题,采用TRIZ创新方法设计了一种新型折叠伞。并对设计方案进行专利布局保护。首先,选取关键词和IPC分类号构建检索式,利用专利搜索引擎确定全球折叠伞专利并分析技术构成;然后,运用TRIZ创新... 为解决折叠伞在使用后存在的雨水处理不便等问题,采用TRIZ创新方法设计了一种新型折叠伞。并对设计方案进行专利布局保护。首先,选取关键词和IPC分类号构建检索式,利用专利搜索引擎确定全球折叠伞专利并分析技术构成;然后,运用TRIZ创新方法对折叠伞进行创新设计,得到防滴水折叠伞核心专利;最后,结合专利布局的组合类型,围绕核心专利对折叠伞进行降落伞型的组合式专利布局。结果表明,所设计的防滴水折叠伞可实现雨水的便捷处理且便于收纳,并通过专利布局保护对核心专利进行了有效保护。研究结果为制伞企业构建完善创新设计和专利防御体系提供了一种有效方法。 展开更多
关键词 创新设计 专利布局 TRIZ 折叠伞 防滴水 矛盾分析
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多段移动床干馏炉集气结构的优化研究
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作者 吴鹏 王森 +2 位作者 王兴坤 戴航 苗文华 《煤化工》 CAS 2024年第3期11-15,共5页
为考察移动床干馏炉内部集气结构对串气率的影响,以陕北低阶碎煤为试验对象,搭建移动床冷态试验装置,在不同进气流量下测定各层气量的流量分配比例,研究在不同位置增设集气结构对气体分布的影响。结果表明:气体经布气伞进入移动床后,有... 为考察移动床干馏炉内部集气结构对串气率的影响,以陕北低阶碎煤为试验对象,搭建移动床冷态试验装置,在不同进气流量下测定各层气量的流量分配比例,研究在不同位置增设集气结构对气体分布的影响。结果表明:气体经布气伞进入移动床后,有10%的气量无法通过集气主伞流出,而从卸料口泄漏导致串气。在布气伞下部0.6 m和1.2 m处、集气主伞上部0.6 m处分别增设一层集气伞,均可以降低串气比例。同时在上部与中部或中部与下部增加两层集气伞时,可以使串气率降低为0。当中部集气伞与主伞内的压差由0 Pa增加至80 Pa时,串气率由2.80%升高至5.22%,设计炉内结构时应考虑降低沿程阻力损失或者加设集气通道。 展开更多
关键词 移动床 干馏炉 低阶碎煤 热解 集气伞
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伞状浮动阀压电泵的设计与试验
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作者 严天祥 宋检祥 +2 位作者 倪辉 李先瑄 陈虎城 《中国机械工程》 EI CAS CSCD 北大核心 2024年第11期1971-1976,1985,共7页
针对球阀压电泵输出性能不佳和伞阀压电泵易于疲劳失效的问题,基于球阀的浮动式工作原理和伞阀的结构特征,设计了一种性能优良且不易疲劳失效的伞状浮动阀压电泵。制作了伞状浮动阀压电泵与球阀压电泵的样机,测试分析了两种泵的输出性... 针对球阀压电泵输出性能不佳和伞阀压电泵易于疲劳失效的问题,基于球阀的浮动式工作原理和伞阀的结构特征,设计了一种性能优良且不易疲劳失效的伞状浮动阀压电泵。制作了伞状浮动阀压电泵与球阀压电泵的样机,测试分析了两种泵的输出性能。研究结果表明,当驱动电压为300 V(峰峰值)时,伞状浮动阀压电泵的最大流量和最高压力差均优于球阀压电泵。对伞状浮动阀压电泵进行了双入口结构改进,试验对比了双入口与单入口伞状浮动阀压电泵的输出性能。试验结果表明,在驱动电压300 V_(pp)下,双入口伞状浮动阀压电泵的最大流量和最大压力差分别为121.66 g/min和7.71 kPa,较单入口伞状浮动阀压电泵分别提高17.23%和32.93%。 展开更多
关键词 球阀 伞状浮动阀 压电泵 流量 压力差
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基于自适应模型预测的物伞系统速度跟踪控制
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作者 陈立锋 石添文 +1 位作者 黄良沛 刘文雯 《兵器装备工程学报》 CAS CSCD 北大核心 2024年第6期175-180,共6页
针对空投易碎易爆物品无速度跟踪及速度波动大的问题,提出自适应模型预测控制(model predictive control,MPC)方法对物伞系统速度进行控制跟踪。以线性离散化物伞系统动力学模型为基础,通过迭代法构建速度跟踪预测模型,依据实际需求设... 针对空投易碎易爆物品无速度跟踪及速度波动大的问题,提出自适应模型预测控制(model predictive control,MPC)方法对物伞系统速度进行控制跟踪。以线性离散化物伞系统动力学模型为基础,通过迭代法构建速度跟踪预测模型,依据实际需求设计目标函数及约束条件,在自适应MPC控制器内进行优化求解;引入卡尔曼滤波作为状态估计器,让系统具备对自身状态量变化的感知,提供估计状态量给控制器,实现系统整体反馈校正。开展无风条件和有风条件下自适应MPC控制的物伞系统速度跟踪性能研究,结果表明,此控制方法能够实现对期望速度的良好跟踪;在随机扰动下进行物伞系统速度跟踪控制鲁棒性研究,对比分析了自适应MPC方法和PID控制方法的速度跟踪性能,结果表明,自适应MPC控制的物伞系统速度振荡小于PID控制,其具有较强的抗非线性扰动能力,为实现物伞系统速度控制提供了新方法。 展开更多
关键词 物伞系统 自适应模型预测控制 卡尔曼滤波器 速度跟踪控制 PID
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秦陵铜立车舆内铜伞的构成方式及形态特征
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作者 宗椿理 《湖南工业大学学报(社会科学版)》 2024年第4期110-118,共9页
秦陵铜立车舆内铜伞由伞盖、盖杠及盖座三部分组构而成,其伞形车盖、铜箍扣接的“盖杠”“盖座”与“樘柱”的构成方式与锁闭的结构设计仿照实用舆马中铜伞的铸造细节,从礼用之器的实用性摹写、结构设计的创新性改变、材料工艺的多元性... 秦陵铜立车舆内铜伞由伞盖、盖杠及盖座三部分组构而成,其伞形车盖、铜箍扣接的“盖杠”“盖座”与“樘柱”的构成方式与锁闭的结构设计仿照实用舆马中铜伞的铸造细节,从礼用之器的实用性摹写、结构设计的创新性改变、材料工艺的多元性融合、装饰设计的审美性表达等角度体现出秦代造物工匠在“造物”与“造美”中的设计智慧诠释。考据先秦以来车舆马具的造物遗存,秦陵铜立车舆内铜伞为研究者提供了一个“史以物凭”的视角,使其在对文本史料解读的同时,能够结合实物佐证考究先秦车制体系的演进历程;其为研究相关的青铜铸造工艺及装饰设计的审美表达等提供了可资参考的典型案例。 展开更多
关键词 秦陵铜立车 铜伞 构成方式 形态特征
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可调弯鞘在回收困难的伞形下腔静脉滤器取出术中的应用
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作者 蒋盘强 顾叶秋 +1 位作者 高敏亚 王宏飞 《血管与腔内血管外科杂志》 2024年第7期797-800,821,共5页
目的探讨可调弯鞘在回收困难的伞形下腔静脉滤器取出术中的应用价值。方法收集2021年7月至2023年2月于南京中医药大学附属无锡医院就诊的24例滤器回收困难患者临床资料,均采用可调弯鞘进行滤器回收,分析所有患者的手术成功率,观察下腔... 目的探讨可调弯鞘在回收困难的伞形下腔静脉滤器取出术中的应用价值。方法收集2021年7月至2023年2月于南京中医药大学附属无锡医院就诊的24例滤器回收困难患者临床资料,均采用可调弯鞘进行滤器回收,分析所有患者的手术成功率,观察下腔静脉血流通畅情况、管壁情况、造影剂外溢或滞留情况、滤器情况、相关并发症发生情况。结果23例患者手术成功,1例因患有阿尔茨海默病,术中不能配合而放弃手术。回收滤器均结构完整、无折断,无变形,滤器取出后行下腔静脉造影均未发现造影剂滞留或外渗。手术时间25~120 min,平均58 min,未明显增加手术时间及费用,无相关并发症发生。结论应用可调弯鞘可以显著提高回收钩贴壁的下腔静脉滤器回收成功率,安全、有效,具有一定的临床应用价值。 展开更多
关键词 下肢深静脉血栓形成 下腔静脉滤器 可调弯鞘 伞形滤器 回收钩贴壁
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“二元社会结构”视域下农业特色产业发展路径的分析——以云南花卉产业的发展为例
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作者 张继焦 陈亭佳沁 《大理大学学报》 2024年第11期25-33,共9页
发展特色农业是我国农业结构战略调整的要求,是提高我国农业国际竞争力的要求,是增加农民收入的迫切需要。云南花卉产业就是发展农业特色产业的一个成功实例,从1983年斗南收获的第一枝剑兰到现在成为全球三大花卉主产区之一,云南花卉产... 发展特色农业是我国农业结构战略调整的要求,是提高我国农业国际竞争力的要求,是增加农民收入的迫切需要。云南花卉产业就是发展农业特色产业的一个成功实例,从1983年斗南收获的第一枝剑兰到现在成为全球三大花卉主产区之一,云南花卉产业的发展一直是相关学者热烈讨论的内容。利用“二元社会结构”理论,以云南花卉的产业发展为对象,分析政府力量代表的“伞式社会”和民间力量代表的“蜂窝式社会”在产业发展的各个阶段所发挥的作用。认为在花卉产业形成之初,民间自发性的探索力量以“蜂窝式”扩张,为产业发展奠定了规模基础;随着产业发展,政府力量入场,自上而下提供资源扶持产业发展,激发了产业发展潜力,与民间力量相互补充;进入新发展阶段,政府的“伞式”支持更加多层面、多方位、多领域,与民间“网络式”开拓促进产业升级完善,共同推动云南花卉产业可持续发展。 展开更多
关键词 “二元社会结构” “伞式社会” “蜂窝式社会” 云南花卉产业 农业特色产业发展
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低频小振动能量收集的伞型摩擦纳米发电机 被引量:2
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作者 刘安国 苏玉香 +2 位作者 罗健锋 赵柯洋 赵西增 《中国电机工程学报》 EI CSCD 北大核心 2024年第10期4103-4111,I0030,共10页
针对摩擦纳米发电机功率密度低、触发难、耐久度差的问题,该文设计一种伞型摩擦纳米发电机(umbrella-shape triboelectric nanogenerator,U-TENG)用于收集低频小振动能量。U-TENG以纸基作为连接机构,使上下伞叶在振动环境中进行有序开合... 针对摩擦纳米发电机功率密度低、触发难、耐久度差的问题,该文设计一种伞型摩擦纳米发电机(umbrella-shape triboelectric nanogenerator,U-TENG)用于收集低频小振动能量。U-TENG以纸基作为连接机构,使上下伞叶在振动环境中进行有序开合,可以有效增加摩擦层数量、增大接触面积、改善接触面的贴合效果。另外,在摩擦电单元的设计上,通过叠放氟橡胶提高导电层上的感应电荷量,以优化电能输出性能。实验结果表明:当两个摩擦电单元并联运行时,UTENG的最大短路电流和开路电压分别能够达到125.9μA和804 V;在低频小幅振动下其瞬时功率密度最高达到509.3 W/m^(3);U-TENG可以收集环境中不同形式的振动能,以收集脉冲式振动的能力尤为突出,最多可驱动960个LED灯。该方法可为环境中低频振动能的高效捕获提供思路。 展开更多
关键词 摩擦纳米发电机 伞型 振动能收集 高能量密度 叠加输出
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抗阻运动改善超重肥胖人群身体成分:一项伞形综述 被引量:3
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作者 代新语 闫纪红 +1 位作者 华凌军 郑晓鸿 《中国组织工程研究》 CAS 北大核心 2024年第2期267-271,共5页
背景:抗阻运动可以增加肌肉质量、提升肌肉力量,但对体成分的相关影响缺乏确凿证据,随机对照试验与多篇Meta分析结果的争议给临床的运动干预决策带来了困扰。目的:基于伞形综述(umbrella review)的方法学范式,探究抗阻运动改善超重、肥... 背景:抗阻运动可以增加肌肉质量、提升肌肉力量,但对体成分的相关影响缺乏确凿证据,随机对照试验与多篇Meta分析结果的争议给临床的运动干预决策带来了困扰。目的:基于伞形综述(umbrella review)的方法学范式,探究抗阻运动改善超重、肥胖人群体成分的干预效果及安全性。方法:检索PubMed、Cochrane Library、Web of Science、中国知网等数据库,中文检索词包括“抗阻、阻力、自重、meta、元分析、meta分析、体成分、体脂率、脂肪质量、瘦体重、体质量”,英文检索词包括“Resistance training、Strength Training、Weight-Lifting Strengthening Program、Body Compositions、Body Fat Distribution、Meta Analysis、Data Pooling、Overviews、Clinical Trial、Clinical Trial Overviews”等。收集抗阻运动干预超重、肥胖人群的系统评价,检索时限均从各数据库建库至2022-08-31。采用PRISMA评价纳入研究的方法学质量,采用GRADE评价系统对证据质量进行分级。结果与结论:①最终纳入14篇Meta分析,GRADE证据质量评价显示,2个结局指标证据质量为中级,12个为低级,14个为极低级。②与对照组相比,32个结局指标中有23个得到显著性改善。抗阻运动对体脂率的干预效果已形成共识,对瘦体质量、体质量指数、内脏脂肪的干预效果仍需进一步证实。③抗阻运动是改善超重、肥胖人群体成分的一种有效安全的方法,纳入系统评价的整体研究质量和结局指标证据质量普遍较低,未来应在明确样本特征、细化方案设计的基础上,充分结合被试的初始状态、运动目标和意愿,通过水阻、气阻及弹性阻力的多元、科学、个性化的运动处方设计提升抗阻运动的安全性和依从性,为抗阻运动干预提供明确的循证支持与决策依据。 展开更多
关键词 抗阻运动 体脂率 体成分 超重肥胖人群 伞形综述 系统评价再评价
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鸟啄损伤对复合绝缘子运行性能的影响研究
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作者 卢明 高超 +3 位作者 杨曜成 李黎 盛从兵 张世尧 《绝缘材料》 CAS 北大核心 2024年第3期113-120,共8页
复合绝缘子因其性能优越得以在电网领域广泛应用,目前由于鸟类数量增加,鸟啄复合绝缘子的情况日益严重,鸟啄后绝缘子结构遭到破坏,会造成电网线路故障,因此本文研究鸟啄损伤对复合绝缘子性能的影响,为电网运维管理提供参考。首先通过试... 复合绝缘子因其性能优越得以在电网领域广泛应用,目前由于鸟类数量增加,鸟啄复合绝缘子的情况日益严重,鸟啄后绝缘子结构遭到破坏,会造成电网线路故障,因此本文研究鸟啄损伤对复合绝缘子性能的影响,为电网运维管理提供参考。首先通过试验对复合绝缘子鸟啄后机电性能进行分析;然后通过人工模拟鸟啄伞裙损伤来研究不同受损占比、不同受损数量对复合绝缘子沿面电场强度与污闪电压的影响;最后开展复合绝缘子护套电蚀损实验、酸浸实验、热老化试验,评估护套损伤对复合绝缘子性能的影响规律。结果表明:鸟啄后复合绝缘子结构遭到破坏,其电气性能、力学性能和防污性能都受到影响,同时护套损伤后,在局部场强、水分、酸、放电产热、机械应力等诸多因素共同作用下,芯棒材料劣化降解,芯棒力学性能下降,存在复合绝缘子异常断裂的风险。 展开更多
关键词 复合绝缘子 鸟啄损伤 伞裙损伤 护套损伤
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甲状腺相关眼病治疗中不同单克隆抗体有效性与安全性的系统评价再评价
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作者 刘爽 蒋函錞 +1 位作者 吴晶晶 赵荣生 《中国临床药理学与治疗学》 CAS CSCD 北大核心 2024年第7期735-743,共9页
目的:全面评估甲状腺相关眼病(thyroidassociated ophthalmopathy,TAO)治疗中利妥昔单克隆抗体(rituximab,RTX)、托珠单克隆抗体(tocilizumab,TCZ)、替妥木单克隆抗体(teprotumumab,TMB)的有效性和安全性。方法:采用系统评价再评价方法... 目的:全面评估甲状腺相关眼病(thyroidassociated ophthalmopathy,TAO)治疗中利妥昔单克隆抗体(rituximab,RTX)、托珠单克隆抗体(tocilizumab,TCZ)、替妥木单克隆抗体(teprotumumab,TMB)的有效性和安全性。方法:采用系统评价再评价方法,系统检索PubMed、Embase、Cochrane Library数据库中关于TAO治疗的系统评价/Meta分析,检索时间均为建库至2024年1月。分别采用PRISMA 2020声明、AMSTAR 2量表和GRADE工具评估纳入研究的报告质量、方法学质量及证据质量。结果:当前关于TAO治疗中3种单克隆抗体的系统评价在报告规范性、方法学质量和证据质量方面仍存在不足。目前仍缺少3种单克隆抗体直接比较的证据,基于间接比较证据,TCZ可能是最好的治疗方法,其次为TMB和RTX。有效性方面,TCZ、TMB可显著降低临床活动性评分、眼球突出度及生活质量,TCZ显著降低复视发生,RTX显著降低疾病应答,RTX及TCZ显著改善疾病失活率,RTX在复视、眼睑裂变化、NOSPECS评分与生活质量方面无显著差异。安全性方面的结论尚不一致,TCZ和TMB可能增加不良事件的发生率,而RTX在安全性方面与糖皮质激素或安慰剂相比无显著差异。结论:本研究为TAO治疗中3种单克隆抗体的选择提供循证依据。尽管TCZ在有效性方面可能具有优势,但考虑到现有证据的限制性,未来仍需更多高质量研究进一步验证和比较不同单克隆抗体在TAO治疗中的有效性和安全性。 展开更多
关键词 甲状腺相关眼病 利妥昔单克隆抗体 托珠单克隆抗体 替妥木单克隆抗体 伞形综述
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改进YOLOv5混合样本训练的绝缘子伞盘脱落缺陷检测方法 被引量:1
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作者 李洵 甘润东 +3 位作者 钱俊凤 张世恒 赵文彬 王道累 《计算机工程与应用》 CSCD 北大核心 2024年第4期289-297,共9页
为了实现输电线路巡检时绝缘子串及伞盘脱落缺陷的精准定位和识别,提出了一种基于改进YOLOv5混合样本训练的绝缘子缺陷检测模型。针对绝缘子缺陷图像稀少问题,提出了一种混合样本数据生成方法,通过将GrabCut算法与图像融合技术相结合实... 为了实现输电线路巡检时绝缘子串及伞盘脱落缺陷的精准定位和识别,提出了一种基于改进YOLOv5混合样本训练的绝缘子缺陷检测模型。针对绝缘子缺陷图像稀少问题,提出了一种混合样本数据生成方法,通过将GrabCut算法与图像融合技术相结合实现数据集的扩充。针对绝缘子及缺陷的外形特点,利用长边定义法和环形平滑标签(circular smooth label,CSL)重新定义模型特征提取区域的坐标参数。通过增加角度信息,实现更加精确化的特征提取。通过将主干网络(Backbone)中部分特征层与路径聚合网络(path aggregation network,PAN)提取的特征相融合,对CSPDarkNet主干网络进行优化。改进后的YOLOv5 CSPDarkNet模型相较于改进前绝缘子缺陷检测精度提升了2.8个百分点,检测速率为20.5 FPS。实验结果表明,改进的绝缘子缺陷识别方法基本满足实际应用需求。 展开更多
关键词 特征融合 YOLOv5 旋转框 伞盘脱落缺陷
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国外新一代飞船回收着陆系统设计综述
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作者 余抗 尹钊 +3 位作者 马俊峰 罗太超 盛一诺 郝平 《载人航天》 CSCD 北大核心 2024年第2期252-260,共9页
为开展大规模的商业航天活动并瞄准未来载人深空探测任务,美国加紧研制了以洛克希德·马丁公司的猎户座飞船、波音公司的星际航线飞船和星际探索公司的载人龙飞船为代表的新一代载人飞船,该类飞船均采用由多个降落伞组成的群伞系统... 为开展大规模的商业航天活动并瞄准未来载人深空探测任务,美国加紧研制了以洛克希德·马丁公司的猎户座飞船、波音公司的星际航线飞船和星际探索公司的载人龙飞船为代表的新一代载人飞船,该类飞船均采用由多个降落伞组成的群伞系统进行着陆前减速、配置着陆缓冲气囊或倾斜飞船返回舱姿态实现低冲击着陆和无损回收,以达到飞船返回舱可重复使用并提升航天员着陆舒适度的目的。从工程应用角度出发,调研了国外新一代飞船回收着陆功能的方案设计、技术指标体系、产品参数和技术验证情况,从系统层面对其设计思想进行归纳总结,梳理出国外新一代载人飞船回收着陆功能的研制进展及发展趋势,以期为中国开展相关研制工作提供参考。 展开更多
关键词 新一代飞船 回收着陆设计 群伞系统 低冲击着陆
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