Broadband Vibrational Cooling of Cold Cesium Molecules： Theory and Experiments

The use of a broadband, frequency shaped femtosecond laser on translationally cold cesium molecules has recently demonstrated to be a very efficient method of cooling also the vibrational degree of freedom. A sample of cold molecules, initially distributed over several vibrational levels, has thus been transfered into a single selected vibrational level of the singlet X^1∑g ground electronic state. Our method is based on repeated optical pumping by laser light with a spectrum broad enough to excite all populated vibrational levels but limited in its frequency bandwidth with a spatial light modulator. In such a way we are able to eliminate transitions from the selected level, in which molecules accumulate. In this paper we briefly report the main experimental results and then address, in a detailed way by computer simulations, the perspectives for a ＂complete＂ cooling of the molecules, including also the rotational degree of freedom. Since the pumping process strongly depends on the relative shape of the ground and excited potential curves, ro-vibrational cooling through different excited states is theoretically compared.

ProTaperNext锉和WaveOne锉根管成形能力的对比研究

目的:比较机用ProTaperNext和WaveOne在弯曲树脂模拟根管中的成形能力。方法:选取统一规格的透明树脂模拟根管40个,将其随机分为2组,分别使用ProTaperNext和WaveOne锉以冠向下技术预备两组树脂模拟根管。使用ImagePro Plus软件测量根管弯曲半径和弯曲度的变化以及各测量点去除树脂量,计算树脂去除总量和两组器械的中心定位力,同时记录和分析根管工作长度的变化和器械变形、分离等参数。结果:两种器械预备根管时,均能保持较好的工作长度,不易发生器械分离,能够较好的维持根管原始走形,但在根尖段,WaveOne预备后的根管较易发生偏移。结论:ProTaperNext与WaveOne相比,在预备重度弯曲根管时具有良好的根管成形能力。

论新时代中国国际塑造力的提高

随着中国综合国力的增强,国际塑造力也不断提高。党的十八大以来,中国日益走近世界舞台中央,为优化国际关系、改善国际秩序、促进世界经济发展、创造人类美好未来,提供了中国方案,贡献了中国智慧和力量,成为发挥国际塑造力作用的重要角色。中国国际塑造力的提高具有重大意义,能够为我国建设发展赢取更有利的国际环境,能够更好彰显中国作为负责任大国的国家形象,能够为人类和平与发展事业做出更大贡献。中国国际塑造力相对于世界和平与发展的需要来说,相对于国际社会对中国的期待来说,还是很不够的,还应进一步提高。为此,还要更好地壮大国家实力,增强国际规制议置权,提升国际话语权,努力发挥引领时代的作用。