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In order to explore the mechanism of inhibitor on coal spontaneous combustion, the oxygen-containing groups aldehyde （-CHO） and methoxy（-OCH3） in coal molecular side chain were selected as the subjects of the study. The geometric configuration, electrostatic potential, reaction tendency, frontier orbitals, natural bond orbitals and charge transfer of the oxygen-containing groups（-CHO and -OCH3） and their complexes with Na+, Ba2+ and Ca2+ were deeply studied by using Gaussian 16W simulation software. The results show that Na+, Ba2+ and Ca2+ tend to cooperate with the oxygen-containing groups to form complexes, which weakens the electrophilic reaction ability and disables the nucleophilic reaction ability of -CHO and -OCH3 oxygen-containing groups, thus reducing the chemical activity of oxygen-containing groups. Metal ions increase the energy level difference（ELOMO-EHOMO） and the absolute value of the highest occupied molecular orbital（HOMO） energy of oxygen-containing groups, and thereby increases the stability of oxygen-containing group. The results of natural bond orbital theory analysis（NBO） shows that -CHO and -OCH3 oxygen-containing groups can coordinate steadily with Na+, Ca2+ and Ba2+, and the electrons of O in the two the groups transfer to Na+, Ca2+ and Ba2+ to form coordinate bonds. The combination of oxygen-containing groups with metal ions reduces the chance of contact between oxygen-containing groups and oxygen, which inhibits coal spontaneous combustion.

Pearl River Delta is the most densely populated and urbanized area in China. As the pilot area of reform and opening up, Pearl River Delta takes the lead in its urbanization in China and represents the development trend of China's urbanization. Therefore, a great number and diversity of previous studies on urbanization in the Pearl River Delta warrant further review and reflection. This study focused on publications about urbanization in the Pearl River Delta from 1983 to 2020 in the collection of Chinese core journals and dissertations in the China Academic Journals Full-text Database (CNKI). The quantitative characteristics of published papers, the scientific cooperation network of core authors and institutions, research topics, and historical research hotspots were analyzed for different periods through bibliometrics and mapping knowledge domains based on CiteSpace. Results indicated that: (1) the number of publications of the relevant research showed an upward trend, which was divided into the following four stages: initial (1983-1991), exploratory (1992-2002), prosperity (2003-2011), and deep cultivation (2012-2020) stages. (2) The research institutions gradually expanded from south China universities, with Sun Yat-sen University emerging as the core to form a national network of research collaboration, and the scholar network has expanded from occasional collaboration to form a variety of cooperation networks within and across institutions. (3) In the evolution process of knowledge, research topics that scholars focused on included economic zone, rural urbanization, urban agglomeration, Guangdong-Hong Kong-Macao Greater Bay area, new-type urbanization, innovation, while other historical hotspots that scholars focused on included economic zone, new-type urbanization, and Guangdong-Hong Kong-Macao Greater Bay area. (4) The research showed the characteristics of policy and practice orientations, the continuous expansion of vision and scope, and the theoretical research stages evolving from lag to advance and then to synchronization. After the urbanization development stage of a metropolitan circle and urban agglomeration was jointly entered, the theoretical construction of localization was slightly insufficient, and that of the people-oriented urbanization mode was lacking. (5) Pearl River Delta entered the regional urbanization stage, with the metropolitan areas and urban agglomerations being the main body. The driving force of urbanization development shifted to scientific and technological innovation, while the development features shifted to intensive, high-quality, and people-oriented urbanization. Finally, this study argued that future studies on urbanization in Pearl River Delta should focus on the theoretical and practical pathways of the coordinated development of urban agglomeration in the Guangdong-Hong Kong-Macao Greater Bay area, innovation-driven development strategy, and people-oriented urbanization.

In order to prevent and control the emission of toxic and harmful gases in the goaf of close coal seams, it is of great significance to study its distribution and migration behavior. Taking 1818 working face of Jinshen Shaping Coal Mine in Shanxi Province as an example, the gas composition and volume fraction of equal interval measuring points in goaf and working face are obtained by arranging beam tube monitoring system and manual sampling method. By studying the spatial distribution of the gas in the upper and lower coal seams before and after the solid coal mining of the lower coal seam, the static and dynamic distribution laws of the gas in the upper and lower goafs within the range of 90 m in front of the goaf and 180 m behind the goaf are obtained respectively. Based on the spatial and temporal distribution characteristics of the gas in the upper and lower goafs, the four aspects of the migration mechanism of the gas in the goaf of the close-distance coal seam mining are discussed. It is found that during the mining process, the toxic and harmful gases in the close-distance goaf show a significant spatial and temporal distribution law of agglomeration to the return air side due to the multiple effects of air leakage diffusion, gas migration effect in the upper and lower goaf and coal-oxygen reaction.

Lithium–sulfur batteries (LSBs) have attracted considerable attention due to their high capacity and energy density, however, the electrochemical performance of LSBs was limited by the difficult conversion of lithium polysulfides (LiPSs). Coordination supramolecular networks (CSNs) have flexible structures, abundant active sites, and intermolecular interactions, which can facilitate the transformation of LiPSs and ion/charge transport. Herein, we combined a zinc coordination supramolecular network (Zn-CSN) with MnO2 to synthesize Zn-CSN@MnO2via a one-pot method. Zn-CSN@MnO2 accelerates the evolution of LiPSs and promotes the migration of lithium ions. Zn-CSN@MnO2 as a sulfur host in LSBs displays outstanding rate performance (406.55 mAh g−1 at 4C). It has a high initial specific capacity of 1027.89 mAh g−1 at 0.5C, cycling 150 cycles with a capacity loss of 0.2% per cycle. Surprisingly, it runs 400 cycles at a high current density of 5C with a capacity retention of 80.5%. This synergistic strategy for CSNs and oxides has brightened the prospects of the practical applications of LSBs. [ABSTRACT FROM AUTHOR]

Long-term rental apartments as a new business form in the real estate market have become more and more popular with consumers and the real estate industry due to an increase in the floating urban population and changes in people's living concepts. It is thus important to provide some guarantees in the implementation of a housing policy for "rent and purchase simultaneously." In this paper, in-depth interviews were conducted with 21 tenants who had experience in long-term apartment rental in Guangzhou. The interview data were encoded level by level using grounded theory. Finally, based on the theory of planned behavior, a model for the influencing mechanism for long-term apartment rental intention in Guangzhou was constructed. The model includes three main categories: rental attitude, subjective norms, and perceptual behavior control with six subcategories. The results show that rental intention for long-term rental apartments in Guangzhou is influenced by rental attitude, subjective norms, and perceptual behavior control. Rental attitude is composed of endogenous attitudes and exogenous attitudes. In addition to the housing demand function, risk judgment, and additional interest, the internal degree of emotional demand and brand preference also affect intention to rent. Subjective norm is composed of directive norms and demonstrative norms, while an individual's cognition of rental policy and social media guidance are important components of directive norms. Perceptual behavior control is composed of self-efficacy and facilitation, while access conditions are an important part of facilitation. The government is an important body to promote the harmonious development of the long-term apartment rental market, and needs to cultivate professional rental institutions, innovate rental modes, and establish a long-term apartment rental price supervision mechanism. The government needs to issue corresponding rules and regulations, such as provide clearer and more convenient procedures, improve the supervision system, and protect the rights and interests of tenants. The government also needs to introduce corresponding preferential policies and determine access conditions. Operators of long-term rental apartments should not only meet the functional needs of tenants, but also pay attention to their additional needs. Furthermore, they should provide a variety of social activities. Based on the needs of different groups, the operators could develop apartments for blue-collar workers, family rental apartments, and so on. Based on the theory of planned behavior, this paper explores the influencing mechanism for long-term rental intention in Guangzhou. The study enriches the research of the theory of planned behavior in the field of rental housing, and provides a reference for the government to strengthen the management of the rental market. At the same time, it is helpful for enterprises to understand the needs and expectations of tenants. The study also provides additional information for enterprise management, product design, and brand promotion.

Land-use conflicts (LUCs) are pivotal in assessing human–land interaction, reflecting the intricate interplay between natural and anthropogenic drivers. However, existing studies often overlook nuanced non-linear responses and critical threshold recognition, focusing solely on linear correlations between isolated factors and LUCs. This study, situated in Xinjiang, China's arid and semiarid region, introduces a novel analytical framework and threshold application model for LUCs. Integrating land-use and socioeconomic data, we quantified LUCs using Fragstats, correlation analysis, and restricted cubic spline (RCS) regression. Exploring non-linear dynamics between LUCs and 14 potential drivers, including natural and anthropogenic factors, we identified critical thresholds. LUC zones were delineated using a four-quadrant method, allowing tailored mitigation strategies. Our findings reveal Xinjiang's distinct LUC spatial pattern, with intense conflicts surrounding mountainous areas and milder conflicts in basin regions, showing marked diminishment from 2000 to 2020. RCS effectively identifies LUC thresholds, indicating persisting severity pre- or post-specific thresholds. Xinjiang's LUCs are categorized into key control areas, urgent regulation zones, elastic development territories, and moderate optimization regions, each with significant regional disparities. Tailored optimization suggestions mitigate linear analysis limitations, providing a fresh perspective on land zoning optimization. This research supports comprehensive land management and planning in Xinjiang, China. [ABSTRACT FROM AUTHOR]

Although high-quality tourism destinations directly determine the tourism experiences of tourists and the management focuses of tourism management departments, existing studies have paid little attention to the relationship between tourism destinations of differing quality and tourist experiences. This study analyzed the spatiotemporal distribution of tourists and the quality of tourism destinations in Urumqi based on Tencent migration big data and Weibo sign-in big data and ultimately determined whether there are spatial correlations between the two. The results show that there are large differences in quality between different tourist destinations, and although the spatial and temporal distribution of tourists is not strongly correlated with the quality of tourist destinations, we can divide tourist destinations into four categories based on the correlations between the two (e.g., high-quality tourist destinations with a low number of tourists). The results of this study provide tourists with examples of high-quality tourist destinations, thus improving their holiday experiences, and they also provide a basis by which tourism management departments can manage and develop tourist destinations. The results of this study can also be extended to other regions and play a positive role in promoting the development of the tourism industry. [ABSTRACT FROM AUTHOR]

The digital economy plays an important role in the high-quality development of cities, and low-carbon urban development is an integral part of this evolution. Therefore, it is important to explore the impact of the development of the digital economy on urban carbon emissions. By considering 21 cities in Guangdong Province as the object of the research, this study measured the levels of the digital economy from 2011 to 2019 by using an entropy weight-based TOPSIS model, analyzed the spatiotemporal changes, and used geographically and temporally weighted regression to examine the spatiotemporal heterogeneity of the impact of the digital economy on urban carbon emissions. The results showed the following: (1) The development of the digital economy in Guangdong Province in general exhibited a stable trend of growth, and the average level of its development in the 21 cities considered increased by 3.4 times during the study period. (2) The level of development of the digital economy in the Pearl River Delta was significantly higher than that in northern, western, and eastern Guangdong, with Shenzhen being the most developed city in this regard (0.8473), and Shanwei being the least developed (0.0633). (3) The impact of the development of the digital economy on carbon emissions had significant spatiotemporal heterogeneity. The benefits of the development of the digital economy in terms of a reduction in carbon emissions was the most significant in the Pearl River Delta, and regional differences were prominent. (4) The reductions in carbon emissions in cities with a highly developed digital economy were more significant than has been reported in past studies in the area. However, it had a negative effect on the urban carbon emissions in cities with a poorly developed digital economy. The results of this study can be used to guide policies related to the high-quality development of the urban digital economy. [ABSTRACT FROM AUTHOR]

Migrant workers moving to urbanized areas constitute a floating labor pool that provides flexible and cheap labor for urbanization processes. The Thirteenth National People's Congress of the People's Republic of China proposed the "acceleration of citizenization of rural migrant workers". Promoting the citizenization of migrant workers has always been a focus of the government and aca-demia as well as a fundamental part of China's new urbanization strategy. Based on the questionnaire data of 1 270 migrant workers of the Pearl River Delta in 2017, this paper adopts the multinomial Logistic regression analysis to explore the residential choice and influencing factors among four types of migrant workers' families, which are childless family (I), parents and minor children combined family (ii), unmarried children and their parents combined family (iii), and empty-nest family (iV), from the perspective of the family life cycle. The results show that: 1) The average age, the length of residence, the level of education, the average monthly income, and the per capita living area of the four types of families show regular differentiation. 2) The residential choice of 4 types of families is mainly in urban villages; Types I and IV prefer to select factory dormitories and affordable housing communities, respectively, while types II and III prefer to select commodity housing communities. 3) The main influencing factors of the residential choice of migrant workers in the Pearl River Delta are family type, individual factor, rural factor, migration factor, and location factor. Based on the results of this study, we put forward community-based policy suggestions for citizenization strategy [ABSTRACT FROM AUTHOR]