最新刊期
卷 38 ， 期 3 ， 2020
- “硅橡胶辐射老化研究进展，总结了影响因素和表征方法，为预测服役寿命提供参考。”摘要：Silicone rubber are widely used in engineering for their excellent properties. When exposed to high-energy rays or particles, such as existing in aerospace and nuclear power plant applications, silicones would age. The irradiation-induced crosslinking and radiolysis lead to decreasing of material properties and thus influencing the service lifetime. Many factors affect the aging behaviors and make it hardly to predict. This article reviews the recent research progresses in this field and summarizes the effects of absorbed dose, dose rate, environment factors, and additives on radiation aging of materials. In addition, the characterization, simulation and modeling of irradiation-induced aging are also discussed. The thorough survey of the current literatures offers useful guidance to predict lifetime of the silicones.关键词：Silicone rubber;Irradiation;Aging;Review90|139|2更新时间：2025-02-28
REVIEW
- “最新研究发现，六方氮化硼/环氧树脂复合材料在核工业领域具有良好应用前景，其结构和性能在γ射线辐照后表现出稳定性。”摘要：Epoxy resin and its composites are widely utilized in the nuclear industry. In this work, epoxy composites were prepared by blending hexagonal boron nitride (h-BN) powder with tetrahydrophthalic acid diglycidyl ester, methyltetrahydrophthalic anhydride (curing agent), and 2,4,6-tris (dimethylaminomethyl) phenol (catalyst), followed by a thermal-curing process. The structure and properties (such as thermal stability, mechanical properties, and thermal conductivity) of the prepared h-BN/epoxy (h-BN/EP) composites were investigated before and after irradiation using 60Co γ-ray under an air or nitrogen atmosphere at a certain absorbed dose rate (60 Gy/min). The results showed that h-BN powder had good structural stability under γ-ray radiation at absorbed doses up to 380 kGy. However, the glass transition and initial thermal decomposition temperatures of the h-BN/EP composites were significantly lower than those of the pure EP matrix after γ-ray radiation. The effect of γ-ray radiation on the mechanical properties of h-BN/EP composites depends on both the h-BN content and the absorbed dose. For the composite with a low h-BN content (mass fraction<0.52%), the tensile strength decreased remarkably even after the composite was irradiated by γ-ray at a low absorbed dose (≤180 kGy). In contrast, for the composite with a higher h-BN content (mass fraction≥0.52%), the tensile strength increased significantly after the γ-ray radiation at the same absorbed dose. When the absorbed dose was 1 000 kGy, the tensile strengths of the irradiated pure EP and all irradiated h-BN/EP composites were the same, i.e., they had no relationship with the h-BN content. These results indicate that the thermal conductivity of the h-BN/EP composites will be greatly improved after γ-ray radiation at the absorbed dose of 180 kGy.关键词：Hexagonal boron nitride;Epoxy resin;γ-ray radiation;Thermal stability;Mechanical property;Thermal conductivity68|80|6更新时间：2025-02-28
- “辐射聚合工艺制备医用吸水树脂，优化合成条件，提高溶胀性能，为医疗领域提供高性能吸水材料。”摘要：The concept of radiation synthesis, its advantages and disadvantages compared with traditional polymer synthesis, the water absorption mechanism and swelling properties of super-absorbent resin (SAR) were introduced. There were many synthesis conditions that needed to be controlled, such as neutralization degree, absorption dose, and crosslinker dosage. Their influences on the swelling properties of poly(acrylic acid), super water-absorbent for medical use, were discussed in detail. In order to maximize the swelling properties, an electron beam radiation synthesis of high-performance, water-absorbent resin was designed. The uniform mixture was added into the atomization equipment, where mist droplets were polymerized through the ray curtain of the electron beam, to create gel particles. Surface crosslinking and sieving were subsequently carried out to form the water-absorbent resin. The effects of the absorption dose, the raw material, and dosage of the polymerization reaction on the swelling performance of SAR were studied. Absorbent resin product (2 g) was added into 50 mL of 0.9% NaCl solution and stirred at the speed of 600 r/min for 20 s; the time from the beginning of adding absorbent resin to the disappearance of the vortex was recorded as the absorption time. Regardless of the different polymerizing monomers, co-monomers, cross-linking agents, additives and surface cross-linking agents selected, the results showed that when the neutralization degree was around 65%~80% and the absorption dose was around 1~5 kGy, the absorption ratio of 0.9% NaCl solution to the absorbent resin product was about 70 g/g.关键词：Radiation synthesis;Water absorbent resin;Poly(acrylic acid);Swelling property36|54|0更新时间：2025-02-28
- “在提高重金属中毒治愈率领域，研究人员开发了基于辐射接枝基底的宏尺寸金属有机框架UiO-66-S膜，实现了对汞离子的高效选择性清除。”摘要：To develop efficient adsorption materials to improve the cure rate of heavy metal poisoning, we designed and prepared large size metal-organic framework (MOF) UiO-66-S films based on irradiation-grafting pretreated substrate, and investigated the selectivity of these films with multi-heavy metal ions in artificial plasma. The grafting density of maleic anhydride on a substrate was quantitatively measured by chemical titration and the effects of the radiation parameters on the grafting density were studied. The grafting density could be tuned from 0.10 to 75.80 nmol/cm2 by changing the radiation parameters. The investigation of surface wettability and mechanical property proved that the irradiation-grafting process changed the surface wettability of maleic anhydride grafting substrate but did not affect its mechanical property. We prepared UiO-66-S films by in-situ growth and post-synthesis modification on the substrate with the grafting density of 14.94 nmol/cm2 and characterized the film by attenuated total reflection flourier transformed infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscope, which showed how the nanothickness continuous MOF film was obtained. The UiO-66-S films exhibited high selectivity to mercury ions in the artificial plasma with multi-ions co-existing; the removal ratio reached more than 50%. The adsorption process followed the pseudo-second-order kinetic equation. Moreover, the mercury ion-removal rate of the UiO-66-S films in the artificial plasma was faster than that in pure water.关键词：Gamma-ray;Grafting density;Metal-organic framework;Artificial plasma;Mercury removal32|40|1更新时间：2025-02-28
RADIATION CHEMISTRY
- “在乳腺癌放疗领域，研究者对比了不同厚度Bolus对剂量学的影响，发现小空腔Bolus能减少靶区内冷热点，降低危及器官受量，更接近理想计划方案。”摘要：To improve bolus reliability, we compared three different cavity sizes generated by different bolus thicknesses in patients by introducing intensity-modulated radiation therapy (IMRT) after radical mastectomy and analyzed the differences in dosimetry. Three IMRT plans—1, 2, and 3—were designed for cavity sizes greater than 10 mm, greater than 5 mm and less than 10 mm, and less than 2 mm, respectively. All three plans were compared to Plan 4 (bolus clinging to the skin ), which was conventionally used as a standard benchmark case. The present study analyzed the dose-volume histogram (DVH) and three-dimensional dose distribution profiles. The differences in dose distributions between the target area and the organ at risk were evaluated by statistical analysis on statistical package of social sciences (SPSS). The dose parameters of all the four plans satisfied the prescription dose requirements and no statistically significant differences were observed (p<0.05). However, the dose distribution map showed that the target areas in the cavities had high concentration areas and cold areas nearby the skin for both Plans 1 and 2. The DVH results showed reduced mean dose (Dmean) to the esophagus and trachea, percent volume received by the affected lung (V30 ≥30 Gy), and percent volume received of the auxiliary structure ring (V40 ≥40 Gy and V45 ≥45 Gy) for Plans 3 and 4. The differences were statistically significant (p<0.05). Comparisons showed that Plan 3 reduced hot and cold spots around the target area, therefore reducing the risk of organ damage and indicating that it was the best plan in the present study. Plan 3 used a superposition method from 2 mm to 3 mm, which reduced the cavity size to less than 2 mm. It satisfies the compensation function of the bolus and avoids dosimetry error caused by the physical characteristics of the bolus, thus improving treatment quality.关键词：Bolus;Air containing space;Breast cancer;Intensity-modulated radiation therapy (IMRT);Dosimetry42|37|1更新时间：2025-02-28
- “最新研究发现，Pig-a和Gadd45α基因表达量变化可作为电离辐射生物剂量计应用，为辐射遗传损伤检测提供新方法。”摘要：This study aimed to improve the ability to detect the effects of radiation-associated genetic damage and establish a rapid and simple method for estimating biological dose. Radiation-sensitive genes were selected as biodosimeters from Pig-a, Gadd45α, and Hprt, based on their mRNA expression level changes. RT-qPCR was used to assay the relative expression level of the target genes in peripheral blood samples of healthy non-radiation (control group) and radiation workers (exposed group) and their relative expression level average, fluctuation range and variation coefficient of the background expression were counted. Peripheral blood samples of healthy adults were irradiated with different X-ray doses of 0 Gy, 0.10 Gy, 0.25 Gy, 0.50 Gy, 1.00 Gy, 2.00 Gy, and 5.00 Gy, respectively. 6 h later, the relative expression of the target genes was examined using RT-qPCR and the binomial regression curve analysis was performed to analyze the quantitative effect relationship. The results showed that Pig-a and Gadd45α expressions had small background level differences in the control group; Hprt had large background level differences and its variation coefficients were greater than 20%. The Hprt expression level in the control group was higher than that in the exposed group; Gadd45α and Pig-a expressions in the control group were lower than that in the exposed group (p<0.05). There was a dose-effect relationship between the Gadd45α and Pig-a expression levels and irradiation doses, indicating that the Pig-a and Gadd45α expression level changes could be used as potential biodosimeters.关键词：Radiation-sensitive gene;Biodosimeter;Gadd45α;Hprt;Pig-a33|27|0更新时间：2025-02-28
RADIOBIOLOGY AND RADIOMEDICINE
- “在提高60Coγ放射源辐照加工能力及灭菌效果研究中，专家分析了不同堆码厚度和辐照箱结构对食品辐照吸收剂量及其不均匀度的影响，为降低食品最低吸收剂量、提高γ射线能量利用率和辐照生产效率提供解决方案。”摘要：This study aims at improving the irradiation processing capability of the 60Co γ-radiation source and ensuring the quality of irradiated food. Thus, different stacking thicknesses and irradiation box structures were selected as process parameters, and the absorbed dose and unevenness of irradiated foods with different densities were measured and analyzed. The results showed that the spatial dose field distribution was symmetric with the center point of the source plate, symmetrically distributed above and below the center, and that the absorbed dose at the center was the highest. With increasing distance from the center, the absorbed dose decreased, and unevenness was observed. The greater the stacking thicknesses of products with the same density, the higher was the unevenness. There was no obvious effect of stacking thickness on low-density products. Combined with the dose distribution of the empty field, when the unevenness was greater than 1.4, the main contradiction was transformed into the influence of stacking thickness, mainly because of the inhomogeneity of the outer and central surfaces. At this time, in order to increase the utilization rate of γ-rays, the minimum dose and loading amount should be determined for the product with a density of less than 0.36 g/cm3, consider thinning instead of tiling for the product with a density of more than 0.36 g/cm3. For products with a density of 0.3 g/cm3, the spatial distribution of the irradiation field at a height of 5 cm from the bottom of the irradiation box was better than that of the punch. In addition, the γ-ray utilization of the irradiation box height and punch increased by 8.26% and 8.30%, respectively, compared with those for the original irradiation box. Therefore, the loading capacity and the structure of the irradiation box can be considered to reduce the minimum absorbed dose of food, thereby improving the energy utilization rate and production efficiency of γ-rays during food irradiation.关键词：γ-ray irradiation;Food irradiation;Unevenness;Ray utilization38|46|0更新时间：2025-02-28
RADIATION TECHNOLOGY APPLICATION
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Synthesis and properties of polymeric fluorescent probe sensitive to 4- nitrophenol and temperature AI导读
“在化学领域，研究人员合成了一种新型双重敏感型水溶性荧光聚合物，有效改善了有机小分子水溶性差、易脱落等问题。”摘要：In order to improve the properties of small organic molecules, such as poor solubility and easily falling off, a novel water-soluble polymer was synthesized. First, a fluorescent functional monomer (BSA) was synthesized using 4,4′-sulfonyldiphenol and methacryloyl chloride. Then, a fluorescent material, poly(BSA-co-AM-co-NIPAM) (PBAN), was synthesized through free-radical polymerization among N-isopropylacrylamide (NIPAM), acrylamide (AM), and acryloxydiphenylsulfone (BSA). The structure of the polymer was confirmed by 1H nuclear magnetic resonance and Fourier transform infrared spectroscopy analyses. The absorption and emission spectra of PBAN were obtained using a fluorescence spectrometer. The results indicated that PBAN showed strong fluorescence, with high stability and safety, and that the fluorescence intensity decreased with increasing temperature. This polymer showed high sensitivity to 4-NP, with a detection limit of 2.8 × 10-8 mol/L. A linear relationship for fluorescence detection was obtained in the range of (5.0~24.9) × 10-8 mol/L. Therefore, PBAN is expected to find use as a sensitively responsive probe for 4-NP detection..关键词：Fluorescent probe;Diphenyl sulfone;Polymer;Water-soluble29|69|0更新时间：2025-02-28 - “最新研究发现，通过热压法合成掺杂Zr的MAX相陶瓷，可显著提升Ti3SiC2的耐亚临界水腐蚀性能。”摘要：A Zr-doped MAX phase (Ti(1-x)Zr)3SiC2 ceramic (with a purity of approximately 97% and impurities of TiC) was synthesized using hot pressing to improve the subcritical water corrosion resistance of Ti3SiC2. After corrosion in deionized water at 360 °C and 18 MPa, a passivated corrosion layer was formed on the surface of the (Ti(1-x)Zrx)3SiC2 ceramic. The outer layer consisted of TiO2 and thex inner layer was a mixture of TiO2 and ZrO2. As Zr doping increased, the corrosion oxide layer on the surface of the (Ti(1-x)Zrx)3SiC2 ceramic became thinner. When the Zr doping was 15%, the change in quality of (Ti(1-x)Zrx)3SiC2 ceramic was the smallest and the oxide film the thinnest after corrosion; the thickness of the oxide film was 12 μm after 200 h of corrosion. At 15% Zr doping, the mechanical and thermal properties were excellent. The hardness, bending strength, and thermal conductivity of Ti3SiC2 ceramic are 3.2 GPa, (479.673 ± 10.012) GPa, and 33.93 W/(m∙K), respectively.关键词：Doping;Ti3SiC2;Subcritical water;Corrosion resistance;Coefficient of thermal expansion;Thermal conductivity23|20|0更新时间：2025-02-28
RADIATION INTERDISCIPLINARY RESEARCH
- “在二维材料制备领域，科学家提出了一种新方法，实现了氮化硼纳米片的高效剥离制备，并一步法制备出新型纳米金属催化剂，为相关研究开辟了新方向。”摘要：The fabrication of boron nitride nanosheets (BNNS) by the exfoliation of hexagonal boron nitride (h-BN) remains a challenging task in the field of two-dimensional material (TDM) preparation. Radiation-induced reduction-exfoliation (RIRE) is a new method of preparation of BNNS from h-BN. RIRE is achieved by the disruption of the interlayer interactions in a h-BN crystal by means of the volume expansion caused by the formation of Ni nanoparticles (NiNPs). NiNPs are formed via the radiation reduction of Ni2⁺ ions intercalated between the h-BN crystal layers. As a result, sheet-like NiNP (approximately 20 nm)-bound BNNS (Ni/BNNS) in 200 nm squares, with an average thickness of less than 5 nm, was successfully peeled from h-BN under ambient temperature and pressure conditions in an alcohol/water medium. The prepared Ni/BNNS exhibited excellent catalytic performance, good structural stability, and viability for magnetic separation, which make Ni/BNNS recyclable. More notably, when the water/methanol dispersion containing Ni/BNNS was exposed to simulated sunlight irradiation, H2 evolution of 8 404.3 μmol/g Ni within 2 h was detected. Therefore, this work provides a new means for the preparation of BNNS by the efficient exfoliation of h-BN, introduces a one-step preparation method for novel TDM-supported nano-metal catalysts, and offeres new insight into the catalytic mechanism of visible-light catalysts.关键词：Boron nitride nanosheet;γ-ray irradiation;Radiation reduction;Nano-metal catalyst;Photocatalytic hydrogen production45|52|0更新时间：2025-02-28
RESEARCH HIGHLIGHT
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