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121.
神经性厌食症和神经性贪食症是主要的进食障碍症状。进食障碍的影响因素有社会文化因素(例如媒体和同伴的影响)、家庭因素(如困惑和冲突)、消极情绪、低自尊水平和对自身的不满及认知和生物方面的因素等。  相似文献   
122.
Self-esteem is a positive evaluation of oneself that can facilitate optimal functioning. However, little research has focused on its antecedents in sport. Accordingly, we adopted an interactionism perspective and proposed that gratitude, a dispositional factor, will enhance an athlete's self-esteem and affective trust in coach, a situational factor, will strengthen such a positive effect. Athletes completed measures of gratitude, affective trust in coach, and self-esteem at Time 1 and self-esteem at Time 2 after 6 months. Results showed that athletes with higher levels of gratitude increased their self-esteem over time when they had higher affective trust in their coaches.  相似文献   
123.
The “Learn to Think” (LTT) Intervention Program was developed for raising thinking abilities of primary and secondary school students. It has been implemented in more than 300 schools, and more than 200,000 students took part in the experiment over a 10‐year span. Several longitudinal intervention studies showed that LTT could promote the development of students' thinking ability, learning motivation, and learning strategy as well as raise academic performance in primary schools. This article describes a study of the influence and the delayed effects of LTT on the scientific creativity of secondary school students. One hundred and seven students were selected from a secondary school, 54 of them participated in the LTT every 2 weeks and the rest had not. The intervention lasted 2 years, and the delayed effect was explored half a year after terminating the intervention. The Scientific Creativity Test for Secondary School Students was used four times from pre‐test to delayed post‐test. The results indicated that the LTT did promote the development of scientific creativity of secondary school students, and the effects on the scientific creativity were not necessarily immediate, but tended to be long‐lasting.  相似文献   
124.
The purpose of this study was to investigate the differences of knee concentric and eccentric strength and impact related knee biomechanics between jumpers and non-jumpers during step-off landing tasks. Ten male college swimming athletes (non-jumpers) and 10 track and volleyball athletes (jumpers) were recruited to participate in two test sessions: a muscle strength testing session of concentric and eccentric extension for dominant knee joint at 60 °/s and 180 °/s and a landing testing session. The participants performed five trials of step-off landing in each of four conditions: soft and stiff landing from 0.4 m and 0.6 m landing heights. The three-dimensional kinematics and ground reaction force were recorded simultaneously during step-off landing conditions. The results showed that the jumpers had significantly greater peak knee eccentric extension and concentric flexion torques compared to the non-jumpers. No significant group effects were found for peak vertical ground reaction force and knee range of motion during landing. The jumpers had significantly greater knee contact flexion angle, maximum knee flexion angle and initial knee extension moment compared to the non-jumpers. These results suggest that these athletes adopted a favorable impact attenuation strategy that is related to the greater knee eccentric muscle strength and training.  相似文献   
125.
It is argued that the emotional feeling comprises the following two emotional qualia. (1) A nucleus feeling or primary emotional quale, which is the phenomenological counterpart of the end product of appraisal by the central nervous system. (2) The experience of being urged to emotion-related reflection or secondary emotional quale, which is the phenomenological counterpart of the brain's decision to inhibit pre-programmed emotional behaviour, and to initiate emotion-related reflections. Different brain modules regulate these two qualia, and thus each can be experienced independently of the other. The primary emotional quale is related to activation of the amygdala, it is emotion specific, and neutral with respect to affect. The secondary emotional quale is related to activation of the orbito-prefrontal cortex (O-PFC), and includes affective aspects.

It is argued that emotional behaviour is regulated by the following three neural mechanisms, two of which two are directly related to the two qualia. (1) An evolutionary ancient system (amygdala-system), which comprises the amygdalae and subcortical nuclei, and which activates pre-programmed emotional behaviour. (2) An evolutionary recent system (PFC-system), comprising the prefrontal cortex, which inhibits pre-programmed emotional behaviour, activates emotional reflection, generates and evaluates behavioural alternatives. In contrast to the pre-programmed behaviour, the behavioural alternatives are more likely to serve long-term goals. (3) A default mechanism, which gives rise to default (i.e., “just do something”) behaviour. The first two systems are mutually competitive, while the third mechanism takes over if either the competition between the first two mechanisms, or the decision process of the PFC-system, takes too long. This default mechanism involves the function of the medial-prefrontal cortex (M-PFC).  相似文献   
126.
Although the state space approach for estimating multilevel regression models has been well established for decades in the time series literature, it does not receive much attention from educational and psychological researchers. In this article, we (a) introduce the state space approach for estimating multilevel regression models and (b) extend the state space approach for estimating multilevel factor models. A brief outline of the state space formulation is provided and then state space forms for univariate and multivariate multilevel regression models, and a multilevel confirmatory factor model, are illustrated. The utility of the state space approach is demonstrated with either a simulated or real example for each multilevel model. It is concluded that the results from the state space approach are essentially identical to those from specialized multilevel regression modeling and structural equation modeling software. More importantly, the state space approach offers researchers a computationally more efficient alternative to fit multilevel regression models with a large number of Level 1 units within each Level 2 unit or a large number of observations on each subject in a longitudinal study.  相似文献   
127.
A phase transition of MgS under high pressure is investigated using a first-principles method. It is found from energy-volume calculations that the rock-salt (B1) phase of MgS transforms into a FeSi-type (B28) phase at 143?GPa. The calculated ground-state parameters in the B1 phase are in excellent agreement with available experimental and theoretical data. Ab initio phonon calculations are also performed to investigate the structural behaviour of MgS under high pressure. An unstable transverse acoustic mode and a phase transition from B1 to B28 phase at ~143.7?GPa driven by this soft mode are predicted. The B28 structure of MgS is stable up to 350?GPa according to lattice dynamics calculations.  相似文献   
128.

High-resolution grazing-incidence parallel-beam powder diffraction has been used to detect the subsurface damage below alumina surfaces subjected to polishing with cerium oxide or diamond. Despite very significant evolution of the surface morphology, no changes in the subsurface strains were observed over a 20min period of polishing with ceria. For both polishing materials, the variation with angle in the full-width at half-height maximum was successfully modelled by a strain distribution that fell exponentially with increasing depth. Although the surface amplitude and depth dependence parameter are coupled, we have been able to place upper limits on the depth to which the damage extends. Under realistic assumptions, the depth of damage induced by 1µm diamond paste is comparable with that from 3µm ceria polish.  相似文献   
129.

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.  相似文献   
130.
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