How to Tackle the Problems in Large Classes

本文通过对大班英语教学环境的分析,介绍了三种大班英语授课的方法及具体措施。这些方法是多年英语教学经验的总结,主要通过师生互动、创设语言学习环境和教学管理相结合的模式,提高大班英语授课的教学效果。

Appropriate Combination of Crossover Operator and Mutation Operator in Genetic Algorithms for the Travelling Salesman Problem

Genetic algorithms(GAs)are very good metaheuristic algorithms that are suitable for solving NP-hard combinatorial optimization problems.AsimpleGAbeginswith a set of solutions represented by a population of chromosomes and then uses the idea of survival of the fittest in the selection process to select some fitter chromosomes.It uses a crossover operator to create better offspring chromosomes and thus,converges the population.Also,it uses a mutation operator to explore the unexplored areas by the crossover operator,and thus,diversifies the GA search space.A combination of crossover and mutation operators makes the GA search strong enough to reach the optimal solution.However,appropriate selection and combination of crossover operator and mutation operator can lead to a very good GA for solving an optimization problem.In this present paper,we aim to study the benchmark traveling salesman problem(TSP).We developed several genetic algorithms using seven crossover operators and six mutation operators for the TSP and then compared them to some benchmark TSPLIB instances.The experimental studies show the effectiveness of the combination of a comprehensive sequential constructive crossover operator and insertion mutation operator for the problem.The GA using the comprehensive sequential constructive crossover with insertion mutation could find average solutions whose average percentage of excesses from the best-known solutions are between 0.22 and 14.94 for our experimented problem instances.

Problems and Possible Solutions in Reading Comprehension Testing

The paper dealswith the problemsin reading testing papers. The author proposessome possible solutions, such ascov- ering more cognitive skillsbeing tested, increasing more text types, adding some other testing item types.

Second Language Lecture Comprehension: Student's Perception, Problems and Strategies

The ability to comprehend academic lecture is an important part of the necessary proficiency of tertiary level students for whom English is a second or foreign language. The purpose of this research is to investigate the lecture-perceived experience of one non-nativespeaking learner who attending her English medium lecture course in the first semester in New Zealand. It describes how the learner perceives the lecturing experience, the problems she encounters and the strategies she use to overcome these problems.

Analysis on the Influencing Factors and Comprehensive Management of Environmental Problems in Dongping Lake

[Objective]We aimed to study the influencing factors and comprehensive management of environmental problems in Dongping Lake.[Method]Based on field investigation and historical data,environmental problems of Dongping Lake and their influencing factors were analyzed,and seven measures about comprehensive management of environmental issues and ecological protection of Dongping Lake were put forward.[Result]During recent years,the content of total nitrogen and total phosphorus in Dongping Lake showed a decreasing trend,but the water was still in the eutrophic state.The environmental problems of Dongping Lake,like flood,drought and pollution,are closely linked to natural and man-made factors,such as regional seasonal precipitation,industrial and agricultural pollution,etc.In order to control the environmental problems of Dongping Lake,we should strengthen the construction and management of wetland nature reserves,develop ecological agriculture,establish an integral system for environmental monitoring and information management,reinforce propaganda and education to improve residents’ environmental consciousness,etc.[Conclusion]The research could provide scientific references for the comprehensive management of environmental problems in Dongping Lake and its basin.

Comprehensible Technique in Solving Consecutive Number Problems in Algebra

This research paper evaluated and investigated the effectiveness of the comprehensible technique (CT) introduced by the researcher as an alternative solution to Algebra’s linear equations in solving consecutive number problems. The CT is a proposed easy and efficient way of solving number problems which aimed to help the learners reduce their difficulties in using variables since the technique only uses basic arithmetic and mental Mathematics. Evaluation research was utilized in this study where 20 people, from various ages and professions, were chosen purposively as respondents of the study. The study found out that CT was very effective for the respondents especially in unlocking difficulties in solving consecutive number problems. Moreover, according to them, the CT is easy to use, it is engaging and enjoyable, direct and simple and can be utilized as shortcut way of solving consecutive number problems when competing in Math quiz bees or taking board examinations where time is of the essence.

Tackling Key Technological Problems and Advancing 5G Technology Application in Railway

The paper summarizes the development of mobile communication of domestic and foreign railways,and proposes the priorities for tackling key technological problems of railway 5G private network according to the technical routes of railway next-generation mobile communication determined by China State Railway Group Co.,Ltd.From the aspects of work objectives,principles,technical routes and innovative working methods,the paper elaborates the ideas of railway 5G scientific and technological research,puts forward the contents and plans of scientific and technological research on railway 5G private network,systematically organizes the achievements in the scientific and technological research stage of railway 5G private network,and sets forth the key contents of next-step scientific and technological research.

On Strategies in English Listening at Junior Middle Schools in Rural Areas

It is so disappointed that at present, the students' listening ability is extremely poor, especially that of the middle school students in rural area. There are plenty of factors that cause this problem, among which there are three major reasons. They are the insufficient equipment in the school, the lacking of interest of the students and the difficulty in the listening study.

Physical principle of wind erosion on sandy land surface in southern Beijing

The endangerment of aeolian sand is one of the most serious eco-environmental problems facing the southern suburb of Beijing. To control wind erosion is thus a matter of great urgency. This paper chooses typical land-use types, i.e., cultivated land, wild grassland, drifting sandy land, etc. based on the fixed experimental observation and quantitative analysis, to conduct studies on the principles and characteristics of aeolian activities and measures controlling wind erosion in Daxing District of Beijing, The results show that： the near ground wind velocity yielded the logarithmic distribution with height; there are significant differences among different ground cover roughness; there are significant differences in the corresponding friction velocities caused by different properties of the underlying surface; there are differences in the threshold wind velocities speed in different land .use types; and there are minus exponential relations between the sediment discharge percentage and the height at a range of 0-20 cm air flow layer, Different land use types result in various degrees of coarse component. There is a significant exponential relation between sediment transport concentration and wind velocity.

PDCA循环在公立医院综合查房问题整改中的应用与成效

东莞市滨海湾中心医院将PDCA循环应用于综合查房问题整改,针对综合查房问题整改存在的缺陷,通过“分析问题,制定计划”“实施计划,解决问题”“持续检查,跟踪问效”“提炼标准,总结经验”四个阶段的持续循环改进,打通了跨组织、跨层级的业务协同壁垒,提高了领导决策力和部门执行力。应用后,查房问题的整改率显著提高,临床医技科室对查房问题整改平均满意度明显改善,查房工作取得较好实效;同时进一步健全了医院管理制度、规范了工作流程。做到以问题为导向,切实解决好影响人民群众的就医体验以及困扰医院持续发展的重点与难点问题,从根本上提高了服务品质,赋能医院高质量发展。

Comprehensive form of solution for Lamb's dynamic problem expressed by Green's functions

By the analysis for the vectors of a wave field in the cylindrical coordinate and Sommerfeld＇s identity as well as Green＇s functions of Stokes＇ solution pertaining the conventional elastic dynamic equation, the results of Green＇s function in an infinite space of an axisymmetric coordinate are shown in this paper. After employing a supplementary influence field and the boundary conditions in the free surface of a senti-space, the authors obtain the solutions of Green＇s function for Lamb＇s dynamic problem. Besides, the vertical displacement uzz and the radial displacement urz can match Lamb＇s previous results, and the solutions of the linear expansion source u^r and the linear torsional source uee are also given in the paper. The authors reveal that Green＇s function of Stokes＇ solution in the semi-space is a comprehensive form of solution expressing the dynamic Lamb＇s problem for various situations. It may benefit the investigation of deepening and development of Lamb＇s problems and solution for pertinent dynamic problems conveniently.

A retrospective view on the history of natural sciences in XX-XXI

The presented paper is dedicated to a new ret-rospective view on the history of natural sci-ences in XX-XXI cc, partially including the sci-ence philosophy (mainly, the problems of the scientific realism, i.e. the correspondence of science to reality) and also a novel scheme for different classes of sciences with different ob-jects and paradigms. There are analyzed the chosen “great” and “grand” problems of phys-ics (including the comprehension of quantum mechanics, with a recently elaborated new chapter, connected with time as a quantum obs- ervable and time analysis of quantum processes) and also of natural sciences as a whole. The particular attention is paid to the interpretation questions and slightly to the aspects, inevitably connected with the world- views of the res- earchers (which do often constitute a part of the interpretation questions).

Build the First-class Plateau Railway in the World

The construction engineering of Qinghai-Tibet railway is formidable but magnificent with very complicated geological conditions, facing “three difficult problems" of permafrost, severe coldness & oxygen deficiency and fragile ecology. All of the working staff stick to human foremost principle, upgrade construction concept, realize the management innovation, implement the legal person responsibility system for construction project, form the management system featuring in the integration of quality-environment-occupational health & safety, optimize project organization & coordination system and establish the complete & rigorous construction target system. Tackle the difficulty of permafrost relying on science and technology and the finished roadbed, bridges and tunnels are in stable condition. Carry out the basic national policies and protect geological environment, being the leading position in the construction of important and key construction projects and of demonstration significance. Insist on human foremost principle and guarantee the occupational health, creating the altitude medical miracle of “zero death of high-altitude disease, zero occurring of SARS and zero spread of plague". The construction also advances and implements “three specific requirements", that is, the train passes the plateau in fast speed, high-reliable and less maintenance of operation equipment and minimum management staff of the line.

基于PBL模式的EDA技术实验教学改革

针对EDA技术基础实验与综合设计缺少联系,学生在有限实验学时内只能完成一些简单数字系统等问题,引入问题驱动教学法(Problem-Based Learning,PBL)对EDA技术实验进行深化改革。以综合设计导入作为EDA实验教学起点,以综合设计作为核心问题反向设计基础实验的教学内容,以学生作为主体围绕问题寻求解决方案,实践效果表明,显著提升了学生学习的主动性,相同学时可以设计出更加复杂的系统,提高学生解决复杂工程问题的能力。

Mathematica软件在高等数学教学中的运用

Mathematica软件具有强大的数值计算、符号计算、绘图、程序设计等功能,高等数学教学中引入Mathematica软件作为教学的辅助工具,可解决学生数学运算问题,函数的图形绘制问题等,提高学生的数学分析能力和解决综合应用问题的能力.

Mathematica软件在高等数学教学中的应用

Mathematica软件是一套专门进行数学计算的软件，在高等数学中引入Mathematica软件进行辅助教学，有利于增强教学的直观性．激发学生学习兴趣．提高学生解决数学综合问题的能力。

基于ANP的生产型二级供应链需求点综合评价指标体系研究

为了明确生产型二级供应链上需求点的定位,制定合时宜的发展战略,需要对其进行多指标的综合评价。文中首先讨论了传统指标评价方法的不足以及ANP方法的相关理论和应用,然后通过分析生产型供应链上需求点的指标体系,构建了基于ANP的需求点多指标综合评价模型,最后采用了三个需求点进行算例分析,从计算权重角度比较了AHP和ANP的差别,说明了ANP的效果。

烧结矿喷洒CaCl2降低烧结矿低温还原粉化率

为提高铁产量，解决铁产量不足制约炼钢生产问题，莱钢进行了为期3个半月的提高铁产量攻关，从生产组织、技术管理、原料供应等方面协调解决炼铁生产中存在的问题。经过攻关，在1^#750m。高炉大修期间，日产铁量从1^#750m。高炉停炉前的2．44万t提高到2．47万t。