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991.
Laura Barp Giorgia Purcaro Flavio A. Franchina Mariosimone Zoccali Danilo Sciarrone Peter Q. Tranchida Luigi Mondello 《Analytica chimica acta》2015
Phthalates are a group of synthetic compounds mainly used as plasticizers, which have been classified as endocrine-disrupting chemicals and potential human-cancer causing agents. They can be found in high amounts in foods, deriving mainly from plastic packaging. The analytical determination of these compounds is very challenging since they are ubiquitous. Therefore, minimization of sample manipulation is highly desirable. 相似文献
992.
993.
Mercedes Camalli Francesco Caruso Stanislav Chaloupka Luigi Chaloupka Luigi M. Venanzi 《Helvetica chimica acta》1988,71(4):703-711
The preparation of complexes {AgX(1c)} (X ? Cl, Br, I, NO3 and ClO4; 1c = 2,11-bis(diethylphosphinomethyl)benzo[c]phenanthrene) is reported. The 31P-NMR spectra of the above complexes were recorded and the 1J(107Ag, 31P) values are compared with the corresponding data for related complexes. The X-ray crystal structure of [Ag(1c)](ClO4) was determined. There are two crystallographically independent molecules in the unit cell each containing two-coordinate silver, the O-atoms of the perchlorate anions being outside bonding range from the central atom. The two molecules, however, show different bonding parameters: Thus for ‘molecule 1’ P(1)? Ag(1)? P(2) = 167.6(1)°, Ag(1)? P(1) = 2.389(3) and Ag(1)? P(2) = 2.393(3) Å, while for ‘molecule 2’ P(3)? Ag(2)? P(4) = 164.8(1)°, Ag(2)? P(3) = 2.377(3), and Ag(2)? P(4) = 2.378(3) Å. These differences are probably due to packing forces in the crystal lattice. 相似文献
994.
995.
Vincenzo Calo Luigi Lopez Giuseppe Marchese Giannangelo Pesce 《Tetrahedron letters》1979,20(40):3873-3874
Allylic ethers of benzothiazole react with copper(I) acetylides to afford 1,4-enynes under complete regio- and stereoselective control. 相似文献
996.
997.
Federica Barontini Valerio Cozzani Luigi Petarca 《Journal of Analytical and Applied Pyrolysis》2003,70(2):72-368
The influence of aluminum on the thermal stability of hexabromocyclododecane (HBCD) was investigated. HBCD pyrolysis was carried out using thermogravimetric analyzers and a laboratory scale reactor. The identification of decomposition products was based on FTIR and gas-chromatographic/mass-spectrometric techniques. The results obtained confirmed that the presence of aluminum caused a lower thermal stability of HBCD. However, the presence of aluminum also resulted in a significant increase of the char yield and caused the shift towards an exothermic decomposition process. The analysis of the decomposition products showed that the presence of aluminum triggers polycondensation reactions during HBCD thermal degradation. 相似文献
998.
Francesco Bellucci Maio Valentino Tullio Monetta Luigi Nicodemo Jose Kenny Luigi Nicolais Jovan Mijovic 《Journal of Polymer Science.Polymer Physics》1995,33(3):433-443
Dielectric measurements were utilized to follow the advancement of cure in a bifunctional and a tetrafunctional epoxy/amine formulation. In deferance to earlier dielectric studies of cure, complex impedance was measured and used to calculate ionic resistivity. By using complex impedance we were able to separate, according to their frequency dependence, the contributions to overall polarization from electrode blocking layers, mobile charge carriers, and dipole relaxations. At any stage of cure, there is a unique frequency at which ionic resistivity can be singularly measured. Our approach does not involve trial-and-error frequency search, it measures dielectric response in real time, and is conducive to the development of phenomenological models based on equivalent circuits. Values of ionic resistivity measured at different cure time and temperature were used to quantify the progress of cure. Excellent agreement was reported between the calculated values of normalized degree of cure obtained by dielectric and calorimetric measurements. It was suggested that apart from the extrinsic conductivity by ionic impurities, an intrinsic mechanism which involves the reactive molecules contributes to the overall ionic conductivity. © 1995 John Wiley & Sons, Inc. 相似文献
999.
1000.