最新刊期
期 5 ， 2018
- 摘要：Cellulose pulp was used as raw material and a nano-cellulose dispersion was successfully prepared via electron beam radiation degradation, wet refining, and high-pressure homogenization treatment. The results showed that the parameters in the nano-cellulose preparation optimization process were as follows:the fiber dispersion concentration was 2%, refining frequency was 5 times, alkali concentration was 5%, and absorbed dose was 100 kGy. The diameter and length of the prepared nano-cellulose were approximately 60 nm and 1 μm, respectively.关键词：Electron beam radiation;Degradation;Nano-cellulose
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发布时间：2021-12-10 - 摘要：Radiation oxidation of polypropylene (PP) and PP with 2% crosslinking agent triallyl isocyanurate (TAIC) (J-PP) powders (the size of the powder particles was approximately 48 μm) were investigated under gamma-ray and electron beam irradiation in air at room temperature (25℃). Electron spin resonance (ESR), Fourier-transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG), and gel permeation chromatography (GPC) were used to characterize the free-radical concentration, chemical structure, thermal stability, and oxidation scission induced by gamma-ray or electron beam irradiation, and the effects of the absorbed dose and dose rate on the properties of PP were also studied. The results showed that peroxy radicals and oxidative products were formed upon irradiation for both PP and J-PP powders, and the addition of the crosslinking agent TAIC could not prevent the degradation of polypropylene. The melt flow index (MFI) and GPC results revealed that the average molecular weight of the irradiated PP and J-PP powders declined with the increasing absorbed doses.关键词：Gamma-rays;Electron beam;polypropylene powder;Oxidation scission
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发布时间：2021-12-10 - 摘要：Polyvinylidene difluoride (PVDF) microspheres functionalized with aminobenzo-15-crown-5 (PGB5) were prepared via pre-irradiation emulsion grafting polymerization of glycidyl methacrylate. The chemical structure and performance in lithium isotope separation of the PGB5 microspheres were characterized by Fourier-transform infrared (FT-IR) spectroscopy, elemental analysis, and scanning electron microscopy (SEM). The loading capacity of aminobenzo-15-crown-5 was ~1.2 mmol/g. The equilibrium adsorption time of PGB5 microspheres for Li+ in aqueous solutions was about 20 h. Moreover, Li+ is more easy to adsorb if the counter anion is softer. Under optimized condition, i.e., 25℃ and pH=7, the maximum adsorption capacity for Li+ reached 4.50 mg/g in a LiSCN solution, and the maximum isotope separation factor reached 1.05±0.02 in a CH3COOLi solution.关键词：Benzo-15-crown-5;Lithium isotope separation;Pre-irradiation emulsion grafting;Solid-liquid extraction
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发布时间：2021-12-10
RADIATION CHEMISTRY
- 摘要：A carbon fiber nanoelectrode (CFNE) was prepared using the flame-etching method. Scanning electron microscopy and cyclic voltammetry were used to characterize its diameter and the electrochemical properties, respectively. Differential pulse voltammetry was used to detect dopamine (DA) in vitro. A patch clamp in the voltage-clamp mode was used to monitor the release of DA from PC12 cells after stimulation with an elevated K+ solution, maintaining the voltage at 700 mV. The results showed that CFNE was successfully prepared with a diameter of ~100 nm, and excellent nonlinear diffusion behavior was observed on the nanoelectrode surface. Further, the nanoelectrode showed excellent response to DA with the limit of detection of 10 pmol/L. After PC12 cells were stimulated with the elevated K+ solution, the DA release process of PC12 cells at a single release site was monitored in real time.关键词：Carbon fiber nanoelectrode;Neuron-like cell;Single release site;Dopamine;Real-time monitoring
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发布时间：2021-12-10 - 摘要：Fifty-seven female Kunming mice aged 2 months received full-body irradiation once with 137Cs γ-rays at doses of 0, 4, 6, 8, and 10 Gy. The survival rate and body weight were then observed for 35 d. The animals' behaviors were analyzed using open-field and novelty location tests 35 d post irradiation. The expression of the neuronal marker NeuN in hippocampus was determined using western blot. The results showed that the mice in the 4 Gy group exhibited a higher survival rate and superior general status than did those in the other groups. Compared with the control group, the mice in the 4 and 6 Gy groups had a lower discrimination index in the novelty location test (36.04%±4.39% vs. 11.45%±6.34% vs. -1.40%±9.27%, respectively, p < 0.05), and had a remarkably lower level of NeuN expression in hippocampus (1.000±0.045 vs. 0.795±0.052 vs. 0.332±0.024, respectively, p < 0.05). Meanwhile, the mice in the 6 Gy group exhibited more serious cognitive dysfunction and neuronal death than did those in the 4 Gy group. The mice in the 8 and 10 Gy groups showed a higher death rate than those in the 4 and 6 Gy groups. However, no significant difference in survival rate was found between the mice in the 4 and 6 Gy groups. Our results suggest that 137Cs γ-ray irradiation can induce cognitive dysfunction and neuronal death in a dose-dependent manner at a dose of < 6 Gy.关键词：Ionizing radiation;γ-rays;Cognitive function;Neuron
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发布时间：2021-12-10
RADIOBIOLOGY AND RADIOMEDICINE
- 摘要：In recent years, with the increase of nuclear accidents and the possible need for future war, countries are paying increased attention to the harm caused by radiation injury, and research on drugs that can offer radiation protection is ongoing. Anti-radiation drugs can reduce cell or body damage caused by ionizing radiation and play an important role in radiation protection system. Genistein, a natural active component, has become a hotspot in the research of anti-radiation drugs because of its strong anti-radioactivity and fewer toxic side effects. The research on military radiation injury in the United States has reached the clinical trial stage. In this paper, the recent advances with respect to radioprotective activities of genistein are reviewed.关键词：Radiation injuries;Genistein;Radiation-protective agents;Review
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发布时间：2021-12-10
REVIEW
- 摘要：Common white wines, Daqu (base liquor, new liquor, and aged liquor) and Xiaoqu (malt liquor and buckwheat rice liquor) were irradiated by a 10 MeV electron-beam at absorbed doses of 0 (control), 2, 4, 6, and 8 kGy. The volatile aroma compounds in the liquor were analyzed using gas chromatography and mass spectrometry (GC/MS), and the liquor taste was evaluated through quantitative sensory evaluation. The results showed that the concentrations of alcohols, esters, and alkanes in Daqu liquor changed little after irradiation; the concentrations of acids, and aldehydes increased clearly, especially for new liquor; the ketones in the new liquor basically disappeared after irradiation (≥ 4 Gy) and almost no content was detected in the aged liquor. The aged flavor of Daqu liquor increased after irradiation and was dose-dependent. However, the concentration of volatile components in Xiaoqu liquor showed an irregular change with the absorbed dose, and the overall flavor of Xiaoqu liquor deteriorated. These results indicate that electron-beam irradiation may age Daqu liquor, and the effects of aging Xiaoqu liquor need to be studied further.关键词：Daqu;Xiaoqu;Liquor;Radiation;Aging
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发布时间：2021-12-10 - 摘要：The cross-linking effect of radiation on acrylic paint was investigated in order to block the emission of radon from walls and to reduce its harmful influence on the human body. As a result, a new method is proposed for the development of an anti-radon coating. The investigated coating was irradiated with gamma-rays, and the absorbed dose was in the range of 1 to 10 kGy in increments of 1 kGy. Subsequently, the cross-linking effect of the different absorbed doses on the coating was examined. The results indicated that when the absorbed dose was less than 2 kGy, the cross-linking effect of the coating increased with the absorbed dose, and the corresponding radon prevention efficiency also gradually increased. An absorbed dose of 2 kGy resulted in a maximum value of 67.3% for the flood prevention efficiency. In the case when the absorbed dose was more than 2 kGy, the cross-linking effect gradually decreased with an increase in the absorbed dose, and the anti-radon effect of the paint progressively deteriorated.关键词：Irradiation;Cross-linked;Anti-radon;Coating
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发布时间：2021-12-10
RADIATION TECHNOLOGY APPLICATION
- 摘要：The paramagnetic resonance spectroscopy technique was used to detect the electron paramagnetic resonance (EPR) signal intensity and Q-factor at different positions in the resonant cavity of a glass sample, as well as with increasing glass mass. The results showed that the signal intensity at various distances from the center of the resonant cavity follows a normal distribution:at the center of the resonant cavity, the signal intensity was the highest, while the farther away from the center, the lower the signal sensitivity and the smaller the signal intensity. Serious signal distortion started at ≥ 4 mm or ≤ -4 mm from the center, and the signal intensity and Q-factor at negative positions were higher than those at the positive symmetry positions. The signal intensity increased with increase in the glass mass, reaching saturation at approximately 100 mg. The Q-factor decreased with increasing mass and changed with different positions and directions. Therefore, taking into account the maximization of signal intensity and signal-to-noise ratio, and minimization of mass and position effects, the optimal detection position is at the resonant cavity center (±2 mm), with the best sample mass ≤ 100 mg.关键词：Electron paramagnetic resonance (EPR);Signal-to-noise ratio;Signal strength;Cavity;Q-factor
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发布时间：2021-12-10
RADIATION PHYSICS
- 摘要：During a nuclear emergency response, detailed spatiotemporal distribution visualization helps to make quick and effective scientific decisions to analyze large-scale nuclide diffusion data. Thus, a method based on scientific visualization is developed in this study. An optimized index management method, based on a traditional Octree structure, is adopted to establish spatial indexes for diffusion data and extract horizontal spatiotemporal slices according to the operation intervention levels. Considering the Fukushima nuclear accident in Japan as an example, large-scale radionuclide diffusion data are visualized in layers, so that the spatial distribution of radionuclides at different heights can be visualized. The results show that this method can provide technical support and facilitate decision-making during nuclear emergency response incidents.关键词：Large-scale data processing;Nuclide diffusion;Spatiotemporal visualization;Nuclear accident emergency
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发布时间：2021-12-10
RADIATION INTERDISCIPLINARY RESEARCH
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