Time profiles of weight change of coal samples and the evolution of low molecular weight gases (H2, CH4, CO and CO2) in both steam gasification and pyrolysis of Yallourn brown coal and Taiheiyo subbituminous coal were measured using a thermobalance reactor with a micro GC and a mass spectrometer, in order to examine the reaction mechanism of steam gasification with rapid heating (100 K s−1). It was found that, in the case of slow heating, steam reacted with metaplast and promoted the evolution of tar above 623 K and that a water shift reaction took place above 873 K. Steam gasification of produced char occurred above 1023 K, increasing the evolution of CO, CO2 and H2. When the heating rate was high, steam reforming of volatile matter and steam gasification of metaplast took place parallel to metaplast formation and condensation. The char produced by pyrolysis was almost completely gasified and converted into H2 and CO2 by steam. The chemical energy of coal was mainly converted into hydrogen energy and the gasification efficiency was slightly increased by rapid heating (i.e. 100 K s−1). 相似文献
Flexible polyurethane foam was decomposed into a polyol mixture by an extruder with diethanolamine (DEA) as a decomposing agent. The resulting decomposed product could be used as an alternative virgin polyol in reclaiming polyurethane. In the case of reclaiming elastomer by using the decomposed product without any purification, virgin polyol could be alternated by the decomposed product up to 80%. It is a great improvement compared with the reclamation to foam, whose percentage was maximum 5%. Furthermore, the percentage could be improved up to 100% by purifying the decomposed product. We have found that physical properties of reclaimed polyurethane elastomer, such as tensile strength, hardness, and elongation, can be regulated by the ratio of unrefined/refined polyol. Whereas the tensile strength and the hardness increased as the content increased, the elongation decreased. 相似文献
We have developed a highly sensitive method for the simultaneous determination of individual bile acids in serum using high-performance liquid chromatography (HPLC) combined with immobilized 3 alpha-hydroxysteroid dehydrogenase. Both the HPLC column and the immobilized-enzyme column are suitable for use with alkaline solutions necessary in working with this enzyme system. With this method we were able to determine simultaneously fifteen different serum bile acids. 相似文献
We consider a billiard model of a self-bound, interacting three-body system in two spatial dimensions. Numerical studies show that the classical dynamics is chaotic. The corresponding quantum system displays spectral fluctuations that exhibit small deviations from random matrix theory predictions. These can be understood in terms of a new type of scarring caused by a one-parameter family of orbits inside the collinear manifold. 相似文献
The MOON (Majorana/Mo Observatory Of Neutrinos) project aims at studies of the Majorana nature of the neutrino (ν) and the ν-mass spectrum by spectroscopic experiments of neutrino-less double beta decays (0νββ) with the ν-mass sensitivity of 〈mνm〉 = 100−30 meV. The solid scintillator option of the MOON detector is a super ensemble of multi-layer modules, each being
composed by PL scintillator plates and position-sensitive detector planes with good overall energy resolution of σ ≈ 2% at the Qββ ≈ 3 MeV. Thin ββ source films are interleaved between the detector planes. High localization of the two β tracks enables one to select true signals and reject BG ones. The multi-layer structure of the detector makes it realistic
to build a compact ton-scale detector. MOON with detector ≠ ββ source is used for studying 0νββ decays from 100Mo, 82Se and other ββ isotopes with large Qββ. Real-time exclusive measurements of low energy solar neutrinos can be made by observing inverse β rays from solar-ν captures of 100Mo in delayed coincidence with the subsequent β decay of 100Tc. 相似文献
For accurate quantification of polycyclic aromatic hydrocarbons (PAHs) in dust samples, we investigated the use of microwave-assisted solvent extraction (MAE) combined with isotope-dilution mass spectrometry (IDMS) using deuterium-labelled PAHs (D-PAHs). Although MAE with a methanol/toluene mixture (1:3 by volume) at 160 °C for 40 min was best for extracting PAHs from tunnel dust among examined, the recovery yields of D-PAHs decreased with increasing molecular weight (<40% for MW ≥ 264; that of deuterium-labelled indeno[123-cd]pyrene (D-IcdP) was only 7.1%). Although the residues were extracted a second time, the observed concentrations did not change dramatically (<5%), and the recovery yields of heavier D-PAHs (i.e., MW ≥ 264) were approximately half of those of the first extract, including D-IcdP (3.4%). These results suggest that both partitioning and isotopic equilibria of PAHs and D-PAHs between sample and solvent were achieved for extractable heavier PAHs under the condition. Thus, the observed concentrations of PAHs obtained by MAE–IDMS were reasonable, even though recovery yields of D-PAHs were <50%. From the results of carbon analyses and extractable contents, lower recovery yields of D-PAHs from the tunnel dust were due to a large content of char with low extractable contents. 相似文献
Five novel compounds (1–3, 5, and 6), and two known ones (4 and 7) were isolated from the culture broth of Agrocybe praecox. Their structures were determined by the interpretation of spectroscopic data. Compounds 1–4 inhibited hypocotyl growth of lettuce, and 1, 3, and 4 inhibited the root growth. 相似文献
[Structure: see text] A new Br?nsted acid-assisted chiral Br?nsted (chiral BBA) acid catalyst (1) was developed by substituting a hydroxy group of optically active 1,1'-bi(2-naphthol) with a stronger Br?nsted acidic group such as a bis(trifluoromethanesulfonyl)methyl group. The enantioselective Mannich-type reaction of ketene silyl acetals with aldimines catalyzed by (R)-1 in the presence of stoichiometric achiral proton sources gave (S)-beta-amino esters in high yield with moderate to good enantiomeric excesses. 相似文献
Five novel compounds, applanatines A-E (1-5), and a known one (6) were isolated from the culture broth of Ganoderma applanatum. Their structures including the relative configurations were determined by the interpretation of spectroscopic data. Compounds 3 and 4 suppressed the growth of Fusobacterium nucleatum, that is, a prominent member of the oral microflora implicated in periodontitis. 相似文献
To the limit : Electrolyte flow accelerates the mass‐transfer process in a droplet cell (see picture). The limiting current in the cell is expressed as a sum of hydrodynamic and stagnant terms. The current derived from the latter term indicates that convective mass transfer in the cell would be changed dramatically at a significantly small volumetric flow rate.