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Inverted planar perovskite solar cells offer opportunities for a simplified device structure compared with conventional mesoporous titanium oxide interlayers. However, their lower open-circuit voltages result in lower power conversion efficiencies. Using mixed-cation lead mixed-halide perovskite and a solution-processed secondary growth method, Luo et al. created a surface region in the perovskite film that inhibited nonradiative charge-carrier recombination. This kind of solar cell had comparable performance to that of conventional cells. Science , this issue p. 1442 High open-circuit voltages were achieved for planar perovskite solar cells by creating a graded junction. The highest power conversion efficiencies (PCEs) reported for perovskite solar cells (PSCs) with inverted planar structures are still inferior to those of PSCs with regular structures, mainly because of lower open-circuit voltages ( V oc ). Here we report a strategy to reduce nonradiative recombination for the inverted devices, based on a simple solution-processed secondary growth technique. This approach produces a wider bandgap top layer and a more n-type perovskite film, which mitigates nonradiative recombination, leading to an increase in V oc by up to 100 millivolts. We achieved a high V oc of 1.21 volts without sacrificing photocurrent, corresponding to a voltage deficit of 0.41 volts at a bandgap of 1.62 electron volts. This improvement led to a stabilized power output approaching 21% at the maximum power point.

This paper mainly investigates the influence of initiation mode and structural parameters of composite charge on detonation waveform and kinetic energy conversion efficiency of driving shell. The simulation was carried out by using AUTODYN software. The results provided the detonation waveform and the final kinetic energy of the shell under different charge structure parameters and initiation mode, and the kinetic energy conversion efficiency from the initial energy of the composite charge to the kinetic energy of the shell was calculated. The orthogonal optimization method is used to study and analyze the kinetic energy and kinetic energy conversion efficiency of the shell with three factors and each level, and the best parameter combination scheme is obtained. The three factors are the detonation velocity matching relationship between the inner and outer explosives of the composite charge, the initiation mode and the loading ratio of the inner and outer explosives. From the perspective of detonation waveform, the results show that when the inner layer is high detonation velocity explosive and the outer layer is low detonation velocity explosive, the detonation waveform is convex wave. On the contrary, under the explosive matching relationship of low detonation velocity in the inner layer and high detonation velocity in the outer layer, the detonation waveform is concave wave. From the perspective of the kinetic energy conversion efficiency of the shell, the results show that the kinetic energy conversion efficiency of the shell is the largest under the charge structure with the inner layer of low detonation velocity explosive and the outer layer of high detonation velocity explosive, loading ratio of the inner and outer explosives is 0.25 and the initiation mode is the initiation of the center point at the bottom of both ends. The research results can provide support for the design of composite charge structure.

Aiming at the problem of indoor environment, signal non-line-of-sight propagation and other factors affect the accuracy of indoor locating, an algorithm of indoor fingerprint localization based on the eight-neighborhood template is proposed. Based on the analysis of the signal strength of adjacent reference points in the fingerprint database, the methods for the eight-neighborhood template matching and generation were studied. In this study, the indoor environment was divided into four quadrants for each access point and the expected values of the received signal strength indication (RSSI) difference between the center points and their eight-neighborhoods in different quadrants were chosen as the generation parameters. Then different templates were generated for different access points, and the unknown point was located by the Euclidean distance for the correlation of RSSI between each template and its coverage area in the fingerprint database. With the spatial correlation of fingerprint data taken into account, the influence of abnormal fingerprint on locating accuracy is reduced. The experimental results show that the locating error is 1.0 m, which is about 0.2 m less than both K-nearest neighbor (KNN) and weighted K-nearest neighbor (WKNN) algorithms.

Hybrid lead halide perovskites have emerged as high-performance photovoltaic materials with their extraordinary optoelectronic properties. In particular, the remarkable device efficiency is strongly influenced by the perovskite crystallinity and the film morphology. Here, we investigate the perovskites crystallisation kinetics and growth mechanism in real time from liquid precursor continually to the final uniform film. We utilize some advanced in situ characterisation techniques including synchrotron-based grazing incident X-ray diffraction to observe crystal structure and chemical transition of perovskites. The nano-assemble model from perovskite intermediated [PbI 6 ] 4− cage nanoparticles to bulk polycrystals is proposed to understand perovskites formation at a molecular- or nano-level. A crystallisation-depletion mechanism is developed to elucidate the periodic crystallisation and the kinetically trapped morphology at a mesoscopic level. Based on these in situ dynamics studies, the whole process of the perovskites formation and transformation from the molecular to the microstructure over relevant temperature and time scales is successfully demonstrated. The photovoltaic performances of perovskite materials are strongly influenced by their crystallinity and film morphology. Here, the authors investigate the formation and morphology evolution mechanisms of lead halide perovskites and reveal that bulk polycrystals grow from intermediate [PbI6] 4 − cage nanoparticles.

In order to study the detonation wave propagation process of the composite charge, the wavefront type, and the relationship between the characteristic parameter α of the composite charge wavefront and the detonation velocity difference of the inner and outer layer explosive. The finite element software was used to numerically simulate and calculate six structural schemes that changed the detonation velocity of the inner and outer layers explosive of the composite charge and the diameter ratio of the inner and outer explosives. The test results show that the composite charge structure with different inner and outer explosive detonation velocities and the diameter ratio of inner and outer explosives has different wavefront propagation processes and wavefront types. When the diameter ratio of the inner and outer explosives in the composite charge structure is the same, the detonation velocity difference between the inner and outer layers of explosives is changed, and the influence law of the incident Angle changes with the change of the detonation velocity difference is found.

Interfacial molecules have been demonstrated to improve the photovoltaic performance of perovskite solar cells (PSCs). However, the effect is influenced by the targeted substrate and, in particular, by its bond with the interfacial molecule. A weaker bonding of the interfacial molecule with the substrate usually implies a stronger bonding with the perovskite that could lead to uncontrollable insertion of the interfacial molecule into the perovskite bulk, resulting in device degradation. Here we select bis(2-aminoethyl) ether (BAE) as the interfacial molecule between the perovskite and the electron transport layer (ETL) in n–i–p PSCs and develop a strategy to harmonize the strength of the bilateral bonds of BAE. In particular, we manipulate the electronic structure of the ETL with doping to increase the strength of the BAE–ETL bond. This thereby results in a weakening of the BAE–perovskite bond. The harmonization in bilateral bonds of the interfacial molecule leads to PSCs with an efficiency surpassing 26.5% (certified as 26.31%) and improved stability. The interfaces in perovskite solar cells are critical to the device performance. Li et al. tune the bond strength of the interfacial molecule with the perovskite and the electron transport layer, increasing the power conversion efficiency of the cells.

Electroless silver (Ag) plating has emerged as a simple yet effective surface modification technique, garnering significant attention in consumer electronics and composite materials. This study systematically investigates the influence of glucose dosage on the microstructural refinement of Ag coatings deposited from silver–ammonia solutions onto iron (Fe) particles while also evaluating the oxidation resistance of Ag-plated particles through thermogravimetric analysis. Optimal results were achieved at a silver nitrate concentration of 0.02 mol/L and a glucose concentration of 0.05 mol/L, producing Fe particles with a uniform and dense silver coating featuring an average Ag grain size of 76 nm. The moderate excess glucose played a dual role: facilitating Ag+ ion reduction while simultaneously inhibiting the growth of Ag atomic clusters, thereby ensuring microstructural refinement of the silver layer. Notably, the Ag-plated particles demonstrated superior oxidation resistance compared to their uncoated counterparts. These findings highlight the significance of fine-grained electroless Ag plating in developing high-temperature conductive metal particles and optimizing interfacial structures in composite materials.

In the field of degradable metals, Zn-based implants have gradually gained more attention. However, the relatively slow degradation rate compared with the healing rate of the damaged bone tissue, along with the excessive Zn2+ release during the degradation process, limit the application of Zn-based implants. The use of intermetallic compounds with more negative electrode potentials as sacrificial anodes of Zn-based implants is likely to be a feasible approach to resolve this contradiction. In this work, three intermetallic compounds, MgZn2, CaZn13, and Ca2Mg6Zn3, were prepared. The phase structures, microstructures, and relevant properties, such as thermal stability, in vitro degradation properties, and cytotoxicity of the compounds, were investigated. The XRD patterns indicate that the MgZn2 and CaZn13 specimens contain single-phase MgZn2 and CaZn13, respectively, while the Ca2Mg6Zn3 specimen contains Mg2Ca and Ca2Mg6Zn3 phases. After purifying treatment in 0.9% NaCl solution, high purity Ca2Mg6Zn3 phase was obtained. Thermal stability tests suggest that the MgZn2 and CaZn13 specimens possess good thermal stability below 773 K. However, the Ca2Mg6Zn3 specimen melted at around 739.1 K. Polarization curve tests show that the corrosion potentials of MgZn2, CaZn13, and Ca2Mg6Zn3 in simulated body fluid (SBF) were −1.063 VSCE, −1.289 VSCE, and −1.432 VSCE, which were all more negative than that of the pure Zn specimen (−1.003 VSCE). Clearly, these compounds can act as sacrificial anodes in Zn-based implants. The immersion tests indicate that these compounds were degraded according to the atomic ratio of the elements in each compound. Besides that, the compounds can efficiently induce Ca-P deposition in SBF. Cytotoxicity tests demonstrate that the 10% extracts prepared from these compounds exhibit good cell activity on MC3T3-E1 cells.

Mg-Zn-Ca bulk metallic glasses (BMGs) have attracted significant attention in the field of biodegradable metallic biomaterials due to their desirable in vivo degradability and high strength. However, their relatively high brittleness limits further practical applications. In this work, porous Fe skeleton-reinforced Mg-Zn-Ca bulk metallic glass composites (BMGCs) were fabricated by pressure infiltration using porous Fe skeleton as the toughening phase and Mg66Zn30Ca3Sr1 alloy as the matrix. It was found that electroless copper plating improved the interfacial wettability between molten Mg and Fe, as well as the infiltration-forming capability of the BMGCs. Quasi-static compression tests showed that the BMGC exhibited a compressive strength of 500 MPa, a plastic strain of 0.2%, and a yield strength of 420 MPa, representing a significant improvement over the matrix BMG alloy. The fracture surface displayed a vein-like pattern, indicating a noticeable transition from brittle to ductile fracture behavior. Thus, the porous Fe skeleton-reinforced Mg-Zn-Ca BMGC shows promise as a potential biodegradable biomedical material. Moreover, the preparation route presented here offers a new perspective for developing degradable Mg-Zn-Ca-based BMGCs.

In Antarctica, low temperatures favor the trapping and deposition of polycyclic aromatic hydrocarbons (PAHs), whereas the biogeochemical cycling of PAHs on the Southern Ocean adjacent to Antarctica is highly sensitive to climate change. However, very little environmental and ecological information is available on interannual PAHs variations in the surface of the Southern Ocean. From 2022 to 2024, we employed the 38 th , 39 th , and 40 th Chinese National Antarctic Research Expeditions (CHINARE) to collect surface water samples and conduct analyses of the spatio-temporal distribution patterns, source apportionment, and probabilistic ecological risk assessment of the 16 USEPA priority PAHs. We found that ∑PAH concentration in the study area ranged from 427 to 5782 pg/L, with median values of 1795, 1736, and 2559 pg/L for the 38 th , 39 th , and 40 th expeditions, respectively, showing a latitudinal gradient pattern of higher concentrations at lower latitudes and lower concentrations at higher latitudes. A significant concentration rebound was observed in the 40th expedition. Integrated analysis using molecular diagnostic ratios, PCA, and PMF revealed that this rebound was driven by a distinct “dual-pressure pattern”: intensified logistical traffic emissions (combustion sources) and the persistent release of fresh, unweathered PAHs. Source apportionment indicated an evolutionary trend from mixed petrogenic and ship-related liquid fuel combustion (38th) to episodic fresh local inputs (39th), culminating in the complex superposition of sources in the 40th survey. Probabilistic risk assessment using Monte Carlo simulations confirmed that acute risks to plankton remain low (the 95th percentile of ∑RQ MPC was 0.077); However, a structural shift towards hydrophobic high-molecular-weight PAHs (increasing to ~18% in 2024) signals a rising hidden potential for biomagnification in keystone species like Euphausia superba . These findings provide a critical scientific baseline for identifying pollution sources and supporting Antarctic ecosystem management under changing environmental conditions.