Polarization in early optical afterglows of gamma-ray bursts driven by precessing jets

Jet precessions are widely involved in astrophysical phenomena from galaxies to X-ray binaries and gamma-ray bursts (GRBs). Polarization presents a unique probe of the magnetic fields in GRB jets. The precession of GRBs relativistic jets will change the geometry within the observable emitting region of the jet, which can potentially affect the polarization of the afterglow. In this paper, we take into account jet precession to study the polarization evolution and corresponding light curves in GRB early optical afterglows with ordered and random magnetic field geometries. We find that the jet precession in long-lived engines can significantly reduce the polarization degree (PD) regardless of the magnetic field structure. The strongest PD attenuation is found when the line of sight is aligned with the precession axis. Our results show that jet precession can provide new insight into the low PD measured in the early optical afterglows of GRBs.Comment: 10 pages, 3 figures, 1 table, accepted for publication in Ap

Quantum thermal transistor based on the qubit-qutrit coupling

A quantum thermal transistor is designed by the strong coupling between one qubit and one qutrit which are in contact with three heat baths with different temperatures. The thermal behavior is analyzed based on the master equation by both the numerical and the approximately analytic methods. It is shown that the thermal transistor, as a three-terminal device, allows a weak modulation heat current (at the modulation terminal) to switch on/off and effectively modulate the heat current between the other two terminals. In particular, the weak modulation heat current can induce the strong heat current between the other two terminals with the multiple-region amplification of heat current. Furthermore, the heat currents are quite robust to the temperature (current) fluctuation at the lower-temperature terminal within certain range of temperature, so it can behave as a heat current stabilizer.Comment: 9 pages, 8 figure

高血压基底节区中少量出血早期手术治疗

Objective: To evaluate the efficacy of operative approach via lateral fissure  in hypertensive basal ganglia hemorrhage with bleeding volume 20～30ml during early period. Methods: A total of 33 patients with hypertensive basal ganglia hemorrhage underwent microsurgical treatment transsylvian-transinsular approach within 24 hours after stroke. All the patients had definite neurological dysfunction and the blooding volume 20～30ml. The remained hematoma volume after 24 hours, the efficacy after 2 weeks, and activity of Daily Living after 6 months were measured to be compared between the two groups. Results: 24 hours after operation, hematoma was evacuated  more than 90% in 27 cases, 70% in 3 cases. 2 weeks after surgical operation, 26 cases got remarkably effect and 5 cases turned better. Follow-up assessment according to the Activity of Daily Living (ADL) for 6 months revealed a good recovery of grade I in 8 cases, grade II in 17,grade III in 5, grade IV in 1. Conclusion: Microsurgical treatment transsylvian-transinsular approach has a significant therapeutic effect on hypertensive basal ganglia hemorrhage of 20～30ml hematoma cases with definite neurological dysfunction.目的 探讨中少量高血压基底节区出血经侧裂岛叶入路早期手术治疗的临床效果。 方法 回顾性总结分析2010年10月—2013年3月期间，出血量在20～30ml有明确神经功能障碍，早期经侧裂岛叶入路手术治疗的33例高血压基底节区出血患者的临床资料。观察手术24h后血肿清除情况，术后2周治疗效果及术后6个月日常生活能力评分情况。 结果 33例患者中血肿清除超过90% 27例（81.8%），血肿清除超过70% 3例（9.1%）。术后2周显效26例（78.8%）,好转5例（12.1%），2例患者较术前变化不明显。术后随访6个月，有2例患者因再出血死亡，其余患者按日常生活能力（ADL）评分：Ⅰ级8例，Ⅱ级17例，Ⅲ级5例，Ⅳ级1例。结论 症状明确的中少量高血压基底节区出血患者早期实施经侧裂岛叶入路手术治疗，能显著改善其预后