Complete-basis-reprogrammable coding metasurface for generating dynamicallycontrolled holograms under arbitrary polarization states

Reprogrammable metasurfaces,which establish a fascinating bridge between physical and information domains,can dynamically control electromagnetic(EM)waves in real time and thus have attracted great attentions from researchers around the world.To control EM waves with an arbitrary polarization state,it is desirable that a complete set of basis states be controlled independently since incident EM waves with an arbitrary polarization state can be decomposed as a linear sum of these basis states.In this work,we present the concept of complete-basis-reprogrammable coding metasurface(CBR-CM)in reflective manners,which can achieve independently dynamic controls over the reflection phases while maintaining the same amplitude for left-handed circularly polarized(LCP)waves and right-handed circularly polarized(RCP)waves.Since LCP and RCP waves together constitute a complete basis set of planar EM waves,dynamicallycontrolled holograms can be generated under arbitrarily polarized wave incidence.The dynamically reconfigurable metaparticle is implemented to demonstrate the CBR-CM’s robust capability of controlling the longitudinal and transverse positions of holograms under LCP and RCP waves independently.It’s expected that the proposed CBR-CM opens up ways of realizing more sophisticated and advanced devices with multiple independent information channels,which may provide technical assistance for digital EM environment reproduction.

Natural frequency analysis of laminated piezoelectric beams with arbitrary polarization directions

Piezoelectric devices exhibit unique properties that vary with different vibration modes,closely influenced by their polarization direction.This paper presents an analysis on the free vibration of laminated piezoelectric beams with varying polarization directions,using a state-space-based differential quadrature method.First,based on the electro-elasticity theory,the state-space method is extended to anisotropic piezoelectric materials,establishing state-space equations for arbitrary polarized piezoelectric beams.A semi-analytical solution for the natural frequency is then obtained via the differential quadrature method.The study commences by examining the impact of a uniform polarization direction,and then proceeds to analyze six polarization schemes relevant to the current research and applications.Additionally,the effects of geometric dimensions and gradient index on the natural frequencies are explored.The numerical results demonstrate that varying the polarization direction can significantly influence the natural frequencies,offering distinct advantages for piezoelectric elements with different polarizations.This research provides both theoretical insights and numerical methods for the structural design of piezoelectric devices.

Least Square Finite Element Model for Analysis of Multilayered Composite Plates under Arbitrary Boundary Conditions

Laminated composites are widely used in many engineering industries such as aircraft, spacecraft, boat hulls, racing car bodies, and storage tanks. We analyze the 3D deformations of a multilayered, linear elastic, anisotropic rectangular plate subjected to arbitrary boundary conditions on one edge and simply supported on other edge. The rectangular laminate consists of anisotropic and homogeneous laminae of arbitrary thicknesses. This study presents the elastic analysis of laminated composite plates subjected to sinusoidal mechanical loading under arbitrary boundary conditions. Least square finite element solutions for displacements and stresses are investigated using a mathematical model, called a state-space model, which allows us to simultaneously solve for these field variables in the composite structure’s domain and ensure that continuity conditions are satisfied at layer interfaces. The governing equations are derived from this model using a numerical technique called the least-squares finite element method (LSFEM). These LSFEMs seek to minimize the squares of the governing equations and the associated side conditions residuals over the computational domain. The model is comprised of layerwise variables such as displacements, out-of-plane stresses, and in- plane strains, treated as independent variables. Numerical results are presented to demonstrate the response of the laminated composite plates under various arbitrary boundary conditions using LSFEM and compared with the 3D elasticity solution available in the literature.

基于任意四边形拟合的轨道分割算法

精准高效地完成轨道分割与障碍物检测对于智能行车具有重要意义。现有深度学习算法对轨道区域分割与障碍物识别区分不明确,复杂区域极易出现多轨融合、识别率低等情况。为此,提出一种基于任意四边形拟合的轨道分割框架,实现轨道分割任务;将其嵌入YOLOv5网络中,设计出一种全新的轨道交通双视觉任务网络(YOLOv5-DVT),该网络可根据轨道的不同特征,使用任意四边形切分轨道;经过多边形角点排序、自适应正样本匹配、相对重心位置编解码及顺序预测约束等环节完成对任意四边形轨道的预测,利用多边形寻迹拟合算法实现对轨道区域的恢复与分割;通过设计双任务结构,采用端到端的轨道分割与障碍物检测并行训练策略实现同步分割与障碍物识别,提升推理速度。采用自建数据集对该算法进行验证,试验结果表明:与经典分割算法相比,本文方法在复杂轨道的分割中更加清晰准确,其双任务精度分别达到95.10%、93.51%,推理速度达32 FPS,具备实际场景的应用价值。

用于可控电穿孔的分布式任意波形高压脉冲电源研制

针对电穿孔研究与应用对于特殊脉冲波形的需求,本文基于全桥逆变结构的双极性全固态Marx拓扑,提出了一种由多个标准脉冲功率模块组成的分布式任意波形高压脉冲电源。每个标准模块均包含完整的主电路、驱动电路以及控制电路,且内置了通信协议,具有单模块独立工作与多模块组合协同工作等多种工作模式。通过对模块中不同开关的状态进行控制,可以实现任意高压脉冲波形的输出。基于电源-负载匹配分析了关键器件参数对输出的影响,搭建了电源的拓扑仿真模型,验证了其正确性与可行性。在此基础上研制了可输出±8 kV、33阶电平任意波形的实验样机,并搭建出微藻电穿孔实验平台。在控制脉冲电压幅值为8kV、能量为0.4 J条件下进行多种波形的微藻电穿孔实验充分论证了该分布式电源在可控电穿孔领域的适用性。

一类具有任意初始能量的含对数非线性源分数阶p-Laplace抛物方程

本文研究一类具有对数非线性源的分数阶p-Laplace抛物方程的初边值问题.在亚临界初始能量条件下,利用凸方法证明了解在有限时刻爆破;在临界初始能量条件下,通过研究原方程的近似问题得到了整体解的存在性并建立了L^(2)范数的衰减估计;在超临界初始能量条件下,给出了全局解和爆破解的充分条件.

Optimized nonhyperbolic moveout correction equation of long-offset seismic data for TI media with an arbitrary spatial orientation

The conventional long-offset nonhyperbolic moveout equation is derived for the transverse isotropic media with a vertical symmetric axis（VTI）.It cannot be extended to the transverse isotropic media with an arbitrary spatial orientation of symmetry axis（ATI）.In this paper,we optimize a modified long-offset nonhyperbolic moveout equation for ATI media based on the conventional nonhyperbolic moveout equation and the exact analytical solution of the quartic moveout coefficient（A_4） and NMO velocity for ATI media that were derived in our previous work.Compared with the exact traveltimes of the ray-tracing algorithm for anisotropic media,this optimized equation can be used to calculate the traveltime varying with survey line azimuth in arbitrary strong or weak ATI media.It can replace the time-consuming, multi-offset,and multi-azimuth ray tracing method for forward modeling of long-offset reflection traveltimes in ATI media,which is useful to further anisotropic parameter inversion using long-offset nonhyperbolic moveout.

基于符号执行的权限控制和转账漏洞检测方法

针对权限控制漏洞和任意转账漏洞会让用户遭受经济损失的问题,提出一种基于符号执行的权限控制漏洞和任意转账漏洞检测方法。总结漏洞特征,设计漏洞检测算法,利用符号执行构建交易路径,通过漏洞特征构建约束条件并求解,实现工具PTGuard。实验结果表明,PTGuard的准确率、精确率、召回率和F1值相比其它漏洞检测工具有较大的提升;PTGuard已应用于科技部国家重点项目,挖掘出17个漏洞,已成功上报到国家共享漏洞数据库,验证了PTGuard的实际应用价值。

基于ALE-ANCF方法的卷曲展开机构动力学建模与分析

针对含复杂的多区域接触的卷曲展开机构,该研究将其简化为带刚性转盘的变长度柔性构件,建立多体系统动力学模型,以实现高效仿真。首先,基于任意拉格朗日-欧拉描述的绝对节点坐标法对变长度梁进行建模;然后,将复杂接触问题简化为移动边界的约束关系,给出一种增删节点处理方法,有效解决了单元长度变化引起的奇异和精度问题,在此基础上建立了刚-柔耦合多体系统的动力学模型,用隐式算法实现了动力学方程的数值求解。通过滑绳和动滑轮算例验证了建模方法的有效性;最后,建立了卷曲机构充气展开系统的简化动力学模型,该模型采用任意拉格朗日-欧拉法移动网格实时跟踪卷曲机构的位置,精准捕捉移动边界点,从而高效确定接触行为。分析了气压力与黏附力对展开动力学特性的影响,通过控制黏附力分布,实现了卷曲机构的匀速展开,对工程实际具有参考价值。

生命政治视域下马克思与阿甘本“自由人”主体的反思与建构

对人类自由而全面发展的价值诉求,是勾连马克思“自由人”理论与当代生命政治学主体理论的共同之点。生命政治的历史出场与当代发展,延续马克思对资本主义剥削实质的批判主题,延展马克思对资本主义当代形态的时代边界。马克思以历史唯物主义和政治经济学批判得出“自由人”本质为“劳动人”(homo faber),意大利左翼学者吉乔奥·阿甘本以“任意的独体”等主体性概念,开辟出西方左翼将“自由人”理解为“政治人”(homo politics)的理论路向。传统与激进主体方案的理论差异,既源于马克思“实践历史观”与阿甘本“断裂历史观”的分歧对峙,也关乎对亚里士多德与黑格尔自由观的不同借鉴。通过“以马解甘”和“以甘解马”的双重视角,突出马克思与阿甘本虽然在目标旨趣、理论背景和建构方案上存在具体差异性,但能够在“宏观主体历史科学”与“微观主体政治哲学”之间产生有效的时代对话。

基于神经网络与注意力的任意图像风格迁移研究综述

随着神经网络的广泛应用,尤其是注意力机制的引入,风格迁移研究取得了显著进展。文章对基于卷积神经网络、注意力机制的图像风格迁移进行了综述。首先,分析了风格迁移的基本原理和传统方法,详细介绍了基于深度学习的风格迁移算法,尤其聚焦于那些通过引入注意力机制来强化模型风格表现与内容保持能力的创新方法。其次,通过比较不同算法的性能,探讨了现有方法在局部内容保留和风格控制精度方面的优点与缺点。最后,分析了任意图像风格迁移领域的发展趋势和潜在的研究方向。

Three-dimensional arbitrarily anisotropic modeling for time-domain airborne electromagnetic surveys

Electrically anisotropic strata are abundant in nature, so their study can help our data interpretation and our understanding of the processes of geodynamics. However, current data processing generally assumes isotropic conditions when surveying anisotropic structures, which may cause discrepancies between reality and electromagnetic data interpretation. Moreover, the anisotropic interpretation of the time-domain airborne electromagnetic （TDAEM） method is still confined to one dimensional （1D） cases, and the corresponding three-dimensional （3D） numerical simulations are still in development. In this study, we expanded the 3D TDAEM modeling of arbitrarily anisotropic media. First, through coordinate rotation of isotropic conductivity, we obtained the conductivity tensor of an arbitrary anisotropic rock. Next, we incorporated this into Maxwell＇s equations, using a regular hexahedral grid of vector finite elements to subdivide the solution area. A direct solver software package provided the solution for the sparse linear equations that resulted. Analytical solutions were used to verify the accuracy and feasibility of the algorithm. The proven model was then applied to analyze the effects of arbitrary anisotropy in 3D TDAEM via the distribution of responses and amplitude changes, which revealed that different anisotropy situations strongly affected the responses of TDAEM.

High-Order Models of Nonlinear and Dispersive Wave in Water of Varying Depth with Arbitrary Sloping Bottom

High-order models with a dissipative term for nonlinear and dispersive wave in water of varying depth with an arbitrary sloping bottom are presented in this article. First, the formal derivations to any high order of mu(= h/lambda, depth to deep-water wave length ratio) and epsilon(= a/h, wave amplitude to depth ratio) for velocity potential, particle velocity vector, pressure and the Boussinesq-type equations for surface elevation eta and horizontal velocity vector (U) over right arrow at any given level in water are given. Then, the exact explicit expressions to the fourth order of mu are derived. Finally, the linear solutions of eta, (U) over right arrow, C (phase-celerity) and C-g (group velocity) for a constant water depth are obtained. Compared with the Airy theory, excellent results can be found even for a water depth as large as the wave legnth. The present high-order models are applicable to nonlinear regular and irregular waves in water of any varying depth (from shallow to deep) and bottom slope (from mild to steep).

Computing Streamfunction and Velocity Potential in a Limited Domain of Arbitrary Shape.Part I:Theory and Integral Formulae

The non-uniqueness of solution and compatibility between the coupled boundary conditions in computing velocity potential and streamfunction from horizontal velocity in a limited domain of arbitrary shape are revisited theoretically with rigorous mathematic treatments.Classic integral formulas and their variants are used to formulate solutions for the coupled problems.In the absence of data holes,the total solution is the sum of two integral solutions.One is the internally induced solution produced purely and uniquely by the domain internal divergence and vorticity,and its two components（velocity potential and streamfunction） can be constructed by applying Green＇s function for Poisson equation in unbounded domain to the divergence and vorticity inside the domain.The other is the externally induced solution produced purely but non-uniquely by the domain external divergence and vorticity,and the non-uniqueness is caused by the harmonic nature of the solution and the unknown divergence and vorticity distributions outside the domain.By setting either the velocity potential（or streamfunction） component to zero,the other component of the externally induced solution can be expressed by the imaginary（or real） part of the Cauchy integral constructed using the coupled boundary conditions and solvability conditions that exclude the internally induced solution.The streamfunction（or velocity potential） for the externally induced solution can also be expressed by the boundary integral of a double-layer（or singlelayer） density function.In the presence of data holes,the total solution includes a data-hole-induced solution in addition to the above internally and externally induced solutions.

Probabilistic teleportation of an arbitrary three-particle state

A scheme for teleporting an arbitrary and unknown three-particle state from a sender to either one of two receivers is proposed. The quantum channel is composed of a two-particle non-maximally entangled state and two three-particle non-maximally entangled W states. An arbitrary three-particle state can be perfectly teleported probabilistically if the sender performs three generalized Bell-state measurements and sends to the two receivers the classical result of these measurements, and either one of the two receivers adopts an appropriate unitary transformation conditioned on the suitable measurement outcomes of the other receiver. All kinds of unitary transformations are given in detail.

The scattering fields for a spherical target irradiated by a plane electromagnetic wave in an arbitrary direction

The relation between corresponding trigonometric functions in two rotating coordinate systems is presented. The transformation formula for a vector in the two rotating spherical coordinate systems is obtained. The scattering fields for a spherical target irradiated by a plane electromagnetic wave in an arbitrary direction are derived. These fields in a particular case retrogress to those available in the literature. The obtained results have great potential in practical applications.

A new representation and probabilistic teleportation of an arbitrary and unknown N-particle state

A new representation of an arbitrary and unknown N-particle state is presented at first. As an application, a scheme for teleporting an arbitrary and unknown N-particle state is proposed when N pairs of two-particle non- maximally entangled states are utilized as quantum channels. After Alice （sender） makes Bell-state measurement on her particles, Bob （recipient） introduces an auxiliary particle and carries out appropriate unitary transformation on his particle and the auxiliary particle depending on classical information from Alice. Then, von Neumann measurement that confirms whether the teleportation succeeds or not is performed by Bob on the auxiliary particle. In order to complete the teleportation, another N-1 times operations need to be performed which are similar to the above ones. It can be successfully realized with a certain probability which is determined by the product of the smaller coefficients of non-maximally entangled pairs. All possible unitary transformations are given in detail.

Computing Streamfunction and Velocity Potential in a Limited Domain of Arbitrary Shape.Part II:Numerical Methods and Test Experiments

Built on the integral formulas in Part I,numerical methods are developed for computing velocity potential and streamfunction in a limited domain.When there is no inner boundary（around a data hole） inside the domain,the total solution is the sum of the internally and externally induced parts.For the internally induced part,three numerical schemes（grid-staggering,local-nesting and piecewise continuous integration） are designed to deal with the singularity of the Green＇s function encountered in numerical calculations.For the externally induced part,by setting the velocity potential（or streamfunction） component to zero,the other component of the solution can be computed in two ways：（1） Solve for the density function from its boundary integral equation and then construct the solution from the boundary integral of the density function.（2） Use the Cauchy integral to construct the solution directly.The boundary integral can be discretized on a uniform grid along the boundary.By using local-nesting（or piecewise continuous integration）,the scheme is refined to enhance the discretization accuracy of the boundary integral around each corner point（or along the entire boundary）.When the domain is not free of data holes,the total solution contains a data-hole-induced part,and the Cauchy integral method is extended to construct the externally induced solution with irregular external and internal boundaries.An automated algorithm is designed to facilitate the integrations along the irregular external and internal boundaries.Numerical experiments are performed to evaluate the accuracy and efficiency of each scheme relative to others.

Probabilistic Teleportation of an Arbitrary Two-particle State

A scheme for the teleportation of an arbitrary two-particle state via two non-maximally entangled particle pairsis proposed. We show that teleportation can be successfully realized with a certain probability if the receiveradopts an appropriate unitary-reduction strategy. A specific strategy is provided in detail The probability of successful teleportation is determined by the smaller coefficients of the two entangled pairs.

Probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel and its application in quantum state sharing

This paper presents a scheme for probabilistic teleportation of an arbitrary GHZ-class state with a pure entangled two-particle quantum channel. The sender Alice first teleports the coefficients of the unknown state to the receiver Bob, and then Bob reconstructs the state with an auxiliary particle and some unitary operations if the teleportation succeeds. This scheme has the advantage of transmitting much less particles for teleporting an arbitrary GHZ-class state than others. Moreover, it discusses the application of this scheme in quantum state sharing.