称重油缸失效原因分析与改进

通过对称重油缸的工作原理和失效方式的分析,得出造成油缸失效的几种原因,进而针对性地提出了解决油缸失效的方法。     

螺杆钻具失效的原因分析及预防措施

随着螺杆钻具的广泛使用,螺杆钻具失效时有发生.通过对近几年对螺杆钻具使用情况的跟踪,对失效情况的统计以及对失效螺杆的解剖分析得出了传动轴折断,旁通阀刺漏、定子脱胶、传动轴卡死.丝扣脱扣等几种常见失效形式,总结出了利用各种钻井参数的变化来判断螺杆在井下的工作状态,通过进一步推广判断和预防措施促进了螺杆钻具的正确使用,减少了螺杆钻具失效的发生,螺杆钻具的使用寿命逐年延长.     

高线碳化钨辊失效原因分析及改进

针对天铁棒线厂1#、2#线碳化钨辊的失效现象进行了分析,总结出碳化钨辊失效的8种主要形式,找出了8种碳化钨辊失效产生的原因,通过制定改进措施,减少了碳化钨辊失效的几率,延长了碳化钨辊的使用寿命,降低了生产成本,提高了经济效益.     

失效分析—技术标准—经济索赔

1前言失效分析一般是指对失效零（器）件或产品进行分析，鉴别其失效模式和失效机理，找出失效原因，叫作失效分析。失效原因找出后，其目的，一是针对原因找出改进的方法和措施．二是在社会主义市场经济和法制逐步健全的情况下．确定造成经济损失的责任者．进而进行经济索赔。失效分析技术一般括有化学成分分析、金相试验（含低倍和高信两种试验）、力学性能试验、电镜分析和无损检测等内容。本文中失效分析的零件，括有运行后和运行前两种情况，定义范围较广。读过一些有关失效分析的论文，有些论文中的一些论据，理由不够充分，有的与技…     

金属材料失效浅析

从金属材料失效的定义出发,研究了断裂、磨损、腐蚀三种主要的金属材料失效形式,分析其形成原因及特点,探讨如何预防常见的金属材料失效。     

轧辊失效方式及其原因分析

介绍了轧辊存在剥落、断裂、裂纹等几种失效方式,并重点分析了轧辊剥落和断裂产生的机理,为分析生产实践中轧辊失效原因和采取相应改进措施以提高轧辊使用寿命提供了依据。     

域名服务对Unix系统性能的影响

本文描述了域名服务失效对Unxi主机性能影响的过程,对问题产生的原因及解决进行分析。从解决方法中选择最优。从而完整的陈述了域名失效对Unix主机性能的影响以及几种简便的解决方法.     

H型钢精轧辊的失效分析及预防措施

介绍了国内某钢厂H型钢精轧机水平轧辊存在磨损、裂纹、剥落和断裂等几种失效形式,分析了失效形式产生的原因,并对车间现有轧辊提出相应的改进措施,为后续提高轧辊的使用寿命提供了依据。     

高压空气环境下钨电极失效的研究

在模拟试验舱中进行了高压TIG焊试验,钨极的失效形式主要有烧蚀、钨极尖端粘上金属、钨极熔化3种形式,烧蚀占总失效的90%,钨极尖端粘上金属占到9%,钨极熔化占到1%;给出了钨极失效的几何判据。对钨极凸缘形成机理进行了研究,研究表明,凸缘是电极尖端温度合适的C粗糙区内,钨重结晶和钨的氧化物分解、沉积共同作用的结果。分析了影响高压焊接钨极失效的因素,建立了高压TIG焊钨极失效的故障树,对故障树进行了定性和定量分析,找出它的最小割集,计算出事件的结构重要度系数。在此基础上,提出了防止钨极失效的措施。     

浅谈域名服务对Unix系统性能的影响

本文描述了域名服务失效对Unxi主机性能影响的过程,对问题产生的原因进行分析,井根据实际需求从解决方法中选择最优,从而从应用角度陈述了域名失效对Unix主机性能的影响以及几种简便的解决方法。     

Dynamic effects of self-efficacy on smoking lapses and relapse among adolescents.

Objective: The present study examined whether dynamic day-to-day variations in self-efficacy predicted success in quit attempts among daily smoking adolescents. Design: A sample of 149 adolescents recorded their smoking and self-efficacy three times per day during 1 week prior to and 3 weeks after a quit attempt. Main Outcome Measures: The first lapse, second lapse, and relapse after at least 24 hours of abstinence from smoking were the main outcome measures. Results: Self-efficacy was relatively high and moderately variable prior to the first lapse, but decreased and became more variable thereafter. Lower self-efficacy as measured at the lapse assessment significantly increased the risk that a second lapse and relapse would occur. Individual differences in baseline self-efficacy did not predict any of the treatment outcomes. The time-varying analyses, however, showed that lower self-efficacy on a given day predicted the first lapse, the second lapse, and relapse on the succeeding day. Daily concomitant smoking (any smoking on the preceding day) was not significantly related to relapse. Conclusion: The present results emphasize the importance of self-efficacy among adolescents in cessation and highlight the need for dynamic formulations and assessments of adolescents' self-efficacy and relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Progression from a smoking lapse to relapse: Prediction from abstinence violation effects, nicotine dependence, and lapse characteristics.

Determinants of progression from an initial smoking lapse to relapse, using prospective data from 133 participants were examined. Participants used palm-top computers to record their first lapse, and their reaction to it, within minutes of the event, and were followed for 3 months to assess subsequent smoking. Indicators of the Abstinence Violation Effect—self-efficacy, attributions, and affective reactions to the lapse—generally failed to predict progression to relapse, but participants who felt like giving up after the first lapse progressed more rapidly to a second lapse. Participants who attempted restorative coping were less likely to progress to another lapse on the same day. Those whose lapses were triggered by stress progressed more quickly, whereas those triggered by eating and drinking or accompanied by alcohol consumption progressed more slowly. More nicotine-dependent participants progressed more rapidly toward relapse, but neither the amount smoked in the first lapse nor its subjective reinforcement predicted progression. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Drinking trajectories following an initial lapse.

Relapse following alcohol treatment is a major problem for individuals who are alcohol dependent, yet little is known about the course of drinking after the initial lapse. In the current study, discrete-time survival analysis and latent growth mixture modeling were used to evaluate the time to first lapse and the trajectories of postlapse drinking in a sample of 563 individuals who received community alcohol treatment. Results showed a decreasing risk of lapsing over time. After the initial lapse, 3 trajectory subgroups provided a parsimonious representation of the heterogeneity in postlapse drinking frequency and quantity, with the majority of individuals reporting light, infrequent drinking. Covariate analyses incorporating demographics, distal risk factors, time to first lapse, and coping behavior as predictors of time to lapse and postlapse drinking trajectories indicated that alcohol dependence and coping behavior were the strongest predictors of lapsing and postlapse drinking behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamic effects of self-efficacy on smoking lapse and relapse.

Self-efficacy (SE) is thought to be critical to success in smoking cessation both as an individual difference and as a dynamic process after a quit attempt. In this study, 214 smokers used palm-top computers to record day-to-day variations in SE during 4 weeks after quitting. SE remained at high and stable levels prior to a 1st lapse but decreased and became more variable thereafter. The authors used event history models with time-varying covariates to assess the effect of daily SE on lapse and relapse risk. Daily SE measures predicted an initial lapse on the subsequent day. However, this relationship was accounted for by stable baseline differences in SE (assessed by questionnaire), rather than by day-to-day dynamics in SE. Progression from 1st lapse to relapse was also examined. In this instance, daily SE predicted subsequent relapse risk, even when baseline SE and concurrent smoking were accounted for, suggesting the importance of SE dynamics for this stage of the relapse process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The consequences of different "lapses" on relapse to heroin seeking in rats.

Although human studies have shown that a lapse, the first violation of abstinence, often induces resumption of drug taking, or relapse, it is not known what aspect of a lapse is critical to relapse or whether this phenomenon can be studied in other species. Rats were trained to self-administer heroin accompanied by a discrete light stimulus. After extinction, different groups experienced different "lapses." Twenty-four hours later, all groups received a test for relapse. It was found that a lapse during which heroin was self-administered, or was presented in close temporal contiguity with lever pressing, induced subsequent heroin seeking. Simple exposure to heroin, or to heroin-related stimuli, during the lapse had little effect on responding in the test for relapse. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Studies on physiological changes due to prolonged standing posture (author's transl)

In relation to static work, an experiment has been made with intention to examine the influence of maintaining standing posture for a long time on human body. The results are as follows: 1) Fluctuation waves of the body weight were classified into two types: type A, a higher amplitude with slow waves, and type B, a lower amplitude with rapid waves. 2) Spectrum analysis on the fluctuation waves of the body weight indicated that type A showed a gradual lowering in relative power in proportion to the wave frequency with the lapse of time, but type B showed a peak in power at around 10 Hz and it increased with the lapse ot time. 3) Action potentials from the left and right gastrocnemium muscles decreased almost simultaneously with the lapse of time in type A with a significant correlation between the left and right, while in type B there was no certain relation between the left and right as well as with the lapse of time. 4) The body weight tended to concentrate on the heel of the dominant foot with the lapse of time. 5) The brain alpha waves increased with the lapse of time, accompanying with a periodical change. 6) In the relationship between the brain alpha waves and the action potential from the gastrocnemius muscle, there was the same cycle at about 1.5 Hz and no change was seen with the lapse of time. 7) There was no significant change in the function of maintaining concentration (TAF). These results suggest that: 1) Besides the reflex mechanism existed as physiological tremor through the stretch reflex loop in maintaining a standing posture, there is a regulation mechanism working to keep balance of the body through the visual organ. 2) The standing posture itself is not always a big stress factor to human body. 3) On the stress by monotonous work, it is necessary to analyse the physiological and psychological load on human body.     

Lapse-induced surges in craving influence relapse in adult smokers: An experimental investigation.

Objectives: Nearly all smokers who lapse experience a full-blown relapse, but the mediating mechanisms that contribute to this relationship are not well understood. A better understanding of these mechanisms would help to advance more effective relapse prevention treatments for smokers. The purpose of this study is to experimentally evaluate the effects of a programmed smoking lapse on smoking relapse and the effects of postlapse changes in craving on relapse. Method: Adult smokers (n = 63) who quit smoking with a brief cognitive–behavioral intervention and self-help materials were randomly assigned to one of two experimental conditions after 48 h of abstinence: No lapse (a no-smoking control/30-min waiting period) or lapse (smoking two cigarettes of their favored brand during a 30-min period). All participants were then followed daily for 14 days. Craving and biochemically verified self-reported abstinence were assessed on each follow-up day. Time (days) to relapse (7 consecutive days of smoking) was the main dependent measure. Results: Results of Cox regression analysis revealed that participants in the lapse condition relapsed more quickly than participants in the no-lapse condition (hazard ratio [HR] = 2.12, 95% confidence interval [CI] = [1.03, 4.35]). These effects were attributable, in part, to episodic increases in craving among participants in the lapse condition only (HR = 12.42, 95% CI =[2.00, 77.1]). Conclusions: Previously abstinent smokers who lapse are at risk for increased cigarette cravings and consequently, full-blown relapse. These results have implications for both cognitive–behavioral treatments for relapse prevention and for medications designed to help smokers manage cravings. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Experimental evidence for a causal relationship between smoking lapse and relapse.

In this study, the authors prospectively evaluated the impact of a smoking lapse on relapse probability. After 4 days of smoking abstinence, 60 smokers were randomly assigned to smoke 5 nicotine-containing or 5 denicotinized cigarettes, or to remain abstinent (no lapse) during a 4-hr time period. Afterward, smoking abstinence was encouraged with monetary incentives, and smoking behavior was tracked for 6 days. Relative to the no-lapse condition, exposure to either of the cigarette types more than doubled the probability of subsequent smoking. Smoking outcomes did not differ between nicotine-containing and denicotinized cigarettes. The data suggest that stimulus factors may play an important role in lapse to relapse processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effect of five smoking cessation pharmacotherapies on smoking cessation milestones.

Objective: Most smoking cessation studies have used long-term abstinence as their primary outcome measure. Recent research has suggested that long-term abstinence may be an insensitive index of important smoking cessation mechanisms. The goal of the current study was to examine the effects of 5 smoking cessation pharmacotherapies using Shiffman et al.'s (2006) approach of examining the effect of smoking cessation medications on 3 process markers of cessation or smoking cessation milestones: initial abstinence, lapse, and the lapse–relapse transition. Method: The current study (N = 1,504; 58.2% female and 41.8% male; 83.9% Caucasian, 13.6% African American, 2.5% other races) examined the effect of 5 smoking cessation pharmacotherapy treatments versus placebo (bupropion, nicotine lozenge, nicotine patch, bupropion + lozenge, patch + lozenge) on Shiffman et al.'s smoking cessation milestones over 8 weeks following a quit attempt. Results: Results show that all 5 medication conditions decreased rates of failure to achieve initial abstinence and most (with the exception of the nicotine lozenge) decreased lapse risk; however, only the nicotine patch and bupropion + lozenge conditions affected the lapse–relapse transition. Conclusions: These findings demonstrate that medications are effective at aiding initial abstinence and decreasing lapse risk but that they generally do not decrease relapse risk following a lapse. The analysis of cessation milestones sheds light on important impediments to long-term smoking abstinence, suggests potential mechanisms of action of smoking cessation pharmacotherapies, and identifies targets for future treatment development. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Self-efficacy for recovery from a lapse after smoking cessation.

Self-efficacy for avoiding any lapse after smoking cessation has often been found to predict maintaining abstinence. The authors measured recent ex-smokers' self-efficacy for recovery of abstinence (SER) after an initial lapse by using the articulated thoughts during simulated situations (G. C. Davison et al, 1983) paradigm. Ss with moderate SER maintained abstinence nonsignificantly longer than did those with high SER, significantly longer than those with low SER. This result is consistent with A. Bandura's (1986) hypothesis that SER should be high enough that ex-smokers do not become hopeless if a lapse occurs, yet not so high that they are tempted to experiment with smoking. The discussion focuses on measurement and conceptualization of SER, in particular its distinctiveness from response–outcome expectations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)