专四英语议论文写作和语篇教学

语言与思维密切相关,英汉民族各不相同的两种思维模式决定了英汉议论文的篇章结构有各自的特点。写作的目的是表达思想、实现交际。为了保证交际的顺畅进行,英语议论文理所当然应该用英语民族人的思维方式来组织结构,尽量避免汉语文章结构的负迁移。因此,在日常的英语专业写作教学中,教师很有必要努力探索语篇教学的方法并大力开展语篇教学。     

Numerical computations of the flow in a finite diverging channel

The flow in a finite diverging channel opening into a large space and resembling the experimental prototype of Putkaradze and Vorobieff （2006） was numerically investigated. The effects of the Reynolds number, initial condition, intersection angle, length of the wedge edges, and the outer boundary condition were examined. The numerical results showed that the flow in the wedge undergoes a change from symmetrical flow to unsymmetrical flow with a weak backflow, then a vortical （circulation） flow and finally an unsteady jet flow as the Reynolds number is increased for an intersection angle of 32° and a wedge edge of length 30 times the width of the inlet slit. For the unsteady flow, the jet attached to one side of the wedge constantly loses stability and rolls up into a mushroom-shaped vortex-pair near the outlet of the wedge. As the intersection angle is increased to 50°, a stable jet flow is observed as a new regime between the vortex and unsteady regimes. Both the intersection angle and the wedge length have negative effects on the stability of the flow, although the effect of the wedge length on the critical Reynolds number for the symmetry-breaking instability is not pronounced. The outer boundary condition was found not to affect the flow patterns inside the wedge significantly. At a certain Re regime above the onset of symmetry-breaking instability, the flows evolve into steady state very slowly except for the initial stage in the case of decreasing flow flux. Two different solutions can be observed within the normal observation time for the experiment, providing a possible explanation for the hysteresis phenomenon in the experiment.     

碱土金属硼酸盐聚阴离子的拓扑结构研究

从拓扑的角度出发,借助ICSD、Findit和Mercury软件,研究了碱土金属硼酸盐聚阴离子的结构特征,并简化键合模型,给出了碱土金属硼酸盐的结构预测式,从而丰富了硼酸盐结构化学,为研究硼酸盐结构与性能的关系打下了基础,对解析和预测硼酸盐的拓扑结构有所帮助。     

古籍被动结构汉英翻译研究

在汉语古籍的英译过程中,被动结构通常可以相应地使用英语中的被动语态。但由于文本的作者、译者、表达和含义之间的关系是积极的而不是随意的,因而在不少情况下,根据目的语的表达习惯和适应性原则的要求,古汉语被动结构亦可使用主动语态进行变通转译。     

主框架梁布置对巨型结构抗震受力性能的影响

运用有限元分析软件SAP2000对主框架梁位置布置不同的巨型框架结构进行地震反应的弹性时程分析．结果表明,随着巨型梁布置位置的上移,结构侧移变大,结构层间相对位移沿高度方向趋于不均匀,最大结构层间侧移发生部位逐渐上移．     

Integrating multidisciplinary engineering knowledge

In order to design two distinct engineering qualification levels for an existing University of Technology programme, empirical evidence based on the current diploma is necessary to illuminate the nature of and the relationship between the contextual and conceptual elements underpinning a multidisciplinary engineering curriculum. The increasing focus on contextual application could result in decreasing opportunities to develop the conceptual disciplinary grasp required for a dynamic, emerging region at the forefront of technological innovation. Using the theoretical tools of Bernstein and Maton to analyse final year student practice, the research addresses the question of how multidisciplinary knowledge is integrated by students, and what this reveals about the nature of such knowledge. The paper presents a conceptualisation of multidisciplinary knowledge integration practices as a dynamic process along two axes simultaneously, shifting between different forms and levels of conceptual and contextual knowledge.     

Measurement Bias Detection Through Factor Analysis

Assessing the correctness of a structural equation model is essential to avoid drawing incorrect conclusions from empirical research. In the past, the chi-square test was recommended for assessing the correctness of the model but this test has been criticized because of its sensitivity to sample size. As a reaction, an abundance of fit indexes have been developed. The result of these developments is that structural equation modeling packages are now producing a large list of fit measures. One would think that this progression has led to a clear understanding of evaluating models with respect to model misspecifications. In this article we question the validity of approaches for model evaluation based on overall goodness-of-fit indexes. The argument against such usage is that they do not provide an adequate indication of the “size” of the model's misspecification. That is, they vary dramatically with the values of incidental parameters that are unrelated with the misspecification in the model. This is illustrated using simple but fundamental models. As an alternative method of model evaluation, we suggest using the expected parameter change in combination with the modification index (MI) and the power of the MI test.     

Principles and Practice of Scaled Difference Chi-Square Testing

We highlight critical conceptual and statistical issues and how to resolve them in conducting Satorra–Bentler (SB) scaled difference chi-square tests. Concerning the original (Satorra & Bentler, 2001 Satorra, A. and Bentler, P. M. 2001. A scaled difference chi-square test statistic for moment structure analysis. Psychometrika, 66: 507–514. [Crossref], [Web of Science ®] , [Google Scholar]) and new (Satorra & Bentler, 2010 Satorra, A. and Bentler, P. M. 2010. Ensuring positiveness of the scaled chi-square test statistic. Psychometrika, 75: 243–248. [Crossref], [Web of Science ®] , [Google Scholar]) scaled difference tests, a fundamental difference exists in how to compute properly a model's scaling correction factor (c), depending on the particular structural equation modeling software used. Because of how LISREL 8 defines the SB scaled chi-square, LISREL users should compute c for each model by dividing the model's normal theory weighted least-squares (NTWLS) chi-square by its SB chi-square, to recover c accurately with both tests. EQS and Mplus users, in contrast, should divide the model's maximum likelihood (ML) chi-square by its SB chi-square to recover c. Because ML estimation does not minimize the NTWLS chi-square, however, it can produce a negative difference in nested NTWLS chi-square values. Thus, we recommend the standard practice of testing the scaled difference in ML chi-square values for models M ₁ and M ₀ (after properly recovering c for each model), to avoid an inadmissible test numerator. We illustrate the difference in computations across software programs for the original and new scaled tests and provide LISREL, EQS, and Mplus syntax in both single- and multiple-group form for specifying the model M ₁₀ that is involved in the new test.     

开发区建设与城市经济空间结构演变研究

开发区作为一个特殊的城市空间和带动经济发展的重要极核,对城市经济发展和经济空间结构的影响日益显著。结合开发区对城市的经济贡献,根据开发区成长的时间顺序,提出了开发区建设与城市发展之间的三种经济关系：依赖、互动、反哺。并在此基础上。从城市经济活动的分散化、集中化、多中心网络化等方面,较为系统地探讨了在开发区的影响下城市经济空间结构的演变。