Optimal sizing of piezo-actuators for minimum-deflection design of frames under uncertain loads

Optimal piezo-actuator sizes and locations for a frame structure under bending load uncertainty are determined with the objective of minimizing the deflection under worst case of loading. The bending moments generated by the piezo-actuators are used for deflection control, i.e., to minimize the maximum deflection. The frame is subjected to a tip load which lies in an uncertainty domain with regard to its magnitude and direction. The specific uncertain loading studied in the present paper involves a load of given magnitude but of unknown direction, which should be determined to produce the highest deflection. The worst case of loading depends on the size and location of the actuators leading to a nested problem of optimization (design) and anti-optimization (uncertainty problem). Results are given for deterministic and uncertain loading conditions.     

Influence of coherent structures in the gas-particle circular cylinder wake flow

INTRODUCTION Turbulent gas-particle flows are frequently found in natural phenomena and industrial processes.Cases of cylinders in cross flows with particles occur in heat exchange equipment,including the convective zone of a fluidized-bed combustor,and in the primary superheaters,reheaters,and economizers of coal-fired boilers.Coherent structures often occur in the above-mentioned gas-particle flow,and have great effect on such different systems,while some features of tur-bulent multiphas…     

浅议英语轭式修辞格

轭式修辞格(Zeugma)是一种用法较为独特的修辞手法。由于其使用不如其它的修辞方法那么普遍，所以很少有人去注意它。本文将对这一修辞格的分类及结构作一初步探讨。     

用肯定句式表示否定意义--浅谈英语中否定意义的特殊表达法

在英语中 ,有一些句子形式上是肯定的 ,但却表达一种否定的意义。所以在阅读理解英语文章时要注意语言环境 ,注意那些形肯意否的表达方式 ,切不可望文生义。     

An Ode to Imre Lakatos: Quasi-Thought Experiments to Bridge the Ideal and Actual Mathematics Classrooms

This paper explores the wide range of mathematics content and processes that arise in the secondary classroom via the use of unusual counting problems. A universal pedagogical goal of mathematics teachers is to convey a sense of unity among seemingly diverse topics within mathematics. Such a goal can be accomplished if we could conduct classroom discourse that conveys the Lakatosian (thought-experimental) view of mathematics as that of continual conjecture-proof-refutation which involves rich mathematizing experiences. I present a pathway towards this pedagogical goal by presenting student insights into an unusual counting problem and by using these outcomes to construct ideal mathematical possibilities (content and process) for discourse. In particular, I re-construct the quasi-empirical approaches of six!4-year old students’ attempts to solve this unusual counting problem and present the possibilities for mathematizing during classroom discourse in the imaginative spirit of Imre Lakatos. The pedagogical implications for the teaching and learning of mathematics in the secondary classroom and in mathematics teacher education are discussed.     

Managing mergers — governancing institutional integration

Despite striking similarities, the adoption and implementation of policy shifts regarding higher education governance vary considerably across the globe, suggesting a mixed picture of diversification and isomorphism both within and across national higher education systems. By unpacking one particular structural reform process, this paper focuses on mergers as both a governance tool and a governance result in higher education. The paper analyzes the strategic decisions taken by Norwegian higher education institutions during 2014 in the light of a proposed national reform to merge institutions in order to enhance quality in higher education. The empirical basis of the paper consists of analyses of the commissioned self-evaluations of the higher education institutions, and the strategic choices and dilemmas they expressed. The process can be seen as organizational engineering in the sense that it emerges from the self-evaluation process, but is also subject to governancing on the part of the ministry.     

茂金属配合物[(eta5-C5H4 Si2 Me5)Mo-Br(CO)3]的电子结构研究

运用G98W，采用Lan12dz基组，对茂金属配合物[eta^5-C5H4Si2Me5)Mo-Br(CO)3]进行从头算研究，探讨配合物结构单元的稳定性，分子轨道能量，原子净电荷布局规律，以及一些前沿分子轨道的组成特征等，结果表明，标题配合物结构在能量上是稳定的，作为结构单元而存在，为茂金属配合物的合成，分子组装分析提供参考。     

工程结构中非线性动态失稳与分叉理论

In civil engineering, the nonlinear dynamic instability of structures occurs at a bifurcation point or a limit point. The instability at a bifurcation point can be analyzed with the theory of nonlinear dynamics, and that at a limit point can be discussed with the theory of elastoplasticity. In this paper, the nonlinear dynamic instability of structures was treated with mathematical and mechanical theories.The research methods for the problems of structural nonlinear dynamic stability were discussed first, and then the criterion of stability or instability of structures, the method to obtain the bifurcation point and the limit point, and the formulae of the directions of the branch solutions at a bifurcation point were elucidated. These methods can be applied to the problems of nonlinear dynamic instability of structures such as reticulated shells, space grid structures, and so on.     

如何提高英语四、六级的作文分数

写作是大学英语教学的难点之一,也是四、六级考试的重点之一。笔者认为在考试中,书写工整漂亮、词汇标新立异、造句与众不同以及布局独树一帜可以帮助考生提高四、六级的作文分数。     

Cross-Racial Interaction Among Undergraduates: Some Consequences, Causes, and Patterns

This study utilized a national longitudinal data set of college students to examine the educational relevance of cross-racial interaction and how campuses can best structure such opportunities. The general pattern of findings suggests that cross-racial interaction has positive effects on students' intellectual, social, and civic development. The results show that institutions could enhance such experiences by enrolling larger proportions of students of color and by offering students more opportunities to live and work part-time on campus. While these findings apply uniformly to white students, the frequency of cross-racial interaction does not always follow an expected path of steady gains for students of color as the student body becomes increasingly more diverse. Implications of the findings are discussed.