Effect of moisture on mechanical and physical properties of coals: a uniaxial compression study.

The estimation of mechanical and physical properties of coal reservoirs is important for the successful exploration and development of coalbed methane (CBM). Unlike conventional sandstone reservoirs, coal reservoirs exhibit greater sensitivity to stress, resulting in distinct mechanical and physical behaviors. In this study, uniaxial compression tests were performed on both low-rank and high-rank coal samples under different moisture conditions to reveal the mechanical and physical property changes with stress.

Design of Ca-type todorokite catalysts with highly active for the selective reduction of NO by NH at low temperatures.

Ca-type todorokite catalysts were designed and prepared by a simple redox method and applied to the selective reduction of NO by NH (NH-SCR) for the first time. Compared with the Na-type manjiroite prepared by the same method, the todorokite catalysts with different Mn/Ca ratios showed greatly improved catalytic activity for NO reduction. Among them, Mn8Ca4 catalyst exhibited the best NH-SCR performance, achieving 90% NO conversion within temperature range of 70-275°C and having a high sulphur resistance.

Gastroprotective 2-(2-phenylethyl)chromone-sesquiterpene hybrids from the resinous wood of Aquilaria sinensis (Lour.) Gilg.

Six previously unprecedented 2-(2-phenylethyl)chromone-sesquiterpene hybrids, aquisinenins A-F (1 - 6), were isolated from the resinous wood of Aquilaria sinensis by a LC-MS-guided fractionation procedure. Their structures were determined by extensive spectroscopic analysis (1D and 2D NMR, UV, IR, and HRMS) and experimental and computed ECD data. Compounds 1 - 6 were rare dimeric 2-(2-phenylethyl)chromone-sesquiterpene derivatives featuring 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone hybridized with different sesquiterpene (eudesmane/guaiane type) moieties via ester bond.

Phenolic Glucosides from the Leaves of Vitex negundo var. cannabifolia.

Four new phenolic glucosides, cannabifolins G-J (1-4), together with four known ones (5-8), were isolated from the leaves of Vitex negundo var. cannabifolia. Their structures were established by comprehensive analysis of 1D and 2D NMR data and comparison of their spectroscopic and physical data with the literature values.