Experimental quantification of annular dark-field images in scanning transmission electron microscopy

This paper reports on a method to obtain atomic resolution Z-contrast (high-angle annular dark-field) images with intensities normalized to the incident beam. The procedure bypasses the built-in signal processing hardware of the microscope to obtain the large dynamic range necessary for consecutive measurements of the incident beam and the intensities in the Z-contrast image. The method is also used to characterize the response of the annular dark-field detector output, including conditions that avoid saturation and result in a linear relationship between the electron flux reaching the detector and its output. We also characterize the uniformity of the detector response across its entire area and determine its size and shape, which are needed as input for image simulations. We present normalized intensity images of a SrTiO(3) single crystal as a function of thickness. Averaged, normalized atom column intensities and the background intensity are extracted from these images. The results from the approach developed here can be used for direct, quantitative comparisons with image simulations without any need for scaling.     

Effects of tilt on high-resolution ADF-STEM imaging

A study of the effects of small-angle specimen tilt on high-resolution annular dark field images was carried out for scanning transmission electron microscopes with uncorrected and aberration-corrected probes using multislice simulations. The results indicate that even in the cases of specimen tilts of the order of 1 degree a factor of 2 reduction in the contrast of the high-resolution image should be expected. The effect holds for different orientations of the crystal. Calculations also indicate that as the tilted specimen gets thicker the contrast reduction increases. Images simulated with a low-angle annular dark field detector show that tilt effects are more pronounced in this case and suggest that these low-angle detectors can be used to correct specimen tilt during scanning transmission electron microscopes operation.     

试论《四库全书》的编纂及其盐文献

《四库全书》采进书多来自盐区藏书家,大量的盐文化圈学者也参与了该书的编纂,它应该最能反映当时的盐文化成果。《四库全书总目》的“提要”对《四库全书》收录的盐政、盐史等盐文献的介绍。该书“阐明性学治法”的编纂宗旨,价值尺度的保守和思维方式的滞后使得其中的盐业科技、管理等文献不如想象中丰富。盐业科技、物质文化的发达并未能将整个社会文化推进到以实证为基础的现代文明的新时代。     

马2断块油藏形成的控制因素及勘探建议

通过对马2断块地层沉积相、构造及油藏类型的分析介绍，参考马2断油藏储层基本特征、油藏开发动态、油气显示和数值模拟最新研究结果，根据马2断块区域石油地质条件，对马2断块油藏形成的控制因素进行了深入分析、研究，明确提出“储集沙全及断裂系统的发育和断裂性质是该区块油藏形成的主要控制因素”的观点。并结合剩余油分布特点，提出了进一步勘探的建议，为马2断块油藏的控潜和勘探目标的选择指明了方向。     

"双高期"油藏剩余油分布规律及挖潜对策

利用物理模拟驱油机理实验、岩心观察油层水洗状况、微观驱油实验、示踪迹监测、碳氧比、中子寿命测试以及数值模拟结果,建立断块各小层砂体水淹模式图及剩余油饱和度等值图,从定性认识到定量分析,详细研究了该断块的水淹特征及剩余油分布规律,并探索出针对“双高期”老油田不同剩余油潜力区分布特点进行挖潜对策的综合调整模式,为同类油田开发调整提供借鉴。     

利用TM数据估算山丹军马场的植被生物量

山丹军马场是我国面积最大的马场,近年来由于过度放牧和不合理开发,植被正在逐渐退化。所以植被的生长状况的研究就显得特别重要。利用2003年9月的Landsat TM图像估算了山丹军马场植被的地上生物量。主要方法是在GPS的帮助下,通过野外实地采样,然后根据样点数据和NDVI、第一主成分、DVI、TM4通道的光谱反射率数据之间的线性相关性,并利用逐步回归方法建立了估算生物量的最优模型,用此模型计算了山丹军马场典型区的生物量。     

马加爵犯罪心理结构解析——兼议在大学生思想工作中引进宣泄理论和目标引导

马加爵一案不是简单的“激情杀人”或“变态杀人”。其犯罪心理结构的浅表因素为性格偏狭、情绪反应过度；基础因素则为性格内向、情绪压抑过度；核心因素为无力性格即生活目标缺失。对马加爵犯罪心理结构的解析有助于对大学生特别是大学贫困生的了解，对大学教育进行准确定位，在思想工作中引起宣泄理论及目标引导等。     

Further study of sources of the imported cobalt-blue pigment used on Jingdezhen porcelain from late 13 to early 15 centuries

Based on the conclusion of modern scientific analysis: the cobalt-blue pigment applied on Jingdezhen official porcelain during Yuan Dynasty and prior to Xuande reign of Ming Dynasty (1271–1425) contains high iron and low manganese contents, and the cobalt during Xuande and after Xuande periods (after 1426) of Ming Dynasty contains high manganese and low iron contents, in combination with the traditional archaeological method, the related historical textual records were investigated and analyzed, the imported cobalt employed on Jingdezhen official porcelain was studied comprehensively, systematically and logically. In fact, ‘Su Ma Li Qing’ (Samarra-blue) and ‘Su Bo Ni Qing’ (Sumatra-blue) are definitely different cobalt ores originated in different places, because of their very similar transliterations in Chinese, the confusion has appeared in ancient books for more than 400 years, which considered ‘Su Ma Li Qing’ and ‘Su Bo Ni Qing’ as the same cobalt-blue pigment. In this article the mistake was corrected, the possible producing places and the approximate eras of the two pigments imported to China and used at Jingdezhen were also suggested.     

Towards better 3-D reconstructions by combining electron tomography and atom-probe tomography

Scanning transmission electron microscope tomography and atom-probe tomography are both three-dimensional techniques on the nanoscale. We demonstrate here the combination of the techniques by analyzing the very same volume of an Al-Ag alloy specimen. This comparison allows us to directly visualize the theoretically known artifacts of each technique experimentally, providing insight into the optimal parameters to use for reconstructions and assessing the quality of each reconstruction. The combination of the techniques for accurate morphology and compositional information in three dimensions at the nanoscale provides a route for a new level of materials characterization and understanding.     

马祖芹壁传统聚落研究——兼论马祖民居的建筑特色

本文根据作者的实地考察及相关史料,论述了马祖芹壁传统聚落的历史沿革、兴衰过程,以及保护与利用的现状,并对今后的发展提出了几点建议。同时还兼述了马祖民居的一些建筑特色。