Smart structures and materials

A structure is an assembly that serves an engineering function. It is reasonable to expect that all engineering design should be smart, and not dumb. But one can still make a distinction between smartly designed structures and smart structures. The latter term has acquired a specific technical meaning over the last few decades. A smart structure is that which has the ability to respond adaptively in a pre-designed useful and efficient manner to changes in environmental conditions, including any changes in its own condition; the response is adaptive in the sense that two or more stimuli or inputs may be received as anticipated and yet there is a single response function as per design. Smartness ensures that the structure gives optimum performance under a variety of environmental conditions. While structures with some degree of smartness have been designed from times immemorial, the current activity and excitement in this field derives its impetus from the level of sophistication achieved in materials science, information technology, measurement science, sensors, actuators, signal processing, nanotechnology, cybernetics, artificial intelligence, and biomimetics.     

Helical angle measurement of worm by a coordinate measuring machine and its uncertainty evaluation

The purpose of the study concerns the measurement of worm’s helical angle by a coordinate measurement machine in the ambient industrial environment. The novel measurement method and sampling strategy were described firstly. This method used the coordinate measurement machine to measure both of the worm gear’s left and right surfaces. The worm surface was reconstructed based on the measured data of all the sampling points. Then a middle cylinder was established to truncate the fitted worm surfaces, and the truncated spiral lines were straightened to calculate the helical angle. The measurement uncertainty of worm’s helical angle was evaluated by taking the difference of calculated helical angles along the truncated spiral lines on both the left and right side surfaces of the worm. Twenty-four measurement experiments show that the maximum measurement error of the proposed method is 0.105, and the measurement error ratios are all less than 3.5?. The result means that the measurement method can realize the precision measurement of worm’s helical angle and can be employed in the generally industrial application.     

矿井多风机风压优化计算机调节系统设计

经过对多风机通风网络分析,利用现有的VNETPC模拟程序,建立了多风机风压优化计算机调节系统.该系统允许计算机自动调整多风机风压,直到各用风地点获得最佳可接受的风量分配为止.     

Splicing-site recognition of rice (Oryza sativa L.)DNA sequences

INTRODUCTIONCorrectlypinpointingsplicing sitesingenomicDNAsequencesisnotaneasytask ,whichisofgreatimportancetothegenomeannotationandgenefinding .Intronsaregenerallydividedinto3classes,namelycalssI,classIIandcommonnu cleuspre mRNA .IntronofclassIandIIcango…     

基于非机械类专业机械基础课程双语教学的实践和探讨

为了适应全球化经济发展的需要,提高所培养人才的国际竞争力,围绕机械基础双语教学中教材的选用,教学过程和考核方式进行了探讨。采用了适合学生的双语教学模式和实施方法,取得了良好的教学效果。     

创建精品课程提高教学质量

建设精品课程的目的是通过为学生提供优质教学资源来提高教学质量。本文结合机械原理精品课程建设,从课程体系、教学内容、师资队伍建设、教材建设、教学方法和手段等几方面进行了探索和实践,并取得标志性成果。     

船舶起货机微机控制装置及其高可靠性保护

本文主要介绍国产微机控制装置在船舶起货机中的应用及其发展情况,论述控制装置的功能与高可靠性保护。     

旧绳带新绳在提升绳更换中的应用

近几年来,随着煤矿的产量逐渐增加,提升绳的直径也逐渐增大;另外,在更换首绳时,矿方给定工期较紧,一般在矿井大修时进行,再加上作业时间长,动用人员多,劳动强度大,作业环境差,作业难度大;研究一种经济实用、简便快捷、安全高效的换绳方法,是一项关系煤矿安全生产工作的迫切任务;介绍旧绳带新绳在皖北煤电集团钱营孜煤矿副井多绳摩擦式提升机中的应用。     

Xerox Project: Photocopy Machines as a Metaphor for an “Open Society”

This article shows how various meanings of a new communication technology are born or get transformed when placed in a different political context via a case study of a program organized by the Soros Foundation in 1984 to promote democratic values (the idea of an “open society”) in Hungary. This program, called the Xerox project, helped hundreds of public institutions acquire photocopy machines. Under the suppressive Hungarian regime of the 1980s the appearance of photocopy machines as a new means of copying texts had serious political consequences. By means of historical research and expert interviews, this article analyzes the nature of these consequences and examines how certain meanings and uses of photocopy machines evolved in the latter half of the 1980s.