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101.
The identification of painting techniques is an important aspect of any research related to historical, artistic, and conservation issues in the field of wall paintings conservation. There are a variety of different methodological approaches that can be used to identify wall painting techniques. In this study, the application of optical (PLM) and electron (SEM-EDX) microscopy was explored as they are complementary analytical techniques commonly used for micro-stratigraphic analysis of painted surfaces. Five replicas were prepared according to the technical procedures reported in medieval historical treatises, and the pigment was applied at different time intervals in order to monitor the modifications at the interface between the ground and pictorial layer. The comparison of data from the replicas with samples from Romanesque wall paintings in churches in Southern Switzerland and Northern Lombardy (Italy) allowed for an evaluation of the reliability of the proposed methodology and for the interpretation of the painting techniques.  相似文献   
102.
论述了在大气状态下扫描隧道显微镜STM在石墨表面上的电场加工实验,并对作用机理进行了分析,认为表面结构的生成是场蒸发效应和化学反应(局部气化反应)的综合作用。  相似文献   
103.
INTRODUCTIONThemicrostructureofthinfilmsplaysacru cialroleinawidevarietyofphysicalprocesses.Thereareclearevidencesthatmanyphysicalpropertiesofathinfilmvarydramaticallyasitsmicrostructurechanges (Hausetal.,1 987) .Forinstance,roughsubstratescanbeusedtofabric…  相似文献   
104.
本文研究原子间的线性和非线性相互作用对两个原子玻色爱因斯坦凝聚(BEC)系统中的隧穿动力学的影响.这两个BEC初始处于相干态.我们详细研究了这类隧穿动力学的短时间(在凝聚的相干时间内)行为.发现由原子隧穿导致的两个凝聚间的布居差表现出周期性的拉比振荡,其振荡周期不仅依赖于原子间的相互作用,还取决于系统的初态.我们表明在一定条件下此系统可达到一个自囚禁的稳态.我们还研究了两个凝系间的隧穿原子流,发现在一定条件下可获得一个只含纯直流的原子流.  相似文献   
105.
In this paper,environmental scanning electron microscopy (ESEM) is applied to characterizing the mineral and element distribution of chromite ore processing residue (COPR).The test results show that Cr-bearing brownmillerite occurs in the rim of COPR particle,while hydroandradite with Cr(Ⅵ) in its structure presents inside the COPR particle.Periclase and calcite occur in the interstitial area.Element analyses show that Ca,Fe and Al are distributed throughout the COPR particle,and Mg exists mostly in the interstitial area or on the particle surface.A lower content of Cr is evenly distributed in the COPR particle,while slightly higher concentration of Cr occurs inside the particle.It is suggested that it will take a relatively longer time for Cr to migrate out of COPR,especially for hexavalent chromium,so the leaching time and the particle size may be two important factors to affect the release of Cr(Ⅵ).  相似文献   
106.
在现行法律制度环境下,民办高校控制权私利是民办高校举办者和创办者获取投资回报的主要途径和方式。通过实际案例研究表明:民办高校举办者和创办者在学校不同发展阶段中获取控制权私利的途径和方式有所不同,主要有:法人财产虚置、转移现金、转移利润、转移资产和转让控制权等。  相似文献   
107.
利用时谐电磁场理论和时域有限差分数值方法分析了亚波长金属扫描探针电磁场模式的场型结构和空间分布及透射特性等主要的传输性质,导出了亚波长金属探针内球横电模和球横磁模各电磁场分量的解析表达,运用数值求解获得的精确本征值,得到了金属探针内几个低阶模在球横截面内的场型结构.时域有限差分数值模拟研究结果表明,时谐电磁场的空间分布在亚波长金属探针内呈现准周期性振荡变化,并且在传输径向坐标上会出现一个最大值,最大值的位置随光波波长发生改变,研究结果还表明,在亚波长探针内刻蚀可以更好地激发和引导表面等离子体激元波到达出射孔径端口,提高亚波长空心锥的透射率和增强光学仪器的空间分辨率.  相似文献   
108.
This dissertation intends to show a theoretical framework and a practical teaching plan of how a three-stage reading instruction works for developing efficient readers in middle school reading classroom.  相似文献   
109.
The adoption of virtual microscopy at the University of Turku, Finland, created a unique real‐world laboratory for exploring ways of reforming the learning environment. The purpose of this study was to evaluate the students' reactions and the impact of a set of measures designed to boost an experimental group's understanding of abnormal histology through an emphasis on knowledge of normal cells and tissues. The set of measures included (1) digital resources to review normal structures and an entrance examination for enforcement, (2) digital course slides highlighting normal and abnormal tissues, and (3) self‐diagnostic quizzes. The performance of historical controls was used as a baseline, as previous students had never been exposed to the above‐mentioned measures. The students' understanding of normal histology was assessed in the beginning of the module to determine the impact of the first set of measures, whereas that of abnormal histology was assessed at the end of the module to determine the impact of the whole set of measures. The students' reactions to the instructional measures were assessed by course evaluation data. Additionally, four students were interviewed. Results confirmed that the experimental group significantly outperformed the historical controls in understanding normal histology. The students held favorable opinions on the idea of emphasizing normal structures. However, with regards to abnormal histology, the historical controls outperformed the experimental group. In conclusion, allowing students access to high‐quality digitized materials and boosting prerequisite skills are clearly not sufficient to boost final competence. Instead, the solution may lie in making students externally accountable for their learning throughout their training. Anat Sci Educ 6: 73–80. © 2012 American Association of Anatomists.  相似文献   
110.
Remote access technologies enable students to investigate science by utilizing scientific tools and communicating in real-time with scientists and researchers with only a computer and an Internet connection. Very little is known about student perceptions of how real remote investigations are and how immersed the students are in the experience. This study, conducted with high school students and their teachers, explored the impact of students' perception of ownership and virtual presence during a remote investigation using a scanning electron microscope. Students were randomly assigned to one of two treatment groups: students able to select their own insect to use during the remote investigation, and students that did not select their own insects to view during the remote investigation. The results of this study showed that students in the experimental group who had choice and ownership of their insect reported being more present (less distracted) during the remote investigation than students in the control group, whereas students in the control group reported controlling the technology was easier than the experimental group. Students indicated the remote investigation was very real; however, the teachers of these students were less likely to describe the investigation as being real. The results of this study have practical implications for designing remote learning environments.  相似文献   
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