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Microalloying and heat treatment are essential processing techniques for ferritic stainless steel (FSS). Three different compositions of 21%Cr FSS with 0.28Ti, 0.21Ti + 0.05Nb, and 1.05Ti + 0.17Nb were prepared. The interaction effects of the Nb and Ti contents and hot-rolling annealing on the microstructure, mechanical properties, and precipitate phases of FSS were studied. The microstructure, crystal structure, and precipitation phase of steel at 930, 980, and 1030 °C with Ti-Nb microalloying were investigated using an optical microscope (OM), X-ray diffractometer (XRD), and scanning electron microscope (SEM). The room-temperature tensile properties, surface roughness, and hardness were tested separately. This study found that the composite addition of Ti and Nb had a dual effect of fine-grain strengthening and precipitation strengthening. The 1.05Ti + 0.17Nb steel specimen had a moderate grain size and the best uniformity after hot rolling at 980 °C. The tensile strength and elongation were 454 MPa and 34.2%, which achieved an optimal balance between strength and plasticity. [ABSTRACT FROM AUTHOR]

Crystal growth regulation has become an effective solution to reduce the defects at grain boundaries (GBs) and surfaces of perovskite films for better photovoltaic performances. Oxime acid materials are maturely used as selective collectors in the flotation separation of oxide minerals. Such materials, showing a strong coordination effect and high selectivity with lead, may have great potential in controlling the crystal growth and passivating the defect of perovskite film, which are rarely applied in perovskite solar cells (PerSCs). Herein, an oxime acid‐based material with multi‐coordination sites, ethyl 2‐(2‐aminothiazole‐4‐yl)‐2‐hydroxyiminoacetate (EHA), is incorporated into the PbI2 precursor solution to fabricate high‐performance PerSCs using a two‐step method. The multidentate coordination effect of EHA can link and integrate the PbI2 colloidal clusters to achieve pre‐aggregation in the PbI2 precursor solution, facilitating the sequent crystal growth progress of perovskite film. Meanwhile, EHA can connect grains and fill GBs, which is favorable for charge transfer and passivating both Pb‐I anti‐site and iodine vacancy defects. As a result, the optimal devices show an enhanced efficiency of 24.1% and excellent humidity and thermal stability. This work affords a promising strategy to fabricate efficient and stable PerSCs via multidentate coordination‐induced crystallization control and GB passivation. [ABSTRACT FROM AUTHOR]

Tin oxide (SnO2) is broadly used as an electron transport layer (ETL) in organic solar cells (OSCs). However, there are many hydroxyl groups and the defects of oxygen vacancy on the surface of SnO2, resulting in charge recombination. Herein, an electrolyte 4‐(dimethyl(pyridin‐2‐yl) ammonio)butane‐1‐sulfonate (PAS) is doped into SnO2 films with an appropriate proportion to improve the performance of the inverted OSCs. The PAS can coordinate with the Sn atoms in SnO2 films to reduce the surface defects, resulting adjustable work function and increased electron conductivity. Meanwhile, the PAS doping can decrease the surface energy of SnO2 layer, forming vertical phase distribution of the active layer for better exciton dissociation and charge transport. The PM6:Y6 based inverted OSC with SnO2 ETL shows a power conversion efficiency (PCE) of 14.72%, while the device with PAS‐doped SnO2 ETL demonstrates greatly enhanced PCE of 16.37%. The device performance can be further improved by using PM6:BTP‐eC9 as active layer and a PCE of 17.12% can be achieved with PAS‐doped SnO2 ETL. Furthermore, PAS‐doped SnO2 can effectively enhance the device stability under continuous illumination. These findings demonstrate that exquisite regulation of SnO2 layer via a small electrolyte molecule coordination is a promising approach to achieve efficient and stable inverted OSCs. [ABSTRACT FROM AUTHOR]

The ecological and environmental relationship between a natural reserve (NR) and its surrounding area is a ‘hotspot’ in the human–environment relationship. However, the effect of landscape pattern of the surrounding land-use changes on the NR has not been thoroughly explored. How to protect the NR has become an issue of major concern. This research analysed the land-use/land-cover (LULC) change of the NR and its surrounding area using Landsat Thematic Mapper (TM) images and applied theories of landscape ecology to study the effect of the surrounding LULC on the wetland landscape of the NR in Tianjin, China. The results show that (1) the wetland area decreased from 122,461.11 ha in 1988 to 111,753.99 ha in 2008 while the built-up area expanded from 11,983.22 ha in 1988 to 20,197.71 ha in 2008; (2) landscape diversity will increase along with direct LULC in the NR and its surrounding area, where human activities have already diversified the original wetland landscape; and (3) the unitary landscape has been replaced by diverse landscapes and the land type that was once dominant has lost its status. Restoring the watershed wetland is a good method for realising protection of the NR. [ABSTRACT FROM PUBLISHER]

Bright‐band defects frequently occur on as‐cast strips in the twin‐roll strip‐casting process, particularly at low‐casting speeds, with intervals of ≈200 mm. Additionally, the cast‐rolling force also exhibits minor fluctuations. With increasing casting speeds, the spacing between bright‐band defects widens, and the severity of these defects diminishes. When the casting speed reaches a certain threshold, defects almost entirely disappear. Detailed analysis of the underlying causes of this phenomenon is essential for effectively preventing defect formation. In this study, the numerical simulation method is employed to analyze casting rolls’ thermal deformation and the melt pool's solidification behavior, based on the production site equipment and process conditions. The causes of defects in as‐cast strips are thoroughly analyzed based on simulation results, in conjunction with variations in the cast‐rolling force. In this study, it is demonstrated that the thermal deformation of casting rolls and the position of the solidification endpoints collectively contribute to the fluctuations in cast‐rolling force and are the primary causes of bright‐band defects. Fundamental principles for preventing defects are provided based on actual on‐site production. Furthermore, simulation results contribute to establishing a theoretical basis for selecting process parameters and controlling cast‐rolling force during production. [ABSTRACT FROM AUTHOR]