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People in China have become concerned with the health threats associated with severe air pollution. As a result, behavioural adjustments and pollutant filtration product implementation have become common means for people to cope with pollution threats in their daily lives. However, a systematic awareness of the basic characteristics and mechanisms of such behaviours is lacking. This paper focuses on how residents engage in inverted quarantine in response to air pollution. We examine in detail their behavioural responses by conducting a questionnaire survey. Results show that individual avoidance behaviours are quite diverse and combined. Masks have been identified as the most widely adopted filtration product with the lowest input costs. High-income groups have a higher tendency to purchase expensive filtering devices compared with low-income groups and prefer to combine multiple protection strategies. In addition to the driving effect of income, individual psychological perception plays an important role in the decision making of households. A lower public confidence in the government further encourages individual self-protection. These findings urge the government to enhance their air pollution control efforts and their timeliness of disclosing pollution information. The significant driving effects of individual cognition factors also call for a proper guidance to achieve a rational public perception of air pollution. Although the health benefits of using pollutant filtering devices have been widely discussed and proven, the increased energy consumption and other environmental impacts resulting from the use of such products are easily neglected. It demands the implementation of stricter market entrance, improved energy efficiency standards and enhanced waste management.

Porous carbon materials are regarded as one of the most promising candidates for sodium-ion batteries (SIBs) due to their fast sodium storage performance. However, the inadequate initial coulombic efficiency (ICE) resulting from the large specific surface area still hinders the commercialization of porous carbon anodes. Thus, it is important to synthesize porous carbon anodes with high electrochemical performance and improved ICE. Here we prepare a nitrogen and oxygen rich porous carbon material (NOPC) and construct a uniform passivation layer using a sodium carboxymethyl cellulose (CMC) binder on the surface of the NOPC material. The uniform passivation layer effectively deactivates the functional groups and suppresses the decomposition of electrolytes, resulting in an excellent ICE of 90%, which is ultrahigh and competitive among the reported carbon-based anodes in SIBs. Specifically, the as-prepared porous carbon anode delivers a reversible capacity of 191.7 mA h g−1 after 1000 cycles at 10 A g−1 with a capacity retention of 90%. This work suggests a general method to improve the ICE of a carbon material and hopefully facilitates the commercialization process of SIBs.

Rechargeable aluminum ion battery (AIB) with high theoretical specific capacity, abundant elements and low cost engages considerable attention as a promising next generation energy storage and conversion system. Nevertheless, to date, one of the major barriers to pursuit better AIB is the limited applicable cathode materials with the ability to store aluminum highly reversibly. Herein, a highly reversible AIB is proposed using mesoporous TiO2 microparticles (M-TiO2) as the cathode material. The improved performance of TiO2/Al battery is ascribed to the high ionic conductivity and material stability, which is caused by the stable architecture with a mesoporous microstructure and no random aggregation of secondary particles. In addition, we conducted detailed characterization to gain deeper understanding of the Al3+ storage mechanism in anatase TiO2 for AIB. Our findings demonstrate clearly that Al3+ can be reversibly stored in anatase TiO2 by intercalation reactions based on ionic liquid electrolyte. Especially, DFT calculations were used to investigate the accurate insertion sites of aluminum ions in M-TiO2 and the volume changes of M-TiO2 cells during discharging. As for the controversial side reactions in AIBs, in this work, by normalized calculation, we confirm that M-TiO2 alone participate in the redox reaction. Moreover, cyclic voltammetry (CV) test was performed to investigate the pseudocapacitive behavior.

Conversion of CO2 into fuels via solar energy would be a promising strategy to reduce CO2 emissions and produce value-added carbon compounds. However, the development of efficient light-harvesting ...

Lithium metal batteries (LMBs) are among the most promising candidates for high energy-density batteries. However, dendrite growth constitutes the biggest stumbling block to its development. Herein...

Accurate accounting of greenhouse gas (GHG) emissions considering interregional trade are important for developing regional-specific strategies for climate mitigation in countries like China where vast heterogeneity exists among regions. Trade-related provincial CO2 emission accounts have been reported and analyzed for China using three independently developed multiregional input-output (MRIO) models which have been widely used. Here we show that significant divergence exists in both consumption-based and income-based CO2 emission accounts for Chinese provinces in 2012 using different MRIO models. For example, the difference of CO2 emissions for Shandong Province calculated from two MRIO models can reach 208Mt, more than the terrestrial emissions of Argentina, United Arab Emirates, or The Netherlands. Reducing such divergence, however, requires only the agreement among various MRIO models on a small number of critical data elements. Our results demonstrate the need of careful interpretation of previous studies on trade-related provincial GHG emission accounts in China, and prioritize future efforts to harmonize GHG emission accounting within China.

Exploring electrolytes of high safety is essential to pave the practical route for sodium-ion batteries (SIBs) toward their important applications in large-scale energy storage and power supplies. ...

The miniaturization and rapid development of portable and wearable electronics require significant advances in new energy storage devices with high capacities and excellent mechanical properties. Along with flexible Li-ion batteries (LIBs), flexible Na-ion batteries (SIBs) are among the most promising power devices for portable and wearable electronics. Unfortunately, advances in the field of flexible SIBs have been relatively stagnant. In this work, we created a flexible anode for SIBs by applying a simple ex situ electrospinning method to introduce oxygen vacancies (Vo) into a TiO2 structure (F–TiO2-x). Thanks to the oxygen vacancies and inclusion of N-doped carbon nanofibers (CNFs), the F–TiO2-x electrode can deliver an ultrahigh reversible capacity of 353 mAh g−1 at 0.1C. Even at a relatively high current rate of 1C, a charge capacity of 331 mAh g−1 can still be obtained after 1000 cycles. Furthermore, a sodium-ion full cell with F–TiO2-x—Na2/3Ni1/3Mn2/3O2 full cell was assembled, delivering a high average voltage of 2.6 V (after 200 cycles, a reversible capacity of 158 mAh g−1 can be retained). Combining both experimental and first-principles density functional theory (DFT) methods, we show that the introduction of oxygen vacancies can alter the electronic structure and enhance the electronic conductivity of the electrode. Additionally, the wrapped N-doped CNFs can further enhance the sodium diffusion kinetics of sodium storage. Overall, the study of preparing an oxygen vacancy-containing flexible electrode is expected to offer new insights into fabricating high capacity flexible electrodes for advanced secondary batteries including SIBs.

With the maturity of big data technology, analyzing residents’ travel habits and tracks has become an important research direction in the field of intelligent transportation study. In this paper, based on the subway and bus ride data, a subway-bus double-layer network model was established using complex network theory, taking the optimal traffic efficiency as the goal, the structure of intelligent bus network optimization method is proposed, and an empirical study is conducted on the Beijing bus network. In the empirical study, by adding or deleting bus station in the network, obtain an efficient network structure, the goal of optimal operation efficiency of the bus network was realized, and the theoretical and practical research on solving the problem of transportation line network planning with big data of traffic travel was enriched.

This study investigates the impact of the human capital index, globalization, and financial development on carbon dioxide of grouping OECD countries using pool mean group estimation technique from 1990 to 2015. This study also applies the second-generation cross-sectional augmented Dickey-Fuller and cross-sectional Im, Pesaran, Shin panel (CIPS) unit root, and the latest (Westerlund 2008) cointegration tests for further investigations. The result shows that both the human development index and financial development stimulate environmental improvement by using PMG long-run panel estimation approach. Furthermore, the pairwise Dumitrescu-Hurlin panel causality results prove the two-way causal association between financial development and carbon emissions. The unidirectional causality running from globalization and human development index towards carbon emission is also supported. Based on the aforementioned results, we provide a set of recommendations for policy implication.

Transport sector of Pakistan contributes more than one half to the national energy consumption. This sector is dominated by road transportation and mainly relies on fossil fuels. The country is going through rapid unplanned urbanization, which can lead to detrimental health and ecological consequences by intensifying road transport energy consumption. Therefore, the current study investigates the effect of urbanization on road sector energy consumption controlling for economic growth, road infrastructure, and industrialization. The autoregressive distributed lag (ARDL) approach is used to examine the long-run and short-run relationship between variables over the period 1971 to 2018. The vector error correction model (VECM) is employed to analyze the causality between variables. The results disclose a significant positive contribution of urbanization to road sector energy consumption. Further, road infrastructure, economic growth, and industrialization stimulate road transport energy consumption. Feedback effect exists between urbanization and road transport energy consumption, while economic growth Granger causes road sector energy consumption, urbanization, and road infrastructure. The findings imply that energy conservation and sustainable urbanization policies are a better choice under the current economic situation. Also, road infrastructure development in rural areas may reduce rural to urban migration.

Enhanced terahertz wave generation via Stokes wave recycling in a non-synchronously picosecond pulse pump configuration has been demonstrated. It is theoretically analyzed that under the condition of high pump peak power density, the oscillation of the strong 1st order Stokes wave could benefit the higher order Stokes wave emission and terahertz wave generation. In the experiment, 5.71 times enhancement of terahertz wave generation was obtained via Stokes wave recycling in the non-synchronously picosecond pulse pumped terahertz parametric generator compared with the conventional single-pass terahertz parametric generation. The maximum terahertz wave average power was 61.7 μW under the pump power of 20 W and the cavity length of 170 mm, while the maximum power conversion efficiency was 3.085 × 10-6.

Sodium-ion batteries (SIBs) have attracted wide attention because of their prospects for grid-scale electrical regulation and cost effectiveness of sodium. In this regard, iron oxides (FeOx) are co...

To realize the emission reduction targets, it is essential to understand how technical and structural variations of an economy can lead to emission changes. This paper establishes the carbon dioxide (CO2) emissions elasticity indicators of technical and final demand coefficients from the demand perspective as well as allocation and primary input coefficients from the supply perspective, based on the input-output technique combined with sensitivity analysis. We apply these indicators to the Chinese economy for the year 2012. The results show that with every 1% decrease of self-supplied intermediate products in the Production and supply of electricity and heat and Smelting and pressing of ferrous metals (the two largest CO2 emitting sectors) could reduce CO2 emissions from the whole economy by 20.6 Mt and 11.3 Mt from the demand perspective, accounting for 0.22% and 0.12% of the national total CO2 emissions, respectively. It could also mitigate 22.2 Mt and 8.7 Mt from the supply perspective, accounting for 0.24% and 0.09% of the national total, respectively. In addition, 1% decrease of final demand coefficient of the Construction in Capital Formation could exert great indirect effects on many sectors, and lead to 37.4 Mt (0.40%) emission reduction from the whole economy. The absolute reduction due to the variation of primary input coefficients is relatively small. By analyzing these important intersectoral linkages of CO2 emissions within the economy from both demand and supply perspectives, the most important economic transactions between sectors as well as supply and demand patterns to reduce emissions are identified. These results can help guide the development of potential effective emission mitigation policies and the methods can also be applied to other countries and regions.

Two exchangeable LSPR modes with different coupling field are observed in calculating magnetic field intensity in accordance with adjusting geometrical parameters. Compared with planar nanostructures, three-dimensional windmills show stronger optical activity, and the maximum value of the asymmetry g-factor was 0.6. The numerical simulation results in this paper also contain the optimal geometrical parameters to achieve the best circular dichroism effect at different resonance modes. The results give a contribution to the design of novel chiral optical nanostructures.

China is vigorously developing a circular economy to alleviate environmental degradation and resource shortages. In a circular economic system, resource recovery and pollutant treatment are core subsystems. To improve resource utilization efficiencies and reduce pollutant emissions in the circular economic system, this study first proposes a comprehensive model using game theory and a data envelopment analysis (DEA) method. Then, to identify the technology gaps between circular economic systems, the study proposes a game meta-frontier DEA model. The proposed models are then applied to evaluate the circular economic systems in China’s different provinces from 2007 to 2016. The results show a continuing conflict between economic growth, environmental protection, and resource recycling in China. In addition, the efficiency of pollution treatment and waste disposal (PTWD) and the production efficiency of the circular economic systems differ when different frontiers are applied. The improvement direction and potential efficiencies also differ. The production technology and PTWD technology in Eastern China are the highest, while the technology levels in Western China are the lowest. Based on management potential and technological potential, the circular economic systems in China are divided into four categories. For each category, this study provides the specific recommendations for improving production/PTWD efficiency.

The coal industry is an important part of the national economy in China which provides the necessary energy and other resources to support economic development. To alleviate environmental pressures in China, there is an urgent need to change the national structure of the coal industry and to rationally analyze the coal industry chain (CIC). To achieve this purpose, a combined methodology of input-output analysis and an APL model, was used. Input-output tables from 2002 to 2015 were adopted, and the evolution of China's industrial chain was empirically analyzed at the macroscopic level. The results of the research show that coal production and the supply of electric power, steam and hot water constitute one of the four most important industrial chains in China. Industries that are firmly related to the coal industry are the chemical industry, smelting and pressing metals, general purpose electrical equipment manufacturing, power supply, and the construction industries. The number of intermediate links between the coal industry and various industries are increasing, and the economic distance has been extended. 2005 and 2007 were the most complex years for the CIC network, as these are most closely related to each other. Since 2010, the complexity of the CIC network has decreased, and the relationship between industries has begun to decline. It is of great importance for the government of China to determine the national economic strategy and formulate relevant policies by analyzing the industrial chain relationships and its trends of evolution.

The dilemma of rising environmental pollution in recent decades has raised the demand for clean energy sources. However, some newly developed energy sources, such as biomass energy, may or may not contribute to reducing environmental stress. This study investigates biomass energy consumption and environmental pollution in BRICS countries by applying the generalized system method of moment (GMM) model for empirical estimation from 1992 to 2013. The results show that biomass energy consumption behaves as a clean energy source in reducing environmental pollution. The study also found support for the presence of an N-shaped relationship between income and pollution and found that trade openness is the only factor that contributes to pollution in BRICS countries. These results can assist policymakers in considering biomass energy as a clean source of energy in the effort to achieve both energy security and environmental sustainability.

This study analyzes the non-linear relationship between urbanization and CO2 emissions over the period 1971 to 2014 in Indonesia. The findings unveil an inverted U-shaped relationship between urbanization and CO2 emissions. Urbanization increases CO2 emissions, but after achieving a certain level, it negatively impacts emissions. Economic growth and energy intensity increase CO2 emissions, while trade openness has no significant effect on CO2 emissions. Further, we have validated the robustness of results by using the ecological carbon footprint as a proxy of environmental degradation. The results of the causality test show unidirectional causality running from economic growth to emissions and energy intensity, and feedback effect between urbanization and emissions. Finally, several policy measures are proposed to improve the environment without reducing the urbanization level.

Sources of renewable energy have received wide attention in the literature because of serious threats to the environment. However, some renewable resources, including biomass energy role is debatable in the energy economics literature. This empirical work focuses to analyze the role of biomass energy in carbon dioxide (CO2) emissions using the framework of the environmental Kuznets curve (EKC) in Pakistan over the period from 1980 to 2015. The bound testing approach suggests there is cointegration among study variables. The study uses an auto-regressive distributed lag model (ARDL) with a structural break in the series. To summarize the findings of the study, it can be inferred that biomass energy increase CO2 emissions. In addition, biomass energy helps to form a U-shaped relationship between income and CO2 emissions that support the EKC hypothesis. Also, the feedback hypothesis is found between biomass energy and CO2 emissions. The findings would guide policymaker with practical guidelines to formulate policies to utilize a high amount of biomass energy in a sustainable manner.

This study contributes to the literature by estimating the interaction effects of economic growth and renewable energy consumption on carbon dioxide (CO2) emissions with the inclusion of human capital. The interaction between economic growth and renewable energy consumption suggests how income level affects energy consumption and CO2 emissions. The study applies three-stage least square and ridge regression methods with Pakistani data from 1980 to 2014. The empirical findings show that the interaction effect of income and renewable energy contributes to CO2 emissions. Besides, trade openness also increases CO2 emissions, while the human capital mitigates CO2 emissions. Furthermore, the moderating effect of economic growth helps to form the environmental Kuznets curve (EKC) hypothesis in Pakistan.

This study focuses to investigate the relationship between globalization and the ecological footprint for Malaysia from 1971 to 2014. The results of the Bayer and Hanck cointegration test and the ARDL bound test show the existence of cointegration among variables. The findings disclose that globalization is not a significant determinant of the ecological footprint; however, it significantly increases the ecological carbon footprint. Energy consumption and economic growth stimulate the ecological footprint and carbon footprint in Malaysia. Population density reduces the ecological footprint and carbon footprint. Further, financial development mitigates the ecological footprint. The causality results disclose the feedback hypothesis between energy consumption and economic growth in the long run and short run.

On-line recycling, as an emerging recycling method, can effectively tackle the problem of difficult recycling of electronic waste and irregular recycling channels. Based on the characteristics of on-line recycling and previous studies, an extended Theory of Planned Behaviour (TPB) theoretical framework has been built to explore residents’ willingness to participate in e-waste on-line recycling and its influencing factors through a nationwide questionnaire survey. According to an empirical analysis of 1225 valid questionnaires collected from seven regions in China, the results show that perceived behavioural control, subjective norms, attitudes, and economic motivation have significantly positive impact on the willingness to on-line recycling behaviour. This indicates that the convenience of on-line recycling, compared with traditional recycling, is the most attractive factor for residents to participate in on-line recycling. We further examined the moderating effect of income level on economic motivation. Although the economic benefits of on-line recycling, which are much higher than those of traditional recycling, will increase the willingness of residents to participate in on-line recycling, residents with lower incomes are more likely to demand higher returns through on-line recycling. Finally, relevant policy recommendations for promoting on-line recycling behaviour are proposed.

The linkage between high concentration of greenhouse gases (GHGs) and climate change is well recognized as there is severe influence of climate change on public health. Carbon dioxide is most prominent GHG which deteriorates the environment and impacts human health. On the parallel, economic growth also affects health conditions sometimes positively or vice versa. The objective of this research work is to examine the dynamic linkages among CO2 emissions, health expenditures, and economic growth in the presence of gross fixed capital formation and per capita trade by using auto regressive distributive lag (ARDL) model for Pakistan covering annual data from the year 1995-2017. Our empirical results show that there is significant long run as well as short-term causal relationship between health expenditure, CO2 emissions, and economic growth in Pakistan. Bidirectional relationship of Granger causality is found between health expenditures and CO2 emissions, and further between health expenditures and economic growth. Short-run unidirectional causality is running from carbon emissions to health-related expenditures. The bidirectional causal relationship is also investigated between carbon emissions and growth as well as gross fixed capital formation and growth. Then, policy recommendations towards controlling pollution, particularly CO2 emissions and health expenditures without compromising economic growth are suggested. Graphical abstract .

There is a notable discrepancy between intention on household waste sorting and the actions taken to support this environmental initiative among residents in China. This study aims to explore the influences of personal attitudes, facilities accessibility, and government stimulus on this discrepancy. Built on an integrated framework of Theory of Planned Behaviour (TPB) and Norm Activation Model (NAM), this study examines the relationship between intention and household waste sorting behaviour considering the psychological behavioural antecedents and circumstantial constraints among Chinese residents. Results from a questionnaire survey administered in China confirm the discrepancy, and show that the link between intention and behaviour on waste sorting is weakened after adding the influencing paths from the factors of facilities accessibility and government stimulus to waste sorting behaviour: however, the presence of these two factors directly promote waste sorting behaviour, but do not moderate the intention-behaviour relationship as their interaction items with behavioural intention are not significantly related to waste sorting behaviour. Furthermore, the personal norm is found to be the major factor influencing intentions of Chinese residents towards waste sorting while both subjective norms and perceived behavioural control were unexpectedly found to have no significant influence thereon. These findings are useful for promotion and planning of waste sorting by policy-makers to ease the waste disposal problem.

Iron fluoride cathode for lithium batteries intrigues researchers for decades due to high capacity and low cost, but suffers from poor electronic and ionic conductivity. Hierarchical micro/nano construction with preferred orientation growth can shorten ion diffusion pathway and facilitate electron transportation without inducing side reactions. Here, FeF3·0.33H2O hierarchical microspheres self-assembled by octagonal single crystal slices are prepared. Benefiting from the artful structure, SAED and XRD characterizations confirm that the octagonal single crystal slices provides more lithium ions intercalation positions (4c sites). Electrochemical tests demonstrate that the well designed FeF3·0.33H2O single crystal (FFH-S) delivers 30 mAh g−1 higher capacity (172 mAh g−1 at 0.1C) than the common FeF3·0.33H2O polycrystal (FFH-P). In-situ XRD combined with theoretic calculation elucidate the difference in lithium storage capacity. Instructive argument that single crystal octagon slices with [110] oriented growth provide more active sites for lithium ions intercalation contributes to the preparation of high performance iron fluoride cathode materials for rechargeable battery.

Lithium (Li) metal anode is among the most promising anodes due to its high energy density. However, the long-standing issue of Li dendrites growth hinders the practical application of lithium metal batteries (LMBs) in portable electronics and electric vehicles. Engineering a dendrite-free Li metal anode is therefore critical for the development of long-life batteries. Here, an artificial LiF host with cuboid feature is constructed on Li metal surface by a facial one-step reaction of ammonium hydrogen difluoride (NH4HF2) with bare Li metal. During cycling, Li grows continuously from the bottom gaps to the top of the LiF host and finally cover the surface of the modified anode. Particularly, with the increasing of cycling capacity, the Li metal tend to deposit into scaly morphology which contributes to a dendrite-free anode. The as-obtained smooth Li anodes enabled stable cycling in working batteries with a low overpotential and a high Coulombic efficiency (CE) of 98.5% at the current density of 1 mA cm−2. This work provides a facile approach to prepare LiF-rich Li anode which paves the way to construct high-energy and safe LMBs.

This paper empirically examines the relationship between corporate financial performance and adoption of industrial waste recycling in Chinese chemical industry. We employ an event study methodology with the application of propensity score matching to establish the comparison group for our analyses. The result shows that corporate internal operating characteristics such as cost intensity and asset turnover, rather than environmental management experience, are key determinants of industrial waste recycling adoption. Reputation effect from industrial waste recycling adoption is significant as evidenced with an increase of sales growth at the adoption year from our data analyses. However, the reputation effect lapses without significant change after the adoption year. There is a lack of performance effect of industrial waste recycling adoption with corporate cost saving and profitability for Chinese chemical industries to enhance their competency in these performance parameters.

To identify the similarities and differences of the role that driving factors playing in carbon dioxide emissions between passenger and freight transportation sectors, this work uses an LMDI (Log-Mean Divisia Index) method to decompose factors that influence carbon dioxide emissions in China’s passenger and freight transportation sectors between 1990 and 2015. The results indicate that: (1) Carbon dioxide emissions of passenger and freight transportation underwent growth from 1990 to 2015; (2) Per capita GDP, and population promoted the increase of carbon dioxide emissions for both passenger and freight transportation, and transportation structure promoted the increase of carbon dioxide emissions for freight. Among them the economic factor made the biggest contribution; (3) Activity intensity restrained the increase of carbon dioxide emissions and transportation structure restrained the increase of carbon dioxide emissions for passenger.

As the world’s main energy consumer, China faces an increasingly prominent conflict between its growing energy consumption and its unreasonable energy consumption structure. To optimize China's energy consumption structure, while simultaneously controlling its carbon emissions, this study proposes two models for the analysis of China’s energy configuration and energy consumption structure based on the data envelopment analysis (DEA) method. A fixed-sum input DEA model is proposed with which the energy input frontier is determined under consideration of China's energy shortage constraint. Furthermore, an energy consumption structure measurement model is developed to determine the adjustment direction and potential of the current energy consumption structure. The proposed models are further applied for the practical energy consumption structure evaluation in Chinese provinces. The obtained results show that almost all provinces suffer from an inefficient energy configuration and Eastern China experiences severe energy shortage. In addition, all provinces currently have unreasonable energy consumption structures. In particular, the proportion of gas consumption to total energy usage should be increased in all provinces. Furthermore, Chinese provinces with inefficient energy structures exhibit the geographical feature. The coal adjustment ratios in the central and western regions account for 70% of the total, which is much higher than the coal adjustment rate of the eastern region (50%). Based on these results, policies are also suggested to adjust China's energy consumption structure, such as reducing high carbon energy, implementing energy price reform, carbon tax, and clean energy subsidy.

To clarify the spatial characteristics of CO2 emissions, economic externalities of spatial units are transplanted into CO2 emissions research. Furthermore, to identify emissions reduction pathways, spatial econometric models are constructed based on the patent data about energy conservation and emissions reduction. The key results are: (1) The kernel density plot of China's CO2 emissions shows an obvious right-averse state, and the peak is getting lower. Therefore, we can conclude that CO2 emissions in China are increasing, and polarisation of CO2 emissions is serious; (2) Due to the similarity and connectivity exist in spatial units, China's CO2 emissions have shown a stable spatial agglomeration effect from global and local perspectives; (3) Based on adjacent, geographic, and economic distance matrices, energy technological progress has played a positive emissions reduction role on China's CO2 emissions from the perspective patent data about energy saving and emissions reduction. Finally, on the basis of the above conclusions, some policy implications have been proposed accordingly.

The device of multi-pass-cell (MPC) could broaden the spectra of ultrafast laser pulses based on the self-phase-modulation (SPM) effect, which is composed of two concave mirrors and nonlinear mediums. In this paper, the pulse duration of 172 fs is compressed from a 11.3 ps Nd: YVO4 regenerative amplifier at the repetition rate of 1 kHz by using two stages of MPC systems. The pulse duration is shortened by a factor of 66, and the pulse energy of 117 μJ is obtained with a total efficiency of 51%. With high average power Nd-doped laser systems at 10 ps level, this method has the potential to generate high power femtosecond lasers with high efficiency, compact configuration, and low cost.

We demonstrate a diode-pumped femtosecond Yb:CaGdAlO4 (Yb:CALGO) laser with a semiconductor saturable absorber mirror (SESAM) for stable mode-locking operation. A perfect beam profile is measured under 10 W output power with $M_{x}^{2}$ = 1.017 and $M_{y}^{2}$ = 1.016 in the horizontal and vertical directions, respectively. At the repetition rate of 71.66 MHz, the optical pulse duration is 247 fs and the pulse energy is 140 nJ at the central wavelength of 1041 nm, corresponding to a peak power of 0.56 MW. In addition, we also generate continuous wave (CW) power of more than 15 W with TEM00 mode, corresponding to an optical-to-optical efficiency of 44.1%.

Developing localized climate mitigation strategies needs an understanding of how global consumption drives local carbon dioxide (CO2) emissions with a fine spatial resolution. There is no study that provides a spatially explicit mapping of global carbon footprint in China―the world’s largest CO2 emitter―simultaneously considering both international and interprovincial trade. Here we map CO2 emissions in China driven by global consumption in 2012 at a high spatial resolution (10 km × 10 km) using a detailed, firm-level emission inventory. Our results show that the carbon footprints of foreign regions in China are concentrated in key manufacturing hubs, including the Yangtze River Delta, Pearl River Delta, and North China Plain. Approximately 1% of the land area holds 75% of the global carbon footprint in China. The carbon footprint hotspots in China identified are the key places in which collaborative mitigation efforts between China and downstream parties that drive those emissions., There lacks a spatially explicit mapping of global carbon footprint in China that considers both international and interprovincial trade. Here the authors map the carbon footprints of global regions in China and show the hotspots concentrated in key manufacturing hubs, including the Yangtze River Delta, Pearl River Delta, and North China Plain.

The rapid growth of the Chinese economy has resulted in great pressure on the environment: technological innovation is the fundamental pathway for improvement the efficiency in the process of energy saving and emission reduction. Based on large-scale technical text data in 31 Chinese provinces from 1985 to 2017, the Latent Dirichlet Allocation (LDA) topic model is introduced to technology content analysis. Then the LDA provincial-topic model is constructed, the subject and object of energy technology are jointly modelled, and the relationship between technology subject and technology have been region studied. The energy saving and emission reduction technology research direction in 31 provinces of China in the past 30 years has been examined: the status and level of technical reserves in each province have been evaluated, and the heterogeneity of provincial patent subject content has been compared. The research found that, despite the cumulative patent record (No. 1 world ranking), similarities in research directions in different provinces of China caused by poor regional technology mobility are a growing problem for Chinese energy technology, indicating much repeated research and development in different regions of China. Targeted suggestions on inter-provincial technology transfer and cooperation on energy technology development have been put forward.

High energy conservation and emission reduction (ECER) requirements across industries in the Beijing–Tianjin–Hebei (BTH) region have been proposed along with the transformation of China’s economic development mode. However, the energy consumption rebound effect, as an important proxy for achieving sustainable low-carbon development, has not been adequately investigated across industrial enterprises in this area. This study adopts an alternative estimation model based on neoclassical economic theory to measure the energy rebound effect of industrial enterprises in the BTH region from 1996 to 2015. Four main results are obtained. First, the energy rebound effects in Beijing, Tianjin, and Hebei are significantly different in the temporal and spatial dimensions. Second, technological progress does not reduce energy consumption, and the local government must simultaneously consider technological progress, industrial structure, and policy formulation to achieve the ECER goals. Third, ECER policies combined with government administrative measures do not have an impact on reducing energy consumption. Fourth, in the process of implementing the integration development of the BTH region, Hebei faces greater pressure to attain ECER goals in the future than the other regions. This study provides suggestions based on these derived results from the perspectives of market-oriented measures, management factors, development mode, and regional cooperation to achieve the sustainable development of the BTH region.

Reducing CO 2 emissions is a hot topic, and an important policy to achieve this target is carbon tax. When an enterprise is subject to a carbon tax, it has to pay this extra fee for the long-term if it does not upgrade its production technology. It needs to pay a certain upgrade fee in the short-term if it chooses to upgrade its plant. Thus, it has been an important problem for enterprises seeking to balance the trade-off between the ‘long-term tax fee’ and the ‘short-term upgrade fee’. This paper explores how to optimise an enterprise’s production technology upgrade strategy based on existing low-carbon technologies, to minimise the total upgrade cost subject to an expected total cost per product. An integer programming model is proposed to formulate the problem, and a ‘multi-agent system – genetic algorithm’ method is presented for its solution. The model is applied to a numerical example and the results indicate that the proposed method is feasible. The impacts of carbon tax and enterprise’s expected cost on its technology upgrade strategy are further discussed.

To clarify the current situation, hotspots, and development trends, in the field of climate change adaptation, we analysed a massive literature dataset from the Web of Science database by bibliometric method. By characterising the data about each publication, the result indicate that the field of climate change adaptation has entered a stage of rapid development. The USA occupies a leading position in terms of comprehensive strength with the largest publications output as well as a greater influence therewith. The most productive journal, author, and institution are Climatic Change, Ford JD from Canada, and The Chinese Academy of Science, respectively. Collaboration in this field continues to strengthen, but the growth rates at national levels are relatively low. In addition, the frequency and co-occurrence analysis of keywords reveals ten important research topics: climate change, adaptation, vulnerability, ecosystem, socio-economic system, agriculture, region, extreme event, mitigation, and sustainability, as the foci of climate change adaptation. “Vulnerability” is in a core position in all keywords with the strongest betweenness therein. The results of this work will help researchers clarify the current situation in climate change adaptation science but also provide guidance for future research.

Among all transportation modes, how do people choose their strategy when commuting? To better understand travel behaviour in new era, we introduce the perspective of “Multi-Choice” to complement that of existing “Single-Choice” based on the random utility maximisation theory and focus on actual travel data from the Pronto! system in Seattle in 2015, to test such a theory as well as other geographical and demographical data. By using mixed multiple regression, we find that at the peak of weekday use, the accessibility of other transportation modes (quantified by their density of infrastructure) could affect the departure flow of the Pronto! stations around them (within a 0.5 km buffer), but in a different trend in terms of multi-choice process. Besides those, we also find that the density of the points of interest around the station could positively affect departure flows on weekends, while the traffic-related factors did not. The current study broadens the traditional perspective of travel demand models by introducing a multi-choice option, and testing it against actual mode choices in people's daily behaviour using shared-bicycle data from Pronto!, Seattle.

Inter-firm collaboration is an effective way to achieve carbon emission reduction by sustainable consumption of waste resources. To find out how to bring collaborative effects to bear upon emission reduction for multiple-firm networks, industrial symbiosis is taken as a tool for inter-firm cooperation on carbon emission reduction (CER). The input-output matrix is built to identify the carbon footprint within the flows among the industrial firms in a symbiotic network. Fuzzy goals programming is employed to convert the parameter of amount of carbon emissions to the degree of satisfaction, which avoids the problem whereby the carbon emissions of different industrial firms are not comparable across different demographics. An optimisation model is then constructed with the constraint of both product demand and CER cost. Finally, there is a scenario simulation of CER cooperation from perspective of industrial symbiosis for the iron and steel industry. It provides empirical experience from which industrial firms can implement CER cooperation through industrial symbiosis.

The analysis of the characteristics of carbon flows between regions is critical for China to deploy effective regional mitigation strategies. Different accounting principles exert a significant influence on China’s regional carbon emissions, especially the fairness of carbon emission reduction targets, and the responsibility for reducing emissions. An input-output model was established, based on the input-output data of 2007 and 2012, to evaluate the characteristics of regional carbon flow and the change in carbon emission from different industries, and to analyse the changes in carbon emissions under production-based, and consumption-based, principles in 30 provinces. The results show that the carbon emissions in each region and sector are different: from the eastern region to the western region they show a downward trend, and the embodied carbon flow accounts for a large proportion of the total. Secondary industries are a major contributor to carbon emissions and there is a signifiant influence exerted on the results of carbon emission accounting in various provinces of China under different accounting principles. Therefore, to meet national emission reduction targets, the provinces need to pay considerable attention to the choice of accounting principles and achieve the principle of fairness and impartiality. It will provide a reference for the future division of responsibility for carbon emissions in provinces of China.

Hard carbon (HC) has become one of the prospective anode materials for sodium-ion batteries (SIBs), but its application suffers from the low electron conductivity and poor ion-diffusion kinetics. In this study, the melting and evaporation process of neutral salt was first introduced to produce nitrogen-rich interpenetrated porous HC (NIP-HC) as the anode for SIBs. Such a protocol allows for the first-demonstrated porous structure for HC materials with desired electronic conductivity and much improved rate performance than the conventional porous structure. As a result, high reversible capacity (358 mA h g-1) and enhanced rate property (239.8 mA h g-1 at 2 A g-1) are achieved with improved electrode kinetics and electron conductivity because of the accelerated charge transfer derived from the unique porosity and nitrogen heteroatom-doping. More interestingly, the increase of the surface area of NIP-HC does not lead to a decrease of the initial efficiency. At the same time, a high plateau capacity (172.8 mA h g-1) can be obtained below 0.1 V, which shows great potential for practical application in the full cells. As suggested by IG/ID from Raman tests, the degree of graphitization increases accompanied by the melting and evaporation process, which improves the electrical conductivity of the HC material as well. Furthermore, according to first-principle calculations, it is found that the nitrogen is conducive to increasing the electron density around the Fermi level, which intrinsically enhances the electrical conductivity and enriches active sites for sodium-ion storage. The result from this study has provided insights into producing interpenetrated porous HC by a simple and novel salt melting and evaporation process and enriched the methods of pore structure preparation.

Optical properties of the asymmetric nanoring/ellipsoid dimers with breaking of geometric symmetry are investigated theoretically. A tunable high-order surface plasmonic resonance is achieved. It is demonstrated that such high-order resonances result from the plasmonic coupling between the modes of a nanoellipsoid and of an asymmetric nanoring. Interestingly, a current loop is observed on the nanoellipsoid under coupling of the two nanostructures. The surface plasmonic resonance of this nanostructure can also produce enhanced local fields that can be applied in surface-enhanced spectroscopy and biosensing.

This research analyses how information publicity influences residents’ behaviour intentions in regard to e-waste recycling. We combine Theory of Planned Behaviour and Norm-activation Theory to build a research model, through scale development and questionnaire design, we carry out field research in Shandong Province, China. We collect 462 valid questionnaires as basic data for the research. We utilise exploratory factor analysis and structural equation model for data analysis and hypothesis test, and the results show that information publicity cannot directly influence residents’ behaviour intentions, but indirectly affect their intentions through two mediating variables – Personal norm and Recycling attitude. We think current information publicity about e-waste recycling is insufficient, or the publicity content thereof does not actually promote the willingness to recycle. So, we should improve the frequency of publicity events and focus on their publicity content.

The major consumption of energy around the globe is related to human activities. However, it may be essential to quantify how renewable energy consumption influence process of human development. This particular area of research still needs to be explored. Thus, this paper explores the relationship between renewable energy consumption, economic growth and human development index for 1990–2014 in Pakistan by using Two-Stage Least Square (2SLS) method. Empirical results reveal that renewable energy consumption does not improve the situation of the human development process in Pakistan. More, interestingly higher the income of the country the lower is level of human development. In addition, the CO2 emission is helpful to improve human development index. Furthermore, trade openness discourages human development process in Pakistan. Furthermore, causality analysis confirms feedback hypothesis between environmental factor and human development process in the long run path. These novel findings would help policymaker and government officials to better understand the role of renewable energy and economic growth in the human development process in Pakistan.

As an increasingly accepted way of relieving global warming, collaborative carbon dioxide (CO2) abatement could improve not only emission performance, but also cost-effectiveness of abatement. In this study, we analyze the cost savings and benefits of collaborative abatement in the context of China by using data envelopment analysis (DEA) approach. Specifically, we establish 63 collaborative abatement scenarios by dividing the Mainland China into six main regions, and then estimate the costs savings in each collaboration abatement scenario. Through investigating the gains for each region in various scenarios, the best collaborative partners for each region are suggested from perspectives of benefit maximization. Furthermore, the contribution of each region to collaborative abatement cost saving is also differentiated with the Shapley value approach.

The policy debate on economic growth and CO2 emissions is topical: corruption may affect this relationship by raising pollution at given income levels and by reducing per capita income. This research proposed a newly formulated conceptual framework to explore the moderating role of corruption on the relationship between growth and CO2 emissions by applying a partial least square regression model for a panel of BRICS countries from 1996 to 2015. Overall, from our empirical findings, we infer that the moderating role of corruption is crucial in the relationship between economic growth and carbon dioxide emissions and control of corruption reduce CO2 emissions. Furthermore, a significant moderating effect of corruption is observed on the relationship between urbanisation and carbon dioxide emissions in the case of BRICS countries, which signifies poor environmental performance therein. Also, control of corruption has a moderating effect on the relationship between trade and CO2 emissions. The variance importance analysis confirms the reliability of our results. The novel finding of the study not only advances the prior literature also provides a more clearer picture of the growth-emission nexus. The new findings can be of special interest to policymakers as they seek to control pollution at national level.

Rapid mass migration into cities and economic growth have created various problems of sustainability. The increasing household solid waste, bringing about environmental pollution and land occupation, is among the concerns and separate collection is recognised as a sound way to dispose it. However, separate collection behaviours are not common in China, and the research into the dynamics of urban residents' separate collection intentions for household solid waste is scarce. For filling this gap, we extend the theory of planned behaviour to explore the antecedents of separate collection intentions for household solid waste and identify their effects on residents' willingness to pay for separate collection by other organisations. The results show that separate collection intentions towards household solid waste are significantly influenced by the behaviours of others, facility conditions, and moral obligations, while their willingness to pay for separate collection is also affected by age, perceptions of results and government policies. In conclusion, urban residents’ willingness to pay is more sensitive to perceptions of results and policy implications than separate collection intentions in China. Accordingly, the government should provide a pro-environmental climate, convenient facilities, detailed cases, cultivate environmental moral obligations and propose appropriate promotional and incentive policies for different recycling modes.

The Clean Development Mechanism (CDM) is one of the “flexibility mechanisms” defined in the Kyoto Protocol to deal with global climate change. This paper uses the event study methodology to determine the relationship between corporate CDM adoption and financial performance. We conjecture that implementing CDM projects is beneficial for non-core business returns but not corporate profitability because firms often have an ulterior motive in obtaining direct economic revenue from CDM projects without expending due effort on environmental protection and efficiency improvement. We extract a list of companies with operational CDM projects in China and identify them as the sample group. Using the propensity score methodology, we establish a control group based on estimations using a probit regression model that verifies the factors determining industrial companies’ participation in CDM projects. The control group comprises non-adopters of CDM projects that have a similar propensity score to CDM adopters based on their corporate financial indicators. The results from Wilcoxon signed-rank tests and one-sample binomial tests show that the major positive financial effect of CDM adoption is obtained from the growth of non-core business revenue. The profitability of the adopters is not significantly changed after the CDM adoption. There are no remarkable changes in sales growth after CDM certification.

Sodium alginate (SA) is investigated as the aqueous binder to fabricate high-performance, low-cost, environmentally friendly, and durable TiO2 anodes in sodium-ion batteries (SIBs) for the first time. Compared to the conventional polyvinylidene difluoride (PVDF) binder, electrodes using SA as the binder exhibit significant promotion of electrochemical performances. The initial Coulombic efficiency is as high as 62% at 0.1 C. A remarkable capacity of 180 mAh g–1 is achieved with no decay after 500 cycles at 1 C. Even at 10 C (3.4 A g–1), it remains 82 mAh g–1 after 3600 cycles with approximate 100% Coulombic efficiency. TiO2 electrodes with SA binder display less electrolyte decomposition, fewer side reactions, high electrochemistry reaction activity, effective suppression of polarization, and good electrode morphology, which is ascribed to the rich carboxylic groups, high Young’s modulus, and good electrochemical stability of SA binder.