Magnetic Properties of Nanocrystalline Fe_(60)Cr_(40) Powders Prepared by Mechanical Alloying in Vacuum and Air

1　Introduction　Sincethediscoveryofgiantmagnetoresistance(GMR),magneticmaterialswithrandommixtureofferromagneticandantiferromagneticpropertieshaverecentlyrecievedalotofattention[1].ThemagneticpropertiesofFeandCrarequitedifferentfromeachother.Feisferromagneticbelow1043K,whileCrisantiferromagneticatroomtemperature.GMRexistesnotonlyinsandwichandmultilayerfilms,butalsoinothernanostructuralmaterials,suchasgranularfilmsandnanostructurebulkmaterialspreparedbymechanicalalloying(MA).MAhasbeendev…     

高校体育师资的培养与激励导向的选择

高校体育的发展必须树立“以人为本”的管理思想，现代管理的核心是人及人的积极性，科学的管理和激励机制是体育教师队伍素质发展的关键。激励是管理过程中达成目标的催化剂，科学的管理机制必须明确激励导向，体育管理环境的优化离不开体育教育观念的转变，在此基础上，提出了转化体育管理环境的建议。     

西林小学少儿男子乒乓球运动员专项素质与技术综合评价研究

为探索一条乒乓球传统运动学校少儿男子运动员训练的成功经验，本研究选择了14项专项素质和技术指标进行研究，运用聚类分析找出影响少儿运动员专项素质和技术的典型指标，计算典型指标中的专项素质和技术的权重值(Ri)，得出专项素质和技术在训练中所应占的百分比，制定出一套对典型指标进行单因素评价和多因素综合评价模型，为传统学校少儿乒乓球运动的科学训练和选材评价提供科学、客观的依据。     

Acquiring an attacking forehand drive: the effects of static and dynamic environmental conditions

Two groups of 10 novice subjects each were trained to perform attacking forehand drives in table tennis and land the balls as fast and as accurately as possible onto a target on the opposite side of the net under two different training conditions. Under the static training condition, the balls were to be struck from a constant position, and under the dynamic training condition, balls approached the subjects in a normal way. Both groups were tested under dynamic conditions prior to and after four days of training, during which they received 1,600 practice trials. Both groups of subjects were shown to increase the number of balls that landed on the target, and learning was also evident from an increased consistency of the direction of travel of the bat at the moment of ball/bat contact. However, no increase in consistency was found for the location of the bat at the moment of ball/bat contact and for the movement times. Thus, learning can occur in the absence of externally generated time-to-contact information, but this is not due to the establishment of a consistent movement form. Learning appears to progress from control at the moment of ball/bat contact backward, toward the moment of initiation.