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High-yield growth of large-sized single-crystal hexagonal boron nitride (hBN) bulk is receiving growing research interest due to its graphene-like two-dimensional structure while having distinct electrical and optical properties. In this study, enhanced yield and domain size were realized by adding carbon into the metal flux system (Ni–Cr) under atmospheric pressure. We found that both the yield and domain size increased more than 10 times in optimized carbon amount when compared with metal flux without carbon added. X-ray diffraction, Raman scattering, transmission electron microscope, energy-dispersive X-ray spectroscopy, and electron energy loss spectroscopy results confirmed single-phase hBN without detectable carbon or metal impurity. We suggest that the use of carbon provides a low-cost, stable, and safe alternative to achieve large-sized hBN single crystals.

We reported on the direct observation of oriented attachment (OA) type edge-attachment processes during single-layer graphene flake (GF) merging using a Cs-corrected transmission electron microscope. Such a process was accompanied by e-beam induced graphene edge re-connection and was realized to be energetically favored. Details of the seamless OA processes including the in-plane rotation and alignment of GFs as well as the local structure reconstruction were revealed. It is suggested that such a mechanism may work in a self-initiated mode and induce the continuous in-plane graphene growth.

A seamless thin-walled hollow metallic cylinder with array of micro-perforations is one of the key components for some products. Normally, these micro-perforations are formed by removing material from the given metallic hollow cylinder (pipe or tube) one by one or row by row. To efficiently and flexibly manufacture such a highly perforated hollow cylinder, this paper proposed a hybrid technique combining extrusion moulding process and electroforming process. In the hybrid technique, the extrusion moulding process was used to create polymer extrusion patterns on the outside surface of the given stainless steel (SS) pipe, and then the electroforming process was carried out using the SS pipe as the mandrel. The formation of the polymer extrusion patterns was simulated and extruding molding experiments were carried out to examine the feasibility of the various mandrels. Electroforming experiments were implemented to verify the achievement of the seamless perforated thin-walled hollow cylinder. It was found that five different types of polymer extrusion pattern were able to be obtained on the same extruding pipe just by adjusting some extruding conditions and parameters, and correspondingly four types of perforated hollow cylinder with different tapered orifices are produced after the electroforming process. The obtainable perforations are: perforation with double conic-orifices, perforation with hemispheric orifice and conic orifice, unidirectionally tapered perforation, and straight-walled perforation. The geometric profile of the extrusion patterns is highly dependent on the processing conditions and parameters. The proposed hybrid process represents a promising alternative process to fabricate seamless thin-walled perforated hollow metallic cylinder efficiently, flexibly, and with low cost.

The application of bioscouring in cotton knitted fabrics should be improved owing to being a time-consuming process. In order to accelerate the bioscouring rate and shorten the bioscouring process, a repeated padding method is used on cotton knitted fabrics. The effect of the repeated padding with pectinase was studied by using FE-SEM and FTIR, and the catalytic rate was measured at different reaction temperatures, pick-up, and soaking times. The results observed in this study showed that during the bioscouring process for cotton knitted fabrics, the average catalytic rate of the repeatedly padding method was sixfold faster than the impregnation method, and the process time (15 min) decreased by 65 minutes compared with the impregnation method (80 min); the processing time was shortened to one-sixth of the impregnation method. Furthermore, the wettability of cotton knitted fabrics was better than those treated via impregnation. In the repeated padding process, with the soaking time increasing from 5 s to 25 s, the produced reducing sugar concentration increased from 1.71 mg/ml to 3.60 mg/ml in the same process time; with the pick-up increased from 50% to 90%, the produced reducing sugar concentration first increased from 1.99 mg/ml to 3.60 mg/ml, then decreased to 1.86 mg/ml. When the pick-up was about 70%, the catalytic rate of pectinase reached the best value (0.24 mg/ml/min).

We observed a super-wetting behavior at typical chemical vapor deposition grown transition metal di-chalcogenide (TMDC) 2D material–substrate interface. Such an interface was found to keep a flat, nanoscale water film when interacting with liquid state water. Detailed in situ atomic force microscope studies found the variable thickness of the water layer. Both surfaces at the two sides of the interface, viz. the TMDC (MoS2 or WS2 as demonstrated) bottom surface and the exposed substrate (typically, the as-grown SiO2) surface, were found to be super-wetting. This insured effectively their stable super-wetting behaviors. We further verified a prompt relationship of the nanoscale water layer with the water-mediated transfer of the TMDC. The super-wetting layer was found essential and critical for the effective transfer of TMDCs to other surfaces.

An experimental study on economical and emission characteristics of a high-speed inter-cool diesel engine with butanol-diesel blended fuel was executed. With the butanol blended by three volume ratios (0%, 20% and 30%) in the diesel, the brake special fuel consumption (BSFC) and soot emission were analyzed under different loads. The results show that the fuel with 30% butanol has little influence on the maximal brake power and maximal brake torque while the BSFC just increases 1.6% at the maximal brake torque condition and 2.6% at the maximal brake power condition. The ratio of butanol has little effect on soot emission in the medium speed (2000r/min), while in the high speed condition (4000r/min), it decreases noticeably with the increase of the amount of butanol. The soot emission was reduced by 35.8% for the fuel with 20% butanol at the maximal torque point and 39.9% down for the 30% butanol fuel. These results can be helpful for the future research where large volume ratio of butanol is used for a diesel engine.