利用同步辐射XRD研究BiFeO3 外延多铁薄膜的微结构

使用脉冲激光沉积在SrTiO₃ 衬底上生长了不同厚度的BiFeO₃(BFO)薄膜, X 射线衍射分析表明薄膜是BFO 外延薄膜. X 射线反射率测量发现BFO 薄膜密度随着厚度的增加而增加, 同时薄膜表面存在厚度为数纳米的非设计覆盖层. 随着厚度的增加, BFO 薄膜由完全应变过渡到应变部分弛豫状态, 同时BFO 从四方相转变为单斜相.     

变包含角平面光栅单色器及其关键技术

分析设计并研制了上海光源软X 射线谱学显微光束线站的变包含角平面光栅单色器, 经过精密加工调试, 保证了扫描系统的转角重复精度; 采用多孔腔内部通道水冷方法, 控制了镜子表面热变形; 完成真空箱体大尺寸方法兰加工与密封, 达到了单色器工作所需的超高真空. 通过上述关键部件的精确掌控, 确保了单色器主要性能——光子能量范围、能量分辨率和能量重复性, 均优于设计指标.     

阈值光电子-光离子符合速度成像技术的初步应用

基于同步辐射的闲值光电子-光离子符合速度成像技术采用双速度聚焦电场同时控制电子和离子的飞行轨迹,提高了收集效率和能量分辨率.应用该技术开展了一些原子和分子的实验研究,分别测量了相应的阈值光电子谱、阈值光电子-光离子符合质谱、阈值光电子-光离子符合光谱和阈值光电子-光离子符合速度成像,展现了该技术在离子结构分析、混合物成分辨别和具有态选择的离子解离动力学等方面的初步应用.     

Application of synchrotron source based DEI method in guinea pig cochleae imaging

Hard X-ray diffraction enhanced imaging (DEI), which is based on a synchrotron source and monochromator-analyzer-crystal system, is an effective method for imaging X-ray phase shift. Utilizing an analyzer crystal with high angular sensitivity of micro-radian, DEI can measure the transmitted, refracted and scattered X-rays when projecting onto a sample. It dramatically improves the contrast and spatial resolution of the resultant images. At the topography station of Beijing Synchrotron Radiation Facilities (BSRF), we implemented DEI method in guinea pig cochleae imaging and acquired a series of DEI images. Based on these images, the apparent absorption and refraction images were calculated. The DEI images revealed the holistic spiral structures and inner details of guinea pig cochleae clearly, even including the structures at the cellular level, such as the static cilia of hairy cells and the limbus of Hansen cell. Due to the advantages of high contrast, high spatial resolution and distinct edge-enhanced effect, DEI method promises extensive applications in biology, medicine and clinic in the near future.     

一个柱样品的中子注量衰减和γ射线自吸收修正的统一计算方法

从中子和γ射线的实际输运过程出发,推导出了一个柱样品的中子注量衰减和γ自吸收修正的统一计算公式.在推导中考虑了这两种效应的位置关联用不同方法对这个公式的计算结果进行了检验,证明这个统一计算公式物理图像清晰,计算速度快,结果可靠,适用于快中子核反应的伴生γ射线截面测量中的数据处理.     

考虑同步自吸收的γ暴能谱

重点讨论有自吸收的γ射线暴余辉的能谱，考虑了在火球模型中同步加速辐射中的自吸收效应，用含有吸收系数的同步加速辐射谱公式计算了GRB970508余辉的辐射谱．解释了GRB970508射电和光学波段余辉的光变曲线的特征．     

一种新型同步辐射第一晶体驱动转轴系统

以研究第三代同步辐射双晶单色器第一晶体新型转轴驱动系统为目的．分析了现有技术,阐述了新型第一晶体驱动转轴系统的原理、结构及其创新特点．研究结果表明,此种机构,运转灵活,无泄漏,完全符合第三代同辐射光源的使用要求．     

SSRF中高热载挡光器的热-应力分析

上海同步辐射装置（SSRF）为第三代同步辐射装置,其设计能量为3．5GeV,最大流强为300mA,SSRF中生物大分子光束线（U21）的前端区将接收总功率为4．36kw、峰值功率密度高达44kW／mrad^2的光束,前端装置中的挡光器将阻挡全部的光束,所以挡光器的热-应力分析在前端区设计中是非常关键的．通过有限元方法,分析了挡光器在热交换系数为0．015W／mm^2、冷却水温度为30℃的工作条件下,挡光器的最高温度、最高冷却槽壁温以及最大热应力．分析结果得出挡光器的应力问题是挡光器设计的难点,为了减小挡光器工作时的热应力,对挡光器的结构进行了改进,并给出了其热-应力分析结果．     

Influence of crystal materials on the synchrotron X-ray fluorescence analysis: A study of crystal and amorphous clinopyroxene

Synchrotron X-ray fluorescence analyses of crystal and amorphous clinopyroxene were compared. The results showed that using the synchrotron X-ray as a source of energy, the diffraction X-ray of crystal materials will seriously affect the X-ray fluorescence analysis. In order to avoid the influence of diffraction, the best way to solve it is to use the monochromatic source, or to have a collimating slit between sample and Si (Li) detector.     

Chenguodaite (Ag_9FeTe_2S_4):a new tellurosulfide mineral from the gold district of East Shandong Peninsula,China

Chenguodaite, approved by IMA-CNMMN (2004-042a), was discovered in the Bunan quartz vein-type gold deposit in the gold district of East Shandong Peninsula. The mineral occurs in high grade Au-Ag-Cu ores, coexisting with galena, chalcopyrite, hessite, electrum, unnamed Ag6TeS2 and Ag16FeBiTe3S8, enclosed and replaced by native silver and acanthite. In the reflected light microscope, the mineral has light gray color, indistinguishable anistropism and hardness around 2―3. The color indices of chenguodaite relative to ICE C illuminator are: x=0.3027, y=0.3076, Y=25.78%, λd=474 nm, Pe=3.68%, similar to those of canfieldite. The average chemical composition from 16 microprobe analyses is Ag8.97Fe1.00Te1.99S4.04, idealized to Ag9FeTe2S4. The polycrystalline X-ray diffraction of chenguodaite by Gandolfi camera and synchrotron oscillation photography results in 67 reflections with the 12 strongest being (relative intensity in bracket): 6.742(69), 6.416(39), 5.951(33), 3.265(100), 2.981(24), 2.649(22), 2.25(24), 2.188(71), 2.142(22), 2.123(31), 2.044(23), 1.949(33), which are indexed to a primitive orthorhombic cell with a=12.769 (2) , b= 14.814(2), c= 16.233 (1) , V= 3070.63, Z = 9, Dcal.=6.85 g/cm3. The name is for the late Prof. Chen Guoda, a famous Chinese geologist and the founder of Diwa-Geodepression theory of tectonics.