Research Institute of Precision Instruments (Russia)

As next-generation quasi-solid-state ionic thermoelectric materials, ionogels show great potential in low-grade waste heat recovery and efficient energy management, with their thermoelectric performance stemming from cation-anion diffusion rate differences under thermal gradients. In this study, a PVDF-HFP-based ionogels, achieving a thermopower of 23.7mVK-1 and a power density of 102.8µWm-2K-2 by manipulating ion-ion interactions is developed. Interestingly, precise control of the temperature difference, leading to nonlinear temperature-voltage characteristics. By doping a series of cations with different properties such as charge quantity and ionic radius, the ion-ion interactions are analyzed to explore the influencing mechanism on the nonlinear feature arising from the dynamic reconstruction of ion concentration. This feature facilitates thermal switching for overheat protection in electronics. A device with 18 ionogel units is fabricated, achieving 2.09V output and dynamically controlling an LED. This work reveals the role of cation doping in regulating thermoelectric properties from the perspectives of ion-ion interactions and demonstrates the application of ionogels in thermal management via nonlinear thermal response.

Abstract Output optical characteristics of miniature highly stable hybrid integrated lasers were experimentally investigated. The devices are assembled in an industrial form factor using a multi-frequency semiconductor laser coupled with an external microring resonator (MRR). An expression for the coupling coefficient between the laser diode and the ring resonator is derived, taking into account the butt coupling efficiencies and reflection from the MRR. For two lasers with different MRRs the level of low-frequency thermorefractive noise is estimated and the instantaneous linewidth values are calculated and experimentally measured, yielding 200 Hz and 900 Hz, which are comparable to those of best commercially available analogues. The good agreement between theoretical and experimental data confirms the validity of the model used.

Abstract Large-scale spectroscopic surveys rely on thousands of densely packed fiber positioners to reconfigure between fields, where overlapping workspaces introduce a risk of mechanical collisions. Existing approaches typically separate target assignment from collision avoidance, leading to suboptimal performance, while real-time collision detection remains computationally expensive. In this work, we present an integrated framework for collision-aware field reconfiguration that combines three key innovations. First, a collision-aware target assignment strategy is introduced to minimize potential conflicts during allocation. Second, a segmented motion planning approach based on safety zones is developed to guide positioners through collision-free trajectories under dense packing conditions. Third, a lightweight real-time collision detection algorithm monitors deviations with low computational overhead. The framework is evaluated using a configuration modeled on the Large Sky Area Multi-Object Fiber Spectroscopic Telescope. Simulation results demonstrate that the proposed method decreases collision incidence by a factor of 2–10 while maintaining target allocation efficiency. The framework is readily applicable to other θ – φ fiber positioning systems, offering a practical and hardware-independent solution to enhance survey performance.

TaIrTe4, a time-reversal symmetric Weyl semimetal with the allowed minimum Weyl points, has sparked considerable attention and is appealing for a myriad of intriguing physical phenomena, including chiral anomaly, nonlinear Hall effect, dual quantum spin Hall insulator, and superconductivity. However, the electron–phonon coupling central to understanding the fundamental properties remains largely unexplored. In this work, we demonstrate the tell-tale signature of electron–phonon coupling in the type-II Weyl semimetal TaIrTe4 employing temperature-dependent Raman spectroscopy. Our results reveal that the temperature-dependent energy and lifetime of A1 phonon mode at ∼172 cm−1 diverge from the anharmonic model, evidencing the dominated role of phonon–electron rather than phonon–phonon scattering in phonon decay. The theoretically calculated electron–phonon coupling matrix element of the A1 mode is 0.39 eV, indicating substantial coupling to the electronic state. Our findings provide meaningful insights into understanding the fascinating physical properties and quantum phenomena of Weyl semimetal TaIrTe4.

Plasmodium falciparum is a unicellular eukaryotic pathogen responsible for the majority of malaria-related fatalities. Plasmodium belongs to the phylum Apicomplexa and like most members of this phylum, contains a non-photosynthetic plastid called the apicoplast. The apicoplast has its own genome, which is replicated by a dedicated apicoplast replisome. Unlike other cellular replisomes, the apicoplast replisome uses a single DNA polymerase (apPol) for copying the apicoplast DNA. Being the only DNA polymerase in the apicoplast, apPol is expected to multitask, catalysing both replicative and lesion bypass synthesis. Replicative synthesis typically relies on a restrictive active site for high accuracy while lesion bypass requires an open active site. This raises the question how does apPol combine the structural features of multiple DNA polymerases in a single protein. Using single particle electron cryomicroscopy (cryoEM), we have solved the structures of apPol bound to its DNA and nucleotide substrates in five pre-chemistry conformational states, allowing us to describe the events leading up to nucleotide incorporation and answer how apPol incorporates features of multiple polymerases. We found that, unlike most replicative polymerases, apPol can accommodate a nascent base pair with the fingers in an open configuration, which might facilitate the lesion bypass activity. In the fingers open state we identified a nascent base pair checkpoint that can preferentially select a Watson-Crick base pair, an essential requirement for replicative synthesis. Taken together these structural features explain how apPol may balance replicative and lesion bypass synthesis.

Metasurfaces, ultrathin structures composed of subwavelength optical elements, have revolutionized light manipulation by enabling precise control over electromagnetic waves’ amplitude, phase, polarization, and spectral properties. Concurrently, computational imaging leverages algorithms to reconstruct images from optically processed signals, overcoming the limitations of traditional imaging systems. This Perspective explores the synergistic integration of metaoptics and computational imaging, “metaoptic computational imaging”, which combines the physical wavefront shaping ability of metasurfaces with advanced computational algorithms to enhance imaging performance beyond conventional limits. We discuss how metaoptic computational imaging addresses the inherent limitations of single-layer metasurfaces in achieving multifunctionality without compromising efficiency. By treating metasurfaces as physical preconditioners and codesigning them with reconstruction algorithms through end-to-end (inverse) design, it is possible to jointly optimize the optical hardware and computational software. Advanced applications and new frontiers in the field enabled by metaoptic computational imaging are highlighted, including phase imaging and quantum state measurement.

Passive Fourier transform infrared spectroscopy, used to detect chemical pollutants in the air, works with extremely weak signals with complex and varying background interference. This significantly challenges gas identification in terms of precision. Consequently, limited research progress has been made in this area. To address this issue, this study proposes a model that leverages the Transformer, a self-attention-based neural network, and a coattention mechanism for gas identification. The architecture of this model facilitates joint feature learning and fusion, rendering the prediction performance robust to background interference. Extensive experiments demonstrate its significant improvements and feasibility, underlining the potential application in hazardous gas warning systems.

The light curves for almost 50 thousand stars with magnitudes $$m\in[11\overset{\textrm{m}}{.}5,19\overset{\textrm{m}}{.}5]$$ have been obtained over 2.5 years at SAO RAS in the process of conducting an exoplanet survey in roughly $$1\overset{\circ}{.}5$$ -sized fields around the white dwarfs WD 0009 $$+$$ 501 and GRW $$+$$ 708247. In this paper we present a catalog of variable stars that have been found in the considered regions. Periodogram analysis was used as the main variation search method. The catalog includes 150 periodic variable stars: 113 of them have been known previously, and for the remaining 37 variations have been discovered for the first time. These stars were classified according to the nature of the variations into four eclipsing variable and three pulsating types, as well as rotating stars. We present the periods and variation amplitudes in the range of $$P\in[0\overset{\textrm{d}}{.}036,32\overset{\textrm{d}}{.}14]$$ and $$\Delta m\in[0\overset{\textrm{m}}{.}0064,1\overset{\textrm{m}}{.}45]$$ , determined from the investigated data.