模拟工程车辆换挡瞬态的动力学仿真模型

以美国CATpillar公司631型轮式铲运机为例，介绍一种经验证的工程车辆的动力学建模方法。同时特别分析了该机带有5个行星排的动力换档变速箱在齿轮换挡过程中的动力学问题并提出了建模方法。对于工程机械计算机仿真模型试验、系统设计参数优化、传动系统的零件寿命的评估尤其是车辆换挡平顺性的研究具有一定的实用意义。     

Psychophysiological Assessment During Exposure in Driving Phobic Patients.

A comprehensive assessment of fear or anxiety requires measurement of both self-report and physiological responses. Respiratory abnormalities have been rarely examined during real-life exposure, although they are an integral part of fear. Twenty-one women with a specific driving phobia and 17 nonphobic women were psychophysiologically monitored during 2 highway-driving sessions; phobic women completed an additional session. Respiratory movements, end-tidal partial pressure of carbon dioxide, an electrocardiogram, skin conductance, and skin temperature were recorded. Phobic patients differed from control participants both physiologically and experientially before, during, and after exposure. Effect size during exposure was large for the authors' measure of hyperventilation. Discriminant analysis indicated that multiple physiological measures contributed nonredundant information and correctly classified 95% of phobic and control participants. Thus, selected respiratory and autonomic measures are valid diagnostic and therapeutic outcome criteria for this situational phobia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Automatic affective responses to smoking cues.

The authors examined automatic emotional reactions to smoking cues among 35 smokers and 25 nonsmokers (32 women and 28 men), using a novel implicit measure, the Affect Misattribution Procedure. Associative-learning theories of addiction suggest that smokers develop positive responses to cues linked to the rewarding effects of nicotine. Prior research, however, has yielded mixed evidence for whether smokers have favorable or unfavorable automatic responses to smoking cues. These findings may depend on the methods used to measure implicit responses. Using the Affect Misattribution Procedure, the authors found that nonsmokers responded to smoking cues with clear negative affect, whereas smokers' responses depended on individual differences in current smoking withdrawal. Smokers having withdrawal symptoms and those most motivated to smoke showed favorable emotional responses to smoking cues, but those with no withdrawal or low motivation to smoke showed negative responses. These results help integrate previous studies finding that smokers have negative automatic responses to cigarettes with those studies finding that smokers' responses were relatively positive. The results are important for theories that emphasize the role of cue conditioning in maintaining addiction because these theories assume, consistent with the current findings, that smoking cues can take on positive reward value. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of repeated acquisitions and extinctions on response rate and pattern.

The procedure developed by R. A. Rescorla (2002) was used to study the effects of repeated acquisitions and extinctions of head entry responses into a food cup by rats. In each of 4 20-session phases, food was delivered at the end of particular 30-s auditory and visual stimuli, but not at the end of different 30-s auditory and visual stimuli. Based on response rates to individual stimuli and compound stimuli, the increase in response rate in acquisition occurred more rapidly than the decrease in extinction. Acquisition, but not extinction, occurred faster after successive transitions between acquisition and extinction. Temporal gradients of responding developed during acquisition and remained during extinction. Conclusions based on mean response rate, temporal gradients, and transfer tests were consistent. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

泉州东、西塔场地抗震性能评价和场地地震动参数估计

本文首先结合东、西塔场地实际情况,对其场地类别、地基震害进行评判;然后采用综合概率法对工程场地进行地震危险性分析;最后结合试验测定的场地岩土力学性能,采用一维等效线性化波动法计算地震动土层反应,得到供结构地震反应分析的场地地震动参数。     

Sleep Responses to Light and Dark Are Shaped by Early Experience.

Light regulates sleep timing through circadian entrapment and by eliciting acute changes in behavior. These behaviors are mediated by the subcortical visual system, retinorecipient nuclei distinct from the geniculocortical system. To test the hypothesis that early visual experience shapes light regulation of behavior, the authors recorded sleep in albino rats reared in continuous dark, continuous light, or a 12-hr light-dark cycle. Dark rearing strengthened and light rearing weakened acute responses to light, including light modulation of REM sleep, a marker for pretectal function in albino rats. However, neither dark nor light rearing altered daily amounts of wakefulness, non-REM sleep, or REM sleep. Thus, light and dark rearing might differentially affect the balance between acute and circadian responses to light that, in concert, govern sleep timing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Older spouses' perceptions of partners' chronic arthritis pain: Implications for spousal responses, support provision, and caregiving experiences.

This study of older patients with osteoarthritis and their spouses examined concordance between patients' and spouses' reports of patients' pain severity and the association of concordance with support and caregiving outcomes. Patients and spouses independently viewed videotapes of the patient performing simulated household tasks and provided ratings of patients' pain. Spousal overestimation of patients' pain was the most common type of nonconcordance. Spouses who were accurate in their perceptions of their partner's level of pain during a log-carrying task responded less negatively and provided emotional support that was more satisfying to patients. In addition, spouses who were accurate in their perceptions of their partner's pain during the log-carrying task reported less stress from providing support and assistance. Future research that uses such observational methods may be highly useful for understanding the effects of chronic illness on older couples. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Review of Helping Bereaved Children, Second Edition: A Handbook for Practitioners.

Reviews the book, Helping Bereaved Children, Second Edition: A Handbook for Practitioners edited by Nancy Boyd Webb (see record 2002-02276-000). When health policy decision-makers understand the greater societal benefits of providing evidence-based bereavement support to children and adolescents, our country will have coordinated, accessible, and comprehensive Loss Support programs for every family member. Until then, we are fortunate to have this guide to educate us on how to best support our most vulnerable family members when someone loved dies. Although the title specifically targets practitioners, I believe that the plain language and holistic approach would assist parents and other adults in supporting these children and teens. I am pleased to endorse this book as an excellent resource for professionals and lay people alike as we all strive to ensure that our children receive the best support for the grief they experience in their young lives. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A role for sweet taste: Calorie predictive relations in energy regulation by rats.

Animals may use sweet taste to predict the caloric contents of food. Eating sweet noncaloric substances may degrade this predictive relationship, leading to positive energy balance through increased food intake and/or diminished energy expenditure. These experiments were designed to test the hypothesis that experiences that reduce the validity of sweet taste as a predictor of the caloric or nutritive consequences of eating may contribute to deficits in the regulation of energy by reducing the ability of sweet-tasting foods that contain calories to evoke physiological responses that underlie tight regulation. Adult male Sprague-Dawley rats were given differential experience with a sweet taste that either predicted increased caloric content (glucose) or did not predict increased calories (saccharin). We found that reducing the correlation between sweet taste and the caloric content of foods using artificial sweeteners in rats resulted in increased caloric intake, increased body weight, and increased adiposity, as well as diminished caloric compensation and blunted thermic responses to sweet-tasting diets. These results suggest that consumption of products containing artificial sweeteners may lead to increased body weight and obesity by interfering with fundamental homeostatic, physiological processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sex differences in biobehavioral responses to threat: Reply to Geary and Flinn (2002).

Early theories of stress obscured differences in how men and women respond to threat. The tend-and-befriend model attempted to partially redress that oversight by identifying biological and behavioral patterns of stress responses distinctive to females, responses that are markedly social. Although men's behavior under stress may also be social, at least under certain circumstances, extending the tend-and-befriend model to men is premature and potentially flawed, from the vantage points of the underlying biology and the behavioral stress responses it may help to foster. (PsycINFO Database Record (c) 2010 APA, all rights reserved)