Determination of a differential pencil from interior spectral data on a union of two closed intervals

2021 ◽  
Keyword(s):  
Spectral Data ◽  
Closed Intervals

21,22-Disubstituted 18α,19βH-Ursane Derivatives with Oxabicyclooctane System in Ring E

1993 ◽  
Vol 58 (1) ◽  
pp. 173-190 ◽  
Author(s):  
Eva Klinotová ◽  
Jiří Klinot ◽  
Václav Křeček ◽  
Miloš Buděšínský ◽  
Bohumil Máca
Keyword(s):  
Spectral Data ◽  
Spin Systems ◽  
Coupling Constants ◽  
Complete Analysis ◽  
Nmr Spectrum ◽  
Proton Proton ◽  
H Nmr ◽  
Proton Coupling ◽  
C Nmr

Reaction of 3β-acetoxy-21,22-dioxo-18α,19βH-ursan-28,20β-olide (IIIa) and 20β,28-epoxy-21,22-dioxo-19α,19βH-ursan-3β-yl acetate (IIIb) with diazomethane afforded derivatives XII-XIV with spiroepoxide group in position 21 or 22, which were further converted into hydroxy derivatives XV and XVII. Ethylene ketals VIII-X were also prepared. In connection with the determination of position and configuration of the functional groups at C(21) and C(22), the 1H and 13C NMR spectral data of the prepared compounds are discussed. Complete analysis of two four-spin systems in the 1H NMR spectrum of bisethylenedioxy derivative Xb led to the proton-proton coupling constants from which the structure with two 1,4-dioxane rings condensed with ring E, and their conformation, was derived.

scholarly journals Determination of differential pencils with impulse from interior spectral data

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Yongxia Guo ◽  
Guangsheng Wei ◽  
Ruoxia Yao
Keyword(s):  
Spectral Data ◽  
Interior Point ◽  
Potential Functions ◽  
Inverse Spectral Problems ◽  
Spectral Problems ◽  
Inverse Spectral ◽  
Differential Pencils ◽  
Second Spectrum

Abstract In this paper, we are concerned with the inverse spectral problems for differential pencils defined on $[0,\pi ]$ [ 0 , π ] with an interior discontinuity. We prove that two potential functions are determined uniquely by one spectrum and a set of values of eigenfunctions at some interior point $b\in (0,\pi )$ b ∈ ( 0 , π ) in the situation of $b=\pi /2$ b = π / 2 and $b\neq \pi /2$ b ≠ π / 2 . For the latter, we need the knowledge of a part of the second spectrum.

Determination of an impulsive diffusion operator from interior spectral data

Analysis ◽  
2020 ◽  
Vol 40 (1) ◽  
pp. 39-45
Author(s):  
Yasser Khalili ◽  
Dumitru Baleanu
Keyword(s):  
Inverse Problem ◽  
Spectral Data ◽  
Potential Functions ◽  
Half Line ◽  
Internal Point ◽  
Diffusion Operator ◽  
Impulsive Diffusion

AbstractIn the present work, the interior spectral data is used to investigate the inverse problem for a diffusion operator with an impulse on the half line. We show that the potential functions {q_{0}(x)} and {q_{1}(x)} can be uniquely established by taking a set of values of the eigenfunctions at some internal point and one spectrum.

Synthesis of 4-(3-coumarinyl)-3-benzyl-4-thiazolin-2-one 4-methylbenzylidenehydrazone and determination of the isomeric structure by X-ray analysis

2003 ◽  
Vol 218 (12) ◽  
Author(s):  
Süheyla Özbey ◽  
Nilgün Karalı ◽  
Aysel Gürsoy
Keyword(s):  
Single Crystal ◽  
Diffraction Analysis ◽  
Spectral Data ◽  
X Ray Diffraction ◽  
X Ray ◽  
Isomeric Structure ◽  
Elemental Analyses

AbstractIn this study 4-(3-coumarinyl)-3-benzyl-4-thi azolin-2-one 4-methylbenzylidenehydrazone 3 was synthesised. An independent proof of the thiazolylhydrazone structure of 3 was achieved by single crystal X-ray diffraction analysis. Elemental analyses and spectral data (IR,

Elucidation of Polymer Microstructure by High Resolution NMR Spectroscopy

1967 ◽  
Vol 40 (2) ◽  
pp. 385-399 ◽  
Author(s):  
Raymond C. Ferguson
Keyword(s):  
Nmr Spectroscopy ◽  
High Resolution ◽  
Spectral Data ◽  
High Field ◽  
Structural Features ◽  
Polymer Microstructure ◽  
Structural Isomerism ◽  
High Resolution Nmr ◽  
Polymer Tacticity

Abstract High resolution NMR spectroscopy is proving to be a useful experimental technique for determining the microstructures of high polymers. Its major utility, aside from identifying structural features often not detectable by other methods, lies in quantitative applications. Some examples are the determination of monomer ratios in copolymers, polymer tacticity, sequence isomerism of monomer units, and other types of structural isomerism. The applicability of the method is being enhanced by continuing development of high-field spectrometers, special accessories, and new experimental techniques, and by application of computers to the analysis of spectral data.

Microdetermination of Bioethanomethrin

1975 ◽  
Vol 58 (4) ◽  
pp. 781-784
Author(s):  
Donald A George ◽  
Leslie M Mcdonough
Keyword(s):  
Spectral Data ◽  
Electron Capture ◽  
Synthetic Pyrethroid ◽  
Pyrethroid Insecticide ◽  
Electron Capture Detector ◽  
Gas Chromatograph ◽  
Mass Spectral Data ◽  
Acid Moiety ◽  
Mass Spectral

Abstract A microanalytical method was developed for the determination of the experimental synthetic pyrethroid insecticide Bioethanomethrin ((5- benzyl-3-furyl) methyl trans-(+)-3-( cyclopentylidenemethyl)-2,2 -dimethylcyclopropanecarboxylate). After saponification, trichloroacetyl chloride is used to form an ester from the alcohol moiety, and trichloroethanol is used to form an ester from the acid moiety. Infrared and mass spectral data support the expected structures of the derivatives formed. Nanogram sensitivity is realized by utilizing a gas chromatograph with an electron capture detector.

Synthesis, spectral description, and lipophilicity parameters determination of phenylcarbamic acid derivatives with integrated N-phenylpiperazine moiety in the structure

2006 ◽  
Vol 60 (1) ◽  
Author(s):  
I. Malík ◽  
E. Sedlárová ◽  
J. Csöllei ◽  
F. Andriamainty ◽  
P. Kurfürst ◽  
...  
Keyword(s):  
Neural Network ◽  
Spectral Data ◽  
1H Nmr ◽  
Elemental Analysis ◽  
Computer Programs ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
The Neural Network ◽  
Lipophilicity Parameters

AbstractThe phenylcarbamic acid derivatives with N-phenylpiperazine moiety in the molecule have been prepared. The structure has been confirmed by elemental analysis, IR, 1H NMR, and mass spectral data. For the prepared set of the compounds the lipophilicity parameters have been determined. The experimentally obtained lipophilicity parameters have been correlated with theoretical entries obtained by different computer programs based on the neural network and fragmental methods.

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