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1.
INTRODUCTION With the continuous development of science and technology, especially the rapid progress of electronic industry and micromachine, microparts are needed more and more, and their technical requirements are higher and higher (Geiger et al., 1994; 1996; Geiger and Engel, 2002). However, traditional processing technologies, like cutting, etc., do not meet these requirements. Traditional plastic forming technology has merits like high production rate, excellent me-chanical proper…  相似文献   

2.
Prelinguistic babbling often seems remarkably speech-like, not because it has recognizable words but because it seems to have adult-like prosody. To quantify this impression, we compared disyllabic sequences from five infants and five adults in terms of the use of frequency, intensity, and duration to mark stress. Significantly larger values for the three acoustic variables were observed on stressed than on unstressed syllables independent of syllable position for both groups. Adults showed the correlates of utterance final syllables--lower f0, lower intensity, and longer duration; infants showed only decrease in intensity. Ratios for stressed to unstressed syllables and participation of the three variables in stress production in individual disyllables were highly similar in both groups. No bias toward the English lexical trochaic stress pattern was observed. We conclude that infants in English environments produce adult-like stress patterns before they produce lexical items, which specify stress. Acoustic and perceptual analyses are used to explore stress marking by prelinguistic infants in an English language environment. Results show that infants employ the three acoustic correlates of stress in individual syllables in a manner largely similar to that of adult speakers, although they do not show second-syllable declination effects or an English language trochaic stress bias.  相似文献   

3.
Solving arithmetic word problems such as “Mary has 25 marbles. She has 5 more marbles than John. How many marbles does John have?”, in which the relational term (more than) interferes with the arithmetic operation (subtraction), relies in part on the ability to inhibit an overlearned ‘add if more or subtract if less’ heuristic in children, adolescents and adults. Here, we used a negative priming (NP) paradigm to investigate whether experts in mathematics need to inhibit this heuristic when solving this type of arithmetic word problem. We found NP effects in experts in mathematics, but with a smaller amplitude than those in non-experts (N = 40). We replicate these results in a second experiment (N = 62) in which we matched experts and non-experts on general intelligence and inhibitory control ability. This suggests that experts also need to inhibit the ‘add if more or subtract if less’ heuristic to solve such problems but were more efficient at inhibiting the heuristic than non-experts.  相似文献   

4.
A career workshop that applies models of the Cognitive Information Processing Approach (Sampson, Reardon, Peterson, &; Lenz, 2004) and incorporates critical ingredients (Brown and Ryan Krane, 2000) to promote the career choice readiness of young adolescents was developed and evaluated with 334 Swiss students in seventh grade applying a Solomon four group design with a three-month follow-up. Participants significantly increased their performance in terms of career decidedness, career planning, career exploration, and vocational identity. Implications for evaluation research and counselling practice are presented.  相似文献   

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The role of psychological interpretations in the relationship between low socioeconomic status (SES) and physiological responses was tested. One hundred high school students (ages 15–19) watched videos of ambiguous and negative life situations, and were interviewed about their interpretations. Lower SES was associated with greater threat interpretations during ambiguous (but not negative) situations and with greater diastolic blood pressure and heart rate reactivity. Threat interpretations partially mediated relationships between SES and reactivity. General life events (e.g., lack of positive life events), rather than specific life events (e.g., exposure to violence), partially explained the relationship between low SES and threat interpretations. Results suggest that the larger social environment helps explain how adolescents approach new social situations, which in turn has implications for adolescent physical health.  相似文献   

7.
Zhu  Huiyuan  Yan  Shaochun  Wu  Jingshuo  Zhang  Zhong  Li  Xiaolin  Liu  Zheng  Ma  Xing  Zhou  Lina  Zhang  Lin  Feng  Mingming  Geng  Yiwei  Zhang  Aixin  Janciauskiene  Sabina  Xu  Aiguo 《Journal of Zhejiang University. Science. B》2021,22(6):512-520
Background: Previous studies have shown that macrophage migration inhibitory factor(MIF) is involved in the pathogenesis of asthma. This study aimed to investigate whether serum MIF reflects a therapeutic response in allergic asthma.Methods: We enrolled 30 asthmatic patients with mild-to-moderate exacerbations and 20 healthy controls, analyzing the parameter levels of serum MIF, serum total immunoglobulin E(tIgE), peripheral blood eosinophil percentage(EOS%), and fractional exhaled nitric oxide(FeNO). Lung function indices were used to identify disease severity and therapeutic response.Results: Our study showed that all measured parameters in patients were at higher levels than those of controls. After one week of treatment, most parameter levels decreased significantly except for serum tIgE. Furthermore, we found that serum MIF positively correlated with EOS% as well as FeNO, but negatively correlated with lung function indices. Receiver operator characteristic(ROC) curve analysis indicated that among the parameters, serum MIF exhibited a higher capacity to evaluate therapeutic response. The area under the curve(AUC) of MIF was 0.931, with a sensitivity of 0.967 and a specificity of 0.800.Conclusions: Our results suggested that serum MIF may serve as a potential biomarker for evaluating therapeutic response in allergic asthma with mild-to-moderate exacerbations.  相似文献   

8.
This paper reports on a small-scale exploratory study which piloted the use of sociometric techniques with a class group of adolescents attending a day special school for pupils experiencing severe learning difficulties (SLD). The aim of the study was to investigate peer relationships and aspects of friendships among this population. The results indicated that the relationships and friendships of these adolescents appeared genuine and to be of significance. Statistical analysis and observation of actual behaviour indicated that choices made were stable and valid and appeared to be based on similar criteria of acceptability to 'mainstream' choices. The majority of adolescents were able to provide rational justifications for their choices and some were able to evaluate the relationship of others with him or her. The implications of the results are discussed with reference to a continuing trend towards inclusion.  相似文献   

9.
According to Cognitive Load Theory, learning material should be designed in a way to decrease unnecessary demands on working memory (WM). However, recent research has shown that additional demands on WM caused by less legible texts lead to better learning outcomes. This so-called disfluency effect can be assumed as a metacognitive regulation process during which learners assign their cognitive resources depending on the perceived difficulty of a cognitive task. Increasing the perceived difficulty associated with a cognitive task stimulates deeper processing and a more analytic and elaborative reasoning. Yet there are studies which could not replicate the disfluency effect indicating that disfluency might be beneficial only for learners with particular learner characteristics. Additional demands on working memory caused by disfluent texts are possibly just usable by learners with a high working memory capacity. Therefore the present study investigated the aptitude-treatment-interaction between working memory capacity and disfluency. Learning outcomes were measured by means of a retention, a comprehension, and a transfer test. Moreover, the three types of cognitive load (intrinsic, extraneous, and germane) were assessed. The results revealed significant aptitude-treatment-interaction effects with respect to retention and comprehension. Working memory capacity had a significant influence only in the disfluency condition: The higher the working memory capacity, the better the retention and comprehension performance in the disfluency condition. No effects were found with respect to transfer or cognitive load. Thus, the role of metacognitive regulation and its possible effects on cognitive load need further investigation.  相似文献   

10.
Event-related potential (ERP) correlates of item and source memory were assessed in 18 children (7-8 years), 20 adolescents (13-14 years), and 20 adults (20-29 years) performing a continuous recognition memory task with object and nonobject stimuli. Memory performance increased with age and was particularly low for source memory in children. The ERP difference between first presentations of objects and nonobjects, reflecting generic novelty processing, showed only small developmental changes. Regarding item memory, adults showed the putative ERP correlates of familiarity and recollection, whereas ERP effects in children and adolescents suggested a strong reliance on recollection. ERP correlates of source memory refined with age, suggesting maturation of strategic recollection between childhood and adolescence and the development of postretrieval control until adulthood.  相似文献   

11.
The purpose of this study was to examine the effects of the Demand Control Model (DCM) and the Effort Reward Imbalance Model (ERIM) on academic burnout for Korean students. Specifically, this study identified the effects of the predictor variables based on DCM and ERIM (i.e., demand, control, effort, reward, Demand Control Ratio, Effort Reward Ratio) on academic burnout. Participants were 1,530 elementary, middle, and high school students and multivariate multiple regression analysis was used. Results indicated that the variables of ERIM (i.e., effort, reward, Effort Reward Ratio) were more influential predictors than the variables of the DCM (i.e., demand, control, Demand Control Ratio). Implications and limitations are discussed.  相似文献   

12.
This longitudinal study examined the link between multiple aspects of early non-parental care and internalizing and externalizing behaviour at 30 months of age. We also examined whether this link was mediated by children's inhibitory control and moderated by early temperamental negative affectivity. Participants were 193 mothers and their infants (91 girls; 79 firstborn). Negative affectivity was measured with a temperament questionnaire at 3 months of age. Information on non-parental care (i.e. centre-based care, number of hours, number of concurrent arrangements, long-term instability of care and age of entry) was obtained through monthly maternal interviews across the first year of life. At 30 months of age, toddlers’ inhibitory control was measured with observational tasks, and behaviour problem questionnaires were completed by the mothers and the caregivers. The mediation model was not supported. Greater observed inhibitory control, however, was related to less caregiver-reported internalizing and externalizing behaviour. Furthermore, negative affectivity moderated the effect of early non-parental care on behaviour problems. Non-parental care was unrelated to behaviour problems in toddlers who displayed low or mean levels of negative affectivity as infants. For infants high in negativity, however, centre-based care was associated with higher mother-rated internalizing and externalizing problems. In sum, the link between aspects of non-parental care during the first year of life and toddlers’ behaviour problems was not mediated through inhibitory control. Instead, inhibitory control and non-parental care, in conjunction with negative affectivity, appear to be two independent predictors of toddlers’ internalizing and externalizing behaviour.  相似文献   

13.
OBJECTIVE: This study aimed to examine the level of sexual abuse knowledge and self-protection skills in a sample of female Chinese adolescents with mild mental retardation. It was hypothesized that the participants would exhibit impoverished knowledge on sexual abuse and related self-protection strategies. METHOD: A total of 77 female Chinese adolescents aged from 11 to 15 years old who met the inclusion criterion of the study were recruited from four special schools for mental retardation. The Chinese versions of the Personal Safety Questionnaire and the "What If' Situation Test (Wurtele, 1990) were administered orally to the participants during individual interviews. RESULTS: Participants were more able to accurately recognize inappropriate than appropriate touches and sexual requests, and possessed limited information about sexual abuse. They were also inadequate in protecting themselves against sexual abuse, and had the most difficulty in reporting the sexually abusive incident and characteristics of the offender. Regression analyses also showed that their sexual abuse knowledge was the best predictor for self-protection skills. CONCLUSION: The present findings provided strong cross-cultural support to previous Western studies that found females with mild mental retardation of high risk to sexual abuse and in need of specially designed prevention program to enhance their competency against sexual victimization and exploitation. With modification and refinement, measurement scales used in the Western general population could be extended to Chinese adolescents with mental retardation. Suggestions on the design of the sexual abuse prevention programs, limitations of the present study, and recommendations for future studies were also discussed.  相似文献   

14.
Numerous studies have suggested that academic stress has negative impact on adolescents’ psychological function, few of those studies, however, considered whether and how the impact of stress on adolescents’ emotional states is moderated by corresponding regulation. This study aimed to examine the fluctuation of emotional states before and after the mid-term examination and the influence of different emotional regulatory strategies. In the present study, 72 adolescents aged 12–18 reported their emotional states and corresponding regulation before and after mid-term examination up to six times over a period of two weeks. Results showed that: (a) On the sampling day, the participants reported increasingly emotional states as time went by. Improvement of adolescents’ daily emotional states was more significant after the mid-term examination. Participants reported decreasingly positive emotional states and increasingly negative ones as time went by before mid-term examination. (b) Adolescents who used down-regulation at a certain sampling moment reported more pleasant emotional states at the subsequent sampling moment than those who used up-regulation. Adolescents who used more up-regulation in a negative emotional event reported more negative emotional states at the subsequent sampling moment after the mid-term examination.  相似文献   

15.
OBJECTIVE: The purpose of the current study was to investigate the independent effects of different treatment elements on a number of secondary problems related to childhood and adolescent sexual abuse, as well as investigate a number of different moderators of treatment effectiveness. METHOD: Twenty-eight studies that provided treatment outcome results for children and adolescents who had been sexually abused were included in the meta-analysis. Different aspects of psychological treatment, such as specific treatment modalities (individual, cognitive-behavioral, etc.) or secondary problems (behavior problems, psychological distress, etc.) were investigated. RESULTS: The overall mean weighted effect size for the meta-analysis was d=.72 (SE=.02). The results indicate that psychological treatment after childhood or adolescent sexual abuse tended to result in better outcomes than no treatment. There was significant heterogeneity in the effectiveness of the various psychological treatment elements. Play therapy seemed to be the most effective treatment for social functioning, whereas cognitive-behavioral, abuse-specific, and supportive therapy in either group or individual formats was most effective for behavior problems. Cognitive-behavioral, family, and individual therapy seemed to be the most effective for psychological distress, and abuse-specific, cognitive-behavioral, and group therapy appeared to be the most effective for low self-concept. CONCLUSIONS: The choice of therapy modality should depend on the child's main presenting secondary problem. Further research should be conducted investigating other possible moderators and secondary problem outcomes.  相似文献   

16.
为证实脐血能否与骨髓一样有促进骨愈合的作用,72只新西兰兔随机被分为兔脐血、人脐血、对照及血肿组。病理组织学及电镜观察结果显示:血肿组较对照组愈合好,两脐血组间无明显差异,愈合质量均比血肿组好。结论:脐血与骨髓一样有促进骨折愈合作用。  相似文献   

17.
Self-concept and ego development, two intertwined aspects of self-indicating well-being and social-cognitive maturation, respectively, were examined in a representative sample of deaf adolescents of normal intelligence (N = 68), using translated and adapted versions of Harter's (1988, Manual for the self-perception profile for adolescents. Denver, CO: University of Denver) multidimensional measure of self-concept and Loevinger's (1998, Technical foundations for measuring ego development. Mahwah, NJ: Lawrence Erlbaum) measure of ego development. Compared to hearing norm groups, deaf adolescents showed lower levels of self-perceived social acceptance, close friendships and ego development and higher physical appearance. Hierarchical multiple regression analyses controlling for sociodemographic variables showed positive associations of global self-worth with support for signing during childhood and quality of parent-child communication and of ego development with attending a regular school. Cluster analysis identified three social competence profiles: uniformly low competence, uniformly high competence, and low social acceptance with high physical appearance. Cluster membership was associated with school type, ego development, and (past) neurological disorder. The results are discussed in reference to interventions aimed at the well-being of deaf youth.  相似文献   

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This study explores whether activation and inhibition word processes contribute to the characteristic speed deficits found in transparent orthographies (Wimmer, Appl Psycholinguist 14:1–33, 1993). A second and fourth grade sample of normal school readers and dyslexic school readers participated in a lexical decision task. Words were manipulated according to two factors: word frequency (high vs. low) and syllable frequency (high vs. low). It has been repeatedly found that words with high-frequency syllables require extra time for deactivating the lexical syllabic neighbors: the so-called inhibitory effect of positional frequency syllable (Carreiras et al., J Mem Lang 32:766–780, 1993). We hypothesized that dyslexic readers would show a stronger inhibitory effect than normal readers because they are slower decoders and they may also be slower at the activation and inhibition of word representations that are competing (i.e., syllabic candidates). Results indicated an interaction between word and syllable frequency (i.e., a strong inhibitory effect was found in the low-frequency word condition). According to our hypothesis, the inhibitory effect size was almost three times bigger in dyslexics than in the normal readers. This difference shows an alteration, not a developmental lag. Interestingly, the inhibitory effect size did not interact with school grade. Thus, reading experience did not impact the lexical processes involved on the inhibitory effect. Our outcomes showed how activation and/or inhibition of lexical processes can contribute to the lack of speed beyond decoding deficit.  相似文献   

20.
碱胁迫对叶片延迟发光的实验研究   总被引:1,自引:0,他引:1  
选用绿宝石喜林芧叶片为材料,用BPCL型微弱发光测量仪测量了叶片经高浓度NaOH溶液处理后的延迟发光情况。结果发现:同一个叶片随着处理时间的延长,其延迟发光最初值和最后100s的光子数都先有一个小幅度的上升,然后又迅速下降;不同的叶片在相同的处理时间下,随着NaOH质量分数的增加,延迟发光最初值和最后100s的光子数都呈现上升的趋势,NaOH质量分数越大,上升得越快,随着处理时间的延长,上升的趋势变得越来越缓,最后各曲线越来越接近,且趋于平稳。整个实验表明,延迟发光可以规律性地反应碱胁迫对叶片的伤害程度,这为生物物理方法测量外界胁迫对叶片的影响提供了参考。  相似文献   

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