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1.
Cedric Morio Violaine Sevrez Pascale Chavet Eric Berton Caroline Nicol 《Journal of sports sciences》2016,34(8):738-745
In habitually shod recreational runners, we studied the combined influence of footwear and stretch-shortening cycle (SSC) fatigue on treadmill running pattern, paying special attention to neuro-mechanical adjustments in the acute and 2-day delayed recovery periods. The SSC exercise consisted of a series of 25 sub-maximal rebounds on a sledge apparatus repeated until exhaustion. The acute and delayed functional fatigue effects were quantified in a maximal drop jump test. The neuro-mechanical adjustments to fatigue were examined during two submaximal treadmill run tests of 3 min performed either barefoot or with shoes on. Surface electromyographic (EMG) activities, tibial accelerations and kinematics of the right lower limb were recorded during the first and last 15 s of each run. The main result was that neuro-mechanical differences between the shod and barefoot running patterns, classically reported in the absence of fatigue, persisted in the fatigued state. However, in the delayed recovery phase, rearfoot eversion was found to significantly increase in the shod condition. This specific footwear effect is considered as a potential risk factor of overuse injuries in longer runs. Therefore, specific care should be addressed in the delayed recovery phase of SSC fatigue and the use of motion control shoes could be of interest. 相似文献
2.
牵拉-缩短周期(SSC)作为一种重要的快速力量表现形式,在大部分运动项目中起着重要作用。但是对不同运动速度及负荷下SSC活动的力学特性,目前的研究还不是太清楚。以19位快速力量项目运动员为试验对象,通过Kistler三维测力系统,研究在不同速度和不同负荷SSC练习中下肢肌肉活动的力学特性。结果表明,慢速牵拉-缩短周期和快速牵拉缩短周期在最大反作用力值、蹬地时间、腾空时间等方面表现出很大不同(P<0.05);而且不同负荷快速牵拉-缩短周期活动时下肢肌肉力学特性之间又有着显著差异(P<0.05)。说明在不同强度的SSC活动中神经肌肉系统有着不同的作用机制,应按照其不同的力学特性选择适宜的牵拉-缩短周期练习方法。 相似文献
3.
负重振动练习与超等长练习对下肢力量影响的比较研究 总被引：1，自引：0，他引：1
负重振动练习法是一种集中体现下肢肌群快速离心-向心收缩(StrengthShorteningCycle-SSC)工作特点的力量训练方法。通过运用三维测力手段,将负重振动练习与超等长跳深练习进行比较来揭示它的特征。结果发现和超等长跳深练习相比,负重振动练习对于下肢最大力量素质的提高幅度大于超等长跳深练习;前者对于反应力量改变无影响,而后者对其有着明显改善;两者对于下肢快速力量素质都有相同幅度的提高;两者对于下肢力量耐力素质均无明显提高。 相似文献
4.
本文阐述了基于AT91RM9200微控制器的同步串行控制器配置原理。通过典型的例子详细介绍了SSC的配置过程。SSC支持用于音频或高速串行链接的几种串行通信模式。 相似文献
5.
研究了一种扩谱载波数字脉冲间隔调制SSC—DPIM(Spread spectrum carrier digital pulse interval modulation)技术并用于电力线载波扩谱通信系统．采用线性扫频SSC扩谱载波对DPIM符号进行编码，引入脉冲前导码作为传输数据块的同步信号以防止差错传播．介绍了数据传输速率及数据块传送差错率的理论分析结果．并采用单片机实现了SSC-DPIM电力线载波通信系统．实验结果表明，在同样的电力线网络环境下，其通信效果明显优于已有的电力线载波通信系统。 相似文献
6.
系统介绍了MTS材料试验机在评价油井管抗应力腐蚀开裂性能领域中的应用。通过实测双悬臂梁试样(DCB)加载-卸载柔度闭环曲线可以建立卸载柔度系数与裂纹长度的对应关系,实现了在疲劳预裂时对DCB试样裂纹扩展的有效测控。此外,对硫化物应力腐蚀试验(SSC)后的DCB试样进行加载-楔劈移除-卸载控制与二次疲劳裂纹扩展,可获得楔劈加载的平衡载荷与SSC诱导裂纹扩展量,从而准确测定材料的K1SSC指标。 相似文献
7.
Kim-seng Chia Herlina Abdul Rahim Ruzairi Abdul Rahim 《Journal of Zhejiang University. Science. B》2012,13(2):145-151
Visible and near infrared spectroscopy is a non-destructive, green, and rapid technology that can be utilized to estimate
the components of interest without conditioning it, as compared with classical analytical methods. The objective of this paper
is to compare the performance of artificial neural network (ANN) (a nonlinear model) and principal component regression (PCR)
(a linear model) based on visible and shortwave near infrared (VIS-SWNIR) (400–1000 nm) spectra in the non-destructive soluble
solids content measurement of an apple. First, we used multiplicative scattering correction to pre-process the spectral data.
Second, PCR was applied to estimate the optimal number of input variables. Third, the input variables with an optimal amount
were used as the inputs of both multiple linear regression and ANN models. The initial weights and the number of hidden neurons
were adjusted to optimize the performance of ANN. Findings suggest that the predictive performance of ANN with two hidden
neurons outperforms that of PCR. 相似文献
8.
A single screw compressor （SSC） is an important component found in many refrigeration systems. However, the durability is not so good because of the friction between its meshing pair. Therefore the column envelope meshing pair was pro- posed to prolong the operating life of SSCs, although it has not been applied to commercial refrigeration systems. To accelerate the industrial application, a mathematical model for analyzing the column envelope meshing pair is established based on the geometry and kinematics. Equations giving the flanks of column envelope grooves are obtained, and teeth flank meshing with the groove is designed. Results show that this model could be applicable in the design of the column envelope type SSC. 相似文献
9.
基于光谱技术的苹果糖度快速无损检测研究 总被引：2，自引：0，他引：2
论文以＂红富士苹果＂为样品,研究可见/近红外光谱技术进行苹果糖度的无损检测方法。选取30个苹果,用漫反射方式获取苹果的光谱曲线,用WAY-2S数字阿贝折射仪测量苹果的糖度,对光谱曲线进行平滑和消除噪声预处理后,用偏最小二乘法（PLS）对糖度建立相应的光谱预测模型。结果表明,糖度的模型稳定性较好,相关系数r达到了0.869,说明可见/近红外光谱技术可以进行苹果糖度的检测。 相似文献
10.
肌肉拉长—缩短周期研究的若干问题 总被引：4，自引：0，他引：4
肌肉的“拉长一缩短周期”一直是运动生物力学和肌肉力学研究的热门课题,长期以来存在不同的观点和解释,本文对国际上该领域的研究进展进行综述,以引起我国生物力学工作者的关注与深入研究。 相似文献