Coherent Sub-Nanometer Interface between Crystalline and Amorphous Materials Boosts Electrochemical Synthesis of Hydrogen Peroxide.

There are enormous yet largely underexplored exotic phenomena and properties emerging from interfaces constructed by diverse types of components that may differ in composition, shape, or crystal structure. It remains poorly understood the unique properties a coherent interface between crystalline and amorphous materials may evoke, and there lacks a general strategy to fabricate such interfaces. It is demonstrated that by topotactic partial oxidation heterostructures composed of coherently registered crystalline and amorphous materials can be constructed. As a proof-of-concept study, heterostructures consisting of crystalline P3 N5 and amorphous P3 N5 Ox can be synthesized by creating amorphous P3 N5 Ox from crystalline P3 N5 without interrupting the covalent bonding across the coherent interface. The heterostructure is dictated by nanometer-sized short-range-ordered P3 N5 domains enclosed by amorphous P3 N5 Ox matrix, which entails simultaneously fast charge transfer across the interface and bicomponent synergistic effect in catalysis. Such a P3 N5 /P3 N5 Ox heterostructure attains an optimal adsorption energy for *OOH intermediates and exhibits superior electrocatalytic performance toward H2 O2 production by adopting a selectivity of 96.68% at 0.4 VRHE and a production rate of 321.5 mmol h-1 gcatalyst -1 at -0.3 VRHE . The current study provides new insights into the synthetic strategy, chemical structure, and catalytic property of a sub-nanometer coherent interface formed between crystalline and amorphous materials.

Do COVID-19 pandemic-related policy shocks flatten the bid-rent curve? Evidence from real estate markets in Shanghai.

The COVID-19 pandemic has drastically affected the socioeconomic activities and peoples' daily life, resulting in a change in locational preferences in the real estate markets. Although enormous efforts have been devoted to examining the housing price impacts of the COVID-19 pandemic, little is known about the responses of the real estate markets to the evolving pandemic control measures. This study investigates the price gradient effects of various pandemic-related policy shocks using a hedonic price model on the district-level property transaction data in Shanghai, China over a 48-month period from 2018 to 2021. We found that these shocks have significantly altered the bid-rent curves. The price gradient for residential property units decreased in absolute value to - 0.433 after Wuhan's lockdown, demonstrating peoples' preferences to avoid the high infection risks in districts closer to the city center. However, in the post-reopening and post-vaccine periods, the price gradient increased to - 0.463 and - 0.486, respectively, implying rational expectations of a recovering real estate market for the low infection and mortality rates. In addition, we discovered that Wuhan's lockdown has steepened the price gradient for commercial property units, suggesting a decline in business volumes and an increase in operating costs in the low-density districts imposed by the strict pandemic control measures. This study contributes to the empirical literature on the price gradient effects of the COVID-19 pandemic by extending the study period to the post-vaccine era.

Oxygen vacancies on Nb2O5 enhanced the performance of H2O2 electrosynthesis from O2 reduction.

A serial oxygen vacancy (OV) on Nb2O5 is synthesised by H2 calcination, and H-300 exhibited high selectivity and activity for H2O2 (93.4%, 562.5 mmol gcat-1). A volcano relationship is identified between the OV content and performance, which provides an attractive insight into designing electrocatalysts.

A Path Analysis of the Effect of Neighborhood Built Environment on Public Health of Older Adults: A Hong Kong Study.

Introduction: Health deterioration among frail older adults is a public health concern. Among the multi-dimensional factors, the neighborhood built environment is crucial for one's health. Although the relationship between the built environment and health in the general population has been thoroughly investigated, it has been ignored in the case of frail older adults, who may have difficulties in their daily basic living skills. A path analysis is constructed to model the proposed theoretical framework involving the neighborhood built environment and health among frail older adults. This study thus aims to investigate the environmental influences on health, and to validate the theoretical framework proposed for health and social services. Methods: This study used secondary data collected in Hong Kong. A sample of 969 older community dwellers aged 60 or above were frail with at least one activity of daily living. Demographic information, neighborhood built environment data, service utilization, and health conditions were collected from these participants and their caregivers. A path analysis was performed to examine the proposed theoretical framework. Results: The health condition was of general concern, including frailty and incapacities in daily activities in frail older adults. Besides psychosocial factors, service use, and caregivers' care quality, the built environment had a significant impact on the health of older adults as well. Specifically, more facilities offering services and groceries, a shorter distance to the nearest metro station, and more greenery exposure are associated with a better-expected health condition among frail older adults. Discussion: The proposed theoretical framework successfully supplements past negligence on the relationship between the built environment and the health of frail older adults. The findings further imply that policymakers should promote the usability of transit and greenery in neighborhoods and communities. In addition, service utilization should be improved to meet the basic needs of frail older adults in the communities.

Tackling the "last mile" problem in renovation waste management: A case study in China.

Solid waste generated from building renovation, called "renovation waste" in this study, represents a major waste management problem. A particular difficulty is sourcing renovation waste arising sporadically from discrete sites for central processing. This can be characterized as a "last mile" problem in renovation waste management (RWM). This study reports good practice for dealing with the RWM last mile problem in a city in China. We conduct qualitative research comprising site investigations and interviews, organized in an in-depth case study. We discover that the city effectively solved the last mile problem by developing a multi-layer, nested waste management system, empowered further by various smart technologies and concerted collaboration from multi-stakeholders coordinated by a determined government. Nevertheless, the longevity of the RWM is contingent on confronting several challenges, including (a) achieving cost and benefit balance, (b) defining clearer standards and policies, and (c) raising stakeholders' awareness of waste management. A general RWM strategy is recommended to establish fluent channels through which to source and qualify renovation waste for central treatment. The study delves into the much neglected world of RWM and provides a valuable reference for tackling similar problems.

Estimating construction waste generation in the Greater Bay Area, China using machine learning.

Reliable construction waste generation data is a prerequisite for any evidence-based waste management effort, but such data remains scarce in many developing economies owing to their rudimentary recording systems. By referring to several models proposed for estimating waste generation, this study aims to develop a reliable and accessible method for estimating construction waste generation based on limited publicly available data. The study has two objectives. Firstly, it aims to estimate construction waste generation by focusing on the Greater Bay Area (GBA) in China, one of the world's most thriving regions in terms of construction activities. Secondly, it aims to compare the strengths and weaknesses of various waste quantification models. 43 sets of annual socio-economic, construction-related and C&D waste generation data ranging from 2005 to 2019 were collected from the local government authorities. By analyzing the data using four types of machine learning models, namely multiple linear regression, decision tree, grey models, and artificial neural network, it is found that all calibrated models, with their respective strengths and weaknesses, can produce acceptable results with the testing R2 ranging from 0.756 to 0.977. This study also reveals that the 11 cities in the GBA produced a total of about 364 million m3 of construction waste in 2018. The result can be used for monitoring the urban metabolism, quantifying carbon emission, developing a circular economy, valorizing recycled materials, and strategic planning of waste management facilities in the GBA. The research findings also contribute to the methodologies for estimating waste generation using limited data.

An analytical framework of "zero waste construction site": Two case studies of Shenzhen, China.

Around the global construction industry, there is an emerging trend to pursue a "zero-waste" goal at the site level, but little is known about it. This paper aims to shed insights on the waste management concept of "zero waste construction site" by delineating its meaning, system boundary, assessment period, and operation strategies, which are further formulated in an analytical framework. Owing to the nascent nature of the concept, we adopted a qualitative approach including archival study, a series of semi-structured interviews, and two in-depth case studies in Shenzhen, China to sketch the analytical framework. Meanwhile, an analogy between "zero waste construction site" and "net zero building" is continuously made to fine-tune and finalize the framework. This research demonstrates that the zero-waste goal is challenging but achievable on individual construction sites. The system boundary to examine the zero-waste goal is contingent on the project scope, be it a new construction, renovation, or demolition project. The assessment period is dependent on the duration of the construction project. However, it would be too costly, if not entirely impossible, to achieve a "zero waste construction site" by treating it as a closed system. Rather, one needs to consider open, off-site strategies, e.g., engaging third-party recycling services, reusing recycled materials in subsequent projects, or trading it in to a recycled material market. The analytical framework can be utilized to scrutinize existing construction waste management practices. In the long term, the research will contribute positively to a "zero waste" society.

A four-quadrant conceptual framework for analyzing extended producer responsibility in offshore prefabrication construction.

Prefabrication has been widely advocated as a green production strategy to minimize the adverse environmental impacts of construction. Amid economic globalization, prefabricated construction materials are commonly sourced offsite and even offshore. As an issue emerging alongside offshore prefabrication, extended producer responsibility (EPR) is yet to be clearly identified, allocated, and implemented. This research develops a conceptual framework using a design thinking process, through which EPR associated with offshore prefabrication can be analyzed, agreed upon, and allocated. By considering the scope and scale of the responsibility and the procurement methods, the framework comprises four quadrants representing four typical scenarios for implementation of the EPR principle. It is applicable for both short-term and lifelong EPR analysis, in both traditional and integrated project delivery contexts. The framework will be particularly useful for devising public policies to achieve an onshore and offshore stakeholder win-win situation.

University Students' Purchase Intention and Willingness to Pay for Carbon-Labeled Food Products: A Purchase Decision-Making Experiment.

Carbon labeling describes carbon dioxide emissions across food lifecycles, contributing to enhancing consumers' low-carbon awareness and promoting low-carbon consumption behaviors. In a departure from the existing literature on carbon labeling that heavily relies on interviews or questionnaire surveys, this study forms a hybrid of an auction experiment and a consumption experiment to observe university students' purchase intention and willingness to pay for a carbon-labeled food product. In this study, students from a university in a city (Chengdu) of China, the largest carbon emitter, are taken as the experimental group, and cow's milk is selected as the experimental food product. The main findings of this study are summarized as follows: (1) the purchase of carbon-labeled milk products is primarily influenced by price; (2) the willingness to pay for carbon-labeled milk products primarily depends on the premium; and (3) the students are willing to accept a maximum price premium of 3.2%. This study further offers suggestions to promote the formation of China's carbon product-labeling system and the marketization of carbon-labeled products and consequently facilitate low-carbon consumption in China.

Implementing on-site construction waste recycling in Hong Kong: Barriers and facilitators.

Construction and demolition (C&D) waste recycling constitutes an indispensable component in the overall waste management strategy. Unlike the traditional recycling approaches whereby C&D waste is transported to off-site facilities for treatment, construction managers are actively exploring the possibility of on-site recycling where C&D waste is treated directly at source. This study reports the barriers and facilitators of implementing on-site C&D waste recycling by contextualizing it in Hong Kong. It does so by adopting a mixed-method approach combining case study, site visits, and interviews. It is discovered that the barriers include (1) site space constraints, (2) narrow window of opportunity to trade recycled products, (3) vulnerable business case, (4) lack of support from off-site recycling, and (5) lack of government policy support. A series of facilitating measures are also proposed, including (1) developing customized on-site recycling equipment, (2) establishing a demand-supply information-sharing platform, (3) developing more thriving off-site recycling, and (4) providing more government support. This study probes into the real-life on- and off-site waste recycling practices in Hong Kong's prominent C&D management system. It can also provide useful references for others in developing their own C&D waste recycling strategies by rationally deploying on- and off-site recycling.

Developing efficient circularity for construction and demolition waste management in fast emerging economies: Lessons learned from Shenzhen, China.

Proper management of construction and demolition (C&D) waste is a key challenge amid global advocacy of the circular economy. This is of particular urgency in fast-emerging economies, where economic development induces massive construction without the capacity to manage the associated waste. This paper reports lessons learned from Shenzhen, China, which has witnessed exciting economic growth in the past few decades but also been compelled to rapidly develop an effective C&D waste circular economy from a low base. The research adopts a mixed-method approach combining case study, site investigations, and interviews in Shenzhen. It is discovered that Shenzhen's success can be attributed to (a) implementing strong governmental interventions; (b) developing a thriving C&D waste recycling market; (c) introducing advanced recycling technologies; and (d) enacting responsive institutional arrangements. Further improvements related to (1) recycled product certification, (2) land use and economic subsidies, and (3) changing circular economy philosophies, inter alia, are desired to sustain the long-term prosperity of this circular economy. The research provides a reference which can be adapted to the unique context of other emerging economies in developing effective circularity.

Procurement innovation for a circular economy of construction and demolition waste: Lessons learnt from Suzhou, China.

Amidst the global trend of advocating a circular economy, various nations and regions in recent years have started to explore innovative procurement models (e.g., Public Private Partnership [PPP]) in dealing with beset issues related to construction and demolition (C&D) waste. However, PPP is suffering from problems such as 'long negotiation time', 'lack of transparency', and 'uneven risk and return allocation', which in turn lead to 'ineffective delivery' and 'poor value for money'. Using a case study, this paper reports some lessons learnt from innovative practices of procuring C&D management services in Suzhou, China. It is discovered that the public and private sectors, without prior knowledge, are operating based on a general concession framework instead of negotiating a clear-cut agreement from the outset. Several key arrangements, such as price, concession period, and strategic operations, are based on relational contract-type of agreements, which are found particularly innovative for shortening the negotiation time, fostering the trust between the relevant parties, dealing with emerging ad hoc problems, and allowing sustainable development of the circular economy. To make such PPP work, it is critical to devise institutions to prevent corruption and opportunistic behaviors. This research provides useful references to developing a circular economy. Although they focus on C&D waste management, the research findings can be applied to other public procurement settings, such as municipal solid waste management service.