We present the results of the spectral fits made to 59 Rossi X-ray Timing Explorer （RXTE） observations of the Galactic X-Ray Black-Hole Candidate XTE J1650–500 covering the first 30d of its 2001/2002 outburst when ...We present the results of the spectral fits made to 59 Rossi X-ray Timing Explorer （RXTE） observations of the Galactic X-Ray Black-Hole Candidate XTE J1650–500 covering the first 30d of its 2001/2002 outburst when the source was in a transition from the hard state to the soft state. The photon spectra can be well fit- ted with a phenomenological model of a power-law/cutoff power-law and a physical model of bulk-motion Comptonization. The spectral properties smoothly evolve away from the hard state and then stay in the soft state. The fitting results of the physical model reveal the peak of the burst had a flux of 2.90 × 10-8 erg cm-2 s-1 in the 2–100 keV energy range and was observed on 2001 Sep. 9; it transitioned to the hard state. The total flux decays by a factor of ～3 as it evolves into the soft state. The photon index Γ increases from ～1.5 in the hard state and stays at ～2.5 in the soft state. We found that the effective area of the high-energy X-ray emission region （the Compton cloud） decreases, i.e. the area of the Compton cloud decreases by a factor of ～23 during the transition from the hard state to the soft state. Combining the new radio and quasi-periodic oscillation studies, the model of total flux in the 2–100 keV energy range, the jet emission and the timing analysis during the state transition, we suggest a possible geometry and evolution for the （jet＋corona＋disk） system, like that proposed by Kalemci et al. based on enhanced lags and peak frequency shift during the transition.展开更多
推荐机制是分布式目录服务系统中一个十分重要的功能 ,它的构成和使用都充分体现了分布式目录服务的特征 .本文简要介绍了 L DAPv3中与实现推荐机制紧密相关的“referral”对象类和“ref”属性 ,仔细分析了 L DAPv3协议中服务器端和客...推荐机制是分布式目录服务系统中一个十分重要的功能 ,它的构成和使用都充分体现了分布式目录服务的特征 .本文简要介绍了 L DAPv3中与实现推荐机制紧密相关的“referral”对象类和“ref”属性 ,仔细分析了 L DAPv3协议中服务器端和客户端对推荐的使用及处理 ,提出了在基于 L DAPv3的目录服务系统中推荐机制的设计与实现方案 .在实际系统实现中取得了较好的分布式操作效果 .展开更多
基金partially supported by the Grant-in-Aid for Scientific Research on Priority Areas (Grant No. 14079101)financial supports from the National Natural Science Foundation of China (Grant No. 10778702)+1 种基金the National Basic Research Program of China (973 Program, Grant No. 2009CB824800)the Policy Research Program of Chinese Academy of Sciences (KJCX2-YWT24)
文摘We present the results of the spectral fits made to 59 Rossi X-ray Timing Explorer （RXTE） observations of the Galactic X-Ray Black-Hole Candidate XTE J1650–500 covering the first 30d of its 2001/2002 outburst when the source was in a transition from the hard state to the soft state. The photon spectra can be well fit- ted with a phenomenological model of a power-law/cutoff power-law and a physical model of bulk-motion Comptonization. The spectral properties smoothly evolve away from the hard state and then stay in the soft state. The fitting results of the physical model reveal the peak of the burst had a flux of 2.90 × 10-8 erg cm-2 s-1 in the 2–100 keV energy range and was observed on 2001 Sep. 9; it transitioned to the hard state. The total flux decays by a factor of ～3 as it evolves into the soft state. The photon index Γ increases from ～1.5 in the hard state and stays at ～2.5 in the soft state. We found that the effective area of the high-energy X-ray emission region （the Compton cloud） decreases, i.e. the area of the Compton cloud decreases by a factor of ～23 during the transition from the hard state to the soft state. Combining the new radio and quasi-periodic oscillation studies, the model of total flux in the 2–100 keV energy range, the jet emission and the timing analysis during the state transition, we suggest a possible geometry and evolution for the （jet＋corona＋disk） system, like that proposed by Kalemci et al. based on enhanced lags and peak frequency shift during the transition.
文摘推荐机制是分布式目录服务系统中一个十分重要的功能 ,它的构成和使用都充分体现了分布式目录服务的特征 .本文简要介绍了 L DAPv3中与实现推荐机制紧密相关的“referral”对象类和“ref”属性 ,仔细分析了 L DAPv3协议中服务器端和客户端对推荐的使用及处理 ,提出了在基于 L DAPv3的目录服务系统中推荐机制的设计与实现方案 .在实际系统实现中取得了较好的分布式操作效果 .
