With the improvement of people's living standards, water heaters almost into the various households. In the energy-saving emission reduction has become the trend of the times today, saving energy and reducing carbon emissions is the most fashionable way of life. Air source heat pump water heaters are increasingly being used in people's lives. It is well known that it has many advantages, safety, energy saving, comfort, environmental protection, but there are some factors that affect its development and promotion. This paper mainly discusses the development history of air source heat pump technology at home and abroad, working principle, working flow, turbo technology at present stage, efficient heat exchange, and the research status of air source heat pump technology, such as new type refrigerant and dual frequency compression frequency conversion, then it discusses the application of air source heat pump technology, has the advantage, and finally discusses its application and the existence of two major problems and suggestions for improvement.

Salicylaldehyde imine transition metal catalyst is a kind of olefin polymerization catalyst that is widely used in the coordination of salicylaldehyde imine ligand and pre-transition metal. Salicylaldehyde imine ligands have the characteristic of easily inserting different substituents via organic synthesis. Therefore, the regulation of the polymerization activity, polymerization product, and product distribution can be achieved by changing the steric hindrance effect, the electronic effect, and the number of metal active sites near the catalytic active center. The development status of the transition metal catalyst of salicylaldehyde imide was summarized in this paper. The influence of the ligand structure of the salicylaldehyde imide transition metal catalyst on the catalytic performance, which involved the high selectivity of ethylene trimerization, ethylene/α-olefin, polar monomer copolymerization, ethylene polymerization production, ultra-high molecular weight polyethylene, and many other areas of olefin polymerization, was elaborated, providing references for further study and industrial applications of this catalyst.

Contemporary infrastructure research has its origins in the late 1980s as attempts were made to measure the economic impact of public expenditures with early mixed results. In the 1990s, infrastructure assumed greater importance as a policy solution to improve economic performance in low-income economies particularly by multilateral development and official development agencies. This interest led to greater research interest with the examination of infrastructure and economic development, foreign direct investment, the role of institutions and capital markets, procurement, regional economic effects and more recently, the productivity of public investment in specific regions and industries. 

This article identifies subjects that warrant further research in the future particularly the shortfall in current investment levels and how this will be met. This is a challenge for both low and high-income countries with fiscal and public debt constraints requiring governments to tap alternative sources of finance. Policy options available to government include wider use of bond markets and private participation in infrastructure provision and management. Other problems facing government include optimism bias and forecasting error that is a particular problem for projects in the transport sector. 

Many other research opportunities remain to be explored and this article is designed to provide an overview of several of the subjects that would benefit from further research at the present time. 

This systematic literature review examines the convergence of entrepreneurship and information technology between 2005 and 2024. It investigates how the emergence of information technologies such as social networks, smart devices, big data, and cloud computing have transformed business operations and entrepreneurial approaches. The study use technologies such as Bibliometrix to analyze academic literature and identify research trends, knowledge structures, and their evolutionary routes. During the specified time frame, a grand total of 292 articles were published by 777 writers. These publications have played a key role in redirecting academic focus from traditional entrepreneurship to the field of digital entrepreneurship and the applications of information technology. A thematic analysis uncovers a shift from theoretical investigation to practical implementations and multidisciplinary research, while a co-citation analysis highlights important contributors and influential works. This study emphasizes the crucial importance of information technology in influencing entrepreneurial behaviors and strategic business decisions. It also offers valuable insights for future research and entrepreneurial practice in the information age.

Creative cities as a study discipline have garnered extensive attention and research in theory and practice as a practical approach to urban revitalization and sustainable development. This study conducted a systematic review of academic research on creative cities. Utilizing the visual analysis tools Citespace and VOSviewer, a comprehensive analysis was performed on 570 relevant articles from the Web of Science database. This study analyzed the most influential publications, authors, journals, institutions, and countries within the sample. The investigation spans various disciplinary domains, including geography, environment, culture, and others. Additionally, an exploration of the structure and characteristics of co-cited references was undertaken to enhance our understanding of the theoretical foundations of creative cities research further. Among these, the focal points of the study encompass urban development, urban policies, and the challenges faced. Finally, through co-occurrence analysis of keywords and examining the evolutionary process, the study forecasted that future trends will focus on the practical application of cities to enhance the urban image and improve urban governance from multi-dimensional perspectives such as creativity-related cultural places, public art, and so forth, exploring novel models of creative cities from case to universal. The results of this study can support scholars in grasping the development trends and exploring focal points.

In 2015, the newly built undergraduate colleges have accounted for half of the ordinary undergraduate colleges. Through the investigation, it is concluded that the newly built undergraduate colleges in Sichuan have the following commonalities in the transformation: the school positioning of "application-oriented"; The embodiment of the new university spirit of "serving local construction"; The talent training goal of "innovative and composite applied talents"; Flexible personnel training curriculum system.