Good Symmetry Research Articles

Impact of the Indian Ocean Dipole Mode on Planetary Boundary Layer Ozone in China

AbstractThe Indian Ocean Dipole (IOD) mode exerts distinct impacts on the climate in China and can further affect tropospheric ozone. Using long‐term GEOS‐Chem simulations, we found distinct changes in planetary boundary layer ozone throughout China during positive and negative phases of IOD. In summer, ozone shows synchronized increases except in southern China during positive IOD; the ozone increases are dominated by chemical production and transport in northern and western China, respectively. The increased precursor from biogenic emissions contributed to ozone chemical formation in the northern region, and the increased precipitation and decreased solar radiation hindered ozone production in southern China. Ozone changes show good symmetry over most regions during negative IOD. In autumn, the ozone reduction in southern China shares the same reason as summer, while the chemical increase over northern China is affected more by changes in solar radiation and relative humidity than in the precursor emission.

Implantable small ultra-wideband circularly polarized antenna design for continuous blood pressure monitoring

This paper presents a miniaturized circularly polarized (CP) implantable antenna Ultra-wide bandwidth for continuous blood pressure monitoring. The miniature and CP of the antenna are gained by using a new slot method. The symmetry slots in the radiation patch, two T-shape slots in the GND, coupled with the use of a short pin make the designed antenna with good physical and radiation properties. In simulation, the fractional effective axial ratio bandwidth is 23.6% (2.36–2.94 GHz), and the peak gain is − 28.9 dBi. Its total size is only 17.78 mm3 (0.056 × 0.04 × 0.004 λ03), which size is smaller compared to other antennas with similar performance. A prototype is fabricated and measured. The experimental results are in good agreement with the simulation results. And, the radiation patterns have good symmetry both in the simulation and measurement. In addition, the maximum SAR value is in accordance with the IEEE standard safety guidelines (IEEE C95.1-2019).

An Improved PINN Algorithm for Shallow Water Equations Driven by Deep Learning

Solving shallow water equations is crucial in science and engineering for understanding and predicting natural phenomena. To address the limitations of Physics-Informed Neural Network (PINN) in solving shallow water equations, we propose an improved PINN algorithm integrated with a deep learning framework. This algorithm introduces a regularization term as a penalty in the loss function, based on the PINN and Long Short-Term Memory (LSTM) models, and incorporates an attention mechanism to solve the original equation across the entire domain. Simulation experiments were conducted on one-dimensional and two-dimensional shallow water equations. The results indicate that, compared to the classical PINN algorithm, the improved algorithm shows significant advantages in handling discontinuities, such as sparse waves, in one-dimensional problems. It accurately captures sparse waves and avoids smoothing effects. In two-dimensional problems, the improved algorithm demonstrates good symmetry and effectively reduces non-physical oscillations. It also shows significant advantages in capturing details and handling complex phenomena, offering higher reliability and accuracy. The improved PINNs algorithm, which combines neural networks with physical mechanisms, can provide robust solutions and effectively avoid some of the shortcomings of classical PINNs methods. It also possesses high resolution and strong generalization capabilities, enabling accurate predictions at any given moment.

AcpAS: An Advanced Circularly Polarized Antenna Structure for an Airborne Relay Communication System

The airborne relay system is an important support for improving the stability of communication systems in complex electromagnetic environments. As a key component of the airborne relay system, the antenna needs to have characteristics such as high gain, dual circular polarization, wide beam coverage, and miniaturization. Based on the septum circular polarizer, this paper proposes a high-performance circularly polarized antenna structure suitable for airborne relay systems, named AcpAS. The structure consists of a coaxial feed port, a coaxial-to-waveguide transition, a septum circular polarizer, and a parabolic metal housing. Based on this structure, two antennas operating at 19.6 GHz to 21.6 GHz and 29.2 GHz to 31.2 GHz are designed in this paper. Simulated and measured results show that the two antennas have dual circular polarization characteristics, with beam coverage range of more than ±55° for gains higher than 0 dBi, and the radiation patterns exhibit good symmetry and wide-beam coverage characteristics.

Experimental study on seismic performance of assembled buckling-restrained brace with low yield point steel

Based on the design concept of seismic resilience, which aims to achieve controllable damage during earthquakes and rapid post-earthquake functional recovery within the structure, an assembled buckling-restrained brace with low yield point steel (ALYBRB) was proposed. To evaluate its seismic performance, quasi-static cyclic loading tests were conducted on five ALYBRB specimens. The influence of core steel material, bolt spacing of the external restraint system, and the gap between the core and the external restraint system on the seismic performance of ALYBRBs were investigated. The results indicated that the ALYBRBs exhibited superior plastic deformation capacity, stable energy dissipation capacity, and exceptional fatigue performance, as well as significant cyclic hardening characteristics and hysteretic properties with good symmetry. The cumulative plastic deformation coefficient (CPD) of ALYBRBs with LYP100 and LYP160 steel were 2.33 times and 1.51 times greater than that with Q235 steel, respectively. The maximum equivalent viscous damping coefficients of all specimens can achieve a range of 73.0 % to 86.2 % of the theoretically maximum value. The strain hardening adjustment factors of all specimens ranged between 1.34 and 1.90. The average compression strength adjustment factor for the properly designed ALYBRB specimens was 1.12. Reducing the bolt spacing can effectively inhibit the multi-wave buckling of the core, which is conducive to the improvement of energy dissipation efficiency in ALYBRBs. ALYBRB specimen with excessive gap exhibited decreased ductility, energy dissipation efficiency, and fatigue performance, and its out-of-plane deformation mode was a combination of bending deformation in the constrained yield segment and the transition segment deformation.

Neuron circuit made of a single locally-active memristor

Neuromorphic computing, inspired by the human brain’s architecture, is expected to break the physical limits of transistors and von Neumann bottleneck. The multiple internal state variables of higher-order memristors (second-order or above) possess dynamic complexity and adaptability, enabling them to mimick the characteristics of biological neurons, which are very important building blocks for neuromorphic computing. This paper presents a simple neuron circuit containing a single second-order current-controlled locally-active memristor (LAM). The pinched hysteresis loop and DC V–I curve of the proposed second-order LAM show good odd symmetry. Applying small signal analysis method, we obtain the small-signal equivalent circuit of the neuron circuit, showing a [Formula: see text] parallel structure and an edge of chaos kernel in its locally-active domain. Also, we draw a parameter classification of the neuron circuit, showing four symmetrical edge of chaos domains, which plays an important role in biphasic action potentials. Finally, we demonstrate that the simple neuron circuit can produce monophasic action potentials, biphasic action potentials and co-existing neuromorphic phenomena via subcritical Hopf bifurcation with different input, verifying the simple circuit is suitable as artificial neurons.

Analysis of maxillary teeth and soft tissue profiles among Tibetan and Han Chinese females with facial symmetry for orthodontic treatment planning.

The evaluation of maxillary teeth and soft tissue profiles is a critical component of orthodontic diagnosis and treatment planning. This study aimed to evaluate the correlation between the sagittal position of maxillary anterior teeth and facial profile esthetics among Tibetan and Han Chinese adult females for optimizing orthodontic diagnosis and treatment planning. A total of 100 Tibetan Chinese and 100 Han Chinese adult females with good facial symmetry were recruited. The smiling facial profile images with the maxillary central incisors and forehead in full view were taken based totally on the same standard. The photo measurement and head position were adjusted using the picture-enhancing software. The reference traces associated with forehead inclinations were utilized to assess the anteroposterior (AP) positions of the maxillary central incisors. The results showed that a round forehead was the dominant forehead shape for Tibetan (93%) and Han (55%) Chinese females. In Tibetan females, 85% of the maxillary central incisors were found to be located between the forehead's anterior limit line (the Gall line) and the goal anterior limit line (the Fall line), with 15% located posterior to the Fall line. This distribution manifested a strong association with incisor position and forehead inclination (R2 = 0.742). In Han females, 83% of the maxillary central incisors were located between the Fall line and the Gall line, with 12% posterior to the Fall line and 5% anterior to the Gall line. The positions of the maxillary central incisors exhibited a strong relationship with forehead inclination (R2 = 0.827). The maxillary central incisors were close to the aesthetic line in both ethnic groups, while forehead inclinations were correlated with AP maxillary incisor position. These findings demonstrated that there was a close relationship between the incisor position of Tibetan and Han females with facial symmetry and the forehead FFA factor, indicating a reference in oral hard and soft tissues for optimizing orthodontic diagnosis and treatment planning in terms of facial contour.

A structure-preserving algorithm for Vlasov–Darwin system conserving charge, canonical momentum, and Hamiltonian

In this paper, a conservative numerical method for the Vlasov–Darwin system is proposed. The Darwin model was assumed to be valid only in the Coulomb gauge, but recently this model has also been extended to the Lorenz gauge [1]. The Darwin model, based on the Lorenz gauge, exhibits a good symmetry between scalar and vector potentials, making the proofs of physical constraints relatively easy. In addition, the total energy was believed to be one of the conservative quantities of the Vlasov–Darwin system. However, the improved theory suggests that the Hamiltonian is the conservative quantity rather than the total energy. The structure-preserving scheme proposed in this paper exactly maintains the Lorenz gauge and the conservation laws of charge, canonical momentum, and Hamiltonian in discrete form.

Gravitational effects on large-scale premixed flame dynamics: From linear to nonlinear evolution

Gravitational effects on premixed flame propagation, coupled with Darrieus–Landau instability, are investigated through direct numerical simulations under both thermal-diffusive (TD) stable and unstable situations. During the early stage of propagation, the dispersion relation between the linear growth rate σ and wavenumber k of perturbations exhibits good symmetry, allowing it to be well-fitted by the polynomial σ=c+ak−bk2. The modified Clavin–Garcia relation derived from asymptotic analysis aligns with numerical results only in the low-wavenumber region, since the significant error in the second-order coefficient bg renders it inapplicable for the high-wavenumber region. In the nonlinear regime, three morphological effects of gravity on the flame propagation have been identified: flattening the flame front, suppressing the cusp fusion rate, and promoting the new cusp generation (front splitting). The first two effects slow down the flame propagation, respectively, by reducing the overall flame front length and delaying the appearance of velocity peaks. Nevertheless, the promotion of front splitting accelerates the flame by facilitating more frequent velocity peaks arising from both cusp generation and fusion events. These various morphological effects, along with their distinct impacts on either accelerating or decelerating the flame propagation, result in significant variations in the behavior of large-scale flame propagation under different gravitational levels, despite gravity being a large-scale stabilizing effect.

The edge fault-tolerance about the strong Menger edge-connectivity of order [formula omitted] among hamming graph

Let r≥0 be a fixed integer. If F is an edge set of a connected graph G satisfying the minimum degree of G−F being at least r, then F is a conditional faulty edge set of order r. The graph G is called F-strongly Menger-edge-connected if each pair of vertices u and v are connected by min{degG−F(u),degG−F(v)} edge-disjoint paths in G−F, where degG−F(u) and degG−F(v) are the degrees of u and v in G−F, respectively. A graph G is m-strongly Menger-edge-connected of order r if G is F-strongly Menger-edge-connected of order r for every F⊂E(G) with |F|≤m and F is a conditional edge fault set of order r, and the maximum value of m is written as smλr(G). Hamming graph KLn has been widely concerned by researchers due to its excellent properties such as good connectivity, scalability, symmetry and iterativity. This paper considers various sufficient conditions of KLn to be F-strongly Menger-edge-connected of order r and determine the exact value of smλ(L−1)r(KLn) by studying the edge-disjoint paths in KLn with edge faults, smλ(L−1)r(KLn)=(L−1)Lr(n−r)−(L−1)n, where 0≤r≤n−2 and n≥3.

The Scar-Hidden Surgery on Gynecomastia: Experiences from a Single-Institutional Large Case Series.

To summarize the experiences on the mastoscopic subcutaneous mastectomy for gynecomastia by "nine-step method" based on the "5S" goal and standardize this operation. Between January 1, 2002, and October 31, 2021, a total of 2035 breasts of 1082 male patients with gynecomastia, of which 129 patients with one side, were underwent mastoscopic subcutaneous mastectomy. The follow-up endpoint was 3months after surgery. All patients were successfully completed the operation, and none of them was transferred to open operation. The operation time for unilateral breast was 12-28min, and the average time was 17.7 ± 6.2min. The amount of bleeding during unilateral operation was very small, about 5-10ml. The total drainage volume was 5-50ml after the operation, and the drainage tube was removed in 3-5days. The epidermal necrosis occurred in 0.3% nipple. 0.2% chest wall had a little ecchymosis in the supero-medial region of the breast. All patients had the normal feeling of nipples and areola, the smoothing and symmetrical chest wall, and the natural contour. There was no recurrence during the follow-up period. The mastoscopic subcutaneous mastectomy for gynecomastia by "nine-step method" based on the "5S" goal has a short operation time, few surgical complications and good esthetics. It achieves the "5S" goals on the complete removal of glandular tissue (sweeping), small and scar-hidden incision are small (scarless), good symmetry of bilateral chest wall (symmetry), normal chest shape (shape), and smoothing chest wall (smoothing). The journal asks authors to assign a level of evidence to each article. For a complete description of Evidence-Based Medicine ratings, see the Table of Contents or the online Instructions for Authors at www.springer.com/00266 .

Mandibular Fracture in a Newborn From Birth Trauma: A Case Report

Objective: To report a case of mandibular fracture in a newborn presenting with post-delivery oral cavity bleeding and to discuss its etiology, clinical findings, diagnosis, management and outcome after treatment. Methods: Design: Case Report Setting: Tertiary Government Training Hospital Patient: One Results: A newborn girl was referred for oral cavity bleeding after partial breech extraction. An intraoral hematoma and symphyseal step deformity on examination corresponded to a complete fracture of the symphysis and downward displacement of the left hemimandible on facial CT scans with 3D reconstruction. An uneventful closed reduction with external fixation using acrylic cap splint with circum-mandibular wiring was performed under general anesthesia and she was discharged feeding well. The cap splint and wires were removed after 4 weeks showing good facial symmetry and bone alignment. There were no complications on follow-up after 1 year. Conclusion: Mandibular fracture can result from traumatic delivery and present with oral bleeding and hematoma. A thorough physical examination and workup should be done to assess for the sites involved. A multidisciplinary approach should be undertaken to provide the best possible care with the least invasive technique.

Fully optically controlled Li-ion-mediated artificial vision reflection arc system

Artificial vision systems have been extensively reported for processing unstructured data, performing pattern recognition, and performing visual simulations. Photonic synapses have become the core of most artificial vision systems due to their advantages such as low energy consumption and ultra-fast signal transmission. However, their integration is difficult, the integration difficulty of photon synapses is higher than that of crossbar arrays. Moreover, due to the hybrid drive of light and external power supply, low energy consumption and weight update under full optical control cannot be achieved. Here, we designed a fully light-controlled multifunctional artificial vision reflex arc system. The solar cell and oscillator generate presynaptic voltage signals that are then transmitted to a lithium-ion-based memristor for the stimulation of different wavelengths and light intensities. The results show that our artificial vision system can distinguish wavelength and light intensity information and has good weight update symmetry and repeatability. Finally, the deformation experiment of the shape memory alloy demonstrated that the system can be used for controlling artificial muscles under different light signals.

Optimization of cobalt-based MOFs for super-capacitor electrode materials of new energy vehicle

Super-capacitors (SCs), as new energy conversion storage elements, have attracted much attention, but there is still a research gap in the design of electrode materials. In this study, the optimization scheme of Metal-Organic Frameworks (MOFs) and cobalt-based MOF composites as electrode materials for SCs in new energy vehicles is explored, and a series of experiments are conducted to evaluate their performance. Scanning Electron Microscope (SEM) images reveal that the cobalt-based MOF composites have a surface morphology of particles with uniform distribution. The electrochemical performance test results show that the specific capacitance of the cobalt-based MOF composites is much higher than the sum of the two individual electrode materials and presents a remarkable increase with the scanning rate. Additionally, in the constant current charge-discharge test, cobalt-based MOF composites exhibit the longest charge-discharge time and good symmetry. Electrolyte particle contact tests for samples at different preparation temperatures display that high-temperature samples have better structural stability and electrolyte ion contact. In Cyclic Voltammetry (CV) and Galvanostatic Charge Discharge (GCD) tests, the 250 °C sample demonstrates the best electrochemical properties and the highest specific capacitance (269 F/g). Moreover, as the current density increases, the specific capacitance of the 600 °C sample decreases at a lower rate, showing stronger stability. However, the use of cobalt-based MOF materials may pose environmental and safety risks, such as the environmental impact of cobalt resource mining, instability under high-temperature conditions, and the possible production of hazardous substances. Therefore, these factors need to be fully considered when designing and using SCs to ensure the environmental friendliness and safety of cobalt-based MOFs. These results provide an important reference for selecting and optimizing electrode materials for SCs in new energy vehicles. Furthermore, this study offers research suggestions for improving new energy materials, filling the research gaps in related fields, and supporting the further development of SC technology.

Pseudospin symmetry in resonant states in deformed nucleus 154Dy

It is known that pseudospin symmetry plays a crucial role in formation of many physical phenomena. By combining the relativistic mean field theory with the complex momentum representation method, the pseudospin symmetry in the single particle resonant states in the deformed nucleus [Formula: see text]Dy is investigated through the energy and width splittings, the quadrupole deformation parameter, the radial density distributions and occupation probabilities of the pseudospin doublets. Near the continuum threshold, the pseudospin symmetry is well reserved in both bound and resonant states. The energy and width splittings of pseudospin doublets in resonant states exhibit correlations with the deformation and quantum numbers. The good pseudospin symmetry is expected with lower pseudo-orbital angular momentum projection [Formula: see text] and the main quantum number N. In general, an increase in deformation tends to weaken the quality of the pseudospin symmetry. The understanding of the evolution of the pseudospin doublets in the resonant states has been deepened by studying the pseudospin symmetry in the deformed nuclei.

A 2 µm Gallium Antimonide Semiconductor Laser Based on Slanted, Wedge-Shaped Microlens Fiber Coupling

Semiconductor lasers with a wavelength of 2 µm, composed of antimonide materials, find important applications in trace gas detection, laser medicine, and free-space optical communication, among others. In this paper, a more suitable microlens shape for 2 µm gallium antimonide semiconductor lasers is designed. Based on the fiber coupling efficiency model, the parameters of the designed slanting wedge-shaped microlens fiber are optimized to improve laser beam quality. The large tangent angle on both sides of the slanted, wedge-shaped microlens fiber is calculated using Snell’s law, and the fiber core diameter and small wedge angle are determined through space fiber coupling experiments. After packaging the fiber coupling module with the chip, the laser output beam exhibits good overall symmetry in the spot with a uniform intensity distribution. The maximum output power is approximately 210 mW, demonstrating good power stability.

Soft Dipole Resonances in 8He and 8C

Soft dipole resonances in 8He and 8C are investigated by applying the complex scaling method to the α + N + N + N + N five-body model for the isospin T = 2 system. The 1− excited resonant states are calculated at (Ex, Γ) = (14.0, 21.1) MeV and (12.7, 24.0) MeV for 8He and 8C, respectively. From the analyses of the configuration mixing and the spatial properties, the soft dipole resonances of two nuclei are understood to be the vibrational states of valence nucleons and the α core. They are also seen to have a good isospin symmetry. In contrast, the ground states of two nuclei show different spatial properties indicating the symmetry breaking due to the Coulomb repulsion of valence protons in 86C2.

A successful surgical management of pediatric ossifying fibroma in peripheral limited setting: a rare case report

Ossifying fibroma (OF) is a rare non-malignant fibro-osseous lesion of the craniofacial area with the characteristic of slow-growing and locally aggressive. The incidence rate in paediatric patients is still not clear. The management is varied from observation and serial radiologic imaging to radical resection of the tumour. To provide knowledge and information about diagnosing and managing a rare case of craniofacial ossifying fibroma. A-5-year-old boy diagnosed with orbito-inferonasal region ossifying fibroma underwent extirpation of the mass with the lateral rhinotomy- Webber Ferguson approach, anterior orbitotomy by the ophthalmologist, and obturator placement by the prosthodontist. OF remains a rare disease, particularly in paediatric patients, which is locally aggressive although it’s benign characteristic. Definitive excision is the treatment of choice for OF. Successful surgical outcome was due to a multidisciplinary team and surgical incision technique. We found that lateral rhinotomy Weber Ferguson incision showed excellent exposure. Vision and facial nerve function were preserved as well as good facial symmetry and aesthetics and recurrence prevention. Regular follow-up is necessary for young OF patients.

Fast Stray Light Performance Evaluation Based on BSDF and Radiative Transfer Theory.

Evaluating the stray light cancellation performance of an optical system is an essential step in the search for superior optical systems. However, the existing evaluation methods, such as the Monte Carlo method and the ray tracing method, suffer from the problems of vast arithmetic and cumbersome processes. In this paper, a method for a rapid stray light performance evaluation model and quantitatively determining high-magnitude stray light outside the field of view are proposed by adopting the radiative transfer theory based on the scattering property of the bidirectional scattering distribution function (BSDF). Under the global coordinates, based on the derivation of the light vector variation relationship in the near-linear system, the specific structural properties of the off-axis reflective optical system, and the specular scattering properties, a fast quantitative evaluation model of the optical system's stray light elimination capability is constructed. A loop nesting procedure was designed based on this model, and its validity was verified by an off-axis reflective optical system. It successfully fitted the point source transmittance (PST) curve in the range of specular radiation reception angles and quantitatively predicted the prominence due to incident stray light outside the field of view. This method does not require multiple software to work in concert and requires only 10-5 orders of magnitude of computing time, which is suitable for the rapid stray light assessment and structural screening of off-axis reflective optical systems with a good symmetry. The method is promising for improving imaging radiation accuracy and developing lightweight space cameras with low stray light effects.

A Triple-Band Broadband Miniature Antenna Design for Implantable Continuous Glucose Monitoring

This paper presents a miniaturized triband implantable planar antenna that covers the industrial, scientific, and medical (ISM) band and the Wireless Medical Telemetry Service (WMTS) band which can be used in a continuous blood glucose monitoring device. The antenna consists of a slotted radiating patch and a ground plane with a cross slot to miniaturize its size. The overall antenna size is only 51.35 mm3 (7.6 × 7.6 × 0.889 mm3) due to the reduced size by the slotting technique. Compared to other implantable antennas with similar performance, the proposed antenna is smaller in size, simple in construction, and easy to be fabricated. By cutting a cross slot in GND, impedance matching is improved, especially at the two higher frequency bands. We have fabricated the prototype and carried out measurements. The results show its gains are −32.2 dBi, −18.8 dBi, and −19.1 dBi at 0.9 GHz, 1.4 GHz, and 2.45 GHz, respectively. Its radiation patterns have good symmetry in the two lower operating frequency bands. In addition, the maximum SAR values comply with the IEEE standard safety guidelines (IEEE C95.1-2019).