检索结果-南通市图书馆

Effect of wear debris on fretting fatigue crack initiation

在线全文

学校读者我要写书评

暂无评论

Friction 2022年第6期10卷 927-943页

作者： shengjie wang Tongyan YUE Dagang wang Magd ABDEL WAHAB Soete Laboratory Department of Electrical EnergyMetalsMechanical Construction&SystemsFaculty of Engineering and ArchitectureGhent UniversityGhent 9052Belgium State Grid Xinyuan Maintenance Branch Beijing 100000China School of Mechatronic Engineering China University of Mining and TechnologyXuzhou 221116China Faculty of Engineering Van Lang UniversityHo Chi Minh City 700000Vietnam Soete Laboratory Ghent UniversityGhent 9052Belgium

Both wear and fatigue occur in fretting condition,and they interact with one another during the whole *** fatigue is commonly analysed without considering the effect of wear in partial slip regime,although wear affects the lifetime of crack *** paper investigates,for the first time,the effect of wear debris on fretting fatigue crack *** investigate the effect of debris,first fretting wear characteristics in partial slip regime are analysed for loading ***,the effect of wear on fretting fatigue crack initiation is investigated using Ruiz parameters and critical plane methods without considering the debris *** the results,we can see that loading conditions affect the wear profiles in different ***,wear has a significant effect on the fatigue in partial slip regime without considering debris especially on the crack initiation ***,considering wear debris in the analysis,its effect on critical plane parameters is *** is found that by considering the wear debris effect,the frtting fatigue crack initiation location is shifted towards the trailing *** predictions of both crack initiation location and lifetime show a good agreement with the experimental data.

关键词： fretting wear fretting fatigue critical plane Ruiz parameter debris

聚偏二氯乙烯薄膜引流管对兔腹腔术后肠粘连的预防效果及安全性分析

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

现代实用医学 2024年第8期36卷 1014-1017页

作者：王圣杰王安姜建帅宁波大学医学部宁波315211 宁波大学附属第一医院

目的观察聚偏二氯乙烯薄膜耦合腹腔引流管对新西兰兔腹腔术后肠粘连的预防效果,并评估其安全性。方法18只新西兰兔随机分为对照组和实验组,制作肠粘连模型后,实验组用聚偏二氯乙烯薄膜耦合腹腔引流管隔离损伤腹壁及损伤肠管,对照组不进... 详细信息

目的观察聚偏二氯乙烯薄膜耦合腹腔引流管对新西兰兔腹腔术后肠粘连的预防效果,并评估其安全性。方法18只新西兰兔随机分为对照组和实验组,制作肠粘连模型后,实验组用聚偏二氯乙烯薄膜耦合腹腔引流管隔离损伤腹壁及损伤肠管,对照组不进行隔离操作。术后21 d观察腹腔粘连程度,并对粘连组织进行病理切片观察。术后3 d检测小鼠肝肾功能、血常规、术后存活率及并发症,评估引流管安全性。结果实验组粘连程度评分低于对照组,组织增生和盲肠结构破坏较对照组轻(均P0.05)。结论聚偏二氯乙烯薄膜耦合腹腔引流管能预防新西兰兔腹部术后肠粘连的形成,且安全有效。

关键词：肠粘连聚偏二氯乙烯薄膜新西兰兔

Dynamic response to climate change in the radial growth of Picea schrenkiana in western Tien Shan,China

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2022年第1期33卷 147-157页

作者： Liang Jiao shengjie wang Ke Chen Xiaoping Liu College of Geography and Environment Science Northwest Normal UniversityLanzhou 730070People’s Republic of China Faculty of Geographical Science Beijing Normal UniversityBeijing 100875People’s Republic of China

Forests are important ecosystems for economic and social ***,the response of tree radial growth to climate has produced‘divergent problems'at high latitudes under global *** this study,the response stability and trend of Picea schrenkiana radial growth to variability in climate factors were analyzed in the mid-latitudes of the western Tien Shan *** growth of *** was mainly limited by minimum and mean *** divergent responses of radial growth occurred in response to the minimum and mean temperatures at the beginning of the growing season(April–May)of the current year,but responses to drought occurred in July–September of the previous *** the mean and minimum temperatures in June–September of the current year were both *** growth first increased and then decreased according to the basal area increment,with a gradual increase in ***,forest ecosystems in mountainous arid areas will be increasingly affected by future climate warming.

关键词： Dendroecology Divergent response Climate change Forest degradation Western Tien Shan mountains

铁尾矿砂蒸压加气轻质混凝土的制备与孔隙结构研究

在线全文

学校读者我要写书评

暂无评论

矿业研究与开发 2024年第3期44卷 232-238页

作者：王圣杰顾晓薇王屾宇廖晨曦陈明志王青东北大学资源与土木工程学院辽宁沈阳110819 东北大学智慧水利与资源环境科技创新中心辽宁沈阳110819

为改善因铁尾矿砂过量掺入而导致的蒸压加气轻质混凝土宏观孔隙结构劣化问题,研究发气剂(铝粉)掺量、发气剂与稳泡剂(羟丙基甲基纤维素)质量比对铁尾矿砂蒸压加气轻质混凝土宏观孔隙结构的调节作用,以及对试样抗压强度、体积密度、导热... 详细信息

为改善因铁尾矿砂过量掺入而导致的蒸压加气轻质混凝土宏观孔隙结构劣化问题,研究发气剂(铝粉)掺量、发气剂与稳泡剂(羟丙基甲基纤维素)质量比对铁尾矿砂蒸压加气轻质混凝土宏观孔隙结构的调节作用,以及对试样抗压强度、体积密度、导热性能的影响。结果表明,在发气剂和稳泡剂质量比为1∶5的情况下,发气剂掺量为0.09%时,铁尾矿砂蒸压加气轻质混凝土具有适中的抗压强度与体积密度,接近《蒸压加气混凝土砌块》(GB/T 11968—2020)规定的强度等级A2.5、体积密度等级B05的要求。在此基础上,进一步提高稳泡剂掺量至发气剂和稳泡剂质量比为1∶7可以有效提高小微孔隙(孔隙面积≤0.5mm^(2))占比,改善孔隙均匀性,降低孔隙联通率,使铁尾矿砂蒸压加气轻质混凝土单位体积密度下所能承受的压力提高5.19%,导热系数降低6.8%,具备更为优良的抗压及隔热性能。

关键词：铁尾矿砂蒸压加气轻质混凝土稳泡剂羟丙基甲基纤维素孔隙结构

1979—2021年新疆昆仑山北坡潜在蒸散时空变化研究

在线全文

学校读者我要写书评

暂无评论

干旱区地理 2024年第9期47卷 1443-1450页

作者：李红阳陈天宇王圣杰张明军西北师范大学地理与环境科学学院甘肃兰州730070 和田地区气象局新疆和田848000

蒸散是陆面水循环的重要环节,在高寒干旱环境中表现更加复杂。新疆昆仑山北坡位于青藏高原北缘,山区实地气象观测匮乏,对潜在蒸散的认识也有待加强。通过Mann-Kendall检验和经验正交函数分析了1979—2021年新疆昆仑山北坡潜在蒸散的时... 详细信息

蒸散是陆面水循环的重要环节,在高寒干旱环境中表现更加复杂。新疆昆仑山北坡位于青藏高原北缘,山区实地气象观测匮乏,对潜在蒸散的认识也有待加强。通过Mann-Kendall检验和经验正交函数分析了1979—2021年新疆昆仑山北坡潜在蒸散的时空变化特征,比较了各流域的变化趋势,并且分析了潜在蒸散与其他气象要素的关系。结果表明:(1)新疆昆仑山北坡年均潜在蒸散为733.5 mm,从塔里木盆地南缘向南呈现出逐渐减小的空间变化趋势。(2)1979—2021年潜在蒸散总体呈波动上升趋势,线性变化率为8.7 mm·(10a)^(-1),其中2007年以前呈上升趋势,2007年后有下降趋势。(3)在喀什噶尔河流域、叶尔羌河流域、和田河流域、克里雅河流域、车尔臣河流域以及库木库里盆地6个流域中,车尔臣河流域年均潜在蒸散最高(810.8 mm),其线性变化率也最大(11.4 mm·(10a)^(-1)),和田河流域和克里雅河流域潜在蒸散的升高趋势相对较小,线性变化率分别为4.9 mm·(10a)^(-1)和5.0 mm·(10a)^(-1)。未来仍应加强新疆昆仑山北坡高海拔区域的水文气象观测,以便明确全球变化背景下的水文不确定性。

关键词：潜在蒸散格网数据时空变化昆仑山北坡

同方期刊数据库

Glacier area shrinkage in China and its climatic background during the past half century

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2012年第1期22卷 15-28页

作者： ZHANG Mingjun wang shengjie LI Zhongqin wang Feiteng College of Geography and Environment Sciences Northwest Normal University State Key Laboratory of Cryospheric Sciences/Tianshan Glaciological Station Cold and Arid Regions Environmental and Engineering Research Institute CAS

Based on the glacier area variation records in the typical regions of China moni-tored by remote sensing, as well as the meteorological data of air temperature and precipitation from 139 stations and the 0℃ isotherm height from 28 stations, the glacier area shrinkage in China and its climatic background in the past half century was discussed. The initial glacier area calculated in this study was 23,982 km2 in the 1960s/1970s, but the present area was only 21,893 km2 in the 2000s. The area-weighted shrinking rate of glacier was 10.1%, and the interpolated annual percentage of area changes （APAC） of glacier was 0.3% a–1 since 1960. The high APAC was found at the Ili River Basin and the Junggar Interior Basin around the Tianshan Mountains, the Ob River Basin around the Altay Mountains, the Hexi Interior Basin around the Qilian Mountains, etc. The retreat of glacier was affected by the climatic background, and the influence on glacier of the slight-increased precipitation was counteracted by the significant warming in summer.

关键词： glacier area climate change China air temperature precipitation 0℃ isotherm height

Multiscale Analysis of the Effect of Debris on Fretting Wear Process Using a Semi-Concurrent Method

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2020年第1期62卷 17-35页

作者： shengjie wang Tongyan Yue Magd Abdel Wahab Soete Laboratory Faculty of Engineering and ArchitectureGhent UniversityTechnologiepark Zwijnaarde 903Zwijnaarde B-9052Belgium State Grid Xinyuan Maintenance Branch BeijingChina Division of Computational Mechanics Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Duc Thang UniversityHo Chi Minh CityVietnam

Fretting wear is a phenomenon,in which wear happens between two oscillatory moving contact surfaces in microscale *** this paper,the effect of debris between pad and specimen is analyzed by using a semi-concurrent multiscale ***,the macroscale fretting wear model is ***,the part with the wear profile is imported from the macroscale model to a microscale model after running in ***,an effective pad’s radius is extracted by analyzing the contact pressure in order to take into account the effect of the ***,the effective radius is up-scaled from the microscale model to the macroscale model,which is used after running in *** this way,the effect of debris is considered by changing the radius of the pad in the macroscale *** to the smaller number of elements in the microscale model compared with the macroscale model containing the debris layer,the semi-concurrent method proposed in this paper is more computationally ***,the results of this semi-concurrent method show a better agreement with experimental data,compared to the results of the model ignoring the effect of debris.

关键词： Fretting wear debris multiscale analysis semi-concurrent

昆仑山北坡地表水氢氧稳定同位素空间分布特征

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

干旱区地理 2024年第7期47卷 1127-1135页

作者：石玉东王圣杰张明军朱成刚车彦军西北师范大学地理与环境科学学院甘肃兰州730070 中国科学院新疆生态与地理研究所新疆乌鲁木齐830011 宜春学院地理科学系江西宜春336000

氢氧稳定同位素作为示踪剂被广泛用于水文循环过程研究。地表水是水循环的重要组成部分,是区域水汽来源和现代水文过程分析的有效载体。基于新疆第三次科学考察,于2018年8月至2023年8月在昆仑山北坡采集了地表水样本并测量其氢氧稳定同... 详细信息

氢氧稳定同位素作为示踪剂被广泛用于水文循环过程研究。地表水是水循环的重要组成部分,是区域水汽来源和现代水文过程分析的有效载体。基于新疆第三次科学考察,于2018年8月至2023年8月在昆仑山北坡采集了地表水样本并测量其氢氧稳定同位素数据,同时汇编了区域以往的地表水同位素数据,分析了昆仑山北坡地表水氢氧稳定同位素的空间分布特征。结果表明:(1)昆仑山北坡地表水同位素值呈现出西低东高的空间变化特征,区域地表水线为δ^(2)H=5.98×δ^(18)O-6.86(R^(2)=0.65,n=141)。(2)对比昆仑山北坡地表水和降水氢氧稳定同位素值发现地表水同位素平均值普遍低于加权降水同位素值。(3)昆仑山北坡地表水同位素空间格局受到西风携带的外来水汽和局地再循环水汽共同影响,此外蒸发也会改变区域地表水同位素值。

关键词：昆仑山北坡地表水氢氧稳定同位素新疆

Evaluating the soil evaporation loss rate in a gravel-sand mulching environment based on stable isotopes data

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2022年第8期14卷 925-939页

作者： YANG Ye ZHANG Mingjun ZHANG Yu wang shengjie wang Jiaxin College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China Key Laboratory of Resource Environment and Sustainable Development of Oasis Lanzhou 730070China

In order to cope with drought and water shortages,the working people in the arid areas of Northwest China have developed a drought-resistant planting method,namely,gravel-sand mulching,after long-term agricultural *** understand the effects of gravel-sand mulching on soil water evaporation,we selected Baifeng peach(Amygdalus persica L.)orchards in Northwest China as the experimental field in *** on continuously collected soil water stable isotopes data,we evaluated the soil evaporation loss rate in a gravel-sand mulching environment using the line-conditioned excess(lc-excess)coupled Rayleigh fractionation model and Craig-Gordon *** results show that the average soil water content in the plots with gravel-sand mulching is 1.86%higher than that without gravel-sand *** monthly variation of the soil water content is smaller in the plots with gravel-sand mulching than that without gravel-sand ***,the average lc-excess value in the plots without gravel-sand mulching is *** addition,the soil evaporation loss rate in the plots with gravel-sand mulching is lower than that in the plots without gravel-sand *** lc-excess value was negative for both the plots with and without gravel-sand mulching,and it has good correlation with relative humidity,average temperature,input water content,and soil water *** effect of gravel-sand mulching on soil evaporation is most prominent in *** with the evaporation data of similar environments in the literature,the lc-excess coupled Rayleigh fractionation model is *** isotopes evidence shows that gravel-sand mulching can effectively reduce soil water evaporation,which provides a theoretical basis for agricultural water management and optimization of water-saving methods in arid areas.

关键词： soil evaporation loss rate gravel-sand mulching stable isotopes line-conditioned excess coupled Rayleigh fractionation model Craig-Gordon model