Peculiarly shaped chromatograms of some compounds that consist of two reversible isomers have been reported. Those of a compound that consists of three reversible isomers are described here. Because disulfide of captopril has two cistrans convertible bonds, it exists in three forms of cis-cis, cis-trans and trans-trans isomers. The disulfide has produced various HPLC-UV profiles under various conditions, such as three split peaks, three peaks with bridging plateaus and one broad peak. The effect of the column temperature and the eluent flow rate on the profile was investigated and explained by interconversion among three isomers. A profile analysis could provide some kinetic constants of this reaction.

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We investigated hydration and strength developrnent of cementitious materials cured under freezing or drying condi ・ tion experimentall γ The test results show that hydration and stren 匹 h development depend onboth tenΨ erature and chemical potential ofwater ． Theoretical study makes it clear that e飩 ct oftemperature fblows the Arrhenius equation and the activation energy in the equation is proportion 湿 to the decrease of chemical potentia1 ． Consequently the equivalent maturity method that describes the rate ofhydration under dryin 匿 a皿 d freezing condi ・ tion was proposed ． ffeywords ；hydration rate ， strength development ， hydratien ratio ， chemical potential， maturity method

In this paper， air entraining properdes of fly ash concrete was investigated experimentally ， and Im os 廿mation method of the desage of air entraining agent f (｝ r fly ash concrete was propOsed ， The resu 星 ts sbows that 血 e re(IUired dosage of air entraining agent in fiy ash concrete was 皿 uch higher than that in o 「dinafy oonCfete ． In the estimation method ． ny ash co 皿 tent is cha 皿 ged to cement content equivalent value using basic properties of fly ash ， and dosage of air entraining agent is calculated ． And it appeals thauhe 皿 e 血 od is usefUl when us 孟 ng absorptio 皿 weight of methylene b【 ue as the basic prope 感 y ． keyWOids ； fly ash ， air entraining ， air entrainin8 agent ， absorption wei8ht ofn 昭 thylene blue

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