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151.
152.
A theory of definitions which places the eliminability and conservativeness requirements on definitions is usually called the standard theory. We examine a persistent myth which credits this theory to Le?niewski, a Polish logician. After a brief survey of its origins, we show that the myth is highly dubious. First, no place in Le?niewski's published or unpublished work is known where the standard conditions are discussed. Second, Le?niewski's own logical theories allow for creative definitions. Third, Le?niewski's celebrated ‘rules of definition’ lay merely syntactical restrictions on the form of definitions: they do not provide definitions with such meta-theoretical requirements as eliminability or conservativeness. On the positive side, we point out that among the Polish logicians, in the 1920s and 1930s, a study of these meta-theoretical conditions is more readily found in the works of ?ukasiewicz and Ajdukiewicz.  相似文献   
153.
Abstract

Pituitary-adrenal axis was studied in terms of Type A behaviour, hostility and vital exhaustion among 69 healthy middle-aged men. The results showed that psychological factors could explain a significant proportion of the biologically manipulated responses of HPA axis, but they worked in different ways. Type A behaviour was related to a high level of mean basal ACTH and a low level of cortisol response to ACTH stimulation after dexamethasone suppression; hostility was related to a high level of mean basal cortisol and a high cortisol in cortisol/ACTH ratio, while vital exhaustion was characterized by a low level of mean basal ACTH and a decreased ACTH in relation to cortisol. The adrenocortical patterns, i.e. a high ACTH-low cortisol; a high cortisol; and a low ACTH-low mean basal cortisol, as related to Type A behaviour, hostility and exhaustion, respectively, are in line with the traditional physiological stress model and suggest that different adrenocortical responses might be able to identify different mental stress processes. Sense of control has been suggested to be a key concept for psychological understanding of this finding.  相似文献   
154.
Single-crystal (0 0 0 1) GaN samples have been deformed with a Vickers indenter at room temperature using loads in the range from 0.02 to 4.90 N. Dislocations and cracks at the indentations were examined by means of scanning electron microscopy, cathodoluminescence, light microscopy and transmission electron microscopy. Geometrical relations could be found between the dislocation arrangement, cracks and the orientation of the indenter. The orientation of the indenter has only a slight effect on the dislocation pattern, but the crack system is predominantly determined by the symmetry and the orientation of the indenter.  相似文献   
155.
This article describes a design strategy deployed in developing ultra-ductile Mg alloys based on a microalloying concept, which aims to restrict grain growth considerably during alloy casting and forming. We discuss the efficiency of the design approach, and evaluate the resulting microstructural and mechanical properties. After processing, the so-designed alloys ZQCa3 (Mg–3Zn–0.5Ag–0.25Ca–0.15Mn, in wt.%) and ZKQCa3 (Mg–3Zn–0.5Zr–0.5Ag–0.25Ca–0.15Mn, in wt.%) reveal very fine grains (<10 µm), high ductility (elongation to fracture of up to 30%) at moderate strength or high strength (ultimate tensile strength of up to 350 MPa) at reasonable ductility. These properties are explained based on thermodynamic modelling, microstructure analysis including transmission electron microscopy studies, and microstructural and mechanical testing after annealing, and are compared to a related commercial alloy (ZK31).  相似文献   
156.
Abstract

Vertigo and dizziness may cause considerable discomfort and feelings of uncertainty. It is no surprise that vertigo is the most disabling symptom in Menière's disease, an inner ear disorder. The other two cardinal symptoms are tinnitus and hearing impairment. In this study, one severely disabled woman was treated with a cognitive-behavioural treatment comprising, among other components, relaxation training, stabilization of gaze, cognitive restructuring and behavioural task setting. The patient responded well to the treatment, during which her vertigo attacks disappeared. During the follow-up period, she experienced vertigo attacks again, but after two booster sessions the vertigo attacks vanished for the rest of the follow-up period. The results are further discussed.  相似文献   
157.
ABSTRACT

This study aimed to test the cognitive and affective benefits gained through the provision of educational materials at workstations in the Wilhelma Zoo in Stuttgart, Germany. Structured learning materials were developed for use with visiting school groups. The materials focused on the adaptations of 6 selected groups of bird species and were organized as a self-guided learning environment (workstations). The value of the materials was assessed in terms of cognitive (learning and retention) and emotional (interest, well-being, boredom, anxiety, contentedness) variables. The authors measured prior knowledge (1 week before the zoo visit), learning effect (1 week after the visit), and retention (8 to 9 weeks later). A total of 103 students (6th graders aged between 11–12 years) participated in the study, 77 receiving a treatment about adaptations in bird species and 26 receiving a treatment about reptiles which served as a control. Students had similar prior knowledge, but 1 week later students receiving the bird unit scored significantly better and this persisted into retention. Girls achieved higher scores than boys, both 1 week and 8 to 9 weeks after the visit. Surprisingly, students in the control group reported higher interest, well-being and contentedness, and lower boredom than those in the treatment group.  相似文献   
158.
The tendency of participants to “remember” the stopping point of an event as being farther along in the direction of motion has been a topic of study for about 30 years. The purpose of the present experiment was to test the influence of two factors on motion extrapolation: (1) The involvement of participants in the action, and (2) their expertise in the domain of automobile driving. Participants viewed real driving scenes from the driver's point of view. They were divided into four groups depending upon their involvement in the action (more or less active) and their driving experience (inexperienced or experienced). In order to get half of the participants involved in the driving situation, they had to use a steering wheel to follow the contour of the road. The results showed that both of these factors increased motion extrapolation. The discussion deals with how the interrelationships between real road scenes, expertise, and action-related knowledge affect motion extrapolation.  相似文献   
159.
Over the last few decades, increased flexibility and lack of stability in employment has made job insecurity a work stressor that affects more and more employees. Since worrying about potential job loss (quantitative job insecurity) or possible loss of valued job features (qualitative job insecurity) constitutes a subjective perception, it has been claimed that personality factors may be decisive for job insecurity perceptions. Furthermore, the perception of a stressor, in this case job insecurity, could be argued to be dependent on appraisals of available coping resources. This study investigates whether core self-evaluations predict job insecurity perceptions, and whether coping mediates this relationship, in a two-wave data set from a Swedish sample of white-collar workers (N = 425). The results show that core self-evaluations had a negative total effect on both qualitative and quantitative job insecurity. Core self-evaluations were positively related to problem-focused coping but not to emotion-focused coping. However, there was no mediating effect of coping style on the association between core self-evaluations and job insecurity.  相似文献   
160.
Book Review     
Abstract

Yukl, G.A. (1989). Leadership in organizations (2nd ed.), Prentice Hall International Editions. ISBN 0-1352-7169-X. £20.95.  相似文献   
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