Effect of heavy-ion irradiation on dielectric constant and electrical conductivity of doped and undoped nonlinear substance

Implantations were carried out on gel-grown potassium dihydrogen orthophosphate (KDP) and those doped with magnesium oxide (MgO) single crystals using 100 MeV Ag⁺ heavy-ion beam of 15 UD 16 MV pelletron accelerator. To conduct a comparative study, measurements were carried out in the temperature range 243 K-403 K at frequencies ranging from 1 kHz-1 MHz on irradiated and nonirradiated nonlinear samples. It was observed that the mechanism of dielectric behaviour varied with frequency, temperature and ion irradiation. Further, implantation produced erratic variation in the conductivity both in the intrinsic and extrinsic regions, and also in the dielectric behaviour of the substance. The property of sensitive dependence on initial conditions, namely, chaos had set in after ion irradiation. However, the doping effect had not completely terminated the above transition, leading to chaos in the nonlinear medium.     

Stress assessment based on Ergonomics coupled with image-processing tools and techniques for lean product design and development

This paper presents an innovative lean ergonomic tool (LET) for mental stress through facial muscle activity assessment. An image-processing tool has been developed based on the analysis of facial angles. These angles were perceived by analyzing the stress levels of product development team members at certain conditions. A total number of 26 subjects participated in the experiments. On the basis of angular deviation levels, a stress level classification scheme was developed using neutral position of each team members for each task. Through statistical analysis, team members were divided into the groups of same degree of stress level. Each group was assigned a numerical expression value which was relative to the perceived stress level of that group for each task. Using five distinct action categories, a criterion for the evaluation of stress level was proposed which was validated through two distinct case studies. The developed LET will help the top management in taking corrective actions to reduce the stress level during product design and development.     

基于链路持续时间控制的VANET路由协议

在车辆自组织网络中,车辆的快速移动会使网络拓扑呈现高动态性,造成链路频繁断裂、路径不稳定。针对该问题,提出一种控制链路持续时间的路由协议。采用相同行驶方向且链路持续时间最长的节点组建路径,在路由维护阶段,设置定时器提前触发路由寻路,找到可替代的有效链路组建新路径。如果未能找到有效链路,则在链路两端节点增大发射功率,延长链路持续时间,扩大寻路搜索范围,最大限度减小链路断裂的概率。仿真实验结果表明,与AODV及LED-AODV协议相比,该路由协议在路径持续时间、传输延迟和吞吐率方面性能较好,具有更稳定的链路。     

车辆自组织网络中基于稳定路径的路由协议

车辆自组织网络中网络拓扑的高动态性及节点的高速移动会导致路径频繁断裂。针对该问题,提出一种基于稳定路径的路由协议。利用节点的移动信息预测链路的使用寿命连结失效时间（LET）,通过同方向行驶的节点组建链路,并选用最大LET的链路构建路径,使路径趋于稳定,同时减少控制开销。仿真结果表明,与DSR算法相比,该路由协议能增强路由稳定性,提高网络吞吐量。     

LET模型的时间语义编程语言

嵌入式实时系统的正确性不仅取决于计算结果的正确性,更取决于产生结果时间的正确性.然而软件不确定的并发执行带来系统时间行为不可预测问题,使得验证复杂度升高,成本增加,为此实时系统领域提出了许多实时编程语言来提高系统的时间可预测性.LET(logical execution time)模型结合了同步模型ZET(zero e...     

MOSFET单粒子翻转效应的二维数值模拟

用MEDICI二维模拟软件对MOSFET的单粒子翻转现象进行了计算，力图从理论上建立分析器件单粒子翻转的可靠手段，通过输入不同粒子的线性能量传输值，得到了某一结构器件的翻转概率与线性能量传输值的关系曲线，分析了不同结构参数的变化对单粒子翻转的影响，模拟得到的结果与电荷漏斗模型相吻合，表明所建立的物理模型的正确性。     

O-GlcNAcylation Affects the Pathway Choice of DNA Double-Strand Break Repair

Exposing cells to DNA damaging agents, such as ionizing radiation (IR) or cytotoxic chemicals, can cause DNA double-strand breaks (DSBs), which are crucial to repair to maintain genetic integrity. O-linked β-N-acetylglucosaminylation (O-GlcNAcylation) is a post-translational modification (PTM), which has been reported to be involved in the DNA damage response (DDR) and chromatin remodeling. Here, we investigated the impact of O-GlcNAcylation on the DDR, DSB repair and chromatin status in more detail. We also applied charged particle irradiation to analyze differences of O-GlcNAcylation and its impact on DSB repair in respect of spatial dose deposition and radiation quality. Various techniques were used, such as the γH2AX foci assay, live cell microscopy and Fluorescence Lifetime Microscopy (FLIM) to detect DSB rejoining, protein accumulation and chromatin states after treating the cells with O-GlcNAc transferase (OGT) or O-GlcNAcase (OGA) inhibitors. We confirmed that O-GlcNAcylation of MDC1 is increased upon irradiation and identified additional repair factors related to Homologous Recombination (HR), CtIP and BRCA1, which were increasingly O-GlcNAcyated upon irradiation. This is consistent with our findings that the function of HR is affected by OGT inhibition. Besides, we found that OGT and OGA activity modulate chromatin compaction states, providing a potential additional level of DNA-repair regulation.     

高能重离子诱发核反应中灰粒子产生

采用ＥＭＵ０１国际合作组的原子核乳胶为探测器,系统地研究了能量为１４．６,６０,２００ＧｅＶ／ｕ的＾１６Ｏ核,２００ＧｅＶ／ｕ的＾３２Ｓ诱发核反应产生的灰粒子平均多重数及角分布,以描写相对论性核－核碰撞的ＬＵＣＩＡＥ模型为基础,进行ＭｏｎｔｅＣａｒｌｏ模拟的结果与实验数据一致。