Four plates,photographed on March 17,1986 by Oversea Observation Team of CAS at Mount John Observatory,show the rays of Comey Halley.We scanned and measured three of them by the PDS micro-densitometer of PMO.The foldi...Four plates,photographed on March 17,1986 by Oversea Observation Team of CAS at Mount John Observatory,show the rays of Comey Halley.We scanned and measured three of them by the PDS micro-densitometer of PMO.The folding speed (towards the tail’s spine) of the rays and the motion of some matter in the tail were obtained.展开更多
Nowadays, PD （partial discharge） measurements are a crucial part of the preventive maintenance of electrical equipment within high voltage engineering. Especially for electrical machines, both the supplier and the u...Nowadays, PD （partial discharge） measurements are a crucial part of the preventive maintenance of electrical equipment within high voltage engineering. Especially for electrical machines, both the supplier and the user are interested in the results of PD measurements. However, PDs hardly represent the cause of the failure, more likely they are claimed as the outcome of a failure. This paper deals with the insulation of a 6 kV electrical machine, whereas PD measurements were carried out at a single stator from wound coils. During manufacturing, these coils were equipped with different materials for the OCP （outer corona protection）. Using different PD measurement systems and different bandwidths, investigations of the PD behavior of the coils were carried out. Additionally, the surface resistivity of the corona protection was determined. As a result, conclusions for the correlations between the resistance of the OCP as well as the PD behavior are stated. Furthermore, the influence of using different measurement systems, different measuring circuits, and different bandwidths is shown.展开更多
Teacher evaluations intend to cultivate quality among teachers. However, since they are traditionally dependent on observers and their reports that are likely biased, the procedures probably effectuate discords among ...Teacher evaluations intend to cultivate quality among teachers. However, since they are traditionally dependent on observers and their reports that are likely biased, the procedures probably effectuate discords among the calling-teaching professionals. An evaluation procedure that can ascertain fairness in the decisions about teacher retentions, terminations, promotions, and sanctions can capture the accordance of all teachers and teacher facilitators. This paper identifies the possibility of such an evaluation system that is built upon the existing value-added methods. Drawing upon the observations and recommendations by Chetty, Friedman, and Rockoff （2012） on value-added methods of evaluation, and considering the uniqueness of ELTs （English Language Teachers） as it was observed by Borg （2006） and Lee （2010）, this paper describes the application of the value-added evaluation method, in gauging the quality of ELTs. The paper further explicates the vantages and conformities embodied in the procedure that could boost up the morale of ELTs as independent professionals of a creative art, and help them perform to their fullest potential展开更多
文摘Four plates,photographed on March 17,1986 by Oversea Observation Team of CAS at Mount John Observatory,show the rays of Comey Halley.We scanned and measured three of them by the PDS micro-densitometer of PMO.The folding speed (towards the tail’s spine) of the rays and the motion of some matter in the tail were obtained.
文摘Nowadays, PD （partial discharge） measurements are a crucial part of the preventive maintenance of electrical equipment within high voltage engineering. Especially for electrical machines, both the supplier and the user are interested in the results of PD measurements. However, PDs hardly represent the cause of the failure, more likely they are claimed as the outcome of a failure. This paper deals with the insulation of a 6 kV electrical machine, whereas PD measurements were carried out at a single stator from wound coils. During manufacturing, these coils were equipped with different materials for the OCP （outer corona protection）. Using different PD measurement systems and different bandwidths, investigations of the PD behavior of the coils were carried out. Additionally, the surface resistivity of the corona protection was determined. As a result, conclusions for the correlations between the resistance of the OCP as well as the PD behavior are stated. Furthermore, the influence of using different measurement systems, different measuring circuits, and different bandwidths is shown.
文摘Teacher evaluations intend to cultivate quality among teachers. However, since they are traditionally dependent on observers and their reports that are likely biased, the procedures probably effectuate discords among the calling-teaching professionals. An evaluation procedure that can ascertain fairness in the decisions about teacher retentions, terminations, promotions, and sanctions can capture the accordance of all teachers and teacher facilitators. This paper identifies the possibility of such an evaluation system that is built upon the existing value-added methods. Drawing upon the observations and recommendations by Chetty, Friedman, and Rockoff （2012） on value-added methods of evaluation, and considering the uniqueness of ELTs （English Language Teachers） as it was observed by Borg （2006） and Lee （2010）, this paper describes the application of the value-added evaluation method, in gauging the quality of ELTs. The paper further explicates the vantages and conformities embodied in the procedure that could boost up the morale of ELTs as independent professionals of a creative art, and help them perform to their fullest potential
