稀土掺杂氧卤玻璃光谱性质研究（英文）

本研究主要目的在于探索适用于宽带光纤放大器和蓝绿光激光器用稀土掺杂基质玻璃材料。通过对掺Er3+重金属氧氟玻璃的光谱性质和析晶稳定性研究以及稀土离子掺杂重金属氧卤玻璃的上转换发光研究,为其在宽带掺Er3+光纤放大器和蓝绿光波段激光器中的潜在应用提供基础。研究结果表明：重金属PbF2的加入提高了掺Er3+硅酸盐玻璃和锗酸盐玻璃的带宽特性和增益性能;首次在Er3+/Yb3+共掺和Er3+单掺硅酸盐玻璃发现上转换蓝光;重金属氟化铅的加入提高了Er3+单掺锗酸盐和碲酸盐玻璃的上转换发光;在室温下同时观察到Er3+的上转换蓝光、绿光和红光,分别是由于Er3+离子2H9/2→4I15/2, 2H11/2→4I15/2, 4S3/2→4I15/2, 和4F9/2→4I15/2跃迁;混合卤化铅效应调整Tm3+/Yb3+共掺碲酸盐有利于基质玻璃析晶性能的改善和上转换发光性能的提高;在室温下同时观察到Tm3+的上转换蓝光和红光,分别是由于Tm3+离子的1G4→3H6和1G4→3H4跃迁;首次在碲酸盐基质玻璃中发现OH-吸收对Er3+和Tm3+的上转换发光具有重要影响。     

鄂尔多斯盆地镇北地区延长组长7沉积期物源分析

收集前人研究成果,结合薄片鉴定、重矿物分析、稀土元素及地震等资料,对鄂尔多斯盆地延长组长7沉积期物源进行分析.结果表明：镇北地区延长组长7物源来自盆地西部和西南方向,其中西南物源为主要物源区,主要岩性为变质岩、中酸性岩浆岩;西部方向仅为沉积区提供白云岩等碳酸盐岩碎屑.     

Re-Discovering a Roman Wall Painting at Harvard: New Research on a Fragment from the Villa at Boscotrecase

ABSTRACT

This article presents historical and scientific analysis, as well as the conservation treatment of a newly rediscovered Roman wall painting fragment, now in the collection of the Harvard Art Museums. Although the piece has not previously been published, it was among a group of fragments removed from a Roman villa near Boscotrecase in southern Italy, an area that has been key to the study of Roman wall painting and other decoration. Technical imaging confirms the use of painting techniques consistent with other high-quality paintings in the area. Materials analysis revealed a palette consistent with published findings of Roman wall paintings, including abundant use of Egyptian blue and green earth. Of interest was the use of Egyptian blue as an optical brightener in select white passages. Despite the high quality of the painting, no cinnabar was present, and all red passages were achieved using hematite. Multiple different white minerals were identified including calcite, aragonite, and gypsum. The widespread presence of gypsum is unusual and may point to alteration.     

Google Earth在《遥感原理与方法》教学中的应用

Google Earth作为一门新技术,在多种领域中得到广泛应用.介绍了在《遥感原理与方法》课程教学过程中,Google Earth在影像的直观性、遥感影像的大气校正、遥感影像的几何校正、遥感影像的像点位移以及遥感应用等方面的作用.教学结果表明,Google Earth能够激发学生的学习兴趣,提高教学效果.     

Single-phase earth fault current distribution between optical fiber composite overhead ground wire and ordinary ground wire in transmission system

It is important for the safety of transmission system to accurately calculate single-phase earth fault current distribution. Features of double sided elimination method were illustrated. Quantitative calculation of single-phase earth fault current distribution and case verification were accomplished by using the loop method. Influences of some factors, such as single-phase earth fault location and ground resistance of poles, on short-circuit current distribution were discussed. Results show that: 1) results of the loop method conform to those of double sided elimination method; 2) the fault location hardly influences macro-distribution of short-circuit current. However, current near fault location is evidently influenced; and 3) the short-circuit current distribution is not so sensitive to the ground resistance of poles.     

论李宗仁“焦土抗战”新哲理及其作用

通过李宗仁在“焦土抗战论”中对时局的特点、对日和抗日国策、总体战略战术原则的分析和论述,认为李宗仁具有朴素的唯物主义世界观和辩证法军事思想,其哲理性具有新世界观萌芽的性质。这些新哲理为世界反法西斯战争的中国战场提供先进思想武器,并发挥着积极的能动作用。     

软土地区路基扩建工程变形监测分析

以某湖区公路路基拓宽工程为依托,建立沉降、位移监测体系,通过长时间的数据监测结果,分析了新老路基不协调变形的发展规律,为类似湖区公路路基拓宽工程的施工提供指导。     

浅谈如何在工程变更中分析合同条款强化变更管理

针对H航市政工程仔细研究合同,找准突破口,把变更方向确定为通过各类措施增加土方工程量和尽量争取合同内专业分包转为项目部实施为目标。     

双参数地基上土钉墙面层土压力计算

土钉墙面层承受部分土(水)压力,文中把土钉墙面层看作是弹性地基上的有限长梁,在试验的基础上,推导了基于双参数地基的成层土层分布的土钉墙面层在土钉拉力作用下的挠曲线、转角、弯矩和剪力方程,并与实测数据进行了比较分析,验证了模型的合理性,得到的解析解基本上可以反映土钉墙面层土压力的分布.在此基础上,探讨了不同土性土层中土钉墙面层土压力的分布.面层土压力在土层的分界面上位移连续土压力突变;作用在软弱土层的面层土压力比硬土层上的面层土压力大;上软下硬型较上硬下软的土层分布更能使面层土压力得到充分发挥;同时文中计算了面层土压力换算成荷载与土钉拉力的比值,面层对于土压力的作用随着深度的增加表现得愈加明显,提出针对不同地区不同深度和不同土性条件下应给出比值的建议值,以使土钉墙的设计更符合其真实的作用机理.文中得到的结论和计算方法对于进一步研究土钉墙的作用机理及设计中如何充分发挥面层的作用等具有重要的理论意义和实际应用价值.     

水土计算原则及浅埋结构土压力计算理论分析

基于现有规范、理论和工程经验,对地下结构中的水土计算原则和浅深埋界限的确定方法进行了归纳分析,给出了浅埋地下结构竖向土压力计算的3种理论,即土柱理论、比尔鲍曼理论和谢家理论,并对三个理论在规范计算方法中的应用进行了深入讨论,系统给出了浅埋地下结构土层压力计算方法。