We present a new method to identify the critical point for the Bose-Einstein condensation （BEC） of a trapped Bose gas. We calculate the momentum distribution of an interacting Bose gas near the critical temperature,...We present a new method to identify the critical point for the Bose-Einstein condensation （BEC） of a trapped Bose gas. We calculate the momentum distribution of an interacting Bose gas near the critical temperature, and find that it deviates significantly from the Gaussian profile as the temperature approaches the critical point. More importantly, the standard deviation between the calculated momentum spectrum and the Gaussian profile at the same temperature shows a turning point at the critical point, which can be used to determine the critical temperature. These predictions are also confirmed by our BEC experiment for magnetically trapped ST Rb gases.展开更多
Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under...Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under a complete information level, the physic approach, that is, observing its component lifetime. We intend to optimize system reliability under standby redundancy allocation of its components, particularly, under minimal standby redundancy. To get results, we will use a coherent system representation through a signature point process.展开更多
The advent of low loss optical fiber has consistently led us to the ultra-broadband era, where bandwidths exceeding 1 Gb/s are commonplace. This Review reviews the early history of fiber access, pointing out some of t...The advent of low loss optical fiber has consistently led us to the ultra-broadband era, where bandwidths exceeding 1 Gb/s are commonplace. This Review reviews the early history of fiber access, pointing out some of the lasting design choices and signature features of fiber access. The progress of the various passive optical network technologies is also reviewed, and some views regarding the future trends of fiber in the access.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11104322the National Key Basic Research and Development Program of China under Grant No 2011CB921503
文摘We present a new method to identify the critical point for the Bose-Einstein condensation （BEC） of a trapped Bose gas. We calculate the momentum distribution of an interacting Bose gas near the critical temperature, and find that it deviates significantly from the Gaussian profile as the temperature approaches the critical point. More importantly, the standard deviation between the calculated momentum spectrum and the Gaussian profile at the same temperature shows a turning point at the critical point, which can be used to determine the critical temperature. These predictions are also confirmed by our BEC experiment for magnetically trapped ST Rb gases.
文摘Willing to work in reliability theory in a general set up, under stochastically dependence conditions, we intend to characterize a not identically spare standby redundancy operation through compensator transform under a complete information level, the physic approach, that is, observing its component lifetime. We intend to optimize system reliability under standby redundancy allocation of its components, particularly, under minimal standby redundancy. To get results, we will use a coherent system representation through a signature point process.
文摘The advent of low loss optical fiber has consistently led us to the ultra-broadband era, where bandwidths exceeding 1 Gb/s are commonplace. This Review reviews the early history of fiber access, pointing out some of the lasting design choices and signature features of fiber access. The progress of the various passive optical network technologies is also reviewed, and some views regarding the future trends of fiber in the access.
