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Application‐oriented assembly of two‐dimensional nanosheets with uniform nanochannels is critical for fabricating sophisticated, high‐performance membranes for water treatment. However, fabricating the desired membranes by a simple, fast, and effective method is a challenge as most of the previous methods are based on batch processes rather than a continuous roll‐to‐roll process. Here, a simple Meyer rod‐coating approach to continuously fabricate large‐size and flat MXene membranes at a scale up to 5 m is introduced. This study demonstrated that a high MXene concentration, above 10 mg mL−1, is critical in processability due to the desired viscosity, surface tension, and viscoelastic properties. The as‐made MXene membranes show that shearing and solutal‐Marangoni flow can considerably improve the ordering of the stacked MXene nanoflakes. Thus, the rod‐coated MXene membranes demonstrate a smaller surface roughness and interlayer distance compared to the MXene membranes fabricated by the most commonly vacuum‐assisted filtration. The rod‐costed MXene membranes show superior performance in dye and mono/divalent cation separation. The proposed roll‐to‐roll Meyer rod‐coating method can also be used to fabricate MXene‐based composites, such as MXene/carbon nanotubes and MXene/polymer, using the inks containing high concentration MXene and other desired compositions. This roll‐to‐roll method will promote an industry‐level fabrication and application of MXene‐based membranes. [ABSTRACT FROM AUTHOR]

Zearalenone (ZEN) is one of the most common mycotoxin contaminants worldwide. In this study, a phage‐based direct competitive fluorescence immunosorbent assay (P‐dcFLISA) was developed for the detection of ZEN. In this P‐dcFLISA, phage mimotope was used to replace chemically synthesized antigens to improve the safety of experiments. Furthermore, ZnCdSe/ZnS (core/shell) quantum dots (QDs) as fluorescent labeling material replaced chromogenic substrate, which are used in traditional ELISA. The 50% inhibition value (IC50) of P‐dcFLISA was 0.301 ng/ml, which was approximately 12‐fold lower than that of phage‐based indirect competitive enzyme‐linked immunosorbent assay (P‐icELISA). The limit of detection (LOD) of P‐dcFLISA was 0.023 ng/ml and the detection range was 0.060–1.531 ng/ml. In the added recovery assay, recovery rate was 93.18–105.52%, with the coefficient variation (CV) ranging from 8.39% to 10.55%. The establishment of P‐icFLISA not only save time, but also avoid the use of mycotoxins in the detection process, providing a safe method for the detection of mycotoxins. In conclusion, phage‐based fluorescence immunoassay method has great potential application in ZEN detection and agricultural monitoring. [ABSTRACT FROM AUTHOR]

Ultrathin, transparent, and free‐standing films assembled from low‐dimensional nanomaterials (LDMs) are promising for various applications, including transparent heaters and membranes. However, the intact separation of the assembled films, especially those with controlled ultrathin thickness from deposited substrates, is a tremendous challenge, particularly for fast peeling off via self‐detaching. Herein, we propose a versatile method to rapidly peel off ultrathin assembled LDM films, including three types of carbon nanotubes, vermiculite, Ag nanowires, and carbon nanotube@graphene, by dissolving the MXene interlayer from the layer‐by‐layer filtered MXene/LDM Janus films using diluted H2O2. The MXene sacrificial interlayers play dual roles, including physical isolation of LDM films from filter membranes and the production of bubbles that buoy ultrathin LDM films, making them free‐standing. The integrality and self‐detaching rate of the LDM films are determined by the loading and reactivity of the MXene interlayers. The intact LDM films can self‐detach in 80 s by dissolving the optimized MXene interlayer and producing bubbles. The as‐made free‐standing ultrathin LDM films can be transferred to arbitrary substrates and exhibit outstanding performance as transparent heaters. This scalable method provides an efficient and versatile method to produce ultrathin, transparent, and free‐standing LDM films and finds new applications for the growing MXene family. [ABSTRACT FROM AUTHOR]

Computational spectroscopic instruments with broadband encoding stochastic (BEST) filters allow the reconstruction of the spectrum at high precision with only a few filters. However, conventional design manners of BEST filters are often heuristic and may fail to fully explore the encoding potential of BEST filters. The parameter constrained spectral encoder and decoder (PCSED)—a neural network‐based framework—is presented for the design of BEST filters in spectroscopic instruments. By incorporating the target spectral response definition and the optical design procedures comprehensively, PCSED links the mathematical optimum and practical limits confined by available fabrication techniques. Benefiting from this, a BEST‐filter‐based spectral camera presents a higher reconstruction accuracy with up to 30 times enhancement and a better tolerance to fabrication errors. The generalizability of PCSED is validated in designing metasurface‐ and interference‐thin‐film‐based BEST filters. [ABSTRACT FROM AUTHOR]

Natural gas hydrate is considered to be a promising future energy resource; therefore, obtaining its physical properties is crucial for evaluating gas production efficiency and developing reasonable exploitation strategies. In this study, we present a novel pore‐scale 3D morphological modeling algorithm considering various saturation and occurrences (cementing and pore‐filling) of hydrate in sediments. To evaluate the performance of the presented algorithm, 14 hydrate‐bearing sediment models were constructed based on X‐ray computed tomographic images of a consolidated sandy specimen under an effective stress of 3 MPa. Morphologically, the new algorithm generated pore‐scale hydrate occurrences coincide with published morphological behaviors of hydrate observed via computed tomography. The tortuosity and fractal dimension of pore spaces of these models were then characterized. The pore networks are also extracted, based on which the evolution of the pore characteristics including the distributions of pore radius, throat radius, throat length, and the coordination number were investigated. Using these generated models, simulations of permeability, thermal conductivity, and electrical conductivity were conducted to evaluate the influences of hydrate saturation and occurrence. These results are validated against published data, demonstrating that this algorithm could be an effective way to construct digital hydrate‐bearing sediment models using a single set of computed tomographic images of a hydrate‐free specimen. This new method can also be significant for the physical evaluation of natural cores in which hydrate has dissociated during core recovering and transferring. Key Points: A novel algorithm for generating digital hydrate‐bearing models with different saturations and occurrences was presentedThe pore space systems of the hydrate‐bearing models with different saturations and occurrences were characterizedSimulations of permeability, thermal and electrical conductivities considering hydrate saturations and occurrences were conducted [ABSTRACT FROM AUTHOR]

In this study, a microfocus X‐ray computed tomography‐based triaxial testing apparatus was used to observe and quantify the microstructure evolution of hydrate‐bearing sands during thermal dissociation of hydrate. Three triaxial shear tests with X‐ray computed tomography were conducted to study the influence of hydrate dissociation on the mechanical behavior of hydrate‐bearing sands. The results show that hydrate covering the sand particle surface dissociates first and then at the menisci between sand particles. The secondary hydrate formation mainly occurs on the menisci between sand particles and the surfaces of the hydrate shells where hydrates already exist. Hydrate dissociation could cause fabric changes in hydrate‐bearing sands, resulting in a more isotropic orientation distribution of sand particles. The failure behavior of the hydrate‐free sand specimen is similar to that of the specimen after hydrate dissociation, which shows an obvious drum‐shaped failure pattern with X‐shaped shear bands. However, the hydrate‐bearing sand specimen exhibits a shear band with a determined thickness and inclination angle. Hydrate dissociation could cause a significant loss of supporting cementation, resulting in a decline in the stiffness and failure strength. The failure strength of hydrate‐free sand specimen is slightly higher than that of the specimen after hydrate dissociation; this may due to that the homogeneous orientation frequency distribution can enhance the stability of the force chain between sand particles. The secondary hydrate formation causes sediment deformation resulting in a decrease in absolute permeability due to pore blockage. Key Points: Hydrate dissociation causes deformation and fabric changes in hydrate‐bearing sandsThe failure behavior of hydrate‐free sands is similar to that of hydrate‐bearing sands after dissociationSecondary hydrate formation during dissociation would influence the permeability significantly [ABSTRACT FROM AUTHOR]

A phase-pure and high-brightness blue phosphor, Eu2+ doped SrMgAl10O17 ( SAM), was synthesized through a hybrid urea-sol combustion route. The structure, photoluminescence spectra, and thermal stability of the SAM were investigated in this work. The phosphor had a homogeneous and rod-like microstructure, showing a broad emission band centered at 465 nm under the 330 nm excitation. The concentration for luminescence quenching of SAM: Eu2+ occurred at 10 mol%, which doubled that of the phosphor prepared by the conventional combustion method. Compared with the traditional combustion method, the hybrid route led to improvements in luminescence by 52.2%, external quantum efficiency by 16.2%, and thermal stability by 8.8% at 435 K. The blue phosphor prepared by the new method could thus be potentially used with near ultraviolet light-emitting diodes. [ABSTRACT FROM AUTHOR]

The macromechanical properties (strength, stiffness, stress‐strain relationship, etc) of the hydrate‐bearing sediment are often correlated with the hydrate cementation failure behavior. In this study, a consolidated drained triaxial shear test with X‐ray computed tomography was conducted on a hydrate‐bearing sediment with a hydrate saturation of 32.1% under 3 MPa effective confining pressure for revealing the cementation failure behavior. The hydrate occurrences were clearly identified to be cementing, grain‐coating, prepatchy cluster and patchy cluster. The cementation failure behavior (morphology), deformation evolution (quantitative statistics), and localized shear deformation at different regions of stress‐strain curve were observed and analyzed using computed tomography. In the linearity region, the hydrate‐cemented clusters moved as a whole, while small hydrate particles would aggregate to the periphery of the clusters. The noncemented sand particles move disorderly during this process. Localized deformation occurred perfectly exhibit an antisymmetric bifurcation pattern. In the plasticity region, the specimen starts to deform plastically; an internal shear band occurs in the specimen. The hydrates begin to shed from the periphery of the cemented structure, and the grinding effect of hydrates begins to occur between sand particles. However, the shedded hydrates will not enter and fill the neighboring pores but hind the movement of sand particles structurally near the original position. In the yielding region, the hydrate‐cemented cluster structure is completely damaged and crushed into small pieces; a shear band with a determined thickness and inclination angle was observed. Key Points: The cementation failure behavior of hydrate‐bearing sediment corresponding to different regions of stress‐strain curve is observed by CTThe localized deformation development at different regions of stress‐strain curve was determined and analyzedThe quantitative statistics of hydrate cementation failure behavior was analyzed [ABSTRACT FROM AUTHOR]