5种植物精油对玉米象的杀虫活性研究

旨在筛选新型安全、环保的植物源杀虫剂,研究了 5种植物精油不同浓度及处理时间对玉米象熏蒸活性的效果,并分析了罗勒精油和薄荷精油主要成分对玉米象的熏蒸活性.研究表明,体积分数为40.00μL/L、处理时间为24、48、72、96 h时,薄荷精油和罗勒精油对玉米象熏蒸的校正死亡率分别为87.50％、95.00％、100％、...     

硅离子注入对全耗尽SIMOX材料总剂量效应的影响

Total dose hardened fully-depleted SOI materials are fabricated on separation by implanted oxygen （SIMOX） materials by silicon ion implantation and annealing. The ID-VG characteristics of pseudo-MOS transistors pre- and post-irradiation are tested with ^60Co gamma rays. The chemical bonds and the structure of Si in the buried oxide are also studied by X-ray photoelectron spectroscopy and cross-sectional high-resolution transmission electron microscopy, respectively. The results show that Si nanocrystals in the buried oxide produced by ion implantation are efficient deep electron traps, which can significantly compensate positive charge buildup during irradiation. Si implantation can enhance the total-dose radiation tolerance of the fully-depleted SOI materials.     

双极晶体管的低剂量率电离辐射效应

通过对npn管和pnp管进行不同剂量率的电离辐射实验,研究了双极晶体管的低剂量率辐射效应.结果表明,双极晶体管在低剂量率辐照下电流增益下降更为显著,这是由于低剂量率辐照在氧化层中感生了更多的净氧化物正电荷浓度,致使低剂量率下过量基极电流明显增大.而辐照后npn管比pnp管具有更大的有效表面复合面积,致使前者比后者有更大的表面复合电流,从而导致了在各种剂量率辐照下,npn管比pnp管对电离辐射都更为敏感.     

鼻咽组织光热响应研究

利用生物传热理论模型Pennes方程对Ar^ 激光辐照下生物组织的温度分布进行模拟研究;实验测定了离体猪鼻咽组织存Ar^ 激光(λ=488．0nm和514．5nm)辐照下不同位置的温度分布．重点研究了辐照功率密度和波长对组织中温度分布的影响。理论和实验结果表明：组织中的温度分布与组织不同深部位置、激光波长以及激光辐照功率密度有关;实验获得波长488nm和514．5nm的Ar^ 激光分别辐照鼻咽组织时安全光剂量分别为1．85W／cm^2和1．72W/cm^2。     

电子束辐照对泥蚶肉挥发性风味成分的影响

目的:分析电子束辐照对泥蚶肉挥发性风味成分的影响。方法:以泥蚶为原料,采用固相微萃取-气质联用分析不同剂量电子束辐照后泥蚶肉的挥发性风味成分。结果:1)经1～9kGy剂量辐照,泥蚶肉挥发性风味成分的种类由46种分别增至55、57、52、58和66种;各剂量组羰基化合物含量最高,是泥蚶肉的主体风味成分;酮类赋予泥蚶肉甜花香,醛类则赋予泥蚶肉的脂香及瓜果香味。7kGy组泥蚶肉的异味可能与其高含量的挥发性羰基化合物有关。2)3kGy、5kGy组泥蚶肉的挥发性醇类相对含量增加,其中烯醇类化合物可赋予肉品柔和的香味。辐照后部分烯烃含量降低,一定程度上减少了泥蚶肉的腥味。3)辐照后杂环化合物的相对含量有所增加,其中呋喃类物质赋予泥蚶多种果香味,而吡啶、噻唑等贡献泥蚶炸肉、坚果等风味。5kGy组泥蚶肉中芳香族化合物相对含量最高,其中苯甲醛具杏仁香,可改善泥蚶固有风味。结论:3～5kGy辐照剂量对泥蚶肉原有风味不会产生明显的影响,甚至在一定程度上改善其风味。     

食源性内分泌干扰物联合效应研究进展

食源性内分泌干扰物(endocrine disrupting chemicals,EDCs)因具有相似的作用终点,低剂量下混合暴露可能产生大于单一暴露的联合效应,已成为影响食品安全的一类重要风险因子,国际上已开始关注低剂量下混合暴露所引起的联合效应问题。本文首先对食源性EDCs的污染现状和检测技术(包括前处理技术和高通量检测技术)进行了梳理分析,基于气相色谱-质谱、液相色谱-质谱的分析技术已经成为EDCs的主流分析技术。随后,探讨了模式生物和毒性替代测试在联合效应研究中的研究现状,最后从浓度相加模型、独立作用模型和相互作用模型等3个方面介绍了联合效应评价方法的研究进展。基于毒性测试替代技术的联合效应研究将为科学评价食源性EDCs的联合效应,揭示联合效应产生的分子机制,修订食源性EDCs的安全限量标准提供依据。     

2014—2017年广东省阳江核电站连续监测γ空气吸收剂量率的质量控制

介绍了广东省阳江核电站2014—2017年连续监测γ空气吸收剂量率的监测设备、运行的质量控制措施,通过月巡检、仪器比对、放射源测试等措施,保证了监测结果的准确性。     

A review of botanical characteristics, phytochemistry, clinical relevance in efficacy and safety of Lycium barbarum fruit (Goji)

Lycium barbarum has been used as a traditional Chinese medicine (TCM) to nourish liver and kidney, and brighten the eye. The fruits are dried or freshly squeezed for their juice and concentrated for beverages. Among various constituents, a group of polysaccharides (LBP) with a Glycan-O-Ser glycopeptide structure has been most researched and considered to be important for the efficacy of L. barbarum. Studies indicate effects of L. barbarum on aging, neuroprotection, general well-being, fatigue/endurance, metabolism/energy expenditure, glucose control in diabetics, glaucoma, anti-oxidant properties, immunomodulation, anti-tumor activity and cytoprotection. In addition to TCM, L. barbarum can be sold as a dietary supplement or classified as a food based upon the long and safe traditional usage. This review is to provide background and updated information of chemical constituents and efficacies with safety including a new direction for research and current regulatory situation of L. barbarum.     

Effect of Gamma Irradiation on Molecular Structure and Physicochemical Properties of Corn Starch

ABSTRACT:  Carboxyl content and amylose leaching of gamma-irradiated corn starch increased and swelling factor decreased with increasing radiation dose. The apparent amylose content decreased gradually from 28.7% for native starch to 20.9% for 50 kGy irradiated starch. The proportion of short amylopectin branch chains (DP 6 to 12) increased, while the proportion of longer branch chains (DP ≥ 37) decreased with increasing radiation dose. The relative crystallinity and the degree of granule surface order decreased from 28.5% and 0.631 in native starch to 26.9% and 0.605 in 50 kGy irradiated starch, respectively. Pasting viscosity and gelatinization temperatures decreased with an increase in radiation dose. At a high dose (50 kGy), melting of amylose–lipid complex in DSC thermogram was not observed. The rapidly digestible starch (RDS) content slightly decreased up to 10 kGy but increased at 50 kGy. The resistant starch (RS) content slightly decreased at 2 kGy and then increased up to 50 kGy. The slowly digestible starch (SDS) content showed the opposite trend to RS content. Slower irradiation dose rate reduced carboxyl content, swelling factor, and amylose leaching. The apparent amylose content and amylopectin chain length distribution were not significantly affected by dose rate of gamma irradiation. However, the relative crystallinity and gelatinization enthalpy increased with slower dose rate. Slower dose rate decreased RDS and SDS contents, and increased RS content.     

不同电子束辐照处理对传统镇巴腊肉品质的影响

为研究电子束辐照对传统镇巴腊肉品质的影响,对不同剂量（0～8 kGy）电子束辐照处理的腊肉进行测定。结果表明：电子束辐照处理能减少腊肉中的菌落总数,随着辐照剂量的增大,腊肉的硬度降低,过氧化值、蛋白羰基含量逐渐增加,过氧化值、蛋白羰基含量在8 kGy剂量下达到最高,分别为0.047 g/100 mg、3.84 nmol/mg;2 kGy剂量组的腊肉在有效降低菌落总数的同时,也较好维持了腊肉的色泽、质构、脂肪及蛋白氧化程度,品质较优;电子鼻测定结果表明,2 kGy剂量组与对照组腊肉的总体风味较为接近,与感官评价结果一致。综合考虑,2 kGy是电子束辐照传统镇巴腊肉的适宜剂量。