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841.
黄河上中游降水正态性与稳定性分析 总被引:1,自引:0,他引:1
基于1961-2011年黄河上中游45站年、月降水量资料,利用偏态(峰度)系数、变差系数、皮尔逊Ⅲ型分布等统计方法,对该区降水量进行正态性和稳定性分析,并拟合不同保证率下的年降水量及百年重现期.结果表明:年降水量有33.3%的台站未通过正态性检验.月降水量冬季各月几乎所有台站均不服从正态分布,夏季各月降水量正态性略好,但未通过正态性检验站数也在60%以上.对降水量进行非线性变换后的正态化效率达95.4%,其中1月、2月、3月平方根法优于立方根法,11月、12月反之,其余月份基本相同.降水稳定性冬季最差,春季次之,夏、秋季最好,从区域看,青海高原东部降水稳定性最好,河套北部最差.P=50%和P=80%保证率下的降水量自东南向西北递减,前者接近平均值,后者远低于平均值.有21个台站年降水量历史极大值突破了百年一遇,与年降水量未通过正态性检验的台站基本对应,主要集中在陇中-陇东-宁夏南部地区,该区域属于气候变化的敏感区和极端降水事件的多发区. 相似文献
842.
随着电子信息技术的发展,地理信息系统(GIS)的应用越来越多,本文采用OpenGL显示标准格式mif的矢量地图,并应用于雷达终端显示工程实践,和传统采用VC绘图函数绘制矢量地图相比,采用OpenGL绘制速度更快,效果更好. 相似文献
843.
兴奋剂问题的高学历化倾向日益引起社会对高校竞技运动发展的担忧,而针对高校兴奋剂问题的干预,将其关在规则的牢笼里具有重要的社会价值和现实意义。本研究基于双态度理论模型,采用自我报告和IAT实验深入地分析高校运动员兴奋剂使用的内在驱动机制和容忍度,并提出侧重高校大学生认知和行为层面的干预,强化其规则意识以及降低其对兴奋剂的容忍度是促进高校竞技体育回归本原的重要着力点,进而更好的实现运动员、竞技体育和整个社会的和谐发展。 相似文献
844.
陈华国 《河北体育学院学报》2013,(4):75-78
以前期研究中初步构建的大众跆拳道教练员胜任特征模型为基础编写评价量表测试条目,经过条目筛选、项目分析后初步形成初测量表;再经过探索性因素分析确定了量表的因素结构,经过验证性因素分析检验其因素结构效度,并检验了量表的信度和实证效度。结果表明:量表具有较好的结构效度和信度,能有效区分优秀组与一般组教练员。 相似文献
845.
程勇 《军事体育进修学院学报》2013,(1):64-66
4×10m往返跑是人民警察入职体测中的必测项目,其技术动作包括起跑加速、急停、换取木决、转身加速等环节。通过测试成绩与分析技术特点认为:受测者应根据自身能力特点确定适合的起跑姿势并采用合理加速技术迅速起跑提速;形成右脚在前制动,身体侧对端线的急停姿势;运用稳定性较强的双手同时换取木块技术以提高成绩;并在有效急停和换取木块基础上,完成同步转身和加速动作。 相似文献
846.
李云姝 《包头职业技术学院学报》2013,(3):69-70
生物学教学中直观性手段的重要性已得到广大师生的公认,其中模拟实验就是生物教学中的一个重要手段.它搭起了微观与宏观的桥梁,能提高教学效果,并能使学生快速入门,可化解生物教学中的难题. 相似文献
847.
Jess Rasmussen Birgitte Hanel Kari Saunamaki Niels H. Secher 《Journal of sports sciences》2013,31(6):525-531
Abstract Pulmonary diffusing capacity (Dlco), together with spirometric variables, arterial oxygen tension (paO2) and cardiac output were determined before and at intervals after maximal arm cranking, treadmill running and erogmeter rowing. Independent of the type of exercise, Dlco increased immediately post‐exercise from a median 13.6 (range 7.3–16.3) to 15.1 (9.3–19.6) mmol min‐1 kPa‐1 (P <0.01). However, it decreased to 11.6 (6.9–15.5) mmol min‐1 kPa‐1 (P <0.01) after 24 h with cardiac output and paO2 at resting values, and Dlco normalized after 20 h. Thoracic electrical impedance at 2.5 and 100 kHz increased slightly post‐exercise, indicating a decrease in thoracic fluid balance, and there were no echocardiographic signs of left ventricular failure at the time of the decrease in Dlco. Also, active muscle (limb) circumference and volume, and an increase in haematocrit from 43.8 (38.0–47.0) to 47.1 (42.7–49.8) (P <0.01), had normalized at the time of the decrease in Dlco. Vital capacity, forced vital capacity, forced expiratory volume in 1 s, peak and peak mid‐expiratory flows did not change. However, total lung capacity increased from 6.8 (5.0–7.6) to 7.0 (5.1–7.8) litres (P <0.05) immediately after exercise and remained elevated at 6.9 (5.1–8.7) litres (P <0.05) when a decrease in Dlco was noted. The results demonstrate that independent of the type of maximal exercise, an approximate 15% reduction in Dlco takes place 2–3 h post‐exercise, which normalizes during the following day of recovery. 相似文献
848.
David Shaun Bryant Fredric L. Goss PhD Robert J. Robertson Kenneth F. Metz David S. Feingold 《Research quarterly for exercise and sport》2013,84(3):300-304
Abstract The purpose of this investigation was to compare the peak physiological responses among four protocols that employed different amounts of handweighted exercise in 16 males (aged 26.3 ± 4.1 years). The four protocols were (a) uphill treadmill running (UR; 3.36 m-s1, 2.5% grade increase-3 min1); (b) uphill treadmill walking while pumping 1.36kg handweights (HW) (UWHW; 1.79ms1, 5.0% grade increase-3 min1; (c) treadmill walking while pumping .91-kg HW (WHW; 1.79 m-s1, 0% grade, .91kg HW increase-3 min1); and (d) standing in place and pumping HW (SHW; arm work as described in WHW). It was hypothesized that the peak responses would be inversely proportional to the estimated muscle mass activated (i.e., UR = UWHW > WHW > SHW). Dependent variables included peak oxygen uptake (VO2 peak), peak heart rate (HRpeak), peak ventilation (Vepeak), and peak respiratory exchange ratio (RERpeak). No differences were noted between UR and UWHW with respect to any of the dependent variables. All variables (except RERpeak) were greater (p < .01) in UR and UWHW than either WHW or SHW. RERpeak was greater (p < .01) in UR and UWHW than in WHW. VO2peak and HRpeak were greater (p < .01) in WHW when compared to SHW. Mean VO2peak was 97.5, 69.7, and 60% of UR for UWHW, WHW, and SHW, respectively. Therefore, walking and pumping handweights provides a maximal stimulus to the oxygen transport system. 相似文献
849.
Abstract Cinematographical analysis was used to compare spatial and temporal relationships of ten skilled and ten non-skilled performances of the standing broad jump. Means of the extent and duration of major joint action for the two levels of skill were represented graphically. Characteristic likenesses appeared in the general patterns of movement of limbs and in proportion of time consumed by the phases of the movement. Characteristic differences were found in angles of take-off and of landing and in extent and duration of specific joint actions. Greater extent of movement occurred in the skilled performances. The latter characteristically used more time in hip flexion and less time in knee extension. 相似文献
850.
Jo Ann Kollath Margaret J. Safrit Weimo Zhu Long-Guang Gao 《Research quarterly for exercise and sport》2013,84(4):432-435
In a review of 46 meta-analyses of gender differences, overhand throwing had the largest gender difference favoring boys (ES > 3.0). Expectations for gender-specific performances may be less pronounced in female Australian Aborigines, because historical accounts state they threw for defense and hunting. Overhand throwing velocities and kinematics were recorded in 30 female and male Aboriginal Australian children 6-10 years old. Results indicated the Aboriginal girls and boys were more similar in horizontal ball velocities than U.S. girls and boys. Throwing kinematics between girls and boys were also more similar in Australian Aborigines than U.S. children. Aboriginal girls threw with greater velocities than U.S., German, Japanese, and Thai girls, while the boys were similar across cultures. 相似文献