摘要:

13C NMR spectra of lumisantonin (2), isosantoxane (3a), its acetyl derivative (3b) and santonic acid (4) are reported. The structure of a novel photo derivative (6) is established on the basis of spectroscopic methods, particularly13C NMR spectra.

ISSN:0038-7010    

DOI:10.1080/00387019208021530

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A method called “Spectral K-ratio spectrophotometry” was proposed. The method takes the K-coefficient dual-wavelength spectrophotometric method as the mathematical model in order to resolve the different nth-derivative spectral data at one wavelength to determine certain two components systems that their zeroth- (absorption) and nth-derivative spectra were all interfered seriously. Examples of the application of the proposed method were given.

ISSN:0038-7010    

DOI:10.1080/00387019208021531

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The mode using the two-line method based on fiber optics to measure flame temperature by a rapid-scanning spectrometer is presented. The measurement system developed by us useful for remote measurement or to carry an optical signal in and out of environments like too low or too high temperatures, high magnetic field etc. is described in detail. The technique is discussed and compared with other methods in flame spectroscopy. Our results show that the advantages of this method are very sensitive, flexible, rapid, convenient and accurate. The further applications such as using the method in automation design or process automation are also discussed.

ISSN:0038-7010    

DOI:10.1080/00387019208021532

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Two methods for the spectrophotometric determination of uranium (VI) are described. The methods are based on the formation of colored complexes for uranium (VI) with (1)di-2-pyridyl ketone nicotinoylhydrazone (DPKNH), and (2)di-2-pyridyl ketone thiophenoylhydrazone (DPKTH) in 50% (v/v) ethanolic solution. The complexes formed a uranium (VI): complexing reagent mole ratio of 1:2. Maximum absorbance is at 373 nm for U(VI)DPKNH, and at 389 nm for U(VI) - DPKTH. Ranges of linearity, effect of pH, effect of excess reagent, stability of the complexes, and the tolerance limit for many metal ions and common anions have been reported. The two methods have been applied to the determination of uranium in eygeptian monazite sand.

ISSN:0038-7010    

DOI:10.1080/00387019208021533

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

The complexes of Eu(III) and the Schiff bases were obtained and the structure, nature of chemical bonds, and symmetry of the compounds were eluciaded on the basis of spectroscopic and elemental analysis data. Two of the compounds were the monomers with 8-coordinated europium and one of them was a dimer with 6-coordinated europium.

ISSN:0038-7010    

DOI:10.1080/00387019208021534

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

IR spectra were taken of NiSO4. nH2O (n = 7,6,4,1,0) and of the fully and partially deuterated analogues of theirs in the region of 4000 cm−1to 300 cm−1in tablets of KBr, in Nujol in the region of 4000 cm−1to 500 cm−1, and in suspension of 1,3-hexachlorobutadiene from 4000 to 1000 cm−1. They were interpreted in relation to the stretching and bending vibrations of the hydrate water, its symmetry, the types of H bonds in which it participates (H2O – – – H - O - H – – – OSO3and H2O - - H - O - H – – – OH2) and their energy. The latter, calculated from spectroscopic data, varies within the interval of 32 - 22 kJ/mol for NiSO4.nH2O (n = 7,6,4) and is 38.9 kJ/mol for NiSO4.H2O. Correlation has been established between the E of the H bond and d(Ni ← 0). The librational vibrations were characterized mainly by the respective composite vibrations. (νL+ δH2O). The symmetry of the SO4group has been examined and compared in the various hydrates, as well as its bidentate coordination in the monohydrate.

ISSN:0038-7010    

DOI:10.1080/00387019208021535

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue.

ISSN:0038-7010    

DOI:10.1080/00387019208021519

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor