In-situ TEM observation of the evolution of helium bubbles in Mo during He+ irradiation and post-irradiation annealing

The evolution of helium bubbles in purity Mo was investigated by in-situ transmission electron microscopy (TEM) during 30 keV He⁺ irradiation (at 673 K and 1173 K) and post-irradiation annealing (after 30 keV He⁺ irradiation with the fluence of 5.74×10¹⁶ He⁺/cm² at 673 K). Both He⁺ irradiation and subsequently annealing induced the initiation, aggregation, and growth of helium bubbles. Temperature had a significant effect on the initiation and evolution of helium bubbles. The higher the irradiation temperature was, the larger the bubble size at the same irradiation fluence would be. At 1173 K irradiation, helium bubbles nucleated and grew preferentially at grain boundaries and showed super large size, which would induce the formation of microcracks. At the same time, the geometry of helium bubbles changed from sphericity to polyhedron. The polyhedral bubbles preferred to grow in the shape bounded by {100} planes. After statistical analysis of the characteristic parameters of helium bubbles, the functions between the average size, number density of helium bubbles, swelling rate and irradiation damage were obtained. Meanwhile, an empirical formula for calculating the size of helium bubbles during the annealing was also provided.     

一种基于特征值反求的复合材料层合板波动特性的近似修改方法

采用一种特征值反求形式的方法用来近似层状复合板的波动特性修改。通过敏感度分析,确定层合板中能最显著地改变结构波动特性的结构参数为设计变量。采用二阶泰勒展式近似特征值和特征频率相对于设计变量的改变率。计算了不同结构变化时的色散特性,并与精确计算结果进行了比较。结果证明本方法对于层状复合板波动特性修改的近似是可行并且有效的。     

“K90介质陶瓷材料的研制”国家级项目落户鲁颖电子

<正>在继国家"双加"工程技术改造项目、第四批国债专项资金重点技术改造项目、国家"863"计划及国家发改委高新技术产业化专项等6个国家级项目之后,2010年6月,山东同方鲁颖电子有限公司又将一国家     

基于JSP的钢铁企业船运信息系统

介绍钢铁企业船运原料的信息系统。根据物流的要求,系统在设计中采用了JSP技术,遵循软件开发的流程,模块划分明确,功能设计有较强的针对性。此外,灵活运用了JSP的对象技术,并且使用有效的SQL语言操作后台数据库,实现了企业船运原料的信息化管理。     

IEC 62228-3:2019标准中的静电放电试验规范及其试验方法分析

IEC62228-3:2019是国际电工委员会(IEC)制定的关于集成电路CAN(控制器局域网)收发器的电磁兼容评估标准.本文对标准中的静电放电试验方法进行了分析,并对静电放电的试验配置和方法进行了总结,详细阐述了CAN收发器在接触放电试验中的实际应用.     

株洲广播电视台媒资系统建设

本文介绍了媒资系统的基本概念,结合株洲广播电视台媒资系统的建设介绍了媒资系统的设计思路,媒资系统的组成、各子系统功能等,最后简单介绍了媒资系统的实施和实际运行情况。     

Formation Mechanism and Stability Study of Konjac Glucomannan Helical Structure

The formation mechanism and stability of konjac glucomannan (KGM) helical structure were investigated by molecular dynamic simulation and experimental method. The results indicate that the molecular conformation of KGM is a non-typical helical structure. In detail, helical structure of KGM is mainly sustained by acetyl group, whose size and stability are affected by the molecular polymerization degree of KGM. In vacuum among the non-bonding interactions, electrostatic force is the greatest factor affecting its helical structure, but in water solution, hydrogen bond affects the helical arrangement greatly. To our interest, temperature exhibits a reversible destroying effect to some extent; the helical structure will disappear completely and present a ruleless clew-like arrangement till 341 K. This work suggests that the method of combining molecular dynamic simulation and experiment tools can be effective in the study of KGM helical structure.     

轴向分区双频磁绝缘线振荡器的数值模拟

 为了便于模式变换器的设计,达到双频微波都能集中辐射的目的,提出一种轴向分区的双频磁绝缘线振荡器,该器件束波互作用区为中间隔开、两端不同周期、不同深度的慢波结构,使电子在上下游与不同频率特性的慢波结构进行束波互作用,得到稳定的双频微波输出。使用2.5维全电磁粒子模拟软件进行数值模拟,在工作电压450 kV,电流40 kA条件下输出微波功率为1.4 GW,功率效率约为7%,输出的微波频率分别为1.25 GHz和1.65 GHz,两者频谱幅度相差约为1.5 dB,模式为TEM模。     

两相滴定法研究2-乙基己基膦酸单2-乙基己基酯从盐酸介质中萃取钕(Ⅲ)的动力学

本文利用两相滴定法作为分析手段,用恒界面池搅拌法考察了多种因素对2-乙基己基膦酸单2-乙基己基酯(HEHEHP,HA)从盐酸介质中萃取Nd(Ⅲ)动力学的影响,从实验结果推论出萃取过程为界面化学反应控制型机理。     

等离子淋浴在离子注入工艺中的应用

阐述了等离子淋浴技术的工作原理和特点。介绍了在离子注入工艺中采用等离子淋浴来中和晶片表面的电荷积累,可将晶片表面的电荷积累电压控制在安全范围;应用等离子淋浴实现低能离子束的电中性传输,可提高低能离子束的传输效率和束通道的最大传输束流。最后介绍了国外在这两方面的研究应用情况。