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991.
The arsenic response obtained by arsine generation is decreased by the presence of the filter digest; a period of 25 min after mixing is needed before added arsenic gives a constant response. 相似文献
992.
Summary Glass transition measurements of nylon-6/lithium halides mixtures have been carried out in wide range of frequency with the aid of different experimental techniques.The results show an increase of the glass transition temperature when the salt is present and prove the larger effectiveness of lithium chloride with respect of lithium bromide.This effect, in line with the large reduction of the specific volume caused by the salt, is due to the formation of a pseudo-cross-linking between lithium ions and the carbonyl-oxygen groups of the polyamide. 相似文献
993.
C. Bacci V. Bidoli G. Penso B. Stella R. Baldini-Celio G. Capon R. Del Fabbro G. De Zorzi E. Iarocci G. La Rosa C. Mencuccini G.P. Murtas M. Spinetti V. Valente 《Physics letters. [Part B]》1976,64(3):356-358
A search for possible new resonances produced in e+e- annihilation at Adone has been performed in the mass region 2520–2990 MeV. No evidence has been found for new resonances. We obtain an upper limit on the energy integrated resonant cross section of about 6% of the J/ψ (3100) corresponding value. 相似文献
994.
995.
R. Tamisier B. Ramstein P. Avignon L.H. Rosier G. La Rana F. Guilbault C. Lebrun C. Jeanperrin 《Nuclear Physics A》1982,385(3):430-448
The 74Ge(p, p') inelastic scattering has been studied at 22 MeV with an overall resolution of 10 keV using a tandem Van de Graaff and a split-pole magnetic spectrometer. Angular distributions have been obtained for about 40 levels in 74Ge and comparisons with DWBA and CCBA calculations have allowed spin and parity assignments. The presence of an important collective component in the wave functions of many levels is required in order to explain the data. Possible unnatural-parity levels are populated. 相似文献
996.
997.
Du W Syvitski R Dewilde S Moens L La Mar GN 《Journal of the American Chemical Society》2003,125(27):8080-8081
The solution 1H NMR spectrum of oxidized (met) mouse neuroglobin, metNgb, demonstrates that it is low-spin and hexacoordinate with strong spectral similarities to ferricytochrome b5. The axial ligands are identified as His(F8) and His(E7), with the latter exhibiting an unstrained Fe-His bond. The presence of two sets of resonances is shown to arise from equilibrium heme orientational isomers ( approximately 2:1). The ligation of cyanide is shown to be extraordinarily slow with a factor approximately 2 difference in rate for the two heme orientations. Not only is Ngb the first mamalian globin with equilibrium heme disorder, but the disorder also has additional functional consequences. 相似文献
998.
A series of aluminosilicates with an Al/Si ratio ranging from 0 to ∞ (0 for pure silica and ∞ for pure alumina) was prepared by sol-gel process and characterized by surface and structure techniques. Aluminum trisecbutoxide and tetramethylorthosilicate were used as precursors for the sol-gel synthesis. The acidic properties of the oxides were studied by determination of the zero point charges, through mass titration method, and, for selected samples, by FT-IR spectroscopy of adsorbed pyridine used as a probe for both Brønsted and Lewis acidity. A dependence of the acidity on the Al/Si atomic ratio was found. According to the X-ray diffraction patterns, all the oxides have an amorphous structure except pure alumina exhibiting a γ-alumina pattern. The surface areas of the mixed oxides increase with increasing amount of alumina and are higher as compared to the individual oxides. The surface elemental distribution and electronic properties were investigated by X-ray photoelectron spectroscopy. According to the results, good agreement between the surface Al/Si atomic ratio and the analytical ratio is obtained. 相似文献
999.
Given a continuous interval map f we obtain a characterization of those closed nowhere dense and strongly invariant sets by f that can be -limit sets for such a map. 相似文献
1000.
Ding Y.-F. La Y.-T. Li W.-D. Yao G.-X. Wang L. Dong W.-K. 《Russian Journal of General Chemistry》2022,91(1):S89-S97
Russian Journal of General Chemistry - Two new trinuclear Ni(II) complexes, [{Ni(L)(DMF)(μ-OAc)}2Ni] (1) and [{Ni(L)(EtOH)(μ-OAc)}2Ni]·2CH2Cl2 (2), have been successfully synthesized... 相似文献