飞机升力的创新理论

发明发现无止境,研究开拓有创新。 飞机的机翼,是飞机升力的关键部分。机翼如鸟类的翅膀,能在天空中飞行。各种鸟类能在空气中作长距离的滑翔,能以很高的速度捕食昆虫。某些昆虫的翅膀很薄,即具有很好的空气动力稳定性。鸟类,昆虫的翅膀不仅要把自身的重量在空气中“托起”,     

AMINO ACIDS' PROTECTIVE EFFECTS ON EXPERIMENTAL ACUTE RENAL FAILURE

This study was carried out to elucidate the nephroprotective effects from a mixture of 8 L-amino acids and the possible mechanism of protection by this amino acid mixture. Acute renal failure model was induced by an intravenous administration of 10 mg/kg cisplatin to male Sprague-Dawley rats. A mixture of 8 L-amino acids or 0.9% saline was infused at a rate of 2 ml/h for 3 h, starting with a 2 ml bolus injection before cisplatin administration. Amino acids showed no acute effect on renal morphology. The infusion of a mixture of 8 L-amino acids increased GFR by 85% in control rats. The abnormalities of urine sodium and potassium excretion caused by cisplatin were markedly attenuated by the administration of the amino acid mixture. With the infusion of this amino acid mixture, cisplatin-induced abnormal state 4 respiration returned to control levels and the depressed state 3 respiration, respiratory control ratio and carbonyl cyanide p-trifluoromethoxyphenyl hydrazone-uncoupled respiration were ameliorated remarkably. A mixture of 8 L-amino acids showed marked nephroprotection against cisplatin-induced acute renal failure in rats and might function through augmentation of the cisplatin-injured renal mitochondrial electron transport-oxidative phosphorylation sequence, probably via stabilizing the membrane (including inner mitochondrial membrane) protein tertiary structure. In addition, this amino acid mixture remarkably increased GFR and decreased urine sodium excretion in rats.     

深圳股票市场的分形特征实证研究

本文应用R／S分析法实证研究了深圳股票市场的分形特征,并对其进行了整体分形结构的描述,揭示了深圳股票市场是分形市场．具有状态持续性、统计自相似和非周期循环的特征。此外,通过双对数图发现它存在一个300天的非周期循环。     

营销组合4P范式的不可替代性

营销组合范式从4P发展至4C、4R,引起学者的热烈反应和广泛讨论。在前人研究的基础上,将4P、4C、4R从产品、定价、渠道、促销四个方面进行对比,得出4P理论是具有实操性的营销组合工具,能为消费者提供实际的价值方案,更符合营销工具的实质,是营销学不可替代的理论根基。     

基于一般P-C矩阵的R族科学发展节律指标——科学发展节律指标研究(1)

一论文集的一般P-C矩阵由论文数据和引文数据两部分组成.基于一般P-C矩阵并引入"等时性"概念,我们创建了关键变量Ck.Ck表示的是不同年份发表的论文在各自发表后第k年的引文数量的平均值.借助Ck可以构建R族科学发展节律指标,定义为引文观察值和引文期望值的比值,用于反映科学发展的节律.R族指标包括4项指标①指标R--被引年视角加三角形引文窗口;②指标R′--被引年视角加平行四边形引文窗口;③指标r--引用年视角加三角形引文窗口;④指标r′--引用年视角加平行四边形引文窗口.以Journal of Documentation为例,本文具体说明了R族序列的计算和R族指标的应用.     

幕后之人 NBA的经纪人往事

除了合同金额之外,还要球队股份和私人飞机?这是科怀·伦纳德能做出的事情吗?我们无法相信,一贯沉默寡言的伦纳德会提出这样的要求。但根据美国媒体的爆料,他的团队在去年夏天确实向一些意向球队提出了过分的要求,例如股份、私人飞机、住宅和有保障的赞助合同等等,这严重违反了NBA的谈判协议。虽然伦纳德本人表示自己并不知情,而且也缺乏证据,但关于NBA球队非法招募球员的现象依然成为了当下最热的话题。