| 1. |
- Wang, K., et al.
(författare)
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Amended soils with weathered coal exhibited greater resistance to aggregate breakdown than those with biochar : From the viewpoint of soil internal forces
- 2024
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Ingår i: Soil & Tillage Research. - : Elsevier B.V.. - 0167-1987 .- 1879-3444. ; 244
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Tidskriftsartikel (refereegranskat)abstract
- Soil erosion is the first threat to soil functions. Reducing the soil aggregate breakdown strength is a key step to improve the soil's ability to resist rainfall splash erosion. Soil internal forces have been found to be the initial and important forces driving aggregate turnover. The application of exogenous organic materials can effectively improve soil aggregate stability and the resistance to rainfall erosion of agricultural soils. However, from the perspective of soil internal forces, information about the reduction effects of the exogenous organic materials application on soil aggregate breakdown is scarce, especially in comparing the effects of different materials. In this study, weathered coal and biochar were individually applied to loamy clay soil at rates of 0 %, 1 %, 2 %, and 3 % (w/w). Soil internal forces, aggregate breakdown strength, and splash erosion rate of different amended soils were then examined after four years. The results showed that compared with unamended soils (0 %), both weathered coal and biochar applications clearly increased the van der Waals attractive pressure and thus decreased the positive net pressure between soil particles. Additionally, these materials reduced soil aggregate breakdown strength and splash erosion rate. The application effects of the two materials were increased with their application rates. Under a lower electrolyte concentration in soil solution (0.0001 mol L−1), the aggregate breakdown strength in the soils amended with weathered coal was lower than that with biochar by 9.6 %, 23.2 %, and 17.7 % (when the diameter of broken aggregate was < 10 μm) and by 10.3 %, 20.8 %, and 17.5 % (when the diameter of broken aggregate was < 20 μm) at the 1 %, 2 %, and 3 % application rates, respectively (P < 0.05). Additionally, soils amended with weathered coal exhibited lower splash erosion rates compared to those amended with biochar, particularly at the higher application rate of 3 %. From the viewpoint of soil internal forces, weathered coal appears to be a suitable exogenous organic material for improving soil aggregate stability and anti-erosion ability during rainfall events. Our findings provide valuable insights into utilizing exogenous materials to improve soil resistance to rainfall splash erosion, assisting agricultural soil management in areas frequently affected by rainfall erosion.
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| 2. |
- Zhang, X., et al.
(författare)
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Greater mineral and aggregate protection for organic carbon in the soil amended by weathered coal than by biochar : Based on a 3-year field experiment
- 2023
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Ingår i: Geoderma. - : Elsevier B.V.. - 0016-7061 .- 1872-6259. ; 438
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Tidskriftsartikel (refereegranskat)abstract
- Soil carbon pool stability plays an important role in reaching carbon neutrality and mitigating global warming. Applying soil amendments is a practical strategy in agricultural production to improve soil environment. Weathered coal (WC) is an organic amendment that can be used to improve soil quality. However, the effects of WC application on soil organic carbon pool stability, and its differences from the effects of biochar (BC, a common amendment) application remains unclear. In this study, BC was selected as a comparison to further evaluate the potential of WC based on a 3-year field experiment, in which WC and BC were individually applied into a loamy clay soil at 0%, 1%, and 3% (w/w) rates. Soil organic carbon and its fractions (including particulate organic carbon and mineral-bound organic carbon), soil aggregate fractions and its stability, and the organic carbon content in aggregates were examined. The results showed that both WC and BC significantly increased soil total organic carbon, particulate and mineral-bound organic carbon (P < 0.05). The mineral-bound organic carbon content in WC treatment was significantly higher than that in BC treatment (by 32% under the 3% rate) (P < 0.05), whereas, there were no significant differences in soil total organic carbon content. Both WC and BC increased the soil organic carbon content in all aggregate fractions. While only the WC improved the soil aggregate stability, and which was 15% (under 1% rate) and 28% (under 3% rate) higher in WC treatments than in BC treatments (P < 0.05). The proportion of mineral-bound organic carbon to soil total organic carbon content and the soil aggregate stability were obviously related the soil C/N, and the WC treatments had a higher proportion of mineral-bound organic carbon and soil aggregate stability than BC treatments under the same soil C/N. The results indicated that the application of WC may be more effective than BC in increasing mineral and aggregate protection for soil organic carbon and thus improving soil carbon pool stability. Additionally, the purchase cost of WC was clearly lower than that of BC. Combined with the low cost and the benefits in soil structure and carbon pool stability, the application of WC appeared to have advantages over BC. Our findings provide robust evidence that WC is more effective than BC in improving soil carbon pool stability.
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| 3. |
- Du, J., et al.
(författare)
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A theory-guided deep-learning method for predicting power generation of multi-region photovoltaic plants
- 2023
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Ingår i: Engineering applications of artificial intelligence. - : Elsevier Ltd. - 0952-1976 .- 1873-6769. ; 118
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Tidskriftsartikel (refereegranskat)abstract
- Recently, clean solar energy has aroused wide attention due to its excellent potential for electricity production. A highly accurate prediction of photovoltaic power generation (PVPG) is the basis of the production and transmission of electricity. However, the current works neglect the regional correlation characteristics of PVPG and few studies propose an effective framework by incorporating prior knowledge for more physically reasonable results. In this work, a hybrid deep learning framework is proposed for simultaneously capturing the spatial correlations among different regions and temporal dependency patterns with various importance. The scientific theory and domain knowledge are incorporated into the deep learning model to make the predicted results possess physical reasonability. Subsequently, the theory-guided and attention-based CNN-LSTM (TG-A-CNN-LSTM) is constructed for PVPG prediction. In the training process, data mismatch and boundary constraint are incorporated into the loss function, and the positive constraint is utilized to restrict the output of the model. After receiving the parameters of the neural network, a TG-A-CNN-LSTM model, whose predicted results obey the physical law, is constructed. A real energy system in five regions is used to verify the accuracy of the proposed model. The predicted results indicate that TG-A-CNN-LSTM can achieve higher precision of PVPG prediction than other prediction models, with RMSE being 11.07, MAE being 4.98, and R2 being 0.94, respectively. Moreover, the performance of prediction models with sparse data is tested to illustrate the stability and robustness of TG-A-CNN-LSTM.
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| 4. |
- Huo, Jingwen, et al.
(författare)
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Drivers of fluctuating embodied carbon emissions in international services trade
- 2021
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Ingår i: One Earth. - : ELSEVIER. - 2590-3330 .- 2590-3322. ; 4:9, s. 1322-1332
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Tidskriftsartikel (refereegranskat)abstract
- Service industries are generally considered "green'' because of their marginal direct emissions; however, they account for 65% of the world gross domestic product and over 20% of total global trade in 2019. Here, we quantify the evolution of carbon emissions embodied in services trade from 2010 to 2018 and identify the driving factors of emission change at the global and regional scales. The annual growth rate of embodied emissions exported from the Global South (2.0%) is double that of the Global North (1.0%), with a different trade structure. We further identify three trade patterns of service export in the Global South based on the bilateral trade partnership and annual growth rate. Three kinds of specific emission mitigation policies are proposed based on the characters of services trade and different trade structures between different regions. The results provide quantitative evidence currently lacking and critical to policy decision making.
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| 5. |
- Li, Bojia, et al.
(författare)
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Evaluating the role of clean heating technologies in rural areas in improving the air quality
- 2021
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Ingår i: Applied Energy. - : ELSEVIER SCI LTD. - 0306-2619 .- 1872-9118. ; 289
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Tidskriftsartikel (refereegranskat)abstract
- The Air Pollution Prevention and Control Action Plan proposed in 2013 has contributed to the fossil fuel reduction in central heating, but the consumption of scattered coal in rural areas should not be overlooked as it accounts for nearly 50% pollutant emissions during the heating season. Air Pollution Prevention and Control Action Plan for Beijing-Tianjin-Hebei and Surrounding Areas was issued to solve the problem of scattered coal consumption and improve the heating energy structure in 2017. In this paper, an air quality-heating model is established to evaluate the air quality improvement potential and far-reaching influence of scattered coal consumption reduction in rural areas. Distinct from other air quality evaluation models, the proposed model is to evaluate the regional air quality related to the heating factors. The results indicate that the coal substitution policy can reduce PM2.5 concentrations in the heating season by about 20 mu g/m(3) in Beijing-Tianjin-Hebei and surrounding areas. Furthermore, predictions about the variation of PM2.5 concentration in the heating season are conducted, which indicate that the PM2.5 concentration of Beijing, Tianjin, Hebei and surrounding areas in 2030 will drop by 48%, 35%, 29% and 23% respectively compared to that in 2016. The reduction could be further enhanced to be 55%, 40%, 32% and 27% with the consideration of clean power development. This study is conducive to evaluate the clean heating technologies role in improving the environment and air quality.
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| 6. |
- Liu, Minzhang, et al.
(författare)
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The environment and energy consumption of a subway tunnel by the influence of piston wind
- 2019
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Ingår i: Applied Energy. - : ELSEVIER SCI LTD. - 0306-2619 .- 1872-9118. ; 246, s. 11-23
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Tidskriftsartikel (refereegranskat)abstract
- With the flourishing development of the subway construction, it becomes increasingly urgent to improve the subway tunnel environment and reduce the energy consumption of the tunnel ventilation system. The tunnel environment is significantly affected by the piston wind, which is influenced by the train speed. In this paper, a three-dimensional computational model of a subway tunnel is developed and validated through experiments. The model is used to study the carbon dioxide concentration and thermal environment of the subway tunnel. The optimal train speed is proposed with the aim to minimize the volume of mechanical supply air and to optimize the carbon dioxide concentration and thermal environment of the tunnel. In parallel with the considerations of tunnel environment, the subways in 25 cities of China are analyzed to study the energy conservation of the tunnel ventilation system by making full use of piston wind. The results indicate that the optimal train speed is 30 m/s based on the carbon dioxide concentration and thermal environment. The effective utilization of the piston wind can reduce 13% similar to 32% of the energy consumption for tunnel ventilation. The calculation method of the optimal train speed developed in this paper is also applicable to ordinary railway tunnels and high-speed railway tunnels.
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| 7. |
- Zhang, Chi, et al.
(författare)
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Five tips for China to realize its co-targets of climate mitigation and Sustainable Development Goals (SDGs)
- 2020
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Ingår i: Geography and Sustainability. - : Elsevier BV. - 2096-7438 .- 2666-6839. ; 1:3, s. 245-249
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Tidskriftsartikel (refereegranskat)abstract
- In 2018, a total of US$166 billion global economic losses and a new high of 55.3 Gt of CO2 equivalent emission were generated by 831 climate-related extreme events. As the world's largest CO2 emitter, we reported China's recent progresses and pitfalls in climate actions to achieve climate mitigation targets (i.e., limit warming to 1.52 degrees C above the pre-industrial level). We first summarized China's integrated actions (2015 onwards) that benefit both climate change mitigation and Sustainable Development Goals (SDGs). These projects include re-structuring organizations, establishing working goals and actions, amending laws and regulations at national level, as well as increasing social awareness at community level. We then pointed out the shortcomings in different regions and sectors. Based on these analyses, we proposed five recommendations to help China improving its climate policy strategies, which include: 1) restructuring the economy to balance short-term and long-term conflicts; 2) developing circular economy with recycling mechanism and infrastructure; 3) building up unified national standards and more accurate indicators; 4) completing market mechanism for green economy and encouraging green consumption; and 5) enhancing technology innovations and local incentives via bottom-up actions.
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| 8. |
- Zhang, Yang, et al.
(författare)
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Planning and operation of an integrated energy system in a Swedish building
- 2019
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Ingår i: Energy Conversion and Management. - : Elsevier. - 0196-8904 .- 1879-2227. ; 199
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Tidskriftsartikel (refereegranskat)abstract
- More flexibility measures are required due to the increasing capacities of variable renewable energies (VRE). In buildings, the integration of energy supplies forms integrated energy systems (IES). IESs can provide flexibility and increase the VRE penetration level. To upgrade a current building energy system into an IES, several energy conversion and storage components are needed. How to decide the component capacities and operate the IES were investigated separately in studies on system planning and system operation. However, a research gap exists that the system configuration from system planning is not validated by actual operation conditions in system operation. Meanwhile, studies on system operation assume that IES configurations are predetermined. This work combines system planning and system operation. The IES configuration is determined by mixed integer linear programming in system planning. Actual operation conditions and forecast errors are considered in system operation. The actual operation profiles are obtained through year-round simulations of different energy management systems. The results indicate that the system configuration from system planning can meet energy demands in system operation. Among different energy management systems, the combination of robust optimization and receding horizon optimization achieves the lowest yearly operation cost. Meanwhile, two scenarios that represent high and low forecast accuracies are studied. Under the high and low forecast accuracy scenarios, the yearly operation costs are about 4% and 6% higher than that obtained from system planning.
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