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Finite Element Analysis of Femoral Strains in Older Adults During Stair Ascent and Descent

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Journal of Science in Sport and Exercise 2022年第2期4卷 168-179页

作者： chen Deng Jason C.Gillette Timothy R.derrick Division of Sport Biomechanics School of Sport ScienceBeijing Sport UniversityNo.48Xinxi RoadBeijing 100084People’s Republic of China Department of Kinesiology Iowa State UniversityAmesIAUSA

Purpose Understanding the femur load environment during daily activity is necessary for the understanding of risk of femoral pain,pain related falls,and femoral fractures,which could help the design of osteogenic exercises or the preventa-tive methods for older *** Using the finite element femur analysis,this study was to estimate the femoral strains at 9 cross-sections along the long axis of femur for stair ascent and descent(n=17;age:50-65 years).Motion analysis and inverse dynamics were com-bined with musculoskeletal modelling and optimization,then were used as input to a 3-D femur model to estimate femoral *** at the hip contact force peaks were *** The compressive and tensile strains during stair descent were greater than ascent for all or most cross-sections,especially for the proximal cross-sections of the femur:stair ascent produced−324.0±103.8 to−483.7±191.0μεcompressive strains and descent produced−608.8±288.4 to 1016.0±444.1με;stair ascent produced 336.2±105.4 to 391.8±136.9μεtensile strains and descent produced 546.9±252.8 to 741.7±333.6με.Conclusion Strains represent the material deformation effect on the bone due to the sum of all the bone external *** bone strains could help future studies analyze load conditions in a more comprehensive way for other physical activities,which predicts the risk of stress fractures and tests if alternative methods(gait type change)could reduce stress and strain effectively.

关键词： Femoral cross-sections Finite element method Bone strains Stair ascent and descent Older adults

Development,validation and comparison of multivariable risk scores for prediction of total stroke and stroke types in Chinese adults:a prospective study of 0.5 million adults

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Stroke & Vascular Neurology 2022年第4期7卷 328-336,I0023-I0045页

作者： Matthew Chun Robert Clarke Tingting Zhu David Clifton derrick A Bennett Yiping chen Yu Guo Pei Pei Jun Lv Canqing Yu Ling Yang Liming Li Zhengming chen Benjamin J Cairns 无 Clinical Trial Service Unit and Epidemiological Studies Nuffield Department of Population HealthUniversity of OxfordOxfordUK Department of Engineering Science University of OxfordOxfordUK Department of Biomedical Engineering Oxford-Suzhou Centre for Advanced ResearchSuzhouChina Medical Research Council Health Research Unit Nuffield Department of Population HealthUniversity of OxfordOxfordUK CKB Project Department Fuwai Hospital Chinese Academy of Medical SciencesNational Center for Cardiovascular DiseasesBeijingChina CKB Project Department Chinese Academy of Medical SciencesBeijingChina Department of Epidemiology and Biostatistics School of Public HealthPeking UniversityBeijingChina Department of Epidemiology Peking University Center for Public Health and Epidemic Preparedness and ResponseBeijingChina On behalf of the China Kadoorie Biobank Collaborative Group

Background and purpose Low-income and middle-income countries have the greatest stroke burden,yet remain *** study compared the utility of Framingham versus novel risk scores for prediction of total stroke and stroke types in Chinese *** China Kadoorie Biobank(CKB)is a prospective study of 512726 adults,aged 30-79 years,recruited from 10 areas in China in *** 1 January 2018,43234 incident first stroke cases(36310 ischaemic stroke(IS);8865 haemorrhagic stroke(HS))were recorded in 503842 participants with no history of stroke at *** compared the predictive utility of the Framingham Stroke Risk Profile(FSRP)with novel CKB stroke risk scores and included recalibration,refitting,stratifying by study area and addition of other risk *** was assessed using area under the receiver operating characteristic curve(AUC)and calibration was assessed using Greenwood-Nam-D’Agostinoχ^(2) *** Incidence of total stroke varied fivefold by area in *** FSRP had good discrimination for total stroke(AUC(95%CI);men:0.78(0.77 to 0.79),women:0.77(95%CI 0.76 to 0.78)),but poor calibration(χ^(2);men:1,825,women:3,053),substantially underestimating absolute *** reducedχ^(2) by>80%,but did not improve *** the FSRP did not materially improve discrimination,but further improved *** by area improved discrimination(AUC;men:0.82(0.82 to 0.83);women:0.82(0.82 to 0.83)),but not *** other risk factors yielded modest,but statistically significant,improvements in the *** findings for IS and HS were similar to those for total *** The FSRP reliably differentiated Chinese adults with incident stroke,but substantially underestimated the absolute risks of *** local risk prediction equations that took account of differences in stroke incidence within China enhanced risk prediction of total stroke and major stroke pathological type

关键词： prediction income absolute

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冻结立井井筒机械化掘进现状及发展趋势

煤炭科学技术 2024年第9期52卷 1-17页

作者：陈湘生王恒宋朝阳陈汉青陈曦丁航王磊煤炭科学研究总院北京100013 矿山深井建设技术国家工程研究中心北京100013 深圳大学土木与交通工程学院广东深圳518060 煤炭智能开采与岩层控制全国重点实验室北京100013

针对我国“富煤贫油少气”的能源赋存结构及煤炭未来一段时间将长期占据能源消耗主导地位的特点,回顾了我国煤炭井工开采领域冻结立井井筒机械化掘进发展历程。钻爆法凿井作为我国立井井筒施工的主要工法,炸药的应用大幅提高了冻结井筒... 详细信息

针对我国“富煤贫油少气”的能源赋存结构及煤炭未来一段时间将长期占据能源消耗主导地位的特点,回顾了我国煤炭井工开采领域冻结立井井筒机械化掘进发展历程。钻爆法凿井作为我国立井井筒施工的主要工法,炸药的应用大幅提高了冻结井筒的掘进效率,配套的伞钻打孔、抓岩机装岩、大型井架及设备提升、大模板砌壁等大型机械化设备的应用,大幅提高了井筒成井速度;竖井钻机、反井钻机及竖井掘进机作为特殊地层条件下立井井筒特殊凿井方式,也有各自应用范围。面对我国西部富水弱胶结地层特点及智慧矿山发展趋势,采用冻结+钻爆法施工难以满足千米级弱胶结岩层立井井筒智能化无人化的建设需求,而采用冻结+竖井掘进机钻井是未来超深立井井筒技术发展方向之一。结合国外冻结+竖井掘进机凿井工程案例,针对我国西部富水弱胶结岩层立井井筒建设,提出了冻结+竖井掘进机凿井在冻结壁厚度和强度设计理论、双层钢筋混凝土井壁永久支护、低温环境下竖井掘进机掘进破岩形式以及分级上排渣方式等冻-掘-支-运协同作业方面提出了合理化建议;明确了井壁结构与弱胶结围岩相互作用机理,优化双层井壁结构方法,构建竖井掘进机掘-支-运同步作业模式等,提升井筒建设综合效率,提高信息化水平,推动立井井筒向机械化、绿色化和智能化发展。

关键词：特殊凿井机械破岩冻结井壁竖井掘进机

Potential Association between Soil and Leaf Chemical Properties, and Soybean Seed Composition

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Agricultural Sciences 2014年第6期5卷 560-570页

作者： Luciano M. Jaureguy Pengyin chen Kristofor Brye derrick Oosterhuis Andy Mauromoustakos John R. Clark Agricultural Statistics Laboratory University of Arkansas Fayetteville USA Department of Crop Soil and Environmental Sciences University of Arkansas Fayetteville USA

Maximizing the expression of seed quality traits by understanding how they are affected by environmental variables may help develop high quality nutritious soybeans. Eight specialty soybean breeding lines were grown at two Arkansas locations differing by soil texture, with three replications in 2011. Before the reproductive period, soil and leaf samples were collected from each plot. Soil samples were analyzed for particle size distribution, electrical conductivity, pH, and a set of extractable nutrients from the top 12.5 cm, while leaf samples were analyzed for the same set of nutrients as the soil samples. At maturity, seed samples were analyzed for the same set of nutrients as were leaf and soil samples, plus protein, oil, fatty acids, and sugars. All leaf elements were within the adequate levels for soybean production at both locations. Overall, seed composition of breeding lines did not differ among locations and no significant changes in breeding line ranking among locations were observed. Attempting to modify seed composition by nutrient fertilization may not be profitable, as no direct relationships were observed between leaf or soil chemical properties, and seed composition. These findings may provide a starting point for future studies on fertilization and management practices that improve soybean seed quality.

关键词： Soybean Seed Composition Soil Properties

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大型竖井凿井大临工程快速施工实践与探讨

建井技术 2024年第2期45卷 30-33页

作者：陈杰王杰铜陵有色金属集团铜冠矿山建设股份有限公司安徽铜陵244000

在山东黄金集团焦家金矿朱郭李家副井井筒凿井大临工程施工中,采用整体钢结构组合模板进行井架基础施工,利用砖砌墙支撑设备整体浇筑和凿井井架整体吊装。通过合理地布置施工顺序、优化基础施工方法和科学管理等措施,在工期、质量和安... 详细信息

在山东黄金集团焦家金矿朱郭李家副井井筒凿井大临工程施工中,采用整体钢结构组合模板进行井架基础施工,利用砖砌墙支撑设备整体浇筑和凿井井架整体吊装。通过合理地布置施工顺序、优化基础施工方法和科学管理等措施,在工期、质量和安全等方面取得了非常好的效果,实现了立井大临工程快速优质施工的目标。

关键词：竖井凿井工程设备基础快速施工施工顺序

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内爬式塔式起重机基础施工技术

建筑技术开发 2024年第10期51卷 28-30页

作者：陈业伟中建四局建设发展有限公司福建厦门361000

近年来,随着我国城市化进场加快,超高层建筑的应用也逐渐增多,塔式起重机已成为建造超高层结构垂直运输的常规手段。塔式起重机基础设置、塔式起重机选择均成为超高层建筑一项必修的课题。通过对南昌市朝阳新城1号塔式起重机基础专项施... 详细信息

近年来,随着我国城市化进场加快,超高层建筑的应用也逐渐增多,塔式起重机已成为建造超高层结构垂直运输的常规手段。塔式起重机基础设置、塔式起重机选择均成为超高层建筑一项必修的课题。通过对南昌市朝阳新城1号塔式起重机基础专项施工经验进行总结,在考虑整体工期以及穿插施工作业的影响时采用内爬式施工技术,有效缩短了工期。结合预埋固定钢托座的方式进行塔式起重机基础的施工,并对桩基施工和土方开挖进行了详细的讨论。

关键词：塔式起重机内爬升预埋桩基

Fresh fruit consumption and diabetes: a prospective cohort study of 0.5 million adults in the China Kadoorie Biobank

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Fresh fruit consumption and diabetes: a prospective cohort s...

第十二届全国营养科学大会

作者： Huaidong Du Liming Li derrick A.Bennett Yu Guo Zheng Bian Junshi chen Tim Key Rory Collins Richard Peto Zhengming chen CTSU Nuffield Department of Population HealthUniversity of Oxford Chinese Academy of Medical Sciences School of Public Health Peking University

Background:Several studies in Western populations have observed that a higher consumption of fruit could help to prevent diabetes incidence,but no such beneficial effect has been reported from *** importantly,to date there is little direct evidence about the associations of fruit consumption with mortality and incidence of

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法兰连接双曲高耸塔桅钢结构安装技术研究

空间结构 2024年第1期30卷 62-69,61页

作者：刘荣才陈安英黄荣鑫宋怀祥邱晖安徽天成建设有限公司安徽六安237005 合肥工业大学安徽合肥230009 青岛东方铁塔股份有限公司山东青岛266000 六安市重点工程建设管理处安徽六安237008 中广电广播电影电视设计研究院北京100045

以六安市308 m广播电视塔高耸塔桅钢结构为工程背景,综合考虑结构安装特点与场地布置条件,提出采用大型外附着式塔吊与扒杆组合的方式完成法兰连接双曲高耸塔桅钢结构安装,形成塔身、塔楼及桅杆的钢结构分部安装施工技术.利用有限元软... 详细信息

以六安市308 m广播电视塔高耸塔桅钢结构为工程背景,综合考虑结构安装特点与场地布置条件,提出采用大型外附着式塔吊与扒杆组合的方式完成法兰连接双曲高耸塔桅钢结构安装,形成塔身、塔楼及桅杆的钢结构分部安装施工技术.利用有限元软件分析主体结构施工阶段的受力与变形情况,并结合监测数据与规范限值进行对比分析;对塔吊附着与扒杆在施工吊装中的安全性进行数值模拟验算.结果表明:研究提出的钢结构施工安装技术具有很好的适用性,安装精度高,可以有效控制安装过程中变形偏差问题;塔吊附墙与扒杆在吊装过程中满足安全要求,有效解决高耸塔桅钢结构吊装安全问题,可为同类工程施工起到借鉴作用.

关键词：高耸钢结构安装技术变形控制有限元分析安全验算

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XXJ20Y电动斜直井修井机的研制与应用

石油机械 2024年第4期52卷 129-135页

作者：周华刘牧洲陈波郭新维艾白布·阿不力米提中国石油新疆油田公司应急抢险救援中心

为满足斜直水平井修井作业需求和验证斜直井作业工艺参数,研制了XXJ20Y电动斜直井修井机。介绍了修井机的主要结构和原理,提出将油管作业空间由后端移至机身内的思路。创新对中方法和油管运移及摆放路线,设计相应的整机对中结构、井架... 详细信息

为满足斜直水平井修井作业需求和验证斜直井作业工艺参数,研制了XXJ20Y电动斜直井修井机。介绍了修井机的主要结构和原理,提出将油管作业空间由后端移至机身内的思路。创新对中方法和油管运移及摆放路线,设计相应的整机对中结构、井架结构和抓管、移管、排管结构。应用Pro/E和ANSYS Workbench 15.0等主流分析软件对井架和底座等关键零部件进行了三维建模和强度校核。该修井机进行了小规模的试验应用,达到了较高的自动化水平,操作手1人就可完成管柱起下作业,配合人员大幅减少,安全性提高;利用井场电源驱动,尾气零排放、噪声低,绿色环保;优化了油管运移结构及流程。该修井机的研制可为斜井修井机、电动修井机的研制和常规修井机的自动化改造提供借鉴。

关键词：电动斜直井修井机对中结构多向移动自动排放

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