低应变法检测桥梁嵌岩桩的评价

用低应变法检测嵌岩桩 ,若桩底出现明显同相反射 ,多数因桩底缺陷引起。而区分是桩还是持力层的缺陷 ,主要看反射的起跳时间在 2 L/ C之前还是之后。当桩的变径及入岩反射对测试影响很大时 ,应进一步用钻芯法检验。     

男子青少年体操运动员肘、腕关节劳损性伤痛的防治

男子青少年体操运动员肘关节、腕关节劳损性伤痛是训练中的一种常见多发性运动损伤，严重阻碍了训练计划的执行和运动技术的提高。本文分析和研究了伤痛形成的各种原因，并提出了预防、治疗的基本方法。     

肌肉拉伤的临床和基础理论研究

肌肉拉伤是运动损伤中的常见病。在临床上认为,大多数肌肉拉伤是由于肌肉性质改变造成的局部损伤,可以诊断出损伤的位置,多发生于靠近肌肉—肌腱连接处的肌纤维。生物力学研究表明:当肌肉受到的拉伸力大于其最大等长收缩力时将会引起损伤。比较肌肉在被动拉伸和有神经刺激收缩的主动拉伸时发现,在损伤时拉伸力有小量增加,应变没有变化,但吸收能量的能力却有很大的变化。实验还证实了肌肉的粘弹性。这些研究成果说明:肌肉吸收能量的能力和粘弹性的改变对于预防肌肉损伤是非常重要的。     

骑马蹲裆式与髌骨劳损的预防

为探索传统武术训练中的骑马蹲裆式对髌骨劳损的预防作用，作者用积累了十年的运动损伤资料和文献，从解剖学，生物力学，运动医学的解度，论述了膝关节半蹲位诸姿势中以骑马蹲裆式其髌韧带的力臂最长，髌股关节面接触面大，髌股关节面的压应力大并有利于发展股内侧肌的力量，可以限制髌骨外移，从而预防髌骨劳损的有效方法。     

钢结构材料在高温(火灾)条件下的力学性能试验研究

从基本的钢结构材料在高温下的力学性能着手 ,进行高温条件下钢结构材料的性能试验 ,建立高温下钢材的屈服强度、极限强度、弹性模量和极限应变随温度变化的力学模型 ,为高温 (火灾 )条件下钢结构的结构分析提供依据。     

香菇菌株9907的选育及生物学特性

从怀化市及沅陵、中方、麻阳等县采集野生香菇子实体,通过分离、初筛、复筛和栽培试验,选育出一株较好的菌株香菇9907.香菇菌株9907属于低温结实型,菌丝体生长速度快,花菇率及生物学效率均较高,适合代料栽培.     

Role strain,engagement and academic achievement in early adolescence

The present study was designed to investigate the relationships between role strains following the transition to secondary school and academic achievement. Academic engagement was hypothesized to mediate between role strain and achievement. The sample consisted of 749 students in their first year of secondary school. Four types of role strain were investigated: parent, teacher, school and peer. Parent and teacher role strains appeared to be negatively associated with academic achievement, as mediated through academic engagement. Parent and school role strain were directly and negatively associated with achievement. Results are discussed in the light of parenting practices and the developmental mismatch hypothesis.     

Modeling Strain Rate Effect for Heterogeneous Brittle Materials

Rocks are heterogeneous from the point of microstructure which is of significance to their dynamic failure behavior. Both the compressive and tensile strength of rock-like materials is regarded different from the static strength. The present study adopts smoothed particle hydrodynamics (SPH) which is a virtual particle based meshfree method to investigate strain rate effect for heterogeneous brittle materials. The SPH method is capable of simulating rock fracture, free of the mesh constraint of the traditional FEM and FDM models. A pressure dependent J-H constitutive model involving heterogeneity is employed in the numerical modeling. The results show the compressive strength increases with the increase of strain rate as well as the tensile strength, which is important to the engineering design.     

再生混凝土力学性能的研究

对再生混凝土力学性能的研究进行了综述，主要包括再生混凝土力学性能的抗压强度、弹性模量、干缩与徐变。研究表明，和普通混凝土相比，再生混凝土力学性能的抗压强度低，弹性模量小，干缩与徐变较大。最后提出了再生混凝土力学性能需要进一步研究的问题。     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/