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Extraction of uranium from seawater is critical for the sustainable development of nuclear energy. However, the currently available uranium adsorbents are hampered by co-existing metal ion interference. DNAzymes exhibit high selectivity to specific metal ions, yet there is no DNA-based adsorbent for extraction of soluble minerals from seawater. Herein, the uranyl-binding DNA strand from the DNAzyme is polymerized into DNA-based uranium extraction hydrogel (DNA-UEH) that exhibits a high uranium adsorption capacity of 6.06 mg g −1 with 18.95 times high selectivity for uranium against vanadium in natural seawater. The uranium is found to be bound by oxygen atoms from the phosphate groups and the carbonyl groups, which formed the specific nano-pocket that empowers DNA-UEH with high selectivity and high binding affinity. This study both provides an adsorbent for uranium extraction from seawater and broadens the application of DNA for being used in recovery of high-value soluble minerals from seawater. The extraction of metals from seawater is an area of great potential; especially for the extraction of uranium. Here, the authors report on the synthesis of a DNA based uranium adsorbent with high selectivity and demonstrate the potential for the DNA based extraction of high-value soluble minerals from seawater.

In order to increase the toughness of poly(hexamethylene furandicarboxylate) (PHF) without severely compromising its strength at break, novel biobased poly(hexamethylene furandicarboxylate-co-hexamethylene thiophenedicarboxylate) (PHFTh) copolyesters and their parent homopolyesters, PHF and poly(hexamethylene thiophenedicarboxylate), were successfully synthesized through melt polycondensation in this research. Despite the variation in their compositions, all the PHFTh copolyesters exhibited excellent thermal stability. The PHFTh copolyesters were semicrystalline in nature, showing the lowest eutectic melting points and isodimorphism behaviors over the whole composition range. As the hexamethylene thiophenedicarboxylate (HTh) unit content increased, the glass transition temperature of the copolyesters gradually decreased, while the chain mobility was accordingly enhanced. Therefore, the introduction of the HTh unit significantly increased the elongation at break of the PHFTh, achieving a balance between strength and toughness. The biobased PHFTh copolyesters showed tunable thermal behaviors and excellent mechanical properties and may find potential end uses from a practical application viewpoint.

Coronal mass ejections (CMEs) and their associated shock waves have severe space weather effects in the near-Earth space. Therefore, predicting the propagation and arrival time of the CME/shock is an important component of the space weather forecast. In this work, the analytical solutions for the propagation of blast waves are reorganized and derived, and a novel solution is obtained to describe their propagation in the background flow field moving at a constant speed. This novel solution can be used to predict the propagation and arrival time of the CME-associated shock waves in both the coronal and interplanetary medium. The input parameters of this novel solution are the shock wave’s initial velocity, the piston-driving time in an analog of the initial blast process, and the background solar wind velocity. Based on the same initial conditions, we compare quantitatively the propagation processes of shock waves predicted by this novel solution and those predicted by other already existing models of the blast wave theory. The obtained results demonstrate the feasibility of this novel solution in predicting the arrival time of the interplanetary shock in the future.

Band alignment has been keeping fascinating because of its importance to the heterojunction interface for engineering the device performances. One of the most crucial parameters to determine band alignment is the charge neutrality level (CNL). In this study, we experimentally investigate the CNL modulation from the perspective of dipole formation at the GeO 2 /Al 2 O 3 interface and conduction band offset (CBO) tendency with Al 2 O 3 thicknesses after post-deposition annealing (PDA). The core level shift at the GeO 2 /Al 2 O 3 interface consists with the dipole change for the as-grown and N 2 PDA samples. The origin of dipole change after PDA is explained through CNL theory and band alignment. The CNL modulation is certified from the CBO dependence on the Al 2 O 3 thickness. The CBO at Ge/Al 2 O 3 hetero-interface decreases with Al 2 O 3 thickness for the as-grown sample and increases with Al 2 O 3 thickness after N 2 annealing. The CNL was experimentally estimated as 4.57 and 3.52 eV above the Al 2 O 3 valence band maximum for the as-grown and N 2 PDA samples. The CNL estimation is also consistent with the modulation change of dipole at the Al 2 O 3 /GeO 2 interface and CBO at Ge/Al 2 O 3 interface. This research may provide a feasible method of promoting device performance by modulating the CNL of dielectrics.

Coronal mass ejection (CME) is a powerful solar phenomenon that can lead to severe space weather events. Forecasting whether and when the corresponding interplanetary coronal mass ejection (ICME) will reach the Earth is very important in space weather study and forecast. At present, many different kinds of models use the near-Sun CME observations as model inputs to predict its propagation with similar prediction accuracies for large sample events. Among a series of physics-based models, the best-performing version of the shock propagation model (SPM) for large sample events, i.e., SPM3, had achieved a good forecast effect for the 23rd Solar Cycle events (1997.02–2006.12). To further evaluate SPM3, we collected CME events from 2013 January to 2023 July from the Community Coordinated Modeling Center (CCMC) CME scoreboard as a new data set. SPM3 achieved a total prediction success rate of 57% for these new events with a mean absolute error of 8.93 hr and a rms error of 10.86 hr for the shock's arrival time. Interestingly, SPM3 provided better predictions for the CME/shock events during high solar activity years than low solar activity years. We also analyzed the influence of input parameters on CME propagation and found that the larger the angular width of the CME event, the higher the probability of the corresponding IP shock's reaching the Earth. Source latitude had little effect on the arrival probability of the corresponding shock, while source longitude did. The CMEs originating from around W15° had the largest probability of hitting the Earth.

Since fast head-on coronal mass ejections and their associated shocks represent potential hazards to the space environment of the Earth and even other planets, forecasting the arrival time of the corresponding interplanetary shock is a priority in space weather research and prediction. Based on the radio spectrum observations of the 16-element array of the Daocheng Solar Radio Telescope (DSRT), the flagship instrument of the Meridian Project of China, during its construction, this study determines the initial shock speed of a type II solar radio burst on 2022 April 17 from its drifting speed in the spectrum. Assuming that the shock travels at a steady speed during the piston-driven phase (determined from the X-ray flux of the associated flare) and then propagates through interplanetary space as a blast wave, we estimate the propagation and arrival time of the corresponding shock at the orbit of the Solar Terrestrial Relations Observatory-A (STEREO-A). The prediction shows that the shock will reach STEREO-A at 14:31:57 UT on 2022 April 19. The STEREO-A satellite detected an interplanetary shock at 13:52:12 UT on the same day. The discrepancy between the predicted and observed arrival time of the shock is only 0.66 hr. The purpose of this paper is to establish a general method for predicting the shock’s propagation and arrival time from this example, which will be utilized to predict more events in the future based on the observations of ground-based solar radio spectrometers or telescopes like DSRT.

Coronal mass ejections (CMEs), as one of the most destructive solar activity phenomena, are the primary driver of extreme space weather events. Accurately predicting the probability and arrival time of the corresponding interplanetary CMEs and their associated shocks is crucial in space weather forecasting. Currently, the primary shock propagation prediction models mainly input the initial kinematic parameters of CMEs near the Sun. The physics-based Shock Propagation Model Version 3 (SPM3) has demonstrated a good forecasting performance for the CME/shock events from 2013 January to 2023 July. To further improve the prediction accuracy, this study incorporates the flux of solar energetic particles (SEPs). A composite index (I), constructed using principal component analysis, quantifies the combined influence of SEP and CME’s source longitude. The analysis reveals that SPM3 systematically underestimates the shock’s transit times when the I < 0.2 and VCME < 650 km s−1. For the events identified by these criteria, an empirical velocity-based bias correction is applied. Notably, the SEP flux data are specifically used to flag events where the correction is applied, rather than entering as a continuous predictor. The revised version SPM3v2 achieves a total prediction success rate of 61%, with mean absolute error and root mean square error reduced to 8.27 and 10.65 hr, outperforming the original SPM3.

Poly(propylene thiophenedicarboxylate) (PPTh) is a new type of fully biobased polyester with excellent thermal, mechanical, and barrier properties; however, its practical application has been seriously restricted by the relatively slow crystallization rate. To further improve the crystallization rate and broaden the potential application field of PPTh, PPTh/multi-walled carbon nanotubes (MWCNTs) composites were successfully synthesized via an in situ melt polycondensation process in this research. Low contents of MWCNTs were well dispersed in the PPTh matrix. MWCNTs significantly increased the melt crystallization temperature and isothermal crystallization rate of PPTh, indicating the effective heterogeneous nucleating agent role. PPTh/MWCNTs composites displayed the same crystal structure as PPTh. In addition, the introduction of MWCNTs significantly enhanced both the Young’s modulus and the tensile strength of PPTh. From a sustainable viewpoint, biobased PPTh/MWCNTs composites reported in this research were of significant importance and interest as they showed remarkably improved crystallization rates and mechanical properties.

Ground level enhancements (GLEs) are extreme solar energetic particle (SEP) events that are of particular importance in space weather. In solar cycle 24, two GLEs were recorded on 2012 May 17 (GLE 71) and 2017 September 10 (GLE 72), respectively, using a range of advanced modern instruments. Here we conduct a comparative analysis of the two events by focusing on the effects of large-scale magnetic field configuration near active regions on particle acceleration and release. Although the active regions are both located near the western limb, temporal variations of SEP intensities and energy spectra measured in situ display different behaviors at early stages. By combining a potential field model, we find the coronal mass ejection (CME) in GLE 71 originated below the streamer belt, while in GLE 72 it originated near the edge of the streamer belt. We reconstruct the CME shock fronts with an ellipsoid model based on nearly simultaneous coronagraph images from multiple viewpoints and further derive the 3D shock geometry at the GLE onset. The highest-energy particles are primarily accelerated in the shock–streamer interaction regions, i.e., likely at the nose of the shock in GLE 71 and the eastern flank in GLE 72, due to quasi-perpendicular shock geometry and confinement of closed fields. Subsequently, they are released to the field lines connecting to near-Earth spacecraft when the shocks move through the streamer cusp region. This suggests that magnetic structures in the corona, especially shock–streamer interactions, may have played an important role in the acceleration and release of the highest-energy particles in the two events.

PurposeChina has proposed two-stage goals of carbon peaking by 2030 and carbon neutralization by 2060. The carbon emission reduction effect of the power industry, especially the thermal power industry, will directly affect the progress of the goal. This paper aims to reveal the spatial-temporal characteristics and influencing factors of carbon emission efficiency of the thermal power industry and proposes policy suggestions for realizing China’s carbon peak and carbon neutralization goals.Design/methodology/approachThis paper evaluates and compares the carbon emission efficiency of the thermal power industry in 29 provinces and regions in China from 2014 to 2019 based on the three-stage slacks-based measure (SBM) of efficiency in data envelopment analysis (DEA) model of undesired output, excluding the influence of environmental factors and random errors.FindingsEmpirical results show that during the sample period, the carbon emission efficiency of China’s thermal power industry shows a fluctuating upward trend, and the carbon emission efficiency varies greatly among the provincial regions. The carbon emission efficiency of the interregional thermal power industry presents a pattern of “eastern > central > western,” which is consistent with the level of regional economic development. Environmental factors such as economic level and environmental regulation level are conducive to the improvement of carbon emission efficiency of the thermal power industry, but the proportion of thermal power generation and industrial structure is the opposite.Originality/valueThis paper adopts the three-stage SBM–DEA model of undesired output and takes CO2 as the undesired output to reveal the spatial-temporal characteristics and influencing factors of carbon emission efficiency in China’s thermal power industry. The results provide a more comprehensive perspective for regional comparative evaluation and influencing factors of carbon emission efficiency in China’s thermal power industry.