摘要:

The infrared spectra of the Nd:YAG laser rods have been studied at 300˚K in the spectral region 2400 cm−1- 4000 cm−1and assignments of the observed frequencies to different absorption modes have been proposed. It has been demonstrated that commercial laser rods entrain trace amounts of impurity water in the crystal network. The absorbed water is present both in molecular form and in the form of hydroxyl groups linked by hydrogen bonding to the oxygen matrix, rather than to water molecules.

ISSN:0038-7010    

DOI:10.1080/00387018208068246

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The mucohalic acids are a group of organic compounds whose structures have been the subject of a good deal of investigation and controversy in recent years. These compounds can undergo a tautomeric ring closure and both structures I and II have been claimed to be predominant by various workers using various chemical and instrumental techniques. (X = halogen)

ISSN:0038-7010    

DOI:10.1080/00387018208068247

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

During the last decade much effort has been made to the synthesis of new mesomorphic materials with suitably low melting points for display application. The extensive work by Gray and coworkers /1/ has established that the cyanobiphenyl system with alkyl and alkoxy substituents create stable, colourless, low melting liquid crystals. Naturally, it would be of some importance for the practice to know the orientational properties of these species charties characterized by the orientational order parameters ⟨P2= 1/2 ⟨cos2- 1⟩ and ⟨P4= 1/3 ⟨35 cos2- 30 cos2→ 3⟩ where is the angle between the long exis of any given molecules with the direction of the molecular given molecules witn tne direction of the molecular alignment. The angular brackets denote averaging over all molecules in tne medium. First Heger /2/ and later Miyano /3/ using Haman spectroscopical method have reported tne ⟨P2⟩ and ⟨P4⟩ temperature dependence for tne nematic liquid cryetals 4-cyan0 4′n-pentylbipnenyl and 4-cyan0 4′n-neptylbiphenyl correspondingly. Comparative studies of the orientational order parameters ⟨P2⟩ determined by IR and FIR spectroscopy of some 4-cyano alkylbipnenyls have been also reported recently /4/. Elastic and optical properties of 4-CYanO 4′n-pentyl to 4′n-octylbiphenyls as well as ⟨P2⟩ temper-ature dependence nave been published i n refs. 5a,b. In spite of the much research work already done on 4-cyan0 4′n-alkylbipnenyls ⟨P2⟩ of only one alkoxycya-nobipnenyl derivative namely 4-cyan0 4′n-octyloxybi-phenyl has been measured by IR absorption spectroscopy /6/ and by EPR technique /7/.

ISSN:0038-7010    

DOI:10.1080/00387018208068248

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Photoacoustic spectroscopy is shown to be a novel instrumental method for studying the kinetics of a slow, solid-state reaction between two solids to form a solid, charge transfer complex. A two stage mechanism for the reaction between solid anthracene and solid picric acid is proposed to explain, the photoacoustically measured, spectra for the growth of the charge transfer complex.

ISSN:0038-7010    

DOI:10.1080/00387018208068249

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Lanthanide shift reagents provide a powerful aid to nmr spectroscopy for the evaluation of the structures of organic compounds.2Whether used for qualitative simplification of nmr spectra or for rigorous mathematical analysis of a proposed structure,3–5shift reagents are most effectively utilized when the association equilibria are well understood. A lanthanide shift reagent (L) can coordinate to either one or two molecules of substrate (S) according to equations (1) and (2).

ISSN:0038-7010    

DOI:10.1080/00387018208068250

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

This paper presents a simple and effective method for obtaining the beam density, that is the number of atoms per unit volume of the beam, by measuring the change in the electrical resistance of a uniform strip of iron which is placed in the beam.

ISSN:0038-7010    

DOI:10.1080/00387018208068251

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

A comparative investigation was carried out of the suitability of atomic absorption spectrometry and of emission spectrography with hollow cathode and arc excitation sources for determination of aluminium in biological samples. The three methods give reliable results. Hollow cathode emission spectrography was found to be influenced to a lesser extent by matrix effects than the other two techniques. On the other hand atomic absorption spectrometry presents some remarkable advantages insofar rapidity of analysis and detection limits are concerned.

ISSN:0038-7010    

DOI:10.1080/00387018208068252

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The absorption spectrum of manganese formate dihy-drate has been studied at liquid nitrogen temperature (80 K) in the region λ 650 nm to 300 nm. Three bands of the spectrum resolved themselves exhibiting fine structure. The splitting of the4Eg(G) band is explained as due to exciton-magnon interaction. Weak bands on either side of4A1g(G) band are assigned to phonon progressions with = 0.12 kK. The fine structure of the4T2g(D) band is explained as due to spin-orbit interaction. The observed band positions are fitted to four parameters B, C, ηq and α the best fit being obtained with B = 0.82 kK; C = 3.02 kK; Dq = 0.81 kK; α = 0.076 kK.

ISSN:0038-7010    

DOI:10.1080/00387018208068253

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

ISSN:0038-7010    

DOI:10.1080/00387018208068254

出版商:Taylor & Francis Group    

年代:1982

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:10.1080/00387018208068245

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor