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Thin-wall diamond trepanning bits are extensively used for processing hard and brittle materials such as engineering ceramics. However, it is difficult to achieve high-efficiency processing of engineering ceramics at a constant feed speed, because of high dynamic compressive strength, high hardness, and low density of engineering ceramics. In this study, a novel composite diamond bit combining sintering and brazing has been designed, along with the low-frequency axial vibration technology, to realize the continuous hole processing of engineering ceramics. Drilling experiments have been conducted on Al 2 O 3 and SiC engineering ceramics with a constant feed speed. The variation of axial force, micromorphology of hole wall surface drilled, as well as the method of removing nesting during the drilling process were analyzed. According to the results, the novel composite diamond bit fabricated by combining sintering and brazing, can achieve the continuous hole processing of engineering ceramics at a constant feed speed, including Al 2 O 3 and SiC. Compared to the conventional drilling (CD), the low-frequency axial vibration drilling (LFVD) can significantly reduce the axial force, and produce fewer plastic scratches on the hole wall surface drilled. In particular, the automatic blanking ratio approaches to 100% by LFVD, and only about 73.58% by CD. It can be concluded that LFVD technology can be used to realize continuous hole processing of engineering ceramics. The research results achieved in this study show that the drilling machinability of engineering ceramics by LFVD and novel composite diamond bit is good. Accordingly, this study provides a useful reference for continuous processing or batch production of engineering ceramics at a constant feed speed. [ABSTRACT FROM AUTHOR]

Abstract High purity engineering ceramics have been increasingly used for constituting novel lightweight ceramic composite armors along with various FRP materials. In the assembly process of ceramic composite armors, a large number of hole processing is required. Usually, diamond trepanning drills are preferentially adopted for machining relatively large holes of engineering ceramics. However, during drilling high purity armor engineering ceramics, the diamond tools are usually worn considerably due to their high dynamic compression strength and high hardness. In this study, taking the high purity alumina armor ceramics (99 wt% Al 2 O 3) as machining object, the comprehensive wear features of the sintered diamond trepanning drill have been intensively studied through SEM examinations, including the microscopic wear morphologies of diamond grains and matrix binding agent, the diamond abrasion mechanism, the wear disfigurations of the drill labial surface and the drill slipping mechanism. According to the discussed results, the wear process of the diamond grains at the matrix labial surface can be divided into three stages: intact crystal, slight wear and severe wear stages. The quicksand phenomenon occurrence around the diamond grains is the typical feature of the matrix binding agent wear. The normal grinding of the drill can be interrupted by the severe inner-trumpet-shape wear and the cutting-groove wear of the drill labial surface. In most situations, only the slight inner-trumpet-shape wear occurs for the drill, which does not affect the normal drilling operation. The drill slipping is mainly attributed to the fact that most exposed diamond grains at the drill labial surface have been rubbed down into a polished planar shape and totally blunted. The results achieved in this study can provide helpful references for the performance improvement design of the sintered diamond trepanning drill. [ABSTRACT FROM AUTHOR]

To mirror an important aspect of ultra-high voltage network development, the remarkable amount of energy cost and carbon emissions of a typical ultra-high voltage transformer substation in China is revealed, in light of the hybrid method as the integration of input-output analysis and process analysis. By inclusively inventorying all the input items as products of the economy, the study differs from previous studies that simply treat the input items as some primary materials. The results show that the total energy cost and carbon emissions of 1000 kV transformer substation are 6.82E+09 MJ and 7.12E+05 t CO 2 eq., respectively. Equipment purchasing contributes more than 80% to the overall energy cost and carbon emissions, followed by construction engineering, additional service and installation engineering. From the sectoral perspective, Manufacture of equipment for power transmission and distribution and control sector (Sector 78) dominates the energy cost and carbon emissions induced by 1000 kV transformer substation, followed by Construction industry (Sector 95). The comparison and analysis between current research and previous studies in different countries and different voltages is clearly discussed. This study not only enhances our understanding about the impact of ultra-high voltage network on energy and environment, but also provides insights for energy conservation and low carbon development. [ABSTRACT FROM AUTHOR]

Rapid urbanization drives the expansion of urban power girds, which involves enormous energy intensive products such as steel and concrete and inevitably results in a great quantity of carbon emissions. However, little has been done to investigate urban power girds' impact on carbon emissions. To solve this problem, this study makes efforts to calculate the carbon emissions of urban power grid in Jing-Jin-Ji region, one of the most populous and economically dynamic regions in China, in light of the hybrid method. Moreover, the depreciation life of urban power grids is taken into consideration for the first time, which avoids the underestimation of the accumulated carbon emissions of urban power grid due to depreciation. The results show that the accumulated carbon emissions of urban power grid in Jing-Jin-Ji region are 2.71E+06 t CO 2 eq. in 1993. When it comes to 2014, this figure increases by over 7.2 times. The majority of the carbon emissions by typical urban substations and transmission line projects are contributed by electrical equipment, steel and construction industries. 4 scenarios are set to predict the future carbon emissions by power grids in Jing-Jin-Ji region. The highest accumulated carbon emissions in 2020 are projected to be 7.63E+07 t CO 2 eq. under the condition shortest depreciation life (SDL) in the First Year Finished (FYF) scenario. Regression analysis is also carried out to show some influential factors such GDP's influence on power grids' carbon emissions, suggesting that the correlation between carbon emissions and regional economic development becomes more significant after Power System Reform Plan in 2002. This study not only draws a holistic picture of power grid but also bears significance to policies and actions in urban regions. [ABSTRACT FROM AUTHOR]

Rapid urbanization has had many negative impacts on China's coastal waters. Based on the seawater EKC, we analyse the evolution of seawater quality in China's mainland coastal waters. We explore the specific urbanization factors affecting seawater quality in coastal waters via multiple panel regression analysis. China's coastal seawater environment is improving. The proportion of Class I and Class II seawater in China's coastal waters fluctuates while inferior Class IV seawater decreases. The proportion of good-quality seawater in China's coastal waters is mainly affected by the population urbanization rate and per capita gross domestic product (GDP). In contrast, the proportion of poor-quality seawater in China's coastal waters is mainly affected by land urbanization, non-agriculturalization, and per capita GDP. Various dimensions of urbanization have different impacts on seawater quality in China's coastal waters at middle and high urbanization levels. The population urbanization rate increases the proportion of poor-quality seawater at the moderate urbanization level and inhibits it at the high urbanization level; the land urbanization rate has reverse effects. [ABSTRACT FROM AUTHOR]

Electricity-related carbon emissions in a specific region can vary significantly as the scope for emissions accounting changes. Existing studies have mainly focused on carbon emissions caused by local power generation (Scope 1) and carbon emissions embodied in the electricity consumed by a region after cross-regional electricity transmission (Scope 2). Previous studies have ignored the electricity-related carbon emissions induced by regional consumption (Scope 3), leading to carbon emissions leakage. Comprehensively employing the IPCC emissions accounting method, a network approach that simulates cross-regional electricity flow and an environmentally extended input-output model, this study provides systematic electricity-related carbon emissions accounting for regional electricity-related carbon emissions under Scopes 1, 2 and 3 using the case of Shanghai in the period of 2007–2012. The results show that Shanghai has large net inflows of electricity-related carbon emissions through power grids and regional trade, causing Scope 2 and Scope 3 emissions to be significantly larger than Scope 1 emissions in Shanghai. A Logarithmic Mean Divisia Index (LMDI) model is used to analyze the driving factors of carbon emissions under Scope 1, and the driving factors of carbon emissions under Scopes 2 and 3 are evaluated using structural decomposition analysis (SDA). Fuel structure improvement can help to reduce Shanghai's Scope 1 emission, while the power generation volume increase has opposite effect. Power transmission structure and power transmission scale decrease Shanghai's Scope 2 emissions, while the power consumption scale is positive with emission growth. The declining carbon emissions intensity and improving electricity efficiency offset the growth of Shanghai's Scope 3 emissions, while the increase in population and per capita electricity consumption contribute to the increase in Scope 3 emissions. This study could help to enhance the understanding of regional electricity-related carbon emissions and to support comprehensive and systemic carbon mitigation strategies. [ABSTRACT FROM AUTHOR]

Niobium has been classified as one critical metal due to its wide applications in both fundamental and strategic industries. However, niobium resource is limited and unevenly distributed. China is the biggest niobium consumer and the demand for niobium will continue to increase due to its rapid urbanization and industrial development. This study aims to uncover the key features of niobium metabolism in China during 2000–2021 by employing a dynamic material flow analysis method. Our results show that both niobium flows and stocks experienced fast growth in China and the domestic demand for finished niobium products was highly concentrated. Moreover, China mainly relied on importing primary niobium resources from Brazil and Canada, while exporting semi-finished niobium products to Korea, Vietnam, Indonesia, and India. Several policies are then proposed by considering the Chinese realities to improve the utilization efficiency of niobium resources and secure its sustainable supply. [Display omitted] • China's total niobium flows and stocks increased greatly from 2000 to 2021. • Domestic demand for finished niobium products in China is highly concentrated. • China heavily relied on importing primary niobium products. • China exported a huge amount of semi-finished niobium products. [ABSTRACT FROM AUTHOR]

The differentiated research of energy consumption has important practical and theoretical significance. For this purpose, this paper constructs a differentiated energy Kuznets curve (EKC) and a Cobb-Douglas production function based on provincial time series data to analyse the evolution of the influential mechanism on mainland China's economic development. Mainland China's energy intensity first increases and then decreases and shows an asymmetric inverted U-shaped curve. There are also significant differences in various provinces' EKC s. The starting points, inflection points and evolution trajectories of these EKC s are different among mainland China's provinces. When the economic level at the inflection point is higher, the energy intensity will be lower. The reason for these differences in various provinces' EKC s is that the unit energy consumption variation (UE) and the total energy consumption increase value (TE) in various Class production functions are different. Specifically, the contribution of energy input and technical progress to economic development is significant, while energy consumption is still the factor that drives economic development in most of mainland China's provinces. • Energy consumption patterns form the differentiated EKC s in mainland China's provinces. • Energy consumption is still the dominant factor driving mainland China's economic development. • Technical progress will become the main driving force for socioeconomic development. [ABSTRACT FROM AUTHOR]

• A unified framework is developed to track water use in China's energy supply chain. • Direct water withdrawal and its drivers of China's energy sectors are revealed. • Top imports/exports of water embodied in China's energy trade are analyzed. • Strategies from energy supply, demand and international trade sides are proposed. It's anticipated that future expansion of energy industry in China will inevitably exert enormous pressure on water use both at home and abroad, due to the globalized energy supply chains. Therefore, this study aims to systematically evaluate the global water use embodied in China's energy supply chains (i.e., energy supply, demand and international trade) in a unified framework by using a global multi-regional input-output analysis. The results reveal that China's direct water withdrawal by energy sectors (i.e., coal, oil, gas, petroleum and electricity) amounts to 117 billion m3 in 2011, of which foreign demand mainly from USA, EU28 and Japan drives one quarter. From energy demand side, only water roughly equivalent to one fifth of direct water withdrawal of energy sectors is embodied in China's final demand of energy sectors, indicating that energy sectors transfer large amounts of water embodied in intermediate use to downstream sectors. Regarding water use embodied in China's energy trade, China mainly imports from XSU (Rest of Former Soviet Union), Russia and Korea, and exports to Vietnam, Singapore and XEA (Rest of East Asia). Although much of the discussion around China's energy-water nexus is focused on local perspective, our findings highlight the importance to consider the impacts of China's globalized energy supply chains on worldwide water use when formulating policy. [ABSTRACT FROM AUTHOR]

Abstract This paper builds an environmental Kuznets curve (EKC) multiple logistic regression model to analyze how socio-economic development impacts mainland China's coastal waters environment. China's coastal provinces have significantly different seawater quality at different stages of the seawater's EKC. Jiangsu and Hebei are still at the early stage of the seawater's EKC because of the large quantity of pollution-intensive industry, whereas the coastal provinces at the late stage of the seawater's EKC have presented obviously improved seawater quality based on adjustments in the industrial structure since 2001. Urbanization has a severe impact on the seawater quality of Shanghai and Zhejiang at the middle stage of the seawater's EKC. Furthermore, this paper proposes an overall strategy and several "tailored" strategies to address coastal waters environment improvement for current poorly targeted policies at different stages of the seawater's EKC. [ABSTRACT FROM AUTHOR]

Abstract Both the direct and indirect need of rare earths (RE) are performing important functions in our daily life with their wide use in a range of products. However, previous studies have focused primarily on the direct use of RE and neglected the indirect effect, especially the indirect RE flow between economies. In this paper, we built an embodied rare earths flow network based on the global multi-regional input-output analysis framework and complex network theory, of which the community structure and small world nature are analyzed using complex network theory. We find that world embodied rare earths link network is clearly divided into 2 communities and the network can reveal the small world nature characteristics. Moreover, China, Germany and USA are the three most important economies based on the comprehensive analysis of the network's degree centrality, strength centrality, betweenness centrality and eigenvector centrality on the basis of network centrality theory. Furthermore, we analyze China's embodied RE outflow paths and the degree of dependence on embodied RE for each economy. Finally, some meaningful policy implications are provided. [ABSTRACT FROM AUTHOR]

Abstract The lack of knowledge about the interdependence between energy and metals hinders sustainable management of the two essential resources. In this study, a hybrid framework which combines the Environmentally Extended Input-Output Analysis (EEIOA) and Ecological Network Analysis (ENA) was constructed to evaluate energy-metals use and flows within China's economic system in 2012, from the perspective of nexus. Furthermore, the structural properties of nexus networks and mutual relationships between sectors were simultaneously explored. The results show that hybrid energy (direct energy + metals-related energy) and hybrid metals (direct metals + energy-related metals) used by all the sectors were 1.22 and 1.05 times their direct energy and direct metals use, respectively. In both hybrid energy and metal networks, mining industry and construction industry had a strong control and dependence relationship (over 50%) with other sectors, reflecting the tight inter-sectoral connection between energy use and metals use. Therefore, stabilizing these main control and dependence pathways is essential to the system's effective operation. In addition, alleviating excess industrial capacity and optimizing economic structure are two effective measures to improve the currently low energy-metals circulation efficiency within China's economy system. By revealing the nexus between energy and metals in China, this study provides important policy implications for trade-offs and synergies between energy and metals use. Graphical abstract Image 1 Highlights • The interdependence between energy and metals was quantified from a nexus perspective. • System stability and inter-sectoral energy and metals linkages in the nexus network were investigated. • The circulation of energy and metals within China's economic system were both in a state of low efficiency. • Feasible strategies were provided for sustainable energy and metals management. [ABSTRACT FROM AUTHOR]

By means of the three-scale input-output analysis, this study, taking Hebei Province in China as a case work, analyzes the water use in the provincial district and compares that between regional and urban economies. To the best of our knowledge, this paper pioneers providing a multi-scale perspective in a spectrum from global, national and regional scale, into regional water use allocation and water-saving policy making in Hebei province. The embodied water intensities for Hebei are revealed to be higher than that of the global average, but relatively approximate to that of the national average. The fact that water embodied in Hebei’s final demand is much lower than the direct water withdrawal is unveiled, with large amounts of foreign embodied water exports and domestic imports flowing through the primary and secondary industries. The network outlines detailed supply and demand chains of water resources in Hebei province from global, national, and regional scales, laying a solid foundation for reasonable allocation of water resources in regional economies in context of regional development and urban integration. [ABSTRACT FROM AUTHOR]

Rare earth elements (REEs) are irreplaceable in modern societies due to rising demands, especially amidst the urgent energy transition background. As the first ordered and the second most produced REE, lanthanum is widely used in conventional fields. This study investigates lanthanum flows and stocks in China by conducting a dynamic material flow analysis for the period of 2011–2020. The main results are that: 1) The registered quota production of La from 2011 to 2020 is 235,306 tons, and net La import accounts for 24.79% of the total input flows. 2) The accumulative surplus of La under the circumstance of quota production is 35,929 tons, with the in-use stock being 148,556 tons. 3) China is the net La importer of concentrates (133,769 tons) and net La exporter of primary, intermediate, and final products. The net La export is mainly in the form of primary products (76.27%). 4) The consumption of La increases steadily from 21,708 tons in 2011 to 31,580 tons in 2020. The top 5 applications are FCC (45.58%), rechargeable NiHM battery (16.97%), alloy (10.77%), optical glass (8.95%), and polishing powder (4.86%). Policy suggestions include expanding the demand market, adjusting the quota production system based on REEs, and improving investment in and guidance for R&D. • Lanthanum flows and stocks in China for the period of 2011–2020 are investigated. • The accumulative surplus of La under the quota system is 35,929 tons. • China is net importer of La concentrates and net exporter of La-containing products. • La consumption has kept growing, primarily applied in FCC and NiMH battery. [ABSTRACT FROM AUTHOR]

China's rapid urbanization has resulted in increasing household electricity consumption (HEC). However, significant urban-rural disparity exists due to different consumption behaviors and income levels. Thus, it is crucial to uncover the key drivers of HEC so that appropriate policies can be raised to facilitate the achievement of China's carbon neutrality targets. This study aims to uncover the heterogeneity of urban-rural HEC by accounting electricity consumption from six household services. Then, multiple regression models, containing both household internal and external factors, are established to investigate the drivers of urban-rural HEC based on the data from Chinese General Social Survey in 2015 and 2018. The results present that urban HEC is higher than rural HEC at both aggregate and single service levels. Household appliances are major positive drivers of urban-rural HEC. Household size and home life time also promote HEC, and their positive effects on urban households are higher. Non-electric energy has different substitution effects on urban-rural HEC. Pipeline gas and liquefied petroleum gas are major alternative energy sources for urban HEC. Coal and biomass usage can reduce rural HEC. Time-of-use electricity pricing restricts urban-rural HEC under different services. Publicity slightly facilitates urban household electricity conservation. Finally, policy recommendations, including electricity-saving appliances and technological promotion, economic instruments, and capacity building, are proposed to facilitate clean and efficient HEC. • The features and drivers of China's urban-rural household electricity consumption (HEC) are investigated. • Urban-rural disparity of China's HEC is uncovered by accounting service-based electricity consumption. • Urban HEC is higher than rural HEC at both aggregate and single service levels. • Household appliances are major positive drivers of urban-rural HEC. • Non-electrical energy has different substitution effects on urban-rural HEC. [ABSTRACT FROM AUTHOR]

Official promotion assessment standards are an important factor affecting the environmental governance of local governments. The study of the Chinese government adding the evaluation of ecological civilization to the official promotion assessment standards is of great significance to promote China's environmental pollution control and eco-environmental protection. Therefore, it is necessary to explore diversified ways of environmental governance from the perspective of improving the assessment standards for official promotion. Based on this background, this paper uses a variety of econometric models to compare the impact of traditional assessment standards and new assessment standards, including environmental factors on environmental quality. The results show that: (1) Different from the negative environmental impact brought by traditional assessment, when the official promotion assessment standards change, that is, when it is included in the environmental assessment, the official promotion incentive can actively promote the improvement of regional environmental quality, and this result has a more significant effect on the improvement of environmental quality in economically underdeveloped areas and vulnerable areas. (2) The mechanism test shows that the change of assessment standards will force officials to improve environmental quality by improving regional productivity. (3) the promotion of environmental supervision, represented by the development of information technology, helps strengthen the positive effect of the transformation of official assessment standards on the environment. However, it is unstable. This paper provides a useful reference for improving official promotion assessment standards, exploring diversified ways of environmental governance, and clarifying the effectiveness of the Chinese government's ecological environment reform. [ABSTRACT FROM AUTHOR]

The 2030 Agenda for Sustainable Development stipulates 17 Sustainable Development Goals (SDGs). The implementation of this agenda will mobilize countries worldwide to incorporate the SDGs into their national development strategies. The agenda does not specify how these goals are interconnected, thus limiting their implementation. In addition, air quality affects human life and plays a vital role in achieving these SDGs. Clarifying the interconnections between SDGs related to air pollution and other SDGs will accelerate the implementation of air protection and SDGs while simultaneously promoting policy coherence. In this paper, we use the latest calculation of the SDGs in China to construct national and provincial panel data to investigate the trade-offs and synergies among Chinese air pollution-related SDGs. The findings are as follows. First, most air pollution-related SDGs have synergetic relationships, except for SDG12, which has a trade-off relationship with other air pollution-related SDGs. Second, the synergies between air pollution-related SDGs and other SDGs far outweigh the trade-offs. Third, rapidly developing areas are more likely to experience a trade-off between economic development and air pollution problems. Fourth, geographic advantages in reducing air pollution, such as being adjacent to the sea, may weaken the synergies among air pollution-related SDGs and their synergies with other SDGs. These findings indicate that most air-pollution-related SDGs and interactions between air-pollution-related SDGs and other SDGs have substantial synergy; that is, measures aimed at one goal are conducive to the advancement of other goals. However, SDG12 reflects a trade-off relationship between economic development, environmental protection, and resource utilization. [ABSTRACT FROM AUTHOR]

• The PV potential of China's 239 civil airports was evaluated. • The airport PV in China is up to 2.5 GW with an annual output of 2.64 TWh. • The power generation potential highly matches the energy demand at airports. • Most airport PV systems can achieve a ROI of over 50% without any subsidy. • The meaning of airport PV is discussed in the context of transport electrification. The airport is one of the most fundamental infrastructures in our society, its terminal buildings and parking lots are ideal locations for photovoltaic (PV) installation. The future trend of the electrification of the aviation and automobile industries will increase the electricity demand at airports calls for the integration of PV systems with airport infrastructure. Understanding the benefits of airport PV systems is crucial for the stakeholders including investors, project developers and policymakers to promote PV sector development. Thus, evaluation of the PV potential and relevant economic performance of airports is essential. Combined with the geographic information system (GIS), the PV potential of the civil airports in China is investigated. The results show that potential PV capacity of China's 239 civil airports reaches up to 2.50 GW. The annual electricity demand of the aviation industry in 8 provinces can be self-satisfied via airport PV generation. Detailed economic analysis shows that all airport PV systems are profitable through appropriate investment and operation strategies. [ABSTRACT FROM AUTHOR]

To improve environmental quality, the Chinese government implemented a series of environmental policies, including the environmental information disclosure system, which is critical to promoting China's ecological development, and PM2.5 monitoring data, which constitute the most important and valued index. Using data from 120 cities in which the environmental information disclosure policy was implemented in China from 2008 to 2016, this research empirically tested the impact of air pollution on economic development and the transmission mechanism of this effect using a two-stage least squares regression model (2SLS). Additionally, this study innovatively tested the impact of environmental information disclosure on air pollution and economic development. Our results indicate that air pollution can hinder economic development and that spending on scientific research and financing polluters are two crucial transmission mechanisms. Disclosure of environmental information effectively reduces concealment of and failure to report pollution, enabling the environmental reports published by the government to more accurately reflect the air quality. By increasing the government's environmental protection expenditure, this disclosure system expands environmental protection employment and infrastructure construction. In this way, the negative externality of air pollution has been alleviated by the government's enhanced environmental governance. [ABSTRACT FROM AUTHOR]

Reasonable and effective use of renewable resources can reduce dependence on traditional fossil-based energy sources and reduce carbon emissions. This study mapped the spatial potentials of renewable resources (i.e., solar radiation, precipitation, wind, and geothermal resources) in China. The results showed that China's most abundant renewable resources are located in the southwestern regions, which are significantly different from the spatial distribution patterns of population and economic development. Four southwestern provinces (Tibet, Qinghai, Sichuan, and Yunnan) make up only 7% of the national gross domestic product (GDP) and 30% of the national land area but possess 58% of the renewable resources. We found a weak to moderate degree of negative correlation between the emergy density of renewable resources and GDP per capita on the administrative levels of the prefecture-level cities for the whole country and in its eastern, central, and western regions. This means that the socioeconomically underdeveloped Midwest has more abundant renewable resources. A distributed energy-economic system may help to bridge the regional gaps of renewable sources in China. These findings can support policy decisions for the better development and use of renewable resources in China. • The spatial distribution pattern of renewable resources was identified. • The national emergy line for renewable resources was depicted. • A correlation analysis of the GDP and renewable resources was conducted. • A distributed energy-economy system was proposed for China. [ABSTRACT FROM AUTHOR]

Improving energy efficiency and building a low-carbon economy are the important ways to resolve the current contradiction between economic growth and the environment in China. In this paper, we use the super-efficiency Slack-Based Measure model (super-efficiency SBM model) to measure the energy efficiency of 30 provinces in China, and then conduct Empirical Orthogonal Function (EOF) to analyze its spatial-temporal evolution. Moreover, we use the Geographically and Temporally Weighted Regression (GTWR) to analyze the spatial-temporal heterogeneity of its driving factors. The results show that: (i) during the sample period, China's energy efficiency shows a rapidly upward trend, accompanied by the gradually strengthening spatial pattern of the "eastern>central>western"; (ii) the spatial pattern of the "southern>northern" exhibited by the annual growth rate of energy efficiency experienced a process of weakening first and then gradually strengthening; (iii) the influencing effects of market openness, relative energy price and industry structure on energy efficiency have no significant heterogeneity as a whole; (iv) the effects of environmental regulation intensity, the marketization level, the technical level, energy consumption structure and economic development level have significant spatial heterogeneity, and the effects of energy conservation and emission reduction policies has significant temporal heterogeneity. Unlabelled Image • Spatial-temporal evolutions of energy efficiency and its growth are depicted using EOF. • The driving factors of energy efficiency are investigated using GTWR. • The spatial pattern of the "eastern > central > western" is dynamically strengthening. • The energy efficiency growth rate shows "southern > northern" dynamic evolution. • The same factors have different effects in the spatial and temporal dimensions. [ABSTRACT FROM AUTHOR]

• Beijing's multiperspective electricity-related carbon emissions are accounted for. • Beijing had a large amount of net inflow of electricity-related carbon emissions. • Hebei and Inner Mongolia contributed most of Beijing's emission net inflow. • The driving forces of Beijing's electricity-related carbon emissions are analyzed. Cities are the main consumers of electricity, and the environmental impact of electricity use in cities has received increasing attention; however, relevant studies focus mainly on carbon emissions from urban power generation and urban direct electricity consumption, and carbon emissions induced by urban indirect electricity consumption are largely ignored. Using the Intergovernmental Panel on Climate Change (IPCC) carbon inventory method, the network approach and the environmentally extended multiregional input–output model, our study quantifies Beijing's production-, supply- and consumption-based electricity-related carbon emissions in 2007–2015. Additionally, methods of decomposition analysis are used to assess the impacts of the driving factors. The results show the following: (1) In 2015, Beijing obtained 45.6 million tons and 38.9 million tons of net inflow of electricity-related carbon emissions through electricity trade and regional trade, respectively. (2) Beijing obtained a large amount of electricity-related carbon emissions by purchasing heavy industrial products from Hebei, while Beijing's electricity-related carbon emissions flowing to Tianjin and Hebei consisted mainly of service industry products. (3) The fuel structure and energy efficiency contributed to the decline in Beijing's production-based emissions. Interprovincial electricity transmission offset the growth of supply-based emissions in Beijing. Improved electricity efficiency and production technology helped reduce consumption-based emissions, and the consumption volume was the major driver of the growth in consumption-based emissions. This study not only enhances our understanding of the environmental impacts associated with urban electricity consumption but also provides a basis for cross-regional environmental responsibility allocation. [ABSTRACT FROM AUTHOR]

The power sector plays a significant role in China's energy transition and emission reduction strategy. Considering that the aggregation of the power sector from different sources in input-output (IO) tables will lead to the "aggregation bias problem", it is vital that we disaggregate the power sector using IO tables when analyzing and comparing the driving forces of embodied carbon emission changes in the power sector. This paper first disaggregates the power sector into seven subsectors; then, it uses structural decomposition analysis (SDA) to analyze the driving forces of embodied carbon emission changes in each subsector and allocates embodied emissions that occur from 2007 to 2015 according to the demand categories. The results show that the embodied carbon emissions from each clean energy sector were relatively lower than those from thermal power during the study period. Consumption volume was the main driving factor for the embodied carbon emission increments. From 2012 to 2015, the production structure was mainly responsible for the embodied emission increases in each clean energy sector, indicating that the embodied carbon emissions caused by power equipment updates or reconstruction processes should receive more attention. In addition, the embodied carbon emission changes induced by urban residential consumption on the thermal power showed a plateaued trend from 2007 to 2015. This paper provides support for the formulation of emission reduction measures and the low-carbon structural transformation of the power sector. [ABSTRACT FROM AUTHOR]

In armor protection fields, various ceramics/FRP laminated composite plates are increasingly applied because of superior comprehensive protection performances. A great deal of hole drilling operations are required for assembly and connection. However, only a few literatures are reported on the drilling technologies of ceramics/FRP laminated composites. In this study, the constant feed rate drilling of the Al 2 O 3 /GFRP laminated composite plate has been researched through the low-frequency vibration drilling along with a thin-wall diamond trepanning bit. A kinematic model for low-frequency axial vibration trepanning drilling has been established and used for analyzing the machining characteristics of the pulse cutting. To reveal the drilling effects of the Al 2 O 3 /GFRP laminated composites under the conventional drilling and low-frequency axial vibration drilling, the comparison experiments have been carried out, and then the axial force, hole wall roughness and hole exit defects under the above two drilling methods have been analyzed deeply. The results show that compared with the conventional drilling, the low-frequency axial vibration drilling can achieve the constant feed rate drilling of the Al 2 O 3 /GFRP laminated composites with better drilling quality. [ABSTRACT FROM AUTHOR]

The sea level rise caused by climate change has seriously threatened the sustainable development of island areas. As the third largest island in China, Chongming has constructed ecological islands for a long time and has paid special attention to local ecological issues and sustainable development issues. In the period of 2002–2012, the production-based CO 2 emissions of Chongming increased from 0.96 Mt tons to 2.05 Mt tons, with a lower growth rate than the national level. Due to the difficulties in obtaining research data, the existing research has not used the input-output method to evaluate the CO 2 emissions of Chongming. This paper calculates the consumption-based CO 2 emissions in Chongming between 2002 and 2012 based on an optimization method of matrix updating and an environmentally extended input-output model. Structural decomposition analysis (SDA) is also used to study the driving forces of consumption-based CO 2 emissions during this period. The results show that from 2002 to 2012, the average annual growth rate of Chongming's consumption-based CO 2 emissions was 12.74%. In 2002, consumption-based emissions were mainly caused by gross capital formation, and in 2007 and 2012, consumption-based emissions were mainly caused by domestic outflow. Additionally, changes in the final demand volume and final demand structure were the main drivers of the rapid growth in Chongming's consumption-based CO 2 emissions. Our study can help to strengthen the understanding of Chongming's CO 2 emission situation and provide some policy recommendations for building an ecological island. In addition, we have established the first input-output table of Chongming Island, which provides a data basis for future analyses of other environmental issues on Chongming Island. [ABSTRACT FROM AUTHOR]