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In this work, Huadian oil shale was extracted by subcritical water at 300 °C over different time periods to better characterize the underground mining of oil shale in situ. The results revealed that the kerogen in the oil shale mostly transformed into bitumen through extraction over a long time period by subcritical water at 300 °C; however, a portion of the bitumen remained in the shale matrix. The yields of both bitumen 1 (the bitumen extracted by subcritical water) and bitumen 2 (the bitumen remaining in the shale matrix) reached maximums at approximately 250 h. It should take a long time for bitumen 2 to be released because the ability of the transporting substrates of subcritical water was insufficient, the solubility of bitumen 2 was poor, and tiny fractures were generated in the oil shale matrix at such a low temperature. The gas chromatography–mass spectrometry analysis showed that the major components of bitumen 1 and bitumen 2 were similar and consisted of n-alkanes, n-alkanoic acids, n-alk-2-ones, and isoprenoid alkane. Initially, kerogen decomposition produced a large number of n-alkanes with low molecular weights; however, as the reaction continued, comparatively higher-molecular-weight n-alkanes were obtained more. In addition, the bitumen underwent a secondary cracking in the subcritical water, resulting in its decreased yield over time, whereas the contents of gaseous C2–C6 hydrocarbons increased. The organic matter dissolved in the spent aqueous solution consisted of mainly paraffins, isoparaffins, cyclohexanone derivatives, and phenolic derivatives. The analysis of the oil shale residue showed that minerals were less reactive in the subcritical water except for feldspar and calcite and that mesopores developed in the oil shale with prolongated extraction time, as more bitumen diffused out and into the subcritical water at 300 °C.

A series of phenanthroline-based ligands have been synthesised and their influence as bidentate nitrogen ligands in heteroleptic [Cu(P^P)(N^N)] photosensitisers in light-driven water reduction has been studied. In this noble-metal-free Cu-Fe-based photocatalytic water reduction system, the structural effects of the nitrogen ligands have been explored, including the steric and electronic effects of substituents at the 2,9- and 4,7-positions of phenanthroline. Ligands were prepared that led to increased hydrogen generation, with turnover numbers (TON ) of up to 1388 being observed. All the new complexes were electrochemically and photophysically characterised. We demonstrate for the first time that the presence of fluorine in nitrogen ligands increases the efficacy of copper complexes in photocatalytic hydrogen production.

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A rapid and sensitive chemiluminescence (CL) method using flow injection analysis is described for the determination of four catecholamines, dopamine, adrenaline, isoprenaline and noradrenaline, based on their greatly enhancing effects on the CL reaction of luminol-potassium periodate in basic solutions. The optimized chemical conditions for the chemiluminescence reaction were 1.0 x 10(-4) mol/L luminol and 1.0 x 10(-5) mol/L potassium periodate in 0.2 mol/L sodium hydroxide (NaOH). Under the optimized conditions, the calibration graphs relating the CL signal intensity (peak height) to the concentration of the analytes were curvilinear and they were suitable for determining dopamine, adrenaline, isoprenaline, and noradrenaline in the range 0.1-10 ng/mL, 0.1-100 ng/mL, 1-100 ng/mL and 5-50 ng/mL, respectively, with the relative standard deviations of 0.8-1.7%. The detection limits of the method are 0.02 ng/mL for dopamine, 0.01 ng/mL for adrenaline, 0.1 ng/mL for isoprenaline and 2.0 ng/mL for noradrenaline. The sampling frequency was calculated to be about 60/h. The selectivity of the method was good, because a series of common ions or excipients, such as K(+), Ba(2+), CO(3)(2-), NO(3)(-), SO(4)(2-), PO(4)(3-), sodium citrate, sodium bisulphite, oxidate dopamine, starch, lactose, carbamide and gelatin, could not produce interference when their concentrations were 1000-fold than those of dopamine. The present method was successfully applied to the determination of the four catecholamines in pharmaceutical injections.

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A boron carbide coating was applied to diamond particles by heating the particles in a powder mixture consisting of H3BO3, B and Mg. The composition, bond state and coverage fraction of the boron carbide coating on the diamond particles were investigated. The boron carbide coating prefers to grow on the diamond (100) surface than on the diamond (111) surface. A stoichiometric B4C coating completely covered the diamond particle after maintaining the raw mixture at 1200 °C for 2 h. The contribution of the boron carbide coating to the oxidation resistance enhancement of the diamond particles was investigated. During annealing of the coated diamond in air, the priory formed B2O3, which exhibits a self-healing property, as an oxygen barrier layer, which protected the diamond from oxidation. The formation temperature of B2O3 is dependent on the amorphous boron carbide content. The coating on the diamond provided effective protection of the diamond against oxidation by heating in air at 1000 °C for 1 h. Furthermore, the presence of the boron carbide coating also contributed to the maintenance of the static compressive strength during the annealing of diamond in air.