Observation of localized magnetic plasmon skyrmions

Optical skyrmions have recently been constructed by tailoring vectorial near-field distributions through the interference of multiple surface plasmon polaritons, offering promising features for advanced information processing, transport and storage. Here, we provide experimental demonstration of electromagnetic skyrmions based on magnetic localized spoof plasmons (LSP) showing large topological robustness against continuous deformations, without stringent external interference conditions. By directly measuring the spatial profile of all three vectorial magnetic fields, we reveal multiple π-twist target skyrmion configurations mapped to multi-resonant near-equidistant LSP eigenmodes. The real-space skyrmion topology is robust against deformations of the meta-structure, demonstrating flexible skyrmionic textures for arbitrary shapes. The observed magnetic LSP skyrmions pave the way to ultra-compact and robust plasmonic devices, such as flexible sensors, wearable electronics and ultra-compact antennas.

Not Unique, not Universal: Risk Perception and Acceptance of Online Voting Technology by Russian Citizens

What is the connection between Russian citizens' perception of Internet voting and the context of its top down adoption with their readiness to use it? To investigate this question, we use Structural Equation Modeling (SEM) to account for both observed and latent indicators of technology adoption and their linkage with the Internet voting use intent. The authors use survey evidence from VCIOM (2020) and a national survey of Internet users conducted by Online Marketing Intelligence (OMI) company in 2021. This study provides some support to the application of theoretical expectations formulated in the context of Western democracies to the Russian population's voting technology attitudes. The findings indicate that the use of the Internet is not a robust measure of technology acceptance anymore, and a more nuanced approach to the experiences of Internet usage is needed. Internet users appear to be more concerned about privacy, the possibility of fraud, and external interference than the respondents drawn from the overall population. The authors suggest that it is due to acceptance of risks seeming inevitable and to bigger digital literacy and therefore awareness about the risks posed by voting online. Acknowledgments. The authors are grateful to anonymous reviewers for their astute observations and criticism. For their helpful comments, we thank our senior colleagues at HSE University: A. S. Akhremenko, K. L. Marquardt, and M. G. Mironyuk.

Depression and repression: Global capitalism, economic crisis and penal politics in interwar Greece

Notwithstanding the significant advances made over the last twenty years in terms of charting and explaining the ways in which state punishment is influenced by economic and political forces, little is still known about the penal effects of conditions of economic crisis and about the role the incumbent government's political orientation plays in this regard. Because the few available studies on these questions have been preoccupied with the Anglo-American sphere and only in the context of recent decades at that, even less is known either about the implications that different types or experiences of economic crisis carry for state punishment, or about the influence exerted in this respect by government political orientations other than those found in established democracies. Irrespective of geographical or temporal scope, moreover, the impact that different extranational factors and actors may have in terms of economic, political or directly penal matters domestically remains poorly understood. With a view to helping fill these gaps in the literature, this article explores the effects on state punishment that economic crisis and government political orientation had in interaction with one another in the context of interwar Greece. Attention is first paid to various ways in which global capitalism was decisive in creating within Greece an environment conducive to increased punitiveness on the part of the state. The focus is on the economic, social and political consequences of the Wall Street crash of 1929 and Britain's exit from the gold standard in 1931, as these were exacerbated by Greece's long-term exposure to predatory lending, speculative investing and external interference in her domestic affairs in the context of engaging international capital markets. The article then proceeds to discuss how the Liberal government of 1928–1932 sought to handle the situation, particularly the approach it took towards punishment.

The transition from conservative to dissipative flows in class-B laser model with fold-Hopf bifurcation and coexisting attractors

Dynamical behaviors of a class-B laser system with dissipative strength are analyzed for a model in which the polarization is adiabatically eliminated. The results show that the injected signal has an important effect on the dynamical behaviors of the system. When the injected signal is zero, the dissipative term of the class-B laser system is balanced with external interference, and the quasi-periodic flows with conservative phase volume appear. And when the injected signal is not zero, the stable state in the system is broken, and the attractors (period, quasi-period, and chaos) with contractive phase volume are generated. The numerical simulation finds that the system has not only one attractor, but also coexisting phenomena (period and period, period and quasi-period) in special cases. When the injected signal passes the critical value, the class-B laser system has a fold-Hopf bifurcation and exists torus ”blow-up” phenomenon, which will be proved by theoretical analysis and numerical simulation.

Simultaneous Detection of Relative Humidity and Temperature Based on Silicon On-Chip Cascaded Photonic Crystal Nanobeam Cavities

In this paper, we propose and numerically demonstrate a novel cascaded silicon-on-insulator (SOI) photonic crystal nanobeam cavity (PCNC) dual-parameter sensor for the simultaneous detection of relative humidity (RH) and temperature. The structure consists of two independent PCNCs supporting two different resonant modes: a dielectric-mode and an air-mode, respectively. The dielectric-mode nanobeam cavities (cav1) are covered with SU-8 cladding to increase the sensitivity ratio contrast between RH sensing and temperature sensing. The air-mode nanobeam cavities (cav2) are coated with a water-absorbing polyvinyl-alcohol (PVA) layer that converts the change in RH into a change in refractive index (RI) under different ambient RH levels, thereby inducing a wavelength shift. Due to the positive thermo-optic (TO) coefficient of silicon and the negative TO coefficient of SU-8 cladding, the wavelength responses take the form of a red shift for cav2 and a blue shift for cav1 as the ambient temperature increases. By using 3D finite-difference time-domain (3D-FDTD) simulations, we prove the feasibility of simultaneous sensing by monitoring a single output transmission spectrum and applying the sensor matrix. For cav1, the RH and temperature sensitivities are 0 pm/%RH and −37.9 pm/K, while those of cav2 are −389.2 pm/%RH and 58.6 pm/K. The sensitivity ratios of temperature and RH are −1.5 and 0, respectively, which is the reason for designing two different resonant modes and also implies great potential for realizing dual-parameter sensing detection. In particular, it is also noteworthy that we demonstrate the ability of the dual-parameter sensor to resist external interference by using the dual wavelength matrix method. The maximum RH and temperature detection errors caused by the deviation of resonance wavelength 1 pm are only 0.006% RH and 0.026 K, which indicates that it achieves an excellent anti-interference ability. Furthermore, the structure is very compact, occupying only 32 μm × 4 μm (length × width). Hence, the proposed sensor shows promising prospects for compact lab-on-chip integrated sensor arrays and sensing with multiple parameters.

Integrated Fixed Time Sliding Mode Control for Motion and Vibration of Space Robot with Fully Flexible Base–Link–Joint

The dynamic modeling, motion control and flexible vibration active suppression of space robot under the influence of flexible base, flexible link and flexible joint are explored, and motion and vibration integrated fixed-time sliding mode control of fully flexible system is designed. The flexibility of the base and joints are equivalent to the vibration effect of linear springs and torsion springs. The flexible links are regarded as Euler–Bernoulli simply supported beams, which are analyzed by the hypothetical mode method, and the dynamic model of the fully flexible space robot is established by using the Lagrange equation. Then, the singular perturbation theory is used to decompose the model into slow subsystem including rigid motion and the link flexible vibrations, and fast subsystems including the base and the joint flexible vibrations. A fixed time sliding mode control based on hybrid trajectory is designed for the slow subsystem to ensure that the base and joints track the desired trajectory in a limited time while achieving vibration suppression on the flexible links. For the fast subsystem, linear quadratic optimal control is used to suppress the flexible vibration of the base and joints. The simulation results show that the controller proposed in the paper can make the system state converge within a fixed time, is robust to model uncertainty and external interference, and can effectively suppress the flexible vibration of the base, links, and joints.

Research on high-speed railway operation adjustment model based on priority

Purpose This paper aim at providing decision support for operational adjustment. In order to effectively reduce the external interference impact on train operation. Design/methodology/approach According to the reality that there are two kinds of high-speed trains running in China, considering the reality that there are two speed level train running in Chinese high-speed railway, this paper proposed the high-speed railway operation adjustment model based on priority, and the objective function is to minimize interference impact on train operation. Findings Adjustment strategy based on priority than based on sequence can effectively reduce the interference influence on train operation, which makes the train resume the planned operation back on schedule more quickly. Research limitations/implications The solution of large-scale cases is too slow, and the practical application is limited. Originality/value The model was verified by a case, and the case results proved that adjustment strategy based on priority than based on sequence can effectively reduce the interference influence on train operation, which makes the train resume the planned operation back on schedule more quickly.

Application of Traditional Graphic Elements Based on Fiber Bragg Grating Tactile Sensor Technology

In today’s era, sensing technology has been very developed in the fields of machinery, medicine, safety monitoring, and so on. In order to be applicable to more fields, new sensing technologies are also evolving. Tactile and sensory states are two important indicators of human induction to external things. Based on the contact force information between fiber Bragg grating tactile sensor and human body, this paper uses a new fiber Bragg grating tactile sensing system to study the artistic elements of ink painting in modern graphic design. Subsequently, the structure and specific performances of the sensor experimental data are analyzed. With its small volume, low cost, high sensitivity, and good compatibility with the observed body, the new fiber Bragg grating tactile sensor will not be affected by external electromagnetic interference, various noise signals, complex integration, and other problems. According to the data observed by ink painters in this paper, the new tactile sensing technology of fiber Bragg grating can well control the external interference factors. In general, the technology is of great social and practical value.