平直界面一维晶体生长问题的相似解

对于平直界面下由过冷边界开始的熔体的一维凝固过程，考虑液态中远场温度高于凝固温度，而底板温度低于凝固温度，利用相似性解法分别求解固液态温度，分析其结果，说明由低温区长入高温区的界面总是稳定的，从而更加完善了一维晶体生长理论．     

经济全球化对高校学生思想教育的影响及对策

经济全球化对高校学生思想教育有积极影响,也有消极影响。研究这种影响的新特征,探索新的应对策略,具有重要的理论价值和实践价值。     

A new pedagogical model for adventure in the curriculum: part one – advocating for the model

Background: In recent years increasing attention has been given to models-based approaches to physical education as a way of promoting standards and particular types of learning through better alignment of teacher planning and delivery with pupil learning and achievement. However, little attention has been given to the specific contribution a pedagogical model for outdoor adventure education (OAE) has to make to pupils learning.

Purpose: This paper is presented in two parts. Part one is an advocacy paper and draws upon the broader discourse around models-based practice to make a case for the development of a pedagogical model for OAE. Drawing upon guidelines for models-based approaches to physical education, this paper considers the theoretical foundation, rationale, review of research findings and major theme that inform the development of a model of OAE.

Conclusions: The selected review of the research suggests that the major impact of OAE is upon the affective domain, particularly in relation to pupils developing a positive self-concept. Learning is also evident in the cognitive and physical domains, but this is secondary to learning in the affective domain. Drawing upon the analysis of the research literature, the major theme for the model is identified as ‘personal growth through adventure’ and ‘OAE’ is suggested as the name of the model. Part two of this paper builds upon these foundations to outline what a pedagogical model for OAE might look like in a secondary school in the UK.     

The effect of 14 weeks of vitamin D3 supplementation on antimicrobial peptides and proteins in athletes

Heavy training is associated with increased respiratory infection risk and antimicrobial proteins are important in defence against oral and respiratory tract infections. We examined the effect of 14 weeks of vitamin D₃ supplementation (5000 IU/day) on the resting plasma cathelicidin concentration and the salivary secretion rates of secretory immunoglobulin A (SIgA), cathelicidin, lactoferrin and lysozyme in athletes during a winter training period. Blood and saliva were obtained at the start of the study from 39 healthy men who were randomly allocated to vitamin D₃ supplement or placebo. Blood samples were also collected at the end of the study; saliva samples were collected after 7 and 14 weeks. Plasma total 25(OH)D concentration increased by 130% in the vitamin D₃ group and decreased by 43% in the placebo group (both P = 0.001). The percentage change of plasma cathelicidin concentration in the vitamin D₃ group was higher than in the placebo group (P = 0.025). Only in the vitamin D₃ group, the saliva SIgA and cathelicidin secretion rates increased over time (both P = 0.03). A daily 5000 IU vitamin D₃ supplement has a beneficial effect in up-regulating the expression of SIgA and cathelicidin in athletes during a winter training period, which could improve resistance to respiratory infections.     

Neuromuscular and technical abilities related to age in water-polo players

Testing is one of the important tasks in any multi-step sport programme. In most ball games, coaches assess motor, physical and technical skills on a regular basis in early stages of talent identification in order to further athletes’ development. The purpose of the study was to investigate anthropometric variables and vertical jump heights as a free throw effectiveness predictor in water-polo players of different age groups. Two hundred and thirty-six young (10–18 years) male water-polo players partitioned into three age groups underwent anthropometric variables’ measures and squat- and countermovement-jump tests, and performed water-polo free throws. Anthropometric variables, vertical jump heights and throw speed – as a proxy for free throw effectiveness – resulted different over age groups. Particularly, throw speed changed from 9.28 to 13.70 m · s^?1 (+48%) from younger to older players. A multiple-regression model indicated that body height, squat-jump height and throw time together explain 52% of variance of throw speed. In conclusion, tall height, high lower limb power and throwing quickness appeared to be relevant determinants for effective free throws. Such indications can help coaches during talent identification and development processes, even by means of novel training strategies. Further research is needed over different maturity statuses.     

黑龙江省冰雪装备制造业创新成长影响要素与战略研究

随着我国成功申办2022年冬奥会,我国将大力发展冰雪运动,并会随之带动旅游、经济和冰雪装备制造业的发展。而冰雪装备制造业的发展直接影响我国冰雪体育事业的开展。采用文献资料、调查、系统分析等研究方法,针对黑龙江省冰雪装备制造业的创新成长问题进行研究,并对黑龙江省的冰雪装备制造业创新成长影响要素以及企业创新成长存在的问题进行分析与总结,认为黑龙江省冰雪装备制造业创新成长的总体状况是良好的,但企业存在资金短缺,经营、管理、技术等方面人才匮乏,企业产品结构单一、产品科技创新意识和能力不强,欠缺可持续发展理念等问题。通过分析影响冰雪装备制造业创新成长的原因,提出引进与自我创新相结合、注重品牌质量、发扬政府主导优势等战略,旨为冰雪装备制造业在黑龙江省的发展提供理论依据。     

冬泳运动对中老年人身体成分的影响分析

对齐齐哈尔市冬泳协会的116名冬泳爱好者进行身体成分测试。结果显示：长期进行冬泳运动,可以改善中老年人的身体成分,降低体脂百分比和肥胖发生率,提高身体素质,对预防心血管疾病及老年性骨质疏松具有积极意义。     

广义马氏过程及其熵率

讨论了k步广义马氏过程及其时间不变性和平稳性，给出了熵率的两种定义，说明了其等价性，还给出了平稳的广义马氏链熵率的计算公式．     

食物浓度及低浓度镉对水螅种群动态的影响

在温度为20士1℃、自然光照(光照强度约为301x,L : D=14 : 10)条件下,分别以浓度为0.25ind/ml、0.5ind/ml、1.0ind/ml、2.0ind/ml枝角类(Cladocemans)为食物及在1.0ind/ml食物浓度下,应用单个体培养法及群体累积培养法研究了食物浓度及低浓度镉离子(0mg/l(对照组)、0.01mg/l、0.05mg/1)对水螅种群动态的影响.实验表明,食物浓度对水螅种群增长有一定影响,在较高食物浓度下水螅的种群增长率、净增长率普遍提高,而镉子浓度对水螅种群增长有显著影响.在较高离子浓度下,水螅种群增长率、净增长率较大,而世代时间相对缩短.     

始终代表先进生产力的发展要求是全面建设小康社会的关键

随着对小康社会认识的不断深入,以经济建设为中心,不断解放和发展生产力,成为全面建设小康社会的战略选择,也是“三个代表”思想的重要体现。