煤基SN级5W-30汽油机油行车试验研究

行车试验是全面评价汽油机油（润滑油）性能的重要方法。分别对自研煤基5W-30汽油机油和市售SN 5W-30汽油机油进行10 000 km行车试验研究，依据国家标准GB/T 8028—2010《汽油机油换油指标》对不同行驶里程下的旧油进行理化性能分析。结果表明：10 000 km行车试验后，2种汽油机油性能指标均未超过换油指标要求，仍有较大性能余量；相比市售SN 5W-30汽油机，自研煤基汽油机油行车试验后铁含量和酸值增加更小，碱值余量更大，表现出更优异的润滑性能、抗氧化性能、抗磨损性能和清洁分散性能。     

Time evolution of entanglement and bistability of two coupled quantum dots in a driven cavity

Abstract

The time evolution of entanglement between two quantum dots (QDs) trapped inside a cavity driven by a coherent quantized field is studied. In the presence of dissipation, entanglement shows many interesting features such as sudden death and revival, and finite steady state value after sudden death. We also investigate dependence of entanglement on dot variables and its relation to bistability. It is found that entanglement vanishes when the cavity field intensity approaches the upper branch of the bistability curve. When the cavity is driven by a modulated field in the presence of dissipation, it can periodically generate entanglement, which is much larger than the maximum value attained in the steady-state for this system but the dots are never fully entangled.     

Efficient driver drowsiness detection at moderate levels of drowsiness

Previous research on driver drowsiness detection has focused primarily on lane deviation metrics and high levels of fatigue. The present research sought to develop a method for detecting driver drowsiness at more moderate levels of fatigue, well before accident risk is imminent. Eighty-seven different driver drowsiness detection metrics proposed in the literature were evaluated in two simulated shift work studies with high-fidelity simulator driving in a controlled laboratory environment. Twenty-nine participants were subjected to a night shift condition, which resulted in moderate levels of fatigue; 12 participants were in a day shift condition, which served as control. Ten simulated work days in the study design each included four 30-min driving sessions, during which participants drove a standardized scenario of rural highways. Ten straight and uneventful road segments in each driving session were designated to extract the 87 different driving metrics being evaluated. The dimensionality of the overall data set across all participants, all driving sessions and all road segments was reduced with principal component analysis, which revealed that there were two dominant dimensions: measures of steering wheel variability and measures of lateral lane position variability. The latter correlated most with an independent measure of fatigue, namely performance on a psychomotor vigilance test administered prior to each drive. We replicated our findings across eight curved road segments used for validation in each driving session. Furthermore, we showed that lateral lane position variability could be derived from measured changes in steering wheel angle through a transfer function, reflecting how steering wheel movements change vehicle heading in accordance with the forces acting on the vehicle and the road. This is important given that traditional video-based lane tracking technology is prone to data loss when lane markers are missing, when weather conditions are bad, or in darkness. Our research findings indicated that steering wheel variability provides a basis for developing a cost-effective and easy-to-install alternative technology for in-vehicle driver drowsiness detection at moderate levels of fatigue.     

Adolescent exposure to drink driving as a predictor of young adults’ drink driving

The purpose of this study was to investigate the influence of exposure to others’ drink driving during adolescence on self-reported driving under the influence (DUI) of alcohol in young adulthood. Data were drawn from 1956 participants with a driving license enrolled in the International Youth Development Study from Victoria, Australia. During 2003 and 2004, adolescents in Grades 7, 9 and 10 (aged 12–17) completed questionnaires examining whether they had ridden in a vehicle with a driver who had been drinking, as well as other demographic, individual, peer and family risk factors for DUI. In 2010, the same participants (aged 18–24) then reported on their own DUI behaviour. 18% of young adults with a driving license reported DUI in the past 12 months. Exposure to others’ drink driving during adolescence was associated with an increased likelihood of DUI as a young adult (OR = 2.13, 95% CI 1.68–2.69). This association remained after accounting for the effects of other potential confounding factors from the individual, peer and family domains (OR = 1.62, 95% CI 1.23–2.13). Observing the drink driving behaviours of others during adolescence may increase the likelihood of DUI as a young adult. Strategies to reduce youth exposure to drink driving are warranted.     

浅论特种玻璃退火窑的传动

特种玻璃退火窑的传动有其特殊性,高温区的辊子材质采用陶瓷辊,其传动方式有三种,对特种玻璃退火窑传动的一些体会与大家探讨。     

两轴驱动矿石胶带机的变频改造

针对两轴驱动矿石胶带机的变频改造方案进行分析,着重考虑与原控制系统的衔接问题以及在实施过程中出现的两轴转速不同步问题,采用S1200型PLC,利用PROFIBUS通信功能,用DP线PLC将两台变频器的CU320有效联接起来,最终达到预期目的。     

一种新型侧驱动压料机构

针对汽车覆盖件冲压成形模设计中侧整形与侧翻边的侧压料过程,提出了一种新型的侧驱动压料机构。与传统的侧压料机构相比,这种机构将固定在斜楔滑动块上的侧压芯安装在通过斜楔上滑块约束的主压芯上,优化了模具结构,降低了生产成本。将此机构运用在某车型侧围的侧整形部位,生产实践证明,机构切实可行,为其他侧压料的模具结构设计提供了参考。     

传动轴过渡套的检测方法研究

针对焊接在传动轴上的过渡套，提出了一种采用超声波测厚仪与钻孔相结合的方法来检测过渡套内圆深度是否超差，从而在不损坏传动轴的条件下判定过渡套是否合格，并证实了此方法对过渡套受力强度及传动轴动平衡不会造成任何不良影响。通过对过渡套检测方法的研究，为后续传动轴品质控靠0提供了理论依据。     

Effect of cycle time and duty cycle on psychophysically determined acceptable levels in a highly repetitive task

Psychophysical methodology has been used to develop guidelines for lifting and more recently similar methods have been applied to repetitive upper limb movements. While a range of cycle times are usually used, there is often no control for duty cycle. The purpose of this paper is to present psychophysically determined acceptable torques for a common upper limb task, with both cycle time and duty cycle conditions set by the researcher. Eight female participants, sitting at adjustable workstations, performed a simulated in-line screw running task. A computer-controlled torque motor applied a torque every 3, 6, 12 or 20?s with a duty cycle of 25, 50 or 83%. The participants worked with one set of conditions each day and self-selected the highest torque that they felt was acceptable without developing undue pain and discomfort. Duty cycle was found to significantly affect the amount of torque selected. With duty cycle controlled, cycle time was no longer found to have any significant effect on selected torque. Acceptable torques for 25, 50 and 83% duty cycles were 1.09, 0.9 and 0.73 Nm. Discomfort and stiffness were concentrated on the back of the hand and on the thumb web. These findings suggest that increased perception of discomfort with increased frequency (decreased cycle time) may be related to decreased rest/recovery time for muscles.     

Driving behaviors in early stage dementia: A study using in-vehicle technology

According to the Alzheimer's Association (2011), (1) in 8 people age 65 and older, and about one-half of people age 85 and older, have Alzheimer's disease in the United States (US). There is evidence that drivers with Alzheimer's disease and related dementias are at an increased risk for unsafe driving. Recent advances in sensor, computer, and telecommunication technologies provide a method for automatically collecting detailed, objective information about the driving performance of drivers, including those with early stage dementia. The objective of this project was to use in-vehicle technology to describe a set of driving behaviors that may be common in individuals with early stage dementia (i.e., a diagnosis of memory loss) and compare these behaviors to a group of drivers without cognitive impairment. Seventeen drivers with a diagnosis of early stage dementia, who had completed a comprehensive driving assessment and were cleared to drive, participated in the study. Participants had their vehicles instrumented with a suite of sensors and a data acquisition system, and drove 1–2 months as they would under normal circumstances. Data from the in-vehicle instrumentation were reduced and analyzed, using a set of algorithms/heuristics developed by the research team. Data from the early stage dementia group were compared to similar data from an existing dataset of 26 older drivers without dementia. The early stage dementia group was found to have significantly restricted driving space relative to the comparison group. At the same time, the early stage dementia group (which had been previously cleared by an occupational therapist as safe to drive) drove as safely as the comparison group. Few safety-related behavioral errors were found for either group. Wayfinding problems were rare among both groups, but the early stage dementia group was significantly more likely to get lost.