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Validity and reliability of Chinese version of Fatigue Impact Scale in cerebral infarction patients 被引量:6
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作者 Chunwei Wu Zhandong Liu Yongbo Zhang Jimei Li Dexin Wang 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第2期177-181,共5页
BACKGROUND: Post-stroke fatigue has received much attention recently. Three evaluation scales are available, including the Fatigue Impact Scale (FIS). Yet none of these has been proven to be of use in the evaluatio... BACKGROUND: Post-stroke fatigue has received much attention recently. Three evaluation scales are available, including the Fatigue Impact Scale (FIS). Yet none of these has been proven to be of use in the evaluation of psychological quality after post-stroke fatigue. OBJECTIVE: To introduce FIS into China, and to evaluate the validity and reliability of the Chinese Version in patients with cerebral infarction. DESIGN: Scale evaluation. SETTING: Department of Rehabilitation, Beijing Friendship Hospital, Capital Medical University. PARTICIPANTS: A total of 330 patients with cerebral infarction were selected from the Department of Neurology, Beijing Friendship Hospital, Capital Medical University from June 2005 to December 2006. All patients met diagnostic standards from the Fourth National Cerebrovascular Disease Academic Meeting of China Medical Association and were diagnosed with CT or MRI examination. Patients who were not willing to accept scale evaluation were excluded. METHODS: The English version of FIS was translated into Chinese and subsequently translated back to English again. FIS was given to the discharged patients, and they returned them upon completion. In-patients completed and immediately returned the FIS. Validity and reliability of the retrieved scales were ascertained with descriptive and inference analysis. MAIN OUTCOME MEASURES: Total scores and subscale scores of FIS. RESULTS: Out of 330 questionnaires, 214 valid questionnaires were deemed valid in total. Six components were extracted in factor analysis, and the total cumulative contribution was 73.919%, which suggested the questionnaire was valid. After correlation analysis, 6 components were divided into 3 subscales, including cognitive, physical, and social, which was the same as the English version. The Cronbach α value for the three subscales was 0.937 7, 0.918 8, and 0.940 6, respectively (〉 0.7). CONCLUSION: The reliability and validity of the Chinese version of FIS met with satisfaction and appeared to be adaptable to cerebral infarction patients in China. 展开更多
关键词 cerebral infarction fatigue validity RELIABILITY scales
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Research on Analytical Method of Fatigue Characteristics of Soft Yoke Mooring System Based on Full-Scale Measurement 被引量:3
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作者 WU Wen-hua LV Bai-cheng +2 位作者 YUE Qian-jin ZHANG Yan-tao LIN Yang 《China Ocean Engineering》 SCIE EI CSCD 2017年第2期230-237,共8页
By focusing on the vulnerability of the structure of marine equipments, together with considering the randomness of meta-ocean load in statistics, a kind of analytical method of fatigue characteristics of marine struc... By focusing on the vulnerability of the structure of marine equipments, together with considering the randomness of meta-ocean load in statistics, a kind of analytical method of fatigue characteristics of marine structure based on full- scale and actual measurement of prototype is proposed. On the basis of short-term field measurement results of structural response, research is carried out on the fatigue analysis of hinge joints at the upper part of the Soft Yoke single point Mooring System (SYMS) by simultaneously monitoring the environmental load and considering the design criteria of offshore structure. Through analysis of finite element modeling, the time-histories of typical stress response are obtained, and then the assessment of fatigue damage at key hinge joints is conducted. The simulation results indicate that the proposed method can accurately analyze the fatigue damage of offshore engineering structure caused by the effect of wave load. The present analytical method of fatigue characteristics can be extended on other offshore engineering structures subjected to meta-ocean load. 展开更多
关键词 fatigue characteristics full scale measurement finite element method SYMS
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DIAGNOSTICS OF FATIGUE CRACK IN ULTERIOR PLACES OF LARGER-SCALE OVERLOADED SUPPORTING SHAFT BASED ON TIME SERIES AND NEURAL NETWORKS 被引量:2
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作者 LI Xueiun BIN Guangfu CHU Fulei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2007年第3期79-82,共4页
To improve the diagnosis accuracy and self-adaptability of fatigue crack in ulterior place of the supporting shaft, time series and neural network are attempted to be applied in research on diag-nosing the fatigue cr... To improve the diagnosis accuracy and self-adaptability of fatigue crack in ulterior place of the supporting shaft, time series and neural network are attempted to be applied in research on diag-nosing the fatigue crack’s degree based on analyzing the vibration characteristics of the supporting shaft. By analyzing the characteristic parameter which is easy to be detected from the supporting shaft’s exterior, the time series model parameter which is hypersensitive to the situation of fatigue crack in ulterior place of the supporting shaft is the target input of neural network, and the fatigue crack’s degree value of supporting shaft is the output. The BP network model can be built and net-work can be trained after the structural parameters of network are selected. Furthermore, choosing the other two different group data can test the network. The test result will verify the validity of the BP network model. The result of experiment shows that the method of time series and neural network are effective to diagnose the occurrence and the development of the fatigue crack’s degree in ulterior place of the supporting shaft. 展开更多
关键词 Neural network Time series Larger-scale overloaded Supporting shaft Ulterior place fatigue crack
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Reliability and validity of the Chinese version of the PedsQL Multidimensional Fatigue Scale in children with acute leukemia
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作者 Qimeng Ye Ke Liu +2 位作者 Jun Wang Xiuqing Bu Lili Zhao 《International Journal of Nursing Sciences》 2016年第2期146-152,共7页
Background:The PedsQL Multidimensional Fatigue Scale(PedsQL^(TM)MFS)is widely used to rate fatigue in children living in English-speaking countries.However,insufficient instruments are available to conduct parallel as... Background:The PedsQL Multidimensional Fatigue Scale(PedsQL^(TM)MFS)is widely used to rate fatigue in children living in English-speaking countries.However,insufficient instruments are available to conduct parallel assessment on fatigue in parents and children in China.In this regard,an appropriate measurement method must be developed.Objectives:This study aims to determine the reliability and validity of the Chinese-language PedsQL^(TM)MFS.Methods:Children with cancer(n=125)and their parents were surveyed in Guangzhou,China.The parents of children aged 2e4 years completed the PedsQL^(TM)MFS proxy reports,whereas the other children and their parents completed the questionnaires by themselves.Results:The PedsQL^(TM)MFS-Chinese version demonstrated satisfactory internal consistency reliability(child self-report Cronbach's a=0.87;parent self-report Cronbach's a=0.93).The factor loadings of the items ranged from 0.78 to 0.87 for general fatigue,0.56e0.78 for sleep/rest fatigue,and 0.62e0.89 for cognitive fatigue.Conclusion:This study proves that the PedsQL^(TM)MFS-Chinese version is an effective tool for screening fatigue in Chinese children with cancer. 展开更多
关键词 Acute leukemia CHILDREN fatigue scale RELIABILITY Validity
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Changes in mean cerebral blood flow velocity during cognitive task-induced cerebral fatigue in high performance fighter pilots 被引量:3
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作者 Yongsheng Chen 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第11期1261-1264,共4页
BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJEC... BACKGROUND: Several studies have demonstrated that sustained cognitive tasks can induce cognitive fatigue and that the mean cerebral blood flow velocity changes in some cerebral regions during cerebral fatigue. OBJECTIVE: To dynamically monitor the changes in mean cerebral blood flow velocity in different brain regions of high performance fighter pilots during mental arithmetic tasks and consecutive performance tasks. DESIGN, TIME AND SETTING: The present neurophysiological trial, based on controlled observation, was performed at the Laboratory of Neurophysiology, Institute of Aviation Medicine, Air Force of China between January 2003 and December 2005. PARTICIPANTS: Forty-five males, high performance fighter pilots, averaging (27.6±2.5) years, were recruited for this study. METHODS: The mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery of subjects was dynamically tested using transcranial Doppler during 5- hour mental arithmetic tasks and during 5- hour consecutive performance tasks. The neurobehavioral ability index was analyzed throughout each trial according to the number of correct responses, false responses, and lost responses. Simultaneously, cerebral cognitive fatigue-induced lethargy was assessed by the Stanford Sleepiness Scale. MAIN OUTCOME MEASURES: Changes in mean cerebral blood flow velocity in the anterior cerebral artery, middle cerebral artery, and posterior cerebral artery; neurobehavioral ability index of mental arithmetic and consecutive performance tasks; Stanford Sleepiness Scale scores. RESULTS: During mental arithmetic tasks, the mean cerebral blood flow velocity in the anterior cerebral artery increased during hour 2 and decreased after hour 4. There was no significant change in mean cerebral blood flow velocity in the middle cerebral artery and posterior cerebral artery. During hour 4, cerebral cognitive fatigue was observed and, simultaneously, Stanford Sleepiness Scale scores demonstrated the presence of fatigue. During such a stage, the neurobehavioral ability index decreased, indicating a decline in performance ability. During consecutive performance tasks, the mean cerebral blood flow velocity declined earlier in the posterior cerebral artery compared to the middle cerebral artery. CONCLUSION: Five- hour mental arithmetic tasks have few effects on cerebral functions and do not lead to a significant change in mean cerebral blood flow velocity. Five-hour consecutive performance tasks can induce cerebral cognitive fatigue, and a marked decline in mean cerebral blood flow velocity. 展开更多
关键词 cerebral cognitive fatigue cerebral artery blood velocity neurobehavioral ability index Stanford Sleepiness scale
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Development of a Tool for Assessment of Post-Myocardial Infarction Fatigue 被引量:1
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作者 Eva Brink Ulla Fredriksson-Larsson +2 位作者 Pia Alsén Marianne Lang Christina Cliffordson 《Open Journal of Nursing》 2018年第11期811-822,共12页
Introduction: After treatment for myocardial infarction (MI) quite a few persons will experience different symptoms, including fatigue, during the recovery phase. The aim of the present study was to construct the mult... Introduction: After treatment for myocardial infarction (MI) quite a few persons will experience different symptoms, including fatigue, during the recovery phase. The aim of the present study was to construct the multidimensional Post-Myocardial Infarction Fatigue (PMIF) scale, based on empirical data gathered in coronary heart disease contexts. Methods: The construction of the post-MI fatigue scale was conducted in seven steps, ending in a psychometric evaluation of the internal structure of the scale, using confirmatory factor analysis, as well as testing of convergent and discriminant validity, using correlational analysis, in a sample of 141 persons treated for MI. Results: The results showed that the PMIF scale represents three dimensions: physical, cognitive and emotional fatigue. It was also found that the scale is suitable for summing the items to obtain a total score representing a post-MI global fatigue dimension. Conclusion: The PMIF is a brief and easily completed scale for identifying persons experiencing post-MI fatigue. Early identification of fatigue, together with health behavior support, might prevent progression toward a more severe state of fatigue. 展开更多
关键词 fatigue Myocardial Infarction Psychometric Evaluation scale Development
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Muscle fatigue in women with primary biliary cirrhosis:Spectral analysis of surface electromyography
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作者 Maria Rosa Biagini Alessandro Tozzi +3 位作者 Antonello Grippo Andrea Galli Stefano Milani Aldo Amantini 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第32期5186-5190,共5页
瞄准:与健康题目相比与主要胆汁性肝硬变在病人评估外部易疲性的肌电表明。方法:有没有 comorbidity 的主要胆汁性肝硬变的十六个女人和好久匹配的 13 个健康女人和身体团索引(BMI ) 完成了自我报导的问询表疲劳影响规模。所有题目经... 瞄准:与健康题目相比与主要胆汁性肝硬变在病人评估外部易疲性的肌电表明。方法:有没有 comorbidity 的主要胆汁性肝硬变的十六个女人和好久匹配的 13 个健康女人和身体团索引(BMI ) 完成了自我报导的问询表疲劳影响规模。所有题目经历了对外部易疲性的表面肌电描记法评价。前面的胫骨的肌肉等轴的随意收缩在 80% 最大的自愿的等长收缩为 20 s 被执行。在锻练 electromyographic 信号期间,系列象 electromyographic 信号频率光谱(肌肉易疲性的估计) 的平均数和 median 一样被记录,根意味着平方(中央开车的表达式) 被计算。每个题目执行了试用 two times。EMG 参数被规范的、然后线性的回归被使用,斜坡是计算的。结果:七个病人被使疲劳(中部的疲劳影响规模分数:38,变化:26-66 ) 并且 9 没被使疲劳(中部的疲劳影响规模分数:7,变化:0-17 ) 。最大的自愿的等长收缩在病人是类似的(82, 54-115 N ) 并且控制(87, 74-101 N ) ,并且在有高度的病人(81, 54-115 N ) 并且低疲劳影响规模分数(86, 65-106 N ) 。方形以及频率光谱斜坡吝啬、中部的根平均数与 Mann-Whitney U 测试相比,并且没有有效差量被发现在之间使疲劳并且非使 \O 疲劳的病人和控制。结论:外部易疲性的仪器的证据都不能与主要胆汁性肝硬变而是没有 comorbidity 在女人被发现,建议在如此的病人的那疲劳可能具有中央起源。 展开更多
关键词 肌肉疲劳 胆硬化 光谱分析 肌电图
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Effect of Meridian Massage for Cancer Related Fatigue
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作者 In sook Jeoung Hwa-Seung Yoo 《世界科学技术-中医药现代化》 2008年第4期136-143,116,共9页
Objectives:The purpose of this study is to investigate the effectiveness of meridian massage in lessening the fatigue and improving both physical and mental quality of life of cancer patients.Settings and design:This ... Objectives:The purpose of this study is to investigate the effectiveness of meridian massage in lessening the fatigue and improving both physical and mental quality of life of cancer patients.Settings and design:This study was conducted at the East-West Cancer Center at Daejeon University;Using a single-arm,waiting list and non-treatment control research de- sign,we compared the results of control group and to that of the experimental group.Materials and methods:From July 2,2007 to July 28,2007,eighteen eligible cancer patients were recruited to participate in the experiment.Modified Chalder Fatigue Scale(CFS),Visual Analogue Scale(VAS)and active oxygen level were measured before and after treatment for both control and experimental groups.Lying on their back or stomach inside a room with a temperature of 18-22℃,the pa- tients received 30 minutes of meridian massages mainly around the trapezius muscles 5 times a week. Statistical analysis used:Data analysis was carried out using independent t-test,paired t-test and One-way ANOVA. Results:Data analysis of modified CFS showed statistically significant results for all groups between before and after treat- ment.Within CFS,results of physical and psychological analysis showed significant results for all groups except before and after no treatment and secondary treatment.In the analysis of VAS,the experimental group showed a greater decrease in score compared to that of the control group and the average difference was statistically significant(P<0.05).Although the results were not statistically significant(P>0.05),active oxygen levels for the control group showed little difference before and after no treatment(331.11 and 330.78,respectively)while the experimental group observed a decrease in active oxygen level before and after treatment(327.28 and 314.11,respectively).Conclusion:In conclusion,patients who received meridian massage showed decreased cancer related fatigue scores compared to the control.These results suggest that meridian massage may alleviate cancer-related fatigue and contribute to the improvement in quality of life among cancer patients. 展开更多
关键词 癌症 疲劳 治疗方法 临床分析
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Moroccan Taxi Drivers Fatigue Using Pichot Questionnaire: A Cross-Sectional Survey
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作者 Nadia Benaicha Abdessalam Diarra +3 位作者 Oussmane Desire Diakite Oussamne S.Y Adil Najdi Mohamed AmineBerraho 《Journal of Health Science》 2017年第2期114-120,共7页
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补中益气汤加减联合灵龟八法治疗胃癌放疗后癌性疲乏临床研究 被引量:1
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作者 梁冰 张振 《新中医》 CAS 2024年第1期179-184,共6页
目的:观察补中益气汤加减联合灵龟八法治疗胃癌放疗后癌性疲乏的临床疗效。方法:选择胃癌放疗后癌性疲乏患者84例,按随机数字表法分为对照组和观察组各42例。对照组给予常规对症支持治疗,观察组给予补中益气汤加减联合灵龟八法治疗。2... 目的:观察补中益气汤加减联合灵龟八法治疗胃癌放疗后癌性疲乏的临床疗效。方法:选择胃癌放疗后癌性疲乏患者84例,按随机数字表法分为对照组和观察组各42例。对照组给予常规对症支持治疗,观察组给予补中益气汤加减联合灵龟八法治疗。2组均治疗8周。比较2组临床疗效、中医证候评分、相关癌性疲乏量表评分、生活质量评分、营养状况及炎症因子水平,并统计恶心呕吐分级情况。结果:观察组总有效率为92.86%,高于对照组78.57%(P<0.05)。治疗后,2组纳差乏力、面色萎黄、头晕气短、肢体倦怠评分均较治疗前降低(P<0.05),且观察组各项评分低于对照组(P<0.05)。治疗后,2组简短疲劳量表(BFI-C)、临床虚弱量表(CFS)评分较治疗前降低,Karnofsky功能状态评分、日常生活活动能力(ADL)评分较治疗前升高(P<0.05);且观察组BFI-C、CFS评分低于对照组,Karnofsky功能状态评分、ADL评分高于对照组(P<0.05)。治疗后,2组血清前白蛋白、白蛋白、转铁蛋白水平较治疗前升高,血清白细胞介素-6(IL-6)、白细胞介素-1β(IL-1β)、肿瘤坏死因子-α(TNF-α)水平较治疗前降低(P<0.05);且观察组血清前白蛋白、白蛋白、转铁蛋白水平高于对照组,血清IL-6、IL-1β、TNF-α水平低于对照组(P<0.05)。观察组呕吐总发生率为47.62%,低于对照组73.81%(P<0.05)。结论:补中益气汤加减联合灵龟八法治疗胃癌放疗后癌性疲乏患者临床疗效显著。 展开更多
关键词 胃癌放疗后 癌性疲乏 补中益气汤 灵龟八法 癌性疲乏量表 生活质量 细胞因子
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多尺度聚丙烯纤维混凝土弯曲疲劳寿命试验及数值模拟
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作者 梁宁慧 毛金旺 +2 位作者 游秀菲 刘新荣 周侃 《材料导报》 EI CAS CSCD 北大核心 2024年第4期95-102,共8页
为研究多尺度聚丙烯纤维混凝土的弯曲疲劳性能,开展基准混凝土、聚丙烯粗纤维混凝土及多尺度聚丙烯纤维混凝土的静载试验及不同应力水平(0.75、0.80、0.85)下的弯曲疲劳试验,建立弯曲疲劳寿命方程,并结合ABAQUS与FE-SAFE软件建立纤维混... 为研究多尺度聚丙烯纤维混凝土的弯曲疲劳性能,开展基准混凝土、聚丙烯粗纤维混凝土及多尺度聚丙烯纤维混凝土的静载试验及不同应力水平(0.75、0.80、0.85)下的弯曲疲劳试验,建立弯曲疲劳寿命方程,并结合ABAQUS与FE-SAFE软件建立纤维混凝土梁的三点弯曲疲劳有限元模型。结果表明:聚丙烯纤维的掺入,尤其是多尺度聚丙烯纤维混掺显著增强了混凝土基体的抗折、抗疲劳性能。双对数lgS-lgN疲劳方程能够较好地描述多尺度聚丙烯纤维混凝土的应力水平与疲劳寿命的相关性,使用lgS-lgN疲劳方程计算得到200万次循环荷载作用下多尺度聚丙烯纤维混凝土的疲劳强度最高,为3.91 MPa。三组试件疲劳寿命的数值模型预测值均介于实测疲劳寿命的最大值与最小值之间,并接近于疲劳寿命平均值,该模型为多尺度聚丙烯纤维混凝土的疲劳寿命预测提供了理论依据。 展开更多
关键词 多尺度 聚丙烯纤维混凝土 弯曲疲劳 疲劳寿命预测 数值模拟
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金属疲劳损伤全寿命过程及工程应用综述
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作者 彭艳 张伟 +2 位作者 李如俊 李玉雪 邵为义 《塑性工程学报》 CAS CSCD 北大核心 2024年第4期117-130,共14页
金属疲劳损伤过程复杂,不同载荷类型与服役环境下金属疲劳损伤机理、变形特性和破坏模式存在较大差异。将疲劳损伤全寿命过程按照循环寿命周次划分为超高周、高周、低周和裂纹扩展4个类别,根据变形响应特性和变形机理特征阐述了各类别... 金属疲劳损伤过程复杂,不同载荷类型与服役环境下金属疲劳损伤机理、变形特性和破坏模式存在较大差异。将疲劳损伤全寿命过程按照循环寿命周次划分为超高周、高周、低周和裂纹扩展4个类别,根据变形响应特性和变形机理特征阐述了各类别疲劳损伤的研究现状及发展趋势,涉及宏观尺度、微细观尺度和宏细微观多尺度理论体系。同时结合工程实际案例,以轧辊和燕尾榫作为代表性构件,分析其疲劳损伤行为与影响因素,探讨了目前疲劳理论在工程实践中的应用及挑战,旨在为金属疲劳损伤全寿命理论体系的完善和关键部件健康质量管控提供理论依据和技术指导。 展开更多
关键词 金属疲劳 全寿命 多尺度 工程实践
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沥青混合料弯曲疲劳损伤强度的多尺度研究
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作者 李友云 王斌 +1 位作者 高英力 吕琰 《河南理工大学学报(自然科学版)》 CAS 北大核心 2024年第3期181-191,共11页
目的为了验证多尺度数值试验模拟方法在预测沥青混合料半圆弯曲试验疲劳损伤过程中弯拉强度参数变化规律的有效性问题。方法基于多尺度算法思想和半圆弯曲试验,通过对沥青混合料试件进行细观结构分析,得到内部集料颗粒的几何特征分布规... 目的为了验证多尺度数值试验模拟方法在预测沥青混合料半圆弯曲试验疲劳损伤过程中弯拉强度参数变化规律的有效性问题。方法基于多尺度算法思想和半圆弯曲试验,通过对沥青混合料试件进行细观结构分析,得到内部集料颗粒的几何特征分布规律;在此基础上,对沥青混合料划分5个微观区域尺度,并构建相应尺度下半圆弯曲试件的有限元(FEM)数值模型,结合多尺度迭代运算来预测各级沥青混合料计算在0%Nf,20%Nf,50%Nf,65%Nf,80%Nf(Nf为疲劳寿命)不同半圆弯拉疲劳损伤程度下的弯拉强度。将室内半圆弯曲试验获得不同粒径的沥青混合料的弯拉强度参数作为宏观验证试验,与通过多尺度算法数值模拟试验所得的弯拉强度进行对比分析研究。结果结果表明:在沥青混合料的疲劳损伤过程中,前期材料的抗弯拉强度衰减速率较为缓慢,当在中后期时,抗弯拉强度进入了急剧衰减阶段,多尺度数值模拟试验与室内试验得到的衰减规律相吻合,且弯拉强度相对误差的绝对值控制在8%以内。结论多尺度数值模拟用于预测疲劳过程中沥青混合料的抗弯拉强度参数是有效的,该算法可以为类似的实际工程提供一定的参考意义。 展开更多
关键词 沥青混合料 半圆弯曲试验 细观结构 疲劳性能 刚度参数 多尺度预测
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全机疲劳试验几个问题的探讨
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作者 张立新 《航空工程进展》 CSCD 2024年第4期10-15,26,共7页
全机疲劳试验是规范要求的保障飞机结构完整性以及满足适航要求的大型、复杂以及持续时间长的地面验证试验。全机疲劳试验的几个重要问题,例如试验目的、载荷谱、持续时间和分散系数等,是飞机设计师/工程师非常关注和充分讨论的问题,其... 全机疲劳试验是规范要求的保障飞机结构完整性以及满足适航要求的大型、复杂以及持续时间长的地面验证试验。全机疲劳试验的几个重要问题,例如试验目的、载荷谱、持续时间和分散系数等,是飞机设计师/工程师非常关注和充分讨论的问题,其中的分散系数也是研究者研究较多的问题之一。针对近年来完成的多个飞机型号的全机疲劳试验,本文介绍了对上述几个问题的研究和认识,对比了国内外5种型号战斗机的疲劳设计与全机疲劳试验情况,提出了关于全机疲劳试验的工程实用的一些建议。本文的研究可以为其他飞机全机疲劳试验提供有益的参考。 展开更多
关键词 全机疲劳试验 耐久性 损伤容限 载荷谱 持续时间 分散系数
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正交异性钢-钢纤维混凝土组合桥面板疲劳极限状态研究
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作者 叶华文 潘威洲 +2 位作者 何建希 叶杨帆 邓雪峰 《桥梁建设》 EI CSCD 北大核心 2024年第4期46-52,共7页
为了解正交异性钢-钢纤维混凝土(Steel Fiber Reinforced Concrete,SFRC)组合桥面板的疲劳性能及失效机理,以川南城际铁路临港长江大桥为背景,设计、制作正交异性钢-SFRC组合桥面板足尺模型进行疲劳试验,采用ANSYS软件建立试件有限元模... 为了解正交异性钢-钢纤维混凝土(Steel Fiber Reinforced Concrete,SFRC)组合桥面板的疲劳性能及失效机理,以川南城际铁路临港长江大桥为背景,设计、制作正交异性钢-SFRC组合桥面板足尺模型进行疲劳试验,采用ANSYS软件建立试件有限元模型,研究关键细节的疲劳应力和开裂等情况。基于有限元模型,分析不同设计参数(钢顶板厚度、栓钉布置、SFRC抗拉强度及层厚)下组合桥面板疲劳极限状态的失效模式,并提出了主要控制参数取值建议。结果表明:200万次疲劳加载后足尺模型的实测最大裂缝宽度为0.136 mm,出现在SFRC层上缘,钢结构未开裂,组合桥面板疲劳性能良好;组合桥面板疲劳极限状态主要由SFRC层开裂控制,钢顶板厚度、栓钉布置对组合桥面板疲劳性能的影响较小,SFRC抗拉强度和层厚对组合桥面板疲劳性能影响较大,为主要控制参数;在常规正交异性钢桥面板上铺设薄层(厚度不超过50 mm)SFRC时,SFRC抗拉强度不应小于5 MPa,在常规正交异性钢桥面板上铺设普通SFRC(钢纤维体积含量不高于1%,抗拉强度不高于3 MPa)时,SFRC层厚不宜低于100 mm。 展开更多
关键词 组合桥面板 正交异性钢板 钢纤维混凝土 疲劳失效模式 参数分析 足尺模型试验 有限元法
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新型钛合金焊接结构疲劳裂纹扩展速率试验研究
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作者 袁青松 王珂 +3 位作者 李永正 张宇阳 李金鹏 雷银慧 《舰船科学技术》 北大核心 2024年第5期43-47,共5页
为了研究尺度效应及热处理工艺对新型钛合金材料疲劳性能的影响,本文对新型钛合金母材及焊接结构在不同尺度效应和热处理工艺下的力学性能和疲劳性能开展试验,分析尺度效应和热处理工艺对新型钛合金材料疲劳性能的影响规律。研究结果表... 为了研究尺度效应及热处理工艺对新型钛合金材料疲劳性能的影响,本文对新型钛合金母材及焊接结构在不同尺度效应和热处理工艺下的力学性能和疲劳性能开展试验,分析尺度效应和热处理工艺对新型钛合金材料疲劳性能的影响规律。研究结果表明,仅经过低温热处理的新型钛合金焊接结构疲劳寿命要超过经过高温-低温热处理后的焊接接头近1.53倍;尺度效应对焊接结构的力学性能影响较大,对母材影响较小;随着尺度增大新型钛合金的裂纹扩展寿命增大,但裂纹扩展速率并无明显变化。 展开更多
关键词 新型钛合金 尺度效应 热处理工艺 疲劳性能
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考虑车桥耦合及环境腐蚀的铁路钢桥疲劳分析
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作者 胡春建 孙洪斌 +4 位作者 卢大治 冯乾朔 余玉洁 朱志辉 王海波 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2024年第3期1256-1265,共10页
耐候钢通过改变合金元素以在其表面形成致密保护性防锈层因而具备良好的耐大气腐蚀性能,因此其在免涂装使用中为带锈工作,应用于公路和铁路桥梁中时可能存在腐蚀和疲劳耦合损伤问题。基于潍莱铁路线一座全焊接免涂装耐候钢桥开展列车动... 耐候钢通过改变合金元素以在其表面形成致密保护性防锈层因而具备良好的耐大气腐蚀性能,因此其在免涂装使用中为带锈工作,应用于公路和铁路桥梁中时可能存在腐蚀和疲劳耦合损伤问题。基于潍莱铁路线一座全焊接免涂装耐候钢桥开展列车动力作用下的关键构件和焊接节点疲劳损伤分析,并进行考虑腐蚀劣化影响下的疲劳寿命评估。基于列车-轨道-桥梁耦合系统模型研究在高速列车动力荷载下桥梁主桁关键构件动力响应并得到结构中最不利构件位置,分析关键构件在列车通行振动效应下的疲劳损伤度;结合考虑局部节点板精细化的多尺度耦合有限元模型,考虑轨道不平顺和列车运行速度的影响,得到桥梁节点板在不同速度下的疲劳损伤度;考虑环境腐蚀对桥梁疲劳寿命的影响,结合桥梁列车年运营量进行腐蚀环境下桥梁关键杆件和节点的疲劳使用寿命评估。研究结果表明:铁路钢桁梁桥在列车动力作用下不同构件的疲劳损伤不同,刚度较小以及应力响应影响线较短的构件疲劳损伤度更大,其中疲劳损伤度由大到小依次为节点横梁、腹杆、下弦杆、上弦杆。轨道不平顺和列车运行速度对桥梁节点板应力响应最大值影响并不显著,列车运行速度为120 km/h时与所分析桥梁共振更明显。环境腐蚀会降低铁路桥梁疲劳寿命,且对桥梁不同构件寿命影响程度不同。研究成果可为同类型铁路钢桁梁桥在腐蚀环境下的疲劳寿命评估和设计提供参考。 展开更多
关键词 铁路钢桁梁桥 车桥耦合系统 多尺度有限元模型 应力响应 疲劳损伤分析 腐蚀疲劳寿命评估
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多尺度纤维对水泥基复合材料性能的影响
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作者 卫颖颖 刘超群 罗林 《深圳大学学报(理工版)》 CAS CSCD 北大核心 2024年第2期145-151,共7页
为准确掌握多尺度纤维对水泥基复合材料的性能影响规律,以碳酸钙晶须(calcium carbonate whisker,CW)纤维、钢纤维及聚乙烯醇(polyvinyl alcohol,PVA)纤维为基础,构建多尺度纤维水泥基复合材料,并在不同配合比条件下,通过流动性试验、... 为准确掌握多尺度纤维对水泥基复合材料的性能影响规律,以碳酸钙晶须(calcium carbonate whisker,CW)纤维、钢纤维及聚乙烯醇(polyvinyl alcohol,PVA)纤维为基础,构建多尺度纤维水泥基复合材料,并在不同配合比条件下,通过流动性试验、单轴受压试验、三点弯曲缺口试验和叠加试验(overlay test,OT),研究多尺度纤维对水泥基复合材料力学性能、断裂性能及疲劳性能的影响规律.结果表明,多尺度纤维对水泥基复合材料的力学性能及断裂性能均具显著影响,在力学性能方面,多尺度纤维能较大程度上减弱水泥基复合材料的流动扩展度,并提高轴心抗压强度和弯曲抗拉强度;在断裂性能研究方面,单掺纤维组和混杂纤维组均能不同程度上提高水泥基复合材料的断裂性能.其中,对失稳断裂韧度和黏聚韧度的提升规律较为一致,在断裂性能指标的提升幅度上,黏聚韧度>失稳断裂韧度>起裂断裂韧度;CW纤维、钢纤维及PVA纤维的体积分数分别为0.50%、0.75%和0.25%时,水泥基复合材料的疲劳性能相对最优.研究成果可为水泥基复合材料的工程应用提供理论依据. 展开更多
关键词 复合材料 多尺度纤维 试验设计 力学性能 断裂性能 疲劳性能
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冠心病病人疲乏评估工具的研究进展
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作者 李嘉惠 周欣 +2 位作者 邢盈 罗慧怡 兰艳莉 《全科护理》 2024年第2期283-287,共5页
从单维度量表和多维度量表两个方面综述目前国内外应用于冠心病病人疲乏的评估工具,阐述各个量表的评估内容、信效度、应用情况及优缺点,以期为临床医务人员选择合适的评估工具和开发适用我国本土化的冠心病病人疲乏评估工具提供参考。
关键词 冠心病 疲乏 量表 综述
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四君子汤治疗脾虚型慢性疲劳综合征临床研究
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作者 潘泗红 张振贤 《新中医》 CAS 2024年第6期23-28,共6页
目的:观察四君子汤治疗脾虚型慢性疲劳综合征的临床疗效。方法:选取脾虚型慢性疲劳综合征患者72例作为研究对象,采用随机数字表法分为对照组和试验组各36例。2组均提供健康宣教,试验组采用四君子汤颗粒剂治疗,对照组给予安慰剂颗粒干预... 目的:观察四君子汤治疗脾虚型慢性疲劳综合征的临床疗效。方法:选取脾虚型慢性疲劳综合征患者72例作为研究对象,采用随机数字表法分为对照组和试验组各36例。2组均提供健康宣教,试验组采用四君子汤颗粒剂治疗,对照组给予安慰剂颗粒干预。比较2组临床疗效和安全性,以及治疗前后疲劳症状评分、中医证候评分、疲劳度[Chalder疲劳问卷评分表(Chalder)]评分、SF-36健康调查量表中文版(SF-36)评分、五水平五维健康量表(EQ-5D-5L)评分及血清氧化应激指标[皮质醇稳定蛋白(CORT)、丙二醛(MDA)、超氧化物歧化酶(SOD)及谷胱甘肽过氧化物酶(GSH-PX)]水平。结果:治疗后,试验组总有效率为94.44%,对照组为77.78%,2组比较,差异有统计学意义(P<0.05)。治疗1、2个月后,2组睡眠障碍、紧张焦虑和记忆力减退等疲劳症状评分均较治疗前降低(P<0.05),且试验组3项评分在相同时间点均低于对照组(P<0.05)。治疗1、2个月后,2组中医证候评分、Chalder评分均较治疗前降低(P<0.05),且试验组中医证候评分、Chalder评分在相同时间点均低于对照组(P<0.05)。治疗1、2个月后,2组SF-36、EQ-VAS评分评分均较治疗前升高(P<0.05);且试验组2项评分在相同时间点均高于对照组(P<0.05)。治疗1、2个月后,2组血清中CORT、SOD及GSH-PX水平均较治疗前升高(P<0.05),MDA水平均较治疗前降低(P<0.05),且试验组CORT、SOD及GSH-PX水平在相同时间点均高于对照组(P<0.05),MDA水平在相同时间点低于对照组(P<0.05)。结论:四君子汤治疗脾虚型慢性疲劳综合征疗效显著,可改善脾虚症状,提高患者生活质量,改善氧化应激反应,且安全性较好。 展开更多
关键词 慢性疲劳综合征 脾虚型 四君子汤颗粒剂 Chalder疲劳问卷评分表 氧化应激
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