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231.
You Na Lee 《Journal of Nuclear Science and Technology》2016,53(8):1178-1182
Emergency power systems in nuclear power plants are necessary for supplying power for safe operation during emergencies. Lithium-ion batteries can be used in power systems, but they have issues with material degradation under irradiation. To solve these problems, the development of an electrode with high stability under irradiation is needed. The electrochemical stability of Fe2O3-coated LiCoO2 (LCO) under irradiation was investigated. Fe2O3 is known to have a radiation shielding effect. The X-ray diffraction results for irradiated Fe2O3/LCO materials exhibited peaks of pristine LCO. In addition, Fe2O3 particles were observed to be well dispersed on LCO by scanning electron microscopy/energy dispersive X-ray spectroscopy. Electrochemical measurements revealed that the retention ratio of the discharge capacity for Fe2O3-coated/LCO was more stable than the capacity retention of non-coated LCO under irradiation. 相似文献
232.
Xudong An Te Zhu Mingpan Wan Yuanhui Li Qianqian Wang Peng Zhang Jinyang Liu Yamin Song Zhaokuan Zhang Baoyi Wang Xingzhong Cao 《International Journal of Hydrogen Energy》2021,46(24):13162-13170
The formation of mono-vacancy, vacancy clusters and hydrogen-vacancy complexes with 30 keV H ion-irradiated pure titanium at different doses and temperatures was measured using by Positron annihilation spectroscopy (PAS). Results show a large number of HmVn clusters and vacancy-like defects in the samples irradiated at for room temperature, and that the formation of HmVn (m > n) at the sample irradiated at a high dose inhibits the increase of the S parameter. At increased irradiation temperature, the shrinkage of vacancy clusters and the effective open volume of defects decrease the S parameters. The high-temperature irradiation results in decreased vacancy-type defect concentration, and some hydrogen atoms diffuse from the cascade region to the track region, forming a large number of hydrogen-vacancy complexes in the track region. The coincidence Doppler broadening spectroscopy, an element analysis method, used to detect hydrogen in the ion-irradiated pure titanium sample, and results show hydrogen-related peaks in the high-momentum region, which may be due to the information of positron annihilation in the covalent bond formed by the H and the Ti elements. The increased radiation dose and temperature contribute to the formation of the hydrogen vacancy-complex, and the positron annihilation in high-momentum regions easily obtain hydrogen-related information. 相似文献
233.
《Journal of Nuclear Science and Technology》2013,50(5):341-348
The NH3 consumption by electron beam irradiation has been studied in the moist NO-SO2-O2-N2 mixtures containing NH3. The [NH3] decreased linearly with increasing dose at various NH3 initial concentrations. The G(-NH3) increased with NH3 concentration up to about 500 ppm and was held almost constant G(-NH3)=5.8 at 750 ppm NH3) above it. The rate of the NH3 consumption was about 175 ppm/Mrad above 500 ppm NH3 The G(-NH3) increased with H20 and SO2 concentrations. On the contrary, the G(-NH3) decreased with increasing NO concentration and was hardly affected by the presence of 3–19.5% O2. The G(-NH3) became larger with decreasing temperature in the range of 80–150°C. An apparent activation energy of the NH3 consumption was ?3.82 kcal/mol. The NH3 is mainly consumed by the reactions of NH3 with HNO3 and H2SO4, leading to the formations of NH4NO3 and (NH4)2SO4 respectively 相似文献
234.
An equation relating the measured irradiance and the output power of a fluorescent lamp was derived by Keitz. The equation forms the basis for a new protocol that has been proposed for quantifying the total flux from an ultraviolet lamp. There has been confusion in the literature regarding the spatial distribution of flux from lamp emitters, which has led to emission models that are similar to the Keitz model but are incorrect. The Keitz equation is derived here from first principles in an effort to eliminate the confusion and present a correct method of calculating total flux. 相似文献
235.
Sterilization of implants and other clinical accessories is an integral part of any medical application. Although many materials are used as implants, polyethylene stands unique owing to its versatility. Carbon nanotubes are being used as a filler material to enhance the properties of polyethylene. However, the role of multi walled carbon nanotubes (MWCNTs) as an effective antioxidant and radical scavenger in resisting the deteriorating effects of sterilization is yet to be studied in detail. The present work is aimed to investigate the mechanical properties and oxidation stability of irradiated high density polyethylene (HDPE) reinforced by MWCNTs with various concentrations such as 0.25%, 0.50%, 0.75% and 1.00 wt.%. The composites were exposed to 60Co source in air and irradiated at different dosage level starting from 25 to 100 kGy and then shelf aged for a period of 120 days prior to investigation. The loss in toughness, Young’s modulus and ultimate strength at 100 kGy for 1 wt.% MWCNTs composite were found to be 21.5%, 20.3% and 19.2%, respectively compared to that of unirradiated composite. FTIR and ESR studies confirmed the antioxidant and radical scavenging potentialities of MWCNTs with increased concentration and irradiation dosage. It was found that by the addition of 1 wt.% MWCNTs into virgin HDPE, the oxidation index of the composite at 100 kGy was decreased by 56.2%. It is concluded that the addition of MWCNTs into polyethylene not only limits the loss of mechanical properties but also improves its post irradiation oxidative stability. 相似文献
236.
Pooja Sarker Sapan Kumar Sen M.N.H. Mia M.F. Pervez A.A. Mortuza Sazzad Hossain M.F. Mortuza M.H. Ali Salahuddin Nur Humayun Kabir M.A.M. Chowdhury 《Ceramics International》2021,47(3):3626-3633
This study reports the influences of gamma irradiation (GI) in the range of 20–100 kGy on CuO thin films via thermal spray pyrolysis technique on the glass substrates. The results demonstrate significant influences of GI on the crystallographic, microstructural and optical characteristics of CuO thin films. The obtained XRD results showed that the crystallinity of the films deteriorates by gradually decreasing crystallite size (from 59.13 to 46 nm) as applied gamma doses increases. However, the basic monoclinic crystal structure remains same. The dislocation density and lattice strain increased with the rise of GI absorbed dose due to the creation of defects. The values of number of crystallites per unit surface area increased as dose increased indicating the abundance of crystallization of nano CuO thin films. A UV–Vis–NIR spectrophotometer was utilized to determine the optical properties and obtained results indicated that the optical energy band gap (OBG) energies reduced from 2.00 to 1.72 eV as the doses increased from 0 to 100 kGy. No distinctions of the monoclinic phase of virgin CuO thin film have been perceived under applied absorbed doses, notwithstanding the slight deterioration of the crystallinity and narrowing the OBG. 相似文献
237.
Yingying Sun Yanshun Xu Pei Gao Wenshui Xia Qian Hua Qixing Jiang 《International Journal of Food Science & Technology》2021,56(1):224-232
To evaluate the effects of irradiation and thermal treatments on the quality characteristics of the vacuum-packaged low-salted fermented fish (Suanyu) during 90-day storage, thermal-treated group (TTG), irradiated-treated group (ITG) and non-treated group (CG) were prepared. The results showed that total viable counts reduced by 4.49 and 4.67 log CFU/g after thermal and irradiation treatments, respectively, and no coliforms and pseudomonas growth occurred during storage. Compared with CG, lower levels in L*, springiness, chewiness of TTG and higher levels in L*, b* and chewiness of ITG were detected after 90-day storage. Total biogenic amines content was significantly reduced in ITG compared with CG and TTG (P < 0.05). Both irradiation and thermal treatments have the potential to maintain quality of Suanyu during room storage. Compared with irradiation, thermal treatment could better stabilise the free amino acids and volatile compounds of Suanyu during room storage, but had some negative effects on texture quality. 相似文献
238.
239.
We present the first active visible blind ultraviolet (UV) photodetector based on zinc oxide (ZnO) nanostructured AlGaN/GaN high electron mobility transistors (HEMTs). The ZnO nanorods (NRs) are selectively grown on the gate area by using hydrothermal method. It is shown that ZnO nanorod (NR)-gated UV detectors exhibit much superior performance in terms of response speed and recovery time to those of seed-layer-gated detectors. It is also found that the best response speed (~10 and~190 ms) and responsivity (~1.1×105 A/W) were observed from detectors of the shortest gate length of 2 µm among our NR-gated devices of three different gate dimensions, and this responsivity is about one order higher than the best performance of ZnO NR-based UV detectors reported to date. 相似文献
240.
《International Journal of Hydrogen Energy》2019,44(10):4698-4706
Polyaniline is a typical conducting polymer with high migration electron rate, good stability, eco-friendly properties, and high absorption coefficients for visible light. In the present study, polyaniline decorated Pt@TiO2 for visible light-driven H2 generation is reported for the first time. The above-mentioned nanocomposite is prepared through a simple oxidative-polymerization and characterized by infrared spectroscopy, transmission electron microscopy, X–ray diffraction, thermogravimetric analysis, and ultraviolet–visible diffuse reflectance spectra. Polyaniline modification improves the absorption of the nanocomposite in visible light region via a photosensitization effect similar to dye–sensitization but does not influence the crystal structure and size of Pt@TiO2. The polyaniline modified Pt@TiO2 exhibits a remarkable visible light activity (61.8 μmol h−1 g−1) and good stability for H2 generation (with an average apparent quantum yield of 10.1%) with thioglycolic acid as an electron donor. This work provides new insights into using conducting polymers, including polyaniline, as a sensitizer to modify Pt@TiO2 for visible-light hydrogen generation. 相似文献