对2002年世界杯场地自行车赛女子3km个人追逐赛的分析   总被引：1，自引：0，他引：1  

赵志英  李红 《首都体育学院学报》2002,14(4):24-27

收集了2002年世界杯第五站女子3km个人追逐赛的全部数据，对参赛的世界各国运动员在比赛中的表现作了统计学的分析，并由此对我国女子3km个人追逐赛的训练与发展提出了新的看法。  相似文献   

改进血型实验方法,培养学生综合能力     

彭晓云  王焰山 《实验室研究与探索》2006,25(8):896-898

改进血型定性实验为综合性实验,试制血型诊断抗体和诊断红细胞悬液,满足中学生血型实验试剂需求。自正常A、B型血样分离血清或红细胞,玻片法定性倍比稀释定量检测抗A、抗B,滤菌后冷藏;生理盐水洗涤红细胞,离心沉淀,冷藏。用自制诊断抗体和诊断红细胞悬液与标准试剂对比检测样本60例。自制诊断抗体与诊断红细胞悬液的诊断结果与标准试剂无显著性差异。大学生自制诊断抗体与诊断红细胞悬液基本达到生物制品诊断试剂的标准,大大降低学校用血型试剂成本,也有利于培养大学生综合技能。  相似文献   

除虫菊细胞悬浮培养3种方法的比较     

李小六  田立民  陈超  杨松元 《衡水学院学报》2005,7(1):18-20

利用克氏瓶法、琼脂增稠法、纱布球法3种方法研究除虫菊细胞生长速率的变化。比较3种方法得出克氏瓶法悬浮培养细胞的生长速率最快,达0. 083g干重/(L·d),第12d为最佳收获时期,最大收获量为0. 996g干重/L。  相似文献   

液固两相槽道流中柱状粒子取向的数值研究   总被引：1，自引：0，他引：1  

周强  林建忠  王叶龙 《科技通报》2004,20(5):375-380

对柱状粒子在槽道流场内的运动进行数值模拟，然后用统计方法得出大量柱状粒子的取向分布；给出了粒子长径比、粒子密度和流场区域对粒子取向分布的影响．计算结果表明，柱状粒子长径比的变化对粒子取向分布的影响不明显，粒子密度对粒子取向分布有一定影响，而流场区域所造成的流场横向速度梯度对粒子取向分布有重要影响．随着流场横向速度梯度增大，粒子取向趋势愈加明显，且当流场横向速度梯度增大到一定程度时，粒子取向都趋向于流动方向．文中部分结果与相关实验进行了比较，两者定性吻合较好。  相似文献   

热解法合成P（AM-co-MAA）/SnO_2有机-无机复合微球的研究     

杨菊香  龙旭  杨晓慧 《西安文理学院学报》2011,(4):33-37

采用反相悬浮聚合法合成了聚丙烯酰胺-甲基丙烯酸（P（AM-co-MAA））微凝胶,并以其作为模板,通过热解法制备了一系列微米级、表面具有特异结构的P（AM-co-MAA）/SnO2有机-无机复合微球材料.详细考察了反应时间、SnCl4的浓度和热解温度等因素对复合微球的形貌结构的影响.通过SEM,XRD,FT-IR,TG等手段来表征复合微球的结构、形貌、含量.微球上沉积的SnO2层随着SnCl4的浓度增大而加厚.采用模板法制备复合材料具有操作过程简单、反应条件温和等特点,因此,可将此方法可进一步拓展到其他有机-无机复合材料的制备中.  相似文献   

追诉时效与刑事诉讼程序之关系的反思——浅析创设追诉时效中止制度的必要性     

苏承涛  李俭彬 《重庆师专学报》2011,(6):106-109

我国刑法在规定司法机关对犯罪人追究刑事责任有效期限的同时,用时效中断、时效延长对追诉时效进行补充,建立了比较完善的体系。由于理论和实践对追诉时效与刑事诉讼程序之间的关系缺乏必要的关注．极少反思案件进入刑事诉讼程序后追诉时效是否继续发挥作用。本文在比较法的视野下,对追诉时效与刑事诉讼程序的关系进行尝试性的厘定,得出我国刑法追诉时效存在的缺陷,为了填补该缺陷而建议在刑法中创设追诉时效中止制度。  相似文献   

Effect of gear ratio on peak power and time to peak power in BMX cyclists     

Lee P. Rylands  Simon J. Roberts  Howard T. Hurst 《European Journal of Sport Science》2017,17(2):127-131

The aim of this study was to ascertain if gear ratio selection would have an effect on peak power and time to peak power production in elite Bicycle Motocross (BMX) cyclists. Eight male elite BMX riders volunteered for the study. Each rider performed three, 10-s maximal sprints on an Olympic standard indoor BMX track. The riders’ bicycles were fitted with a portable SRM power meter. Each rider performed the three sprints using gear ratios of 41/16, 43/16 and 45/16 tooth. The results from the 41/16 and 45/16 gear ratios were compared to the current standard 43/16 gear ratio. Statistically, significant differences were found between the gear ratios for peak power (F(2,14)?=?6.448; p?=?.010) and peak torque (F(2,14)?=?4.777; p?=?.026), but no significant difference was found for time to peak power (F(2,14)?=?0.200; p?=?.821). When comparing gear ratios, the results showed a 45/16 gear ratio elicited the highest peak power,1658?±?221?W, compared to 1436?±?129?W and 1380?±?56?W, for the 43/16 and 41/16 ratios, respectively. The time to peak power showed a 41/16 tooth gear ratio attained peak power in ?0.01?s and a 45/16 in 0.22?s compared to the 43/16. The findings of this study suggest that gear ratio choice has a significant effect on peak power production, though time to peak power output is not significantly affected. Therefore, selecting a higher gear ratio results in riders attaining higher power outputs without reducing their start time.  相似文献   

Reducing suspension for minor infraction and improving school climate perceptions among black adolescents via cultural socialization: A multi-informant longitudinal study     

《Learning and Instruction》2022

Racially disparate school disciplinary practices create inequitable circumstances for minority and immigrant youth around the world. In the U.S., Black youth are more likely than their White peers to be suspended for minor, non-violent infractions. This study explores (a) whether school cultural socialization practices reported by Black students (N = 544; M_age (SD) = 12.45 (1.57); 49% boys) and teachers (N = 38; 84% female) were linked to a reduced likelihood of receiving suspensions for minor infractions and (b) the extent to which Black students' perceptions of school climate mediated this relation. Results indicated that school cultural socialization was linked to a decreased likelihood of being suspended for a minor infraction and improved school climate perceptions for Black students. Black students’ perception of school climate mediated the link between school cultural socialization and suspensions for minor infractions. These results highlight school cultural socialization as a promising approach for increasing cultural responsivity and equity within schools, reducing racial bias, and expunging unjust disciplinary responses.  相似文献   

论皮浪的怀疑主义     

王天海 《科教文汇》2012,(1):90-90,125

皮浪通过＂悬置判断＂的方法,既不肯定判断也不否定判断,达到一种中立的状态,而不断地从事探究。随着＂悬置判断＂获得一种心灵的宁静境界,最终则是肉体的无痛苦和心灵的无纷扰的人生的幸福。皮浪处在动荡不安的社会环境中,并以怀疑主义去反对当时的种种独断论,都有着对人的深切关怀并都想获得一种宁静的心理体验。  相似文献   

基于层次分析法的大跨径缆索承重桥梁状况评估方法     

朱从明 《黑龙江科技信息》2012,(7):266-267

针对大跨径缆索承重桥梁的特点,制定了一般性评估模型。首先,利用层次分析法建立了大跨径悬索桥和斜拉桥一般性评估递阶层次模型,该模型包括部位层、构件层和损伤层三个层次,随后利用专家调查和群组决策算法确定了部位层和构件层各元素的权重。其次,为了建立损伤层各元素的权重,建立了一种称为动态调权法的权重计算公式。该方法能够较为全面地考虑大跨径缆索承重桥梁的特点,综合反映桥梁的技术状况。  相似文献