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For the increasing well plugging in oilfield development, a new unplugging technology is presented in this paper for the downhole plugging by using high voltage pulse wave. Based on the mechanism analysis, the circuit resistance model and the empirical calculation formula of the pressure shock wave are obtained, and the influence of the same current waveform on the pressure shock wave generated by the wire explosion is preliminarily studied in laboratory experiments under different energy conditions. A corresponding unplugging evaluation test device was designed to simulate the approximate downhole reservoir conditions in the places where the shock wave occurs to test the approximate downhole stress conditions of the core, and to test the permeability changes after different shock waves acted on the core. The results show that the peak value of the pressure shock wave is proportional to the effect of well unplugging, which verifies the feasibility of the unplugging and increasing permeability technology of the electric explosion-controlled shock wave. This technology can quickly dredge the oil seepage channel, increase well permeability, thus increasing the well productivity, which has a broad application prospect and important practical significance.

The hydrothermal liquefaction (HTL) of As enriched Pteris vittata L. (PVL, hyper-accumulator biomass) was performed with the recycled aqueous phase as reaction medium, aiming to dispose the biomass with high water content and produce high-quality bio-oil. After three times of aqueous phase recycling at 275 °C, 30 min, the bio-oil yield increased to 30.32% from 21.54% and the higher heating value (HHV, 28.51 MJ/kg) of the bio-oil was higher than that of the bio-oil from HTL with pure water (26.80 MJ/kg). The main compounds detected in bio-oils were phenols, ketones, hydrocarbons, and aldehydes. Acetic acid (17.21–24.77 mg/mL) was dominant in the aqueous phases, resulting in the low pH (4.31–4.89). The heavy metals (Cu, Pb, Zn, Cd) mainly remained in bio-char whereas As was transferred to aqueous phase. Thus, HTL by aqueous phase recycling could be a promising way for PVL treatment to obtain high-quality bio-oil and arsenic recovery.

Cesium tungsten bronze (Cs0.33WO3) coatings can effectively depress solar heat gain and air-conditioning energy consumption of buildings, because of their highly selective near infrared (NIR) absorbing ability. However, the absorbed solar energy may overheat the window glasses due to the high photothermal conversion efficiency of Cs0.33WO3 coatings, discounting their transparent heat insulating performance. To solve this issue, we design a new energy-efficient composite window by integrating NIR-shielding Cs0.33WO3 with phase change materials (PCMs, paraffin wax in our case). In the composite window, the hexagonal-phase Cs0.33WO3 is prepared by a solid-state reaction method, and then coated onto commercial float glass as Cs0.33WO3–SiO2 composite films via a sol–gel process. Afterwards, a homemade double-plane window consisting of a float glass and a Cs0.33WO3–SiO2-coated glass is filled by molten commercial paraffin wax to obtain the paraffin wax–Cs0.33WO3 composite window. Cs0.33WO3 in the window can reduce solar heat gain of the buildings. Meanwhile, the paraffin wax component can accumulate the Cs0.33WO3-captured thermal energy by its endothermic molting processes, protecting the window from overheating. When the ambient temperature drops low enough, the stored thermal energy in the paraffin wax can be gradually released back by reverse solidifying processes. Therefore, this paraffin wax–Cs0.33WO3 composite window should be very effective to keep indoor temperature stable and comfortable. Performed on a homemade house model, the paraffin wax–Cs0.33WO3 composite window can depress indoor temperature variation from 24.2 down to 7.3 °C, compared with a bare glass window. This composite window is expected to improve energy efficiency of buildings locating in areas with high day–night or summer–winter temperature fluctuations.

The growth mechanism of GaN epitaxial layers on mechanically exfoliated graphite is explained in detail based on classic nucleation theory. The number of defects on the graphite surface can be increased via O-plasma treatment, leading to increased nucleation density on the graphite surface. The addition of elemental Al can effectively improve the nucleation rate, which can promote the formation of dense nucleation layers and the lateral growth of GaN epitaxial layers. The surface morphologies of the nucleation layers, annealed layers and epitaxial layers were characterized by field-emission scanning electron microscopy, where the evolution of the surface morphology coincided with a 3D-to-2D growth mechanism. High-resolution transmission electron microscopy was used to characterize the microstructure of GaN. Fast Fourier transform diffraction patterns showed that cubic phase (zinc-blend structure) GaN grains were obtained using conventional GaN nucleation layers, while the hexagonal phase (wurtzite structure) GaN films were formed using AlGaN nucleation layers. Our work opens new avenues for using highly oriented pyrolytic graphite as a substrate to fabricate transferable optoelectronic devices.

Both Mo and W belong to VIB-sub-group, and possess similar ionic radii, electronegativity and oxide lattice configuration. Herein, Mo-doped (0–80 at.%) tungsten bronzes, M x WO 3 , were hydrothermally prepared to systematically explore the influence of Mo-doping on their micro-structure and optical performance. The products adopted a hexagonal structure within 6 at.% Mo-doping, and transformed into a monoclinic phase with higher Mo-doping content. Further tests suggested that 1.5 at.% Mo-doping is beneficial for the formation of pure hexagonal phase and uniform nano-rod morphology. Optical measures showed that all samples exhibited high and comparable visible transmittance (70–80%), but a very different near infrared (NIR) shielding ability. The sample doped with 1.5 at.% Mo demonstrated the best NIR shielding ability with a transmittance minimum of 20% at 1300 nm. Further increase of Mo-doping dosage remarkably deteriorated NIR shielding ability by depressing the absorption of localized surface plasmon resonance (LSPR). However, the optical absorption from small-polaron was less influenced by the introduction of Mo. As a result, Mo-doping caused an evident blue shift of the infrared absorption peaks from 1350 to 750 nm.

Micro-porous activated carbons (ACs) with a narrow pore size distribution of 0.4–0.6[Formula: see text]nm and high specific surface areas (1160–1315[Formula: see text]m2[Formula: see text][Formula: see text] g[Formula: see text] are prepared from environment-friendly, low-grade potassium humate (HA-K, carbon resource) and mild activating agent potassium acetate (CH3COOK). Microstructure characterizations indicate that the introduction of activating agent CH3COOK is a key step to achieve high specific surface area and carbonization degree. These ACs contain small amount of oxygen and nitrogen, and show obvious pseudo-capacitance besides double layer capacitance. As a result, the optimized ACs achieve high specific capacitances of 311[Formula: see text]F[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] and 317[Formula: see text]F[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] at 0.1[Formula: see text]A[Formula: see text][Formula: see text][Formula: see text]g[Formula: see text] in 2[Formula: see text]M KOH and 1[Formula: see text]M H2SO4aqueous electrolytes, respectively. This sample also shows a good charge-discharge cycling stability within 10 000 cycles.