想念漫游 - 王贰浪

The use of time--like geodesics to measure temporal distances is better justified than the use of space--like geodesics for a measurement of spatial distances. We give examples where a ''spatial distance'' cannot be appropriately determined by the length of a space--like geodesic.

The Bures distance between two displaced thermal states and the corresponding geometric quantities (statistical metric, volume element, scalar curvature) are computed. Under nonunitary (dissipative) dynamics, the statistical distance shows the same general features previously reported in the literature by Braunstein and Milburn for two--state systems. The scalar curvature turns out to have new interesting properties when compared to the curvature associated with squeezed thermal states.

在经济快速发展的大环境下,转型升级已经成为各行业发展的主要趋势,高速公路运输自然也不例外。高速公路运输经济的转型升级不仅能够为我国交通体系的构建提供帮助,还能为我国经济水平的提高以及文化交流带来较大的动力。不过针对高速公路运输经济转型中存在的问题,相关工作人员有必要加大研究力度,以寻找有效的解决方式,加快转型,促进经济增长。

I report on recent studies of hadronic physics performed by the BaBar Collaboration. Emphasis is given to the measurement of the properties of newly discovered charmed hadrons and to the searches for light and heavy pentaquarks.