1. 研究目的与意义（文献综述包含参考文献）1. Introduction 1.1 Research Background Primary English teaching is at the elementary education stage, that is to say, the English teaching level of primary school English teachers directly affects the proficiency and development of primary school students in their future English study. Therefore, it is imperative to improve teaching standard. However, some primary English class teaching is still very boring due to the failure of arousing primary students#8217; interest of studying English. ”Primary English curriculum standards” points out that interest is the key to learning language. Stimulating primary students#8217; interest in learning English is an important task for English Teaching in primary schools. In the new era of time, primary school English teachers should actively adopt innovative English teaching models, such as Game Teaching Method. Through numerous teaching experiments, the game teach

1. 研究目的与意义 帕金森病（PD）是一种中老年常见的以中脑黑质多巴胺（DA）神经元缺损为主要病理基础的慢性进展性神经退行性疾病，路易小体（Lewy body）是PD的病理特征之一，α-突触核蛋白（α-synuclein）是其主要组成成分，α-synuclein的折叠异常和降解减少可能是其在细胞内聚集，导致DA神经元损伤的主要机制之一。自噬是真核细胞特有的生命现象，在一些生理和病理因素的诱导下，由一种前自噬结构PAS（pre-autophagosomal structure）形成双层膜结构的自噬泡，并逐渐延长、包裹待降解的蛋白质、细胞器，形成自噬体；然后自噬体的外膜和溶酶体膜融合，形成自噬溶酶体，内膜和包裹的物质进入溶酶体腔，被蛋白水解酶（cathepsins）降解，降解后的成分可被细胞循环利用，从而维持了细胞的自身稳定。野生型和突变型α-synuclein均可通过自噬途径进行降�

1. 研究目的与意义 背景： 传统的混凝土虽然已有近200年的历史，也经历了几次大的飞跃，但今天却面临着前所未有的严峻挑战。随着现代科学技术和生产的发展，各种超长、超高、超大型混凝土构筑物，以及在严酷环境下使用的重大混凝土结构，如高层建筑、跨海大桥、海底隧道、海上采油平台、核反应堆、有毒有害废物处置工程等的建造需要在不断增加。这些混凝土工程施工难度大，使用环境恶劣、维修困难，因此要求混凝土不但施工性能要好，尽量在浇筑时不产生缺陷，更要耐久性好，使用寿命长。 进入20世纪70年代以来，不少工业发达国家正面临一些钢筋混凝土结构，特别是早年修建的桥梁等基础设施老化问题，需要投入巨资进行维修或更新。1987年美国国家材料咨询局的一份政府报告指出：在美国当时的57．5万座桥梁中，大约有25．3万座

1. 研究目的与意义（文献综述） Withthe development of social economy and the increasing number of automobile ,traveling becomes convenient and fast, but traffic congestion and trafficaccidents have been a major problem in today's society. In order to solve theseproblems, with the use of computer control technology and automatic controltechnology in automobiles, we get a driverless car, which means a majorrevolution in the automotive industry. Driverless cars, also known asself-driving cars or wheeled mobile robots, which could perceive thesurroundings with on-board sensors without driver, and Implement the drivingprocess relying on intelligent pilot according to the obtained information. [1] Atthis stage, most of the countries are researching driverless cars to adapt tothe trend of the car’s development. Since2007, Carnegie Mellon University, Stanford University research institutes and Googlehave begun testing driverless cars on urban roads. In 2012, the Nevada Mo

全文总字数：24746字1. 研究目的与意义（文献综述） Withthe development of social economy and the increasing number of automobile ,traveling becomes convenient and fast, but traffic congestion and trafficaccidents have been a major problem in today's society. In order to solve theseproblems, with the use of computer control technology and automatic controltechnology in automobiles, we get a driverless car, which means a majorrevolution in the automotive industry. Driverless cars, also known asself-driving cars or wheeled mobile robots, which could perceive thesurroundings with on-board sensors without driver, and Implement the drivingprocess relying on intelligent pilot according to the obtained information. [1] Atthis stage, most of the countries are researching driverless cars to adapt tothe trend of the car’s development. Since2007, Carnegie Mellon University, Stanford University research institutes and Googlehave begun testing driverless cars on urban roa

1. 研究目的与意义（文献综述包含参考文献）1. Introduction1.1 Research backgroundLanguage as one of the most important tools shapes the development of human society in many fields, like education and daily communication. The language we first procure since we were born is called the first language (L1). Apart from L1, other kinds of language we learn afterwards can be called the second language (L2). In the past decades, researchers have put forward numerous assumptions and well-established theoretical models of L1, whereas the research of L2 still has a long way to go. English, the most widespread-use language, is the L2 for majority of people in many parts of the world, especially in China. College students in China are asked to pass College English Test Band 4 and Band 6 (CET4 and CET6). And students from English major are required to pass Test for English Majors-Band 4 and Band8 (TEM4 and TEM8). From these text papers, we can discover that the scores of reading com

全文总字数：1920字1. 研究目的与意义及国内外研究现状 本题的主要目地是结合“数据结构”课程，采用Django框架进行在线考试系统的设计和研发，旨在提高当前考试的效率和节省资源，提高学生们对于考试内容的实际掌握能力和合理的分析学生知识掌握的实际情况。 通过对本系统的设计，不仅方便对学生的成绩进行考核，而且节省了教师进行批改的时间，减少人力和其他资源的消耗。通过在线考试这种方式，有利于考核学生运用实际编程环境编写与调试程序的能力，也解放了学生发散性思维的应用。 国内外研究现状 自上世纪九十年代开始，在线考试就开始出现，并逐渐发展。世界上最大的教育考试服务机构——美国教育考试服务中心ETS(Educational Testing Service)从1993年开始在研究生入学考试中采用自适应考试模式，同时逐步减少纸卷考试中以笔试�

1. 研究目的与意义（文献综述包含参考文献）2. Literature ReviewResearchers in the areas of applied linguistics and instructed second language acquisition have always been interested in measuring second language performance. One shortcoming of the research done so far on task performance is that it has focused mostly on the syntactic aspect of complexity, with very few studies investigating the lexical aspect of this performance area. Skehan (2009b) states that lexis has been strikingly absent in task research and that it is vital to incorporate some measures of lexis into task performance. The three dimensions of complexity, accuracy, and fluency thus need to be supplemented by measures of lexical performance. The range of measures also needs to be widened to cover this additional area. Most of the studies conducted in the area of task performance have used only lexical diversity as the measure of lexical performance. We also need to consider how different measures of

全文总字数：5396字1. 研究目的与意义（文献综述） 齿轮箱,又名变速箱，是一种基础动力传动装置，通过不同齿数的齿轮之间啮合，将马达的转速转换到执行设备需要的转速，并能改变转矩。在目前的动力传动机构中，齿轮箱的应用相当广泛，几乎可以在各种机械传动系统中见到它的存在，比如交通工具中的船舶、汽车等行业，加工机器及自动化生产设备的机械行业，甚至日常生活中的家电、钟表等。它由一组组齿轮构成，通过应用单元结构模块化设计原理，极大的减少了零部件种类，适合大规模生产，通过略微改动可以灵活选型。齿轮箱的布局设计不仅使齿轮传动的结构简化，还便于装配、更换以及检查。由于其特性，能够胜任从大动力的运输工作到小负载的精确传输，所以广泛应用在速度与扭矩的转换设备中。 随着国家新的产业结构调整政�

1. 研究目的与意义（文献综述） 目的及意义： 随着人们生活水平的提高，航空出行成为了越来越多人的首选方式。随着民用航空的快速发展，相关条例对民机安全性的要求也不断提高。飞机虽然是安全系数最高的出行工具，但一旦失事，存活率几乎为零。近年来，国内外开展了大量抗坠撞的试验和仿真研究，而坠撞分析的最终目的是为了评估飞机坠撞瞬间的动态响应，以及机身结构的破坏形式和特征。通过研究民机在不同坠撞情况下的破坏特征，可以提出相应的飞机机身强度改进方式，优化飞机机身结构设计，对保障乘员的安全具有重要的意义。 适坠性是指飞机在发生坠撞时具有的一种保护乘客安全的能力，适航条例对民用飞机的适坠性具有明确的要求。近年来，民机失事事件报道有增无减，传统机身材料已经不能满足机身合理性设计的