Quantum Nonthermal Radiation of the Nonstationary Kerr-Newman Black Hole

Quantum nonthermal radiation of a nonstationaryKerr-Newman black hole is studied by using theHamilton-Jacobi equation and generalized tortoisecoordinates. It is shown that the positive energy stateinterlaces with the negative state in a region near theevent horizon, and spontaneous quantum nonthermalradiation takes place in the overlap region.     

The quantum nonthermal effect of a nonstationary Kerr－Newman black hole and the average range of the effective particles

We have found that the nonthermal radiation of a nonstationary Kerr－Newman black hole is affected by interstellar materials. In particular, the interstellar gas deeply influences the average range of nonthermal radiation particles, while the average range depends on the maximum energy of the radiation and the energy extent of the radiation.     

Nonthermal radiation from nonstationary Kerr black hole

A crossing of the positive and negative Dirac energy levels occurs near a nonstationary Kerr black hole. The maximum value of the energy of a particle in the nonthermal radiation depends not only on the dragging velocity, but also the evaporation rate and the event horizon shape of the black hole.     

Quantum nonthermal effect of the Vaidya-Bonner-de Sitter black hole

Using the Hamilton-Jacobi equation of a scalar particle in the curve space-time and a correct- dimension new tortoise coordinate transformation, the quantum nonthermal radiation of the Vaidya-Bonner-de Sitter black hole is investigated. The energy condition for the occurrence of the Starobinsky-Unruh process is obtained. The event horizon surface gravity and the Hawking temperature on the event horizon are also given.     

Nonthermal radiation of rotating black holes

The nonthermal radiation of a Kerr black hole is considered as the tunneling of particles being produced through an effective Dirac gap. In the leading semiclassical approximation, this approach is also applicable to bosons. Our semiclassical results for photons and gravitons are consistent with those obtained previously. For neutrinos, the result of our complete quantum-mechanical calculation is about twice as large as the previous one.     

银河系中心超大质量黑洞

通过对位于银河系中心的非热、致密射电源人马座A^＊（Sagittarius A^＊）的高分辨率甚长基线干涉（VLBI）观测,文章作者及其合作者成功地得到人马座A＊的固有辐射区域的直径仅为1个天文单位,支持其是超大质量黑洞的物理解释.文章在较详细地介绍此研究的同时,也简要提及了从黑洞概念的最早提出至今的200多年里人们在黑洞物理认知上的一些重大进展.可以预期,未来亚毫米波VLBI观测将有望揭示银河系中心超大质量黑洞的阴影结构.     

Hawking effect and quantum nonthermal radiation of an arbitrarily accelerating charged black hole using a new tortoise coordinate transformation

Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour-Ruffini method. After the tortoise coordinate transformation, the Klein-Gordon equation can be written as the standard form at the event horizon. Then extending the outgoing wave from outside to inside of the horizon analytically, the surface gravity and Hawking temperature can be obtained automatically. It is found that the Hawking temperatures of different points on the surface are different. The quantum nonthermal radiation characteristics of a black hole near the event horizon is also discussed by studying the Hamilton-Jacobi equation in curved spacetime and the maximum overlap of the positive and negative energy levels near the event horizon is given. There is a dimensional problem in the standard tortoise coordinate and the present results may be more reasonable.     

Black hole emissions and phase transitions

The nonthermal emission of a rotating black hole is related to the inner horizon of the hole. The transition from the Kerr black hole state to the naked singularity state is considered as a phase transition. An arrangement of the energetics of Kerr black holes into a two-phase thermodynamics is suggested.     

The quantum nonthermal radiation and horizon surface gravity of an arbitrarily accelerating black hole with electric charge and magnetic charge

Using a new tortoise coordinate transformation,we discuss the quantum nonthermal radiation characteristics near an event horizon by studying the Hamilton-Jacobi equation of a scalar particle in curved space-time,and obtain the event horizon surface gravity and the Hawking temperature on that event horizon.The results show that there is a crossing of particle energy near the event horizon.We derive the maximum overlap of the positive and negative energy levels.It is also found that the Hawking temperature of a black hole depends not only on the time,but also on the angle.There is a problem of dimension in the usual tortoise coordinate,so the present results obtained by using a correct-dimension new tortoise coordinate transformation may be more reasonable.     

Quantum nonthermal radiation and horizon surface gravity of an arbitrarily accelerating black hole with electric charge and magnetic charge

With a new tortoise coordinate transformation, we discussed the quantum nonthermal radiation characteristics near the event horizon by studying the Hamilton-Jacobi equation of a scalar particle in the curve space-time, and obtained the event horizon surface gravity and the Hawking temperature on the event horizon. The results showed that there is a crossing of particle energy near the event horizon. We derived the maximum overlap of the positive and negative energy levels. It was also found that the Hawking temperature of a black hole depends on not only the time, but also the angle. There is a problem of dimension in the usual tortoise coordinate, so the present results obtained by using a correct-dimension new tortoise coordinate transformation may be more reasonable.     

Radiation characteristics of multiple and single sound hole vihuelas and a classical guitar

Two recently built vihuelas, quasi-replicas of the Spanish Renaissance guitar, one with a small body and one sound hole and one with a large body with five sound holes, together with a classical guitar are investigated. Frequency dependent radiation strengths are measured using a 128 microphone array, back-propagating the frequency dependent sound field upon the body surface. All three instruments have a strong sound hole radiation within the low frequency range. Here the five tone holes vihuela has a much wider frequency region of strong sound hole radiation up to about 500 Hz, whereas the single hole instruments only have strong sound hole radiations up to about 300 Hz due to the enlarged radiation area of the sound holes. The strong broadband radiation of the five sound hole vihuela up to about 500 Hz is also caused by the sound hole phases, showing very consistent in-phase relations up to this frequency range. Also the radiation strength of the sound holes placed nearer to the center of the sound box are much stronger than those near the ribs, pointing to a strong position dependency of sound hole to radiation strength. The Helmholtz resonance frequency of the five sound hole vihuela is influenced by this difference in radiation strength but not by the rosettas, which only have a slight effect on the Helmholtz frequency.     

激光腔靶辐射时间特性研究

介绍了激光加热腔靶辐射时间特性研究。实验采用滤长为１．０５３μｍ，能量为３０－７５０Ｊ，脉宽为６００－１１００ｐｓ的高斯型激光脉冲，辐照柱型腔靶，用两台具有一定和时间分辨的亚千Ｘ射线能谱仪，分别观察激光入射口和Ｘ光输运口的辐射时间特性，实验结果给出了腔靶源区发射Ｘ光时间过程及其与发射口面积，形状，发射能区等的关系。     

Collision of two rotating Hayward black holes

We investigate the spin interaction and the gravitational radiation thermally allowed in a head-on collision of two rotating Hayward black holes. The Hayward black hole is a regular black hole in a modified Einstein equation, and hence it can be an appropriate model to describe the extent to which the regularity effect in the near-horizon region affects the interaction and the radiation. If one black hole is assumed to be considerably smaller than the other, the potential of the spin interaction can be analytically obtained and is dependent on the alignment of angular momenta of the black holes. For the collision of massive black holes, the gravitational radiation is numerically obtained as the upper bound by using the laws of thermodynamics. The effect of the Hayward black hole tends to increase the radiation energy, but we can limit the effect by comparing the radiation energy with the gravitational waves GW150914 and GW151226.     

High-energy radiation from old pulsars

In this paper, we study nonthermal high energy radiation from old rotation-powered pulsars with ages greater than 10⁶ yr based on the revised outer gap model. In this model, the inclination angle and geometry of the magnetic field have been taken into account, and the fractional size f of the outer gap is determined by the electron/positron pair production process. The cascade process caused by the back-flowing particles moving from the outer gap to the star will produce the observed nonthermal X-ray emission, and the relativistic particles accelerated in the outer gap will produce gamma-rays via curvature radiation. For nine old pulsars which have been detected to have nonthermal X-rays, we first use the observed nonthermal X-ray emission to estimate reasonable inclination angles, and then estimate their gamma-ray emissions. We also study the possibilities of gamma-ray emissions from other old rotation-powered pulsars. We compare our predicted gamma-ray flux with the sensitivities of AGILE and Fermi.

     

Formation and evaporation of nonsingular black holes

Regular (nonsingular) space-times are given that describe the formation of a (locally defined) black hole from an initial vacuum region, its quiescence as a static region, and its subsequent evaporation to a vacuum region. The static region is Bardeen-like, supported by finite density and pressures, vanishing rapidly at large radius and behaving as a cosmological constant at small radius. The dynamic regions are Vaidya-like, with ingoing radiation of positive-energy flux during collapse and negative-energy flux during evaporation, the latter balanced by outgoing radiation of positive-energy flux and a surface pressure at a pair creation surface. The black hole consists of a compact space-time region of trapped surfaces, with inner and outer boundaries that join circularly as a single smooth trapping horizon.     

Quantum thermal effects of a radiating rotating charged black hole

Asymptotic solutions of the Klein-Gordon equation in a region near the event horizon of a radiating rotating charged black hole are obtained by using generalized tortoise coordinates. The location of the event horizon and the Hawking temperature of the black hole are given. Both the horizon and the temperature depend on the angle and time, due to radiation. However, they are independent of the angle if either rotation or radiation vanishes. The treatment encompasses as special cases the results on a number of well-known black holes.     

Black hole and hawking radiation by type-II Weyl fermions

The type-II Weyl and type-II Dirac fermions may emerge behind the event horizon of black holes. Correspondingly, the black hole can be simulated by creation of the region with overtilted Weyl or Dirac cones. The filling of the electronic states inside the “black hole” is accompanied by Hawking radiation. The Hawking temperature in the Weyl semimetals can reach the room temperature, if the black hole region is sufficiently small, and thus the effective gravity at the horizon is large.     

利用山形空穴存储层结构对深紫外激光二极管的性能优化

为了有效提高深紫外激光二极管的空穴注入效率和减少电子泄露,优化其性能,设计出了在基础矩形空穴存储层结构上改进后的山形空穴存储层和倒山形空穴存储层。使用Crosslight软件模拟仿真倒山形和山形空穴存储层结构的电子浓度、电子电流密度、能带图以及P-I特性曲线。结果显示山形空穴存储层激光器的光学和电学性能优于矩形和倒山形激光器,因此山形空穴存储层激光器能有效地增加有源区空穴注入和减少电子泄露,提高有源区载流子浓度和辐射复合速率,实现了激光器优越的光电性能。     

辐射加热腔诊断孔堵口特性实验研究

研究辐射加热腔诊断孔堵口现象。实验采用波长为１．０５３μｍ、能量为３００－４００Ｊ、脉宽为－８００ｐｓ的高斯型激光脉冲，双束对打具有双源区的腔靶。在激光入射口及内腔口服两台亚千电子伏特Ｘ射线能谱仪监测源区与内爆区发射的Ｘ光谱。定性分析和讨论了堵口现象。     

Generation of high-frequency phonons by defect-induced one-phonon absorption

By defect-induced one-phonon absorption of pulsed infrared radiation, we excited in diamond phonons at 28 THz. Their anharmonic decay leads to nonthermal frequency distributions of acoustic phonons which we investigated in a frequency range between 0.5 THz and 6 THz by use of vibronic sideband spectroscopy.