Electron-magnon Umklapp Scattering in FePt Films Measured by Thermopower

We report unconventional thermopower (Seebeck coefficient, $S$) behavior of $L1_{0}$ FePt films. The electron diffusion and magnon scattering are found to be the major contributions to the thermopower at low temperatures. The temperature dependence of $S$ is fitted by a phenomenological expression. The extracted electron diffusion coefficient is positive, instead of negative for conventional metals. An overall concave curvature of the Fermi surface specific to FePt is found to be responsible. More interestingly, the magnon drag coefficient carries an opposite sign to that of electron diffusion, suggesting dominant contribution from electron-magnon umklapp scattering. DFT calculations identify several bands crossing the Brillouin zone boundaries, facilitating the umklapp process. The large spin-orbit coupling in FePt results in strong mixing of majority and minority spins among two of those bands, greatly enhancing the electron-magnon scattering.Comment: This paper has been withdrawn by the authors due to a measurement erro

Assessing the value of urban green infrastructure ecosystem services for high-density urban management and development:Case from the capital core area of Beijing, China

Urban green infrastructure (UGI) includes green and blue open spaces that provide multiple ecosystem services (ES) and the ecological and cultural benefits for people to hedge the urbanization challenges. In this paper, we assessed the total economic value of ES provided by UGI in the capital core area of Beijing by calculating the value of six types of ES related to high-density urban features: (1) climate regulation, (2) carbon sequestration and oxygen production, (3) water control and conservation, (4) air pollution reduction, (5) noise reduction (6) cultural services through the combination of replacement cost, carbon tax, shadow project, afforestation cost, and market price methods. The results showed that UGI generated economic benefits in the surveyed area of about CNY ¥1.56 billion (USD $240 million) per year or CNY ¥91.76 (USD$14) per capita. The largest share of ES came from carbon sequestration and oxygen production, amounting to about 46.32% of the total ES value. Our findings also revealed that the distribution of ES value patterns varied across communities. This study enhanced the understanding of local UGI and had significant policy implications for future urban sustainable management, both in the capital core area of Beijing and in other high-density urban areas

Application of Magnetic Integrated Technology in Controllable Reactor of Transformer Type

There is the magnetic coupling among control windings of controllable reactor of transformer type (CRT), the decoupling integrated magnetic technology is applied to the structure design of CRT in this paper. To realize the decoupling among the control windings we propose a magnetic integrated structure of CRT by providing low magnetic resistance magnetic circuit for control windings magnetic flux. The winding leakages of this structure are calculated, its inductance-transformer equivalent circuit is also established, and the equation of the coupling degree of control windings and no-load current with the lateral column air gap size are deduced. The simulation model for a CRT is fabricated with MATLAB/SIMULINK. Simulation and analysis results shows that when increasing the air gap, the magnetic coupling between the control windings decreases apparently, the utilization ratio of windings current is also raised. The simulation results verify the effectiveness of this method by controlling the lateral column air gap size to achieve the purpose of decoupling

From land to sea:Hydrological source tracking of microplastics in coastal sediments

Land-based sources are the predominant contributors to marine microplastic pollution; however, identifying specific inland origins and their correspondence transport paths remain challenging at large-scale. In Denmark, terrestrial-marine connectivity is largely mediated by a complex network of streams, that further complicates hydrological connections between diverse inland discharges and the final coastal receptor. This study presents a GIS-based hydrological source tracking approach to identify the relevant inland discharges and further delineating their transportation paths for microplastics (≥10 μm) sampled from coastal sediments. After analyzed with Focal Plane Array-based Fourier Transform Infrared (FPA-μFTIR) imaging, samples from 13 Danish coastal monitoring stations were tested for souce tracking operations. The tracking tool first screened the stream network across Denmark to identify both point and non-point inland sources—stormwater runoff, wastewater effluent, and combined sewer overflow (CSO)—contributing microplastics to the selected coastal zones. Microplastics were detected at all stations, with variations in abundance, polymer composition, particle shape, and size. Significant positive correlations (p < 0.05) were observed between discharge volume and the composition of certain microplastics: wastewater effluent positively correlates with fiber and polyvinylchloride (PVC), while stormwater-associated discharges (including CSOs) correlated with polypropylene (PP). However, total microplastic concentration was not significantly linked to the discharges. Nevertheless, the GIS-based hydrological tool demonstrated an early-screening tool to identify inland source of marine microplastics. The results underscored the significant role of inland discharges in transporting distinct microplastics to coastal environment, offering valuable insights for authorities to further implement more targeted hydrodynamic modelling, source-specific mitigation strategies, as well as optimised station deployment strategies in future

Heterogeneous dynamic correlation research among industrial structure distortion, two-way FDI and carbon emission intensity in China

The increase in carbon emissions year by year poses a severe challenge to the high-quality development and sustainability of China’s economy. How to reduce the intensity of carbon emissions has become a prominent issue to promote green growth. Based on the provincial panel data from 2011 to 2020, this paper uses Exploratory Spatial Data Analysis (ESDA), the spatial econometric model and intermediary effect test as analysis methods. The following results are drawn. Firstly, China’s industrial structure distortion index shows a downward trend. The industrial structure distortion index is the highest in the west of China, followed by the middle of China and is the lowest in the east of China. Secondly, the distortion of the industrial structure will not only lead to the increase in local carbon emission intensity but also produce reverse spillover to adjacent areas. Thirdly, the results of intermediary effect analysis show that industrial structure distortion can affect the transmission mechanism of carbon emission intensity by affecting two-way FDI. This paper has a profound practical significance for promoting the process of industrial upgrading by insisting on developing foreign trade to achieve carbon emission reduction. The main innovation of this paper is to put forward the concept of industrial structure distortion and bring it into a unified research framework with two-way FDI and carbon emission intensity

Complementarity problems, variational inequalities and extended lorentz cones

In this thesis, we introduced the concept of extended Lorentz cones. We discussed the solvability of variational inequalities and complementarity problems associated with an unrelated closed convex cone. This cone does not have to be an isotone projection cone. We showed that the solution of variational inequalities and complementarity problems can be reached as a limit of a sequence defined in an ordered space which is ordered by extended Lorentz cone. Moreover, we applied our results in game theory and conic optimization problems. We also discussed the positive operators. We showed necessary and sufficient conditions under which a linear operator is a positive operator of extended Lorentz cone. We also showed sufficient and necessary conditions under which a linear operator in a specific form is a positive operator

Decline curve analysis for multiple-fractured horizontal wells in tight oil reservoirs

        The production of multiple-fractured horizontal wells (MFHW) in tight oil reservoirs decreases rapidly in the initial period. It then enters a stable state of the low production with a slow loss-ratio. Because of its complicated production dynamic characteristics, the conventional rate-decline analysis method is no longer applicable. We adopt the semi- analytical solution of the MFHW five-region linear flow model to get the multiple-fractured dimensionless rate-decline analysis curves and continuously calculate the loss-ratio of the decline curves. Based on the characteristics of the loss-ratio in the log-log plot, the decline curve analysis (DCA) model for tight oil MFHW is established. According to the DCA model, dimensionless production decline curves are obtained, and the sensitivity of the parameters in the model is analyzed. Finally, the DCA model is used to analyze the production rate decline of tight oil MFHW, and good matching results and production forecasts are achieved. This method provides a scientific basis for the rate-decline analysis of tight oil MFHW.Cited as: Xu, G., Yin., H., Yuan, H., Xing, C. Decline curve analysis for multiple-fractured horizontal wells in tight oil reservoirs. Advances in Geo-Energy Research, 2020, 4(3): 296-304, doi: 10.46690/ager.2020.03.0