On optimal form of arches

This paper considers the problem of optimal shaping of arches subjected to general loading. The investigation comprises the search for the optimum centerline form as well as the optimum area distribution along the arch. As objective function and constraints, the appropriate combinations of arch thrust, material volume, total arc length, and enclosed area are considered.     

On a special form of the cauchy-schwarz inequality

This paper deals with questions concerning a transformation-based form of the Cauchy-Schwarz inequality (f,f)(g,g) ? (f,g)(g,f) where f and g are complex vectors. In the case of a linear transformation restricted to be real a refinement of the inequality can be given. The classes of transformation matrices are defined which impose the equality signs in the above inequalities and thus minimize their left hand sides. A diagonalization procedure provides the determination of a special canonical solution to the desired linear transformation and enables the explicit definition of the remaining degree of freedom.     

增强雷电防护意识 减少雷电灾害

西藏是雷电灾害的多发区之一,据自治区雷电防护中心调查收集的数据显示,我区每年雷电灾害造成的人员伤亡事故及造成的经济损失很大。     

从心理语言学的视角看外语学习中词汇僵化的形成机制

一个词汇项的组成要素分为lemma和lexeme,lemma包括语义和句法两方面的规范,lexeme包括语型学和形式两方面的规范。词汇心理表象的发展分为三个阶段:形式阶段、母语词条媒介阶段和外语融合阶段。外语学习过程中,多数词汇项或者多数学习者都难以达到理想的第三阶段,第二阶段的母语媒介作用妨碍或者阻滞了词汇心理表象的顺利发展,往往在进入第三阶段之前就出现了中止现象,从而造成外语学习中的词汇僵化。