To explore effective schemes of reducing carbon emission at the city level, this study evaluate the decoupling situation and the driving forces of industrial carbon emission in a coastal city of Zhuhai, China. Macro and micro analyses of evolutions of energy consumption, carbon emission, and industrial added value were conducted from 2006 to 2016. Carbon emission was decomposed at the overall and subdivided industrial level by using the logarithmic mean division index method (LMDI) method. Results showed that the industrial added value emerges sustainable increase tendency. Both energy consumption and carbon emission keeps continuous increase during the 11th five year period (11-FYP). They firstly decrease and then they present volatile change during the rest years of the 12-FYP. Rigorous incentives should be enacted to avoid the phenomenon of carbon emission increase rebound during the later phase of each FYP. There are no decoupling signals during the whole 11-FYP. Strong decoupling started to emerge during the 12-FYP. On a micro level, the decoupling phenomenon enhanced with the extension of the evaluation cycle. Furthermore, the economic output value is the main driving force factor of carbon emission, and the energy intensity effect is the dominant driver for reducing the industrial carbon emission during the 11-FYP. For the 12-FYP, the conjunctive role of the industrial structure effect, the energy intensity effect, the energy mix effect, and carbon emission factor effect drives carbon emission mitigation.
Trip data that records each vehicle's trip activity on the road network describes the operation of urban traffic from the individual perspective, and it is extremely valuable for transportation research. However, restricted by data privacy, the trip data of individual-level cannot be opened for all researchers, while the need for it is very urgent. In this paper, we produce a city-scale synthetic individual-level vehicle trip dataset by generating for each individual based on the historical trip data, where the availability and trip data privacy protection are balanced. Privacy protection inevitably affects the availability of data. Therefore, we have conducted numerous experiments to demonstrate the performance and reliability of the synthetic data in different dimensions and at different granularities to help users properly judge the tasks it can perform. The result shows that the synthetic data is consistent with the real data (i.e., historical data) on the aggregated level and reasonable from the individual perspective.
Surface ground motion produced by underground blasts is significantly influenced by near-surface geological conditions. However, near-surface low-propagation velocity layers were always ignored in past analyses of ground motions due to their thin thickness. With the rising concern about surface ground motions produced by the ascendant scale and frequentness of underground excavation and mining, close attention is gradually paid to ground blast vibrations. Therefore, systemic experiments were conducted and took seven months in an underground mine to clarify the variation of motion from underground rock to surface ground. The attenuation of surface ground peak particle velocities (PPVs) is compared to that in underground rock, and horizontal amplitudes are compared to vertical amplitudes. Differences between bedrock and surface ground vibrations are analyzed to illustrate the site effect of near-surface lower-propagation velocity layers. One-dimensional site response analysis is employed to quantify the influence of different geological profiles on surface ground vibrations. The experimental data and site response analysis allowed the following conclusions: (1) geological site effects mainly produce decreasing dominant frequency (DF) of surface ground vibrations; (2) the site amplification effect of blast vibration needs to be characterized by peak particle displacement (PPD); (3) shear waves (S-waves) begin to dominate and surface Rayleigh waves (R-waves) develop as blast-induced ground vibrations travel upward through rock and lower-velocity layers to the surface. The comparison of response relative displacement to a critical value is best to assess the potential for cracking on surface structures.
As China is the largest greenhouse gas emitter and has the characteristics of significant regional disparity, the issue of regional low-carbon development strategy is of vital importance for the achievement of the country’s long-term emission targets. This work focused on China’s long-term carbon emission abatement from the perspective of regional disparity. We firstly analyzed the national emission trajectories consistent with the current Intended Nationally Determined Contributions (INDCs), 2 °C, and 1.5 °C goals in two economic growth pathways by 2050 using a linear programming model, then classified the provinces into three categories, and compared results of different scenarios of regional disparity patterns, economic growth rates, and emission targets. Results showed that different regional patterns led to different required carbon reduction targets for all categories, and the regional emission reduction measures had to be stronger in a higher growth rate or a more stringent emission target, especially for the developed areas. A scheme of regionally coordinated low-carbon development was then recommended for the formulation of long-term regional emission targets, and carbon reduction strategies for categories were proposed in terms of energy mix optimization, industrial transformation, and technology innovation, which is of great policy implication for China in regional development and national emission targets enhancement.