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371.
The analytical behaviour of the relatively new pyrethroid insecticide tralomethrin has been evaluated by using gas chromatography (GC) with electron-capture and mass spectrometry (MS) detectors, and liquid chromatography (LC)-atmospheric pressure ionization mass spectrometry with electrospray interfacing. Under the GC conditions commonly used in pesticide residue analysis, it was found that tralomethrin is transformed into deltamethrin (in a reproducible way) in the injector port of the GC system. Results obtained in this work indicate that the GC multiresidue methodologies routinely applied in the analysis of pyrethroid pesticides in foods cannot distinguish between these two pesticides, and the chromatographic signal obtained at the retention time of deltamethrin/tralomethrin can be really quantified as either deltamethrin or tralomethrin, including when it is confirmed as deltamethrin by MS. Under the LC-MS conditions assessed in this work, deltamethrin and the two diasteroisomers of tralomethrin were well separated and identified. 相似文献
372.
A. A. Hassan N. K. Mohamed A. A. Aly A. -F. E. Mourad 《Monatshefte für Chemie / Chemical Monthly》1997,128(1):61-70
Summary The reaction of thiocarbohydrazides1a and thiocarbazones1b with tetracyanoethylene (TCNE) afforded the thiazol, thiadiazole, thiazine, and thiadiazepine derivatives4–7. 2-Dicyanomethyleneindane-1,3-dione (CNIND) reacted with1a,b to give aminoindenopyrazolopyridazinone (12) and phenyl-1,2,3,4-tetraazacyclopentafluorene (13). The indazole and oxathiadiazole derivatives17 and19 were formed during the reaction of1b with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDO). 6,7-Dichloro-5-phenylpyrazolophthalazinol (21) was obtained from the reaction of1b with 2,3,5,6-tetrachloro-1,4-benzoquinone (CHL-p). The oxidative cyclization of thiodicarbazones2a–d with the above acceptors afforded the thiadiazole and thiadiazine derivatives8 and10.
Eine neue Synthese von Heterocyclen aus Thiocarbohydraziden
Zusammenfassung Die Reaktion der Thiocarbohydrazide1a und der Thiocarbazone1b mit Tetracyanoethylen (TCNE) ergab die Thiazol-, Thiadiazol-, Thiazin- und Thiadiazepinderivate4–7. 2-Dicyanomethylenindan-1,3-dion (CNIND) liefert mit1a,b Aminoindenopyrazolopyridazinon (12) und Phenyl-1,2,3,4-tetraazacyclopentafluoren (13). Die Indazol- und Oxathiadiazolderivate17 und19 wurden durch Reaktion von1b mit 1,3-Dichlor-5,6-dicyano-1,4-benzochinon (DDQ) gebildet. 6,7-Dichlor-5-phenylpyrazolophthalazinol (21) wurde aus1b und 2,3,5,6-Tetrachlor-1,4-benzochinon (CHL-p) erhalten. Die oxidative Cyclisierung der Thiodicarbazone2a–d mit den obengenannten Akzeptoren ergab die Thiadiazol- und Thiadiazinderivate8 und10.相似文献
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376.
Mourad Bellassoued Masahiro Yamamoto 《Journal of Mathematical Analysis and Applications》2007,329(2):1240-1259
We consider an inverse problem of determining spatially varying density and two Lamé coefficients in a non-stationary isotropic elastic equation by a single measurement of data on the whole lateral boundary. We prove the Lipschitz stability provided that initial data are suitably chosen. The proof is based on a Carleman estimate which can be obtained by the decomposition of the Lamé system into the rotation and the divergence components. 相似文献
377.
Feel like writing a review for The Mathematical Intelligencer? You are welcome to submit an unsolicited review of a book of your choice; or, if you would welcome being assigned a book to review, please write us, telling us your expertise and your predilections. 相似文献
378.
Naofumi Honda Gen Nakamura Roland Potthast Mourad Sini 《Annali di Matematica Pura ed Applicata》2008,187(1):7-37
This paper addresses the inverse obstacle scattering problem. In the recent years several non-iterative methods have been
proposed to reconstruct obstacles (penetrable or impenetrable) from near or far field measurements. In the chronological order,
we cite among others the linear sampling method, the factorization method, the probe method and the singular sources method.
These methods use differently the measurements to detect the unknown obstacle and they require the use of many incident fields
(i.e. the full or a part of the far field map). More recently, two other approaches have been added. They are the no-response
test and the range test. Both of them use few incident fields to detect some informations about the scatterer. All the mentioned
methods are based on building functions depending on some parameter. These functions share the property that their behaviors
with respect to the parameter change drastically. The surface of the obstacle is located at most in the interface where these
functions become large. The goal of this work is to investigate the relation between some of the non-iterative reconstruction
schemes regarding the convergence issue. A given method is said to be convergent if it reconstructs a part or the entire obstacle
by using few or many incident fields respectively. For simplicity we consider the obstacle reconstruction problem from far
field data for the Helmholtz equation.
Gen Nakamura is partially supported by Grant-in-Aid for Scientific research (B)(2)(N.14340038) of Japan Society for Promotion
of Science.
Mourad Sini is supported by Japan Society for Promotion of Science. 相似文献
379.
380.
In this paper we prove the unique continuation property of the solution for the elastic transversely isotropic dynamical systems with smooth coefficients satisfying some conditions and apply it to extending the Dirichlet to Neumann map. The proof is based on the localized Fourier-Gauss transformation and Carleman type estimate. 相似文献