This paper explores the time-varying interaction between El Niño phenomenon and the oil market by applying the wavelet analysis. Few studies have explored the time-varying interrelationship between El Niño phenomenon and oil price (also the prices of petroleum products) by considering the time and frequency domains, and this paper will fill the above gaps. The empirical results reveal that El Niño index (NINO) which reflects the strength of El Niño phenomenon has a negative influence on oil price (OP) in the long run, but this view does not hold in the short and medium terms. These results are not consistent with the intertemporal capital asset pricing model (ICAPM), which indicates that there is a positive influence from NINO to OP. In turn, OP positively affects NINO in the medium term. Through comparing the five petroleum products, we can conclude that heating oil price (HOP) is the most relevant to NINO, while gasoline price (GOP) and diesel fuel price (DOP) have relatively weak relationships with it. Understanding the interactions between El Niño phenomenon and the oil market can provide insights for the investors, oil enterprises and related authorities.

Technological progress is an important way to realize the coordinated and stable development of economy and environment, and it is also a key factor to promote sustainable development. In the face of a large amount of literature data, traditional qualitative literature analysis methods have certain limitations and cannot objectively show the frontier trends of the research. Therefore, this article uses knowledge graph quantification and bibliometric analysis as research methods to quantitatively analyze technological progress. With the help of CiteSpace bibliometric tool and Web of Science database, this article draws the knowledge map, showing the basic characteristics, evolution logic, and hot frontiers of technological progress in the past 30 years, in order to grasp the new trend of technological progress research. The results show that: the number of studies on technological progress is increasing year by year, and China is the country with the largest number of publications. Research on technological progress mainly focuses on resource labor-intensive industries on land, while less attention on ocean. The evolution of technological progress is characterized by three stages: theoretical exploration (1997-2005), empirical analysis (2006-2016), and application exploration (2017-2021), and the path analysis and the impact mechanism of technological progress in the field of energy conservation and emission reduction are the focus of scholars at this stage. Finally, this article makes prospects from the aspects of research perspective, theme and content, so as to provide a reference basis for promoting scientific decision-making of sustainable development.

Based on meta index theory, this paper proposes an indicator system and a synthetic assessment model, which is used to assess the regional sustainable development on county level for Qingyang. And then, the paper respectively analyzes the characters of temporal and spatial evolvement on the subregional sustainable development in Qingyang from 1990 to 2008. The outcome shows that the integrated sustainability as a whole increased gradually from 1990 to 2008, where the driving force is due to the rapid growing of the economy and society along with the cost of abundant resources consumption and ecosystem degradation. At present, the integrated sustainability in some counties began to decrease.