scholarly journals Hydroxyl-concentration distribution near the binding interface formed by heating contacted flat silica glass surfaces at high temperature

2009 ◽  
Vol 117 (1362) ◽  
pp. 211-213 ◽  
Author(s):  
Nobu KUZUU ◽  
Hideharu HORIKOSHI ◽  
Akihide OKAZAKI ◽  
Tomoya SEKI ◽  
Mitsuya TANAKA
1969 ◽  
Vol 47 (8) ◽  
pp. 1375-1379 ◽  
Author(s):  
Michie Shimizu ◽  
H. D. Gesser ◽  
M. Fujimoto

The electron spin resonance (e.s.r.) spectra of •CH3, •CHO, H and/or D, and possibly •CH2OH or •CH2OD were found by the ultraviolet (u.v.) photolysis of methanol —OH or —OD on porous high-silica glass at 77 °K. These e.s.r. spectra resemble the results of the u.v. photolysis of X-irradiated methanol indicating that some perturbation and/or sensitization occurred in the molecules by the glass surface. The absence of e.s.r. spectra from the same systems on the acid-leached glass, on the totally fluorinated glass, or on the totally —OH covered glass suggests that (i) the co-existence of surface contaminants, such as Al and Zr and not B, and some of surface —OH could be responsible for producing these free radicals, and (ii) the methanols adsorbed on these glass surfaces are stabilized against u.v. photolysis.


1961 ◽  
Vol 39 (6) ◽  
pp. 1221-1230 ◽  
Author(s):  
J. G. Hooley

A method is presented for preparing a reproducible silica glass or quartz surface that does not craze during rate of solution measurements in solutions of the five group I hydroxides. For silica glass, initial rates are a maximum at 8 M for at least NaOH and KOH and are an inverse function of ion size for the five cations and tetramethyl ammonium ion. A proposed mechanism of water addition followed by reaction with hydroxyl ion is used to explain the maximum rate and the effect of solution products and the substitution of methanol for water as a solvent. For quartz an explanation is offered for the lower rate and for the absence of a maximum rate below 27 M NaOH. A common temperature coefficient of 20 kcal mole−1 is reported for all reactions in water. The crazing of finely ground or polished silica glass surfaces is related to the presence of surface cracks and their enlargement by possible conversion of some silica to quartz in NaOH solution.


2017 ◽  
Vol 36 (9) ◽  
pp. 885-890
Author(s):  
Shuying Chen ◽  
Guowei Chang ◽  
Xudong Yue ◽  
Qingchun Li

AbstractIn this study, a Cu/Al composite ingot was prepared by casting aluminum method, and the effects of the Cu concentration distribution in the transition layer on the solidification microstructure were examined during the recombination process of solid Cu and liquid Al. The results show that the Cu content is about 60 % at the Cu/Al binding interface in the transition layer, while the Cu concentration first drops sharply and then decreases slowly in the direction away from the pure Cu. The concentration gradient of Cu reaches 1 %/μm close to the Cu/Al binding surface. The Cu distribution in the transition layer does not change the microstructure species, but changes the proportions of various microstructures. The smaller the Cu concentration gradient is, the less the proportion of the hypoeutectic microstructure in transition layer is.


2002 ◽  
Vol 197-198 ◽  
pp. 50-55 ◽  
Author(s):  
Y Kawaguchi ◽  
A Narazaki ◽  
T Sato ◽  
H Niino ◽  
A Yabe ◽  
...  

1991 ◽  
Vol 30 (Part 1, No. 8) ◽  
pp. 1854-1859 ◽  
Author(s):  
Keiji Oyoshi ◽  
Takashi Tagami ◽  
Shuhei Tanaka

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