裂解炉炉管基于风险的检验

管式裂解炉炉管受炉内高温及管内介质压力的共同作用,易发生蠕变等现象,因此,对裂解炉炉管进行风险评价尤为重要。应用API 581基于风险的检验规范对炉管的失效可能性及失效后果分别进行定量计算,并由此得到裂解炉炉管的定量风险结果和基于风险的检验周期,为裂解炉的风险控制与管理提供依据。     

细节决定采输卤的成败

通过认真学习《细节决定成败》，结合井矿盐开采的实际，分别以生产过程中的三个细节为主，讨论了在采输卤生产技术控制中的细节的重要性。     

Fast Positive Feedback Between the Adrenocortical Stress Response and a Brain Mechanism Involved in Aggressive Behavior.

Aggressive behavior induces an adrenocortical stress response, and sudden stressors often precipitate violent behavior. Experiments in rats revealed a fast, mutual, positive feedback between the adrenocortical stress response and a brain mechanism controlling aggression. Stimulation of the aggressive area in the hypothalamus rapidly activated the adrenocortical response, even in the absence of an opponent and fighting. Hypothalamic aggression, in turn, was rapidly facilitated by a corticosterone injection in rats in which the natural adrenocortical stress response was prevented by adrenalectomy. The rapidity of both effects points to a fast, mutual, positive feedback of the controlling mechanisms within the time frame of a single conflict. Such a mutual facilitation may contribute to the precipitation and escalation of violent behavior under stressful conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

径向水平井弯曲转向机构影响因素仿真研究

针对径向水平井钻进中钻杆弯曲转向前进运动困难的问题,通过建立弯曲转向机构仿真有限元模型,对其主要影响因素:滑道轨迹曲率、间隙、工作压力、滚轮形状与位置和钻杆壁厚等用ANSYS软件进行仿真研究。研究表明:影响截面变形的主要因素是滑道曲率的改变和滑道摩擦因数,钻井失败时钻杆所受阻力的增大不是因为升高工作压力导致截面变形过大与滑道干涉所致,钻杆经校直段,钻头中轴线与校直中心线存在一定的角度,即钻杆的前进轨迹就会偏离理论值,或与地层干涉,或可能再次发生弯曲变形;另一主要原因是转向器滑道工作恶化。增加钻杆壁厚,降低工作压力和滑道摩擦因数,设计合理弯曲转向机构是解决问题的关键。     

解决高速公路沥青路面早期损坏的技术途径

在对国内大量高速公路调查研究的基础上,论述了我国高速公路沥青路面早期损坏的两种类型:属于短时期内发生的水损坏、车辙、开裂损坏,以及沥青路面的耐久性差、使用寿命短的深层次早期损坏。针对水损坏、车辙、裂缝等局部性质的早期损坏,从路面结构、材料、施工、设计、管理等各方面分析了原因,提出了一系列有效防治高速公路早期损坏的技术措施。     

可控震源施工中电台数据传输不良的原因分析及排除

可控震源在施工中,常常出现各种电台干扰,导致震源数据传输不正常或震源收不到仪器发出的遥控启动信号,影响正常施工.本文介绍了各种电台干扰引起的故障现象,分析了故障产生的原因,给出了故障的排除方法.     

淤泥软基爆炸固结试验研究

对爆炸效应在淤泥软基工程中的应用问题进行了探讨，并首次提出了爆炸在淤泥软基中的分界应力特征以及排水固结及破坏分区的基本模式。为采用动力加速对淤泥软基工程的处理，提供了试验依据，具有实用价值和指导意义。     

数字电视的条件接收系统

数字电视的兴起使人们能够欣赏到高质量的电视节目,伴随数字电视的成熟,条件接收系统(CAS)得到很好的发展。主要介绍数字电视条件接收系统相关技术的发展、基本功能、安全机制、工作原理及其安全性要求。     

Reduction mechanism of tioglycolic acid on keratin fibers using microspectrophotometry and FT-Raman spectroscopy

In order to investigate the reduction mechanism of thioglycolic acid (TG) on the keratin fibers, cross-sectional samples of white human hair treated with TG were prepared. The heterogeneous reaction between TG and keratin fibers involving the diffusion of TG into human hair was analyzed at the molecular level using microspectrophotometry and FT-Raman spectroscopy. The diffusion of TG into human hair clearly increased by increasing the treatment time and by raising pH. The TG relative concentration and the disconnected relative concentration of disulfide (–SS–) groups at various depths of the hair samples with pH 9.0 were in good agreement, indicating that the reaction rate (the disconnection of –SS– groups) was faster than the diffusion rate of TG into human hair. From these experiments, we demonstrated that TG diffuses gradually beyond the cuticle region, and toward the inside of the cortex region along with the disconnection of –SS– groups.     

Failure analysis of a broken tooth

Several days after heart surgery, a patient discovered his upper right canine tooth had broken at the root. Such tooth damage, recognized post-operatively, is usually assumed to be caused by blunt mechanical force from an instrument used by the anesthesiologist during placement of a breathing tube at the start of surgery. In this case, the patient had saved the crown portion of the broken tooth, and it was possible to examine the root fracture characteristics. The curvature and direction of the crack path and natural tooth situation suggested that failure could be described through a cantilever beam model. This was confirmed when a whole extracted sample tooth was embedded and broken by a measured force in a manner consistent with the model. The resulting fracture surface matched that of the patient’s broken canine tooth. However, the high load and force direction necessary to fracture the root was inconsistent with forces applied during the anesthesia procedure. The failure analysis and further investigation indicated tooth clenching on the breathing tube during recovery was the likely cause of fracture. This paper presents an alternate explanation for intubation-related dental injury, demonstrates the practicality of fractographic analysis of biological materials, and introduces a methodology for simulating in vitro tooth settings for mechanical testing.