Learning science through research apprenticeships: A critical review of the literature

Science education models for secondary and college students as well as K‐12 teachers have been dominated by classroom‐based approaches. Recently, research apprenticeships wherein learners worked with practicing scientists on authentic scientific research have become increasingly popular. The purpose of this critical review of the literature was to review and synthesize empirical studies that have explored learning outcomes associated with research apprenticeships for science learners. We reviewed 53 studies of scientific research apprenticeship experiences for secondary students, undergraduates and teachers, both pre‐service and in‐service. The review explored various learning outcomes associated with participation in research apprenticeships. These outcomes included effects of apprenticeship experiences on participant career aspirations, ideas about the nature of science (NOS), understandings of scientific content, confidence for doing science and intellectual development. The extant literature supported many of the presumed positive associations between apprenticeship experiences and desired learning outcomes, but findings related to some themes (e.g., NOS understandings) supported conflicting conclusions. Implications included importance of the length of the apprenticeship, need to explicitly place attention on desired outcomes, and engagement of participants. © 2009 Wiley Periodicals, Inc. J Res Sci Teach 47:235–256, 2010     

Thinking in a ‘worldly’ way: mobility,knowledge, power and geography

In order to enhance understandings of the international mobility of researchers and the implications of their mobility for knowledge production and circulation, we need to develop more sophisticated conceptual resources. Here we draw on and seek to develop ideas generated from literary theory and geography in order to highlight the links between internationally mobile researchers, knowledge, geography and power. In particular, we develop three interrelated concepts: ‘geographies of power/knowledge’, ‘empires of knowledge’, and ‘edges of empires’. We also turn to Edward Said's notion of the ‘exilic intellectual’ because it speaks to the manner in which some mobile individuals navigate this terrain, as well as to issues of their links to place, positionality and the academy. The paper puts these concepts to work as we ask ‘What do they look like through the lens of an individual's intellectual biography?’ and ‘How can a biography add nuance to the concepts?’ Overall we adopt what Said calls a ‘worldly’ perspective that involves considering the time and place of ideas.     

Educational consequences of orphanhood and poverty in western Kenya

During the past decades, many developing countries have been severely hit by a combination of poverty and the HIV pandemic. However, there has been a debate about the relative contribution of these two factors. This study showed that poverty and orphanhood were two separate but interrelated factors contributing to poor schooling. There were no differentials shown based on double orphanhood or gender. We recommend that educational policies should put into consideration both poverty and orphanhood in order to increase schooling access for children affected by HIV/AIDS and poverty.     

The socioeconomic impact of HIV/AIDS on education outcomes in Uganda: School enrolment and the schooling gap in 2002/2003

Due to high prime-age mortality—a result of the HIV/AIDS scourge, the number of orphans in Uganda continues to rise. Using the 2002/2003 Uganda National Household Survey, this paper investigates how HIV/AIDS orphan status affects schooling enrolment and grade progression. Our results show that HIV/AIDS orphans are not significantly less likely to continue schooling but are by far more likely to fall below their appropriate grade. Furthermore, we find that the schooling gaps decreases at higher levels of household welfare status—poor HIV/AIDS orphans, especially aged 13–17 years, are significantly less likely to continue schooling.     

一种新型的复合式开关稳压电源的设计

本文给出一种实用的输出精密的复合式开关稳压电源设计方法.给出具体的设计电路和实际中应注意的一些事项.该电源具有重量轻、体积小、效率高等优点,是一种较为理想实用的精密稳压电源.     

耗散颗粒动力学模拟油水体系相行为

用耗散颗粒动力学模拟方法（Dissipative Particle Dynamics,DPD）研究了油分子量、油分子浓度、剪切及表面活性剂SDS（十二烷基硫酸钠）对油水体系相行为的影响.发现随着油分子量的增加,油水界面张力增加;随着油浓度的增加,体系由最初的水包油聚集状态逐渐演变为油水分层状态.随着剪切速率的加大,油滴被逐渐拉长,最后断裂;表面活性剂加入油水体系后,以亲水头基伸入水相、疏水尾巴伸入油相的方式分布在油水界面上.     

中药寒热相关药性和抑制脂肪酸合酶能力关系的探索

测定了药典中106味温热性中药和119味寒凉性中药对脂肪酸合酶的抑制水平,发现温热药中对该酶强抑制的频数高于寒凉药约38%. 进一步分析发现,温热药中的温里和散内寒药中强抑制药的频数大幅提高,而寒凉药中的清热泻火、明目、清虚热药中强抑制药的频数则进一步降低,差异均具有显著性. 综合以上结果提出,直接影响能量代谢系统、造成能量代谢率变化是形成中药的寒热药性的因素之一.     

WRF土地利用/覆被数据优选及其在城市热岛模拟中的应用

针对WRF模式自带土地利用数据更新不及时及精度不高的现象,本文将国内外主要土地利用数据（MODIS2012、GLC2009、GLC2000）与WRF模式耦合进行土地利用数据的优选,并将优选数据初步应用于枣庄城市热岛模拟中。结果表明：①MODIS2012数据能够较好地反映研究区域土地利用类型的空间分布特征,有较好的模拟结果;②研究区10月份热岛强度最大为0.671℃,其次是1月份和7月份分别为0.570℃和0.550℃,而4月份热岛强度较小为0.467℃;城市热岛强度日最大值出现在22~23点,最小值出现在13~14点;③由于盛行风向的影响,滕州市与枣庄市中区城市热岛中心均存在春夏季北进、秋冬季南移的现象;④枣庄地区城市热岛主要受枣庄市中区的影响,各土地利用类型对城市热岛的贡献率大小排序为：城镇建设用地>农田>林地>未利用地>草地>水体。     

生态建设工程对鄱阳湖区域土地利用/覆被变化的影响

生态建设工程可在很大程度上快速改变区域土地利用/覆被格局。本文以鄱阳湖区域三个典型村落为研究对象,利用遥感手段和实地调研获取研究区生态建设工程实施前(2000年)、后(2013年)土地利用信息,在此基础上,结合农户问卷调查,从土地利用程度综合指数(L_j)、土地利用重要性指数(C_i)、林草植被覆盖度(I)指数等方面,分析土地利用变化特征。结果表明:总体上,生态工程建设实施后,鄱阳湖典型村落土地利用程度均呈下降趋势,林草植被覆盖度呈上升趋势。这对于改善鄱阳湖区域生态环境质量具有重要的意义。不同生态建设工程对鄱阳湖区域典型村落土地利用变化影响差异明显。其中,退田还湖工程引起的土地利用变化的重要性指数相对较高,对综合土地利用程度和林草植被覆盖度影响最大;“一大四小”工程引起的土地利用变化的重要性指数也相对较高。单一的“一大四小”工程对土地利用程度和林草植被覆被度的影响较小,但“一大四小”工程与退田还湖工程重合部分使土地利用程度下降,林草植被覆盖度提升。退耕还林工程引起的土地利用变化的重要性指数相对较低,其对土地利用程度和林草植被覆盖度影响较大。     

名人代言目的地对旅游者态度和行为的影响

聘请名人担任形象代言人逐渐成为一种流行的目的地营销策略,但旅游学界对名人代言的研究才刚刚起步。采用准实验设计研究方法,以大学生为样本收集数据,使用结构方程模型检验了名人代言的主流范式“一致性假说”在旅游研究领域的适用性。研究发现：①名人/目的地一致性通过名人可信度影响旅游者的目的地态度和旅游意向,即旅游者感知到名人形象与目的地形象越一致,他们对该名人担任代言人的信任度就越高,进而就会对其代言的目的地形成好感并产生较强的旅游意向;②名人/自我一致性通过名人认同影响旅游者的目的地态度和旅游意向,即旅游者感知到名人形象与自我形象越相似,他们对该名人的认同度就越高,因而对其代言的目的地就会产生较好的态度和较强的旅游意向。