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1. 儿童青少年运动员应该食用多样化的食物,其中,蛋白质应占膳食总能量的12%-15%,碳水化合物至少占55%,而脂肪至多占30%。日常生活中如何吃才能满足这些要求呢?膳食指南宝塔提供了一条可行之道。2.有些营养素对热爱运动的儿童青少年运动员非常重要,要保证摄入充足,这些营养素是碳水化合物(包括纤维素)、维生素B6、维生素D、铁、钙、镁、锌、铬。科学合理、包罗各类食物的平衡膳食,对青少年运动员最大程度地全面摄取各种营养素,满足生长发育和运动训练的需要,是非常必要的。3.鼓励儿童青少年运动员在运动训练前、中、后进行补液,以避免脱水的发生。4.如果膳食合理平衡,就没必要额外补充营养品。  相似文献   
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OBJECTIVES: Medical Library Association (MLA) members were surveyed to gather background about the current state of expert searching in institutions. The survey results were intended to guide the recommendations of the Task Force on Expert Searching for promoting the importance of expert searching and implementing those recommendations. METHODS: MLA members were surveyed, and data obtained from the survey were compiled and analyzed to answer three general questions: what is the perceived value of searching skills to the institution, how do health sciences librarians maintain and improve their searching skills, and how are searching services promoted and/or mandated in the institution. RESULTS: There were 256 responses to the survey. Over 95% of the respondents saw their expert-searching skills were of value to their institutions, primarily through performing mediated searches and search consultations. Over 83% of the respondents believed that their searching skills had improved over the past 10 years. Most indicated that continued training was very important in maintaining and improving their skills. Respondents promoted searching services most frequently through orientations, brochures, and the libraries' Web pages. No respondent's institution mandated expert searching. Less than 2% of respondents' institutions had best practice guidelines related to expert searching, and only about 8% had guidelines or policies that identified situations where expert searching was recommended. CONCLUSIONS: The survey supports the belief that health sciences librarians still play a valuable role in searching, particularly in answering questions about treatment options and in providing education. It also highlights the need for more expert searching courses. There has been minimal discussion about the perceived need for expert-searching guidelines in the institutions represented by survey respondents.  相似文献   
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Black-dyed artefacts are found in museums worldwide, many produced using an iron-tannate compound. Deterioration of iron-tannate dyed artefacts is an international preservation issue: in New Zealand the deterioration of paru (iron-tannate) dyed Māori textiles is widespread. This article reports experimental work testing the efficacy of sodium alginate, a consolidant developed for deteriorated paru-dyed muka (fibre from harakeke; Phormium tenax). The colour stability, strength retention, and acidity of paru-dyed muka consolidated with sodium alginate (0.25, 0.5, and 1% w/v in water) was tested pre- and post-artificial light ageing. This study found that sodium alginate had no negative effect on paru-dyed muka and in some cases provided benefit. Interestingly, the colour of paru-dyed muka is substantially more stable in UV-filtered light than previously recognised. Also microfading results were in agreement with visual assessments of colour change at 1 Mlux hour exposure, providing confidence in this relatively new technique to assess colour change.  相似文献   
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The independence of the media under Ghana’s Fourth Republic is assessed from the perspective of standards and professionalism. Using a qualitative method, the study shows that unethical practices are evident in the print media landscape in Ghana, and argues that this can be traced to four major spheres: educational qualification, existence of several professional associations, a weak regulatory body and “money matters”. Overall, the study argues that legalities form a minimal part of the independence of the Ghanaian media but concerns about freedom seem to be self-inflicted by the very media practitioners through their actions and sometimes questionable reportage.  相似文献   
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Abstract

This paper summarises the results of an investigation of Solomon Islands secondary school students’ interpretations of three concepts: vision, animals and burning. Internal comparisons among the three areas and external comparisons with findings reported from other societies are made. While some support is given to the idea that children from different cultures may develop similar conceptions, this support is qualified and is shown to be dependent on the type of phenomenon investigated. The degree to which there is immediate personal experience of phenomena may be important, as may the presence or absence of culturally supported explanations. The commonly reported resistance of children's conceptions to school science teaching is also shown not to be universally true. The article ends with a plea for caution in the cross‐cultural extrapolation of research into children's conceptions.  相似文献   
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