低能重离子激发靶原子内壳层X射线的空穴产生机制     

李耀宗  张小安  马晴 《咸阳师范专科学校学报》2014,(6):14-17

在重离子与靶原子直接碰撞导致原子内壳层空穴产额与离子入射动能关系的基础上,计算了单离子入射引起的原子间碰撞产生的原子内壳层空穴产额。给出了低能重离子与靶原子碰撞过程,原子内壳层X射线单离子产额与离子动能的关系。较好地解释了动能300~600 ke V的Xe^27＋离子入射Mo靶,激发的Mo的L X射线的实验结果。  相似文献   

Materials and techniques of gilding on a suite of French eighteenth-century chairs     

Raina Chao  Arlen Heginbotham  Lynn Lee  Giacomo Chiari 《文物保护研究》2014,59(2):102-112

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Evolution of Surface Oxide Film of Typical Aluminum Alloy During Medium-Temperature Brazing Process简   总被引：1，自引：0，他引：1  

程方杰  赵海微  王颖  肖兵  姚俊峰 《天津大学学报(英文版)》2014,20(1):54-59

The evolution of the surface oxide film along the depth direction of typical aluminum alloy under medium-temperature brazing was investigated by means of X-ray photoelectron spectroscopy （XPS）. For the alloy with Mg content below 2.0wt%, whether under cold rolling condition or during medium-temperature brazing process, the en-richment of Mg element on the surface was not detected and the oxide film was pure Al2O3. However, the oxide film grew obviously during medium-temperature brazing process, and the thickness was about 80 nm. For the alloy with Mg content above 2.0wt%, under cold rolling condition, the original surface oxide film was pure Al2O3. However, the Mg element was significantly enriched on the outermost surface during medium-temperature brazing process, and MgO-based oxide film mixed with small amount of MgAl2O4 was formed with a thickness of about 130 nm. The alloy-ing elements of Mn and Si were not enriched on the surface neither under cold rolling condition nor during medium-temperature brazing process for all the selected aluminum alloy, and the surface oxide film was similar to that of pure aluminum, which was almost entire Al2O3.  相似文献   

Thermal plasma synthesis of SiC     

Muralidharan Ramachandran  Ramana G. Reddy 《上海大学学报(英文版)》2013,(1):50-61

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X射线线阵探测器在输送带检测系统中的应用     

王明生  李铁鹰  陈政石 《茂名学院学报》2011,21(1):33-36

为了解决传统的磁检测技术在钢绳芯输送带检测系统无法消除各种外界＂噪声＂干扰,以及因技术本身缺陷无法获得钢绳芯输送带内部钢绳芯直观的可视图像的问题,介绍了一种应用X射线线阵探测器的新型矿用钢绳芯输送带无损检测系统的原理以及应用。该系统可对输送带的全幅面进行不停机在线检测,从而使用户能更清楚、直观地看到损伤点或接头的透视图像,以便于采取进一步的合理修复手段,防范隐患扩大或事故发生。  相似文献   

题目：基于同步辐射技术研究金属锌蒸汽在飞灰小颗粒表面的凝结特性     

Xu CAI  Qun-xing HUANG  Moussa-mallaye ALHADJ-MALLAH  Yong CHI  Jian-hua YAN 《浙江大学学报(A卷英文版)》2015,(1):70-80

目的：寻找金属污染物在热转化过程中的生成和迁移规律,为可燃固体废弃物高效清洁能源化利用提供科学指导。方法：飞灰采自两台不同类型在运行固废焚烧炉;采样位置位于烟气净化系统之前以规避干扰;利用同
　　步辐射技术中的X射线近边吸收结构和吸收精细结构谱图结合热力学模拟对金属锌的形态进行分析和研究。结论：1.金属锌在炉排炉飞灰小颗粒上主要以氯化物形式存在,而在流化床飞灰小颗粒上是以铝硅酸盐为主;2.燃烧过程中的高硫氮比能够有效减少锌有毒形态的生成;3.硅、铝和钙基材料是锌蒸汽有效的吸附剂。  相似文献   

Body composition characteristics of elite Australian rugby union athletes according to playing position and ethnicity     

Adam J. Zemski  Elizabeth M. Broad 《Journal of sports sciences》2015,33(9):970-978

This study describes the body composition traits of modern-day elite rugby union athletes according to playing position and ethnicity. Thirty-seven international Australian rugby athletes of Caucasian and Polynesian descent undertook body composition assessment using dual-energy X-ray absorptiometry and surface anthropometry. Forwards were significantly taller, heavier and had a greater total fat mass and lean mass than backs. Backs displayed a higher percentage lean mass and lower sum of seven skinfolds and percentage fat mass. While no whole body composition differences were seen between ethnicities, significant regional differences were observed. In the periphery (arm and leg) regions, Polynesians had a greater proportion of fat mass (53.1% vs. 51.3%, P = 0.052, d = 0.5) and lean mass (49.7% vs. 48.6%, P = 0.040, d = 0.9), while in the trunk region a lower proportion of fat mass (37.2% vs. 39.5%, P = 0.019, d = 0.7) and lean mass (45.6% vs. 46.8%, P = 0.020, d = 1.1). Significant differences were also seen between Caucasian and Polynesian forwards in leg lean mass (31.4 kg vs. 35.9 kg, P = 0.014, d = 2.4) and periphery lean mass (43.8 kg vs. 49.6 kg, P = 0.022, d = 2.4). Elite Polynesian rugby athletes have different distribution patterns of fat mass and lean mass compared to Caucasians, which may influence their suitability for particular positions.  相似文献   

Copper vanadate minerals found in mediaeval mural paintings     

《文物保护研究》2013,58(3):183-186

Abstract

A yellowish copper vanadate mineral has been found in Swedish mural paintings from the fifteenth century. Small patches occur in malachite-green paint. Thirteen samples from five churches have been analyzed by optical and scanning electron microscopy with energy–dispersive X-ray spectrometry, transmission electron microscopy, X-ray powder diffraction, and polarized light microscopy. The substance is evidently the rather uncommon mineral volborthite, with the chemical formula Cu₃V₂O₇(OH)₂.2H₂O. Very small quantities have also been noted for another mineral, presumably calcio-volborthite, CaCu(VO₄)(OH), also named tangeite. The results show that the conservator should always be observant for pigments not earlier noticed or reported. There are some old mines in Central Europe, e.g. in Germany, which contain malachite as well as copper vanadate minerals, and this is probably the origin of the yellow patches in the paintings.  相似文献   

体操对专业运动员腕部骨关节影响的调查分析     

屈德新 《北京体育大学学报》2006,29(8):1084-1086

为了研究应用医学影像的方法分析体操运动员的腕部骨与关节的特征,探讨其X线表现类型及特点.对体操运动员的腕部正侧位进行X线检查分析,全部病例的X线分析基于常规X线平片和基本的医学影像知识并结合运动医学知识.结果发现:体操运动员X线征象主要表现为骨骺异常、骨质增生、骨折等.说明,长期的身体局部超负荷练习极易造成身体局部训练负担过重.从而产生体操运动员腕部骨、关节的变异和损伤,这些变化与运动员的年龄、运动史、运动项目特点等有密切联系.  相似文献   

单辊法制备Co43Fe20Ta5.5B31.5非晶合金带材     

王冰霞  王鑫 《天水师范学院学报》2007,27(2):68-70

介绍了制备Co43Fe20Ta5.5B31.5非晶合金薄带的准备过程,综述了单辊法制备Co43Fe20Ta5.5B31.5非晶合金带材的工艺流程和影响参数,并通过XRD测试不同辊面线速度制备出的Co43Fe20Ta5.5B31.5带材都为非晶。对单辊法制备非晶合金薄带有一定的指导意义。  相似文献