摘要:

The CD spectra of simple derivatives, di- and tripeptides containing phenylalanine and β-homophenylalanine (β-Hph)** at their C-terminals were studied. The reverse sign contribution of the aromatic1Latransition of β-homophenylalanine in comparison of phenylalanine was found. The implication of this hitherto undescribed fact is discussed in relation to a diagnostic value of the CD measurements in spectral region 200–240 nm.

ISSN:0038-7010    

DOI:10.1080/00387019008054412

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A rapid spectrophotometric method for the analysis of chlorphenoxamine hydrochloride in combination with unhydrous caffeine was described. The method is based on the determination of chlorphenoxamine hydrochloride byat 225 and 232 nm while unhydrous caffeine recorde zero at the same wave lengths. Unhydrous caffeine determined byat 256 and 283 nm which corresponding to zero reading for chlorphenoxamine hydrochloride.

ISSN:0038-7010    

DOI:10.1080/00387019008054413

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

After an extensive study of line shifts and widths of one and two times ionized noble gases, we found simple empirical relations betweens such quantities (when multiplied by the respective atomic number, Z) and the inverse of the upper level ionization potential, I. In the adjustment process, a high value for the correlation coefficient is obtained. Thus, Z and I−1are relevant atomic parameters for Stark line shifts and widths.

ISSN:0038-7010    

DOI:10.1080/00387019008054414

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Infrared absorption spectra of cycloheptanol-OH have been measured in the 50–3700 cm−1frequency range for crystal II', II, I and liquid phases. Order-disorder behaviour concerning orientational, conformational and hydrogen-bond properties is discussed.

ISSN:0038-7010    

DOI:10.1080/00387019008054415

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Racemic rimantadine,1, has been studied by NMR in CDC13solution with the achiral shift reagent

ISSN:0038-7010    

DOI:10.1080/00387019008054416

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Raman spectra have been measured and structurally interpreted for YBa2Cu3O7-ytreated by different types of fluorine additions, including both initially doping appropriate fluorides into the starting materials to be fired, and NF3treating of the pure superconductor oxide. Both x-ray diffraction and low-temperature inductance measurements have also been conducted. All presented data indicated that phase impurities were generated during the former processes. However, related data indicated that NF3treatment of the pure oxide samples generated no new crystalline phases, but caused substitution or addition of F at O sites in the oxide phase.

ISSN:0038-7010    

DOI:10.1080/00387019008054417

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The water proton T1 in human blood diluted by its own plasma was measured with a FT-NMR spectrometer operating at 60MHz for protons. A linear relationship (with a correlation of 0.99) was found between the 1/T1 and hemoglobin content(Hb) in the blood. The exchange of water between the extracellular plasma and the intracellular Hb in blood is known to satisfy the fast chemical exchange conditions, and the decay of magnetization in blood is reported to have a single exponential. Therefore, the obtained relationship should represent fast chemfcal intracellular Hb and the extrace exchange between the lular plasma.

ISSN:0038-7010    

DOI:10.1080/00387019008054418

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Two dimensional HETCOR and long range HETCOR experiments have been performed on the natural coumarins hopeyhopin, dehydrogeijerin, 6-methoxy-7-(3′,3′-dimethylallyloxy)-coumarin, puberulin, oxypeucedanin and isoimperatorin which allowed complete1H and13C spectral assignments to be made.

ISSN:0038-7010    

DOI:10.1080/00387019008054419

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

The necessity of geometry optimization within the framework of a particular molecular orbital technique is demonstrated using the INDO and EHMO semiempirical methods. The difficulty of finding the global minimum and the proper choice of technique is also discussed. The choice of molecules demonstrates that structure optimization can completely reverse the prediction of which conformer has the lowest energy.

ISSN:0038-7010    

DOI:10.1080/00387019008054420

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Emission resulting from collisions of 100–1000 eV He· and He2· ions with CH3HgBr molecules has been characterized in the 244–580 nm region. Emission bands due to HgBr (B-X), CH(A-X), and CH(B-X) transitions were observed besides atomic mercury lines. Emission cross-sections as a function of energy of helium ions for the strongest band of HgBr radical at 502 nm corresponding to the transition (v' = 0 − v′ = 22) were determined.

ISSN:0038-7010    

DOI:10.1080/00387019008054421

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor