We use the Chern–Simons action for a 𝕊𝕆(3)-connection for the description of point disclinations in the geometric theory of defects. The most general spherically symmetric 𝕊𝕆(3)-connection with zero curvature is found. The corresponding orthogonal spherically symmetric 𝕊𝕆(3) matrix and n-field are computed. Two examples of point disclinations are described.

Poisson’s ratios of two-dimensional (2D) all-inorganic perovskites Cs2PbX4 (X = Cl, Br, I) have been calculated by the first-principles calculations. The contribution of each geometric parameter (bond length L, bond angle Φ, rotation angle 𝜃1, and tilt angle 𝜃2) to Poisson’s ratio is obtained analytically. Through a comprehensive analysis of the geometric deformations of the perovskite under the

The directed transport of inertial Lévy flights resulting from the superimposed roughness in a corrugated potential is investigated in this paper. The influence of the roughness on the transport is studied by calculating the mean velocity (MV) and the mean first escape time (MFET), with respect to the Lévy index μ and the asymmetry parameter q which determines the asymmetry of the potential. The results

The Andreev conductance in Δ-shaped quantum dots (QDs) system coupled with Majorana bound states (MBSs) is studied and resulting conductance spectrum displays resonant and non-resonant processes. These fluctuated resonances render features like insulating band, bonding (antibonding) in the low-bias region due to non-trivial role of interdot coupling tc and dots-MBSs coupling λ. On comparing QD levels

Thermodynamic functions of the thermal expansion (αp), isothermal compressibility (κT) and the difference in the heat capacity (Cp−Cv) are calculated as a function of temperature (P=18 GPa) close to the transitions of 𝜀–δloc and δloc–δ in the solid nitrogen. This calculation is performed by using the observed Raman frequency shifts of vibrons (υ1,υ2 and υ22). Also, by using the observed V–P data,

Using first-principles calculations, we investigate the structural, electronic, thermal and optical properties of hexagonal ScAl3C3-type structure LaCd3P3 under high pressure. By calculating elastic constant, the mechanical stability of LaCd3P3 at high pressures was discussed. Then, by calculating the band gap and density of states, the pressure effect on electronic properties of LaCd3P3 was discussed

High-performance integrated electro-optic modulators operating at low temperature are critical for optical interconnects in cryogenic applications. Existing integrated modulators, however, suffer from reduced modulation efficiency or bandwidth at low temperatures because they rely on tuning mechanisms that degrade with decreasing temperature. Graphene modulators are a promising alternative because

Topological photonics has emerged as a novel paradigm for the design of electromagnetic systems from microwaves to nanophotonics. Studies to date have largely focused on the demonstration of fundamental concepts, such as nonreciprocity and waveguiding protected against fabrication disorder. Moving forward, there is a pressing need to identify applications where topological designs can lead to useful

Laser threshold magnetometry using the negatively charged nitrogen-vacancy (NV−) centre in diamond as a gain medium has been proposed as a technique to dramatically enhance the sensitivity of room-temperature magnetometry. We experimentally explore a diamond-loaded open tunable fibre-cavity system as a potential contender for the realisation of lasing with NV− centres. We observe amplification of the

Diamond has attracted great interest as an appealing material for various applications ranging from classical to quantum optics. To date, Raman lasers, single photon sources, quantum sensing and quantum communication have been demonstrated with integrated diamond devices. However, studies of the nonlinear optical properties of diamond have been limited, especially at the nanoscale. Here, a metasurface

We report a homogeneous quantum cascade laser (QCL) emitting at terahertz (THz) frequencies, with a total spectral emission of about 0.6 THz, centered around 3.3 THz, a current density dynamic range Jdr = 1.53, and a continuous wave output power of 7 mW. The analysis of the intermode beatnote unveils that the devised laser operates as an optical frequency comb (FC) synthesizer over the whole laser

Parity-time (PT) symmetry has attracted intensive research interest in recent years. PT symmetry is conventionally implemented between two spatially distributed subspaces with identical localized eigenfrequencies and complementary gain and loss coefficients. The implementation is complicated. In this paper, we propose and demonstrate that PT symmetry can be implemented between two subspaces in a single

This article presents the effect of fiber Bragg gratings side lobes on interrogation systems consisting of sensor and matched filters. The conducted research shows that high-value side lobe structures applied as sensors and/or filters are characterized by some interesting properties. The paper presents both numerical analysis and experimental verification of the fiber Bragg gratings (FBG) interrogation

This paper presents a specifically designed grating-corner-cube sensor for precise roll angle measurements. Owing to the diffraction characteristics of the transmission grating and reflection characteristics of the corner cube, two spatially separated parallel beams are naturally constructed. Through differential detection of the positions of two parallel beams, we experimentally demonstrate the possibility

In the last decade, Raman Spectroscopy (RS) was demonstrated to be a label-free, non-invasive and non-destructive optical spectroscopy allowing the improvement in diagnostic accuracy in cancer and analytical assessment for cell sensing. This review discusses how Raman spectra can lead to a deeper molecular understanding of the biochemical changes in cancer cells in comparison to non-cancer cells, analyzing

Coal and gas outbursts are among the most severe disasters threatening the safety of coal mines around the world. They are dynamic phenomena characterized by large quantities of coal and gas ejected from working faces within a short time. Numerous researchers have conducted studies on outburst prediction, and a variety of indices have been developed to this end. However, these indices are usually empirical

For full-maglev vertical superconducting gravity instruments, displacement control in the non-sensitive axis is a key technique to suppress cross-coupling noise in a dynamic environment. Motion decoupling of the test mass is crucial for the control design. In practice, when levitated, the test mass is always in tilt, and unknown parameters will be introduced to the scale factors of displacement detection

With the increasing demand for information security and security regulations all over the world, biometric recognition technology has been widely used in our everyday life. In this regard, multimodal biometrics technology has gained interest and became popular due to its ability to overcome a number of significant limitations of unimodal biometric systems. In this paper, a new multimodal biometric

Tools for remote radiation sensing are essential for environmental safety and nuclear power applications. The use of unmanned aerial systems (UASs) equipped with sensors allows for substantially reducing the radiation exposure of personnel. An ambient temperature Cs2LiYCl6:Ce3+ (CLYC) elpasolite scintillation sensor for simultaneous gamma and neutron measurements was designed as a user-friendly “plug

Background: For the nonstationarity of neural recordings in intracortical brain–machine interfaces, daily retraining in a supervised manner is always required to maintain the performance of the decoder. This problem can be improved by using a reinforcement learning (RL) based self-recalibrating decoder. However, quickly exploring new knowledge while maintaining a good performance remains a challenge

The modern-day vehicle is evolved in a cyber-physical system with internal networks (controller area network (CAN), Ethernet, etc.) connecting hundreds of micro-controllers. From the traditional core vehicle functions, such as vehicle controls, infotainment, and power-train management, to the latest developments, such as advanced driver assistance systems (ADAS) and automated driving features, each

We describe a concept study in which the changes of concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds and styrene within a 3D printer enclosure during printing with different acrylonitrile butadiene styrene (ABS) filaments were monitored in real-time using a proton transfer reaction mass spectrometer and an electronic nose. The quantitative data on the concentration of the

Environmental pollutants vigilance is one of the main problems that the aquaculture industry has to face with the objective to ensure the quality of their products and prevent entrance in the food chain that finally may arrive to the consumer. Contaminants such as hormones, antibiotics or biocides are especially relevant due to their toxicity, pharmacological effect or hormonal activity that can be

This paper describes an experimental study of the cooling capabilities of microchannel and micro-pin-fin based on-chip cooling systems. The on-chip cooling systems integrated with a micro heat sink, simulated power IC (integrated circuit) and temperature sensors are fabricated by micromachining and silicon-to-silicon direct bonding. Three micro heat sink structures: a microchannel heat sink (MCHS)

In this article, the application of the FRAME (Frequency Recognition Algorithm for Multiple Exposures) technique is presented for multi-species measurements in symmetric and asymmetric ethylene/air diffusion flames. Laminar Bunsen-type and swirled diffusion flames are investigated to gain a better understanding of sooting combustion. For this purpose, simultaneous imaging is conducted in terms of Laser-Induced

Knowledge of Global Navigation Satellite System (GNSS) antenna phase center variations plays a key role in precise positioning. Proper modeling is achieved by accessing antenna phase center corrections, which are determined in the calibration process. For most receiver antenna types, the International GNSS Service provides such corrections for two GPS and GLONASS carrier signals. In the case of Galileo

This paper presents the results of research on the airflow around a multirotor aircraft. The research consisted of the analysis of the velocity field using particle image velocimetry. Based on the tests carried out in a wind tunnel, the distribution of the velocity and its components in the vertical plane passing through the propeller axis were determined for several values of the angle of attack of

Detecting changes between the existing building basemaps and newly acquired high spatial resolution remotely sensed (HRS) images is a time-consuming task. This is mainly because of the data labeling and poor performance of hand-crafted features. In this paper, for efficient feature extraction, we propose a fully convolutional feature extractor that is reconstructed from the deep convolutional neural

Global Navigation Satellite System Reflectometry (GNSS-R) technology is a new and promising remote sensing technology, especially satellite-based GNSS-R remote sensing, which has broad application prospects. In this work, the ionospheric impacts on space-borne GNSS-R sea surface altimetry were investigated. An analysis of optimal values for spatial filtering to remove ionospheric delays in space-borne

Nowadays, the intelligent transportation concept has become one of the most important research fields. All of us depend on mobility, even when we talk about people, provide services, or move goods. Researchers have tried to create and test different transportation models that can optimize traffic flow through road networks and, implicitly, reduce travel times. To validate these new models, the necessity

Singular value decomposition (SVD) methods have aroused wide concern to extract the periodic impulses for bearing fault diagnosis. The state-of-the-art SVD methods mainly focus on the low rank property of the Hankel matrix for the fault feature, which cannot achieve satisfied performance when the background noise is strong. Different to the existing low rank-based approaches, we proposed a simultaneously

We analyze the source of the position deviation and propose a demodulation recursive compensation algorithm to ensure a sub-millimeter resolution in improved optical frequency domain reflectometry. The position deviation between the geometric path and optical path changes with the temperature or strain, due to the elastic-optic and thermal-optic effects. It accumulates along the fiber and becomes large

The affiliation of the first author was incorrectly published in the original article.

In this paper, we suggest to optimize power allocation coefficients and harvesting duration in mixed Radio Frequency (RF)/Free Space Optical (FS0) communications using Non Orthogonal Multiple Access (NOMA). The system model contains three time slots. In the first time slot, relay node R harvests energy from RF signal received from node H. Node H can be any node transmitting RF signals. In the second

Although "Heisenberg’s uncertainty principle’’ is represented by a rigorously proven relation about intrinsic uncertainties in quantum states, Heisenberg’s error–disturbance relation (EDR) has been commonly believed as another aspect of the principle. Based on the recent development of universally valid reformulations of Heisenberg’s EDR, we study the error and disturbance of Stern–Gerlach measurements

We propose a method to achieve photon pair propagation in an array of three-level superconducting circuits. Assuming experimentally accessible three-level artificial atoms with strong anharmonicity coupled via microwave transmission lines in both one and two dimensions we analyze the circuit Quantum Electrodynamics(QED) of the system. We explicitly show that for a suitable choice of the coupling ratio

Surface codes are a promising method of quantum error correction and the basis of many proposed quantum computation implementations. However, their efficient decoding is still not fully explored. Recently, approaches based on machine learning techniques have been proposed by as well as . In these approaches, a so called high level decoder is used to post-correct an underlying decoder by correcting

We investigate the feasibility of using an effective pulse control methods to realize an almost exact state transmission through a uniform chain where the communication channel is immersed in a quantum environment. This pulse control is treated in a non-perturbative fashion, allowing for a more precise view. Using the non-Markovian quantum state diffusion equation, we calculate the dynamics of the

Simultaneous dual-plane stereoscopic particle-imaging velocimetry (DS-PIV) and hydroxyl planar laser-induced fluorescence (OH-PLIF) was performed at 10 kHz repetition rate in a highly turbulent swirling jet flame. The burst-mode laser system provides sufficient 532-nm dual-pulse energy enabling high-speed large-area dual-plane stereo-PIV measurement. The scattered light from the two planes was separated

In this work, we introduce a four green-light wavelength splitter device, based on six slot-waveguide structures. Silica and gallium nitride materials were chosen for confining the green light inside the slot-waveguide area in a transverse magnetic field mode. The device functioned as a 1 × 4 demultiplexer, which demultiplexes wavelengths in the green-light band with wavelength range of 500–530 nm

In this paper, a new type of microwave microfluidic sensor is presented, using three separate half wave microstrip resonators with a common junction. The sensor comprises three parallel resonators with resonant frequencies of 2.5, 3.5, and 4.5 GHz. This sensor exhibits all the usual advantages of microwave resonant methods for dielectric liquid characterization, such as high precision, accuracy, and

A technique for the reduction of third‐order intermodulation distortion (IMD3) occurring in bulk acoustic wave (BAW) filters and multiplexers is presented. The method consists of using the intrinsic second‐order intermodulation distortion generated by BAW filters and multiplexers themselves by injecting an externally controlled amplitude and phase modulated signal at low frequency to compensate for

A novel dielectric waveguide filter based on isosceles right‐angled triangular (RAT) resonators is presented in this letter. By connecting the vertices of four isosceles RAT waveguide cavities, a square fourth‐order cross‐coupled waveguide bandpass filter is formed. The presented filter uses the partition wall and shallow blind hole to realize positive coupling and the deep blind hole to realize negative

It was shown, that Cu-doped hexagonal phases YGaO3, YInO3 and GdInO3 possess an intense broadband photoluminescence in the near infrared region. This photoluminescence is attributed to the unique crystalline lattice of studied hexagonal phases with trigonal-bipyramidal coordinated Ga3+ and In3+ ions. It was suggested that an emissive center in these phases is formed by heterovalent substitution of

The need for secret sharing using meaningful shadow images is an important method to protect the transmitted data that does not attract the attention of adversary, which has become obvious in the past few years. The recovery of the cover image without any distortion and security of the embedded secret string efficiently needs to be addressed. This paper proposes an invertible (k,n) secret sharing scheme

An efficient, accurate numerical method is developed to study the mixed (bright-bright-dark) solitons in a three component mixed coupled nonlinear Schrödinger system, arising in nonlinear optics. For this purpose, a compact finite difference method involving different boundary conditions for the bright and dark solitons is employed to derive an implicit nonlinear numerical scheme of fourth order in

In this work, perovskite La1−xNixMnO2.75 (with x = 0, 0.1, 0.2, 0.3 and 0.4) is synthesized by spray pyrolysis route at 460 °C. X-ray pattern analysis showed orthorhombic structure of the pure and Ni-doped. Based on X-ray analysis interesting parameters are then extracted such as crystallite size, micro-strain (ε) and dislocation density (δ). A high transmittance coefficient at 76 % and the optical

Raman spectroscopy is a non-destructive testing technology that has been widely used in biomedicine and other fields. However, the spontaneous Raman signal is weak. Therefore, the data collection is very time consuming, which has seriously hindered the application of Raman imaging technology in the fast dynamic system. At present, the reconstruction of Raman spectra based on multi-channel measurements

Synchronous measurement of full-field temperature and deformation at elevated temperature using non-contact optical methods attracts increasing attention in evaluating the high temperature properties of materials. The current optical methods all face one major challenge, which is the strong light reflection on the surface of the specimen. Such strong light reflection could greatly impair the measurement

Improving the time efficiency of fringe projection profilometry (FPP) is an attractive problem. For FPP using phase-shifting, it is desired to improve the efficiency by reducing the step number for phase retrieval. This paper proposes a two-step phase-shifting algorithm dedicated to FPP. Considering the physical process of FPP, the captured fringe image is formulated with two variables, i.e. surface

An optical color image encryption method based on Hadamard single-pixel imaging (SPI) and Arnold transformation is proposed, in which, optical full-color image encryption with good imaging quality and high security performance can be accomplished by only one bucket detector (BD). In the encryption process, after controlling and modulating the Hadamard matrix by the coefficient matrix key, three different

In medical imaging, segmenting brain tumor becomes a vital task, and it provides a way for early diagnosis and treatment. Manual segmentation of brain tumor in magnetic resonance (MR) images is a time‐consuming and challenging task. Hence, there is a need for a computer‐aided brain tumor segmentation approach. Using deep learning algorithms, a robust brain tumor segmentation approach is implemented

A calibration method of shear amount based on the optical layout of point source microscope (PSM) for lateral shearing interferometric (LSI) wavefront sensor is proposed. A simulation model of quadriwave LSI is introduced to analyze the influence of the window size of the spatial filter and the shear amount on the accuracy of the shearing wavefront feature extraction (SWFE) method. Simulation results

3D shape measurement systems based on diffuse reflection of projected structured light are widely used. Unfortunately, this measurement principle does not work for uncooperative materials, i.e., materials with optical properties such as being glossy, transparent, absorbent, or translucent. Recently, it was shown that 3D reconstruction of an uncooperative object can be performed by a two-step process

Significance: Cerebral blood flow is an important biomarker of brain health and function as it regulates the delivery of oxygen and substrates to tissue and the removal of metabolic waste products. Moreover, blood flow changes in specific areas of the brain are correlated with neuronal activity in those areas. Diffuse correlation spectroscopy (DCS) is a promising noninvasive optical technique for monitoring

Significance: The retina is critical for vision, and several diseases may alter its biomechanical properties. However, assessing the biomechanical properties of the retina nondestructively is a challenge due to its fragile nature and location within the eye globe. Advancements in Brillouin spectroscopy have provided the means for nondestructive investigations of retina biomechanical properties. Aim:

Significance: Previous studies have been performed to image photosensitizers in certain organs and tumors using fluorescence laminar optical tomography. Currently, no work has yet been published to quantitatively compare the signal compensation of fluorescence laminar optical tomography with two-dimensional (2-D) imaging in tissues. Aim: The purpose of this study is to quantify the benefit that fluorescence

Significance: A significant amount of radical related luminescence is observed from the titanium dioxide (TiO2) plate during irradiation of alpha particles although alpha particles do not emit Cerenkov-light. Aim: TiO2 is a promising material for application to photodynamic therapy in combination with positron radionuclides that emit Cerenkov light. However, it is not clear that radicals are produced

Image enhancement, which aims at improving the contrast of low-light-level image and shows the details in the dark, is a widely used technology. When traditional multi-scale retinex (MSR) is used for low-light-level image enhancement, enhancement result will be over-enhanced and the so-called halo will occur. In order to overcome this shortcoming, the result of MSR needs to be further processed. First