The process of desorption for the system of O,/Pd( 111) under excitation by 100 fs pulses of visible light has been examined. Molecular desorption is found to occur with high efficiency and a nonlinear dependence on laser fluence. Direct time-domain measurements using a two-pulse correlation scheme reveal a dominant subpicosecond response together with a weaker, but significant correlation pers...

2014 The correlation between the intrinsic luminescence of solid argon excited by slow electrons (a few eV to 100 eV) and desorption was studied. Related to exciton creation, a sharp threshold of desorption and of luminescence is observed at the same energy of the impinging electrons. The desorption rate is proportional to the exciton density at the surface. The surface nature of different lumi...

In this paper, rapid freezing and thawing test of air-entrained fly–ash concrete was carried out. Gas adsorption of concrete pores, mass loss, dynamic elastic modulus, and chloride diffusion coefficient of concrete after different freezing and thawing cycles was tested; scanning electron image was used to study the microscopic pore structure of the specimens. Results show that after certain fre...

The enantiospecific adsorption and desorption of (R)-3-methylcyclohexanone on naturally chiral Cu(531) surfaces was studied using temperature programmed desorption. The Cu(531) surfaces are of interest because they lie at the center of the stereographic triangle and thus, have the highest density of chiral adsorption sites possible on the surface of a face centered cubic metal. Several (R)-3-me...

The adsorption/absorption of hydrogen and the adsorption of carbon monoxide by niobium foils, at room temperature, was studied using thermal desorption spectroscopy. Two hydrogen desorption peaks were observed with a maximum at 404 and 471 K. The first hydrogen desorption peak is regarded as hydrogen desorbing from surface sites while the second peak, which represents desorption from surface si...

Stirred-flow cell experiments were performed to investigate the kinetics of uranyl [U(VI)] desorption from a contaminated sedimentcollected from the Hanford 300 Area at the U.S. Department of Energy Hanford Site, Washington. Three influent solutions of variable pH, Ca and carbonate concentrations that affected U(VI) aqueous and surface speciation were used under dynamic flow conditions to evalu...

The desorption kinetics of hexachlorobenzene (HCB) and 2,4,4'-trichlororbiphenyl (PCB 28) spiked to a field sediment were studied using a gas-purge technique. A contact time of up to 1,461 d was used to assess long-term changes in desorption kinetics. Purge-induced desorption experiments lasted from 300 to more than 4,000 h. Fast-, slow-, and very-slow-desorbing fractions could be distinguished...

Reflection absorption infrared spectroscopy (RAIRS) and temperature programmed desorption (TPD) have been used to investigate the adsorption of methanol (CH(3)OH) on the highly oriented pyrolytic graphite (HOPG) surface. RAIRS shows that CH(3)OH is physisorbed at all exposures and that crystalline CH(3)OH can be formed, provided that the surface temperature and coverage are high enough. It is n...

The desorption of phosphate from aluminum (Al) hydroxides by 0.01 mol L KCl in the presence of different organic acids and from Al-OH, Al-P and Al-Oxalate, AlCitrate complexes by organic acids was studied. When phosphate adsorbed on Al(OH)x in the presence and absence of oxalate was desorbed sequentially twice using 0.01 mol L KCl, total desorption rates of phosphate adsorbed in the presence of...