Crossover from bulk to surface diffusion in the fluctuations of step edges on Pt(111)

Using low-energy electron microscopy we explore the fluctuations of step edges on Pt(111) in the temperature range 1190?K<T<1520?K. Below 1400?K the relaxation times vary with wave vector q as q ³, and above 1400?K as q ², while the observed activation energy changes from 1.25 to 2.75?eV. A discussion shows that surface diffusion is responsible for the rates at low temperatures, and that bulk vacancy diffusion becomes dominant above 1400?K. We infer that a similar crossover must occur for steps on most metal surfaces. The step stiffness is determined as 175 ± 20?meV?nm^?1 at 1500?K.     

The alpha -> beta polytypic transformation in SiC induced by ball milling

The alpha -> beta polytypic transformation in SiC was observed during ball milling at room temperature. Microstructural evolution was characterized on an atomic scale by high-resolution electron microscopy (HREM). HREM observations showed that partial dislocations play an important role in the transformation under the complicated conditions during ball milling.     

婴儿自我认知发生再探

文章在纵向研究基础上,通过横向设计,采用实验室实验、情境观察和母亲访谈相结合的方法考察213名14～24个月婴儿自我认知(视觉和言语方面)的发生.结果表明:1)婴儿自我认知在15～24个月间发生,自我认知能力逐渐出现,随年龄增长而发展.2)视觉自我认知一般发生于第17个月;视觉自我认知无显著的性别差异.3)言语自我认知一般发生于第21个月;男婴言语自我认知获得时间晚于女婴,但在获得言语自我认知后,婴儿言语自我认知无性别差异.4)视觉自我认知对言语自我认知有正向预测作用,视觉自我认知发生早的婴儿,言语自我认知发生的也早.     

不同视角条件下条件推理任务和选择任务的反应模式

在不同视角条件下,要求被试先后完成选择任务和条件推理任务,考察被试在不同视角条件下对两种任务的反应模式。实验结果表明,提供强制情境下对立角色违反规则的信息时,两种任务的反应模式没有明显的关联;提供非强制情境下的反例信息时,两种任务的反应模式出现分离趋势;当对规则的语义关系进行充分非必要或必要非充分关系的解释时,两者又趋于一致。分析表明,被试采用多种策略完成选择任务,而是否采用条件推理的逻辑取决于特定情境能否激活这种逻辑。     

What subjective experiences determine the perception of falling asleep during sleep onset period?

Sleep onset is associated with marked changes in behavioral, physiological, and subjective phenomena. In daily life though subjective experience is the main criterion in terms of which we identify it. But very few studies have focused on these experiences. This study seeks to identify the subjective variables that reflect sleep onset. Twenty young subjects took an afternoon nap in the laboratory while polysomnographic recordings were made. They were awakened four times in order to assess subjective experiences that correlate with the (1) appearance of slow eye movement, (2) initiation of stage 1 sleep, (3) initiation of stage 2 sleep, and (4) 5 min after the start of stage 2 sleep. A logistic regression identified control over and logic of thought as the two variables that predict the perception of having fallen asleep. For sleep perception, these two variables accurately classified 91.7% of the cases; for the waking state, 84.1%.     

Decreased parahippocampal activity in associative priming: evidence from an event-related fMRI study

In recent years, there has been intense debate on the neural basis of associative priming, particularly on the role of the medial temporal lobe (MTL) in retrieving associative information without awareness. In this study, event-related fMRI was used while healthy subjects performed a perceptual identification task on briefly presented unrelated word pairs and an associative recognition memory task. Contamination of priming by explicit memory was successfully controlled, as associative priming and explicit memory were dissociated on the behavioral level. The fMRI results showed a functional dissociation within the MTL with respect to associative priming effects. The right parahippocampal cortex, but not the hippocampus, showed decreased activation for old vs. new pairs and old vs. recombined pairs (associative priming). The bilateral hippocampus and the right parahippocampal cortex were involved in explicit associative memory. These data provide evidence that subregions of the MTL participate in associative priming even when explicit involvement was controlled. Thus, different regions within the MTL play distinct roles in explicit and implicit associative memory.     

儒家“复活”的“意识”前提——张祥龙《儒家原文化主导地位之含义》编后记

到目前为止,张祥龙最重要的两部著作--<海德格尔思想与中国天道>(三联书店1996年初版、2007年修订版)、<从现象学到孔夫子>(商务印书馆2001年初版),都是一边谈着现代西方以现象学为主的欧陆哲学,另一边谈着中国古代以孔子为主的先秦哲学,可谓典型意义上的东西方比较哲学研究.1949年出生于香港九龙的张祥龙,1977年考入北京大学哲学系,并在张岱年先生指导下完成了本科毕业论文<庄子的人生哲学>,1988年8月获美国俄亥俄州托莱多大学哲学硕士学位,1992年2月获美国纽约州立布法罗大学哲学博士学位,现为北京大学哲学系暨外国哲学研究所教授.     

敦煌寺学与敦煌佛教入门读物之关系探析

寺学是晚唐归义军时期敦煌教育的一种特殊而重要的形式,但在寺学使用什么样的教材方面,学者们大都拘泥于传统的儒家典籍,未认识到寺学以佛学教育为主这一性质。佛教入门读物,就是以宣传和普及佛教常识为目的,部分或系统介绍佛教名数、义理知识,使初学者得到基本佛教常识的书籍。本文通过对二者特点的分析,来探究它们之间的关系。     

略论蒲益智旭的《辟邪集》对天主教天主观的批判

明末蒲益智旭的<辟邪集>采用以子之矛攻子之盾的办法作为论辩策略,对当时传入中国的天主教给予了全面而锐利的批判,以对天主教天主观的批判作为核心,尤其是对天主全能以及恶的来源的批判,可谓击中了天主教的要害之处.