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1.
本实验通过试验,对ICP-OES仪器工作条件进行了选择和优化,建立了ICP-OES测定欧盟玩具安全新指令限制第三类物质的17种可迁移元素(铝、锑、砷、钡、硼、镉、铬、钴、铜、铅、锰、汞、镍、硒、锶、锡、锌)的方法。本方法的检出限低,选取的第三类物质:涂层、聚合物、纸张、纺织品、金属、木材等多种材料的平均回收率均在94%~109%。结果显示方法有良好的准确度。  相似文献   
2.
555时基电路在玩具控制应用中占有重要的地位。本文结合作者在高职院校毕业设计以及在中学开展科技发明、教具制作的经验,介绍了555时基电路在玩具设计中的应用范例,介绍了声控、红外控制、位置控制等玩具及教具的设计思路和方法。本文对于玩具设计与制造专业的师生以及玩具设计人员有一定的参考作用。  相似文献   
3.
This study examined different types of longitudinal associations (i.e., directional links and overlapping developmental changes) between children's delinquency and the quality of parent–child relationships from middle childhood to late adolescence. We used 10-wave interview data of 503 boys, their primary caregivers, and their teachers. Our first aim was to unravel the direction of effects between parent–child relationships and children's offending. Cross-lagged panel models revealed bidirectional links over time between poorer quality parent–child relationships and boys' offending across late childhood (age 7–10), early adolescence (age 10–13) and middle adolescence (age 13–16). Second, we examined the associations between mean changes in delinquency, on the one hand, and mean changes in relationship quality, on the other hand. Although parent–child relationships improved during childhood, their quality decreased in early adolescence and remained stable in middle adolescence. Delinquency increased only in middle adolescence. In five out of six models, the slope factors of relationship quality and offending were strongly correlated, indicating that stronger increases in delinquency were associated with stronger decreases in parent–child relationship quality across childhood, early adolescence, and middle adolescence. The discussion focuses on the theoretical implications of these two types of longitudinal associations. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
4.
A handful of prior adoption studies have confirmed that the cross-sectional relationship between child conduct problems and parent–child conflict at least partially originates in the shared environment. However, as the direction of causation between parenting and delinquency remains unclear, this relationship could be better explained by the adolescent's propensity to elicit conflictive parenting, a phenomenon referred to as an evocative gene–environment correlation. In the current study, the authors thus examined the prospective relationship between conduct problems and parent–child conflict in a sample of adoptive families. Participants included 672 adolescents in 405 adoptive families assessed at 2 time points roughly 4 years apart. Results indicated that parent–child conflict predicts the development of conduct problems, whereas conduct problems do not predict increases in parent–child conflict. Such findings suggest that evocative gene–environment correlations are highly unlikely to be an explanation of prior shared environmental effects during adolescence. Moreover, because the adolescents in this study do not share genes with their adoptive parents, the association between conduct problems and parent–child conflict is indicative of shared environmental mediation in particular. Implications of the findings are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
5.
In this study, the authors examined parent-adolescent cortisol associations in 45 families with adolescent children (24 girls; M age = 15.78 years, SD = 1.44 years). Family members’ salivary cortisol levels were measured seven times a day on 2 typical weekdays. Family members provided reports of demographic and health variables, and adolescents rated parent-child relationship characteristics. After accounting for the effects of time of day and relevant demographic and health control variables on cortisol levels, hierarchical linear models indicated the presence of significant covariation over time in mother-adolescent cortisol (i.e., physiological synchrony). Furthermore, moderating tests revealed that mother-adolescent cortisol synchrony was strengthened among dyads characterized by mothers and adolescents spending more time together, and in families rated higher on levels of parent-youth shared activities and parental monitoring or supervision. Analysis of momentary characteristics indicated that maternal presence at the time of cortisol sampling lowered adolescent cortisol levels but did not account for mother-adolescent cortisol synchrony. Within-family physiological synchrony was amplified in momentary contexts of elevated maternal negative affect and elevated adolescent negative affect. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
为了解决磁石玩具耐久性测试中存在的耗时长、效率低、外部干扰多等问题,研制一套基于PLC控制技术的自动测试装置,以实现磁石玩具耐久测试的标准化。介绍了测试标准化的要素及其实现过程,对磁石玩具耐久性测试自动测试装置的结构组成、工作原理、工作过程进行了详细阐述,指出该装置可满足中国、美国、欧盟等玩具安全标准关于磁石玩具测试要求。  相似文献   
7.
This study investigated the ability of a psychosocial prevention program implemented through childbirth education programs to enhance the coparental and couple relationship, parental mental health, the parent-child relationship, and child outcomes. A sample of 169 heterosexual, adult couples expecting their first child was randomized to intervention and control conditions. The intervention families participated in Family Foundations, a series of eight classes delivered before and after birth, which was designed as a universal prevention program (i.e., applicable to all couples, not just those at high risk). Intent-to-treat analyses utilizing data collected from child age 6 months through 3 years indicated significant program effects on parental stress and self-efficacy, coparenting, harsh parenting, and children's emotional adjustment among all families, and maternal depression among cohabiting couples. Among families of boys, program effects were found for child behavior problems and couple relationship quality. These results indicate that a universal prevention approach at the transition to parenthood focused on enhancing family relationships can have a significant and substantial positive impact on parent and child well-being. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
The study examined whether the quality of the adolescent–parent relationship was associated with better diabetes management in adolescents with Type 1 diabetes by decreasing adolescents' extreme peer orientation. Adolescents (n = 252; 46% male and 54% female) aged 10 to 14 years with Type 1 diabetes completed assessments of extreme peer orientation (i.e., tendency to ignore parental advice and diabetes care to fit in with friends), adolescent–parental relationship, and adherence; HbA1c scores indexed metabolic control. Adolescents with higher quality relationships with parents reported less peer orientation and better diabetes care. The mediational model revealed that adolescents' high quality relationships with their parents (mother and father) were associated with better treatment adherence and metabolic control through less peer orientation. It is likely that high quality adolescent–parent relationships may be beneficial to adolescent diabetes management through a healthy balance between peer and parental influence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
9.
Do clinic-referred children and their parents agree on the problems for which treatment is undertaken? The authors asked 381 outpatient-clinic-referred children and their parents to list, independently, the child's target problems. Of the parent-child pairs, 63 % failed to agree on even a single problem. When problems were grouped into broad categories (e.g., delinquent, withdrawn), more than a third of the pairs still failed to agree on a single broad problem area. Parent-child agreement was higher for externalizing than for internalizing problem categories (though poor for both). Low parent-child agreement may help explain the poor outcomes often reported for clinic-based child therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
10.
To better understand what determines the support that family members perceive in dyadic family relationships, this study tested to what extent the perceiver, the partner, their specific relationship, and the family determine perceived support, and whether these effects differ for horizontal (i.e., marital and sibling) versus vertical (i.e., parent-child) relationships, or for different types of perceivers (i.e., parents versus adolescents). Two parents and two adolescents in 288 Dutch families judged the support perceived from each other. Social relations model analysis showed support perceptions to be more determined by the perceiver than by the partner, partly relationship specific, partly generation specific, and partly family specific. Relationship-specific support and reciprocity are more important in horizontal relationships than in vertical ones. Adolescents' support perceptions were more perceiver determined than were parents' perceptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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