确保数控快走丝电火花线切割加工质量的方法

数控快走丝电火花线切割加工是一种应用较广泛的特种加工,本文详细阐述了确保该特种加工质量的几种方法。     

高速走丝电火花线切割机床断丝原因与解决方法

电火花线切割加工技术能胜任难加工材料和精密复杂零件的加工,因而在机械电子、航空航天、兵器工业、工艺装备、医疗器械以及仪器仪表等行业新产品的研发过程中发挥着关键作用,尤其在模具制造领域占有极其重要的地位.高速走丝电火花线切割机床在加工中经常会发生断丝现象,断丝后会因穿丝而降低加工效率,不仅耽误时间,而且会在工件上产生断丝痕迹,影响加工质量,严重的会造成工件报废.本文从不同角度分析了断丝的原因,提出了解决方法,这些方法能切实有效地减少断丝的发生.     

微细加工及其关键技术研究

微细加工技术是随着微机械的发展而出现的全新的现代制造技术，它能在微小的尺度范围内实现机械的加工和装配。本文介绍了微细加工及其关键技术，并在深入研究的基础上，提出和试验了自己的加工方案，在特种零件的加工中较好地解决了其工艺及加工技术问题。最后，提出了今后有待进一步研究的关键问题。     

线切割在模具加工中的应用

加工的型腔。半预先加工穿丝孔,凹模穿丝空的切割进行摘要：线切割加工的特点,利用线切割进行典型凸模、凹模的分别加工和配做法,加工凹模型腔时穿丝孔的加工,新型的锥度加工及慢走丝的应用。     

线切割钼丝断丝分析

在线切割实习中,学生经常会在加工制件时,出现金属丝的断丝,但很多情况下,找不到金属丝断丝的原因,造成多次相同原因的断丝,使制件加工进度延缓,精度大幅度下降,本文以钼丝为例,对线切割实习加工中金属丝常见的断丝情况进行了分析。     

高速加工工艺与数控编程研究

本文对高速加工中刀具选择、加工工艺、工艺参数和数控编程均做了详细的论述，并对高速加工提出了较为完整、可行的加工思路。     

数控加工中的工艺分析

用数控机床加工零件比用普通机床加工零件更重视加工之前的工艺分析。本就数控机床加工零件时，所应考虑的工装的设计要求，对刀点的选择，加工路线的确定，以及刀具及切削用量的选用等问题加以分析。     

细长轴的车削加工

细长轴是轴类零件中比较难以加工的工件。采用反向走刀车削，尾座上改用弹性顶尖，中心架与过渡套筒配合使用，再配以合理的刀具几何参数等都是提高细长轴加工质量和加工效率的有效措施。     

数控线切割机电极丝张力对加工质量的影响分析

数控线切割加工系统的加工质量、效率与系统电极丝张力的大小和张紧方式密切相关。本文在分析机械式张紧装置效果及工作原理的基础上,提出了一种基于双贮丝筒的恒张力控制系统的设计框架,初步实现了张力的闭环控制,对提高数控线切割机床的加工质量具有一定的指导意义。     

数控加工中刀具的选择

刀具在数控加工中占有重要地位，数控加工者首先要了解数控加工常用的刀具种类及特点，其次要知道根据不同的数控机床、待加工零件的形状、待加工零件硬度和切削用量等来选择不同的刀具。     

论培养和提高师范生写作思维能力的环节

本文对如何培养和提高师专中文专业生写作思维能力的问题进行了探讨,主张在写作教学中教师必须把握好四个环节：一是明确思维特点,讲授思维方法;二是抓住写作理论课堂,引导学生走上科学思维轨道;三是加大文章赏析力度,锻炼科学思维能力;四是抓好习作实践,提高学生写作思维能力。     

英语否定转移的表达方式及其汉译

否定转移是指位置上与一个词或短语放在一起的否定词,有时在意义上或逻辑上可转移到去否定另一个词或短语。通过总结英语否定转移的四种表达方式,即从一般否定转移到特指否定;从特指否定转移到一般否定;从一种特指否定转移到另一种特指否定;从否定主句谓语动词转移到否定从句谓语动词,来探讨其在汉语中的翻译,以期进一步提高翻译的准确性。     

A Case Study of Preschool Children’s Musical Interests at Home and at School

In the interaction between the child and the adult, interest can be a significant motivational initiator of activities. Systematic monitoring and development of the interest in music activities enables the teachers to influence the preschool children in forming a positive attitude towards the art of music. The research involving preschool teachers, children at the age of five to six and their parents, was conducted in order to determine the interest of preschool teachers and children in music activities. We found that the teachers showed greatest interest in singing songs, playing instruments and listening to music. The children’s favourite activities in kindergarten were movement to music (dancing), singing songs and playing on instruments, namely activities where they could take active part in the educational process. The parents reported that at home the children preferred most to listen to music, to sing songs and move to the sounds of music, and less to play on instruments and to be creative in music. The development of the children’s interest in music depends on the teachers’ expression of interest in music activities, on the choice of music activities and music contents and on the experience in the music environment of the family.     

The Scientist as School Teacher

Many scientists, driven by the teaching impulse, idealism, or the wish to see science thrive in the United States, take up one or another form of school teaching or participate in programs designed to enhance science teachers' knowledge of science and science teaching skills. Funding is available, from governmental and private sources, to support innovative programs designed to increase the supply of well-trained science teachers. The provision of new funds to support graduate programs in fundamental science that provide a separate track for graduate students who choose a career in teaching, in preference to a career in the laboratory, is a particularly promising development. It is essential that such programs include proper training in pedagogy. Above all, the Nation must recognize the need to provide proper long-term salary support for science teachers in the public schools countrywide, if any of the programs to improve teaching is to succeed.     

What successful black South African students consider as factors of their success

Black South African students have a poor success rate in school leaving mathematics examinations. Attempts have been made to shift teachers' practices from teacher-centredness to learner-centredness, in Black schools, in order to improve the situation. So far, the attempts failed to yield the desired results. This paper reports on the findings of a study that aimed at learning from students and teachers in Black schools, as to what classroom practices lead to success in school mathematics, in their impoverished context.This revised version was published online in October 2005 with corrections to the Cover Date.     

从新托福考试看英语听力训练

即将于2D04年正式开始的新托福考试目前已经通过美国KIS中心设计的“LanguEdge”(锋利英语)教程中的考题模型呈现出来，新托福的宗旨基本上是对听、说、读、写综合应用能力的真正考查。新托福试题的内容和题型变得更加贴近北美大学学习和生活的实用需求。相对于旧托福而言，新托福明显增加了我国众多考生明显薄弱的听、说两个环节。新托福不仅将会给中国的英语教学带来一个新的冲击，促进我国英语教学的改革，而且还会给我们的听力教学带来不少有益的启示。     

Leaping Out of Our Skins: Postmodern considerations in use of an electronic whiteboard to foster critical engagement in early literacy lessons

Postmodern theory is used to consider literacy instruction with and without an electronic whiteboard to investigate what it means to move beyond using technology to replicate older models of classroom structure that may be historically situated but that also limit or at least, do not support engagement in ways that may be possible through use of new technologies. Using postmodern theory in this regard is a way in which to consider again the thoughts and practices that tend to construct identities and ideologies in ways that work against true engagement in literacy tasks, lead to subjection and demonstration of acquiescence in place of engagement that leads to participation and critical engagement. Critical engagement as opposed to gaining and maintaining student attention to task are considered in this paper. Thinking about use of the electronic whiteboard from a postmodern perspective cautions us about careful use of this technology to avoid sending messages to students about them and their role in literacy development, the classroom, and in society.     

论辛亥精神

辛亥精神是指在辛亥革命过程中,以孙中山为代表的革命派为了推翻满清统治、建立资产阶级共和国而彰显的一种敢为天下先的不怕牺牲、勇往直前、追求民主与进步的优秀品质。它开启了20世纪中国人民精神的新风貌,是激励中国人民救国救民和推动中国社会进步的强大动力,这种精神对我们今天仍有积极的意义。     

Japan’s colonial policies – from national assimilation to the Kominka Movement: a comparative study of primary education in Taiwan and Korea (1937–1945)

The eight-year-long period from Japan’s initiation of the Second Sino-Japanese War in 1937 to its unconditional surrender in 1945 forced Japan to invest its national economy and industrial and scientific technologies in the war. In addition, in the name of the Greater East Asia Co-Prosperity Sphere, Japan initiated its assimilation and Kominka (Japanisation) policies (皇民化政策) in the colonies Korea and Taiwan. Japan used education as a tool to expand its influence over members of society, and attempted the frequent use of Japanese and Kominka (皇民化) in daily life to penetrate the awareness of people in the colonies. Japan also started to enforce various assimilation policies. A comparison of the implementation of Kominka policies (皇民化政策) in Taiwan and Korea shows that, in terms of school admission rates and frequency of use of Japanese, the proportion of school admission rates for frequent speakers of Japanese to primary education in Taiwan are significantly higher than those in Korea. Moreover, in terms of primary education, national schools were implemented in both Taiwan and Korea according to the “National School Order” promulgated in 1941. Japan made use of the term “education equality” to win people over. In fact, it aimed to strengthen the concept of Kominka (皇民化), the education of militarism, and to force the Taiwanese and Koreans to become “imperial citizens” loyal to the Emperor. Japan’s ultimate objective was to create an environment that met military needs for civilian and military resources.     

地方高师院校学科建设刍议

我国高等教育改革与发展的新形势要求地方高师院校重视和加快学科建设。地方高师院校学科建设的核心是搞好学科布局和凝炼学科方向;关键是抓好学科队伍建设;必须抓好学科基地建设;必须遵循有所为、有所不为的原则,贯彻分类指导、分层次建设、滚动式发展的方针;必须健全和完善学科建设的组织机构,探索并建立有效的学科建设运行机制。