Grounded in social cognitive theory and expectancy-value theory, the current study aimed to present a demotivation scale -Learner Perceptions of Demotivators Scale (LPDS)designed specifically for use in L2 research and tested empirically to provide evidence of its construct, validity, and reliability. Study 1 sample consisted of 295 Chinese college English learners. An exploratory factor analysis offered preliminary support for a factor structure comprising three dimensions: negative teacher behavior, loss of task value, and low expectancy for success. Study 2 sample consisted of another 320 Chinese college English learners. The proposed factor structure was further corroborated through confirmatory factor analysis, and support for its validity was provided by means of correlating the three dimensions with academic performance and self-efficacy measures. Specifically, all the correlations were negative except for the positive association between academic performance and negative teacher behavior. Further, whereas the model fit confirmed a well-fitting second-order model, one low first-order loading (negative teacher behavior) does not seem to support a second-order factor model. Therefore, the three dimensions should be regarded as separate to best capture the nuances of different demotivators. By establishing a nomological network (demotivation, academic performance, and self-efficacy), the current study illuminates selected aspects of ESL pedagogy.

A new-style slick pole self-lock up-down setting is designed to realize large size up-down of crossbeam, its principle is that crossbeam’s “limitless” pass is realized by alternate motion of an overtop elastic cannula and a ringent elastic cannula connected with poles. FEM is used to calculate proper interference value to guarantee that elastic cover can move freely when it is pressed and it can be locked when it isn’t pressed. A new-style slick pole self-lock up-down setting’s design is based on it. Simulation analysis and practical application shows that this method is feasible.

In order to eliminate thermal deformation of large-scale precise machine tools caused by ambient temperature change, self-alignment design principle and key points are proposed for a large-scale precise machine tools, Self-alignment simulation experiment, machined parts experiment and compared results for self-alignment rail grinder and other similar products are analysed, the present analysis show that self-alignment rail grinder has many advangtages of good precision, straightness stability.