排序方式： 共有3条查询结果，搜索用时 15 毫秒
1
1.
Yuan-feng DUAN Ru ZHANG Yang ZHAO Siu-wing OR Ke-qing FAN Zhi-feng TANG 《浙江大学学报(A卷英文版)》2011,12(12):895-901
Steel structures are widely used in railway infrastructures. Their stress state is the most important determinant of the safety
of these structures. The elasto-magnetic (EM) sensor is the most promising for stress monitoring of in-service steel structures.
Nevertheless, the necessity of magnetic excitation to saturation due to the use of a secondary coil for signal detection,
keeps from its engineering application. In this paper, a smart elasto-magneto-electric (EME) sensor using magneto-electric
(ME) sensing units to take the place of the secondary coil has been exploited for the first time. The ME sensing unit is made
of ME laminated composites, which has an ultrahigh ME voltage coefficient and can measure the magnetic induction simply and
precisely. Theoretical analysis and characterization experiments firstly conducted on the ME laminated composites showed that
the ME sensing units can be applied in the EM sensor for improved performance in stress monitoring. A tension test of a steel
bar was carried out to characterize our smart EME sensor and the results showed high accuracy and sensitivity. The present
smart EME sensor is a promising tool for stress monitoring of steel structures in railway and other civil infrastructures. 相似文献
2.
3.
Seeing the ‘new’ in light of the ‘old’: evolving interpretations of a new national English curriculum 总被引：1，自引：0，他引：1
This 2‐year longitudinal study explores the process by which three populations of practitioners (mentors, co‐ordinators, and teachers) interpreted a national curriculum involving a change in policies for teaching English as a foreign language. The analysis revealed that the process of managing the changes brought about by the new curriculum yielded ‘dialogues of practice’ between ‘old’ and ‘new’. These dialogues engaged mentors, co‐ordinators, and teachers alike in mediating between new understandings and old ones. It addresses the ways in which they made sense of the terminology of the new curriculum in light of the old curriculum, negotiated between new pedagogical content knowledge and ingrained conceptions of subject‐matter teaching, adapted old understandings of testing to new conceptions of performance‐assessment processes, and mediated between their need to preserve a sense of professional competence while feeling destabilized as ‘novices’ as they confronted innovative curricular practices. Participants' strategic need to ‘survive’ the changes resulted in the development of networks to support professional exchange and assist teachers in managing their way through the uncertainty of curricular change. 相似文献
1