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101.
H.M. Mahmudov M.K. Ismayilova S.A. Hasanova S.M. Aliyev G.E. Isayeva O.E. Akberov 《辐射效应与固体损伤》2016,171(7-8):630-635
The aim of this study was to investigate the regularities of molecular hydrogen formation from water dispersing Al2O3 nanoparticles irradiated with gamma ray. It was established that formed molecular hydrogen’s yield changed depending on the size of the catalyst, so that yield of molecular hydrogen formed on the surface with small size is 1.4–1.6 times greater than the one with big size. Equal distribution of nanocatalyst in water medium and much more adsorption of water molecule on the catalyst surface result in more efficient radiolysis process. 相似文献
102.
N. Shanta Singh R.S. Ningthoujam S. Dorendrajit Singh B. Viswanadh N. Manoj R.K. Vatsa 《Journal of luminescence》2010,130(12):2452-2459
Highly crystalline spherical nanoparticles of MVO4:Tm3+ (M=Gd, Y) having a size of 20–45 nm were prepared using ethylene glycol as both capping agent and reaction medium. X-ray diffraction study shows linear decrease in the unit cell volume with an increase in Tm3+ concentrations in MVO4 (M=Gd, Y; Tm3+=0, 2, 5, 7, 10, 15, 20, 40, 60, 80 and 100 at%), indicative of quantitative substitution of Gd3+/Y3+ lattice sites by Tm3+ ions in MVO4. Blue light emission at 475 nm is observed after excitation at 310 nm due to energy transfer from VO43− absorption band to Tm3+. Emission intensity and average decay lifetime increase with an increase in heat treatment from 500 to 900 °C. This has been attributed to an extent of reduction in non-radiative process arising from surface. The emission intensity of Tm3+ in GdVO4 host is higher than that in YVO4 and thus the former host is better. Quantum yield increases with increase in heat-treatment temperature. This material will be the alternative blue light emitter. 相似文献
103.
The emission spectra of pure cellulose samples of various origins were monitored during several heating/cooling cycles. During heating the emission intensity decreased due to the greater probability for internal conversion at higher temperatures. Cooling resulted in an emission recovery that was nearly reversible over several heating/cooling cycles, provided that the final 0temperature was sufficiently low. The change in the relative emission yield with temperature showed two regimes, both with linear decreases but different slopes, suggesting different mechanisms for the internal conversion in these regions. Heating to temperatures higher than 160°C for filter papers and higher than 145°C for microcrystalline cellulose initiated reactions that caused changes in the emission spectra typical of thermal degradation. If the samples were heated beyond these threshold temperatures the emission recovery on cooling after the first heat treatment occurred to a much higher intensity level than that observed initially, indicating the formation of a multitude of new chromophores due to thermal reactions. Exposure of the samples to IR radiation caused a slow increase in the emission intensity for almost 600h. 相似文献
104.
105.
106.
A. Küçükönder 《Journal of Quantitative Spectroscopy & Radiative Transfer》2005,90(1):125-130
The K-shell fluorescence yields for potassium and calcium compounds were investigated using a Si(Li) X-ray detector system ( at ). The target samples were excited using gamma rays from an 241Am annular source of strength . Chemical effects on K-shell fluorescence yield for potassium and calcium were observed. The values were compared with theoretical values of pure potassium and calcium. 相似文献
107.
The synthesized macrocycle L is the novel fluorescent receptor having the switching ability by the external stimuli as well as having the recognizing ability of various metal ions. In particular, this macrocycle L shows the possibility of the selectivity of metal ions even in the same charge ions of a different metal, and the values of association constant (M−1) of that for metal ions are consistent with the tendency of increasing charge number of metal ion. In addition, the values of quantum yield (ΦF) of metal complexes of macrocycle L were ranged from 0.021 to 0.111 enough to recognize the metal ions in macrocycle L. We know from the fluorescent pH titration of macrocycle L by acid/base that the change of fluorescence intersects at about pH=5. 相似文献
108.
Merijs Meri R. Jablonskis I. Zicans J. Kalnins M. Bledzki A. K. 《Mechanics of Composite Materials》2004,40(3):247-252
Considering the wide applicability of polymeric composite materials, heterogeneous blends of poly(ethylene terephtalate) (PET) and polyethylenes of high and low densities (HDPE and LDPE, respectively) were investigated. Rheological (the flow-behavior index), mechanical (the yield strength and the Charpy impact strength), and morphological (crystallinity and the melting temperature) properties were detected for individual blend components and different blend compositions. A radiation treatment (-rays) was applied to improve certain characteristics of the heterogeneous blends. The results of this investigation show that the radiation modification can be successfully used to improve some physical properties of the PET-based blends and to choose individual blend components, optimum irradiation conditions, and desirable blend compositions, which allows producing materials with a predictable set of mechanical properties. 相似文献
109.
Neutron emission cross section for various elements from9Be to209Bi have been calculated using the hybrid model code ALICE-91 for proton induced reactions in the energy range 25 MeV to 105
Me V. An empirical expression relating neutron emission cross section to target mass number and incident proton energy has
been obtained. The simple expression reduces the computation time significantly. The trend in the variation of neutron emission
cross sections with respect to the target mass number and incident proton energy has been discussed within the framework of
the model used. 相似文献
110.
In (Deodhar, Geom. Dedicata, 36(1) (1990), 95–119), Deodhar proposes a combinatorial framework for determining the Kazhdan-Lusztig polynomials P
x
,
w
in the case where W is any Coxeter group. We explicitly describe the combinatorics in the case where
(the symmetric group on n letters) and the permutation w is 321-hexagon-avoiding. Our formula can be expressed in terms of a simple statistic on all subexpressions of any fixed reduced expression for w. As a consequence of our results on Kazhdan-Lusztig polynomials, we show that the Poincaré polynomial of the intersection cohomology of the Schubert variety corresponding to w is (1+q)
l(w)
if and only if w is 321-hexagon-avoiding. We also give a sufficient condition for the Schubert variety X
w
to have a small resolution. We conclude with a simple method for completely determining the singular locus of X
w
when w is 321-hexagon-avoiding. The results extend easily to those Weyl groups whose Coxeter graphs have no branch points (B
C
n
, F
4, G
2). 相似文献