Sustainable Recycling Mechanisms for Waste Cooking Oil in China’s Third-Tier Cities: Evidence from Restaurant Practices

The conversion of waste cooking oil (WCO) into biodiesel is a key strategy for advancing energy sustainability, particularly within China’s rapidly expanding restaurant industry. In third-tier cities such as Shantou, Guangdong Province, WCO collection faces unique challenges. Through in-depth interviews with 20 restaurant operators, this study identifies multiple barriers to effective WCO management, including an aging population, underdeveloped local economies, limited technological infrastructure, and unequal access to educational opportunities, all of which hinder the adoption of advanced filtration systems and broader environmental sustainability initiatives. Moreover, the non-standardized operations of third-party WCO collection services, coupled with space constraints in small restaurant kitchens, further exacerbate inefficiencies in recovery processes. To address these challenges, this study develops a comprehensive framework for WCO collection that is adaptable to regions with similar socio-economic conditions. Integrating grounded theory, Interpretive Structural Modeling (ISM), and Latent Dirichlet Allocation, the framework fills critical gaps in existing research. The analysis reveals that government financial incentives occupy the foundational layer of the ISM hierarchy and serve as a key driver of recycling behavior among restaurant operators; educational attainment enhances awareness and compliance but is moderated by structural constraints; and trust in third-party recyclers exerts a relatively limited influence. Correspondingly, H1 receives qualitative support, H2 is partially supported, and H3 gains only limited support. Building on these findings, the study proposes a multi-stakeholder governance framework that includes a “community-school-family” education system, an intelligent third-party management platform, and a government-led industrial chain to promote the formation of a closed-loop circular economy. The results demonstrate that the proposed framework not only offers actionable policy recommendations but also facilitates the adoption of sustainable practices and deepens the understanding of socio-economic and operational factors affecting WCO management, thereby providing strong support for energy and environmental sustainability.

Solutions of Minimized Agrochemicals Input in the Post Zero-Growth Era: A State-of-the-Art Analysis of the Hengduan Mountains, China

How to further reduce the input of agrochemicals after zero-growth is an important challenge faced by mountainous areas. Up to now, the combined solution for minimized agrochemicals intervention in the post zero-growth era has not been systematically analyzed globally. Here, the Hengduan Mountain regions (HMR) in China, as a case, we estimated the turning points of agrochemicals input intensities using a quadratic equation, as well as integrating policy document analysis and literature review. Results show that the occurred timeline of fertilizer and pesticide use zero-growth in 10 municipalities (prefectures) in the HMR is relatively wide, with a distribution from 2009 to 2019, illustrating that all municipalities (prefectures) have been achieved national goals ahead of 2020 deadline. Thus, the incentive of a series of national-level policies focusing on chemical fertilizers and pesticides has proven effective in achieving the zero-growth target of agrochemicals input in the HMR. However, comparison with major mountainous countries like Germany, Italy, Portugal, Romania, Austria, and Spain etc., there are clearly many opportunities for enhancement in reducing fertilizer and pesticide uses. We present a practical route to minimize agrochemicals application in the HMR through crop rotation-based agro-biodiversity solutions, organic alternative-based soil health solutions, professionalization-based precision farming solutions, smallholder farmers’ awareness-based behavior intervention solutions, conservation reserve-based zoning solutions, etc.

Bioenergy Technology and Carbon Intensity in U.S. and China: Threshold Roles of Capital Accumulation, Education and Inequality

Bioenergy technology holds significant promise for reducing carbon intensity and fostering sustainable development, yet its impact remains unclear. This article employs both a panel threshold model and a random forest model, analyzing data from the primary administrative regions in the United States and China to explore the threshold effects and regional heterogeneity of bioenergy technology on carbon intensity, where the bioenergy technology is measured using patent data. In the United States, the impact of bioenergy technology on carbon intensity initially shows a positive effect, which later turns negative as per capita capital stock increases. The technology’s inhibitory effect strengthens with higher levels of education but becomes insignificant as the Gini coefficient rises. In China, increasing per capita capital stock shifts the impact of bioenergy technology from negative to insignificant, while higher education levels enhance its inhibitory effect. The Gini coefficient, however, does not significantly affect the impact of technology. Additionally, these threshold effects exhibit notable regional variations. The study provides cross-country evidence of how institutional and structural conditions shape the carbon mitigation effects of bioenergy technology, offering practical insights for policies that combine trade facilitation, education, and inequality reduction with low-carbon energy transitions.

Book of Abstracts—The 10th International Symposium on Sturgeons (ISS10)

Human Behavioral Ecology: Opportunities for Theoretically Driven Research on Human Behavioral Variation in China

Human behavioral ecology is an evolutionary framework that attempts to understand how adaptive human behavior maps on to variation in social, cultural, and ecological environments. It emerged as a coherent framework in the United States and the U.K. in the 1980s and has flourished as an explanatory framework ever since. The concentration of HBE scholarship in English-speaking countries has led to missed opportunities to engage other partners in testing and expanding human behavioral ecological models of human behavioral and life history variation. In this review, we provide a brief review of human behavioral ecology and describe opportunities for related scholarship in the Chinese context. We introduce human behavioral ecology holistically, including its history, methodological frameworks, pet topics, and recent integration with related fields, with a special emphasis on its recent integration with Chinese social, archaeological, and life sciences scholarship. We address potential criticisms of human behavioral ecology and how to ensure a robust and careful application of human behavioral ecology principles in the study of human behavior in China, past and present. We conclude with excitement as the remarkable variation in the Chinese behavioral landscape offers unparalleled opportunities for innovative and integrative studies.

State of the Art in Wave Energy Conversion Technologies in China

This paper reviews the advancements in wave energy converter technologies in China, covering device design, performance evaluation, and system control techniques. It highlights power control technologies in wave energy conversion, including adaptive control, model predictive control, clutch control, clamp control, resistive load control, approximate optimal speed control, nonlinear control, and intelligent control methods. Through an analysis of these technologies, the study outlines the future directions and challenges in wave energy development in China, while also proposing potential pathways for optimizing the performance of wave energy conversion devices.

Integrated Habitat Assessment of a Protected Fish Species in the Upper Yangtze River, China: Connectivity and Suitability

In the context of anthropogenic climate change, dam construction, and other human activities, the biodiversity of freshwater fish is rapidly declining. The Upper Yangtze River Basin (UYRB) is a hotspot for hydropower development and is home to numerous endemic and rare freshwater fish species, most of which are on the brink of extinction. Schizothorax chongi is an endangered and protected fish species endemic to the UYRB, with significant economic and ecological value. However, the potential habitat of its wild population has not been reported, which hampers conservation efforts for this valuable species. This study utilized the Dendritic Connection Index (DCI) and Species Distribution Models (SDMs) to assess habitat connectivity in the UYRB and habitat suitability for S. chongi during the periods 1970–2000 and 2001–2020, respectively. The results show that S. chongi habitats underwent significant reduction during the 2001–2020 period, with the total length of medium and high suitability habitats decreasing by 51.7%. However, high suitability habitats in the southern section of the middle and lower Jinsha River, which is located in the upper and middle part of the UYRB, did not experience a noticeable reduction. Despite the relatively high habitat suitability maintained in the southern section of the middle and lower Jinsha River, connectivity has significantly declined. Restoring connectivity reduced by dam construction in this region is critically urgent. This study is the first to conduct a watershed-scale assessment of fish habitat integrating habitat suitability and connectivity providing valuable insights for local governments to develop specific conservation measures and plans. It can offer a valuable reference for researchers in the field of freshwater fish conservation.

Pathway Engineering of E. coli for Production of Fritschiellaxanthin and Other Carotenoids with α-Carotene Backbone and Their Singlet Oxygen-Quenching Activities

Some photosynthetic organisms are capable of biosynthesizing carotenoids (xanthophylls) with α-carotene backbone, that is, α-carotene-derived carotenoids, such as (3R,3′R,6′R)-3,3′-dihydroxy α-carotene (lutein). Except for lutein, such carotenoids are minor compounds in nature. In this study, α-carotene-derived carotenoids were produced with E. coli. To achieve this, carotenoid biosynthesis genes from the bacterium Pantoea ananatis containing the 4-β-ketolase (crtW) gene with/without the 3-β-hydroxylase (crtZ) gene, in addition to crtEBI genes, and biosynthesis genes (MpLCYb, MpLCYe, and MpCYP97C) from liverwort Marchantia polymorpha, along with the HpIDI gene, were cloned into plasmids. The transformed E. coli cells biosynthesized (3S,3′R,6′R)-3,3′-dihydroxy-4-keto-α-carotene (fritschiellaxanthin (4-ketolutein)), (3′R,6′R)-3′-hydroxy-4-keto-α-carotene (4-keto-α-cryptoxanthin), and (3′R,6′R)-3′-hydroxy-α-carotene (α-cryptoxanthin), as carotenoids that have not been produced by a heterologous microbial system so far. These carotenoids show potent singlet oxygen-quenching activity.

Developing a Climate Litigation Framework: China’s Contribution to International Environmental Law

Although “climate litigation” is not an indigenous term in China, localizing it is essential to support the development of an independent environmental legal knowledge system in China. Rooted in China’s judicial tradition, which emphasizes substantive rationality, traditional legal theories have primarily focused on environmental law. However, the contemporary practices in the rule of law have created an unclear trajectory for climate litigation. Research in this area has long been trapped in a paradigm that relies on lawsuits for ecological environmental damage compensation and environmental public interest litigation, leading to a significant disconnect between theoretical framworks and practical application. With the advancement of the "dual carbon" strategic goals—carbon peaking and carbon neutrality—it has become imperative to redefine the concept of climate litigation within the Chinese context. We need to establish a theoretical framework that aligns with the “dual carbon” objectives while providing theoretical and institutional support for climate litigation, ultimately contributing to the international discourse on climate justice. Additionally, Hong Kong’s proactive climate governance and robust ESG (Environmental, Social, and Governance) practices provide valuable insights for developing comprehensive climate litigation mechanisms. Based on this analysis, we propose concrete plans for building a climate litigation system in China, establishing a preventive relief system and a multi-source legal framework at the substantive level and developing climate judicial mechanisms for mitigation and adaptation at the procedural level.

Understanding Rural Consumer Credit Demand: Insights from China’s Household Income and Asset Structures

China’s ongoing supply-side structural reforms and the government’s strategic focus on rural revitalization catalyze a significant transformation in rural landscapes. The steady rise in rural residents’ incomes and assets, along with gradual improvements in household quality of life, is unlocking significant potential for growth and upgrades in the rural consumer market.This evolution necessitates a more diversified and sophisticated approach to financial services that is more inclusive and widespread. Despite the challenges, such as an aging population and imperfect credit systems that have limited the quality and precision of rural financial services, the analysis of household income and asset structures is vital for understanding consumption patterns and enhancing the economic vitality of rural households. Our study, based on the 2019 China Household Finance Survey data of 11,386 households and employing the Heckman two-stage model, finds that the proportions of income components and financial assets, moving in opposite directions, significantly influence the amount of consumer credit demanded, while other asset types, such as real estate, show no significant effect. The examination of income and asset diversity through the Herfindahl-Hirschman Index (HHI) demonstrates varying impacts of income and asset structures on credit demand, depending on the concentration levels of income and assets. Additionally, our analysis of heterogeneity based on the age of the household head and geographic region highlights the diverse influences on the amount of consumer credit demand, underscoring the importance of tailoring financial products and policies to meet the specific needs of rural households. These findings shed light on these dynamics and inform financial service innovations that align with the needs of rural consumers, thereby supporting the broader objectives of rural economic development and the achievement of China’s rural revitalization strategies.