Rapid technological advancement has multiplied people’s exposure to ionizing radiations greatly. Widespread applications of radiation in different fields (such as agriculture, radiation therapy and scientific research fields) require that humans be protected against unnecessary exposure. In this study, mass attenuation coefficient (μm), half-value layer, mean-free path, effective atomic number (Zeff) and exposure buildup factor have been calculated for xBaO–20ZnO–(80???x)B2O3 (x?=?5, 10, 15, 20 and 25?mol%) glass systems. The mass attenuation coefficients of the selected glasses were calculated using simulation method of MCNP5 code. The simulation results have been compared with the experimental data and Xcom at the energies 223.02, 252.98, 287.28, 340.83, 398.97, 481.59, 562.68 and 662.00?keV. The agreement amounts of the mass attenuation coefficient values are from 0.2% to 2.8% and from 0.2% to 6.98% for MCNP5 and Xcom relative to experimental results, while the Monte Carlo program values are higher than that obtained by experimental data, using Xcom and MCNP5 code. The glass sample having the highest value of BaO content show high radiation shielding properties. It indicates that the MCNP5 code can be used for estimation of radiation interaction parameters where experimental results are not available. 相似文献
Chiral Schiff bases were obtained at high yields via a novel technique. Aryl aldehydes and chiral α‐amino acids were treated (1) in the presence of H3PO4 in ethanol at 80°C for 24 h, and (2) in the presence of K2CO3 under ultrasonic conditions in an aqueous ethanol medium within 5 min with yields reaching up to 96%. The results showed that the presented methodology under ultrasonic conditions was effective, practical, and eco‐friendly compared to that using an acidic medium. The corresponding asymmetric Schiff bases were synthesized for the first time, and were characterized by 1H and 13C nuclear magnetic resonance and infrared spectroscopy and high‐resolution mass spectrometry. 相似文献
The FT-IR, FT-Raman and FT-NMR spectra of the compound 4-(4-Chlorophenyl)-1H-imidazole (4-ClPI) was recorded and analyzed. Density functional method has been used to compute optimized geometry, vibrational wavenumbers and NMR spectra of the 4-ClPI. Only one tautomeric form was found most stable by using B3LYP functional with the 6?C311++G(d,p) as basis sets. The detailed interpretation of the vibrational spectra was carried out with the aid of total energy distribution (TED) following the scaled quantum mechanical force field methodology. 相似文献
Single crystals of ergosterol were investigated by Electron Paramagnetic Resonance (EPR) technique, with γ irradiation of the crystals at different orientations in the magnetic field between temperatures of 120 and 380 K, and the spectra were found to be slightly dependent on temperature. Because of the importance of ergosterol it is important to determine the irradiation effects on this molecule.Taking into consideration the chemical structure and the experimental spectra of the irradiated single crystal ergosterol, we found that two paramagnetic species which were labeled as radical A, CH2αHβ, and radical B, CHαHβHγHσ, were produced in the host crystal. The EPR parameters; spectroscopic splitting factor, g, and hyperfine coupling constant, a, were determined for each radical. 相似文献
Summary: Defined films of luminescent ruthenium(II ) polypyridyl‐poly(methyl methacrylate) (PMMA) and iridium(III ) polypyridyl‐polystyrene (PS) copolymers could be prepared by ink‐jet printing. The copolymers were deposited on photoresist‐patterned glass substrates. Films as thin as 120 nm could be printed with a roughness of 1 to 2%. In addition, the film thickness could be varied in a controlled way through the number of droplets deposited per unit area. The topography of the ink‐jet printed films was analyzed utilizing an optical profilometer. The absorbance and emission spectra were measured using fast parallel UV‐vis and fluorescence plate reader.
Photo of the solutions of luminescent ruthenium (left) and iridium (right) containing polymers in a glass microtiter plate (top). The subsequently prepared films using ink‐jet dispensing techniques are shown below. 相似文献
Encapsulation with PLGA of I3C and radioiodination have been performed. Anticancerogenic effects of I3C and I3C-PLGA have been investigated utilizing in vitro methods on breast adenocarcinoma epithelial (MCF7), colon adenocarcinoma epithelial (Caco2), prostate carcinoma epithelial (PC3) cells. Characterization of I3C-PLGA have been performed with DLS method and SEM analysis. I3C and I3C-PLGA compounds have been radiolabeled in high yields with 131I which is widely used for diagnosis and treatment in Nuclear Medicine. All experimental results demonstrated that radioiodinated compounds are promising in order to be used in Nuclear Medicine as well as present study contributed previously reported studies. 相似文献
Numerical solution of the Korteweg-de Vries equation is obtained by using the meshless method based on the collocation with radial basis functions. Five standard radial basis functions are used in the method of the collocation. The results are compared for the numerical experiments of the propagation of solitons, interaction of two solitary waves and breakdown of initial conditions into a train of solitons. 相似文献