1. 研究目的与意义（文献综述包含参考文献）1. IntroductionWith the development of science and technology, international exchanges are becoming increasingly frequent. Therefore, it requires us to have good language communication skills, including listening, speaking, reading, writing and translating. Listening is the premise and foundation for language communication, and it plays a crucial role in the development of English learners comprehensive ability. However, due to the complexity of English learning, English learners are easily affected by some emotional factors, such as motivation, attitude, anxiety, etc. Among all these affective factors, anxiety is regarded as one of the most influential factors. Therefore, it is necessary to attach importance to the impact of anxiety on English learning. Many researchers have found that English listening anxiety have great impact on EFL learners. While English majors are also struggling with English listening anxiety especiall

1. 研究目的与意义（文献综述包含参考文献）Effects of Working Memory and Different Modalities on Chinese EFL Learners#8217; Listening Comprehension 工作记忆和不同听力材料对中国英语学习者听力理解的影响 1. Introduction Nowadays, EFL education in China puts emphasis on listening, but the listening comprehension proficiency of average college students is not good. Therefore a research on the listening process and comprehension is very important. Many studies reveal that working memory is of importance in reading comprehension and writing. However, the relation between working memory and listening comprehension has not been well explored. At the same time, duo to the increasing use of video materials in listening teaching, it is also essential for us to study whether different modalities have any effect on listening comprehension. In light of the debates on the effect of working memory and different modalities on EFL learners#8217; listening compre

1. 研究目的与意义（文献综述包含参考文献）2. Literature Review 2.1 Theoretical issues 2.1.1 Listening anxiety For some time, educators have recognized the existence of foreign language anxiety and its potential for significant interference with language learning and production. In 1986, Horwitz, Horwitz, and Cope defined FL anxiety as ”a distinct complex of self-perceptions, beliefs, feelings, and behaviors related to classroom language learning arising from the uniqueness of the language learning process” (p. 128). In fact, it is widely accepted that anxiety plays a crucial role while learning a foreign language. The impact of such an emotional arousal in language learning has long been considered in language classroom. Much of the past studies have been conducted on the aspect of anxiety associated with oral production in L2; however, recently interest has been extended to cover all language skills (Kimura, 2008). One of these skills is listening. During listeni

1. 研究目的与意义（文献综述包含参考文献）2. Literature Review In the past ten years, many expects studied about the relationship between the metacognitive awareness and L2 listening performance, so this part will introduce their studies and begin with the definition of the metacognitive awareness and L2 listening performance as well as the empirical studies. 2.1 Definition of Metacognitive Awareness Metacognitive awareness is the most complex constructs, it refers to higher order thinking and includes active control over cognitive processes in learning. Anderson defined it as ”Thinking about thinking”. Without metacognitive awareness, students are left high and dry lacking any plan for how to start or monitor their performance and deprived of command over their achievements so that they lose future learning advantages (O#8217;Malley amp; Chamot, 1990). However, some language scholars believe that students#8217; listening skills have nothing to do with metacogi

1. 研究目的与意义（文献综述） 1. Background The hydraulicbrake was first invented and went on to a patent by Malcolm Lougheed in 1917,Fred Duesenberg used the Lockheed hydraulic brake on his racing cars in 1914,and Deusenberg first used the hydraulic brake on a passenger car. Thistechnology then was developed as the self-energizing hydraulic drum brakesystem in automotive industry and it is still widely used nowadays. Thehydraulic brake has been widely applied on road vehicles in recent years, andit has played a more and more significant role in the mechanical industry. The hydraulicbrake is a braking mechanism that applies different kinds of brake fluid totransfer the pressure force from controlling mechanism to the brakingmechanism. An electric actuator is a suitable choice to be a controllingmechanism to control the hydraulic brake system. The electric actuator is a componentof a machine that is responsible for moving and controlling a mechanism orsystem. A control

1. 研究目的与意义、国内外研究现状（文献综述）本课题的意义氧化应激不仅降低猪体的抗氧化能力免疫力和抗病力等, 导致猪生产性能的下降, 母猪繁殖过程是消耗体内大量的储备能量,为了补充能量储备,机体会增加新陈代谢率,与此同时体内会产生很多ROS等活性自由基，使得体内的氧化应激变得更强烈,带来严重的氧化损伤。了解繁殖母猪机体氧化应激水平较高的阶段，可以提前做好预防准备，通过添加食源性抗氧化剂或者抗氧化药物来降低因氧化应激造成繁殖母猪繁殖力下降的几率，使繁殖母猪的经济效益最大化。国内外研究概况母猪在饲养过程中面临着各种环境因素和管理相关的应激，长应激能够通过干扰母猪下丘脑垂体性腺轴的功能从而影响其繁殖性能和母性行为。氧化应激本质是机体产生了大量的自由基，超过了机体自身的清除能力，如�

1. 研究目的与意义（文献综述包含参考文献）2.Literature review This chapter gives a detailed introduction of previous studies in the field with which this study is closely linked. It starts with definitions and concepts of some important terms related to vocabulary knowledge. After that, previous researches on vocabulary and reading comprehension are introduced. At the end of this part, the research gap is discussed. 2.1 Definitions Many people define vocabulary in many ways, it is generally accepted that knowing a word is not limited to its dictionary definition or what it looks or sounds like. From a theoretical perspective vocabulary knowledge is a multidimensional and multi-faceted construct (Read, 2000). Three dimensions within the construct are accepted by and large,which can be defined as: vocabulary breadth (or vocabulary size), vocabulary depth and vocabulary fluency (Daller et al., 2007; Milton, 2013). According to Saeed Mehrpour and Mohammad Rahimi(2010)

1. 研究目的与意义（文献综述） Rail corrugation is a wave type wear of therail surface with a wide variety of wavelengths. Corrugation shows as an undulation of the rail surfacewith typical wavelengths between 25 and 80mm. Rail corrugation is one of themost serious and expensive problems experienced by transit systems, railcorrugation is a frequently occurring rail wear pattern that arises mostly incurves, the corrugation phenomena is considered forvehicles with low axle load, running at low speed in curves with small radius. Rail corrugation is caused everywhere due tothe combination of various factors, rail corrugation could be caused by someresonances as: The torsionalvibration of the wheel-set in curve. Excessively largecreepage between wheel and rail, which could be caused by insufficiency ofrolling radius difference between high-rail side wheels or caused by large ofattack between rail and wheel. Oscillation of wheelload, whi

1. 研究目的与意义（文献综述包含参考文献）Nowadays improving students` oral communication skills has been the primary task in Chinas college English teaching. In this study the oral accuracy among EFL learners at different working memory levels and planning conditions will be analyzed. And in this chapter, literature is reviewed in two major parts with four sub-sections in each, first on the theoretical foundation based on which this research is conducted, second on empirical studies, both involving three variants in the present study, i.e., oral production (or oral accuracy), working memory, and planning. In addition, before the end of this chapter, the author conducted a brief discussion about the limitations in previous studies.2.1 Theoretical issues2.1.1 Levelts Model of Oral ProductionBasically all studies concerning oral production or the notion of planning draw on the model of speech production proposed by Levelt (1989) as a reference. According to this model,

1. 研究目的与意义（文献综述包含参考文献）Proposal The Effects of Vocabulary and Grammatical Knowledge on the Inference of Word Meanings 1.Introduction The present study is aimed at exploring the effects of vocabulary knowledge and grammatical knowledge on EFL learners#8217; word inference. This chapter presents the concise background of the current study, aims of the study, and the organization of the study. 1.1 Background of the study Vocabulary plays an important part in L2 acquisition and is closely related to language understanding and reading performance. Vocabulary is taken as an essential part both in teaching and learning. Since 1970s, vocabulary acquisition has attracted many scholars#8217; attention. Numerous theoretical and empirical studies had been done to identify teaching methods of vocabulary acquisition. (Knight, 1994; Keating, 2008; Wu Xudong, 2010; Eckerth Tavakoli, 2012; Yue Yinglai, et al.; 2012).Researchers conducted extensive studies on t