1. 研究目的与意义（文献综述） 1.1 Background, purpose and meaning. The safety of the car has always been avery significant part of the car design process. In the northern region ofChina, the phenomenon windshield frost fog seriously affect the driver's visionwhen driving. The formation of fog is mainly due to the lower externaltemperature, the passenger breathing the steam generated in the windshieldcondensation to form a layer of water film -. If the external temperature is long below zero, thetemperature of the inner surface of the windshield is also lower than zero, sothat the water molecules on the inner surface of the windshield are cured toform a f. Another reason for frosting is the heat generated bythe passengers make the snow accumulated on the outer surface of the windshieldquickly melts, and because the external temperature is very low, the meltedsnow is quickly frozen on the windshield. It is well known that adequatevisibility through the vehicle windshield ov

1. 研究目的与意义（文献综述） Research purpose: In the field of second language learning,quantity and quality of vocabulary are essential for language learners. Therefore, various learning methods are always employed and practiced by language learners in the process of mastering new words. The study of language learning strategies has been an area of immense interest for quite some time. From my point of view,effective and efficient learning strategies enable English learners to get twice the result with half the effort. As for my research, I will collect data from four-gradestudentsthrough a questionnaire and a semi-structured interview, aiming to analyze the relevance between the learning strategies used by English learners and the size of their vocabulary. Specifically, my purpose is to answer these questions: 1) What learning strategies do students witha larger vocabulary size use? 2)Whatisthe difference in the use of vocabulary learning strategies between the lower-g

1. 研究目的与意义 针对多元线性回归估计中可能出现的偏差，探索适当方法减低估计偏差，从而提高估计模型的拟合优度，达到提高统计决策的可行度并降低风险的目的。 2. 研究内容和预期目标 由于多元线性回归的拟合图像受极端值的影响非常大，故在进行多元线性拟合时，要使用差分法、逐步回归分析、主成份分析、偏最小二乘回归、岭回归、增加样本容量等方法消除多重共线性残差图、BP检验、White检验法检测异方差性用数据处理（取对数）、Robust稳健标准误回归和FGLS法法消除异方差。 3. 国内外研究现状 异方差性的检验方法 1.图示检验法:相关图分析;残差图分析。 2.Goldfeld - Quandt 检验法。 3.怀特(white) 检验。 4.帕克检验( Park test ) 和格里奇检验( Glejser test)。 对于多重共线性的检验和消除方法 1、简单相关系数矩阵法（辅助手段） 此

1. 研究目的与意义（文献综述） TD-SCDMA was proposed in 1998 on behalf of China by CATT (Chinese Academy of Telecommunication Technology), and approved by ITU(International Telecommunications Union) as one of the international CDMA standards for 3G mobile communicaitons in May 2000. TD-SCDMA adopts a series of techniques, such as TDD, synchronous CDMA, smart antenna, joint detection, software radio, baton handover, dynamical channel allocation, and so on. The industries have always battled fordominance between two or more technologies, often the well-established firms ("What Is TD-SCDMA | 3G TD-SCDMA |Radio-Electronics.Com"). In this paper, I am going to focus on thedynamic channel technology of TD-SCDMA (Time Division-Synchronous Code DivisionMultiple Access). It is named as the standard made by China, however, it holdsonly the 7% core patent technology and the rest is with other countries. TD-SCDMAis adopted by the ITU (International Telecommunications Union) as a 3Gstand

1. 研究目的与意义、国内外研究现状（文献综述）肉品加工品质是影响现代肉制品加工发展的重要因素，如何最大可能地发挥肌肉蛋白自身的功能特性，提高产品品质是肉制品加工业亟待解决的关键问题。肌肉中蛋白质的种类很多,其中肌球蛋白是动物肌肉中最重要的一种蛋白质,约占肌肉蛋白质的30%,肉类食品良好品质的形成主要来源于肌球蛋白形成的热诱导凝胶。虽然肌球蛋白不是添加食盐和多聚磷酸盐后从肉中唯一被提取的蛋白,但却是唯一经纯化后加热能形成凝胶的蛋白质。因此肌球蛋白功能特性特别是凝胶特性的研究对于提高肉品品质,改进生产工艺具有重要的意义。2. 研究的基本内容和问题研究影响肌球蛋白功能特性因素。主要是组氨酸和赖氨酸对肌球蛋白的浊度、溶解性及热诱导凝胶等功能特性的影响。3. 研究的方法与方案一、肌球蛋白�

1. 研究目的与意义（文献综述包含参考文献）1.Introduction1.1 Research backgroundStudying oral fluency has become a burgeoning area of research within second Language Acquisition (SLA) and Language Testing (LT). Speech fluency, as we discuss it here, refers to what Segalowitz (2010) calls utterance fluency, that is, the ability to produce meaningful strings of linguistic symbols in a largely uninterrupted fashion (Gtz, 2013). Speaking a second language (L2) is a challenging task for many people. Even if second language learners have learned a second language for many years, they at times find themselves speak a second language not so fluently. In previous studies examining oral fluency, fluency measures typically represent the three main dimensions of fluency: breakdown (e.g., different aspects of pausing), speed (e.g., speech rate) and repair (e.g., repetitions and corrections) (Gan, 2013; Peltonen, 2017). In L2 oral fluency research, pause is a necessary index employe

全文总字数：13233字1. 研究目的与意义（文献综述） 1.1 Purpose and meaning of the study With the development ofthe economy, the number of vehicles is constantly increasing, and the world ’soil resources are reducing. New energy vehicles, which are compared withtraditional internal combustion engines, have become the future direction ofthe automotive industry. On October 26, 2016, the Chinese Society of AutomotiveEngineers released the Technology Roadmap for Energy-Saving and New EnergyVehicles. Roadmap planning: In 2020, sales of pure electric vehicles andplug-in hybrid vehicles will account for 7% -10% of total vehicle sales; 2025,15% -20%; and 2030, 40% -50 %[1]. Battery electric vehicles(BEV) are new energy vehicles that are powered entirely by rechargeablebatteries, with electric motors as the drive system. Due to the use of electricenergy, no exhaust gas is emitted during the driving process of the pureelectric vehicle, which does not pollute the environment a

1. 研究目的与意义（文献综述包含参考文献）Literature review In the field of Second Language Acquisition (SLA) research, language competence can be studied from different aspects. Many scholars do research in the use of chunks and fluency of output, especially in oral English. In this chapter, the author will discuss four sections. Section one states the two key terms, chunk and fluency. Section two study the theoretical issues and section three displays empirical studies. Finally, the author addresses the research gap of this study. 2.1 Key terms 2.1.1 Chunk The conception of chunking was first put forward by American psychologists Miller and Selfridge in 1950s to explain the process of unit information into chunks. From 1970s, the noun ”chunk” has been introduced into linguistics teaching filed. It refers to block structure which is between grammar and vocabulary, fixed or unfixed, and macular. Many scholars at home or from aboard do many researches o

1. 研究目的与意义（文献综述包含参考文献） 毕 业 设 计（论 文）开 题 报 告 1． 结合毕业设计（论文）课题情况，根据所查阅的文献资料，每人撰写2000字左右的文献综述： 1. Introduction Listening comprehension has played a significant role in second language acquisition because it is essential in communication. Meanwhile, our study and living environments are becoming more and more internationalized. We may encounter many foreigners with different accents in our work. Meanwhile, we may listen to materials with different difficulty levels. As a result, we want to explore the relations between accents and difficulty levels and English listening comprehension. In this study, we take American and British accents for example, which appear in our life most frequently. The aim of our research is to make our listening comprehension better. 1.1 Need for the study In the process of listening research, we have f

1. 研究目的与意义（文献综述） This paper focuses on the design, selection and layout of power system for the 6-axis all-wheel drive EVs. There are four aspects, the first is a choice of variety of battery types , and it needs to meet the requirement that the 2 tons’ car at least could drive 50km mileage; selection of drive motor, for example, DC or AC motor which with sufficient power density and torque density, and ultimately meet the maximum car speed 40km/h with the basic load and climbing requirements; at last, selection for the wheel brake system to ensure maximum utilization of energy, increase battery life and mileage. When it comes into the 21st century, with the endless stream of energy problems and the gradually appear of drawbacks of traditional vehicles, domestic and foreign governments grow to support new energy vehicles more and more. In 2010,the government began to provide economic subsidies and concessions for electric vehicle purchases. In the year 2012