Scientific investigations on the non-chemical modification of lignocellulosic fibers are important for engineers when they design green wood-plastic composites. Two types of lignocellulosic fibers, namely rice husk and rice straw fibers, were studied. The physicochemical and thermal properties of the fibers with and without seawater modification were compared. The results suggested that seawater modification improved the physicochemical and thermal properties of the fibers, and that it specifically increased the surface roughness, crystallinity, and pyrolysis temperature at 5% weight loss, and decreased the silicon, hemicellulose, and lignin content of the fibers. Compared with rice husk fibers, rice straw fibers exhibited a high growth ratio of crystallinity and pyrolysis temperature at 5% weight loss, and a high loss ratio of silicon. Seawater modification of rice husk and rice straw fibers could improve fiber–polymer compatibility.

The use of radial jet drilling (RJD) to exploit unconventional natural gas is an attractive study area. A self‐propelled bit enormously affects the drilling efficiency. Herein, for a straight‐swirling mixed jet (SSMJ) bit, the internal and external velocity fields were analyzed using a simulation to reveal a jet mixed mechanism. The rock‐breaking characteristics of different bit structures were investigated using laboratory experiments. A straight jet and a swirling jet were independent flowing through the impeller and were gradually mixed together in the mixing chamber inside the bit. The jets' boundary gradually dissipated along the radial direction, and the swirling jet distribution along the circumferential direction tended to be uniform. The velocity vector gradually decreased from the center to the periphery, and the energies were slowly concentrated due to the cluster‐narrowing by the conical wall until the velocity at the nozzle outlet reached its peak. Different flow fields were modulated by changing the bit structures. The diameters ratio greatly affected the distribution proportion of straight and swirling; the length‐diameter ratio primarily affected the contribution of the swirling jet to its center, and the width‐diameter ratio chiefly affected the initial formation velocity of the swirling jet, which all directly affected the depth variation along the radial and diameter of a borehole. The hole depth and diameter, erosion volume, and bottom flatness were combined to evaluate the rock‐breaking performance. The bit with a diameters ratio of 0.67, a length‐radius ratio of 0.57, and the width‐radius ratio of 0.13 had the best erosion effect. The simulation and experimental results achieved good mutual verifications. Overall, this study can guide research on the SSMJ rock‐breaking mechanism and bit design for RJD.

Lignocellulosic fibers have been widely used to reinforce polymer composites. Chemical modification of the fibers can improve the fiber properties and fiber-polymer interfacial compatibility. This study considered an eco-friendly process that can reduce environmental pollution by modifying lignocellulosic fibers using seawater rather than chemical reagents. The effects of seawater modification on the physical, chemical, and thermal properties of lignocellulosic fibers obtained from wheat straw were investigated. After seawater modification, the modified fibers had a lower number of hydrogen bonds, hemicellulose, lignin, and silicon content, and higher water absorption, crystallinity, surface roughness, and thermal stability. Considering the essential components of seawater, the contribution of NaCl during the modification process was the most significant, followed by that of the bivalent salts (MgCl₂ + CaCl₂ + SrCl₂), Na₂SO₄, and trace-component (KCl + NaHCO₃ + KBr + H₃BO₃ + NaF).

An 6201Al alloy was rolled at room temperature (RT), liquid nitrogen and alcohol mixed temperature (LAT) and liquid nitrogen temperature (LNT). The effect of the rolling temperature on microstructure and mechanical properties was investigated by means of hardness measurements, tensile tests, optical microscopy (OM), transmission electron microscopy (TEM) and scanning electron microscopy (SEM). Microstructural observations reveal that the dislocation tangles and dislocation density increased with decreasing rolling temperature. The dislocation accumulation was enhanced, and the formation of dislocation tangles and cells occurred during deformation under low rolling temperature. The substructures of the rolled sample at LAT and LNT are similar, consisting of dislocation cells, high dislocation density with networks, dislocation array, dislocation tangles and subgrains. Compared with rolled samples at RT and LAT, the rolled samples at LNT presented strengthened hardness and strength. The improvement of mechanical properties contributes to the fine substructures and accumulation of higher dislocation density during low temperature rolling. In addition, with decreasing rolling temperature, the average dimple size decreased.