摘要：电解水反应包括析氢和析氧反应.相对于2电子转移的析氢反应,4电子转移的析氧反应比较缓慢.因此,理解析氧反应机制有助于设计高效电催化剂.其中析氧反应机制可以分为传统吸附机制和直接氧析出机制.在本文中,我们将蜂窝状Ni_(3)N-Co_(3)N生长在碳布上来调研其直接氧析出机制.密度泛函理论和原位拉曼证明了Ni_(3)N-Co_(3)N在反应过程中是直接氧析出机制,其中Ni_(3)N和Co_(3)N共同拉拽OH^(-)、劈裂H-O和吸附另外的OH^(-)基团,从而降低了反应活化能.不仅如此,蜂窝状结构和导电基体有助于结构稳定和提高氧气释放速率.因此,Ni_(3)N-Co_(3)N/CC在10和100 mA cm^(-2)电流密度下提供了320和495 mV的小过电势.同时,它也拥有更好的长期稳定性.

摘要：Pedestrians intercepted near the exits of a subway station in downtown hong kong were surveyed using a questionnaire and quota sampling in October 2012. The survey sampled 408 residents and tourists aged 16 and above. The awareness of the 16 ads. ranged from 18 to 80 percent with an average 43.5 percent. The layouts of the two subway ads. received highest awareness were focused and had a clear distinction between foreground and background. Average ad awareness was comparable to that reported in two similar studies of subway ads. conducted in the 1990s. Average ad awareness of subway ads. was higher than that of outdoor advertising measured using similar methodology in 2010s. Respondents demonstrated positive attitudes toward subway advertising, and reported that subway ads. that drew their attention were those with creative ideas, vivid colors, and large-than-life size execution.

摘要：合成维度的概念可广泛用于在低维平台上研究高维物理.比如四维拓扑可被利用于操控三维真实空间中波的传播.本文通过实验验证了调制连续耦合声波导的设计可实现三维结构中的声拓扑态泵浦,所设计的系统具有受四维系统拓扑保护的边态和角态.通过控制合成空间中的相位和相应声源模式的激励,可以在特定空间方向上实现拓扑边界态与角态的泵浦.此外,本文还研究了角到角泵浦对无序的鲁棒性,实验结果表明该系统具有强鲁棒性.所得研究结果提供了通过连续耦合波导实现拓扑声泵浦的一般策略,并为探索连续系统中的高维拓扑相位提供了新的思路.

摘要：对一门语言语音系统的习得包括对其音位配列规律的习得,前人研究中广泛地发现了已习得语言音位配列规律对语音感知的影响。例如Dupoux et al.(1999)对日语母语者的感知研究发现,他们在听辅音丛(*CC)时,可能在中间幻听到元音,这与日语中不允许辅音丛(*CC)有关。本研究关注粤语—英语双语者在感知音段序列时,是否会受到粤语和英语的影响。我们的实验设计以Dupoux et al.(1999)为基础。被试为20位粤英双语使用者,他们的第一语言为粤语,从4岁左右开始习得英语作为第二语言。实验刺激项是形为V_(1)C_(1)(V_(x))V_(2)C_(2)的假词,其中元音辅音是英语和粤语中常见的音段;刺激项中一半刺激项里C_(1)C_(2)的组合对应英语中存在的音节首辅音丛,例如[kl,gl],另一半刺激项里C_(1)C_(2)对应英语音节首中不存在的辅音丛,例如[km,gm];假词中间V_(x)的时长分为连续统上的六个长度,从0毫秒(即无元音)到95毫秒。每听到一个假词,被试判断C_(1)C_(2)中间是否有元音存在。经过线性混合模型的检验,实验结果显示:(1)就元音V_(x)的时长而言,时长越长,被试感知到元音的概率越高;(2)在V_(x)为0毫秒(即没有元音)时,粤英双语被试仍然在一定程度上感知到元音;(3)当C_(1)C_(2)组合对应英语中存在的音节首辅音丛时,例如[kl,gl],被试感知到元音的概率显著低于当C1 C2组合对应英语音节首中不存在的辅音丛的情况,例如[km,gm];(4)元音时长和C_(1)C_(2)是否对应英语辅音丛之间没有交互作用。实验结果(2)表明,在粤英双语使用者感知音段序列时,粤语的声韵搭配规律在起作用,这和Dupoux et al.(1999)等实验中日语母语者在辅音丛(*CC)中间幻听到元音相似;实验结果(3)表明,英语的音位配列规律也在起作用,影响被试的判断,使其在C_(1)C_(2)对应英语音节首辅音丛时,相对来说不易察觉到中间的元音V_(x)。另一方面,单就被试在V_(x)为0毫秒条件下的表现而言,其幻听到元音的概率低于Dupoux et al.(1999)实验中日语被试的相应概率,同时又略高于该实验中法语被试的相应概率。这似乎说明,被试的粤语和英语两种语言的音位配列规律存在相互作用,同时影响着被试对辅音间元音的感知。

摘要：高阶拓扑绝缘体展现出新奇的体-边对应关系,即d维n阶拓扑绝缘体具有(d-n)维拓扑保护的边界态.近年来,高阶拓扑绝缘体的相关物理概念已经被拓展到光子晶体、声子晶体等体系中.本文着重讨论声波高阶拓扑绝缘体的边界态在波调控中的具体应用.作者利用原胞的镜像对称性和滑移对称性,设计出一种拓扑非平庸的三维声子晶体.该声子晶体的体能带可由非平庸的量子化体极化表征,从而在不同维度的边界上存在拓扑保护的二维表面态、一维棱态、零维角态.作者对二维表面态和一维棱态加以利用,在实验上实现了拓扑边界态主导的声波在不同维度上的传播操控.具体来说,通过设计二维表面态的色散的设计,实现了声波的负折射;通过利用不同方向上的一维棱态传输,实现了三维里的声干涉.这些结果展示了高阶拓扑绝缘体在操控波传播方面具有独特的应用前景.

摘要：Overseas research has shown that achievement emotions have direct relationships with ＂achievement outcome＂ and＂achievement activities＂. The purpose of the present study aimed to compare the relationships betweenachievement emotions, motivation, and language learning strategies of high, mid and low achievers in Englishlanguage learning at an international university in a southern province in China. Quantitative data were collectedthrough a questionnaire survey of 74 （16 males, 58 females） TESL major students. Results indicated that studentsin general experienced more positive than negative achievement emotions; more intrinsically rather thanextrinsically motivated to learn English; and quite frequently used a variety of learning strategies to overcome theirlearning difficulties. However, Year Four low-achievers experienced more negative achievement emotions. Theyseldom used metacognitive, affective and social learning strategies, and they had lower degrees of intrinsicmotivation. Implications for institutional support for at risk students are discussed.

摘要：Tourism has been a fast growing industry in the world in the past decade. However, research that investigates the effectiveness of outdoor ads targeting to tourists has far lagged behind. This study aims to assess the awareness of outdoor ads and to provide insight into effective advertising that target tourists. Pedestrians intercepted in downtown hong kong were surveyed using a questionnaire and quota sampling. They were presented with images of seven outdoor advertisements currently displayed in the neighborhood and their recall and impressions of the ads were surveyed. The survey sampled 465 local residents and tourists aged 15 and above. Among the tourists, the awareness of the seven ads ranged from 19 to 49 percent with an average 30 percent. They displayed more positive perceptions of outdoor advertising than the locals, but had lower awareness. Practical suggestions for outdoor advertisers targeting tourists are proposed.

摘要：As the most powerful nation in the world, the U. S. presidential election campaign drew a lot of attention from the media around the world. This study examines how party-orientation and market-orientation newspapers in China presented 2008 U. S. presidential election campaign to their audience, and how the news serve for the reproduction of domestic dominated ideology and safeguarding domestic political needs. It adopted content analysis and textual analysis as research methods. The results show that Party newspaper tends to serve domestic political ideology, while market-oriented newspapers showed mixed attitude toward political demand. Although market newspapers, out of the concern of political safety, employed some tactic to comply with the demand of dominated ideology to some extent, their cooperation was limited since their main purpose was commercial success and their presentation even destroy the aim of linkage politics for the reasons include acquiring market profit and/or pursuit of professional value. This study is a positive effort to make up the current research gap of studies on international news in Chinese media.

摘要：This paper proposes new ways to understand the sense of universality in music through a reflection and analysis of George Crumb"s Black Angels (Images I): Thirteen Images from the Dark Land, one of the defining musical expressions of the Vietnam War era. It centers on an analysis of the relationship of the body/self to an "ecology of war" produced through Crumb"s music that renders these selves indistinct within this musical geography. The selves that inhabit Black Angels could be that of anybody in particular since Crumb seeks to invoke in his music the primeval experience of terror that inhabits in all of us as the inheritors of mankind"s violence. This sense of the universal militates against the desirable qualities of popular music that rely on the production of autonomous and singular selves that make the distinction between enemy and friend possible and distinct. We focus on Crumb"s use of archaisms, his construction of time in this piece, and the author"s overall purpose to invoke a time of war rather than to reflect the conditions of war, in order to delineate the contours of the universal time and space producing the undifferentiated primeval self of war. We conclude that although Crumb"s rejection of the national self deprives the piece of a salient place in the popular cannon of the war, it has left an intellectual legacy on the times of the Vietnam War that deserves to be preserved.