Attention bias in nicotine withdrawal and under stress.

Drug motivation models postulate that attention biasing toward smoking-related cues is a cognitive mechanism supporting continued or renewed drug use, and they predict that drug use history, deprivation, and distress should modulate the extent of this bias. The present study used the modified Stroop paradigm to extend past research regarding attention biasing toward smoking and unpleasant, pleasant, and neutral words among adult nonsmokers and daily smokers. Both nonsmokers and smokers showed differential attention toward unpleasant and pleasant cues, particularly pleasant cues, but did not show a unique bias toward smoking-related stimuli. Results suggested that, among smokers, nicotine deprivation and exogenous stress (threat of electric shock) have a nonadditive effect on attention toward pleasant cues but no effect on attention to smoking cues specifically. Similarly, instructing smokers that they would have an opportunity to smoke did not significantly increase the bias of nicotine-deprived smokers' attention toward smoking-related cues, relative to arousing unpleasant and pleasant cues. Overall, results suggest that smokers' attention may be biased toward both smoking-related and other salient cues when deprived of nicotine and anticipating an opportunity to smoke. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

用于多组分分离的中间取料矩形级联的优化设计

多组分同位素混合物的某一中间组分通常在分离级联的中间某级达到峰值,但一般的级联均采用从级联组两端取出产品和废料的工艺。为得到丰度较高的中间组分产品,最好在级联中间取料。本工作研究矩形级联中使用中间取料方式以提高级联分离的中间组分丰度。通过数值模拟计算和数值优化,研究了级联两端取料量和级联供取料位置等参数对中间取料中目标组分丰度的影响。采用单参数分析,估计了级联各参数的取值范围以及它们对目标组分丰度的影响。通过优化计算,在供料丰度和流量不变、产品流量不变的情况下,得到了可以生产更高丰度中间组分产品的级联。     

An overview of instrumentation and control systems of a Korea standard nuclear power plant: A signal interface standpoint

This paper presents an overview of instrumentation and control (I&C) systems of a pressurized water reactor (PWR) type nuclear power plant (NPP) in Korea. Yonggwang unit 3, which was constructed as a basis model for a Korea standard nuclear power plant (KSNP), is selected as an example for the presentation. This overview is derived from analyzing the I&C systems based on a top-down approach. The I&C systems consist of 30 systems. The 183 I&C cabinets are also analyzed and mapped to the systems. The overview is focused on an interface between the systems and the cabinets. This information will be used to understand the implementation of the I&C systems and to group the systems for an upgrade.     

Do adolescent smokers experience withdrawal effects when deprived of nicotine?

This is the first controlled prospective study of the effects of nicotine deprivation in adolescent smokers. Heart rate and subjective withdrawal symptoms were measured over and 8-hr period while participants smoked normally. Seven days later, participants were randomized to wear a 15-mg (16-hr) nicotine patch or placebo patch for 8 hr, and they refrained from smoking during the session. Those wearing the placebo experienced a decrease in heart rate across sessions and an increase in subjective measures of nicotine withdrawal. Those wearing the active patch also reported significant increases for some subjective symptoms. Expectancy effects were also observed. The findings indicate that adolescent smokers experience subjective and objective changes when deprived of nicotine. As in previous research with adults, expectancies concerning the effects of nicotine replacement also influenced perceptions of withdrawal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Emotional modulation of cognitive control: Approach–withdrawal states double-dissociate spatial from verbal two-back task performance.

Emotional states might selectively modulate components of cognitive control. To test this hypothesis, the author randomly assigned 152 undergraduates (equal numbers of men and women) to watch short videos intended to induce emotional states (approach, neutral, or withdrawal). Each video was followed by a computerized 2-back working memory task (spatial or verbal, equated for difficulty and appearance). Spatial 2-back performance was enhanced by a withdrawal state and impaired by an approach state; the opposite pattern held for verbal performance. The double dissociation held more strongly for participants who made more errors than average across conditions. The results suggest that approach–withdrawal states can have selective influences on components of cognitive control, possibly on a hemispheric basis. They support and extend several frameworks for conceptualizing emotion–cognition interactions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

渐进矫直原理分析及拉矫机应用研究

介绍了渐进矫直的基本原理 ,分析了渐进拉矫机的结构特点及渐进矫直技术在提高铸坯质量和拉矫速度方面的应用     

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研究气井积液的成因及条件对于防止气井积液十分重要,文章采用气井中被气流携带向上运动的液滴趋于扁平形状的新观点,导出了一个新的气井连续排液最小携液速度和产量计算公式,该公式计算出的最小携液速度和产量比经典的Turner最小携液速度和产量公式计算结果要小,但实例计算表明更符合现场实际情况。此外,为了便于现场应用,在分析了影响气井排液的各种因素后,文章进一步给出了新公式的简化计算形式,该模型还解释了为什么许多气井产量在大大低于Turner的最小携液产量时,仍能继续正常生产的原因。     

Husky分层抽汲技术在中原油田的应用

以中原油田濮3-138井为研究对象,应用新型封隔器将多个射孔段进行隔离,应用抽汲设备及技术对目的层位抽汲取样,通过对单井分层抽汲,定量确定其产能及含水,为油田开发提供分层数据.经过对10口井的分层抽汲,确定出24个层段的产能和含水.分析结果对油藏的分层认识具有重要的指导意义.     

发动机排气管专用机床设计

为了研究解决发动机排气管大批量高效生产和加工精度的问题,通过对加工机床方案的比较与选择,介绍了一种新颖的专用加工机床研制及机床结构设计特点.     

侧脑室注射东莨菪碱对吗啡依赖大鼠戒断反应的抑制作用

目的 观察非选择性毒蕈碱(M)受体拮抗剂东莨菪碱、选择性M1 受体拮抗剂哌拉唑嗪以及选择性M2受体拮抗剂美索四氨对吗啡戒断反应的影响。方法 采用吗啡依赖大鼠模型侧脑室注射上述药物, 并用腹腔注射纳洛酮诱发戒断反应, 记录60 min 内戒断症状。结果 侧脑室注射东莨菪碱(25, 50 μg)、哌拉唑嗪(20 μg)和美索四氨(25 μg)可明显抑制由纳洛酮诱发戒断反应, 东莨菪碱减轻吗啡戒断症状呈明显量效关系。结论 侧脑室注射东莨菪碱能减轻吗啡戒断反应, 提示中枢胆碱能神经毒蕈碱(M)受体在吗啡依赖和耐受过程中起重要作用。