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971.
Renan S. Ferrarini João V. Comasseto Alcindo A. Dos Santos 《Tetrahedron: Asymmetry》2009,20(17):2043-2047
The components of the pheromone blend of Mayetiola destructor, Drosophila mulleri, and Contarinia pisi were synthesized in high enantiomeric excess (99% ee) from a common enantiopure dianion prepared from an enantiopure hydroxytelluride. 相似文献
972.
Roberta C. Salles Valdemar Lacerda Jr Adilson Beatriz Felicia M. Ito Reginaldo B. dos Santos Sandro J. Greco Eustáquio V. R. de Castro Dênis P. de Lima 《Magnetic resonance in chemistry : MRC》2010,48(5):409-415
Bioactive cage‐like polycyclic compounds have attracted the attention of several research groups because of their unique appearance and their biological activities. Their structures were established on the basis of 1H NMR and 13C NMR spectroscopic data. The 1H and 13C signal assignments and most homonuclear hydrogen coupling constants were assigned by use of techniques such as 1D 1H and 13C NMR and 2D gCOSY, non‐edited gHSQC and gHMBC. The gNOESY experiments proved the endo‐stereochemistry. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
973.
974.
975.
Márcia R. S. Silva L. E. B. Soledade S. J. G. Lima E. Longo A. G. Souza Iêda M. G. Santos 《Journal of Thermal Analysis and Calorimetry》2007,87(3):731-735
The present work investigates
the influence of milling and calcination atmosphere on the thermal decomposition
of SrTiO3 powder precursors. Both pure and neodymium-modified SrTiO3 samples
were studied. Milling did not significantly influence numerical mass loss
value, but reduced the number of decomposition steps, modifying the profiles
of the TG and DTA curves. On the other hand, milling increases the amount
of energy liberated by the system upon combustion of organic matter. It was
also observed that the milling process, associated to the calcination in an
oxygen atmosphere, considerably decreases the amount of organic matter and
increases the final mass loss temperature. 相似文献
976.
V.M. Prida V. Vega J.L. Sánchez Llamazares J.D. Santos J.J. Suñol 《Journal of magnetism and magnetic materials》2009,321(7):790-792
Fe-30%Pd alloys in ribbon and nanowire geometry have been prepared. Ribbon samples were produced by the melt-spinning technique in the Ar environment. FePd nanowires, having about 35 nm in diameter, 105 nm inter-nanowires distance and around 4 μm in length, were synthesized into nanoporous anodic alumina membranes as templates. Energy dispersive X-ray microanalysis of ribbons shows an average atomic composition of Fe (73.2%) and Pd (26.8%). The X-ray diffraction at RT analysis was performed on both surfaces, free and wheel side, of the melt-spun ribbon. It shows the coexistence of two phases: fct and bct FePd, but with differences between both surfaces consisting the existence of Fe oxides (Fe2O3 and Fe3O4) and a textured 200 reflection in the free side. Heating and cooling thermomagnetic curves exhibit a reversible behaviour from RT to 720 K, but around 770 K a clear irreversible transformation takes place. 相似文献
977.
R.A. Silva M.J.L. Santos A.W. Rinaldi A.J.G. Zarbin M.M. Oliveira I.A. Santos L.F. Ctica A.A. Coellho A.F. Rubira E.M. Girotto 《Journal of solid state chemistry》2007,180(12):3545-3550
Magnetite and poly(thiophene) composites have been produced by in situ monomer oxidation. Fourier transform infrared (FTIR) and X-ray diffraction (XRD) confirmed the presence of Fe3O4 as particle agglomerates ranging from 15 to ca. 54 nm in size. Transmission electron micrographs (TEMs) revealed a face-to-face structure in both the pure magnetite and the nanocomposite. Typical superparamagnetic (ferrimagnetic) curves have been observed, whereas the relatively weak magnetic field employed in measurement, 200 Oe, was sufficient to split the curves completely. Zero field cooling (ZFC) and field cooling (FC) curves coincide only above room temperature, indicating that the characteristic blocking temperature (TB) for superparamagnetic particles in this assembly is above room temperature. 相似文献
978.
979.
Ana C.F. Ribeiro Victor M.M. Lobo Hugh D. Burrows Artur J.M. Valente Ana M. Amado Abílio J.F.N. Sobral Ana S.N. Teles Cecília I.A.V. Santos Miguel A. Esteso 《Journal of Molecular Liquids》2008,140(1-3):73-77
Numerical values for the mean distance of closest approach of ions, “a”, for lithium salts in aqueous solutions are presented and discussed. These values were obtained from both experimental activity and diffusion coefficients, and estimated by using different theoretical approaches. 相似文献
980.
Csar Jorgino Julio de Santana Marcos Aurlio de Oliveira Marcelo E. Santos Alexandre G. de Miranda Alexandre A. Cerqueira Santos Alexandre M. Costa Santoro Marcelo Matos de Andrade Milton H. Guerra 《Chromatographia》2009,69(3-4):357-360
The Macrotyloma axillare Bowman-Birk inhibitors from seeds and germinated seeds (120 h) were purified by an alternative methodology and revealed the presence of different contents of inhibitors for each treatment. Mass analyses of inhibitors, from seeds and germinated seeds, showed masses of about 7 and 8 kDa. The 120 h-germinated seed fractions presented higher activity isoforms than seeds without treatment.
相似文献