35 resultados para (H2S HS- S2-)

em Chinese Academy of Sciences Institutional Repositories Grid Portal


Relevância:

20.00% 20.00%

Publicador:

Resumo:

(HSSPME),SPME(PDMS,PMPVS,PA),,,DDT.,SPME,PDMS,DDT.

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Relevância:

20.00% 20.00%

Publicador:

Resumo:

(GLDM)WKB~(263)Hs~(260)Bh,:WKB,,,~(260)Bh~(263)Hs

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The ground-state properties of Hs nuclei are studied in the framework of the relativistic meanfield theory. We find that the more relatively stable isotopes are located on the proton abundant side of the isotopic chain. The last stable nucleus near the proton drip line is probably the (255)Hs nucleus. The alpha-decay half-lives of Hs nuclei are predicted, and together with the evaluation of the spontaneous-fission half-lives it is shown that the nuclei, which are possibly stable against spontaneous fission are (263-274)Hs. This is in coincidence with the larger binding energies per nucleon. If (271-274)Hs can be synthesized and identified, only those nuclei from the upper Z = 118 isotopic chain, which are lighter than the nucleus (294)118, and those nuclei in the corresponding alpha-decay chain lead to Hs nuclei. The most stable unknown Hs nucleus is (268)Hs. The density-dependent delta interaction pairing is used to improve the BCS pairing correction, which results in more reasonable single-particle energy level distributions and nucleon occupation probabilities. It is shown that the properties of nuclei in the superheavy region can be described with this interaction.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The deformed doubly magic nucleus (270)Hs has so far only been observed as the four-neutron (4n) evaporation residue of the reaction Mg-26+Cm-248, where a maximum cross section of 3 pb was measured. Theoretical studies on the formation of (270)Hs in the 4n evaporation channel of fusion reactions with different entrance channel asymmetry in the framework of a two-parameter Smoluchowski equation predict that the reactions Ca-48+Ra-226 and S-36+U-238 result in higher cross sections due to lower reaction Q values, in contrast to simple arguments based on the reaction asymmetry, which predict opposite trends. Calculations using HIVAP predict cross sections for the reaction S-36+U-238 that are similar to those of the Mg-26+Cm-248 reaction. Here, we report on the first measurement of evaporation residues formed in the complete nuclear fusion reaction S-36+U-238 and the observation of (270)Hs, which is produced in the 4n evaporation channel, with a measured cross section of 0.8(-0.7)(+2.6) pb at 51-MeV excitation energy. The one-event cross-section limits (68% confidence level) for the 3n, 4n, and 5n evaporation channels at 39-MeV excitation energy are 2.9 pb, while the cross-section limits of the 3n and 5n channel at 51 MeV are 1.5 pb. This is significantly lower than the 5n cross section of the Mg-26+Cm-248 reaction at similar excitation energy.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The reactions of both thiophene and H2S onMo(2)C/Al2O3 catalyst have been studied by in situ FT-IR spectroscopy. CO adsorption was used to probe the surface sites of Mo2C/Al2O3 catalyst under the interaction and reaction of thiophene and H2S. When the fresh Mo2C/Al2O3 catalyst is treated with a thiophene/H-2 mixture above 473 K, hydrogenated species exhibiting IR bands in the regions 2800-3000 cm(-1) are produced on the surface, indicating that thiophene reacts with the fresh carbide catalyst at relatively low temperatures. IR spectra of adsorbed CO on fresh Mo2C/Al2O3 pretreated by thiophene/H-2 at different temperatures clearly reveal the gradual sulfidation of the carbide catalyst at temperatures higher than 473 K, while H2S/H-2 can sulfide the Mo2C/Al2O3 catalyst surface readily at room temperature (RT). The sulfidation of the carbide surface by the reaction with thiophene or H2S maybe the major cause of the deactivation of carbide catalysts in hydrotreating reactions. The surface of the sulfided carbide catalyst can be only partially regenerated by a recarburization using CH4/H-2 at 1033 K. When the catalyst is first oxidized and then recarburized, the carbide surface can be completely reproduced.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Hydrogen sulfide (H2S) production patterns and the influence of oxygen (O-2) concentration were studied based on a well operated composting plant. A real-time, online multi-gas detection system was applied to monitor the concentrations of H2S and O-2 in the pile during composting. The results indicate that H2S was mainly produced during the early stage of composting, especially during the first 40 h. Lack of available O-2 was the main reason for H2S production. Maintaining the O-2 concentration higher than 14% in the pile could reduce H2S production. This study suggests that shortening the interval between aeration or aerating continuously to maintain a high O-2 concentration in the pile was an effective strategy for restraining H2S production in sewage sludge composting. (C) 2010 Elsevier Ltd. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

It is reported for the first time that the performance of the electrochemical H2S sensor with the Nation membrane pre-treated with the concentrated H2SO4 as the solid electrolyte is much more stable than that for the sensor with the Nation membrane without H2SO4 pretreatment. The sensitivity of the sensor is about 2.92 muA/ppm. The response time of the sensor is about 9 s. The detection limit is about 0.1 ppm. Therefore, this kind of the electrochemical H2S gas sensor may be desirable for the practical application.