几种补充学龄前儿童维生素C的水果的光谱分析     

回瑞华  刁全平  侯冬岩  李铁纯 《鞍山师范学院学报》2013,(4):24-27

为了补充学龄前儿童维生素C的需要,采用光谱法对几种水果中维生素C的含量进行分析.通过单因素实验和正交实验确定了最佳条件.光谱法的标准曲线为Y=0.019 5X+0.076 8,相关系数r=0.999 5,变异系数为0.12,回收率为99.17%~100.3%.  相似文献   

C语言课程项目教学研究与实践     

周丰  戴伯勇 《天津电大学报》2013,(2):45-48

在C语言课程教学中实施项目教学能实现学生学习方式的转变,实现学生自主学习的教学目标。在实施项目教学前,可采用案例教学等方法使学生储备充足的知识。当学生具有一定的独立探究能力后,即可开展项目教学。在教师的指导下,学生组建学习小组,共同选定合适的研究性学习项目,并列出研究计划,进行分工合作。教师要引导学生高效地获取资料,引导学生交流、讨论、提高。学生经过"发现问题、研究探讨、解决问题"的学习过程,重构自己的知识、能力结构,培养创新意识,达到较好的学习效果。  相似文献   

基于GRI模型和C5．0规则集的图书推荐模式研究     

苏静  赵捷 《数字图书馆论坛》2012,(10):52-56

通过应Clementine12．0中关联规则的GRI模型和C5．0推理规则集,对问卷涉及的205位青少年用户基本信息和图书购买信息进行数据建模和分析。研究结果表明,单个用户购买的多类图书之间,具有相同购买特征（如性别、年龄、教育背景等）的用户群和某类图书之间均存在一定的关联规律。在此基础上,提出了基于GRI模型和C5．0规则集的图书推荐模式,即跨类型和相同用户兴趣的图书推荐,试图为图书馆和图书零售市场开展图书推荐服务提供参考。  相似文献   

Toward a Longitudinal Model of e-Commerce: Environmental,Technological, and Organizational Drivers of B2C Adoption     

Inma Rodríguez-Ardura  Antoni Meseguer-Artola 《The Information Society》2013,29(3):209-227

Despite the important benefits for firms of commercial initiatives on the Internet, e-commerce is still an emerging distribution channel, even in developed countries. Thus, more needs to be known about the mechanisms affecting its development. A large number of works have studied firms' e-commerce adoption from technological, intraorganizational, institutional, or other specific perspectives, but there is a need for adequately tested integrative frameworks. Hence, this work proposes and tests a model of firms' business-to-consumer (called B2C) e-commerce adoption that is founded on a holistic vision of the phenomenon. With this integrative approach, the authors analyze the joint influence of environmental, technological, and organizational factors; moreover, they evaluate this effect over time. Using various representative Spanish data sets covering the period 1996–2005, the findings demonstrate the suitability of the holistic framework. Likewise, some lessons are learned from the analysis of the key building blocks. In particular, the current study provides evidence for the debate about the effect of competitive pressure, since the findings show that competitive pressure disincentivizes e-commerce adoption in the long term. The results also show that the development or enrichment of the consumers' consumption patterns, the technological readiness of the market forces, the firm's global scope, and its competences in innovation continuously favor e-commerce adoption.  相似文献   

Vitamin C in Disease Prevention and Cure: An Overview   总被引：1，自引：0，他引：1  

Shailja Chambial  Shailendra Dwivedi  Kamla Kant Shukla  Placheril J. John  Praveen Sharma 《Indian journal of clinical biochemistry : IJCB》2013,28(4):314-328

The recognition of vitamin C is associated with a history of an unrelenting search for the cause of the ancient haemorrhagic disease scurvy. Isolated in 1928, vitamin C is essential for the development and maintenance of connective tissues. It plays an important role in bone formation, wound healing and the maintenance of healthy gums. Vitamin C plays an important role in a number of metabolic functions including the activation of the B vitamin, folic acid, the conversion of cholesterol to bile acids and the conversion of the amino acid, tryptophan, to the neurotransmitter, serotonin. It is an antioxidant that protects body from free radical damage. It is used as therapeutic agent in many diseases and disorders. Vitamin C protects the immune system, reduces the severity of allergic reactions and helps to fight off infections. However the significance and beneficial effect of vitamin C in respect to human disease such as cancer, atherosclerosis, diabetes, neurodegenerative disease and metal toxicity however remains equivocal. Thus further continuous uninterrupted efforts may open new vistas to understand its significance in disease management.  相似文献   

广东省体育学研究生教育竞争力研究     

隗金水  朱征宇 《广州体育学院学报》2013,33(1):7-11

主要以文献资料法、比较分析法从整体实力、学科门类、一级学科、二级学科专业、博士生培养等方面对广东省近四年体育学研究生教育竞争力进行了系统的研究,以图在了解我省体育学研究生教育现状的同时,为我省未来的体育学研究生教育发展决策提供理论依据和定量数据。  相似文献   

Not just Any Wintry Afternoon in England: the curious contribution of C.R.W. Nevinson to ‘football art’     

John Hughson 《国际体育史杂志》2013,30(18):2670-2687

This paper considers the painting Any Wintry Afternoon in England (1930) (AWA) by the prominent artist and social commentator C.R.W. Nevinson (1889–1946). The painting is one of few, and perhaps the best-known, by an English fine artist to take football as its subject matter during the first 40 years of that sport's professional existence. The paper concentrates on gaining an understanding of this painting within the context of Nevinson's biography. Of course, a painting may well be admired by viewers without any knowledge of the painter at all, and no issue is taken in the paper with the possibility of totally independent readings. But from an art-history and cultural-history perspective, knowledge of a painter's biography is significant in allowing for consideration of the artwork as a product of its time. In the case of AWA, knowledge of Nevinson's hostility to sport supports the view of a leading critic, on the occasion its of its exhibition, that the painting was intended as a satire on the mass popularity of football in England in the 1920s. Forearmed with this knowledge, wariness can be taken against subsequent attempts to locate AWA within a genre of ‘football paintings’ that represent an enthusiasm for the game. Nevinson's earlier involvement with Futurism had acquainted him with that movement's tendency to take aspects of popular culture as inspiration for art. But Nevinson took football as a derisory subject matter rather than inspiration and in doing so put AWA at odds with the contemporaneous visual representations of football that had begun to appear in popular mediums such as postcards and film. Yet, contrary to some wishful interpretations though it may be, AWA, owing to its very contrariness, remains an important historical image in the visual representation of football as popular culture.  相似文献   

Methods matter: Improving causal inference in educational and social science research: A review article     

Eric R. Eide  Mark H. Showalter 《Economics of Education Review》2012

Professors Richard J. Murnane and John B. Willett set out to capitalize on recent developments in education data and methodology by attempting to answer the following questions: How can new methods and data be applied most effectively in educational and social science research? What kinds of research designs are most appropriate? What kinds of data are needed? What statistical methods are best used to process these data, and how can results be interpreted so that policymakers are best informed? In this review we summarize main contributions of the book, assess the unique value-added of the text, and discuss the usability of it to various potential audiences.  相似文献   

On the allocation of resources for secondary schools     

Carla Haelermans  Kristof De Witte  Jos L.T. Blank 《Economics of Education Review》2012

This paper studies the optimal allocation of resources – in terms of school management, teachers, supporting employees and materials – in secondary schools. We use a flexible budget constrained output distance function model to estimate both technical and allocative efficiency scores for 448 Dutch secondary schools between 2002 and 2007. The results indicate that the average technical efficiency amounts to about 78 percent, implying that, with the given resources, schools could improve students’ educational performance by 28 percent. In terms of allocative efficiency, we estimate a 0.65 percent overutilization of teachers while management and supporting personnel are underutilized. The outcomes indicate that, despite the significant variation among schools, the average school is close to the optimal allocation of teachers.  相似文献   

Embedded C programming: a practical course introducing programmable microprocessors     

David M. Laverty  Jonny Milliken  Matthew Milford  Michael Cregan 《European Journal of Engineering Education》2012,37(6):557-574

This paper presents a new laboratory-based module for embedded systems teaching, which addresses the current lack of consideration for the link between hardware development, software implementation, course content and student evaluation in a laboratory environment. The course introduces second year undergraduate students to the interface between hardware and software and the programming of embedded devices; in this case, the PIC (originally peripheral interface controller, later rebranded programmable intelligent computer) microcontroller. A hardware development board designed for use in the laboratories of this module is presented. Through hands on laboratory experience, students are encouraged to engage with practical problem-solving exercises and develop programming skills across a broad range of scenarios.  相似文献