Search Results (76)

Industrial Internet of Things (IIoT) networks require continuous, uninterrupted sensing operations despite the finite battery capacity of deployed IoT nodes. Conventional reactive energy management, where nodes switch to charging mode only after residual energy falls below a fixed threshold, cannot prevent depletion events and compromises network uptime. We propose a digital twin (DT)-enabled predictive scheduling framework in which a DT layer co-located with a multi-access edge computing (MEC) control center continuously mirrors the physical network state and generates H-slot look-ahead scheduling decisions before depletion can occur. The framework operates over a 5G network-sliced infrastructure with dedicated URLLC, eMBB, and mMTC slices. Two coupled integer programming problems are formulated, namely a predictive IoT node scheduling problem and a predictive energy transmitter scheduling problem. Optimal solutions are obtained via branch-and-bound with reliability branching (DT-PBB), and a low-complexity DT-Aware Greedy Priority Heuristic (DT-GPH) is also proposed. Evaluated against Earliest-Deadline-First (EDF-WPT), No-WPT (a baseline that disables wireless charging entirely), and Random baselines across three parameter configurations with K up to 200 nodes, DT-PBB achieves the highest sensing utility and the fewest energy depletion events in all scenarios. DT-GPH provides near-optimal depletion performance at substantially lower computation cost. EDF-WPT, the strongest reactive policy, incurs 2-4 times more depletion events than DT-PBB. Proactive DT-enabled look-ahead decisively outperforms reactive urgency-based scheduling, validating the zero-downtime paradigm for large-scale IIoT networks. Full article

We review recent interferometric schemes designed to probe physics beyond the Standard Model through the detection of geometric phases. Within the kinematic approach to non-cyclic geometric phases, we discuss how interactions with hidden-sector degrees of freedom, such as axion-like particles and mirror-matter candidates, can induce potentially observable phase shifts in ordinary fermionic systems. We further show how the same geometric framework can be extended to particle mixing systems and fundamental symmetries, providing a phase-based signature of the Charge–Parity–Time (CPT) violation. These results illustrate how geometric phases can encode information that is not always directly accessible through standard transition probabilities, making quantum interferometry a complementary tool for testing dark-sector interactions, fundamental properties of elementary particles, acceleration-induced quantum-field effects, and phase-based thermometry. We also critically assess the experimental requirements and limitations of the proposed schemes. Full article

Single-molecular white circularly polarized luminescence emitters show promise for use in chiral displays and solid-state lighting, but their design remains challenging because broadband emission, exciton utilization, color balance, and chiroptical activity must be integrated within one molecule. Herein, we report a chiral single-molecular white emitter, DCz-PTZ, constructed through a π-interrupted strategy by combining a rigid spiro framework, an oxygen-bridged carbazole/cyanobenzene segment, and a phenothiazine donor. The interrupted conjugation suppresses excessive charge-transfer (CT) domination and enables dual emissive channels, including short-wavelength locally excited (LE) emission and long-wavelength CT emission. DCz-PTZ exhibits near-ideal white emission in dilute toluene solution with CIE coordinates of (0.33, 0.33), and maintains balanced dual emission in 5 wt% doped films with CIE coordinates of (0.32, 0.34). Photophysical studies support the assignment of the yellow emission to a thermally activated delayed fluorescence (TADF)-active CT state. The enantiomers show mirror-image circularly polarized signals with |g_lum| up to 2.9 × 10⁻³. Optimized white organic light-emitting diodes (WOLEDs) achieve color rendering index (CRI) up to 92 and a maximum external quantum efficiency (EQE_max) of 1.3%. This work demonstrates a π-interrupted molecular strategy for integrating dual emission, TADF exciton utilization, and circularly polarized electroluminescence (CPEL) in a single chiral emitter. Full article

Optimized dispatch of microgrids is crucial for improving the economic performance and long-term sustainability of modern low-carbon power systems. In particular, accurate economic dispatch modeling for battery energy storage systems (BESSs) is essential for properly evaluating the operational benefits and lifetime costs of microgrids. However, when both battery cycle aging and calendar aging are considered, the resulting scheduling model becomes highly nonlinear, high-dimensional, non-convex, and multimodal, which poses substantial challenges to conventional optimization methods. To alleviate the above problem, a symmetry-guided multi-strategy differential hybrid slime mold algorithm (MDHSMA) is introduced for the day-ahead economic dispatch of microgrids under a refined battery degradation framework. First, a chaotic bimodal mirrored Latin hypercube sampling strategy is designed to exploit symmetry during population initialization, thereby enhancing diversity and improving structured coverage of the search space. Second, a history-driven adaptive differential evolution mechanism is integrated to balance global exploration and local exploitation more effectively during the iterative search process. Third, a state-aware stagnation handling framework is incorporated to maintain population vitality and further improve convergence accuracy and robustness. MDHSMA is evaluated against 12 state-of-the-art optimizers on the CEC2017 and CEC2022 benchmark suites and two representative engineering optimization problems to verify its overall performance. In addition, it is applied to a microgrid case study with refined BESS degradation modeling. The results show that MDHSMA achieves the lowest comprehensive operating cost by effectively coordinating electricity arbitrage and battery life consumption. Moreover, it guides the energy storage system toward shallow charge–-discharge patterns, thereby mitigating accelerated degradation caused by excessive cycling. These results confirm the effectiveness and practical value of the proposed method for sustainable microgrid dispatch in complex nonconvex optimization scenarios. Full article

The echelle spectrometer utilizes an echelle grating as the primary dispersive element, combined with a prism or planar grating for cross-dispersion, to form a two-dimensional spectral image on an area-array Charge-Coupled Device (CCD). Compared with traditional spectrometers, this configuration provides superior spectral resolution, broader wavelength coverage, enhanced transient direct-reading capability, and higher energy throughput within a similar footprint. However, the use of area-array detectors significantly increases system cost, limiting adoption in cost-sensitive applications. To reduce cost while maintaining performance, we introduce a digital micromirror device (DMD) as a spatial light modulator to replace the traditional area-array detector, paired with a highly sensitive photomultiplier tube (PMT) for signal acquisition. The designed system operates across a wavelength range of 270 to 800 nm within a compact footprint of approximately 307 mm × 210 mm × 150 mm. The focused spot is accurately positioned on the DMD surface across the entire band, with the root mean square (RMS) spot radius smaller than a single micromirror’s size. Spectral information is efficiently coupled into the PMT via a focusing mirror by selectively flipping the DMD micromirrors for detection. Full article

We theoretically investigate multiple-Q instabilities in centrosymmetric hexagonal magnets, formulated as superpositions of independent six ordering wave vectors related by sixfold rotational and mirror symmetries. By employing a spin model that incorporates biquadratic interactions and an external magnetic field, we establish a comprehensive low-temperature phase diagram hosting single-Q, double-Q, triple-Q, and sextuple-Q states, as well as skyrmion crystals with topological charges of one and two. The field evolution of the magnetization, scalar spin chirality, and finite wave-vector magnetic amplitudes reveals a hierarchical buildup of multiple-Q order, accompanied by first-order transitions between topologically distinct and trivial phases. At large biquadratic coupling, all six symmetry-related ordering wave vectors coherently participate, giving rise to two sextuple-Q states under magnetic fields and to another spontaneous sextuple-Q state even at zero field. The latter zero-field sextuple-Q state represents a fully developed sixfold interference pattern stabilized solely by the biquadratic interaction, characterized by alternating skyrmion- and antiskyrmion-like cores with vanishing uniform scalar spin chirality. These findings establish a unified framework for understanding hierarchical multiple-Q ordering and demonstrate that the interplay between bilinear and biquadratic interactions under hexagonal symmetry provides a generic route to complex noncoplanar magnetism in centrosymmetric itinerant systems. Full article

This paper presents a self-contained startup charging circuit designed for energy-harvesting batteryless IoT devices. The proposed circuit consists of a current-biasing block, a current mirror, a reference voltage generator, and a comparator circuit. The current-biasing circuit drives the current mirror, which supplies the charging current to the energy storage element. Simultaneously, the reference voltage generator—also biased by the current source—produces a stable DC reference voltage. When the energy storage device (e.g., a supercapacitor) lacks sufficient charge, the comparator enables the charging path by activating the current-biasing and mirror circuits. Once adequate energy is stored, the comparator disables these circuits to prevent overcharging. This self-contained solution is intended to autonomously initialize and manage the cold-start charging process in energy-harvesting systems without relying on external controllers. This paper highlights the circuit architecture and validated performance, demonstrating a charging current of up to 27 mA, a reference voltage of 700 mV, and an operating range from 0.9 V to 1.8 V across a temperature range of −40 °C to 85 °C. Full article

We report that poly(vinyl alcohol) (PVA) matrices facilitate nanosecond photoinduced electron transfer (PET) from cyanine dyes to CaTiO₃ nanocrystals, yielding distinct radical cation excited-state absorption (ESA) with well-resolved D₀→D₁ and D₁→D₂ transitions. In dye-only PVA films, UV hole-burning produces a minority radical cation population, evidenced by a blue-shifted ESA band mirroring the D₁→D₂ manifold. Kinetic analysis of the ternary PVA–dye–CaTiO₃ system reveals a shared nanosecond decay (τ₂ ≈ 4–7 ns) for both oxide ESA and radical cation transitions, confirming coupled charge-separated states. These results establish orbital-level insight into how polymer matrices regulate PET and radical stabilization, providing a mechanistic foundation for programmable hybrid photonic devices. Full article

Surface charge accumulation is an important cause of flashover accidents for DC pillar insulators and the failure of DC gas insulation equipment. In this paper, the DC pillar insulator is taken as the research object, and a surface potential measurement system is built. The surface potential distribution of the pillar insulator under different voltages is measured. An inversion algorithm based on the B-spline basis function is proposed. The electric field simulation model of the DC pillar insulator considering the gas’s weak ionization and surface conductance is established. The surface charge accumulation characteristics of the pillar insulator under different DC voltages are studied. The results show that the surface potential of the DC pillar insulator presents an oscillating distribution in the axial direction, and the potential distribution is approximately mirror symmetry under positive and negative voltages. The surface charge density is non-uniform in the axial direction, and the surface charge distribution is different under different voltages. In addition, the current density on the solid side gradually approaches and exceeds the current density on the gas side with the increase in the applied voltage, which promotes the accumulation of charges on the insulator surface with the same symbol as the electrode to weaken the field strength and balance the normal electric field components on both sides. Full article

This study aims to evaluate the effects of total ionizing dose (TID) radiation on the performance of n−MOSFET current mirrors. We propose an ovel experimental approach to analyze the interaction between charge trapping in the MOSFET gate oxide and the resulting current mirror degradation by subjecting devices to TID doses from 50 krad(Si) to 300 krad(Si) using a 60Co gamma source Experimental data show that threshold voltage shifts by up to 1.31 V and transconductance increases by 27%. This degradation leads to this a reduction of more than 10% in current mirror output accuracy occurs at the highest dose. These quantitative criteria establish a clear benchmark for assessing the impact of TID on current mirror performance. These effects are attributed to positive charge trapping in the gate oxide and at the Si–SiO₂ interface induced by ionizing radiation. This study focuses exclusively on radiation effects; electrical stress phenomena such as over−voltage or electrostatic discharge (ESD) are not addressed. The results highlight the critical importance of accounting for TID effects when designing high−performance n−MOSFET current mirrors for radiation−hardened applications. Full article

Currently, as research on hydrogel beads intensifies, the application scope of chitosan-based hydrogel beads is increasingly expanding. Owing to their unique three-dimensional network structure, chitosan-based hydrogel beads are frequently utilized for encapsulating bioactive substances and adsorbing impurities. The primary material used in the preparation of chitosan-based hydrogel beads is chitosan, which is uniquely a natural polysaccharide possessing a positive charge. Derived from a diverse array of sources, chitosan is non-toxic, exhibits excellent biocompatibility, and possesses certain antibacterial properties. Because of these remarkable attributes, it has found widespread application in tissue engineering, the formulation of drug carriers, and the adsorption of heavy metals and dyes in wastewater. The preparation method for chitosan-based hydrogel beads largely mirrors that of other hydrogel beads. According to existing research, numerous methods exist for crafting hydrogel beads with diverse properties. This paper reviews the preparation methods of chitosan-based hydrogel beads, encompassing both physical and chemical crosslinking techniques. The physical crosslinking method leverages electrostatic interactions between materials to form hydrogel beads, whereas the chemical crosslinking method involves the use of chemical crosslinking agents to facilitate the formation of hydrogel beads through material-based chemical reactions. Given that chitosan carries a positive charge and other polysaccharide materials possess a negative charge, the combination of these materials can yield hydrogel beads with a dense structure, effectively encapsulating bioactive substances. This dense internal structure offers superior protection for the encapsulated bioactive substances. Chitosan-based hydrogel beads typically feature large pore sizes, providing numerous adsorption sites, which makes them well suited for wastewater treatment. Additionally, this paper examines the recent applications of chitosan-based hydrogel beads in food preservation, medicine, and environmental protection. Starting with the materials and methods for preparing chitosan-based hydrogel beads, this paper delves into their applications in food preservation, biomedicine, and environmental protection, offering insights for future developments and applications of chitosan-based hydrogel beads and fostering further innovation and advancement in this field. Full article

A robust experimental-based vehicle drive system model and parameters tuned to match the real-world performance of the electro-mechanical systems is presented. The model is based on battery electric vehicle systems, focusing on the individual components of the drive system. The model includes motors, a battery pack, a driveline, and a DC-DC converter. Based on the collected empirical data using an on-board data acquisition system, and fine-tuning the critical vehicle parameters to align the simulation with the empirical data, stationary and drive cycle tests were designed and performed to replicate standard day-to-day driving conditions. Performance metrics such as the power consumption, the state of charge and the range were employed for the model validation. The validated model was then used for the performance study at different operating temperatures. The results of the study demonstrate that the model successfully mirrored the performance of the powertrain under various conditions and lined up with existing research work, providing a valuable tool for further research and development in battery electric vehicle technology. Full article

Nuclear physics provides a natural laboratory for studying two kinds of fermions: protons and neutrons. These particles share similarities in mass and strong nuclear interactions, which are often described by isospin symmetry. However, isospin is not a good quantum number due to the differences between protons and neutrons in charge and quark mass. These differences become more pronounced as we approach or move beyond the dripline, affecting the structures and decay properties of mirror nuclei. To explore these intriguing phenomena, researchers have developed novel theoretical frameworks. In this article, we review the results from the Gamow shell model and Gamow coupled-channel, which account for the mirror symmetry breaking influenced by nuclear forces and continuum effects. Specifically, we discuss the recently observed mirror asymmetries in nuclei at the boundaries of the nuclide landscape and their theoretical explanations. We examine the breaking of mirror symmetry in the spectra of $N=8$ isotones versus $Z=8$ isotopes, as well as the decay properties of the ²²Al-²²F mirror pair. Such studies enhance our understanding of strong interactions and the behavior of open quantum systems. Full article

Silver nanoparticle-coated multi-walled carbon nanotube (Ag/MWNT) composites were prepared using a chemical plating method that effectively controls the overgrowth of silver nanoparticles, ensuring uniform particle size. Functionalization of the carbon nanotube surface with numerous functional groups facilitates the binding of silver ions to multi-walled carbon nanotubes (MWNTs). This process results in Ag/MWNT composites with a uniform distribution of silver nanoparticles, prepared through reduction via the silver mirror reaction. The impact of dispersants and reducing agents on the silver coating of carbon nanotubes was studied. The results revealed the formation of negatively charged functional groups (-COOH, -OH, -C=O, and -NH2) on the nanotube surface. These groups acted as nucleation sites for the formation of silver nanoparticles. These groups acted as nucleation sites for the formation of silver nanoparticles. Simultaneously, the Ag/MWNT composites demonstrated effective dispersion within the matrix, improving the electrical conductivity of the electronic paste by 32.1% and 33.1%. This improvement was attributed to the forming of a conductive pathway within the silver-modified composite. Ag/MWNT composites within the paste system improved interfacial contact between fillers and the matrix, enhancing their potential applications in thermal interface materials. Full article

Based on the thermal phase structure of pure SU(2) quantum Yang–Mills theory, we describe the electron at rest as an extended particle, a droplet of radius $r_0\sim a_0$, where $a_0$ is the Bohr radius. This droplet is of vanishing pressure and traps a monopole within its bulk at a temperature of $T_c=7.95$ keV. The monopole is in the Bogomolny–Prasad–Sommerfield (BPS) limit. It is interpreted in an electric–magnetically dual way. Utilizing a spherical mirror-charge construction, we approximate the droplet’s charge at a value of the electromagnetic fine-structure constant $\alpha$ of ${\alpha }^{-1}\sim 134$ for soft external probes. It is shown that the droplet does not exhibit an electric dipole or quadrupole moment due to averages of its far-field electric potential over monopole positions. We also calculate the mixing angle ${\theta }_{\mathrm{W}}\sim 30°$, which belongs to deconfining phases of two SU(2) gauge theories of very distinct Yang–Mills scales (${\Lambda }_{\mathrm{e}}=3.6$ keV and ${\Lambda }_{\mathrm{CMB}}\sim {10}^{-4}$ eV). Here, the condition that the droplet’s bulk thermodynamics is stable determines the value of ${\theta }_W$. The core radius of the monopole, whose inverse equals the droplet’s mass in natural units, is about 1% of $r_0$. Full article