The paper aims to explore the effect of problem-based learning (PBL) embedding degree and education level on individual perception, as well as the moderating effect of nationality.

The paper first conceptualizes PBL embedding degree which means the extent of applying PBL. It takes an empirical study on an international MBA class in one of the first-class universities in China. An investigation is taken with the designed “PBL-based Cognitive Perception Scale” and an Ordered Probit Model is constructed.

The findings of this study are as follows: PBL embedding degree has a significant effect on the cognitive perception of student, which varies in different dimensions; the educational level of international student positively affects the cognitive perception toward PBL; and nationality may moderate the relationship between the PBL embedding degree and individual perception.

The paper replenishes the investigation and application of Bloom’s Taxonomy of Learning. By conceptualizing PBL embedding degree, the paper extends the research perspectives of PBL and proposes a subjective method on the evaluation of PBL. The paper also may provide a guidance for PBL curriculum design with sustainable development of education.

This study aims to analyze the structural characteristics of knowledge exchange in Zhihu Lives to provide feasible suggestions for improving the creative enthusiasm of knowledge providers.

This paper uses the domain classification of Zhihu Lives to construct a cross-domain knowledge exchange network.

This research makes the following findings: the small-world effect exists in the sponsorship network and is conducive to enhancing the learning willingness of knowledge providers; significant sponsorships and strong learning willingness exist among knowledge providers; the knowledge exchange is obvious among the fields of education, reading and writing, business and lifestyle and the fields of music, film, games, art, the internet, science and technology, design, financial economy and occupation; and knowledge exchange is obvious among the internal fields of education, reading and writing, and business and life style, between the internal fields of music, film, and games and art and between the internal fields of the internet, science and technology, design, financial economy and occupation.

This study can provide practical suggestions for the following development of the platform by analyzing the special phenomenon of knowledge exchange in the present stage of knowledge exchange.

The encrypted money market has attracted the attention of investors all over the world. Among the encrypted currency, bitcoin is undoubtedly the most popular. Because blockchain technology is the crucial support of bitcoin, exploring the relationship between bitcoin and the blockchain index is necessary.

This paper uses the Granger causality test to explore the correlation between bitcoin and the blockchain index. Furthermore, their volatility is analyzed by a GARCH-class model.

The results show that no significant correlation exists between bitcoin and the blockchain index; external shocks aggravate the volatility of bitcoin and the blockchain index, and the volatility has a certain degree of sustainability; and blockchain index has obvious leverage, namely, its decline has a stronger impact.

The volatility of bitcoin and the blockchain index is crucial for investors.

Knowledge sharing has entered the stage of knowledge payment with the typical models of paid Q&A, live session, paid subscription, course column and community service. Numerous knowledge suppliers have begun to pour into the knowledge payment market, and users' willingness to pay for premium content has increased. However, the academic research on knowledge payment has just begun.

In this paper, the authors searched several bibliographic databases using keywords such as “knowledge payment”, “paid Q&A”, “pay for answer”, “social Q&A”, “paywall” and “online health consultation” and selected papers from aspects of research scenes, research topics, etc. Finally, a total of 116 articles were identified for combing studies.

This study found that in the early research, scholars paid attention to the definition of knowledge payment concept and the discrimination of typical models. With the continuous enrichment of research literature, the research direction has gradually been refined into three main branches from the perspective of research objects, i.e. knowledge provider, knowledge demander and knowledge payment platform.

This paper focuses on discussing and sorting out the key research issues from these three research genres. Finally, the authors found out conflicting and contradictory research results and research gaps in the existing research and then put forward the urgent research topics.