Enhanced Goos-Hänchen shift in a defective Pell quasiperiodic photonic crystal with monolayer MoS2.

Monolayer M o S 2 has attracted wide attention because of its finite bandgap, and it has become a potential candidate for the investigation of the Goos-Hänchen (GH) shift. However, the magnitude of the GH shift in free-standing monolayer M o S 2 is small, which greatly hinders its possible applications in the photoelectric sensors and detectors. We have theoretically designed a defective quasiperiodic photonic crystal and investigated its GH shift, where monolayer M o S 2 is sandwiched between two quasiperiodic photonic crystals arranged by the Pell sequence. By optimizing the thicknesses of all the components and the period number of the Pell quasiperiodic photonic crystal, we find that the GH shift of the designed structure is significantly enhanced at the specific working wavelength. In addition, we discuss the influence of the thicknesses of the dielectric components on the GH shift. Our work confirms that the quasiperiodic photonic crystal structure has the ability to enhance the GH shift of monolayer transition metal dichalcogenides, which provides a new platform for the GH investigations and greatly promotes the applications of this defective structure in optoelectric devices.

Assessing the implementation effect of Shanghai's compulsory municipal solid waste classification policy.

Waste treatment is a problem faced by cities all over the world. In recent years, China, as a developing country, regards the municipal solid waste (MSW) classification as one of the important strategies to deal with the MSW problem. The previous MSW classification policies in China were all only advocacy in nature. It was not until January 2019 that the "Regulations on the Management of MSW in Shanghai" was officially promulgated as China's first compulsory MSW classification policy, marking the beginning of an era of compulsory MSW classification in China. How effective is the implementation of Shanghai's compulsory MSW classification policy 18 months after its implementation and can developing countries continuously and effectively implement compulsory MSW classification policies? These are important issues of concern to the government, academia, and the public. This paper establishes a three-stage DEA model to evaluate the implementation effect of the compulsory MSW classification policies in Shanghai during the period of February 2019 and July 2020. The study found that the average efficiency of the compulsory MSW classification policy in Shanghai reached 0.906 during the study period, indicating that the policy was executed reasonably well. However, there are only 5 months in 18 months that the policy was fully effective (reaching efficiency level 1), suggesting that there is still room for improvement. The main reason for not being able to achieve full effectiveness in some months is attributed to scale efficiency. At the same time, the general public budget revenue and expenditure of environmental variables have positive and negative impacts on the policy implementation effect in Shanghai. The research results can provide experience for China to comprehensively implement the compulsory MSW classification policy in the future and can also provide valuable case study information for cities in other developing countries to implement the compulsory MSW classification policy.

Evaluating the efficiency of municipal solid waste collection and disposal in the Yangtze River Delta of China: A DEA-model.

As the "sixth largest city group in the world", the Yangtze River Delta region is an important economic growth point and core economic area in China. While achieving rapid economic growth, the amount of waste generated is increasing day by day, and the investment in environmental protection is constantly increasing. Among them, MSW collection and disposal funds accounted for 57.40% of the fixed assets investment in environmental sanitation in 2017. To improve the efficiency of existing environmental protection investment, this paper is based on the existing academic research at China and abroad, with the help of the Data Envelopment Analysis (DEA) model. This paper analyzed the economic indicators of 27 cities in the Yangtze River Delta for MSW collection, transportation and disposal to measure economic efficiency, identify and improve inefficiencies. The research results show that the average efficiency of the 27 cities in the Yangtze River Delta is at a relatively high level. Six cities have the most effective comprehensive technical efficiency. These six cities constitute the effective frontier of the municipal solid waste transfer system. The overall efficiency has a comparative advantage; 9 cities have the best pure technical efficiency, accounting for 33 of all cities. %, the pure technical efficiency of the remaining 18 cities is low, indicating that these cities have not fully utilized their resource input under the current scale, and the efficiency of resource utilization needs to be improved. Finally, this paper proposes suggestions for improvement from the perspective of environmental sustainability. To improve MSW collection and disposal efficiency, differentiated management should be implemented in cities in the Yangtze River Delta.Implications: This paper conducts an empirical analysis on the efficiency of MSW collection and disposal in the Yangtze River Delta in China in 2017. Based on the calculation of the DEA model, our conclusion is that although the collection and disposal system of MSW in the Yangtze River Delta has been significantly improved, the level of collection and disposal of some MSW has not reached the optimal level: (1) Comprehensive technical efficiency is the most effective Cities accounted for 22% of the total number of cities studied. (2) 33% of the cities in the Yangtze River Delta achieve the best pure technical efficiency; (3) Among the 27 cities, 6 cities have the best scale efficiency, and the remaining 21 cities have not reached the best scale efficiency.

The potential value of recycling municipal household solid waste in Shanghai, China.

The recycling of municipal household solid waste (MHSW) is important for the environmental preservation and wellbeing of the society. In recent decades, continuous efforts in research, policy-making and municipal administration have led to improvements toward more sustainable MHSW recycling. However, MHSW recycling remains a major challenge for China. This paper analyzes the current value and potential value of MHSW recycling in order to guide residents to recycle MHSW effectively and to reduce the amount of recycle-worthy materials missing recycling. A multivariate probit model is developed to ascertain the current value and potential value of MHSW recycling. Results from a case study of Shanghai reveal that waste glass has low current value and low potential value, and waste plastics has low current value but high potential value. The results also indicate that the waste metal has high current value and high potential value, whereas waste paper has high current value but low potential value. These findings provide policymakers with useful information and rationale for directing efforts to achieve a better or optimal MHSW recycling practice.Implications: Be a multivariate probit model is developed to calculate the current value and potential value of MHSW recycling in order to guide residents to recycle MHSW and reduce an amount of miss-recycling materials. Our results have shown that waste glass has a low current value and a low potential value, waste plastics have a low current value and a high potential value. Regarding the waste metal, they have a high current value and a high potential value. For waste papers, the result indicates that it has a high current value and a low potential value.

A stochastic frontier analysis of the efficiency of municipal solid waste collection services in China.

Governments in many developing countries, such as China, are investing a lot of human, financial and material resources to ensure that as much of municipal solid waste (MSW) as possible is collected for centralized harmless treatment and disposal. This is regarded as an effective way to alleviate the "waste siege" problem in governance caused by the continuous enormous increase in MSW quantity. Therefore, how to improve the efficiency of MSW collection service system is an important governance issue because the inputs that can be utilized to manage MSW problem are limited due to budget and resource constraints. However, studies on MSW collection efficiency in developing countries like China are under-represented in the existing literature. This paper applies a stochastic frontier analysis (SFA) approach to evaluate the efficiency of MSW collection services in 30 provinces of China from 2008 to 2017, and explore the relative importance of several factors that might influence collection efficiency. The results indicate that there exists considerable room (62.8%) to enhance efficiency since its current efficiency value is merely 0.372. With regard to influencing factors, the proportion of population aged 15-64 appears to have the greatest positive impact on efficiency, along with per capita GDP, added value of tertiary industry and education level. This paper also explores spatial variations of MSW collection efficiency across the eastern, central and western regions. These findings have policy implications and can inform the related government departments how to formulate proper policies to improve collection efficiency.

Predicting the implementation effect of the municipal solid waste mandatory classification policy based on the residents' behavior.

The rapid development of China's economy has led to a sharp increase in the municipal solid waste (MSW). China has promulgated the MSW mandatory classification policy. The implementation effect of such mandatory policy is an important concern to the government, scholars, and the public, but has not been extensively studied. This paper explores the implementation effect of such policy through assessing the waste classification behavior of residents based on the Cellular Automata model. The simulation results show that the residents will not adjust their MSW classification behavior during the time period when the mandatory classification policy is not implemented. But when the mandatory classification policy is imposed, the residents will adjust their classification behavior over time from t = 100 to t = 300. The results indicate that the extent of residents' participation in waste classification varies by different enforcement intensities. The higher the intensity is, the more rapidly the residents' MSW classification behavior improves. The results also indicate that the extent of residents' participation in waste classification varies by different urban population size. The larger the urban population size is, the higher the proportion of classification participation is. Implications: The implementation effect of the municipal solid waste mandatory classification policy is an important concern to the government, scholars, and the public, but has not been extensively studied. This paper explores the implementation effect of such policy through assessing the waste classification behavior of residents based on the Cellular Automata model. The simulation results show that the residents will not adjust their municipal solid waste classification behavior during the time period when the mandatory classification policy is not implemented. But when the mandatory classification policy is imposed, the residents will adjust their classification behavior over time. The results also indicate that the extent of residents' participation in waste classification varies by different enforcement intensities and different urban population sizes.

Charging for municipal solid waste disposal in Beijing.

Considering the various ways of Municipal Solid Waste (MSW) disposal that are currently in practice, this paper proposes a bundle pricing model of MSW disposal in Beijing, China. The bundle pricing model is set according to per capita annual disposable income, per capita annual consumption expenditure and MSW disposal cost based on the cost reimbursement principle and complementarity principle. This paper first estimates the unit costs of landfill and incineration respectively, and then designs three bundling packages according to three different income levels of households in Beijing (low-income households, middle-income households and high-income households). Specifically, based on our bundle pricing model, we propose to charge low-income households (of the average size of 3 persons) MSW fees 5.64 RMB per month, middle-income households 10.16 RMB, and high-income households 20.70 RMB per month. We also discuss and explain how the proposed mechanism can be expected to not only mitigate the capital shortage problem, but also reduce MSW quantity and improve the MSW incineration disposal technology.

The policy-making trend analysis of municipal solid waste in China 1980-2015.

Over the past 35 years, the Chinese government has established various policies to tackle problems related to the municipal handling of solid waste. It is necessary to study policy-making trends in the area of municipal solid waste for further sustainable development in China. This article fills this gap by designing a new analytical framework made up of policymaker indicators, policy practitioner indicators, policy beneficiaries' indicators, policy tool indicators, and policy support indicators in order to analyse the policy-making trend based on China's major municipal solid waste policies from 1 January 1980 to 1 March 2015. Results have shown that policy-making related to municipal solid waste has changed significantly in the past 35 years and that more municipal solid waste policies were issued by one or a few ministerial departments than by the State Council and National People's Congress. Moreover, the study has shown that the government and companies have dedicated more attention to taking action about municipal solid waste than individuals. With regard to the policy tools, policy-making has stressed the use of market-type tools, regulation-type tools, and public participation-type tools together to tackle the municipal solid waste problem since 2000. Finance and information support were used more as policy support by municipal solid waste policies than technology. This article provides some novel insights on the policy-making trend of municipal solid waste in China.

Quantitative evaluation of heavy metals' pollution hazards and estimation of heavy metals' environmental costs in leachate during food waste composting.

Heavy metals in leachate during food waste composting may produce different degrees of pollution hazards and further induce environment costs, when the concentrations of heavy metals exceed the discharging quality standards. Quantitative evaluation of heavy metals' pollution hazards and estimation of such environmental costs are under-represented in the existing literature. This paper uses a logistic function approach to evaluate the extent of pollution hazards of heavy metals such as cadmium (Cd), chromium (Cr), mercury (Hg), lead (Pb) and arsenic (As) and to estimate heavy metals' environmental costs in leachate during food waste composting from Minhang food waste treatment plant located in northern Shanghai, China. Major findings of this study are: (1) The pollution hazards rate of Cd amounts to 94.03%, probably because Cd-containing materials such as plastics are mixed with food waste; (2) With the comprehensive pollution hazards rate estimated as 94.48%, the environmental costs caused by heavy metals in leachate during food waste composting amount to US$0.52 per tonne. This magnitude of environmental costs is meaningful and significant, considering that it is equivalent to 2.97% of Shanghai's food waste treatment charges.

Evaluation of optional fee structures for solid waste management in China.

A municipal solid waste fee has become an important means for the implementation of the waste management rendered by the government all around the world. Based on the ecological environmental compensation theory, this article constructs an analytical framework of waste charging from the perspective of public policy evaluation, to carry on the comprehensive comparison and analysis to the operability, feasibility, validity, rationality, and universality of the two modes of waste charging: Ration charge and unit-pricing modes. The results indicate that in the cities with large amounts of waste production, long time of waste charging, and high disposal rate, pilot projects should be carried out; and the government needs to improve the construction of associated laws and regulations.

Municipal household solid waste fee based on an increasing block pricing model in Beijing, China.

This article aims to design an increasing block pricing model to estimate the waste fee with the consideration of the goals and principles of municipal household solid waste pricing. The increasing block pricing model is based on the main consideration of the per capita disposable income of urban residents, household consumption expenditure, production rate of waste disposal industry, and inflation rate. The empirical analysis is based on survey data of 5000 households in Beijing, China. The results indicate that the current uniform price of waste disposal is set too high for low-income people, and waste fees to the household disposable income or total household spending ratio are too low for the medium- and high-income families. An increasing block pricing model can prevent this kind of situation, and not only solve the problem of lack of funds, but also enhance the residents' awareness of environmental protection. A comparative study based on the grey system model is made by having a preliminary forecast for the waste emissions reduction effect of the pay-as-you-throw programme in the next 5 years of Beijing, China. The results show that the effect of the pay-as-you-throw programme is not only to promote the energy conservation and emissions reduction, but also giving a further improvement of the environmental quality.