Constraints on the Dark Side of the Universe and Observational Hubble Parameter Data

This paper is a review on the observational Hubble parameter data that have gained increasing attention in recent years for their illuminating power on the dark side of the universe --- the dark matter, dark energy, and the dark age. Currently, there are two major methods of independent observational H(z) measurement, which we summarize as the "differential age method" and the "radial BAO size method". Starting with fundamental cosmological notions such as the spacetime coordinates in an expanding universe, we present the basic principles behind the two methods. We further review the two methods in greater detail, including the source of errors. We show how the observational H(z) data presents itself as a useful tool in the study of cosmological models and parameter constraint, and we also discuss several issues associated with their applications. Finally, we point the reader to a future prospect of upcoming observation programs that will lead to some major improvements in the quality of observational H(z) data.Comment: 20 pages, 6 figures, and 1 table, uses REVTeX 4.1. Review article, accepted by Advances in Astronom

The Training of Newly Recruited Teachers in English Test Preparation Schools in China: A Case Study

English test preparation schools are becoming increasingly popular in China as students seek to prepare for entrance exams into international schools, and consequently the number of English language teachers in China has substantially increased. However, these teachers do not all have consistent training, an oversight that may negatively impact student outcomes, and there is limited research on these training methods. Therefore, the current study explores and evaluates the training methods used at an English test preparation school in China. The research employs a qualitative approach that includes semi-structured interviews with 12 new teacher trainees who work at an English test preparation school in a major city of the northwestern part of China. The study concludes that factors such as the analysis of new teacher trainees’ academic backgrounds and training expectations, trainers’ proficiency, provision of training materials and the evaluation feedback to the teacher trainees contribute greatly to the level of teacher trainees’ satisfaction towards the training. Overall, the findings of this study potentially benefit English test preparation schools, which can adjust their new teacher-training program to better meet the needs of teacher trainees

A link density clustering algorithm based on automatically selecting density peaks for overlapping community detection

Peer reviewedPostprin