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1.
Clear windows onto emergent hadron mass(EHM)and modulations thereof by Higgs boson interactions are provided by observable measures of pion and kaon structure,many of which are accessible via generalised parton distributions(GPDs).Beginning with algebraic GPD Ans?tze,constrained entirely by hadron-scaleπand K valence-parton distribution functions(DFs),in whose forms both EHM and Higgs boson influences are manifest,numerous illustrations are provided.They include the properties of electromagnetic form factors,impact parameter space GPDs,gravitational form factors and associated pressure profiles,and the character and consequences of allorders evolution.The analyses predict that mass-squared gravitational form factors are stiffer than electromagnetic form factors;reveal that K pressure profiles are tighter than profiles,with both mesons sustaining near-core pressures at magnitudes similar to that expected at the core of neutron stars;deliver parameter-free predictions for and K valence,glue,and sea GPDs at the resolving scale l=2GeV;and predict that at this scale the fraction of meson mass-squared carried by glue and sea combined matches that lodged with the valence degrees-of-freedom,with a similar statement holding for mass-squared radii.  相似文献   

2.
The subsolidus phase relations of a ZnO-V 2 O 5-K 2 O system are investigated by X-ray powder diffraction.There is 1 ternary compound,11 binary compounds and 14 three-phase regions in this system.The phase diagrams of V 2 O 5 K 2 O with the K 2 O content ranging from 0 to 71 mol% and pseudo-binary system of ZnO-K 2 ZnV 2 O 7 are also studied by X-ray powder diffraction and differential thermal analysis methods.  相似文献   

3.
Optical fibers are seen in the optical sensing and optical fiber communication. Simultaneous propagation of optical pulses in an inhomogeneous optical fiber is described by a coupled time-dependent coefficient fourth-order nonlinear Schr?dinger system, which is discussed in this paper. For such a system, we work out the Lax pair, Darboux transformation, and corresponding vector semi-rational nonautonomous rogue wave solutions. When the group velocity dispersion(GVD) and fourth-order dispersion(FOD) coefficients are the constants, we exhibit the first-and second-order vector semirational rogue waves which are composed of the four-petalled rogue waves and eye-shaped breathers. Both the width of the rogue wave along the time axis and temporal separation between the adjacent peaks of the breather decrease with the GVD coefficient or FOD coefficient. With the GVD and FOD coefficients as the linear, cosine, and exponential functions, we respectively present the first-and second-order periodic vector semi-rational rogue waves, first-and second-order asymmetry vector semi-rational rogue waves, and interactions between the eye-shaped breathers and the composite rogue waves.  相似文献   

4.
Gamal G.L.Nashed 《中国物理 B》2012,21(6):60401-060401
A perfect fluid with self-similarity of the second kind is studied within the framework of the teleparallel equivalent of general relativity(TEGR).A spacetime which is not asymptotically flat is derived.The energy conditions of this spacetime are studied.It is shown that after some time the strong energy condition is not enough to satisfy showing a transition from standard matter to dark energy.The singularities of this solution are discussed.  相似文献   

5.
乔明  庄翔  吴丽娟  章文通  温恒娟  张波  李肇基 《中国物理 B》2012,21(10):108502-108502
Based on the theoretical and experimental investigation of a thin silicon layer(TSL) with linear variable doping(LVD) and further research on the TSL LVD with a multiple step field plate(MSFP),a breakdown voltage(BV) model is proposed and experimentally verified in this paper.With the two-dimensional Poisson equation of the silicon on insulator(SOI) device,the lateral electric field in drift region of the thin silicon layer is assumed to be constant.For the SOI device with LVD in the thin silicon layer,the dependence of the BV on impurity concentration under the drain is investigated by an enhanced dielectric layer field(ENDIF),from which the reduced surface field(RESURF) condition is deduced.The drain in the centre of the device has a good self-isolation effect,but the problem of the high voltage interconnection(HVI) line will become serious.The two step field plates including the source field plate and gate field plate can be adopted to shield the HVI adverse effect on the device.Based on this model,the TSL LVD SOI n-channel lateral double-diffused MOSFET(nLDMOS) with MSFP is realized.The experimental breakdown voltage(BV) and specific on-resistance(R on,sp) of the TSL LVD SOI device are 694 V and 21.3 ·mm 2 with a drift region length of 60 μm,buried oxide layer of 3 μm,and silicon layer of 0.15 μm,respectively.  相似文献   

6.
王月媛  刘正君  廖庆洪  刘树田 《中国物理 B》2010,19(5):54204-054204
Phase properties of the even and odd circular states are studied within the Hermitian phase formalism of Pegg and Barnett. Exact analytical formulas for the distribution function and the variance of the phase operator are obtained and used to examine whether or not the even and odd circular states exhibit photon-number squeezing and phase squeezing.  相似文献   

7.
程玉民  王健菲  白福浓 《中国物理 B》2012,21(9):90203-090203
In this paper, based on the element-free Galerkin (EFG) method and the improved complex variable moving least- square (ICVMLS) approximation, a new meshless method, which is the improved complex variable element-free Galerkin (ICVEFG) method for two-dimensional potential problems, is presented. In the method, the integral weak form of control equations is employed, and the Lagrange multiplier is used to apply the essential boundary conditions. Then the corresponding formulas of the ICVEFG method for two-dimensional potential problems are obtained. Compared with the complex variable moving least-square (CVMLS) approximation proposed by Cheng, the functional in the ICVMLS approximation has an explicit physical meaning. Furthermore, the ICVEFG method has greater computational precision and efficiency. Three numerical examples are given to show the validity of the proposed method.  相似文献   

8.
The quantum private query(QPQ)is a quantum solution for the symmetrically private information retrieval problem.We study the security of quantum-key-distribution-based QPQ with weak coherent pulses.The result shows that multiphoton pulses have posed a serious threat to the participant’s privacy in QPQ protocols.Then we propose a decoy-state method that can help the honest participant detect the attack by exploiting multiphoton pulses and improving the key distillation process to defend against such attack.The analysis demonstrates that our decoy-state method significantly improves the security of the QPQ with weak coherent pulses,which solves a major obstacle in the practical application of the QPQ.  相似文献   

9.
The spin structure of nucleons is presented in the framework of an extended quark model which in addition to the conventional qqq structure also takes into account qqqq admixtures in the nucleon wave functions, where the qqqq components are in colored quark cluster configurations. The axial vector weak coupling constant and spin distributions for polarized nucleons as well as spin content are obtained for the lowest positive parity qqqq configurations in flavor-spin dependent interaction. In particular, the contributions of the down and strange quarks to the proton spin and the sum rule for polarized neutron are negative, in agreement with recent experiments.  相似文献   

10.
With the help of a modified mapping method,we obtain two kinds of variable separation solutions with two arbitrary functions for the(2+1)-dimensional dispersive long wave equation.When selecting appropriate multi-valued functions in the variable separation solution,we investigate the interactions among special multi-dromions,dromion-like multi-peakons,and dromion-like multi-semifoldons,which all demonstrate non-completely elastic properties.  相似文献   

11.
黄国勇  姜长生  王玉惠 《物理学报》2007,56(11):6224-6229
针对一类不确定混沌系统设计了基于快速模糊干扰观测器的鲁棒terminal滑模控制方案.首先通过设计快速模糊干扰观测器,克服了传统模糊干扰观测器在误差较小时收敛速度慢的缺点.然后严格证明了在存在未知干扰和不确定的情况下,同步误差及观测器误差均在有限时间内收敛到非常小的区域.最后对Duffing-Holmes混沌系统进行仿真,结果表明了所设计干扰观测器的优越性和闭环控制方案的有效性.  相似文献   

12.
基于观测器的混沌系统的同步研究   总被引:9,自引:1,他引:9       下载免费PDF全文
提出了一类混沌系统的观测器同步方法.利用混沌系统的状态观测器,给出了一类混沌系统 观测器的同步的简单有效的方法,并分析了系统的稳定性,通过对Lorenz混沌系统的分析和 数值模拟研究,验证了该方法在混沌同步中的优良性能. 关键词: 混沌系统 混沌同步 状态观测器  相似文献   

13.
谢林柏  周志刚  张正道 《物理学报》2013,62(18):188702-188702
在混沌系统的同步控制中, 由于混沌系统对初始状态的敏感性, 一旦两个混沌系统的状态初值偏差大, 其状态同步往往需要高幅值的控制律来达到, 这给同步控制实现带来了困难, 并且在同步控制中, 两个混沌系统的初始值通常是未知的. 本文考虑控制输入受限情况下的混沌同步控制问题, 基于符号函数的近似表示式, 将受限的控制输入建模为连续可微的光滑函数, 在每一个采样点将同步控制误差系统近似为局部最优线性模型并设计连续型线性二次型调节器(LQR)最优控制律. 为降低混沌同步控制律的幅值和维持同步系统采样时刻之间的动态, 设计了等价的离散最优控制律, 并通过调整LQR性能加权矩阵值, 确保同步控制信号不会超出其受限的上界. 最后对统一混沌模型下的三种不同混沌系统同步控制进行了仿真研究. 仿真结果验证了方法的有效性. 关键词: 统一混沌模型 符号函数 输入受限 同步控制  相似文献   

14.
一种参数摄动的混沌异结构同步方法   总被引:1,自引:0,他引:1       下载免费PDF全文
韩敏  牛志强  韩冰 《物理学报》2008,57(11):6824-6829
研究了参数摄动情形下的混沌异结构同步问题,基于Lyapunov稳定性定理并结合范数理论给出了系统参数摄动下实现混沌异结构同步的一个充分条件,为同步控制器的设计提供了一般方法.只要两混沌系统维数相等,状态变量可测,就可利用所提方法实现系统参数摄动下的异结构同步,并能够保证在同步实现后同步控制量伴随误差变量一同收敛至零.该方法鲁棒性强,适用范围广,通过对混沌系统、超混沌系统的同步仿真,证实了该方法的有效性. 关键词: 混沌 超混沌 同步 Lyapunov函数  相似文献   

15.
一类带有未知参数的受扰混沌系统的观测器同步   总被引:2,自引:0,他引:2       下载免费PDF全文
李秀春  谷建华  王云岚  赵天海 《物理学报》2011,60(3):30505-030505
在系统参数未知的情形下,观测器方法和自适应方法相结合,实现了一类受扰混沌系统的同步.借助于Lyapunov稳定性理论和Barbalat引理,给出了观测器的设计方法.此方法约束条件较少,适应于大部分常见的混沌系统.最后,通过对典型混沌系统的同步数值仿真,证实了方法的有效性和正确性. 关键词: 混沌系统 外界干扰 同步 观测器法  相似文献   

16.
付士慧  陆启韶  杜莹 《中国物理 B》2012,21(6):60507-060507
Adaptive H∞ synchronization of chaotic systems via linear and nonlinear feedback control is investigated.The chaotic systems are redesigned by using the generalized Hamiltonian systems and observer approach.Based on Lyapunov’s stability theory,linear and nonlinear feedback control of adaptive H∞ synchronization is established in order to not only guarantee stable synchronization of both master and slave systems but also reduce the effect of external disturbance on an H∞-norm constraint.Adaptive H∞ synchronization of chaotic systems via three kinds of control is investigated with applications to Lorenz and Chen systems.Numerical simulations are also given to identify theeffectiveness of the theoretical analysis.  相似文献   

17.
This paper considers the adaptive synchronization problem of the drive—response type chaotic systems. Using a transmitted scalar signal with an unknown time-delay, a response system is constructed. By appropriately selecting the observer gain and designing the controller, synchronization can be achieved in the presence of the drive system's disturbances and unknown parameters. A well-known chaotic system, Chua's circuit, is considered as an illustrative example to demonstrate the effectiveness of the proposed approach.  相似文献   

18.
陈晶  张天平 《物理学报》2006,55(8):3928-3932
基于降维观测器的方法实现了一类具有外部扰动的混沌系统的同步. 无需知道系统外部扰动项的任何信息,就可对驱动系统设计基于降维观测器的响应系统,从而实现了混沌系统的同步. 数值仿真表明该方法是有效的. 关键词: 混沌同步 混沌系统 观测器  相似文献   

19.
Hénon混沌系统的广义预测控制与同步快速算法   总被引:5,自引:0,他引:5       下载免费PDF全文
刘福才  梁晓明 《物理学报》2005,54(10):4584-4589
提出了一种带有终端滑模等式约束的Hénon混沌系统的广义预测控制快速算法.该方法将广义预测控制与离散滑模控制结合起来运用到Hénon混沌系统中,并采用柔化输入信号的方法,避免了广义预测控制算法中的高维矩阵求逆.占用内存小,计算速度快,并且具有较强的跟踪给定信号和抑制系统参数摄动和随机噪声的能力.仿真结果验证了该方法的有效性和快速性. 关键词: 广义预测控制 离散滑模控制 Hénon混沌系统 混沌同步  相似文献   

20.
扰动情况下一类混沌系统的观测器同步   总被引:13,自引:3,他引:10       下载免费PDF全文
研究了存在外界扰动情况下一类混沌系统的同步问题,混沌系统非线性项无需满足输出反馈形式.首先对系统进行变换得到未受扰降价混沌系统,然后基于非线性观测器的思想构造同步观测系统实现了混沌同步,通过仿真证实了该方法的有效性. 关键词: 混沌系统 同步 观测器  相似文献   

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