Pr阶循环群的整群环的极大Z-序

对pr阶循环群讨论了它们的整群环ZG在QG中的极大的Z-序Γ,给出了Γ的具体表达式。     

Creatine co-ingestion with carbohydrate or cinnamon extract provides no added benefit to anaerobic performance

The insulin response following carbohydrate ingestion enhances creatine transport into muscle. Cinnamon extract is promoted to have insulin-like effects, therefore this study examined if creatine co-ingestion with carbohydrates or cinnamon extract improved anaerobic capacity, muscular strength, and muscular endurance. Active young males (n?=?25; 23.7?±?2.5?y) were stratified into 3 groups: (1) creatine only (CRE); (2) creatine+ 70?g carbohydrate (CHO); or (3) creatine+ 500?mg cinnamon extract (CIN), based on anaerobic capacity (peak power·kg^?1) and muscular strength at baseline. Three weeks of supplementation consisted of a 5?d loading phase (20?g/d) and a 16?d maintenance phase (5?g/d). Pre- and post-supplementation measures included a 30-s Wingate and a 30-s maximal running test (on a self-propelled treadmill) for anaerobic capacity. Muscular strength was measured as the one-repetition maximum 1-RM for chest, back, quadriceps, hamstrings, and leg press. Additional sets of the number of repetitions performed at 60% 1-RM until fatigue measured muscular endurance. All three groups significantly improved Wingate relative peak power (CRE: 15.4% P?=?.004; CHO: 14.6% P?=?.004; CIN: 15.7%, P?=?.003), and muscular strength for chest (CRE: 6.6% P?P?P?P?P?P?P?=?.013; CHO: 10.0% P?=?.007; CIN: 17.3% P?P?=?.021) and CIN (15.5%, P?相似文献   

转子绕组故障感应电机转矩和转速的计算

基于多回路方法,对异步电机定子电流、转矩、转速进行了分析,对转子绕组故障引起的电机转矩、转速的波动进行了深入研究,提出了波动计算模型.仿真与计算结果表明:转子绕组故障引起电机转矩、转速波动;波动分量的大小、频率可定量计算;转矩与转速波动的频率相等,波动的幅值随转子绕组故障严重程度增加而增加;负载转动惯量对电机转矩、转速有较大的影响,负载转动惯量增加,转矩波动分量的幅值增加而转速波动分量的幅值减小.     

Effect of the racket mass and the rate of strokes on kinematics and kinetics in the table tennis topspin backhand

The purpose of this study was to investigate the effect of the racket mass and the rate of strokes on the kinematics and kinetics of the trunk and the racket arm in the table tennis topspin backhand. Eight male Division I collegiate table tennis players hit topspin backhands against topspin balls projected at 75 balls · min^?1 and 35 balls · min^?1 using three rackets varying in mass of 153.5, 176 and 201.5 g. A motion capture system was used to obtain trunk and racket arm motion data. The joint torques of the racket arm were determined using inverse dynamics. The racket mass did not significantly affect all the trunk and racket arm kinematics and kinetics examined except for the wrist dorsiflexion torque, which was significantly larger for the large mass racket than for the small mass racket. The racket speed at impact was significantly lower for the high ball frequency than for the low ball frequency. This was probably because pelvis and upper trunk axial rotations tended to be more restricted for the high ball frequency. The result highlights one of the advantages of playing close to the table and making the rally speed fast.     

树的谱半径的排序

对树的谱半径按照从大到小的顺序进行了排序,给出了谱半径第十四大到第三十二大的树,并给出了树的谱半径的一个新上界.     

一类算子方程最小最大耦合拟解的存在性

利用半序的方法,研究了巴拿赫空间(Banach space)中一类非线性算子方程的最小最大耦合拟解.在得到的存在性定理中,减弱了方程中算子的连续性,同时对锥的性质未作限制,其结论具有更广的适用范围.     

软启动器及其在给水泵中的应用

针对企业常用的笼型异步电机工况，通过分析软起动器的工作原理及常用的几种起动方式，阐述了软起动器的使用、选型时应注意事项。     

网络编码综述

网络编码是近年来通信领域的重大突破,本文在介绍网络编码基本原理的基础上,阐述了网络编码的优缺点、分类、应用和发展趋势。     

LiBr溶液浓度自动测量系统研制

在现有手动天平测量原理的基础上,设计了能实现自动快速测量的LiBr溶液浓度测量系统,该系统基于电磁力矩反馈平衡原理测量出LiBr溶液的密度,同时测量出溶液的温度,计算机根据溶液的浓度与密度及温度的关系自动计算出被测溶液的浓度。给出了电磁力矩反馈平衡测量系统工作原理,设计了系统各组成部分,并进行了相关的实验研究。理论研究和实验结果均表明,通过该系统可实现降膜后LiBr溶液浓度高精度自动快速测量,且能实现高精度测量的要求。     

最大摄氧量间接测定ACSM法与一步台阶实验的比较研究

本文采用实验法、数据统计法和对比法,对最大摄氧量其间接测定方法进行了探讨分析。通过比较研究最大摄氧量间接测定ACSM法与一步台阶实验法,有利于从测试的精确度、简易性、效率、费用及训练评价效果方面提供更好的健身理论依据。