辐射蘑菇对大白鼠骨髓晚幼红细胞微核率的影响

随着原子能和平利用的日益广泛,辐照食品保鲜在世界各国蓬勃发展。但辐照食品是否有诱变活力,人畜食用是否有潜在的遗传危险,是人们关注的问题。过去对定期检查潜在性遗传危险的测定,是观察分析细胞分裂中期染色体畸变,但此法费时,步骤繁琐,分析细胞工作量甚大。近年来,一些遗传实验室、放射生物学实验室均利用哺乳动物骨髓细胞微核的出现率来初测各种可能具有诱发染色体畸变潜力的物质。我们的试验是用辐射蘑菇喂饲大白鼠来测定辐射蘑菇对大白鼠骨髓晚幼红细胞微核率的影响。     

累积γ辐射对大鼠血液生化和血象指标的影响

目的：探讨γ射线累积照射对大鼠血象和血液生化指标的影响。方法成年SD大鼠接受137 Cs γ射线照射（剂量率0．336 mGy/min）,累积剂量分别为0．5、1．0和2．0 Gy。照射结束后第2天和第11天,检测大鼠血象、WBC分类和血液生化指标。结果γ射线累积照射可造成受照大鼠WBC数在照后第2天显著降低;当累积剂量为1．0 Gy和2．0 Gy时,淋巴细胞比例持续降低,单核细胞比例持续升高,粒细胞比例暂时升高和HGB水平延迟性降低;血液生化指标中除尿酸外其它未见明显变化。结论γ射线累积照射对血液WBC及其分类有明显影响,对大鼠血液生化指标无明显影响。     

辐射及钙离子渗透处理对杧果贮藏过程中生理生化的影响

紫花杧果(Mangifera indica L.)经不同剂量~(60)Coγ辐照和Ca离子渗透处理,然后在26±1℃、RH为85%—90%下贮藏,定期测量苹果酸酶活性等性能,最后进行感官评定。结果表明:用Ca离子渗透结合辐照(0.25 kGy)处理,能明显地抑制苹果酸酶的活性,辐照还影响杧果中钙的运输、CO_2和乙烯的释放,感官评分最高。而单独Ca渗透处理对延迟后熟作用不明显。     

电子束辐照对进口葡萄色泽及保鲜效果的影响

以美国进口葡萄（无核红提）为试材,用剂量为0、0．56、1．11和2．10kGy的电子束辐照后分别于室温（13—17℃）下贮藏7d,低温（4℃±1℃）下贮藏15d。采用单-pH法和色度空间法测定果皮花青素含量和色差变化,用硬度计检测果肉耐压力。结果表明,电子束辐照导致葡萄果皮花青素含量下降,其下降幅度随剂量增加而加大,其中2．10kGy辐照果皮花青素含量显著低于未辐照处理。电子束处理对葡萄果实耐压力产生影响,但与剂量无相关性,其中室温贮藏葡萄的果实耐压力低于相应未辐照处理,低温贮藏15d时,0．56kGy电子束处理的果实耐压力高于相应未辐照处理。电子束处理可减少葡萄微生物数量,且剂量越高,微生物数量越少,腐烂率越低,可保证较好的防腐效果。     

低剂量辐射对小鼠血清蛋白差异表达的影响

应用蛋白质组学方法筛选对低剂量?射线敏感的蛋白质,并采用双向凝胶电泳和基质辅助激光解析飞行时间串联质谱技术分离、鉴定不同低剂量?射线导致的小鼠血清差异表达蛋白。不同低剂量?射线照射后,对实验组与对照组的血清双向电泳图谱进行比较分析,通过质谱鉴定得到7个差异表达点,分别是载脂蛋白C-III、?珠蛋白、腮腺分泌蛋白、?2巨球蛋白前体、转甲状腺蛋白晶体结构H链、C1qc蛋白和丛生蛋白。提示低剂量?射线辐照能导致小鼠血清中某些蛋白表达发生变化。     

γ辐射对30%TRPO-煤油萃取性能及物理参数的影响

测试了γ辐照剂量对国产三烷基氧膦(TRPO)萃取性能、反萃性能(U、Pu、Am、En、Pm)、物性参数(密度、粘度、折光率、紫外透光率)的影响。用红外光谱观察了辐解产物的特征峰,检出了聚合物、烷基膦酶、亚硝基化合物、硝基化合物、羰基化物等辐解产物,用简单的5%Na_2CO_3-1mol/L HNO_3-H_2O洗涤法,可把主要的辐解产物除去。研究结果表明:TRPO具有良好的辐照稳定性,可以安全地用于处理强放废液和某些超铀靶件。     

茶叶组分对硫丹和联苯菊酯辐射降解的影响

为探讨硫丹和联苯菊酯的辐照降解效果及茶叶中有效成分对两者降解的影响,利用60Coγ射线对硫丹和联苯菊酯的环己烷溶液进行辐照。研究了茶叶中茶多酚、咖啡碱、茶氨酸、维生素C等有效成分对硫丹和联苯菊酯辐射降解的影响。结果表明:同浓度的硫丹和联苯菊酯的辐射降解随吸收剂量的增加而增大,而在同一剂量下,硫丹的降解率随着浓度的增大而降低,联苯菊酯的降解却呈现先增加后降低的趋势;茶叶中的有效成分茶多酚、咖啡碱、茶氨酸及维生素C对硫丹的降解起促进作用,而茶多酚、咖啡碱及维生素C对联苯菊酯的降解起促进作用,茶氨酸则表现为抑制作用。     

辐照温度对双极线性稳压器的辐射效应影响

为研究辐照温度对线性稳压器的电离辐射效应的影响,选取三个公司生产的同一型号线性稳压器7805在不同温度条件下进行60Co?电离辐射效应试验。结果表明:辐照温度的增加使三款线性稳压器输出电压的辐射损伤增大;使国家半导体公司和安森美半导体公司稳压器的线性调整率及国家半导体公司的输入电流敏感参数的辐射损伤减小。结合双极晶体管的空间辐照效应模型,对双极线性稳压器不同温度条件下的辐射损伤效应进行了分析和讨论,表明辐照温度对线性稳压器的辐射敏感参数的影响主要取决于陷阱电荷。     

辐射对InSb霍尔器件电磁参数的影响

系统研究了低剂量率γ和β射线辐照对不同工作状态下的InSb霍尔器件输入电阻、输出电阻、磁电阻及霍尔灵敏度等电磁参数的影响,结果表明,γ和β粒子通过电离、位移效应与器件相互作用,导致器件的宏观电磁参数发生复杂变化.这些变化不因辐照停止而消失,反映了常温退火过程对辐射损伤的不可恢复性.恒流激励、无磁场作用时,所进行的辐照均使器件的输入电阻增加,并与辐照时间成正比.恒流激励、有确定磁场作用时,输入电阻、霍尔输出电压也因γ射线辐照而增加,但由于磁场的影响,增加量较小,且与辐照时间不成正比.无源、无磁场作用时,虽然输入、输出电阻因辐照而增加,但磁电阻和霍尔灵敏度却可能增加,也可能减小.所有这些结论对相应的辐射防护研究具有重要的参考价值.     

用ICP-AES法分析喂饲辐照食品的大白鼠血清中的微量元素

辐照保鲜是当前发展的一项新的食品保藏技术,其安全性为人们所关注。为此,近卅年来各国对辐照食品进行了大量的研究。结果证明经适当剂量辐照的食品是安全的。但随着生命科学的深入研究,揭示了某些微量元素对健康的密切关系,为此,测定辐照食品喂饲的大白鼠血清中微量元素的变化,以验证辐照食品的安全性。     

Upgrading of X-ray CT technology for analyses of irradiated FBR MOX fuel

The X-ray CT technology previously developed by JAEA was upgraded. The shape of the X-ray source beam was changed from a circular shape to an elliptical one and the collimator slit width was decreased from 0.3 to 0.1 mm. The X-ray detector was improved by changing a CdWO₄ scintillator to a highly sensitive silicon semiconductor detector. The analysis code of X-ray CT image was revised with respect to the number of points by using two kinds of experimental results and taking into account the effects of crack existence and deviation of the central void position from the radial center of a fuel pellet. As a result, high resolution X-ray CT images could be obtained on the transverse cross section of irradiated fuel assemblies. The error of the dimensional measurement was improved from ±0.1 to ±0.03 mm by upgrading the instrument and revising the analysis code of X-ray CT image. The discriminating accuracy of density difference could be increased, and the low density region (undisturbed region) and high density region (equi-axial and columnar regions) in the X-ray CT image on the cross section of irradiated fuel could be discriminated from each other. The reliability of fuel performance analysis improves because a large number of PIE data can be collected, compared with the conventional destructive PIE.     

离子束辐照下微生物,植物组织存活模型的研究

从低能离子辐照的能量沉积，质量沉积和电荷交换三要素出发，认为质，荷效应对ＤＮＡ具有间接的辐射保护作用，推导出了一个描述低能离子辐照下生物体的存活率公式，给出了典型曲线，并运用该公式对一些实验资料进行了很好的数据拟合，通过反证法，对质量沉积产物对ＤＮＡ具有损伤作用的假设提出质疑，进一步证明了所建模型之立论基础的可信性。     

Analysis of measured isotopic compositions by CASMO5 coupled with a JENDL-4.0 base library for irradiated fuel of light water reactors

Measured isotopic compositions of UO₂ and MOX fuel samples taken from irradiated light water reactor fuel assemblies were analyzed by CASMO5 coupled with a JENDL-4.0 base library to assess the uncertainties in the calculated isotopic compositions on heavy and fission product nuclides. The burnup calculations for the analysis were performed based on a single-assembly model taking into account the detail fuel assembly specifications and irradiation histories. For the MOX fuel samples, a multiple-assembly model was also adopted taking into account the effect of the surrounding UO₂ fuel assemblies. The average and standard deviation of the biases (C/E ? 1's (here C and E are calculated and measured results, respectively)) were calculated for each nuclide separately on the PWR and BWR UO₂ fuel samples. The averaged biases for ²³⁵U, ²³⁶U, ²³⁹Pu, ²⁴⁰Pu, ²⁴¹Pu and ²⁴²Pu were 2.7%, ?0.9%, 0.3%, 0.7%, ?2.4% and ?1.7% for PWR UO₂ samples, and 6.7%, ?1.5%, 2.5%, ?0.6%, 0.4% and ?0.1% for BWR UO₂ samples, respectively. The biases with the single-assembly model on the MOX fuel samples showed large positive values of ²³⁹Pu, and application of the multiple-assembly model reduced the biases as reported in our previous studies.     

剂量率对辐照牛血清蛋白生化特性和结构的影响

为研究高剂量率对牛血清辐照灭菌中的活性下降的抑制作用,将新生牛血清分别经平均剂量率为60、600 Gy/min钴源和300 k Gy/min电子加速器3种方式辐照30 k Gy后,分析牛血清蛋白的生化特性和结构变化及其与剂量率的关系。结果表明,与未辐照牛血清相比,辐照后蛋白浊度、疏水氨基酸荧光强度、放热峰出峰时间分别从0.742、24.1 u和16.5 min升高至0.802、99.3 u和17.2 min,而蛋白浓度、放热峰温度分别从0.473和76.4℃下降至0.444和74.5℃。电泳分析(SDS-PAGE)显示,600 Gy/min钴源辐照牛血清中相对分子质量为175 k Da和58 k Da的蛋白组分含量明显大于低剂量率辐照牛血清。经扫描电镜(SEM)分析,辐照后牛血清中沉淀部分呈现密集的网络结构,未沉淀部分呈现碎片和球状体混合的形貌结构,低剂量率辐照的样品蛋白球状体形貌不突出。可见高剂量率有抑制辐照灭菌牛血清蛋白分子变性的作用,3种方式中600 Gy/min钴源效果最明显。     

Analysis of core physics experiments on irradiated BWR MOX fuel in the REBUS program

Critical experiments were performed in the REBUS program on a core loaded with a test bundle including 16 irradiated BWR-type MOX rods of average burnup of 61 GWd/t. The experimental data were analyzed using diffusion, transport, and continuous-energy Monte Carlo calculation codes coupled with nuclear data libraries based on JENDL-3.2 or JENDL-3.3. Biases in effective multiplication factors of the critical cores were ?1.0%Δk for the diffusion calculations (JENDL-3.2), ?0.3%Δk for the transport calculations (JENDL-3.3), and 0.2%Δk for the Monte Carlo calculations (JENDL-3.2). The measured core fission rate and co-activation rate distributions were generally well reproduced using the three types of calculations. The burnup reactivity determined using the measured water level reactivity coefficients was ?2.41 ± 0.08%Δk/kk’, which also agreed with the results of the three type of calculations within the measurement and calculation errors. The most probable isotopic inventories in the irradiated MOX rods was tentatively obtained by using the ratios of the calculation to chemical assay data on a pellet sample, and the burnup reactivity was reanalyzed to split the calculation error into those due to the inventory and reactivity calculations. This approach showed that the inventory calculation error compensated the reactivity calculation error.     

Studies on innovative hydrogen recombiners as safety devices in the containments of light water reactors

In order to prevent the containment and other safety relevant components from incurring serious damage caused by a detonation of the hydrogen/air-mixture generated during a severe accident in light water reactors (LWR) passive autocatalytic recombiners (PAR) are used for hydrogen removal in an increasing number of European plants. These devices make use of the fact that hydrogen and oxygen react exothermally on catalytic surfaces generating steam and heat.

Experimental investigations at several research facilities indicate that existing PAR systems bear the risk of igniting the gaseous mixture due to an overheating of the catalyst elements caused by strong reaction heat generation. Innovative devices could overcome existing limitations making use of the knowledge deduced from experiments performed at the REKO facilities at Forschungszentrum Juelich (FZJ).

The paper analyses the mechanisms of the thermal behaviour of catalytic plate-type recombiners and presents experimental results on existing and innovative devices for hydrogen removal introducing the modular recombiner concept.     

Studies on mechanical, thermal and morphological properties of irradiated recycled polyamide and waste rubber powder blends

The aim of this article was to show the effect of gamma irradiation on mechanical and thermal properties of recycled polyamide (rPA) copolymer blended with different content of waste rubber powder (WRP). In order to study the structural modifications of prepared blends have been subjected to irradiation doses up to 200 kGy were applied to all samples. Non-irradiated blends were used as control samples. Mechanical properties, namely, tensile strength (TS), elastic modulus, elongation at break and hardness have been followed up as a function of irradiation dose and degree of loading with rubber content. Furthermore, the influence of radiation dose in the thermal parameters, melting temperature, heat of fusion, ΔH_f of the recycled PA and its blend with waste rubber powder (WRP) was also investigated.     

尼龙66/紫外辐照线性低密度聚乙烯共混物的力学性能

通过紫外辐照实现了高密度聚乙烯(HDPE)的官能化，改善了HDPE复合材料的性能。本工作采用傅立叶红外(FT-IR)、X射线光电子能谱(XPS)、凝胶、熔融指数和水接触角测试等研究了紫外辐照对线性低密度聚乙烯(LLDPE)化学结构和性能的影响。紫外辐照后，在LLDPE的分子链上引入了C=O、C-O和C(=O)O等含氧基团，其含量随辐照时间延长而增加。凝胶分析结果表明，紫外辐照过程中，LLDPE产生凝胶，