镜对称及矢势的简单推导

对于某些电流分布与磁场分布,本文应用镜对称操作原理及Ｓｔｏｋｅｓ定理简单推导其矢势Ａ→。     

Effect of Distribution of Magnetic Flux Density on Purifying Liquid Metal by Travelling Magnetic Field

ＮｏｍｅｎｃｌａｔｕｒｅＦｅｌｅｃｔｒｏｍａｇｎｅｔｉｃｆｏｒｃｅ（ＥＭＦ）Ｂ（Ｂ０）ｍａｇｎｅｔｉｃｆｌｕｘｄｅｎｓｉｔｙ（ＭＦＤ）ＩｃｕｒｅｎｔｉｎｔｈｅｌｉｑｕｉｄｍｅｔａｌＥｖｏｌｔａｇｅｉｎｔｈｅｔｗｏｅｎｄｓｏｆｔｈｅＨａｌｄｅｖｉｃｅＲ...     

运动物体接收到的电偶极辐射电磁波

利用电极极辐射和狭义相对论的有关公式,导出了电磁波的多普勒效应公式及运动物体接收到的电磁波电磁能流密度随物体运动速度变化的规律。     

不同类型负荷对人体骨密度影响的研究

对举重、中长跑和不从事任何专项运动（对照组） 各３０ 名男青年的前臂骨进行了观察测定, 并对三组青年的前臂木尧、尺骨骨皮质、骨髓腔、骨矿含量和骨密度等进行了统计分析。结果表明： 木尧、尺骨骨皮质厚度是举重组大于中长跑组和对照组, 具有显著性差异, 且中长跑组略高于对照组, 但无显著性差异, 骨髓腔径未见随骨皮质增厚而缩小; 其木尧、尺骨骨矿物含量和骨密度在三组之间存在着显著性差异, 即举重组、中长跑组、对照组。     

关于有球练习密度对足球教学影响的研究

本文以体育系普修足球课的学生为研究对象,采用实验、统计和归纳分析等研究方法,通过课中增加有球练习密度为实验手段,结果发现,增加有球练习密度能明显提高学生学习成绩,其动力主要来源于学生的学习积极性和学生触球次数增加对技能形成的加速。     

Effects of biotic and abiotic factors on forest biomass fractions

The extent to which key factors at the global scale influence plant biomass allocation patterns remains unclear. Here, we provide a theory about how biotic and abiotic factors influence plant biomass allocation and evaluate its predictions using a large global database for forested communities. Our analyses confirm theoretical predictions that temperature, precipitation, and plant height and density jointly regulate the quotient of leaf biomass and total biomass, and that they have a much weaker effect on shoot (leaf plus stem) biomass fractions at a global scale. Moreover, biotic factors have larger effects than abiotic factors. Climatic variables act equally on shoot and root growth, and differences in plant body size and age, as well as community species composition, which vary with climate in ways that drown out the variations in biomass fractions. The theory and data presented here provide mechanistic explanations of why climate has little effect on biomass fractions.     

国际科学合作个体中心网的中印比较

采用美国<科学引文索引-扩展版>(SCI-E)1977-2006年收录的中国大陆的国际合著期刊论文114 717篇和印度的国际合著期刊论文52 790篇,统计了论文作者所属国家(地区)间的合作关系,得知中国有174个国际合著伙伴,印度有181个国际合著伙伴.比较了中、印两国国际科学合作的个体中心网结构,发现两国国际科学合作个体中心网具有基本相同的网络密度、中心势以及核心合作伙伴和明显不同的链密度,表明中国国际科学合作的集中性.在两国的核心合作伙伴中,亚洲伙伴在中国网中的重要性大于在印度网中的重要性,美洲伙伴在中国网中的重要性小于在印度网中的重要性.从地理区域来看,亚洲、欧洲、美洲对中国和印度国际科学合作的重要性基本相同,大洋洲在中国国际科学合作个体中心网的重要性大于在印度国际科学合作个体中心网的重要性,非洲在中国国际科学合作个体中心网的重要性小于在印度国际科学合作个体中心网的重要性.     

用双滤膜法测定氡析出率的实验研究

用双滤膜方法对居室和建材的氡析出率进行了可行性测定及探讨，数个测点实测结果表明：与常规的活性炭方法相比，双滤膜方法原理可行，操作简单，结果可比，是一种更加灵敏、高效、快速的氡析出率测定方法。     

The role of community in the development of elite handball and football players in Denmark

The primary purpose of this study was to investigate the effect of the place of early development in a sample of Danish male elite and youth handball and football players. The sample included 366 handball and football players from the elite Danish league in the season 2011–2012 and a comparison sample of youth players under the age of 12 from 2003, including 147,221 football and 26,290 handball players. Odds ratio analysis showed that both population size and density significantly affected the proportional number of youth players per community and the odds of athletes reaching an elite level in football and handball. The odds for youth player registrations in both handball and football increased in rural in contrast to urban communities. However, elite football players primarily came from communities of high density (>1000 pop./km²), whereas elite handball players primarily came from less densely populated communities (100 to <250 pop./km²). Furthermore, there seems to be a relation between representation of elite and talent clubs in different communities and the probability of becoming an elite player in both sports. The limited number of elite players in both sports from rural communities may be due to national talent development strategies that do not incorporate development support for clubs in rural areas. Additionally, the results of the study clearly suggest the need to include the youth player population to advance research findings in birthplace effect studies.     

Relationship of plasma homocysteine with lipid profile parameters in ischemic heart disease

The present study was undertaken to explore the relationship of plasma homocysteine with other biochemical parameters in ischemic heart disease. Plasma levels of total homocysteine was measured by HPLC—fluorescence detection with internal standard in 60 ischemic heart disease patients and were compared with 30 age matched normal healthy controls. The significant increase of plasma homocysteine was observed in both myocardial infarction and chronic stable ischemic heart disease patients when compared with the controls. The hyperhomocysteinemia appears be to due to increased body demand of vitamins such as folic acid, vitamin B₁₂, B₆, B₂ either alone or in combination to regulate normal homocysteine metabolism.