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211.

We have found stable icosahedral (i) phases in alloys with nominal compositions around Al 72 Pd 17 Ru 11 and Al 72 Pd 17 Os 11 . They display very sharp X-ray diffraction peaks, indicating high structural order as in other Al-based i-phases such as i-(Al-Pd-TM) (transition metal TM = Mn or Re) and i-(Al-Cu-TM) (TM =Fe, Ru or Os). The i phases are formed via peritectic reaction and, upon heating, they transform into a mixture of a liquid and the 1/0 cubic approximant phase. The electrical resistivity of the i phases was measured in a wide temperature range from 14K to above their melting points and a reversible change of the resistivity across the melting point has been observed in situ for the first time.  相似文献   
212.
Research has shown that performing visual search while maintaining representations in visual working memory displaces up to one object's worth of information from memory. This memory displacement has previously been attributed to a nonspecific disruption of the memory representation by the mere presentation of the visual search array, and the goal of the present study was to determine whether it instead reflects the use of visual working memory in the actual search process. The first hypothesis tested was that working memory displacement occurs because observers preemptively discard about an object's worth of information from visual working memory in anticipation of performing visual search. Second, we tested the hypothesis that on target absent trials no information is displaced from visual working memory because no target is entered into memory when search is completed. Finally, we tested whether visual working memory displacement is due to the need to select a response to the search array. The findings rule out these alternative explanations. The present study supports the hypothesis that change-detection performance is impaired when a search array appears during the retention interval due to nonspecific disruption or masking.  相似文献   
213.
This paper considers implications to psychoanalytic psychotherapy of the British Government's decision to implement a patient choice agenda for state‐funded mental health services in England and Wales. It places the patient choice agenda in the context of consumerist society and argues that the complex nature of psychoanalytic psychotherapy leaves it more vulnerable than other psychological therapy modalities to compete in the current reality of ‘consumer’‐led public mental health, which, in turn reflects a profoundly changed social context from that to which psychoanalysis traces its roots. Unless psychoanalytic clinicians recognize and find ways to adjust to this context they will jeopardize the survival of psychoanalytic psychotherapy in an increasingly market‐orientated model of mental healthcare provision in the public sector, eager to promote more ‘consumer friendly’ psychological therapy models.  相似文献   
214.
In this paper, we challenge the usual argument which says that competition is a fair mechanism because it ranks individuals according to their relative preferences between effort and leisure. This argument, we claim, is very insufficient as a justification of fairness in competition, and we show that it does not stand up to scrutiny once various dynamic aspects of competition are taken into account. Once the sequential unfolding of competition is taken into account, competition turns out to be unfair even if the usual fairness argument is upheld. We distinguish between two notions of fairness, which we call U-fairness, where U stands for the usual fairness notion, and S-fairness, where S stands for the sequential aspect of competition. The sequential unfairness of competition, we argue, comprises two usually neglected aspects connected with losses of freedom: first of all, there is an eclipse of preferences in the sense that even perfectly calculating competitors do not carry out a trade-off between effort and ranking; and second, competitive dynamics leads to single-mindedness because the constraints on the competitors choices always operate in the sense of increased competitiveness and, therefore, in the direction of an increased effort requirements. We argue (1) that competition is S-unfair even if it is U-fair, (2) that as S-unfairness increases, the ethical relevance of U-fairness itself vanishes, so that (3) by focusing as they usually do on U-fairness alone, economists neglect a deeper aspect of unfairness.  相似文献   
215.
Five experiments on honeybees examined how the learning of a second task interferes with what was previously learned. Free flying bees were tested for landmark-based memory in variations on a paradigm of retroactive interference. Bees first learned Task 1, were tested on Task 1 (Test 1), then learned Task 2, and were tested again on Task 1 (Test 2). A 60-min delay (waiting in a box) before Test 2 caused no performance decrements. If the two tasks had conflicting response requirements, (e.g., target right of a green landmark in Task 1 and left of a blue landmark in Task 2), then a strong decrement on Test 2 was found (retroactive interference effect). When response competition was minimised during training or testing, however, the decrement on Test 2 was small or nonexistent. The results implicate response competition as a major contributor to the retroactive interference effect. The honeybee seems to hold on to memories; new memories do not wipe out old ones.  相似文献   
216.
We present data from four experiments using cross-modal priming to examine the effects of competitor environment on lexical activation during the time course of the perception of a spoken word. The research is conducted from the perspective of a distributed model of speech perception and lexical representation, which focuses on activation at the level of lexical content. In this model, the strength of competition between simultaneously active lexical items depends on the degree of coherence between their distributed semantic and phonological representations. Consistent with this model, interference effects are more complete when the purely semantic aspects of these coactive representations are probed (using semantic priming) than when phonological aspects are probed as well (using repetition priming).  相似文献   
217.
Morrison  Maria Michelle  Shaffer  David R. 《Sex roles》2003,49(5-6):265-275
In an initial experiment, men and women with varied gender-role orientations evaluated gender-stereotyped and nonstereotyped advertisements for gendered products that are actually used by both sexes. Consistent with a gender-role congruence model of advertising effectiveness, traditional participants (masculine men; feminine women) responded more favorably to traditional (i.e., gender-stereotyped) than to nontraditional advertisements, whereas nontraditional participants (androgynous individuals; feminine men; masculine women) reacted somewhat more favorably to the nontraditional advertisements. Experiment 2 revealed that when encouraged to self reference, traditional participants became much more responsive to nontraditional advertisements, even more so than were the nontraditional participants. Practical implications of these results are discussed.  相似文献   
218.
结果冲突与作业难度对双重作业绩效的影响   总被引:4,自引:2,他引:2  
葛列众  朱祖祥 《心理学报》1995,28(3):247-253
运用单作业和双作业操作探讨结果冲突与作业难度对双重作业绩效的影响。结果表明:(1)信息干扰对双作业操作有着明显的影响。信息干扰越大,结果冲突效应越大,双作业操作绩效越差。(2)作业难度对双作业绩效有明显影响。作业难度越大,双作业操作绩效越差。根据实验结果,本研究提出了双因素假设:信息干扰和资源竞争是影响双作业操作绩效的两个主要因素。  相似文献   
219.
McLean (1992) presented significant data showing that the occurrence of behavioral contrast in a multiple schedule was correlated with shifts in the frequency of reinforcers from a second source between components of the schedule, and interpreted his results as showing that contrast was due to changes in the degree of response competition within the constant component of the multiple schedule. Reanalysis of his data shows that there was an effect of reinforcement in the alternative component of the schedule independent of the shifts in reinforcers between components. Thus, the effect of relative rate of reinforcement cannot be ascribed, at least entirely, to the mechanisms proposed by the behavioral competition theory of contrast.  相似文献   
220.
Acquisition and maintenance of trusting behavior   总被引:3,自引:3,他引:0       下载免费PDF全文
This study determined whether a two-person exchange situation contained natural contingencies for trusting behavior or whether external contingencies were necessary. Pairs of college students worked matching-to-sample problems for money. On each trial there was one problem and the subjects determined which of them would solve it. Trusting behavior was defined as an increase in the number of consecutive problems each subject allowed his partner to work during sessions that also ended with an equitable distribution. Simply, trust was a temporary deviation from equity. A subject could give the problem to the other person (cooperate), or not respond and let the other person take the problem (share). Other possibilities were for both subjects to try to take the problem (complete), or for neither subject to respond and thereby let the person who worked the last problem also work the next one (passive trust). When only four lever pulls were required to distribute a problem (no external contingencies to reach either equity or trust) subjects reached equity, but only minimal trust (strict alternation of single problems) developed in 18 sessions. When 30 or 60 lever pulls were required to distribute a problem (smaller response requirement for passive trust and therefore a contingency for trust), trusting behavior developed after a few sessions (fixed ratio 30) or after several trials of the first session (fixed ratio 60) and it ordinarily expanded gradually to 10 to 15 consecutive problems through passive trust. The aversiveness of the inequity involved in trusting appears to necessitate a contingency for acquisition. Once trust develops, however, this aversiveness is reduced as subjects learn the inequity is only temporary (e.g., once trust was acquired at fixed ratio 60 it was maintained at fixed ratio 4, which would not initially produce it), and the direction of the inequity appears to become of questionable importance (e.g., being behind was alternated over rather than within sessions and usually not in a systematic manner).  相似文献   
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