检索结果-南通市图书馆

Hawking radiation from the charged and magnetized BTZ black hole via covariant anomaly

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2009年第2期18卷 462-467页

作者：曾晓雄杨树政 institute of Theoretical physics China West Normal University Department of physics and Engineering Technology Sichuan University of Arts and Science

This paper discusses Hawking radiation from the charged and magnetized Bafiados-Teitelboim-Zanelli （BTZ） black hole from the viewpoint of anomaly, initiated by Robinson and Wilczek recently. It reconstructs the electromagnetic field tensor and the Lagrangian of the field corresponding to the source with electric and magnetic charges to redefine an equivalent charge and gauge potential. It employs the covariant anomaly cancellation method to determine the compensating fluxes of charge flow and energy-momentum tensor, which are shown to match with those of the 2- dimensional blackbody radiation at the Hawking temperature exactly.

关键词： Hawking radiation covariant anomaly event horizon BTZ black hole

Holographic cusped Wilson loops in q-deformed Ad S_5×S^5 spacetime

在线全文

学校读者我要写书评

暂无评论

Chinese physics C 2015年第10期39卷 15-23页

作者：白楠陈辉煌吴俊宝 institute of High Energy physics and Theoretical Physics Center for Science FacilitiesChinese Academy of Sciences

In this paper, a minimal surface in q-deformed AdS5 × S5 with a cusp boundary is studied in detail. This minimal surface is dual to a cusped Wilson loop in dual field theory. We find that the area of the minimal surface has both logarithmic squared divergence and logarithmic divergence. The logarithmic squared divergence cannot be removed by either Legendre transformation or the usual geometric subtraction. We further make an analytic continuation to the Minkowski signature, taking the limit such that the two edges of the cusp become light-like, and extract the anomalous dimension from the coefficient of the logarithmic divergence. This anomalous dimension goes back smoothly to the results in the undeformed case when we take the limit that the deformation parameter goes to zero

关键词： AdS/CFT Wilson loops

Development of lead-free multifunctional materials Bi(Co_(0.45Ti0.45Fe0.10)O3

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2018年第3期28卷 308-314页

作者： Nitin Kumar Alok Shukla R.N.P.Choudhary Department of physics National Institute of Technology Mizoram Department of physics Siksha ‘O′Anusandhan University

A lead free multiferroic material,Bi(Co0.45Ti0.45Fe0.10)O3（BCTF45/10）was synthesized by a solid-state reaction route at high ***45/10 powder was prepared using appropriate raw maretials in oxide powders with methanol ***-prepared circular shaped pellets were sintered at 1053 K for 6 h to produce a compact *** structural properties and elemental analysis were determined using X-ray diffraction and energy-dispersive X-ray spectroscopy techniques respectively at room *** microstructure or surface morphology of the sintered sample was carried out by using field emission scanning electron microscope（FE-SEM）.The XRD analysis shows that the compound exhibits the single-phase of orthorhombic *** average crystallite size estimated using the Scherrer's technique was found to be 30 *** influence of Co and Ti substitution（at Bi and Ti sites of Bi Fe O3）on some physical and electrical properties of Bi Fe O3was examined by using phase sensitive multimeter in a wide frequency and temperature *** magnetic nature of the sample was studied using vibrating sample *** of room temperature magnetic hysteresis loop exhibits the enhanced ferromagnetic characteristic with saturation magnetization of 5.091 emu/g and coercive field of 0.213 k Oe *** enhanced magnetic properties highlight various potential applications of Co/Ti doped BCTF45/10 materials.

关键词： Multifunctional material Dielectric constant and loss Electrical characteristics Impedance spectroscopy

Doping effects on the stacking fault energies of the γ' phase in Ni-based superalloys

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese physics B 2020年第2期29卷 390-395页

作者： Weijie Li Chongyu Wang Department of physics Tsinghua UniversityBeijing 100084China institute of Applied physics and Computational Mathematics Beijing 100088China

The doping effects on the stacking fault energies(SFEs),including the superlattice intrinsic stacking fault and superlattice extrinsic stacking fault,were studied by first principles calculation of the/phase in the Ni-based *** formation energy results show that the main alloying elements in Ni-based superalloys,such as Re,Cr,Mo,Ta,and W,prefer to occupy the Al-site in Ni3 AI,Co shows a weak tendency to occupy the Ni-site,and Ru shows a weak tendency to occupy the *** SFE results show that Co and Ru could decrease the SFEs when added to fault planes,while other main elements increase *** double-packed superlattice intrinsic stacking fault energies are lower than superlattice extrinsic stacking fault energies when elements(except Co) occupy an ***,the SFEs show a symmetrical distribution with the location of the elements in the ternary model.A detailed electronic structure analysis of the Ru effects shows that SFEs correlated with not only the symmetry reduction of the charge accumulation but also the changes in structural energy.

关键词： stacking fault energy site preference Ni-based superalloys electronic structure

Controllable growth of low-dimensional nanostructures on well-defined surfaces

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2013年第9期22卷 120-134页

作者：秦志辉 State Key Laboratory of Magnetic Resonance and Atomic and Molecular physics Wuhan Institute of Physics and MathematicsChinese Academy of Sciences

The controllable growth of nanostructures with desired geometric order and well-defined shapes has stimulated great interest due to its applicability in the development of microelectronic devices. Self-assembly is an efficient and versatile way to guide the atoms or molecules into low-dimensional nanostructures as a consequence of balancing complex interplay between adsorbate-adsorbate and adsorbate-substrate interfacial interactions. The tailoring of low-dimensional nanostruc- tures by control of inter-adsorbate and adsorbate-substrate interfacial interactions is reviewed. Such inherent interactions greatly influence not only the size and shape of the growing nanostructures, but also their chemical identity. The degree of interaction between adsorbates can be controlled via preparation procedures, opening up the study of the influence of this phenomenon with respect to reactivity and catalytic behavior. The formation of well-defined molecular layers can be controlled not only by repulsive molecule-molecule interaction but also by symmetry matching or charge transfer be- tween adsorbed molecules and the substrate. It has become obvious that inter-adsorbate and adsorbate-substrate interfacial interactions can be tuned to fabricate diverse surface nanostructures from semiconductor, metallic, and molecular materials.

关键词： nanostructures self-assembly intermolecular interactions scanning tunneling microscopy

The vibron dressing in α-helicoidal macromolecular chains

在线全文

学校读者我要写书评

暂无评论

Chinese physics B 2013年第6期22卷 218-227页

作者： D.evizovi S. Galovi A. Reshetnyak Z. Ivi University of Belgrade Vina Institute of Nuclear Sciences Laboratory for Theoretical and Condensed Matter PhysicsP. O. Box 522 11001 Belgrade Serbia Joint institute for Nuclear Research Bogoliubov Laboratory for Theoretical physics Dubna Russia Laboratory of Non-Linear Media physics Institute of Strength Physics and Materials ScienceTomsk 634021 Russia

We present a study of the physical properties of the vibrational excitation in α-helicoidal macromolecular chains, caused by the interaction with acoustical and optical phonon modes. The influence of the temperature and the basic system parameters on the vibron dressing have been analyzed by employing the simple mean-field approach based on the variational extension of the Lang-Firsov unitary transformation. The applied approach predicts a region in system parameter space where one has an abrupt transition from a partially dressed （light and mobile） to a fully dressed （immobile） vibron state. We found that the boundary of this region depends on system temperature and the type of bond among structural elements in the macromolecular chain.

关键词： vibron small-polaron α-helix partial dressing

A DETERMINANT FOR THE TRANSFER MATRIX OF THE ONE-DIMENSIONAL DIRECTED BOND PERCOLATION WITH FURTHER NEIGHBOUR BONDS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 1986年第3期6卷 305-319页

作者：张昭庆,蒲富恪,李伯臧 institute of physics Chinese Academy of Sciences Beijing institute of physics Chinese Academy of Sciences Beijing institute of physics Chinese Academy of Sciences Beijing

The rigorous proof of the relation det is given. This relation has been used to obtain the exact critical surface and the correlation length exponents of the one-dimensional directed bond percolation problem with bonds connecting 1～Lth nearest neighbours. A（L）is related to the transfer-matrix by （7）. qiis related to the occupation probability of the i-th nearest neighbour bond piby qi=1-pi（i=1, 2, ..., L）. fLis a multi-varlable polynomial in q4's.

关键词： A DETERMINANT FOR THE TRANSFER MATRIX OF THE ONE-DIMENSIONAL DIRECTED BOND PERCOLATION WITH FURTHER NEIGHBOUR BONDS

Particle-in-cell investigation on the resonant absorption of a plasma surface wave

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese physics B 2011年第10期20卷 319-324页

作者：蓝朝晖胡希伟 institute of Fluid physics China Academy of Engineering Physics College of Electrical and Electronic Engineering Huazhong University of Science and Technology

The resonant absorption of a plasma surface wave is supposed to be an important and efficient mechanism of power deposition for a surface wave plasma source. In this paper, by using the particle-in-cell method and Monte Carlo simulation, the resonance absorption mechanism is investigated. Simulation results demonstrate the existence of surface wave resonance and show the high efficiency of heating electrons. The positions of resonant points, the resonance width and the spatio-temporal evolution of the resonant electric field are presented, which accord well with the theoretical results. The paper also discusses the effect of pressure on the resonance electric field and the plasma density.

关键词： particle-in-cell simulation plasma surface wave resonant absorption

Marangoni-flow-assisted assembly of single-walled carbon nanotube films for human motion sensing

在线全文

学校读者我要写书评

暂无评论

Fundamental Research 2024年第3期4卷 570-574页

作者： Yuguang Chen Yitan Li Lu Han Hao Sun Min Lyu Zeyao Zhang Shigeo Maruyama Yan Li Key Laboratory for the physics and Chemistry of Nanodevices Beijing National Laboratory of Molecular SciencesState Key Laboratory of Rare Earth Materials Chemistry and ApplicationsCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China Academy for Advanced Interdisciplinary Studies Peking UniversityBeijing 100871China Bruker(Beijing)Scientific Technology Co.Ltd. Beijing 100192China Department of Mechanical Engineering The University of TokyoTokyo 113-8656Japan Peking University Shenzhen institute Shenzhen 518057China PKU-HKUST ShenZhen-HongKong Institution Shenzhen 518057China

Single-walled carbon nanotubes(SWCNTs)present excellent electronic and mechanical properties desired in wearable and flexible *** preparation of SWCNT films is the first step for fabricating various *** work developed a scalable and feasible method to assemble SWCNT thin films on water surfaces based on Marangoni flow induced by surface tension *** films possess a large area of 40 cm×30 cm(extensible),a tunable thickness of 15∼150 nm,a high transparency of up to 96%,and a decent *** are ready to be directly transferred to various substrates,including flexible *** strain sensors were fabricated with the films on flexible *** sensors worked with high sensitivity and *** realizing multi-functional human motion sensing,including responding to voices,monitoring artery pulses,and detecting knuckle and muscle actions,the assembled SWCNT films demonstrated the potential for application in smart devices.

关键词： Single-walled carbon nanotubes Marangoni flow Assembly Interfaces Sensors