长焦距光学系统杂光系数测量的新方法及其理论分析

在分析现有杂光系数测量的基础上，提出了一种新的长焦距光学系统杂光系数测量的方法，并对这种方法进行了理论分析。     

黑匣子实验的设计与解答

本文设计了一种判断串并联谐振黑匣子实验,并给出了测试方案.通过测试的数据求出黑匣子内部元器件的参数值,并指出此方案在教学中的优势.     

Entropy Quantization from a Neutral Black String

Taking into account the Bekenstein-Hawking area law,based on the analysis of Zeng and Liu et al.that area spectrum is determined by the periodicity of an outgoing wave,we discuss on the quantization of entropy from a neutral black string.In addition,applying the adiabatic invariant quantity method proposed by Majhi and Vagenas,we further verify the entropy quantum of the neutral black string.As a result,two different methods show that the quantum of entropy is Δ S=2π,which is in agreement with Bekenstein's proposal.     

Area Spectrum of D-Dimensional Large Schwarzschild-AdS Black Hole from Asymptotic Quasinormal Modes

We investigate the area and entropy spectra of D-dimensional large Schwarzschild black holes. By utilizing the new physical interpretation of quasinormal mode frequency we find that a large Schwarzschild-AdS black hole has an equally spaced area spectrum and an equidistant entropy spectrum; both are dependent on the spacetime dimension.     

超陷光黑硅结构研究

研究了超陷光黑硅表面圆锥阵列结构的设计.将圆锥结构分为五层,利用等效媒质理论进行了参数设计.考虑了硅材料折射率随波长的变化,用严格耦合波理论对不同入射角,圆锥阵列结构高度以及占空比时的反射率进行了计算分析.发现,圆锥阵列超陷光结构的周期为135 nm,高度为480 nm时,在0°～60°入射角范围内,对波长为300～1...     

Area and Entropy Spectrum of Gauss-Bonnet Gravity in de Sitter Space-Times for Black Hole Event Horizon

In this paper, we use the modified Hod's treatment and the Kunstatter's method to study the horizon area spectrum and entropy spectrum in Gauss-Bonnet de-Sitter space-time, which is regarded as the natural generalization of Einstein gravity by including higher derivative correction terms to the original Einstein-Hilbert action. The horizon areas have some properties that are very different from the vacuum solutions obtained from the frame of Einstein gravity. With the new physical interpretation of quasinormal modes, the area/entropy spectrum for the event horizon for nearextremal Gauss-Bonnet de Sitter black holes are obtained. Meanwhile, we also extend the discussion of area/entropy quantization to the non-extremal black holes solutions.     

电化学制备薄黑硅抗反射膜

采用计算机控制电流密度按指数规律衰减对单晶硅进行电化学腐蚀,得到了折射率随薄膜厚度连续均匀变化的抗反射膜,即黑硅样品. 这种在制取上快速、经济和工艺非常简单的样品,不仅在较宽波段范围内反射率小于5%,且整个薄膜厚度不足1μm. 利用传输矩阵方法对黑硅样品的反射谱进行模拟,得到了理论与实验符合较好的结果. 关键词： 多孔硅 折射率 抗反射膜 黑硅     

光学系统杂光测量与计算程序间的联系

根据光学衍射成像理论,建立了黑斑法测量光学系统杂光的杂光系数解析式.该解析式包括了被测系统的结构参数和测试条件两部分.并编制了计算程序,将计算值和测量结果进行了比较,两者较为一致.     

Efficient Design of Directive Patch Antennas in Mobile Communications Using Metamaterials

An efficient approach for designing directive patch antennas using metamaterials is presented. Based on the left-handed-material (LHM) transmission line model, circuit elements L and C of the LHM equivalent circuit model are computed in terms of the prescribed desirable characteristics of directive patch antennas. Formulae to calculate the LHM design parameters from the circuit elements L and C are developed. Design examples for the GSM900 and GSM1800 frequency bands in mobile communications are performed to illustrate validation and efficiency of this design approach.     

Spin of the M87 Black Hole

Spin measurement of the 6.5 billion solar mass black hole in M87 from the Event Horizon Telescope image is the latest in a series that span a wide range in values, but that tend to share the feature of corotation between the accretion flow and black hole. The spin paradigm for black holes predicts very high black hole spin which in that framework is produced in its last significant merger. High black hole spin appears to be ruled out in the gap paradigm, however, which predicts early formation with a mass already in excess of 4 billion solar masses. In this picture, the black hole experiences slow evolution as it departs from its original radio quasar phase and over billions of years not only fails to double its mass but also falls short of regaining its original high spin, such that it is now compatible with a corotating accreting black hole whose dimensionless spin fits best in the range 0.2 < a < 0.5.     

Generalized Uncertainty Principle and Black Hole Entropy of Higher-Dimensional de Sitter Spacetime

Recently, there has been much attention devoted to resolving the quantum corrections to the BekensteinHawking black hole entropy. In particular, many researchers have expressed a vested interest in the coefficient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the correction value of the black hole entropy by utilizing the generalized uncertainty principle and obtain the correction term caused by the generalized uncertainty principle. Because in our calculation we think that the Bekenstein-Hawking area theorem is still valid after considering the generalized uncertainty principle, we derive that the coefficient of the logarithmic term of the black hole entropy correction term is positive. This result is different from the known result at present. Our method is valid not only for four-dimensional spacetimes but also for higher-dimensional spacetimes. In the whole process, the physics idea is clear and calculation is simple. It offers a new way for studying the entropy correction of the complicated spacetime.     

Generalized Uncertainty Principle and Black Hole Entropy of Higher-Dimensional de Sitter Spacetime

Recently, there has been much attention devoted to resolving the quantum corrections to the Bekenstein-- Hawking black hole entropy. In particular, many researchers have expressed a vested interest in the coetticient of the logarithmic term of the black hole entropy correction term. In this paper, we calculate the correction value of the black hole entropy by utilizing the generalized uncertainty prlnciple and obtain the correction term caused by the generalized uncertainty principle. Because in our calculation we think that the Bekenstein-Hawking area theorem is still valid after considering the generalized uncertainty principle, we derive that the coefficient of the logarithmic term of the black hole entropy correction term is positive. This result is different from the known result at present. Our method is valid not only for four-dimensional spacetimes but also for higher-dimensional spacetimes. In the whole process, the physics idea is clear and calculation is simple. It offers a new way for studying the entropy correction of the complicated spacetime.     

The Quantum Entropy in Horowitz-Strominger Black Hole Background

Using 't Hooft's brick wall model and Newman-Penrose's spinor analysis, the expression of the quantum entropy is derived in the Horowitz-Strominger black hole background. The calculations show us that the Fermionic entropy is 7/2 times the Bosonic entropy.     

椭圆柱形光学黑洞红外辐射特性分析

本文主要采用时域有限差分(FDTD)方法计算了二维椭圆柱形光学黑洞的红外辐射特性。并且采用几何光学近似(GOA)对椭圆柱形的光学黑洞的光线入射轨迹进行分析和比较。研究结果表明,FDTD计算的光学黑洞内的能流分布结果与GOA计算的光学黑洞内的光线入射轨迹结果相吻合,椭圆柱形光学黑洞的红外辐射特性主要受折射率梯度和入射波长的影响。     

Comments on the Statistical Origin of Black Hole Entropy

This paper shows that the black hole entropy can be interpreted as emerging as a result of missing information about the exact state of the matter from which the black hole was formed.     

水下变焦镜头的设计

通过对光在水中传播特性的分析，讨论水下摄影中需要特殊考虑的关键因素，如光能衰减、镜头视场损失和内腔防水等，分析普通相机加隔水窗后在水中拍摄时像质变差的规律。为了适应深水探测，获得清晰成像质量，基于光焦度分配公式，提出了水下变焦镜头设计思想。用实例说明水下镜头的设计方法，设计的镜头相对孔径为F/1.6。设计结果表明：该镜头克服了普通镜头水下使用像质变差和最大视场渐晕等缺点。     

Area Spectrum of Near Extremal Black Branes from Quasi-Normal Modes

Bekenstein and others propose that the black hole area spectrum is discrete and equally spaced. We implement Kunstatter's method to derive the area spectrum for near extremal black 3-branes. The area spectrum of the event horizon is discrete but not equally spaced.     

Harrison Metrics for the Schwarzschild Black Hole

Based on the hidden conformed symmetry, some authors have proposed a Harrison metric for the Schwarzschild black hole. We give a procedure which can generate a family of Harrison metrics starting from a general set of SL（2, R） vector fields. By analogy with the subtracted geometry of the Kerr black hole, we find a new Harrison metric for the Schwaxzschild case. its conformal generators axe also investigated using the Killing equations in the near-horizon limit.