ZigBee技术在门禁系统的应用

现行市场的门禁系统中,现场总线一统天下,但随着社会的发展,它的缺陷越来越明显。本文提出了ZigBee技术在门禁系统的一个应用实例,主要讲述了ZigBee的基本概念、整个应用的网络结构、门禁控制器的硬件实现、数据传输机制和安全性等方面的内容。     

Sliding mode control for active magnetic bearing system with flexible rotor

This paper presents the analysis and control of active magnetic bearing (AMB) systems with a flexible rotor. A sliding mode controller design scheme is proposed to compensate for the nonlinear effects of the AMB system. A nonlinear model of the AMB system with an electromagnetic actuator and a flexible rotor is proposed to facilitate the present system analysis and controller design. This nonlinear model takes into account the dynamics of the flexible rotor, the characteristics of the nonlinear electromagnetic suspended system, and the contact force between the auxiliary bearing and the shaft. This study also considers the auto-centering control of the AMB system when subjected to disturbances and variations in the system parameters. The numerical results show that the system exhibits a periodic motion and demonstrates high accuracy and robustness when operating under sliding mode control.     

关于加强高校教学团队建设的思考

高水平教学团队建设是提高高等教育质量的迫切需要。与科研团队和企业团队相比,教学团队具有目标明确但显示度较低、个体独立性强但参与度较低、凝聚手段非物质性、组织扁平化等特点。本文结合学校实践,提出高校教学团队建设应注重信念培育、优势集成、利益兼顾,与科研团队建设相结合等,从而使高校教学团队成为教学改革的先行者和教师的成长基地。     

How home gets to school: Parental control strategies predict children's school readiness

At-risk families’ control style (autonomy support and coercive control) was examined in relation to children's school readiness; children's social skills and mastery motivation were hypothesized mediating variables. In two different, low-income samples from diverse ethnic backgrounds, one preschool sample recruited from Head Start (N = 199) and a school transition sample composed of children entering elementary school (N = 344), parental control styles were related to children's academic readiness modestly but significantly in the preschool sample and weakly in the school transition sample. Children's social skills and mastery motivation skills (persistence and goal orientation) were significantly related to the academic measures of school readiness, and fully mediated the association between parents’ use of coercive behavioral control and academic readiness. Such mediation could not be tested for parental support of children's autonomy. The results indicate that a developmental cascade exists between parental control strategies and academic indices of school readiness, emphasizing the importance of family context models of school readiness. Furthermore, strong correlations between the domains of school readiness were found in both samples, reinforcing calls for a multidimensional approach to supporting school readiness in early childhood education programs.     

Feminising and masculinising primary teaching: a critical examination of the interpretive frameworks of male primary school principals in Hong Kong

Over the past two decades, the feminisation of primary school teaching has been identified by the media and government officials in Western countries as an important contributing factor to boys' academic problems. This panic, which has been criticised by feminists as a backlash and a form of recuperative politics, has promoted the development of research into gender and education, particularly studies related to the gendered culture of primary schools and on the masculinities of male teachers. However, male primary principals remain relatively under-researched in the literature, despite the importance of their structural position and increasing concern over the masculinisation of school leadership. This paper aims to contribute to the discussion by critically analysing the interpretive frameworks of 12 male primary school principals. The findings reveal not only the complex, contradictory and at times culturally specific gendered discourses that some male principals employ, but also their feminising and masculinising effects on the school workplace and leadership.     

Motivation and students’ use of learning strategies: Evidence of unidirectional effects in mathematics classrooms

Considerable evidence indicates that student motivation and use of learning strategies are related. There is insufficient understanding, however, about their reciprocal effects—whether motivation affects strategy use, the converse, or whether the effects are bidirectional—and which components of motivation and strategies are involved. A two-wave longitudinal design was used to examine this issue among 9th grade students (N = 306) enrolled in high school mathematics classes during an academic term. A cross-lagged structural model found that students’ self-efficacy in mathematics and value predicted their reported use of learning strategies. There was no evidence, however, that learning strategy use predicted motivation and, thus, support for unidirectional effect of motivation during that time interval. Implications for models of self-regulated learning and instruction are discussed.     

Academic delay of gratification and children's study time allocation as a function of proximity to consequential academic goals

Students (N = 302) in Chinese elementary schools were assessed regarding their academic delay of gratification (ADOG) and reported the time they devoted to non-school study and playtime during an extended interval prior to taking a high-stakes final exam. Students high compared those low in ADOG were more likely to spend time studying and less time playing several weeks prior to the exam. Growth curve analyses verified, however, that this difference diminished as a function of the temporal proximity to the exam, and that the group differences were non-existent just before the exam. Associations between ADOG and students' academic motivation and use of learning strategies replicated those obtained previously with adults in the USA. Results contribute to the general literatures on volition, homework and the dynamics of conflicting goals and action tendencies.     

课堂合作研讨的有效策略探讨

在课堂上开展有效的合作研讨,需要注意运用各种策略。角色策略:教师转变角色,让学生成为课堂研讨学习的主体。目标策略:教师有明确的目标意识和目标管理能力。激发、诱导策略:教师善于激发、诱导学生进入合作研讨的学习场。调控策略:注意对全体学生进行全局性调控,注意调控目标方向、节奏和进度、课堂氛围等。创新策略:努力创新研讨内容和研讨形式。评价策略:发挥教学评价的功能,注意评价的及时性、正反评价的结合、评价的多元化等。     

中国参与周边区域经济合作的实践与策略

党的十七大报告明确提出我国要"实施自由贸易区战略"。研究认为:首先发展与周边国家和地区的区域经济合作,并以此为基础,逐渐建立中国的区域经济合作网,是中国自由贸易区战略的核心。文中首先分析中国参与周边区域经济合作的进程与特点,然后以《内地与香港建立更紧密经贸关系安排》(CEPA)和《中国—东盟自由贸易区》(CAFTA)为例,深入探讨了中国参与周边区域经济合作的实践效应及现存问题,最后通过GTAP模型测算,提出中国自由贸易区战略核心——周边整合的具体策略。     

Parents' involvement in adolescents' schooling: a multidimensional conceptualisation and mediational model

This study examined the impact of parental involvement on adolescents' academic achievement in Korean families. The major strengths of the current research are the study of multiple dimensions of parental involvement, the longitudinal design and the consideration of mediating variables. Structural equation modelling was used to examine the direct and indirect effects of parental involvement on students' academic achievement using data from a nationally representative sample of middle school students from the Korea Youth Panel Survey. Results indicated: (1) parental involvement dimensions positively influenced achievement through its effects on student self‐concept and locus of control; and (2) parents' increased participation in involvement practices (monitoring, educational expectation and affection) increases students' self‐concept and locus of control.