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This study aims to explore the application of fractional order chaotic system (FOCS), based on the T-S fuzzy model, in the design of secure communication (SC) and this SC system’s role in the construction of efficiency evaluation system for dispatching operation of energy saving and power generation under a low carbon economy (LCE). First, the definition of fractional order differential equations and the stability theory of FOCS are discussed. T-S fuzzy control is introduced to analyse the stability of FOCS. Then, based on the adaptive synchronisation theory, the combined FOCS is designed for SC, and the performance of the system constructed here is analysed in a MATLAB environment. Next, an evaluation index system of the dispatching operation effect of energy saving and power generation under LCE is constructed. The confidential communication system constructed here is used to transmit the index data. The particle swarm optimisation (PSO) algorithm is then used to optimise the back propagation neural network (BPNN) model. The BPNN algorithm based on PSO (PSO-BPNN) is obtained, and the evaluation model is constructed. After training this model, it is applied to the evaluation of the dispatching operation effect for energy saving and power generation in 10 provinces in China. The simulation results show that the FOCS based on the T-S fuzzy model can acquire the criterion of system stability. Furthermore, the constructed SC system can effectively undertake the secure transmission of square and sine waves. The performance of the PSO-BPNN model seems to be better than other algorithms. After analysing the data on energy saving and power generation from 10 provinces in China using this model, the comprehensive evaluation value of province 5 is found to be the highest and good (0.802), while that of province 4 is the lowest and general (0.600). Summarising, the FOCS based on T-S fuzzy model constructed here is applied to the design of SC. This can improve the confidentiality of data transmission and reduce the transmission error. Moreover, the BPNN evaluation model based on PSO can effectively achieve the evaluation of the dispatching operation effect of energy saving and power generation under LCE.

There are substantial differences in carbon footprints across households. This study applied an environmentally extended multiregional input–output approach to estimate household carbon footprints for 12 different income groups of China’s 30 regions. Subsequently, carbon footprint Gini coefficients were calculated to measure carbon inequality for households across provinces. We found that the top 5% of income earners were responsible for 17% of the national household carbon footprint in 2012, while the bottom half of income earners caused only 25%. Carbon inequality declined with economic growth in China across space and time in two ways: first, carbon footprints showed greater convergence in the wealthier coastal regions than in the poorer inland regions; second, China’s national carbon footprint Gini coefficients declined from 0.44 in 2007 to 0.37 in 2012. We argue that economic growth not only increases income levels but also contributes to an overall reduction in carbon inequality in China.

As a relatively mature technology, biomass molded fuel (BMF) is widely used in distributed and centralized heating in China and has received considerable government attention. Although many BFM incentive policies have been developed, decreased domestic traditional fuel prices in China have caused BMF to lose its economic viability and new policy recommendations are needed to stimulate this industry. The present study built a regionalized net present value (NPV) model based on real production process simulation to test the impacts of each policy factor. The calculations showed that BMF production costs vary remarkably between regions, with the cost of agricultural briquette fuel (ABF) ranging from 86 US dollar per metric ton (USD/t) to 110 (USD/t), while that of woody pellet fuel (WPF) varies from 122 USD/t to 154 USD/t. The largest part of BMF’s cost composition is feedstock, which accounts for up 50%–60% of the total; accordingly a feedstock subsidy is the most effective policy factor, but in consideration of policy implementation, it would be better to use a production subsidy. For ABF, the optimal product subsidy varies from 26 USD/t to 57 USD/t among different regions of China, while for WPF, the range is 36 USD/t to 75 USD/t. Based on the data, a regional BMF development strategy is also proposed in this study.

Variable Nozzle Turbocharger (VNT) was invented to solve the problem of matching an ordinary turbocharger with an engine. VNT can harness exhaust energy more efficiently, enhance intake airflow response and reduce engine emissions, especially during transient operating conditions. The difficulty of VNT control lies in how to regulate the position of the nozzle at different engine working conditions. The control strategy designed in this study is a combination of a closed-loop feedback controller and an open-loop feed-forward controller. The gain-scheduled proportional-integral-derivative (PID) controller was implemented as the feedback controller to overcome the nonlinear characteristic. As it is difficult to tune the parameters of the gain-scheduled PID controller on an engine test bench, system identification was used to identify the plant model properties at different working points for a WP10 diesel engine on the test bench. The PID controller parameters were calculated based on the identified first-order-plus-dead-time (FOPDT) plant model. The joint simulation of the controller and the plant model was performed in Matlab/Simulink. The time-domain and frequency-domain performances of the entire system were evaluated. The designed VNT control system was verified with engine tests. The results indicated that the real boosting pressure traced the target boosting pressure well at different working conditions.

This paper presents the Gompertz function of per capita GDP and vehicle stock to forecast the vehicle ownership of China through to 2050 against a background of increasing energy use and CO2 emissions associated with the potential demands of on-road vehicles. We forecast the level of vehicle stock in China based on the extant patterns of vehicle development in Organisation for Economic Co-operation and Development (OECD) countries, Europe, the United States and Japan. The results show that the OECD pattern and European pattern are more suitable for describing China’s vehicle stock growth when compared with Japanese and U.S. patterns. The study finds that China’s vehicle stock has developed as an S-shaped curve. During the forecast period, the inflection point of the increasing curve appears around the year 2030, with the annual growth of vehicle ownership increasing from 6.13% to 9.50% in the prior period prior and subsequently dropping to 0.45% in 2050. Based on the sensitivity analysis and robustness check, the impact of different Gompertz curve parameters and GDP growth rates on vehicle stock projection are analyzed.

The Chinese government has grown increasingly invested in ecology in recent years. This paper discusses eco-efficiency using data envelopment analysis on 48 cities in Bohai Rim with special focus on the role of industrial structure upgrades. Based on the values from a super undesirable slack-based model, this study investigates eco-efficiency from temporal and spatial perspectives to reveal gaps among Bohai cities but an overall improvement in regional eco-efficiency. Moreover, this study adopts the Global and Local Moran's I to identify positive spatial autocorrelations and shows that most cites in Bohai Rim have high-high, low-low aggregation characteristics. Plus, the economic effects of per capita GDP, industrial structure upgrades on eco-efficiency are determined according to a spatial Durbin model. There appear to be negative spillover effects of industrial structure upgrades on surrounding cities, which reflects an industry transfer phenomenon related to eco-efficiency.

Abstract The increasing discrepancy between on-road and type-approval fuel consumption for LDPVs (light-duty passenger vehicles) has attracted tremendous attention. We measured on-road emissions for 60 LDPVs in three China's cities and calculated their fuel consumption and CO2 (carbon dioxide) emissions. We further evaluated the impacts of variations in area-averaged speed on relative fuel consumption of gasoline LDPVs for the UAB (urban area of Beijing). On-road fuel consumption under the average driving pattern is 10 ± 2% higher than that normalized to the NEDC (new European driving cycle) cycle for all tested vehicles, and the on-road NEDC-normalized fuel consumption is higher by 30 ± 12% compared to type-approval values for gasoline vehicles. We observed very strong correlations between relative fuel consumption and average speed. Traffic control applied to LDPVs driving within the UAB during weekdays can substantially reduce total fleet fuel consumption by 23 ± 5% during restriction hours by limiting vehicle use and improving driving conditions. Our results confirmed that a new cycle for the type approval test for LDPVs with more real-world driving features is of great necessity. Furthermore, enhanced traffic control measures could play an important role in mitigating real-world fuel consumption and CO2 emissions for LDPVs in China.

Abstract Nickel is playing a pivotal role in development of modern infrastructure and technology with major applications such as stainless steel, alloy, rechargeable batteries and electroplating. Rapid industrial development and economic growth of China has accelerated the depletion of natural resource pools since recent three decades. Therefore, this study was performed to examine the evolution of substance flow of nickel. Main findings include the following: 1) China is being confronted the increasing risk of uncontrolled importation; 2) The consumption amount has been constantly extended up to 1010 Gg in 2015, however the obsolescence amount is almost remained at an unchanged range of 45–50 Gg; 3) If more nickel has been stocked in the consumption stage and landfill plants, only 30% is recycled. The obtained results implied that China should not only find more sources of imported minerals, but also there should be an enhancement of the urban mining for nickel resources in the circular economy field.