期刊文献+
共找到5,417篇文章
< 1 2 250 >
每页显示 20 50 100
Higher-order squeezing of quantum field and higher-order uncertainty relations in non-degenerate four-wave mixing
1
作者 李希曾 苏保霞 柴路 《Chinese Physics B》 SCIE EI CAS CSCD 2005年第9期1828-1833,共6页
It is found that the field of the combined mode of the probe wave and the phase conjugate wave in the process of non-degenerate four-wave mixing exhibits higher-order squeezing to all even orders. The higher-order squ... It is found that the field of the combined mode of the probe wave and the phase conjugate wave in the process of non-degenerate four-wave mixing exhibits higher-order squeezing to all even orders. The higher-order squeezed parameter and squeezed limit due to the modulation frequency are investigated. The smaller the modulation frequency is, the stronger the degree of higher-order squeezing becomes. Furthermore, the hlgher-order uncertainty relations in the process of non-degenerate four-wave mixing are presented for the first time. The product of higher-order noise moments is related to even order number N and the length L of the medium. 展开更多
关键词 higher-order squeezing higher-order uncertainty relations quantum fields non-degenerate four-wave mixing
下载PDF
Higher-Order Fluctuations and SU(1,1) Higher-Order Squeezing in SU(1,1) Generalized Coherent States
2
作者 董传华 《Journal of Shanghai University(English Edition)》 CAS 2002年第4期297-302,共6页
The higher order fluctuations in the SU(1,1) generalized coherent states are discussed. The definition of higher order SU(1,1) squeezing is introduced in terms of higher order uncertainty relation. For two poss... The higher order fluctuations in the SU(1,1) generalized coherent states are discussed. The definition of higher order SU(1,1) squeezing is introduced in terms of higher order uncertainty relation. For two possible bosonic realizations of SU(1,1) Lie algebra, the second , fourth and sixth order SU(1,1) squeezing are examined in detail. It is shown that the SU(1,1) generalized coherent states can be squeezed to not only second order, but also fourth and sixth order. Hence, it follows that the higher order squeezing will occur for the fluctuations of the square of amplitude in squeezed vacuum. SU(1,1) higher order squeezing is a kind of non classical property which is independent of second order squeezing. 展开更多
关键词 squeezing higher order squeezing SU(1 1) coherent state SU(1 1) squeezing.
下载PDF
Higher-Order Squeezing for Atomic Dipole of a Three-Level Atom in the Kerr-Like Medium Cavity Fields
3
作者 卢俊 许毅 董传华 《Journal of Shanghai University(English Edition)》 CAS 2003年第1期49-54,共6页
In this paper, evolution of the higher order squeezing for atomic dipole of three level atom in the Kerr like medium is investigated. The atom discussed has two configurations and is driven by the single mode cohe... In this paper, evolution of the higher order squeezing for atomic dipole of three level atom in the Kerr like medium is investigated. The atom discussed has two configurations and is driven by the single mode coherent state field. Our results show that the squeezing effects are clearly influenced by nonlinear parameters, the initial atom state and the detuning. 展开更多
关键词 J C model higher order squeezing three level atom atomic dipole moment.
下载PDF
Generation of Higher-Order Squeezing in Multiphoton Micromaser
4
作者 Huang Qing (Department of Applied Physics Soulhwest Jiaotong University), Chengdu 61 0031 .ChinaLi Fuli (Department of Applied Physics,Xi’an Jiaotong University,) Xi’an 7 1 004 9 , China 《Journal of Modern Transportation》 1995年第2期133-142,共10页
The generation of study state hisher-Order squeezing in the sense of Hons andMandel [Phys. Rey. Lett. 54, 323 (1985) ; phys. Rev. A32,974 ( 1985 )] andalso of Hillery [Phys. Rev. A36 , 3796 (1987) ] in a multiphoton m... The generation of study state hisher-Order squeezing in the sense of Hons andMandel [Phys. Rey. Lett. 54, 323 (1985) ; phys. Rev. A32,974 ( 1985 )] andalso of Hillery [Phys. Rev. A36 , 3796 (1987) ] in a multiphoton micromaser isstudied. The results show that the cotangent state which is generated by thecoherent trapping scheme in a niultiphoton microniaser can exhibit not onlysecond-order squeezing but alaso fourth-order and squared field aniplitudesqueezing. The influence of the cavity loss on the squeezings is investigated. 展开更多
关键词 one-atom micromaser hisher-order squeezing coherent trapping cavity loss
下载PDF
Photon higher-order squeezing effects of the q analogue of a single-mode field interacting with a -type three-level atom
5
作者 张慧慧 申华军 +1 位作者 周静涛 刘新宇 《Chinese Physics C》 SCIE CAS CSCD 2009年第8期622-625,共4页
The nonlinear theory of interaction between the q analogue of a single-mode field and a Ξ-type threelevel atom has been established. And the formal solution of the Schrodinger equation in the representation and its a... The nonlinear theory of interaction between the q analogue of a single-mode field and a Ξ-type threelevel atom has been established. And the formal solution of the Schrodinger equation in the representation and its average number are obtained. Then, the photon squeezing effects are studied through numerical calculation. The results show that the q deformation nonlinear action has a lot of influence on the quantum coherence and quantum properties. When q approaches 1, the theory reduces to the common linear theory. 展开更多
关键词 quantum optics quantum properties q deformation higher-order squeezing effects
原文传递
Photoinduced Floquet higher-order Weyl semimetal in C_(6) symmetric Dirac semimetals
6
作者 许欣欣 王梓名 +1 位作者 许东辉 陈垂针 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期109-117,共9页
Topological Dirac semimetals are a parent state from which other exotic topological phases of matter, such as Weyl semimetals and topological insulators, can emerge. In this study, we investigate a Dirac semimetal pos... Topological Dirac semimetals are a parent state from which other exotic topological phases of matter, such as Weyl semimetals and topological insulators, can emerge. In this study, we investigate a Dirac semimetal possessing sixfold rotational symmetry and hosting higher-order topological hinge Fermi arc states, which is irradiated by circularly polarized light. Our findings reveal that circularly polarized light splits each Dirac node into a pair of Weyl nodes due to the breaking of time-reversal symmetry, resulting in the realization of the Weyl semimetal phase. This Weyl semimetal phase exhibits rich boundary states, including two-dimensional surface Fermi arc states and hinge Fermi arc states confined to six hinges.Furthermore, by adjusting the incident direction of the circularly polarized light, we can control the degree of tilt of the resulting Weyl cones, enabling the realization of different types of Weyl semimetals. 展开更多
关键词 Dirac semimetals Weyl semimetals periodic driving higher-order topology
下载PDF
Higher-order expansions of powered extremes of logarithmic general error distribution
7
作者 TAN Xiao-feng LI Li-hui 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2024年第1期47-54,共8页
In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥1.Higher-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of nor... In this paper,Let M_(n)denote the maximum of logarithmic general error distribution with parameter v≥1.Higher-order expansions for distributions of powered extremes M_(n)^(p)are derived under an optimal choice of normalizing constants.It is shown that M_(n)^(p),when v=1,converges to the Frechet extreme value distribution at the rate of 1/n,and if v>1 then M_(n)^(p)converges to the Gumbel extreme value distribution at the rate of(loglogn)^(2)=(log n)^(1-1/v). 展开更多
关键词 logarithmic general error distribution convergence rate higher-order expansion powered ex-treme
下载PDF
Hydromagnetic Squeezing Nanofluid Flow between Two Vertical Plates in Presence of a Chemical Reaction
8
作者 Benjamin Matur Madit Jackson K. Kwanza Phineas Roy Kiogora 《Journal of Applied Mathematics and Physics》 2024年第1期126-146,共21页
In this study, Hydromagnetic Squeezing Nanofluid flow between two vertical plates in presence of a chemical reaction has been investigated. The governing equations were transformed by similarity transformation and the... In this study, Hydromagnetic Squeezing Nanofluid flow between two vertical plates in presence of a chemical reaction has been investigated. The governing equations were transformed by similarity transformation and the resulting ordinary differential equations were solved by collocation method. The velocity, temperature, concentration and magnetic induction profiles were determined with help of various flow parameters. The numerical scheme was simulated with aid of MATLAB. The results showed that increasing the squeeze number only boosts velocity and concentration while lowering temperature. Conversely, increasing the Hartmann number, Reynold’s magnetic number, Eckert number and Thermal Grashof number generally increases temperature but decreases both velocity and concentration. Chemical reaction rate and Soret number solely elevate concentration while Schmidt number only reduces it. The results of this study will be useful in the fields of oil and gas industry, plastic processing industries, filtration, food processing, lubrication system in machinery, Microfluidics devices for drug delivery and other related fields of nanotechnology. 展开更多
关键词 HYDROMAGNETIC squeezing Flow NANOFLUID Variable Magnetic Field Chemical Reaction
下载PDF
A Study of a Moral Dilemma Stories Teaching Model Focusing on the Development of Higher-Order Thinking --"Synthetic polymers" as an example
9
作者 Lin Tang Yi Dai 《教育技术与创新》 2024年第1期27-35,共9页
Cultivating students'higher-order thinking is one of the important goals of modern education,and innovative teaching model is an effective way to achieve this goal.Aiming at the inadequacy of the existing moral di... Cultivating students'higher-order thinking is one of the important goals of modern education,and innovative teaching model is an effective way to achieve this goal.Aiming at the inadequacy of the existing moral dilemma stories approach in the transformation of knowledge and behavior,this research constructs a new Project Based Learning-Ethical Dilemma Stories(PBL-EDS)Teaching Model applicable to China's secondary education stage based on the innovative features of the moral dilemma stories approach on the core competencies,taking the chemistry subject as an example to carry out practice,and puts forward suggestions for the implementation of the teaching model.Chemistry as an example to carry out the practice,and suggestions are made for the implementation of the teaching model. 展开更多
关键词 higher-order thinking moral dilemma stories teaching model secondary education
下载PDF
Supporting structure failure caused by the squeezing tunnel creep and its reinforcement measure 被引量:1
10
作者 ZHAO Jin-peng TAN Zhong-sheng +1 位作者 LI Lei WANG Xiu-ying 《Journal of Mountain Science》 SCIE CSCD 2023年第6期1774-1789,共16页
Tunnels deeply buried have high crustal stress and are prone to large deformation disasters when encountering soft rock.The large deformation phenomenon during the construction process of the Maoxian Tunnel on the Che... Tunnels deeply buried have high crustal stress and are prone to large deformation disasters when encountering soft rock.The large deformation phenomenon during the construction process of the Maoxian Tunnel on the Chengdu-Lanzhou Railway is particularly evident.This article focuses on the large deformation problem of the No.1 inclined shaft of the Maoxian Tunnel,and uses on-site monitoring methods to explore the reasons for tunnel structure failure,and analyzes the mechanical behavior of the tunnel structure.By using numerical simulation methods,the effectiveness of the second-layer support in resisting creep loads in tunnels was studied,and the influence of the construction time of the secondlayer support on the mechanical properties of the tunnel was discussed.The results indicate that the first-layer support in the tunnel is a structural failure caused by asymmetric deformation caused by creep,while the second-layer support has a good effect on resisting creep loads.The research results can provide a technical reference for deformation control of squeezing tunnels. 展开更多
关键词 squeezing tunnel Mechanical responses Long-term creep Second-layer support On-site monitoring
下载PDF
Design of the yielding support used highly deformable elements for a tunnel excavated in squeezing rock
11
作者 TIAN Hong-ming TIAN Yun +3 位作者 CHEN Wei-zhong TAN Xian-jun SHU Xiao-yun LIU Xia-lin 《Journal of Mountain Science》 SCIE CSCD 2023年第5期1458-1468,共11页
Yielding support is often used in the squeezing tunnel to prevent damage to the lining induced by large deformation of the surrounding rock.Highly Deformable Elements(HDE)which is often installed along the circumferen... Yielding support is often used in the squeezing tunnel to prevent damage to the lining induced by large deformation of the surrounding rock.Highly Deformable Elements(HDE)which is often installed along the circumferential direction of the shotcrete lining is a common type of yielding support.To determine the yield parameters of HDE,the support characteristic of the lining using HDE and the ground pressure considering strain-softening of soft rock were analyzed by an analytical method.The analytical solution showed that when considering the strain-softening of squeezing ground,the ground pressure has a non-zero minimum value.The minimum value of ground stress can be used to determine the constant yield stress of the HDE,and the corresponding deformation of the minimum ground pressure can be used to determine the deformation capacity of the HDE.Based on the variation in the design constant yield stress and yield displacement of HDE with the in-situ stress and the mechanical parameters of the soft rock,equations were proposed for determining of the yield parameters of the HDE. 展开更多
关键词 Highly deformable elements squeezing tunnel Yielding support Strain-softening behavior
下载PDF
Genuine entanglement under squeezed generalized amplitude damping channels with memory
12
作者 Mazhar Ali 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期158-163,共6页
We study genuine entanglement among three qubits undergoing a noisy process that includes dissipation, squeezing,and decoherence. We obtain a general solution and analyze the asymptotic quantum states. We find that mo... We study genuine entanglement among three qubits undergoing a noisy process that includes dissipation, squeezing,and decoherence. We obtain a general solution and analyze the asymptotic quantum states. We find that most of these asymptotic states can be genuinely entangled depending upon the parameters of the channel, memory parameter, and the parameters of the initial states. We study Greenberger–Horne–Zeilinger(GHZ) states and W states, mixed with white noise,and determine the conditions for them to be genuinely entangled at infinity. We find that for these mixtures, it is possible to start with a bi-separable state(with a specific mixture of white noise) and end with genuine entangled states. However, the memory parameter μ must be very high. We find that in contrast to the two-qubit case, none of the three-qubit asymptotic states for n → ∞ are genuinely entangled. 展开更多
关键词 genuine entanglement squeezed thermal baths multipartite states
下载PDF
Higher-Order Fluctuations and Measured Phase Operators in the Squeezed Thermal States
13
作者 Dong Chuanhua (College of Science, Shanghai University) 《Advances in Manufacturing》 SCIE CAS 1999年第1期42-46,共5页
We study the higher order fluctuations and squeezing of quadrature operators in the squeezed thermal states. In terms of measured phase operators, we discuss the fluctuations and squeezing of phases in these states.... We study the higher order fluctuations and squeezing of quadrature operators in the squeezed thermal states. In terms of measured phase operators, we discuss the fluctuations and squeezing of phases in these states. We conclude that the condition of higher order squeezing for quadrature components of the field is order independent and the fluctuations of measured phase operators are temperature independent. 展开更多
关键词 squeezed thermal state higher order squeezing measured phase operator
下载PDF
基于改进SqueezeNet算法的VBE设备电路板元件失效识别研究
14
作者 刘隆晨 杨玥坪 +3 位作者 贾志杰 黄宇 唐世雄 谭博洋 《电源学报》 CSCD 北大核心 2024年第3期236-247,共12页
在直流输电系统中,换流阀阀基电子VBE(valve base electronics)设备的稳定运作对维护直流系统安全至关重要。传统的阀基电子设备电路板(VBE板)元件失效检测方法依赖于耗时的人工检查或基于规则的自动化系统,这些方法通常检测效率低下且... 在直流输电系统中,换流阀阀基电子VBE(valve base electronics)设备的稳定运作对维护直流系统安全至关重要。传统的阀基电子设备电路板(VBE板)元件失效检测方法依赖于耗时的人工检查或基于规则的自动化系统,这些方法通常检测效率低下且准确性有限。针对该问题,提出一种基于改进的SqueezeNet深度学习模型的VBE板元件失效区域识别方法。通过引入深度可分离卷积和残差连接,所提改进SqueezeNet模型旨在提高元件失效检测的准确性,同时降低计算资源的需求。在VBE板元件失效数据集上的实验结果表明,所提方法在元件失效检测准确率和运算效率方面均优于传统方法和标准SqueezeNet模型,准确率达到了95.27%,比原模型高出4.45%。不仅提升了VBE板元件失效检测的效率和准确性,而且为电力系统中类似设备的元件失效诊断提供了新的技术参考。 展开更多
关键词 阀基电子设备 squeezeNet模型 元件失效检测 特征提取
下载PDF
Higher-order nonclassical effects generated by multiple-photon annihilation-then-creation and creation-then-annihilation coherent states
15
作者 袁洪春 徐学翔 +2 位作者 肖进 熊超 朱锡芳 《Chinese Physics B》 SCIE EI CAS CSCD 2016年第5期186-191,共6页
We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilationthen-creation(AC) and creation-then-annihilation(CA) on the coherent state, respectively, such as h... We explore two observable nonclassical properties of quantum states generated by repeatedly operating annihilationthen-creation(AC) and creation-then-annihilation(CA) on the coherent state, respectively, such as higher-order subPoissonian statistics and higher-order squeezing-enhanced effect. The corresponding analytical expressions are derived in detail depending on m. By numerically comparing those quantum properties, it is found that these states above have very different nonclassical properties and nonclassicality is exhibited more strongly after AC operation than after CA operation. 展开更多
关键词 non-Gaussian operation sub-Poissonian statistics higher-order squeezing
下载PDF
APPLICATIONS OF HIGHER-ORDER UPWIND SCHEME FOR PROJECTILES IN TRANSONIC FLOW
16
作者 鞠玉涛 郑亚 武晓松 《兵工学报》 EI CAS CSCD 北大核心 2000年第1期-,共3页
针对弹丸跨音速粘性绕流流场进行了数值仿真研究,并与实验进行了对比。数值仿真的控制方程为雷诺平均的Navier-Stokes方程,湍流模型采用Baldwin-Lomax模型,应用了四阶的MUSCL TVD格式。结果表明,该方法可以取得高清晰度的流场结构。
关键词 TVD格式 NAVIER-STOKES方程 弹丸流动 APPLICATIONS OF higher-order UPWIND SCHEME FOR
下载PDF
The entropic squeezing of superposition of two arbitrary coherent states 被引量:7
17
作者 卢道明 《Chinese Physics B》 SCIE EI CAS CSCD 2008年第2期618-623,共6页
In this paper the superpositions of two arbitrary coherent states |ψ〉 = α |β| + be^iψ |mβe^iδ〉 are constructed by using the superposition principle of quantum mechanics. The entropic squeezing effects of ... In this paper the superpositions of two arbitrary coherent states |ψ〉 = α |β| + be^iψ |mβe^iδ〉 are constructed by using the superposition principle of quantum mechanics. The entropic squeezing effects of the quantum states are studied. The numerical results indicate that the amplitudes, the ratio between the amplitudes of two coherent states, the phase difference between the two components and the relative phase of the two coefficients play important roles in the squeezing effects of the position entropy and momentum entropy. 展开更多
关键词 coherent state superposition state entropy squeezing
下载PDF
Laboratory tests and numerical simulations of brittle marble and squeezing schist at Jinping II hydropower station,China 被引量:11
18
作者 Chunsheng Zhang,Weijiang Chu,Ning Liu,Yongsheng Zhu,Jing Hou East China Investigation and Design Institute,China Hydropower Engineering Consulting Group Co.,Hangzhou,310014,China 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2011年第1期30-38,共9页
Four 16.7 km-long tunnels with diameters ranging from 12.4 to 14.6 m are now under construction at Jinping II hydropower station along the Yalong River.The tunnels pass through Triassic rocks below Jinping Mountain.Th... Four 16.7 km-long tunnels with diameters ranging from 12.4 to 14.6 m are now under construction at Jinping II hydropower station along the Yalong River.The tunnels pass through Triassic rocks below Jinping Mountain.The tunnels are characterized with high overburden,long alignment and complex geological conditions.Brittle failure in marble and squeezing in schist are the primary problems in tunnelling.This paper introduces the studies of laboratory tests on Jinping II marble as well as numerical prediction of excavation damaged zone (EDZ) of tunnel section in brittle marble and determination of reinforced concrete lining thickness for restraining time-dependent deformation in the schist tunnel section.Laboratory tests indicate that Jinping II marble presents a complex brittle-ductile-plastic transition behavior of post-peak response with increasing confining pressure.Such behavior can be described numerically with the Hoek-Brown model.The EDZ was calibrated and predicted using both fast Lagrangian analysis of continua (FLAC) and particle flow code (PFC).The predicted result of EDZ in sections with different qualities of rock mass under various overburden pressures is quite helpful in understanding EDZ characterization and support design.A power-law creep model was used to support the lining design,especially in determining the lining thickness.Field convergence measurement data over 19 months were used to calibrate the creep model properties,followed by a sensibility analysis of reinforced concrete lining thickness that was launched to present the maximum lining compressive stress. 展开更多
关键词 deep tunnel time-dependent behavior excavation damaged zone (EDZ) squeezing MARBLE
下载PDF
Entropy squeezing of an atom with a k-photon in the Jaynes-Cummings model 被引量:3
19
作者 康冬鹏 廖庆洪 +2 位作者 Ahamd Muhammad Ashfaq 王月媛 刘树田 《Chinese Physics B》 SCIE EI CAS CSCD 2010年第1期318-325,共8页
The entropy squeezing of an atom with a k-photon in the Jaynes Cummings model is investigated. For comparison, we also study the corresponding variance squeezing and atomic inversion. Analytical results show that entr... The entropy squeezing of an atom with a k-photon in the Jaynes Cummings model is investigated. For comparison, we also study the corresponding variance squeezing and atomic inversion. Analytical results show that entropy squeezing is preferable to variance squeezing for zero atomic inversion. Moreover, for initial conditions of the system the relation between squeezing and photon transition number is also discussed. This provides a theoretical approach to finding out the optimal entropy squeezing. 展开更多
关键词 Jaynes-Cumming model entropy squeezing variance squeezing atomic inversion
下载PDF
Entropy squeezing and atomic inversion in the K-photon Jaynes–Cummings model in the presence of the Stark shift and a Kerr medium:A full nonlinear approach 被引量:5
20
作者 H R Baghshahi M K Tavassoly A Behjat 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第7期417-428,共12页
The interaction between a two-level atom and a single-mode field in the k-photon Jaynes-Cummings model (JCM) in the presence of the Stark shift and a Kerr medium is studied. All terms in the Hamiltonian, such as the... The interaction between a two-level atom and a single-mode field in the k-photon Jaynes-Cummings model (JCM) in the presence of the Stark shift and a Kerr medium is studied. All terms in the Hamiltonian, such as the single-mode field, its interaction with the atom, the contribution of the Stark shift and the Kerr medium effects are considered to be f-deformed. In particular, the effect of the initial state of the radiation field on the dynamical evolution of some physical properties such as atomic inversion and entropy squeezing are investigated by considering different initial field states (coherent, squeezed and thermal states). 展开更多
关键词 Jaynes-Cummings model entropy squeezing atomic inversion intensity-dependent coupling
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部