压力容器参数化设计方法研究

主要研究压力容器参数化设计方法,介绍了基于Auto-CAD的二次开发技术,并从法兰图纸自动绘制、支撑式支座建模、管道设计等方面对压力容器的参数化设计方案入手对压力容器参数化设计方法进行了讨论。     

桥梁球冠型橡胶支座通过鉴定

<正> 一种结构新颖、性能优良的桥梁工程用TCYB型球冠圆板式橡胶支座,由扬州橡胶总厂开发研制成功,元月4日通过了江苏省科委主持的专家科技新产品省级技术鉴定。 该产品是以橡胶与多层钢板复合硫化而成的新型桥梁支座,在圆板式橡胶支座     

一起付款方式不当案的背后

2006年7月8日,甲公司某项目部同乙公司某地区代理商刘某签订橡胶支座买卖合同两份,该两份合同均由刘某提供,加盖有乙公司的公章。合同约定：由乙公司为项目部供应橡胶支座1000套,价款共计人民币8万元,由乙公司向项目部不定期供货,每次供货时间由项目部通过传真通知乙公司,乙公司负责将合同标的物运输至项目部工地。合同价款由项目部通过银行电汇至乙公司账户,     

路桥施工企业物资询价采购初探

询价采购,是指对3家以上的供应商提供的报价进行比较,以确保价格具有竞争性的采购方式。它具有方便快捷、灵活高效的特点。被许多单位所采用。2002年我们对混凝土预应力钢绞线、桥梁橡胶支座、桥梁伸缩     

轴瓦式支座静力试验加载设计方法

某特种装置前支座为轴瓦式分体组合卡箍形式,受力情况复杂,静力试验加载设计成为技术难点.提出一种能够进行角度翻转的试验加载装置,包括角度翻转夹具、过渡平台和加载夹具.角度翻转夹具为矩形工字梁结构,可实现角度转换;过渡支撑平台为槽钢梁与钢板组合结构,负责载荷传递;加载夹具为杠杆式二力杆结构,实现拉压双向载荷施加.三部分以均...     

通风式离合器气囊通过省级鉴定

<正> 扬州橡胶总厂研制成功的通风式离合器橡胶气囊最近通过了由江苏省科委和省石化厅主持的新产品省级鉴定。 该产品是以橡胶为内外层,以帘布纤维为骨架层硫化而成的中空橡胶制品,主     

一种楔块增力式自锁液压卡爪装置的研究与应用

楔块增力式自锁液压卡爪装置是以增力楔块的斜燕尾导轨设计实现自锁为基础的装夹装置，用于高铁桥梁支座的加工，有效的解决了目前杠杆式夹紧装置所带来的问题。该装置运用斜度角小于摩擦角，无论力如何增加都不能移动的原理形成自锁，实现工件的自动夹紧。在系统断电或油缸泄压的情况下工件夹紧力仍可保持，保证加工环境安全性。     

新型柔式抽油机牵引带可靠性分析

针对新型柔式抽油机牵引带易失效问题，采用有限元分析软件ANSYS11．0的概率设计（PDS）技术，建立弯段牵引带的可靠性分析有限元模型，分析内部强力丝成均匀、对称、中间分布时牵引带的可靠度，橡胶压应力的可靠度依次减小，可靠度为99．99％、93．98％、33．78％；但强力丝拉应力的可靠度依次增大，可靠度为45．29％、54．44％、69．10％。选用牵引带时，必须综合考虑橡胶和强力丝的可靠度．为改进牵引带设计、进行可靠评定提供理论依据。     

底支座注塑模具设计及制造

分析底支座的结构工艺及塑件模具的设计要点,对模具结构、浇注系统、成型零件和抽芯机构等主要部分进行分析设计。实践证明模具塑件质量符合设计要求、结构合理、动作可靠。     

振动输送机传动机构故障分析与解决

偏心摇杆式振动输送机,在使用中噪声大、振动,摇杆上的橡胶条磨损快,橡胶缓冲器变形不均匀,两年时间内,振断4根直径36mm的连杆,磨坏两个曲柄。建立数学模型分析,是由于安装橡胶缓冲组件的连杆座与平衡体焊接角度不合适所致。通过校正曲柄连接体、丝杠连杆和曲柄偏心轴线,使问题得到解决。     

丁苯橡胶的国内外供需现状及发展前景

2005年全球丁苯橡胶的总生产能力为4737kt／a，总消费量为4011kt／a。预计到2010年总消费量将达到4823kt／a。目前，我国丁苯橡胶的总生产能力为597kt／a，2005年产量为514．2kt／a，消费量为653．2kt／a，产不足需，每年都需大量进口。预计2007年我国丁苯橡胶消费量将达到720kt，2010年消费量将达到850kt。针对目前我国丁苯橡胶生产状况及存在的问题，提出了今后的发展建议。     

国内外丁基橡胶生产现状和市场前景

目前，全球丁基橡胶的总生产能力约为892kt／a，2003年总消费量约为747kt／a。预计到2006年总消费量将超过800kt／a。目前我国丁基橡胶的总生产能力为30kt／a，2003年产量为27kt／a，消费量约为100kt／a，产不足需，每年都得大量进口。预计到2005年丁基橡胶的消费量将达到140kt／a，2010年消费量将达到210kt／a。针对目前我国丁基橡胶生产状况及存在的问题，提出了生产发展的建议。     

Secondary level engineering professional development: content, pedagogy, and challenges

The design of this study was a multiple case study conducted to examine the knowledge, pedagogical principles, and challenges involved in providing engineering-oriented professional development for teachers at the secondary school level. A set of criteria was used to identify five representative projects for analysis in the US. A variety of tools and processes were used to gather data including on-site observations, interviews, focus groups and document reviews. Results of the study indicate that engineering professional development tends to be based on work focused on curriculum development and implementation. Given the distinct design orientation of engineering, it is not surprising that the focus of engineering-oriented professional development tends to concentrate on engaging activities, with a primary focus on process rather than content. A key outcome of this study was an observed lack of a clearly formulated and articulated conceptual foundation for secondary level engineering. Regarding pedagogy, the researchers identified a heavy emphasis on modeling and applied learning. At the same time, the researchers observed a lack of emphasis on reflection and analysis of the pedagogical processes and techniques used to shape teachers’ ability to teach engineering to their students. The findings of the study also include concerns raised by teachers as they engage in engineering professional development. These include concerns about technical knowledge, particularly with the use of specialized software applications and other tools, as well as with practical issues such as time, resources, and availability of appropriate curriculum.     

Students' design of a biometric procedure in upper secondary school

Making the connection between science and technology might be important for students to learn to identify and solve problems and to acquire scientific knowledge and skills. The research reported in this article concerned the development of a design situation in a science classroom and the study of students performing in this situation. More specifically, the setting involved students’ design of a measurement procedure as a way of attaining understanding of the underlying scientific concepts. In fact, at higher secondary level, the classical experimental procedure of measuring facial angle is employed within the topic of human evolution to find out to which species a given human cranium belongs. At the same time, designing a procedure, instead of just executing it, is thought to entail higher odds for attaining teleological understanding. The development of the learning situation involved pursuing parallels between the expert design task as described in the literature and the assignment given to students. We proceeded through step-wise development of the learning situation that was successively tested out in the classroom. Our analysis of the student-devised procedures revealed three issues regarding the graphical representation of angles, the reproducibility of the points and the communicational demands of the situation. Students used both prior knowledge (e.g. about evolution), and new knowledge about cranium anatomy and angles. They also exhibited new experimental skills like anticipating each experimental action. Such cognitive tasks which are at the origin of students’ activity make the situation approximate the goals of laboratory work by distancing it from the simple execution of a series of steps. Future research could be directed towards further exploring the benefits of an approach that combines essential characteristics of science and technology.     

低温等离子体在材料表面改性中的应用

介绍了低温等离子体在材料表面改性方面的应用情况:用低温等离子体处理羊毛、棉、涤纶等纺织纤维材料,可提高纤维的吸附性、可染性、可纺性,并可结合各种功能整理剂赋予纤维以特殊的性能;金属材料表面经等离子体处理后,可提高耐磨性、抗腐蚀性、光滑度和装饰性;对塑料橡胶材料表面的等离子体处理可改善材料的粘结性、亲水性和电学性能;生物医用材料表面经等离子体处理可有效地改善血液相容性和组织相容性。     

有限元分析软件Marc及在橡胶材料分析中的应用

介绍了 Marc软件的组成和工作特点 ,详细介绍了其非线性分析功能在处理几何非线性、边界条件非线性、材料非线性等问题时所采用的分析模型和处理方法 ,重点阐述了进行橡胶材料分析时所采用的材料模型、分析方法和分析实例。该软件可以广泛用于橡胶元件设计的仿真预测和结构优化 ,是进行橡胶材料行为分析研究的一种有效手段     

The development from prototype construction to workshop production of an advanced underground locomotive: A case study

This paper reports on the problems encountered and their subsequent solution during the development and construction of an advanced locomotive from prototype to full production assembly. A fleet of these locomotives are to work in the UK National Coal Board's (NCB) Selby coalfield. In order to ensure that all the information was accurately recorded and could be applied to a reasonably precise point in the development process, visits were made to the company at intervals of about two weeks. In developing products of this nature a strongproblem solving capacity is a necessity and in the main it was found that engineering and theoretical design problems were solved quickly and once solved did not recur on subsequent units. Strong links between specialist suppliers and customers are vital, since components will often be used in unfamiliar applications and the customer may have to spend time carrying out applied development of suppliers' components. The development and production of the locomotive would have been aided by the NCB providing more accurate specifications, giving an indication of future volume requirements and being better prepared to site test the prototype after its delivery.     

STEM education in the twenty-first century: learning at work—an exploration of design and technology teacher perceptions and practices

Teachers’ knowledge of STEM education, their understanding, and pedagogical application of that knowledge is intrinsically linked to the subsequent effectiveness of STEM delivery within their own practice; where a teacher’s knowledge and understanding is deficient, the potential for pupil learning is ineffective and limited. Set within the context of secondary age phase education in England and Wales (11–16 years old), this paper explores how teachers working within the field of design and technology education acquire new knowledge in STEM; how understanding is developed and subsequently embedded within their practice to support the creation of a diverse STEM-literate society. The purpose being to determine mechanisms by which knowledge acquisition occurs, to reconnoitre potential implications for education and learning at work, including consideration of the role which new technologies play in the development of STEM knowledge within and across contributory STEM subject disciplines. Underpinned by an interpretivist ontology, work presented here builds upon the premise that design and technology is an interdisciplinary educational construct and not viewed as being of equal status to other STEM disciplines including maths and science. Drawing upon the philosophical field of symbolic interactionism and constructivist grounded theory, work embraces an abductive methodology where participants are encouraged to relate design and technology within the context of STEM education. Emergent findings are discussed in relation to their potential to support teachers’ educational development for the advancement of STEM literacy, and help secure design and technology’s place as a subject of value within a twenty-first Century curriculum.     

丙烯酸酯橡胶生产、应用与市场

随着我国汽车工业快速发展,对丙烯酸酯的需求日益增加.文章评述了丙烯酸酯橡胶的生产、市场需求和应用,重点介绍了丙烯酸酯橡胶的共混改性和加工技术,分析现状并提出我国丙烯酸酯工业发展的建议.     

The clock project: gears as visual-tangible representations for mathematical concepts

As we have noticed from our own classroom experiences, children often find it difficult to identify the adequate operations learned in mathematics class when they are solving mechanical-operators problems in Technology class. We wanted to design a project that exploits the idea of a hands-on relationship between mathematics and technology to teach students the concept of ‘transmission coefficient’ in schools. Our purpose was to bridge mathematical knowledge and mechanical parts in technological devices. Our belief was that visual-tangible representations enhance human cognition by scaffolding the information process. We supplied a kit with rubber foam (Fomi) and balsa wood parts to construct an analogical clock. This included a series of gears to work with three different ratios. The project was conducted in 2007 and 2008, with 38 students ranging from 10 to 14 years of age. The students were from the 5th and 7th grades in two different schools. The project included six stages of both theory and hands-on work. In a final stage, the students were given a written test. All students were able to make workable systems of their design for a time-measuring device. This proved important for technological education. On the other hand, manipulating gears along with visual reasoning strategies allowed all students to achieve an understanding of operations with fractions. We think this is a major achievement in mathematical education.