西部地区少数民族学生生长速度的动态变化及其环境影响因素   总被引：1，自引：0，他引：1  

张天成  白晋湘 《中国体育科技》2008,44(6)

利用西部地区少数民族学生1985年和2005年体质健康状况调研所获得的数据,对该地区少数民族学生身体形态的生长速度、青春突增期、增长速度高峰及最大年增长值的变化做20年的纵向分析和横向比较,并结合环境因素探讨该地区少数民族学生生长速度变化的特点、规律、趋势及存在的差异和原因.  相似文献   

企业的内涵增长率和可持续增长率     

谷茂春 《甘肃广播电视大学学报》2005,15(4):41-44

介绍了内涵增长率和可持续增长率的含义，通过实例数据对比验证了在内涵增长率、可持续增长率和某种实际增长率情况下销售增长对企业资本结构和长期发展的影响。得出结论企业必须选择适当的发展速度，可持续增长率是企业发展速度的参照。  相似文献   

停止课外训练对小学女生最大心率的影响   总被引：1，自引：0，他引：1  

曹红仙  叶卫兵 《体育科技文献通报》2006,14(2):12-13

以探讨小学生最大心率水平和停止课外训练对小学生最大心率的影响为目的。采取的方法是在跑台上运用Bruce法对停训8周前后的8名小学女生最大心率进行比较,并运用文献资料法,对比国内外学者在停训前后最大心率的研究。结果表明,小学女生停训前后的最大心率、运动能力均无显著差异;用传统的220-年龄推算最大心率可能不准确。  相似文献   

篮球比赛中罚球过程的心理分析及训练     

于佳祥 《哈尔滨体育学院学报》2002,20(3):56-57

对篮球比赛罚球过程中运动员的心理特征进行了简要分析，并提出了临场心理状态的调试方法和训练方法，供同仁研究参考。  相似文献   

赛艇运动员稳态心率的研究   总被引：3，自引：0，他引：3  

刘卫平  杜忠林 《湖北体育科技》2002,21(4):411-413

探讨了赛艇运动员在赛艇测功仪上作中等强度匀速运动时的稳态心率。  相似文献   

远距离单手肩上投篮训练方法探讨   总被引：1，自引：0，他引：1  

李国立 《体育学刊》2005,12(4):113-114

讨论影响投篮命中率有7个因素:手法、瞄准的方向、球的旋转、抛物线、协调性、判断反应和心理因素,并提出提高远距离投篮命中率的训练方法.  相似文献   

Ecological Study of Graduation Rates and GPA in a Library Credit Course     

Christina Heady  Megan M. Morrison  Joshua Vossler 《The Journal of Academic Librarianship》2018,44(5):642-649

The purpose of this ecological study was to examine the impact of a library credit course on graduation rates and GPA using pre-existing records. Over 20?years of aggregate institutional data were analyzed to evaluate the course's impact on first-time-full-time, white, and black students. Results were mixed: students who took the course were less likely to graduate than their peers who did not take the course but enjoyed slightly higher GPAs at graduation. It was discovered that students taking the course are not representative of the overall student body and struggle academically. Implications for revisions to the library credit course are discussed.  相似文献   

高校图书馆“毕业季”延伸服务的调查与思考     

罗亚泓 《图书情报工作》2018,62(1):88-95

[目的/意义] 毕业生是高校图书馆的特定用户之一,对"毕业季"延伸服务和活动进行调查与分析,可为相关实践工作提供参考。[方法/过程] 对2017年高校图书馆"毕业季"延伸服务和活动的网页新闻发布、微信推送情况进行抽样调查,并分析其总体特点。[结果/结论] 从专项经费和运营团队、馆员的情感与精力、经典项目、创意服务、与校友延伸服务对接、品牌化与推广方面,提出改进高校图书馆"毕业季"延伸服务的建议。  相似文献   

废蚕丝中提取丝胶工艺研究     

蓝建京  甘配芳 《河池学院学报》2011,31(5):56-60

通过对透析法、酸析法和冰冻法提取丝胶效果的比较,得出冰冻法是提取丝胶的较好的方法,其最佳的提取条件是:pH=4,-20℃,冰冻时间为13 h,丝胶液浓度为32.8%。  相似文献   

Maximal heart rate declines linearly with age independent of cardiorespiratory fitness levels     

Cemal Ozemek  Mitchell H. Whaley  W. Holmes Finch  Leonard A. Kaminsky 《European Journal of Sport Science》2017,17(5):563-570

There have been many conflicting observations between the linear or curvilinear decline in maximal heart rate (HR_max) with age. The aim of this study was to determine if linear or curvilinear equations would better describe the decline in HR_max with age in individuals of differing cardiorespiratory fitness (CRF) levels. Treadmill cardiopulmonary exercise test (CPX) results from participants (1510 men and 1134 women; 18–76 years) free of overt cardiovascular disease were retrospectively examined using cross-sectional and longitudinal study designs. Participants completing ≥2 CPX with ≥1 year between test dates were included in the longitudinal analysis (325 men and 150 women). Linear and quadratic regressions were applied to age and HR_max for the whole cohort and respective CRF groups (high, moderate, and low, relative to age and gender normative values). To test for differences among linear, quadratic, and polynomial equations, the change in R² (cross-sectional analysis) and Bayesian information criterion (BIC) (longitudinal analysis) from the linear to the more complex models were calculated. The quadratic or polynomial regression in the cross-sectional analysis, marginally improved the variance in HR_max explained by age compared to the linear regression for the whole cohort (0.2%), moderate fit group (0.3%), and low fit group (0.8%). With no improvements in the high fit group. BIC did not improve for any CRF category in the longitudinal analysis. In conclusion, the minimal differences among linear, quadratic, and polynomial equations in the respective CRF groups, emphasizes the use of linear prediction equations to estimate HR_max.  相似文献