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黑洞熵无截断薄层模型的改进与推广

物理学报 2004年第11期53卷 4002-4006页

作者：孙学锋景玲刘文彪北京师范大学物理学系理论物理研究所北京100875

将广义测不准关系引入薄层brickwall模型 ,撇开截断因子计算黑洞熵的方法于 2 0 0 2年首次提出 .当时这个方法尚存在一些问题 ,只得到了熵的上限与视界面积成正比 .对这个方法做了些改进 ,得到熵与视界面积成正比的结果 ,并讨论了比例... 详细信息

将广义测不准关系引入薄层brickwall模型 ,撇开截断因子计算黑洞熵的方法于 2 0 0 2年首次提出 .当时这个方法尚存在一些问题 ,只得到了熵的上限与视界面积成正比 .对这个方法做了些改进 ,得到熵与视界面积成正比的结果 ,并讨论了比例因子与广义测不准关系中二阶项待定系数的关系 .然后把这种方法推广到非球对称的Rindler视界 ,得到了预期的结果 .

关键词：测不准关系二阶引力场球对称因子量子化视界黑洞熵薄层模型

Re-study of Nucleon Pole Contribution in J/ψ→N(?)π Decay

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Communications in theoretical {1. 2006年第9期46卷 507-513页

作者： ZONG Yuan-Yuan,~(1.2) SHEN Peng-Nian,~(1.3,4) ZOU Bing-Song,~(1.3,4) liu Ji-Feng,~2 LIANG Wei-Hong~2 1.Institute of High Energy {1., the Chinese Academy of Sciences, P.O. Box 91.(4), beijing 1.0049, china 2 department of {1., Guangxi normal university, Guilin 541.04, china 3 Center of theoretical Nuclear {1., National Laboratory of Heavy Ion Accelerator, Lanzhou 730000, china 4 Institute of theoretical {1., the Chinese Academy of Sciences, beijing 1.0080, china Institute of High Energy physics the Chinese Academy of Sciences P.O. Box 9184 Beijing 100049 department of {1. Guangxi Normal University Guilin 541004

We re-study nucleon pole contribution in J/ψ→NNπ decays by including the imaginary part for the propagator of the off-shell nucleon with energy above πN threshold. It is found that when including the imaginary part in the propagator, the branching ratio of the decay width will descend about 1.% compared with the result without including the imaginary part, no matter whether including the off-shell form factors or not. It also leads to a phase of up to 25° for the off-shell nucleon propagator at invariant mass around 1.00 MeV. This effect needs to be considered for detailed partial wave analysis of N* resonances around this mass region.

关键词： J/ψ decay form factor

Advantageous properties of halide perovskite quantum dots towards energy-efficient sustainable applications

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Green Energy & Environment 2024年第6期9卷 949-965页

作者： Qian Zhao Shuo Wang Young-Hoon Kim Shekhar Mondal Qingqing Miao Simiao Li Danya liu Miao Wang Yaxin {1. Jianbo Gao Abhijit Hazarika Guo-Ran Li School of Materials Science and Engineering Nankai UniversityTianjin300350China department of Energy Engineering Hanyang UniversitySeoul04763Republic of Korea Polymers and Functional Materials Division CSIR-Indian Institute of Chemical TechnologyUppal RoadTarnakHyderabad500007India Institute of Process Engineering Chinese Academy of SciencesBeijing100190China Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of Education Department of PhysicsHunan Normal UniversityChangshHunan410081China department of Chemistry Brock University1812 Sir Isaac WaySt CatharinesOntarioCanada

As lead halide perovskite(LHP)semiconductors have shown tremendous promise in many application fields,and particularly made strong impact in the solar photovoltaic area,low dimensional quantum dot forms of these perovskites are showing the potential to make distinct marks in the fields of electronics,optoelectronics and *** so-called perovskite quantum dots(PQDs)not only possess the most important features of LHP materials,i.e.,the unusual high defect tolerance,but also demonstrate clear quantum size effects,along with exhibiting desirable optoelectronic properties such as near perfect photoluminescent quantum yield,multiple exciton generation and slow hot-carrier ***,we review the advantageous properties of these nanoscale perovskites and survey the prospects for diverse applications which include lightemitting devices,solar cells,photocatalysts,lasers,detectors and memristors,emphasizing the distinct superiorities as well as the challenges.

关键词： Perovskite quantum dot Light-emitting Detector Laser Solar cell

Analyzing the surface passivity effect of germanium oxynitride:a comprehensive approach through first principles simulation and interface state density

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Nuclear Science and Techniques 2024年第5期35卷 74-84页

作者： Sheng-Jie Du Xiu-Xia Li Yang Tian Yuan-Yuan liu Ke Jia {1.-Zheng Tang Jian-Ping Cheng Zhi Deng Yu-Lan Li Zheng-Cao Li Sha-Sha Lv College of Nuclear Science and Technology Joint Laboratory of Jinping Ultra‑Low Radiation Background Measurement of Ministry of Ecology and Environment Key Laboratory of Beam Technology of Ministry of Education Beijing Normal UniversityBeijing Normal UniversityBeijing 100875China Joint Research Center Nuctech Company LimitedBeijing 100084China department of Engineering {1. Key Laboratory of Particle&Radiation Imaging of Ministry of EducationTsinghua UniversityBeijing 100084China Key Laboratory of Advanced Materials(MOE) School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

High-purity germanium(HPGe)detectors,which are used for direct dark matter detection,have the advantages of a low threshold and excellent energy *** surface passivation of HPGe has become crucial for achieving an extremely low energy *** this study,first-principles simulations,passivation film preparation,and metal oxide semiconductor(MOS)capacitor characterization were combined to study surface *** calculations of the energy band structure of the -H,-OH,and -NH_(2) passivation groups on the surface of Ge were performed,and the interface state density and potential with five different passivation groups with N/O atomic ratios were accurately analyzed to obtain a stable surface *** on the theoretical calculation results,the surface passivation layers of the Ge_(2)ON_(2) film were prepared via magnetron sputtering in accordance with the optimum atomic ratio *** microstructure,C-V,and I-V electrical properties of the layers,and the passivation effect of the Al/Ge_(2)ON_(2)/Ge MOS were characterized to test the interface state *** mean interface state density obtained by the Terman method was 8.4×1.^(1.) cm^(-2) eV^(-1..The processing of germanium oxynitrogen passivation films is expected to be used in direct dark matter detection of the HPGe detector surface passivation technology to reduce the detector leakage currents.

关键词： Surface passivation High purity germanium detector Germanium nitrogen oxide Interface state density

Analysis on the characteristics of animal tissues based on the Terahertz time domain spectroscopy system

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Analysis on the characteristics of animal tissues based on t...

HiFAST:An HIdata calibration and imaging pipeline for FAST

中国光学学会201.年学术大会

作者： LU Cheng-zhen 1,liu Chen 1,CUI Er-liang 1,LI Jia 1,liu Wei 1,SUN Ping 2(1.department of physics,Capital normal university,beijing 100048,P.R.china beijing Key Laboratory for Terahertz Spectroscopy and Imaging,Key Laboratory of Terahertz Optoelectronics,Ministry of Education,beijing 100048,P.R.china 2.department of physics,beijing normal university,beijing Area Major Laboratory of Applied Optics,beijing 1.0875,PR china)

Terahertz time domain spectroscopy（THz-TDS） technique is a novel and very effective coherent detection method based on femtosecond laser *** has the advantages of non-ionization and low average power,thus it is not thought to be dangerous when THz waves penetrate through the skin *** with visible and infrared light,it also has the characteristics of low scattering,and the surface character and depth pattern of samples can be gotten at the same ***,it makes the terahertz detection in the field of biomedicine possible to measure the tissue in vivo without any *** in 2002,Knobloch.p et al investigated the metastasis of some biological samples including the larynx of a pig and a human liver in the terahertz imaging *** the same time,skin tissue and related cancers both in vitro and in vivo were studied by *** et *** 2004,the more systematic research of the response of terahertz radiation to normal skin in vivo was made by *** et *** 201.,*** studied terahertz time domain spectroscopy characterization of human thumb skin in reflection system with waveform rebuilding *** this work,the THz spectral properties of several of fresh animal tissues are studied base on the time domain *** pulse transmission spectra of different animal tissues slices with different thickness is obtained,and the refractive index,absorption and extinction coefficient of these tissues is analyzed and *** to the double Debye model,tissues parameters are simulated and *** {1. and experimental result is *** works is helpful to make further research of the THz spectral performances of human tissues and cancers.

关键词： animal tissues transmission double Debye model Terahertz time domain spectroscopy

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Science china({1.,Mechanics & Astronomy) 2024年第5期67卷 182-199页

作者： Yingjie Jing Jie Wang Chen xu Ziming {1. Qingze Chen Tiantian Liang Jinlong xu Yixian Cao Jing Wang Huijie Hu Chuan-Peng Zhang Qi Guo Liang Gao Mei Ai Hengqian Gan xuyang Gao Jinlin Han Ligang Hou Zhipeng Hou Peng Jiang xu Kong Fujia Li Zerui {1. Li Shao Hengxing Pan Jun Pan Lei Qian Jinghai Sun Ningyu Tang Qingliang Yang Bo Zhang Zhiyu Zhang Ming Zhu National Astronomical Observatories Chinese Academy of SciencesBeijing 100012China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 02206China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China Guizhou Radio Astronomical Observatory Guizhou UniversityGuiyang 55000China Max Planck Institute for Extraterrestrial physics Garching 85748Germany Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Institute of Computational Cosmology Department of PhysicsUniversity of DurhamDurham DHI 3LEUK CAS Key Laboratory of FAST National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Deep Space Exploration Laboratory/department of Astronomy University of Science and Technology of ChinaHefei 230026China School of Astronomy and Space Science University of Science and Technology of ChinaHefei 230026China Astrophysics Department of PhysicsUniversity of OxfordOxford OX/3RHUK College of Earth Sciences Guilin University of TechnologyGuilin 541004China department of {1. Anhui Normal UniversityWuhu 241002China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 20023China

The Five-hundred-meter Aperture Spherical radio Telescope(FAST)has the largest aperture and a 1.-beam L-band receiver,making it powerful for investigating the neutral hydrogen atomic gas(HI)in the *** present HiFAST(https://***),a dedicated,modular,and self-contained calibration and imaging pipeline for processing the H?data of *** pipeline consists of frequency-dependent noise diode calibration,baseline fitting,standing wave removal using an FFT-based method,flux density calibration,stray radiation correction,and gridding to produce data *** modules can be combined as needed to process the data from most FAST observation modes:tracking,drift scanning,On-The-Fly mapping,and most of their *** HiFAST,the root-mean-square(RMS)noises of the calibrated spectra from all 1. beams were only slightly(~5%)higher than the theoretical *** results for the extended source M33 and the point sources are consistent with the results from *** moment maps(0,1.and 2)of M33 agree well with the results from the Arecibo Galaxy Environment Survey(AGES)with a fractional difference of less than 1.%.For a common sample of 221.sources with signal-to-noise ratio S/N>1. from the Arecibo Legacy Fast ALFA(ALFALFA)survey,the mean value of fractional difference in the integrated flux density,Sint,between the two datasets is approximately 0.005%,with a dispersion of 1..4%.Further checks on the integrated flux density of 23 sources with seven observations indicate that the variance in the flux density of the source with luminous objects(Sint>2.5 Jy km s-1.is less than 5%.Our tests suggest that the FAST telescope,with the efficient,precise,and user-friendly pipeline HiFAST,will yield numerous significant scientific findings in the investigation of the H?in the universe.

关键词： fractional luminous correction

Photon sphere and phase transition of ddimensional(d≥5) charged Gauss–Bonnet AdS black holes

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Communications in theoretical {1. 2020年第10期72卷 131-138页

作者： Shan-zhong Han Jie Jiang Ming Zhang {1.-biao liu department of {1. Beijing Normal UniversityBeijing 100875China College of physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China Perimeter Institute for theoretical {1. WaterlooOntario N2L 2Y5Canada department of {1. and Astronomy University of WaterlooOntario N2L 3G1Canada

Motivated by recent work,nonmonotonic behaviors of photon sphere radius can be used to reflect black hole phase transition for Reissner–Nordstr?m–AdS(RN–AdS)black holes,we study the case of five-dimensional charged Gauss–Bonnet–AdS black holes in the reduced parameter *** find that the nonmonotonic behaviors of photon sphere radius still *** the coexistence line calculated from P–V plane,we capture the photon sphere radius of saturated small and large black holes(the boundary of the coexistence phase),then illustrate the reduced coexistence *** results show that,reduced coexistence region decreases with charge Q but increases with Gauss–Bonnet coefficientα.When the charge vanishes,reduced coexistence region does not vary with Gauss–Bonnet coefficientαany *** this case,the Gauss–Bonnet coefficientαplays the same role as the charge of five-dimensional RN–AdS black ***,the situation of higher dimension is studied in the end.

关键词： Gauss–Bonnet AdS black hole phase transition photon sphere black hole thermodynamics

A bound on the effective boson number from shape phase transition in IBM

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A bound on the effective boson number from shape phase trans...

Estimations of cosmological parameters from the observational variation of the fine structure constant

第十三届全国核结构研讨会暨第九次全国“核结构与量子力学”专题讨论会

作者： Yu Zhang~(1 2)) Zhan-feng Hou~(2)) Yu-xin liu~(2 3)) Feng Pan~(1)) 1(department of physics,Liaoning normal university,Dalian 116029,china) 2(department of physics and State Key Laboratory of Nuclear physics and Technology Peking university,beijing 100871, china) 3(Center of theoretical Nuclear physics,National Laboratory of Heavy Ion Accelerator,Lanzhou 730000,china)

We study the effects driven by the boson number on the critical behavior of some observable quantities that are sensitive to the nuclear shape phase transitions in the interacting boson model（IBM）.By comparing the experiments with the theory calculation,we find that the effective boson number in IBM best consistent to experiments is not more than the total pairs number of valence nucleons or holes,and an up bound of the effective boson number can be found in the U（5）-O（6） transition region at least in ***, two trajectories of second order phase transitions,the isotones with neutron number N_n=62 and the one with N_n=74,are confirmed by comparing the observable quantities in experiments with those in theory

关键词： keyword1 keyword2 keyword3 keyword4

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Research in Astronomy and Astrophysics 2013年第12期13卷 1423-1437页

作者： zhong-{1. zhai Xian-Ming liu Zhi-Song Zhang Tong-Jie Zhang department of Astronomy Beijing Normal University department of {1. Institute of Theoretical PhysicsBeijing Normal University department of {1. Hubei University for Nationalities department of Aerospace Engineering School of AstronauticsHarbin Institute of Technology(HIT) Center for High Energy physics Peking University

We present constraints on the quintessence scalar field model from observational data of the variation of the fine structure constant obtained from the Keck telescope and VLT. Within the theoretical frame proposed by Bekenstein, the constraints on the parameters of the quintessence scalar field model are obtained. Considering the prior of Ωm0 as WMAP 7 suggests, we obtain various results from different sam- ples. Based on these results, we also calculate the probability density function of the coupling constant ζ. The best-fit values show a consistent relationship between ζ and the different experimental results. In our work, we test two different potential models, namely, the inverse power law potential and the exponential potential. The results show that both the large value of the parameters in the potential and the strong coupling can cause a variation in the fine structure constant.

关键词： quasars: general- scalar field - cosmological constraint