作业疲劳的生理心理学分析

本文从生理心理学的角度分析了疲劳的特点、表现及其对安全生产的影响，以及疲劳产生的原因，了减轻疲劳的措施，特别指出了在机械化和自动化水平不断提高的今天减轻心理疲劳的重要意义，并运用疲劳的动机理论说明了作业者动机水平，可达到减轻心里疲劳，促进安全生产的目的。     

重轨疲劳试验机在线监测软件开发

从计算机控制软件的原理和设计等方面对ZDM200tpw疲劳试验机在线监测进行了阐述,改造后该疲劳试验机在试验精度、准确度等方面都有了保障,极大地方便了试验人员.     

浅谈高校对高血压病与心率变异82例临床分析

为了进一步了解心率变异在高血压病患者与正常人两者之间的差异,本研究选择高血压患者82例为观察组,选择健康者(均为健康体检者)68例作为对照组.进行24h动态心电图监测和心率变异分析.结果显示高血压组的各时域和频域指标均较对照组明显减低,具有显著性意义.心率变异分析是一简便、易行、无创、可重复检查、可作为目前判断自主神经活动和均衡的最好方法之一.     

基于光电容积脉搏波的有限空间生理疲劳测量

通过有限空间100 min极限载人实验,提出了基于光电容积脉搏波(PPG)的客观疲劳测量方法并开发了光电容积脉搏波信号特征参数提取算法用来掌握生理疲劳的血液动力学与循环系统变化特征.研究结果表明,人体出现生理疲劳时,光电容积脉搏波信号平均周期显著大于未疲劳状态(p<0.001),血管阻力增大,每搏射血量明显下降;计算了未疲劳与疲劳状态下光电容积脉搏波信号的两种复杂度(KC复杂度和高阶KC复杂度)发现,两种复杂度计算结果一致,均为未疲劳时波形比疲劳时波形更平稳.因此表明光电容积脉搏波信号能够捕捉到疲劳状态的生理变化,解决了生理疲劳的客观测量与快速判断问题.     

ZDM200疲劳试验机监测系统研制

通过给ZDM200疲劳试验机加装计算机监测系统,使重轨实物疲劳试验数据更加精确,且完全满足重轨实物疲劳试验标准的要求.     

基于声发射测试的钢丝疲劳损伤过程

应用声发射（ＡＥ）技术对制绳钢丝疲劳损伤过程进行动态监测。结果表明疲劳伤普遍产生于钢丝长度方向上的不同部位,所有部位的损伤经过钢丝初始塑性变形阶段之后都同时进入一个长期的慢速发展阶段,在此期间主导裂纹形成,由于主民裂纹以快速扩展方式发展,因而疲劳寿命主要由主裂纹孕育及生成期构成。     

疲劳失效机理及热轧H型钢疲劳断口分析

介绍了疲劳断口类型、形貌及形成机理,并对热轧H型钢疲劳断口进行了分析,为今后型钢产品疲劳研究奠定基础。     

基于声发射监测的316LN不锈钢的疲劳损伤评价

疲劳裂纹的萌生与扩展容易导致压力容器及管道的严重疲劳失效.因此就设备的安全可靠性而言,非常有必要对疲劳裂纹扩展过程进行监测,并对疲劳损伤程度进行评估.本文针对316LN不锈钢材料进行疲劳实验研究,利用直流电位法测量实验中的裂纹长度,得到了材料的疲劳裂纹扩展曲线.利用声发射技术对疲劳裂纹扩展过程进行监测,通过声发射多参数分析对疲劳损伤状态进行评价,同时建立了声发射参数与线弹性断裂力学参数之间的关系,并进行寿命预测.研究表明:声发射能够对316LN不锈钢的疲劳裂纹损伤进行有效评估,声发射累积参数如累积计数、累积能量和累积幅值曲线上的转折点标志着疲劳裂纹进入快速扩展阶段,这可以为工程人员提供失效预警;声发射波形和频谱分析表明,噪声信号的幅值较小且信号持续时间较长,信号包含的频率成分比较复杂,而裂纹扩展信号是突发型信号,衰减较快,信号频率主要集中在80~170 kHz范围内;声发射计数率、能量率和幅值率与应力强度因子幅度以及疲劳裂纹扩展速率之间呈线性关系,裂纹长度预测结果与实测值接近.本研究工作对于工程结构的疲劳失效预警和剩余寿命预测具有重要意义.     

老年冠心病69例心率震荡分析及临床意义研究

心率震荡(HRT)是指单个室性早搏后出现的窦性心律先加速随后减速的现象,是心脏自主神经对室性早搏出现的快速调节反应,反映了窦房结的双相变时功能.是一项新的简单、实用、无创的心脏事件预测指标.我们对60例老年冠心病患者的HRT指标进行分析并随访观察,以探讨其特点及临床意义.     

基于疲劳累积损伤的X80钢疲劳裂纹寿命研究

为了更准确地预测工程管道在随机载荷作用下的疲劳寿命,要考虑载荷顺序与载荷间相互作用对寿命预测的影响。基于Manson-Halford模型和Corten-Dolan模型,建立了既考虑荷载顺序和荷载间相互作用,又考虑疲劳极限附近荷载的疲劳累积损伤因素。通过该模型可以计算管道在随机载荷下的疲劳寿命,为随机载荷谱下的寿命预测提供了理论依据。将该模型的计算结果与Miner法则、Manson-Halford模型和Corten-Dolan模型的计算结果进行比较,表明所建立的疲劳损伤模型可以合理地预测零件的疲劳寿命。通过算例验证进一步证明了所提模型的准确性和可靠性。     

Social interaction moderates the relationship between depressive mood and heart rate variability: Evidence from an ambulatory monitoring study.

Objective: There is considerable evidence that depressive mood is related to lower parasympathetic control of the heart, thus increasing cardiovascular risk. However, little is known about social factors (e.g., social affiliation) that might moderate this relationship. Design: The authors examined whether cardiac autonomic control in healthy individuals with depressive symptoms could be altered by social interaction. Therefore, the authors conducted a 22-hr ambulatory monitoring study with a sample of 63 adults. Main Outcome Measures: Depression was assessed by questionnaire. Heart rate, heart rate variability (HRV), physical activity, and negative affect were recorded throughout one day via portable monitoring devices. Results and Conclusion: Multilevel analyses revealed that depression was related to elevated negative affect and higher heart rate throughout the day. Moreover, there was a tendency toward lower HRV in individuals with higher depression scores. This association, however, was moderated by social context. When depressive participants were alone they evidenced lower HRV and higher negative affect, but not when they were engaged in social interactions with a partner, family members, or friends. These findings suggest that the relation between depression and cardiac autonomic control could be altered by social interaction, thus possibly buffering adverse health effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Infant physiological regulation and maternal risks as predictors of dyadic interaction trajectories in families with a preterm infant.

This longitudinal study examined predictors of rates of growth in dyadic interaction quality in children born preterm who did not experience significant neurological findings during neonatal intensive care unit (NICU) hospitalization. Multiple methods were used to collect data from 120 preterm infants (48% girls, 52% boys) and their mothers. Infant heart rate variability (HRV), gestational age, neonatal health, feeding route, and maternal socioeconomic (SES) risks were assessed at NICU discharge (mean of 36 weeks postconception). Mother–child interactions were observed at 4, 9, 16, and 24 months postterm and analyzed with hierarchical linear modeling. On average, children's quality of play, interest, and attention increased over time while their dysregulation and irritability decreased, whereas average maternal positive affect and involvement declined in quality (ps     

Heart rate variability as an index of regulated emotional responding.

The study of individual differences in emotional responding can provide considerable insight into interpersonal dynamics and the etiology of psychopathology. Heart rate variability (HRV) analysis is emerging as an objective measure of regulated emotional responding (generating emotional responses of appropriate timing and magnitude). This review provides a theoretical and empirical rationale for the use of HRV as an index of individual differences in regulated emotional responding. Two major theoretical frameworks that articulate the role of HRV in emotional responding are presented, and relevant empirical literature is reviewed. The case is made that HRV is an accessible research tool that can increase the understanding of emotion in social and psychopathological processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Neuroticism's importance in understanding the daily life correlates of heart rate variability.

Individual differences in high-frequency heart rate variability (HRV) have been conceptualized in terms of a greater capacity to self-regulate problematic outcomes, but have also been conceptualized in terms of greater moment-to-moment flexibility. From a self-regulation perspective, higher HRV should be inversely correlated with trait neuroticism and problematic daily outcomes. From a flexibility perspective, high HRV should result in more state-like functioning—that is, functioning that is more contextual and less trait-like in nature. In the latter case, HRV and trait neuroticism may interact to predict problematic outcomes such that neuroticism should be a less consequential predictor at higher levels of HRV. The flexibility perspective was systematically supported in a daily experience-sampling protocol. Implications focus on theories of neuroticism and HRV. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Resting respiratory sinus arrhythmia is associated with tonic positive emotionality.

Resting respiratory sinus arrhythmia (RSAREST) indexes important aspects of individual differences in emotionality. In the present investigation, the authors address whether RSAREST is associated with tonic positive or negative emotionality, and whether RSAREST relates to phasic emotional responding to discrete positive emotion-eliciting stimuli. Across an 8-month, multiassessment study of first-year university students (n = 80), individual differences in RSAREST were associated with positive but not negative tonic emotionality, assessed at the level of personality traits, long-term moods, the disposition toward optimism, and baseline reports of current emotional states. RSAREST was not related to increased positive emotion, or stimulus-specific emotion, in response to compassion-, awe-, or pride-inducing stimuli. These findings suggest that resting RSA indexes aspects of a person's tonic positive emotionality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Worried Mind: Autonomic and Prefrontal Activation During Worrying.

To study the psychophysiological correlates of worrying, the authors recorded heart rate, respiratory sinus arrhythmia (RSA), skin conductance level, and alpha electroencephalographic asymmetry in healthy males during baseline, relaxation, worry induction, and anticipation of an impromptu speech task. Compared with baseline, relaxation, and anticipation, worrying was associated with greater heart rate and lower RSA. Worrying was further characterized by higher skin conductance levels compared with baseline but lower levels than during anticipation. Finally, worrying was associated with relatively greater left frontal activity compared with anticipation. Trait public speaking anxiety was positively correlated with left frontal activity during worrying. These results support the notion that worrying is a unique emotional state that is different from fearful anticipation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Heart rate variability, the autonomic nervous system, and neuroeconomic experiments.

Measuring the activity of the autonomic nervous system may yield insights into individual stress levels. One small, nonintrusive instrument for collecting such data is a high-resolution heart rate monitor that allows measurement of heart rate variability (HRV). This complements brain-scanning methods and increases the number of participants that can be studied simultaneously. Combining HRV data with recorded data on the decisions made in experimental games throws light on how different individuals react in (economic) decision-making situations. This article therefore introduces the HRV measurement method and, using data from an ultimatum bargaining experiment in a laboratory environment, illustrates its application in experimental economic research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The effect of category variability in perceptual categorization.

Exemplar and distributional accounts of categorization make differing predictions for the classification of a critical exemplar precisely halfway between the nearest exemplars of 2 categories differing in variability. Under standard conditions of sequential presentation, the critical exemplar was classified into the most similar, least variable category, consistent with an exemplar account. However, if the difference in variability is made more salient, then the same exemplar is classified into the more variable, most likely category, consistent with a distributional account. This suggests that participants may be strategic in their use of either strategy. However, when the relative variability of 2 categories was manipulated, participants showed changes in the classification of intermediate exemplars that neither approach could account for. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of two yoga based relaxation techniques on heart rate variability (HRV).

Heart rate variability (HRV) was studied in cyclic meditation (CM) and supine rest (SR). CM included yoga postures followed by guided relaxation. Forty-two male volunteers were assessed in CM and SR sessions of 35 minutes, where CM or SR practice was preceded and followed by 5 minutes of SR. During the yoga postures of CM and after CM, low frequency power and the low frequency to high frequency power ratio decreased, whereas high frequency power increased. Heart rate increased during the yoga postures and decreased in guided relaxation and after CM. There was no change in SR. Hence, it appeared that predominantly sympathetic activation occurred in the yoga posture phases of CM while parasympathetic dominance increased after CM. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Finding groups using model-based cluster analysis: Heterogeneous emotional self-regulatory processes and heavy alcohol use risk.

Model-based cluster analysis is a new clustering procedure to investigate population heterogeneity utilizing finite mixture multivariate normal densities. It is an inferentially based, statistically principled procedure that allows comparison of nonnested models using the Bayesian information criterion to compare multiple models and identify the optimum number of clusters. The current study clustered 36 young men and women on the basis of their baseline heart rate and heart rate variability (HRV), chronic alcohol use, and reasons for drinking. Two cluster groups were identified and labeled the high alcohol risk and normative groups. Compared to the normative group, individuals in the high alcohol risk group had higher levels of alcohol use and more strongly endorsed disinhibition and suppression reasons for use. The high alcohol risk group showed significant HRV changes in response to positive and negative emotional and appetitive picture cues, compared to neutral cues. In contrast, the normative group showed a significant HRV change only to negative cues. Findings suggest that individuals with autonomic self-regulatory difficulties may be more susceptible to heavy alcohol use and use of alcohol for emotional regulation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)