The pore characteristics and slurryability of two coal blends between Shigang anthracite coal and Huangling bituminous coal (SG/HL), and Guizhou anthracite coal and Xiaotun lean coal (GZ/XT), respectively, were investigated. The fractal dimensions of coal were calculated in the two regions of P/P-0 < 0.45 and P/P-0 > 0.45 and defined as D, and D-2, respectively. Upon an increase in the blending ratio of parent coal with smaller BET surface area (SBET) and total pore volume (TPV), the S-BET and TPV of coal blends monotonously decreased. D-1 was mainly related to the Smeso/macro(10-220 nm)/S-total and mineral phase within coal while D-2 was closely affected by the Vmeso(2-10 nm)/V-total. D-1 of SG/HL coal blends had no apparent linear correlation with the pore structure parameters whereas I), of GZ/XT coal blends changed linearly with the pore structure parameters. Both D-2 of SG/HL coal blends and that of GZ/XT coal blends changed linearly with the pore structure parameters. The slurry quality of coal water slurry (CWS) prepared from coal blends is comprehensively affected by the physicochemical properties and blending ratio of parent coals. Therefore, the maximum solid loading (MSL) and water separation ratio (WSR) of CWS prepared from coal blends do not always change linearly with the blending ratio of parent coal.
Long non-coding RNAs (lncRNAs) have been reported to play important roles in glioma; however, most of them promote glioma progression. We constructed a competing endogenous (ceRNA) network based on the Chinese Glioma Genome Atlas dataset, and lncRNA hect domain and RLD 2 pseudogene 2 (HERC2P2) is the core of this network. Highly connected genes in the ceRNA network classified the glioma patients into three clusters with significantly different survival rates. The expression of HERC2P2 is positively correlated with survival and negatively correlated with clinical grade. Cell colony formation, Transwell and cell scratch tests were performed to evaluate the role of HERC2P2 in glioblastoma growth. Furthermore, we overexpressed HERC2P2 in U87 cells and established a mouse intracranial glioma model to examine the function of HERC2P2 in vivo. In conclusion, we identified a lncRNA with tumor suppressor functions in glioma that could be a potential biomarker for glioma patients.
In order to improve the destruction efficiency of dioxins and also for developing new dioxin control technology, the destruction mechanisms of 2,3,7,8-tetrachlorodihenzo-p-dioxin (2,3,7,8-TCDD) by O(3) and NO(3), were investigated employing quantum chemical calculations. For involved reactions, the microcosmic reaction processes were analyzed and depicted in detail based on geometry optimizations made by the B3LYP/6-31G(d) method. At the same time, the reaction activation energies were also calculated at the MP2/6-311G (d,p)//B3LYP/6-31G(d) level. Configuration analysis indicated that 2,3,7,8-TCDD could be destroyed by O(3) and NO(3) in two different ways. The destruction of 2,3,7,8-TCDD by O(3) proceeded via the addition of O(3) and the cleavage of C=C while the destruction of 2,3,7,8-TCDD by NO(3) proceeded via the substitution of chlorine by NO(3). Calculated results show that, the activation energy of the destruction reaction of 2,3,7,8-TCDD by NO(3) (267.48 kJ/mol) is much larger than that of the destruction reaction of 2,3,7,8-TCDD by O(3) (51.20 kJ/mol). This indicated that the destruction of 2,3,7,8-TCDD by O(3) is much more efficient than that of 2,3,7,8-TCDD by NO(3). The reason why the activation energy for the destruction reaction of 2,3,7,8-TCDD by NO(3) is so large, is also discussed.
Ximeng lignite (XL) was treated by using different drying methods, namely, conventional, microwave, and combination, to investigate their effects on the grinding characteristics of XL. The controlled mechanisms that improved the grindability of XL treated by different drying methods were analyzed with proximate analysis and scanning electron microscope. Results showed that the removal moisture and the physical structure damage induced by thermal stress or steam jet flow improved the grindability of treated XL. Microwave drying had the most remarkable effect on the grindability of XL. The increments in grindability of XL irradiated for 0.5 and 3 min were 44.03% and 200.45%, respectively. Compared with conventional dying, combined drying simultaneously improved grindability of XL, and reduced energy consumption. However, combined drying reduced the effects of microwave drying on the increment in the grindability of XL. Drying treatment for a short period could not effectively increase the mass fraction of finely ground product unless drying time was properly prolonged. According to the economy evaluation at lab scale, treatment of XL by microwave drying for a short period improved the grindability of treated XL and achieved a maximum energy saving of around 10% after a long period of the grinding process. (C) 2015 Elsevier Ltd. All rights reserved.
The fatty acid methyl ester (FAME) compositions and combustion characteristics of the biodiesel produced from three plant oils under different supercritical methanol conditions were investigated by gas chromatography and thermobalance analyzers. When the reaction temperature increased from 255 to 300 degrees C, the conversion efficiency of rapeseed oil into FAMEs in biodiesel increased from 13% to 98%. Such increase resulted in an improved combustion property of rapeseed biodiesel with decreasing combustion activation energy from 143.6 to 84.2 kJ/mol. The ignition temperatures of the biodiesel produced from rapeseed, soybean and palm oils gradually decreased from 257.6 to 240.2 and 238.0 degrees C, which implied that the biodiesel with more C=3DC double bonds had higher ignition temperature. The ignition temperature of biodiesel was lower than that of raw plant oil, but higher than that of petroleum diesel. (C) 2014 Elsevier B.V. All rights reserved.
Coaxial elements and annular liquid jets are normally utilized in industrial applications to generate sprays. A particle image velocimetry investigation on the transient characteristics of the spray velocity field of a coaxial convergent nozzle is carried out in this paper. Based on the measurement results, spectrum analysis is performed to detect the process of atomization in the spray. Experimental results show that at large gas jet velocities, the process of generation of droplets is controlled mainly by the dynamics of liquid ligaments, and the power spectrum reveals that the velocity fluctuations are superimposed on the transient flow field by the effect of the shear layer instability. With the increase of gas velocity, the fluctuations of the spray velocity develop progressively to higher frequencies. [DOI: 10.1115/1.4006172]
The fractal characteristics of pore structures in 13 different coal specimens were investigated. Insights into the relationship among fractal dimension, pore structure parameter, and slurry ability of coal were provided. N-2 adsorption/desorption at 77 K was applied to analyze the pore structure of coal. Two fractal dimensions, D-1 and D-2, at relative pressures of 0 to 0.45 and 0.45 to 1, respectively, were calculated with the fractal Frenkel-Halsey-Hill model. Results reveal that the value of D-1 is mainly affected by the influence of meso- and macro-pores with an average pore size range of 10 nm to 220 nm on the specific surface area; therefore, Di can be utilized to quantitatively describe the surface roughness of these meso- and macro-pores in coal. Meanwhile, the value of D-2 is mainly related to the effects of fine mesopores with an average pore size range of 2 nm to 10 nm on the total pore volume; therefore, D-2 can be utilized to quantitatively describe the volumetric roughness of these mesopores in coal. Di has no apparent linear correlation with the pore structure parameters and maximum solid loading of coal, and D-2 has a positive linear correlation with the specific surface area and total pore volume of coal. The increase in specific surface area, total pore volume, and D-1 has negative effects on the slurry ability of coal. High-rank coals with high ash content and low volatile matter relatively have higher Di and lower D-2. Meanwhile, with increasing coal rank, D-2 has a decreased trend. The fine mesopores with an average pore size range of 2 nm to 10 nm in coal have direct effects on the pore structure parameters and D-2 of coal; thus, the slurry ability of coal may be improved if the number of these mesopores in coal is reduced by modification processes, such as microwave irradiation, hydrothermal treatment and so on. (C) 2016 Elsevier B.V. All rights reserved.