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Experimental and analytical investigation on friction resistance force between buried coated pressurized steel pipes and soil

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 615-629页

作者： Shaurav ALAM Tanvir MANZUR john MATTHEWS Chris BARTLETT Erez ALLOUCHE brent KEIL john KRAFT Department of Civil Engineering and Construction Engineering Technology Louisiana Tech UniversityRustonLA 71270USA Department of Civil Engineering Bangladesh University of Engineering and TechnologyDhaka 1000Bangladesh Georgia Tech Research Institute AtlantaGA 30332USA Stantec Inc. Edmonton T5J0K4Canada North West Pipe Company VancouverWA 98684USA

This paper presents an analytical approach for estimating frictional resistance to pipe movement at soil and external pipe surface of buried coated pressurized steel pipes relative to the internal thrust *** proposed analytical method was developed based on 36 experiments,which involved three coating types(cement mortar(CM),polyurethane type-I(PT-I),prefabricated plastic tape(PPT))on pipes’surfaces,three different soils(pea-gravel(PG),sand(S),silty-clay(SC)),and four simulated over burden depths above the pipe’s *** showed frictional resistance decreased with increasing over burden depth above the pipe’s *** degree of frictional resistance at the pipe-soil interface was found to be in the order of PG>SC>S for all coating variations and overburden *** coated pipe buried in all three types of soil produced significantly higher frictional resistance as compared to other coating *** on experimental data,the developed analytical introduced a dimensionless factor“Z”,which included effects of types of coatings,soil,and overburden depths for simplified rapid *** showed that the method provided a better prediction of frictional resistance forces,in comparison to previous analytical methods,which were barely close in predicting friction resistance for different coating variations,soil types,and overburden *** resistance force values reported herein could be considered conservative.

关键词： friction resistance force thrust force coated pressurized steel pipe soil type overburden depth

Performance on the Functional Movement Screen in older active adults

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journal of Sport and Health Science 2016年第1期5卷 119-125页

作者： Ulrike H.Mitchell A.Wayne johnson Pat R.Vehrs j.brent Feland Sterling C.Hilton Department of Exercise Sciences Brigham Young University Provo UT 84602 USA Department of Educational Leadership and Foundations David O. McKay School of Education Brigham Young University Provo UT 84602 USA

Background:The Functional Movement Screen(FMS^(TM)) has become increasingly popular for identifying functional limitations in basic functional *** exploratory and descriptive study was undertaken to confirm feasibility of performing the FMS^(TM) in older active adults,assess prevalence of asymmetries and to evaluate the relationship between functional movement ability,age,physical activity levels and body mass index(BMI).Methods:This is an observational study;97 men(n = 53) and women(n = 44) between the ages of 52 and 83 *** was computed and self-reported physical activity levels were *** were grouped by age(5-year intervals),BMI(normal,over-weight,and obese)and *** participant's performance on the FMS^(TM) was digitally recorded for later ***:The youngest age group(50–54 years) scored highest in all seven tests and the oldest age group(75+) scored lowest in most of the tests compared to all other age *** subjects in the 'normal weight' group performed no different than those who were in the 'overweight' group;both groups performed better than the 'obese' *** the 97 participants 54 had at least one *** pairwise correlations between the total FMS^(TM) score and age(r =-0.531),BMI(r =-0.270),and the measure of activity level(r = 0.287) were significant(p juries in the older population.

关键词： Age BMI Fitness level FMS^(TM) Functional fitness Functional limitations

(U-Th)/He技术约束下库车盆地北缘构造热演化——以吐孜2井为例

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地球物理学报 2014年第1期57卷 62-74页

作者：喻顺陈文吕修祥 Noreen Evans brent McInnes 尹继元孙敬博李洁中国地质科学院地质研究所同位素热年代学实验室北京100037 大陆构造与动力学国家重点实验室北京100037 中国石油大学(北京)地球科学学院北京1022494 john De Laeter Center for Isotope Research Applied Geology/Applied PhysicsCurtin University

库车前陆盆地蕴藏着丰富的油气资源,然而盆地中新生代的构造热演化史一直缺乏有效的研究,制约了油气的勘探.本文测试了吐孜2井磷灰石、锆石(U-Th)/He年龄数据,建立了He年龄随现今温度/深度变化的关系,确定该区磷灰石(U-Th)/He体系封闭... 详细信息

库车前陆盆地蕴藏着丰富的油气资源,然而盆地中新生代的构造热演化史一直缺乏有效的研究,制约了油气的勘探.本文测试了吐孜2井磷灰石、锆石(U-Th)/He年龄数据,建立了He年龄随现今温度/深度变化的关系,确定该区磷灰石(U-Th)/He体系封闭温度为89℃.综合利用(U-Th)/He及镜质体反射率(Ro)数据模拟恢复了库车盆地吐孜2井中新生代热演化史,结果表明库车盆地吐孜洛克背斜形成起始时间约为5Ma,新生代抬升剥蚀量平均约为670m,平均抬升剥蚀速率为0.133mm/a.根据新生代吐孜洛克背斜的构造演化分析确定了气源断裂活动及圈闭形成的时期,揭示了吐孜洛克背斜天然气成藏时间为5Ma以后,且烃源岩生排烃、断裂活动及圈闭形成的时间具有良好的匹配关系,这是吐孜洛克油气田形成的关键因素之一.本文应用(U-Th)/He技术研究沉积盆地构造热演化史,对库车盆地油气勘探具有重要的意义.

关键词： He封闭温度构造热演化隆升剥蚀库车盆地

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国外旅游扶贫研究进展

人文地理 2015年第1期30卷 26-32页

作者：李会琴侯林春杨树旺 j R brent Ritchie 中国地质大学经济管理学院武汉430074 卡尔加里大学Haskayne商学院中国地质大学公共管理学院武汉430074

在相关概念辨析的基础上,对国外旅游扶贫理论、实践模式、效果、研究方法、相关国际组织的作用进行了综述。国外旅游扶贫形成了较为系统的理论体系与研究框架,为旅游实践提供了理论支持。从研究内容看,自然旅游、遗产旅游、农业旅游、... 详细信息

在相关概念辨析的基础上,对国外旅游扶贫理论、实践模式、效果、研究方法、相关国际组织的作用进行了综述。国外旅游扶贫形成了较为系统的理论体系与研究框架,为旅游实践提供了理论支持。从研究内容看,自然旅游、遗产旅游、农业旅游、社区旅游是旅游扶贫的主要方式;从扶贫效果看,旅游扶贫对当地经济有较大的促进作用,但需要合理的规划与操控才能可持续。旅游扶贫研究方法以宏观的定量研究为主,研究案例呈现地理集中性。今后应加强城市贫困问题、精准旅游扶贫及中国旅游扶贫案例的研究。

关键词：旅游扶贫社区旅游研究进展国外

Photonic radio frequency channelizers based on Kerr optical micro-combs

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journal of Semiconductors 2021年第4期42卷 17-32页

作者： Mengxi Tan Xingyuan Xu jiayang Wu Thach G.Nguyen Sai T.Chu brent E.Little Roberto Morandotti Arnan Mitchell David j.Moss Optical Sciences Centre Swinburne University of TechnologyHawthornVIC 3122Australia Electro-Photonics Laboratory Department of Electrical and Computer Systems EngineeringMonash UniversityVIC3800Australia School of Engineering RMIT UniversityMelbourneVIC 3001Australia Department of Physics City University of Hong KongHong KongChina State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision MechanicsChinese Academy of ScienceXi'an 710119China INRS-Énergie Matériaux et Télécommunications1650 Boulevard Lionel-BouletVarennesQuébecJ3X 1S2Canada Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

We review recent work on broadband RF channelizers based on integrated optical frequency Kerr micro-combs combined with passive micro-ring resonator filters,with microcombs having channel spacings of 200 and 49 *** approach to realizing RF channelizers offers reduced complexity,size,and potential cost for a wide range of applications to microwave signal detection.

关键词： microwave photonic signal channelization integrated optical frequency comb

Orthogonally polarized RF optical single sideband generation with integrated ring resonators

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journal of Semiconductors 2021年第4期42卷 53-66页

作者： Mengxi Tan Xingyuan Xu jiayang Wu Thach G.Nguyen Sai T.Chu brent E.Little Arnan Mitchell Roberto Morandotti David j.Moss Optical Sciences Centre Swinburne University of TechnologyHawthornVIC 3122Australia Electro-Photonics Laboratory Department of Electrical and Computer Systems EngineeringMonash UniversityVIC3800Australia School of Engineering RMIT UniversityMelbourneVIC 3001Australia Department of Physics City University of Hong KongHong KongChina State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision MechanicsChinese Academy of ScienceXi'an 710119China INRS-Énergie Matériaux et Télécommunications1650 Boulevard Lionel-BouletVarennesQuébecJ3X 1S2Canada Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China

We review recent work on narrowband orthogonally polarized optical RF single sideband generators as well as dualchannel equalization,both based on high-Q integrated ring *** devices operate in the optical telecommunications C-band and enable RF operation over a range of either fixed or thermally tuneable *** operate via TE/TM mode birefringence in the *** achieve a very large dynamic tuning range of over 55 dB for both the optical carrier-to-sideband ratio and the dual-channel RF equalization for both the fixed and tunable devices.

关键词： microwave photonics micro-ring resonators radio frequency

The effects of selection for cold tolerance on cross-tolerance to other environmental stressors in Drosophila melanogaster

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Insect Science 2009年第3期16卷 263-276页

作者： Heath A. MacMillan jillian P. Walsh brent j. Sinclair Department of Biology The University of Western Ontario London ON N6A 5B7 Canada

Cross tolerance, whereby tolerance to one environmental stress is correlated with tolerance to other stressors, is thought to be widespread in insects. We used lines of Drosophila melanogaster Meigen （Diptera： Drosophilidae） selected for survival at a 1-h exposure to -5℃ to examine the extent to which this selection results in increased tolerance to other stresses, including high and low temperatures, desiccation and starvation. While selection improved tolerance to acute cold exposure and survival at -5℃, there was little effect of selection regime on tolerance to other stressors. There was no correlation between tolerances to any of the stressors, suggesting different mechanisms of tolerance. This supports arguments that correlations between stress tolerances during selection experiments with D. melanogaster may be coincidental. The magnitude of heat-hardening was apparently constrained by basal tolerance among lines, but the magnitude of the rapid cold-hardening response was not correlated with basal cold tolerance, implying that the relationship between inducible and basal tolerances differs at high and low temperatures.

关键词： chill coma cold tolerance cross-tolerance desiccation heat shock high temperature laboratory selection longevity rapid cold hardening starvation

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无连接器探头在机械和电气方面的优点

今日电子 2005年第10期 43-44,48页

作者： brent Holcombe Brock j.LaMeres Agilent Technologies公司

随着数字信号数据率的继续增加,以往标准的逻辑分析探头技术已不能很好适应。在机械和电气方面,无连接器探头都超过了Mictor探头,传统Mictor探头正在被无连接器探头技术所取代。

关键词：连接器探头电气机械数字信号逻辑分析数据率技术

低维生素D水平被当作癌症危险因子新的研究证据不支持补充维生素D能够预防癌症

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英国医学杂志中文版 2018年第2期21卷 65-66页

作者： Despoina Manousaki j.brent Richards 任倩 Centre for Clinical Epidemiology Department of Epidemiology Lady Davis Institute for Medical ResearchJewish GeneralHospital McGill UniversityMontreal QuebecCanada Departments of Medicine Human GeneticsEpidemiology and Biostatistics JewishGeneral HospitalMcGill UniversityMontreal QuebecCanada Department of Twin Research and Genetic Epidemiology King's College LondonLondon UK 北京大学人民医院内分泌科

尽管仍存在争议，但是目前初级预防依然是临床上最有效的降低癌症负担的方式。其中一种很有潜力的策略就是治疗维生素D缺乏症，因为流行病学和动物实验研究发现低水平维生素D和癌症的风险增高相关2-30而且维生素D缺乏症患者比例达到总... 详细信息

尽管仍存在争议，但是目前初级预防依然是临床上最有效的降低癌症负担的方式。其中一种很有潜力的策略就是治疗维生素D缺乏症，因为流行病学和动物实验研究发现低水平维生素D和癌症的风险增高相关2-30而且维生素D缺乏症患者比例达到总人群的40％。并且很容易通过简单的血液检测进行诊断，

关键词：低维生素D 癌症预防措施临床研究