A reverse condition of accretion flow and its constraints on black hole spin in the quasi-cycle are proposed.It is shown that the necessary condition for the quasi-cycle is that the closed magnetic field lines must do...A reverse condition of accretion flow and its constraints on black hole spin in the quasi-cycle are proposed.It is shown that the necessary condition for the quasi-cycle is that the closed magnetic field lines must dominate over the open ones at the horizon.The efficiency of converting accreted rest mass into radiation energy in the quasi-cycle is proved to increase as the strength of the magnetic transfer process.In addition,a general expression for the efficiency is derived.展开更多
Some interesting behaviour of accreting particles in the gap region between the horizon of the Kerr black hole and the inner edge of the surrounding disc is investigated.The following results are obtained:(i)Spacetime...Some interesting behaviour of accreting particles in the gap region between the horizon of the Kerr black hole and the inner edge of the surrounding disc is investigated.The following results are obtained:(i)Spacetime coincidence of the maximum of angular velocity of accreting particles and that of the black hole horizon is extended to the more general disc-accretion.(ii)The Possibilities is discussed of negative energy of accreting particles in prograde orbit inside the ergosphere of the Kerr black hole,which is surrounded by strong enough magnetic field.展开更多
Evolution of black hole(BH)accretion disks is investigated by a new approach,in which the evolution of the central BH can be derived in terms of BH spin directly,and the evolution characteristics of the concerning BH ...Evolution of black hole(BH)accretion disks is investigated by a new approach,in which the evolution of the central BH can be derived in terms of BH spin directly,and the evolution characteristics of the concerning BH parameters are shown more easily and obviously.As an example,the unusual evolution characteristics of angular velocity of BH horizon and that of accreting particles at the inner edge of the disk are derived by considering the Blandford-Znajek process.展开更多
The evolution characteristics and energy extraction of a rotating black hole are investigated by considering magnetic coupling with the surrounding accretion disc.It is found that both mass and spin of the black hole ...The evolution characteristics and energy extraction of a rotating black hole are investigated by considering magnetic coupling with the surrounding accretion disc.It is found that both mass and spin of the black hole might be reduced by the joint effects of disc accretion and magnetic coupling,provided that the latter is stronger than the former.The efficiencies of the two energy mechanisms are calculated and compared to a variety of parameters.In addition,the validity of the laws of black hole thermodynamics is discussed.展开更多
文摘本试验旨在研究脂多糖(LPS)刺激对猪肠上皮细胞系(IPEC1)细胞活力、乳酸脱氢酶(LDH)活性、紧密连接蛋白和炎症相关基因表达的影响。分别选取0、0.025、1、10μg/m L的LPS刺激细胞1、2、4、8 h,检测相关指标。结果表明:在不同时间,不同浓度的LPS对细胞活力的影响未呈现出显著的规律性;与0、0.025μg/m L LPS组相比,在1、4、8h,1、10μg/mLLPS处理导致IPEC1上清液LDH活性显著升高;在不同时间,不同浓度的LPS对紧密连接蛋白(ZO-1、occludin、claudin-1)和炎症相关基因(TLR4、NF-κB、TNF-α和IL-6)mRNA表达影响未呈现出显著的规律性。以上结果表明,LPS刺激能引起IPEC1细胞损伤,但不能诱导显著的炎症反应。
基金Supported by the National Natural Science Foundation of China under Grant No.19773005.
文摘A reverse condition of accretion flow and its constraints on black hole spin in the quasi-cycle are proposed.It is shown that the necessary condition for the quasi-cycle is that the closed magnetic field lines must dominate over the open ones at the horizon.The efficiency of converting accreted rest mass into radiation energy in the quasi-cycle is proved to increase as the strength of the magnetic transfer process.In addition,a general expression for the efficiency is derived.
基金Supported by the National Natural Science Foundation of China under Grant No.19773005.
文摘Some interesting behaviour of accreting particles in the gap region between the horizon of the Kerr black hole and the inner edge of the surrounding disc is investigated.The following results are obtained:(i)Spacetime coincidence of the maximum of angular velocity of accreting particles and that of the black hole horizon is extended to the more general disc-accretion.(ii)The Possibilities is discussed of negative energy of accreting particles in prograde orbit inside the ergosphere of the Kerr black hole,which is surrounded by strong enough magnetic field.
基金Supported by the National Natural Science Foundation of China under Grant No.19773005.
文摘Evolution of black hole(BH)accretion disks is investigated by a new approach,in which the evolution of the central BH can be derived in terms of BH spin directly,and the evolution characteristics of the concerning BH parameters are shown more easily and obviously.As an example,the unusual evolution characteristics of angular velocity of BH horizon and that of accreting particles at the inner edge of the disk are derived by considering the Blandford-Znajek process.
基金Supported by the National Natural Science Foundation of China under Grant No.19773005.
文摘The evolution characteristics and energy extraction of a rotating black hole are investigated by considering magnetic coupling with the surrounding accretion disc.It is found that both mass and spin of the black hole might be reduced by the joint effects of disc accretion and magnetic coupling,provided that the latter is stronger than the former.The efficiencies of the two energy mechanisms are calculated and compared to a variety of parameters.In addition,the validity of the laws of black hole thermodynamics is discussed.
