Spontaneous growth of tin whiskers on tin−rare-earth alloys

Tin whisker growth has been observed on the surface of bulk Sn–Nd alloys with Nd contents of 30, 5 and 0.5 wt%, under ambient conditions of temperature and atmosphere. It is shown that the whiskers originate from the area of Sn–Nd intermetallic compounds after a very short incubation period and that they exhibit a relatively high growth rate on the surface of the bulk alloys. The results show that these Sn-based, rare-earth alloys have a very strong propensity to grow tin whiskers, i.e. this rare-earth element in tin is a catalytic agent for whisker growth. Direct evidence is also shown that whiskers can grow from the surface of a bulk Sn-based alloy.     

Interactions between interfacial dislocations and γ/γ′ interface during high temperature – low stress creep in nickel-based single crystal superalloy

ABSTRACT

The interaction between interfacial dislocations and γ/γ′ interface is critical to the high temperature creep properties of single crystal superalloys. However, only a few studies have paid attention to the detailed structure such as local interfacial morphologies and the elemental distribution around interfacial dislocations. In this paper, the interfacial protrusions and related dislocations in a single crystal superalloy after creep at high temperature – low stress have been investigated in detail. It is found that the morphology and size of the interfacial protrusions remain almost the same during the early and middle stages of high temperature creep, which indicates a local equilibrium at the interfacial protrusions. Steps at different height are formed at the γ/γ′ interface at the initial stage of high temperature creep since dislocations could move along the γ/γ′ interface, which indicates that dislocation motion at different creep stage may affect the morphology of γ/γ′ interface.     

The orientation and temperature dependences of dislocation velocity in Ni 3 Al single crystals

The average velocities of screw dislocations in Ni 3 Al single crystals have been directly measured as a function of resolved shear stress (RSS) and orientation in the temperature domain of the flow stress anomaly using the etch-pit technique. The velocity was found to be extremely sensitive to the RSS in all cases. In contrast with ordinary metals, the screw dislocation velocities in Ni 3 Al show anomalous behaviour; under a constant RSS, the velocities decrease dramatically with increasing temperature. Furthermore, the velocities and the tension-compression asymmetry of the velocities depend on the orientation of applied stress.     

Capturing and evaluating blinks from video-based eyetrackers

Blinks are related to several emotional states, and the present report describes a simple, reliable way to measure blinks from the video stream of an eye obtained during eyetracking, where the source of the eye video is a video camera attached to a head-mounted eyetracker. Computer vision techniques are employed to determine the moments that a blink starts and ends, for the purpose of calculating blink frequency and duration. The video is first processed to show blocks of eyelid and pupil movements, and is then analyzed for blink starts and ends. The moment of a blink start is reported when the eyelid starts to move quickly, exceeding a predetermined threshold. The end of a blink arises when the pupil size increases by less than a separate threshold. We observed several different blink patterns from different subjects, and our algorithm was designed to work for all of these patterns. We evaluated our algorithm by manually measuring the true blinks of five different subjects while they were eyetracked. To test the sensitivity and specificity of the algorithm, we employed a series of threshold values to plot the receiver operating characteristic curves. Using the best thresholds, we achieved excellent sensitivity (>90 %) and specificity (>99 %) over the five subjects. Potential applications of this research include real-time, nonintrusive, continuous and automated measurements of mental workload and other emotional states related to blink rates and durations.     

大鱼小池效应研究回顾及展望

大鱼小池效应(Big Fish Little Pond Effect)是解释不同教育情境中学生自我概念水平的一个特定概念,Marsh将其定义为：能力同等的学生,在平均成绩较高的学校或班级里的学业自我概念较低,而在平均成绩较低的学校或班级则学业自我概念会较高。大鱼小池效应包括学生采用概括他人和特定他人的比较标准所分别产生的同化效应和对比效应,社会比较对学业自我概念形成具有特定影响。大鱼小池效应的未来研究可以从研究方法的改进、调节变量的控制和跨文化比较等方面拓展。     

Investment in body image among patients diagnosed with or at risk for malignant melanoma

We examined investment in body image among 48 patients diagnosed with, or at risk for malignant melanoma (MM), as well as factors hypothesized as related to increased investment, such as gender, perceived stress, mood, fatigue, and personality characteristics. Investment in body image was evaluated using the Measure of Body Apperception [Carver, C. S., Pozo-Kaderman, C., Price, A. A., Noriega, V., Harris, S. D., Derhagopian, R. S., Robinson, D. S., & Moffat, F. L. Jr. (1998). Concern about aspects of body image and adjustment to early state breast cancer. Psychosomatic Medicine, 60, 168–174]. Results showed that women reported more concerns about physical appearance than men, and patients with MM exhibited more concerns about body integrity than at-risk patients. Concerns about body integrity were related to more compulsive personality characteristics, whereas concerns about appearance were associated with more histrionic personality characteristics. Body image investment was related to poorer adjustment as indicated by heightened symptoms of fatigue and stress. This study suggests that further research on investment in body image in this patient population is warranted.     

萨特在人的发展问题上的"责任"困境

在萨特的人学理论中,“自由”无疑是一个最重要的范畴。存在就是自由,自由的绝对性使得它成为一切事物及其自身的根据。然而,为了保证人的发展的合理性,在高扬了自由之后,萨特力图在最后解决的却一直是“自由”与“责任”的统一,这样,萨特将自己陷于一个无从解脱的困境之中：由于绝对自由论的前提,他所倡导的对自己、对他人,乃至对世界的“责任”,最后却成了人们逃避责任的一种托辞。     

幼儿心理理论与社会行为发展关系的初步研究

研究短期跟踪57名新进入幼儿园的幼儿,测查他们心理理论(theory of mind)和社会行为的发展水平.结果表明,幼儿心理理论的发展差异确实与他们的社会行为发展存在某种密切关系,但其与社会行为发展的不同方面似乎存在不同的关系模式.对这些不同的关系模式,文中分别从幼儿的心理状态认识、执行性控制能力发展和个性倾向等方面进行了探讨.     

Personal and cultural differences in responding to criticism in three countries

The present study investigated whether verbal aggression, argument approach, argument avoidance or assertiveness had any effect on how participants in three countries responded to criticism. Consistent with the first hypothesis, men were significantly more aggressive, assertive, less avoidant, and approached argument more than women. However, men did not respond more assertively to criticism. As predicted in the second hypothesis, US Americans responded more assertively to criticism than did Japanese and Chinese. The third hypothesis predicted that verbal aggression, argument approach, argument avoidance and assertiveness would be associated with a more assertive response to criticism. The data obtained were only partially consistent with the third hypothesis. While only a small number of participants in this study indicated that they would respond to criticism with silence, US Americans used silence to mean anger while for Chinese silence showed personal embarrassment. Very few Japanese selected silence as an option for responding to a neighbor's criticism. The implications of these results are discussed.     

前、后注意网络的关系--返回抑制和Stroop干扰效应

将IOR范式与Stroop任务相结合,试图从探讨IOR与Stroop干扰效应之间的关系来推测AAN和PAN之间的关系以及IOR与注意之间的关系。结果表明,在控制条件下出现了显著的IOR,在Stroop条件下没有出现明显的IOR;提示和非提示位置上均出现了显著的Stroop干扰效应,但提示位置上的干扰量要显著低于非提示位置。从IOR和Stroop干扰效应之间的关系可推知,PAN和AAN是两个有交互影响的注意网络,AAN对PAN有压制作用,而PAN对。AAN也有一定的影响。最后,作者对返回抑制与注意问的关系进行了深入的讨论。