The Application of Cohesion and Coherence Theory in Advanced College English Teaching

In 1976,Halliday and Hassan put forward the concept of cohesion and coherence theory for the first time in their book English Cohesion and discussed five types of cohesion:reference,substitution,omission,conjunction and lexical cohesion.Some scholars enriched and expanded cohesion and coherence from the perspective of cohesion conditions,phonology,structural relations at the level of meaning and discourse.Predecessors pay much attention to the theoretical discussion,while from the perspective of the theoretical application,the cohesion and coherence theory is used for analyzing the advanced college English textbook to provide the guidance for teachers and students in teaching and learning-teachers can judge and adopt appropriate teaching methods according to the cohesion and coherence theory;Students can understand cohesion and coherence in the text as well as the influencing factors,and adequately use the cohesion and coherence mechanism in listening,speaking,reading and writing.

Survey Research into Cohesive Device Misuses in Business English Writing

Cohesive devices in students’business English writing are regarded as the object of the research.Based on Haliday and Hasan’s cohesion theory,this paper introduces commonly-used cohesive devices in English writing.With the method of quantitative data,use and misuse frequency of cohesive devices in students’writings can be known.The paper will also analyze why misuses happen through qualitative data analysis and explore right ways of using cohesive devices.

A Study on Semantic Relations of“and”Used in Chinese EFL Learners’Narrative Writing

Studies on conjunctions used by Chinese English as a Foreign Language(EFL)learners over the past ten years have focused mainly on the use of conjunctions in argumentative writing,and there is little empirical work on conjunction“and”in narrative writing.The purpose of this paper is to explore the characteristics of the semantic relations of“and”used in the narrative writing of Chinese EFL learners from the perspective of text coherence.Through analysis of narrative writing of 29 sophomores,this study investigates the characteristics of semantic relations expressed by the conjunction“and”and the differences in the use of semantic relations of“and”between high-score and low-score writing.The results show different frequencies of the use of semantic relations of“and”.ELF learners prefer to use the term“and”to build progressive relation and parallel relation more than any other relation.Both high-score and low-score writing use a sizable number of“and”to build progressive relation and parallel relation,but high-score writing obviously contains more guiding relations and fewer supplementary relations.These findings have some pedagogical implications for teaching transitions.

Fracture behavior and self-sharpening mechanisms of polycrystalline cubic boron nitride in grinding based on cohesive element method

Unlike monocrystalline cubic boron nitride(CBN), polycrystalline CBN(PCBN) shows not only higher fracture resistance induced by tool-workpiece interaction but also better selfsharpening capability;therefore, efforts have been devoted to the study of PCBN applications in manufacturing engineering. Most of the studies, however, remain qualitative due to difficulties in experimental observations and theoretical modeling and provide limited in-depth understanding of the self-sharpening behavior/mechanism. To fill this research gap, the present study investigates the self-sharpening process of PCBN abrasives in grinding and analyzes the macro-scale fracture behavior and highly localized micro-scale crack propagation in detail. The widely employed finite element(FE) method, together with the classic Voronoi diagram and cohesive element technique,is used considering the pronounced success of FE applications in polycrystalline material modeling.Grinding trials with careful observation of the PCBN abrasive morphologies are performed to validate the proposed method. The self-sharpening details, including fracture morphology, grinding force, strain energy, and damage dissipation energy, are studied. The effects of maximum grain cut depths(MGCDs) and grinding speeds on the PCBN fracture behavior are discussed, and their optimum ranges for preferable PCBN self-sharpening performance are suggested.