Finite Temperature Dynamics of Spin Solitons with Applications in Thermocouples and Refrigerators

The exploitation of spin Berry phases to generate emergent fields for producing miniaturized and high-quality inductors has enjoyed considerable popularity among proponents of quantum technologies [Nature 586, 202 (2020)}]. Inspired by this breakthrough, we extend its mechanism to spin thermoelectrics by probing responses of ferrimagnetic domain walls (DWs) to thermal gradients. Similarly, voltages here stem from DW-spin collective motion, in contrast to normal electron transport phenomena. We further develop finite-temperature dynamics to investigate thermoelectric figures of merit and attribute corresponding quantum superiority to ultrafast spin evolution of ferrimagnetism with tunable non-Abelian phases. We propose a more likely cause of DW motion towards hot or cold regions (contrary to conclusions of previous reports) and verify existence of efficient magnon-momentum transfers. These findings deepen our understanding of heat-driven DW kinetics and suggest profitable new directions in an emerging realm of spincaloritronics

Amiloride Enhances Antigen Specific CTL by Faciliting HBV DNA Vaccine Entry into Cells

The induction of relatively weak immunity by DNA vaccines in humans can be largely attributed to the low efficiency of transduction of somatic cells. Although formulation with liposomes has been shown to enhance DNA transduction of cultured cells, little, if any, effect is observed on the transduction of somatic tissues and cells. To improve the rate of transduction, DNA vaccine delivery by gene gun and the recently developed electroporation techniques have been employed. We report here that to circumvent requirement for such equipment, amiloride, a drug that is prescribed for hypertension treatment, can accelerate plasmid entry into antigen presenting cells (APCs) both in vitro and in vivo. The combination induced APCs more dramatically in both maturation and cytokine secretion. Amiloride enhanced development of full CD8 cytolytic function including induction of high levels of antigen specific CTL and expression of IFN-γ+perforin+granzymeB+ in CD8+ T cells. Thus, amiloride is a facilitator for DNA transduction into host cells which in turn enhances the efficiency of the immune responses

Isotopic Composition (δ¹⁵N and δ¹⁸O) of Urban Forests in Different Climate Types Indicates the Potential Influences of Traffic Exhaust and Relative Humidity

Previous studies have shown that climatic and anthropogenic factors influence the variations in the stable isotope signature of tree materials in an urban ecosystem. However, the responses of urban trees to various anthropogenic and precipitation interventions are unclear. To fill the research gap, the isotopic composition (δ15N and δ18O) and total nitrogen content of the soil-plant system of urban forests were measured, focusing on typical urban tree species (Populus tomentosa and Ficus virens). The research was done under various land uses in China’s Beijing and Shenzhen megacities (with different humidity conditions). The linear mixed-effect model revealed that the δ15N values in the leaves of roadside Ficus virens were significantly higher than those in urban park sites, away from the road (δ15N difference = 7.2‰). In contrast, Populus tomentosa leaves exhibited a non-significant difference (δ15N difference = −1.8‰). Further regression analysis revealed that the variations in δ15N in tree leaves could be attributed to the proximity to highways, suggesting the influence of vehicle exhaust on δ15N values in roadside trees. The linear mixed-effect model also revealed δ18O values significantly higher in Populus tomentosa leaves than in Ficus virens leaves. To assess the influence of humidity conditions on δ18O values in the leaves, the ratio of the atmospheric and intercellular vapor pressures (ea/ei) of tree canopies was estimated. The result revealed that the ea/ei of Ficus virens was significantly higher than for Populus tomentosa, ascribed to the variation in the humidity conditions of the two megacities. These results highlight that urban trees can potentially serve as bioindicators for atmospheric pollution and humidity. Our findings highlight the ecophysiological responses of urban forests related to N and O as they vary according to traffic exhaust and relative humidity. Consequently, they are potentially valuable indicators of urban atmospheric contamination, forming a nature-based solution for citizen welfare improvement

Land Subsidence Prediction Induced by Multiple Factors Using Machine Learning Method

In the Beijing Plain, land subsidence is one of the most prominent geological problems, which is affected by multiple factors. Groundwater exploitation, thickness of the Quaternary deposit and urban development and construction are important factors affecting the formation and development of land subsidence. Here we choose groundwater level change, thickness of the Quaternary deposit and index-based built-up index (IBI) as influencing factors, and we use the influence factors to predict the subsidence amount in the Beijing Plain. The Sentinel-1 radar images and the persistent scatters interferometry (PSI) were adopted to obtain the information of land subsidence. By using Google Earth Engine platform and Landsat8 optical images, IBI was extracted. Groundwater level change and thickness of the Quaternary deposit were obtained from hydrogeological data. Machine learning algorithms Linear Regression and Principal Component Analysis (PCA) were used to investigate the relationship between land subsidence and influencing factors. Based on the results obtained by Linear Regression and PCA, a suitable machine learning algorithm was selected to predict the subsidence amount in the Beijing Plain in 2018 through influencing factors. In this study, we found that the maximum subsidence rate in the Beijing Plain had reached 115.96 mm/y from 2016 to 2018. The land subsidence was serious in eastern Chaoyang and northwestern Tongzhou. In addition, the area where thickness of the Quaternary deposit reached 150–200 m was prone to more serious land subsidence in the Beijing Plain. In groundwater exploitation, the second confined aquifer had the greatest impact on land subsidence. Through Linear Regression and PCA, we found that the relationship between land subsidence and influencing factors was nonlinear. XGBoost was feasible to predict subsidence amount. The prediction accuracy of XGBoost on the subsidence amount reached 0.9431, and the mean square error was controlled at 15.97. By using XGBoost to predict the subsidence amount, our research provides a new idea for land subsidence prediction

Coupling Efficiency Assessment of Food–Energy–Water (FEW) Nexus Based on Urban Resource Consumption towards Economic Development: The Case of Shenzhen Megacity, China

The population aggregation and economic development caused by urbanization significantly influence the efficiency of urban resource consumption. However, the coupling interactions between crucial resource consumptions such as food, energy and water (FEW) and urbanization processes within highly urbanized areas has not been well-studied. In this study, we constructed an assessment framework for the coupling efficiency measurement of FEW resource consumptions in 10 administrative districts across Shenzhen megacity during 2012–2020, based on the data envelopment analysis (DEA). This study demonstrated that, from the perspective of the FEW nexus, increasing efficiencies in the energy consumption of most districts improved the municipal FEW efficiency, while more than half of the districts did not achieve water resource efficiencies throughout the period. Concerning regional economic development, 80% of the districts improved coupling FEW efficiencies by 2020, the average values of which were higher for Yantian, Nanshan, Luohu and Dapeng, and lower for Baoan, Longgang and Guangming, with a downtrend only being observed in Guangming. Overall, the value of the coupling FEW efficiency of Shenzhen megacity rose by 35% from 2012 to 2020. Correlation analysis showed that synergistic effects of efficient resource consumption occurred in most districts, and economic urbanization was the main driving factor of regional FEW efficiencies within Shenzhen megacity. This study provides instructive insights into the status of urban resource consumption and suggests that the coordination of FEW management should be further improved by fiscal intervention to maintain economic development with the limited resources available, which would have valuable implications for synergistic FEW governance in megacities in China and elsewhere

Design of AUVs based on 3D coils positioning and distributed base station control for nuclear spent fuel pools

An underwater magnetic induction positioning and communication system and an energy-efficient distributed control algorithm for underwater base stations are proposed in this paper. The positioning and communication system consists of a number of base stations and an Autonomous Underwater Vehicle (AUV) equipped with three-axis source coils respectively. The AUV receives this signal and based on its amplitude and phase information is able to locate the AUV and communicate with the base station. Due to the short positioning distance of magnetic induction positioning technology, a large number of base stations need to be installed underwater, which puts high demands on the control of the base stations. In this paper, an energy-efficient distributed control algorithm for underwater base stations is proposed to enable the AUV to meet the operational requirements while minimizing the total energy consumption of the base station. According to the simulation results, the design solves the problem that traditional underwater positioning and communication equipment cannot work stably for long periods of time in a high radiated environment, with a positioning error of no more than 10 cm within a preset operating range, and the algorithm proposed in this paper is able to reduce energy wastage by about 20%

Combined GRACE and MT-InSAR to Assess the Relationship between Groundwater Storage Change and Land Subsidence in the Beijing-Tianjin-Hebei Region

Beijing-Tianjin-Hebei (BTH) has been suffering from severe groundwater storage (GWS) consumption and land subsidence (LS) for a long period. The overexploitation of groundwater brings about severe land subsidence, which affects the safety and development of BTH. In this paper, we utilized multi-frame synthetic aperture radar datasets obtained by the Rardarsat-2 satellite to monitor land subsidence’s temporal and spatial distribution in the BTH from 2012 to 2016 based on multi-temporal interferometric synthetic aperture radar (MT-InSAR). In addition, we also employed the Gravity Recovery and Climate Experiment (GRACE) mascon datasets acquired by the Center for Space Research (CSR) and Jet Propulsion Laboratory (JPL) to obtain the GWS anomalies (GWSA) of BTH from 2003 to 2016. Then we evaluate the accuracy of the results obtained. Furthermore, we explored the relationship between the regional GWSA and the average cumulative subsidence in the BTH. The total volume change of subsidence is 59.46% of the total volume change of groundwater storage. Moreover, the long-term decreasing trend of the GWSA (14.221 mm/year) and average cumulative subsidence (17.382 mm/year) show a relatively high consistency. Finally, we analyze the heterogeneity of GWS change (GWSC) and LS change (LSC) in the four typical areas by the Lorenz curve model. The implementation of the South-to-North Water Diversion Project (MSWDP) affects the heterogeneity of GWSC and LSC. It can be seen that the largest heterogeneity of LSC lags behind the GWSC in the Tianjin-Langfang-Hengshui-Baoding area. The largest uneven subsidence in Beijing and Tianjin occurred in 2015, and the largest uneven subsidence in Hengshui-Baoding occurred in 2014. After that, the heterogeneity of subsidence gradually tends to stable

Assessing Land Subsidence-Inducing Factors in the Shandong Province, China, by Using PS-InSAR Measurements

Shandong Province (SDP) experienced serious land subsidence from March 2017 to December 2020. Exploring the response relationships between land subsidence and its inducing factors plays an important role in ensuring the development of the economy and residential safety. Firstly, we applied Persistent Scatterers Interferometric Aperture Radar (PS-InSAR) technology to 558 Sentinel-1 images to determine the land subsidence in SDP from March 2017 to December 2020. Secondly, we mosaicked the land subsidence monitoring results of five tracks to obtain a land subsidence map covering the whole SDP and validated the land subsidence monitoring results using Global Positioning System (GPS) monitoring results and leveling benchmark monitoring results observed in the same period. Finally, the response relationships between the land subsidence and its inducing factors in SDP were analyzed. The findings are as follows: (1) the PS-InSAR outcomes showed that the land subsidence was widely distributed in SDP and that the maximum land subsidence rate was −298.9 mm/year during the study period. (2) The PS-InSAR monitoring results coincide well with the GPS monitoring results and leveling benchmark monitoring results; the Pearson correlation coefficient (PCC) values between the PS-InSAR monitoring results and the GPS measurement results and leveling benchmark monitoring results were 0.97 and 0.98, respectively. We found that Spearman’s rank correlation coefficient (SRCC) values between any two adjacent tracks of the mosaic PS-InSAR monitoring results were greater than 0.95, indicating good consistency. (3) The long-term overexploitation of groundwater in middle and deep aquifers and mining of underground mineral resources are the main inducing factors of land subsidence in SDP when considering this problem on a large geographical scale. Moreover, the type of bridge material is an important inducing factor causing the large variation in the land subsidence of the bridge body within a small geographical range. These findings may provide scientific support for land subsidence control measures in SDP

Assessing Land Subsidence-Inducing Factors in the Shandong Province, China, by Using PS-InSAR Measurements

Shandong Province (SDP) experienced serious land subsidence from March 2017 to December 2020. Exploring the response relationships between land subsidence and its inducing factors plays an important role in ensuring the development of the economy and residential safety. Firstly, we applied Persistent Scatterers Interferometric Aperture Radar (PS-InSAR) technology to 558 Sentinel-1 images to determine the land subsidence in SDP from March 2017 to December 2020. Secondly, we mosaicked the land subsidence monitoring results of five tracks to obtain a land subsidence map covering the whole SDP and validated the land subsidence monitoring results using Global Positioning System (GPS) monitoring results and leveling benchmark monitoring results observed in the same period. Finally, the response relationships between the land subsidence and its inducing factors in SDP were analyzed. The findings are as follows: (1) the PS-InSAR outcomes showed that the land subsidence was widely distributed in SDP and that the maximum land subsidence rate was −298.9 mm/year during the study period. (2) The PS-InSAR monitoring results coincide well with the GPS monitoring results and leveling benchmark monitoring results; the Pearson correlation coefficient (PCC) values between the PS-InSAR monitoring results and the GPS measurement results and leveling benchmark monitoring results were 0.97 and 0.98, respectively. We found that Spearman’s rank correlation coefficient (SRCC) values between any two adjacent tracks of the mosaic PS-InSAR monitoring results were greater than 0.95, indicating good consistency. (3) The long-term overexploitation of groundwater in middle and deep aquifers and mining of underground mineral resources are the main inducing factors of land subsidence in SDP when considering this problem on a large geographical scale. Moreover, the type of bridge material is an important inducing factor causing the large variation in the land subsidence of the bridge body within a small geographical range. These findings may provide scientific support for land subsidence control measures in SDP