bluuebunny/crossref_metadata_2025 huggingface dataset:
Surface plasmon-enhanced photodetection of monolayers MoS2 on an ion beam modified functional substrate
Authors: Lu Shijia , Chen Jiamin , Yang Fan , Han Huangpu , Li Xiangyang , Chen Linlin , Wu Yuhao , He Bin , Chai Guangyue , Ruan Shuangchen , Xiang Bingxi
Published: November 2022

Monolayer molybdenum disulfide (1L-MoS2) is considered a potential optoelectronic device material due to its ultrathin and direct bandgap properties. However, the absorption of incident light by 1L-MoS2 has shown to be relatively low and is not sufficient to implement high photoelectric conversion efficiency, limiting its practical applications in photodetectors. Due to the local surface plasmon resonance effect, the integration of plasma nanoparticles (NPs) with 2D materials may provide a promising method for enhancing light–matter interactions. Nevertheless, MoS2 may undergo fold deformation when transferred to the plasma structure when prepared via conventional strategies, resulting in the introduction of larger defects. In this work, we reported on a photodetector with enhanced MoS2 photoresponsivity on a flat plasmon functional substrate, in which the Ag NPs were embedded into fused silica (SiO2) by ion implantation. Using MoS2/Ag NPs:SiO2 architecture, the photocurrent of the MoS2-based photodetector was significantly improved under incident light of 375, 532, and 635 nm, with a maximum increase of 72.8 times, while the response time also decreased to a certain extent. Furthermore, the plasma functional substrate had the advantages of environmental stability and repeatable recycling, allowing it to be easily integrated with different 2D materials. Thus, this work offered a viable path for realizing efficient photodetectors based on 2D material.
Insights into propagating surface plasmons in Ag–Cu alloy thin films: Enhancement of spin angular momentum of light
Authors: Bandaru Pravallika , Bhattacharyya Saswata , Dutta-Gupta Shourya
Published: November 2022

Surface plasmon polaritons (SPPs) can be supported by metal–dielectric interfaces and have been exploited for various applications. Typically, most studies deal with plasmons excited in pure metallic films or homogenous alloy thin films and the understanding of plasmon behavior in films with complex microstructures is limited. In this work, we numerically study the surface plasmons that are supported at the interface of an Ag–Cu alloy film that undergoes spinodal decomposition to produce a two-phase microstructure, when an initially compositionally homogenous alloy film (with composition within spinodal limits) is processed within the miscibility gap. We use phase-field simulated spinodally decomposed microstructures for our optical simulations to study the effect of microstructure on propagating surface plasmons in Ag–Cu alloy films. We demonstrate that the far-field response is governed principally by the composition of the alloy film and is not affected by the microstructural feature size. On the contrary, near-fields are strongly dependent on the microstructure and composition of the films. The origin of inhomogenous fields is demonstrated to be the result of constructive and destructive interference of SPPs. Finally, we demonstrate the enhancement of both transverse and longitudinal components of spin angular momentum in these phase-separated alloy films. The longitudinal components can be enhanced by more than a hundred times in the alloy films as compared to the pure metal films. This study paves the way for exploiting multi-phase alloy thin films for applications in sensing, nanomanipulation, and light modulation.
Goos–Hänchen shift of electron waves reflected by 8-Pmmn borophene np junctions
Authors: Zhang Chao , Yang Jin , Zhang Shu-Hui , Yang Wen
Published: November 2022

Electron optics introducing the optical concepts into the electronic system unifies the propagation and interference behaviors of different waves and promises nontrivial electronic applications. Due to the high mobility of massless Dirac fermions (MDFs), Dirac materials are suitable for the exploration of optics-like phenomena, in which the Goos–Hänchen shift is an outstanding example. The Goos–Hänchen shift has been studied very well for isotropic MDFs, e.g., in graphene, the relevant generalization to anisotropic MDFs is interesting but lacking. Here, we study the Goos–Hänchen shift of the reflected MDFs by np junctions based on 8-Pmmn borophene, in which MDFs are tilted. The Goos–Hänchen shift of tilted MDFs has a strong dependence on the junction direction, providing an additional tunability. Accounting for two valleys coupled by the time-reversal symmetry, the valley-contrasting Goos–Hänchen shift is demonstrated, this feature favors the use of 8-Pmmn borophene np junctions in valleytronics. This study is helpful to understand the anomalous shift of tilted MDFs along the longitudinal interface of np junctions, and implies the potential applications in valleytronics of 8-Pmmn borophene junctions.
Design of a gradient epsilon-near-zero refractory metamaterial with temperature-insensitive broadband directional emission
Authors: McSherry Sean , Lenert Andrej
Published: November 2022

Gradient epsilon-near-zero (ENZ) metamaterials offer broadband directional control over thermal emission. Implementing this approach using materials that remain stable in harsh thermo-chemical environments would allow it to be broadly deployed in thermal photonics. Our prior work showed that heterostructures of rock salt MgO and perovskite BaZr0.5Hf0.5O3 (BZHO) are stable up to 1100 °C in air, with no discernible intermixing. In this work, we design a gradient ENZ metamaterial made from three lattice-matched refractory oxides: MgO, BZHO, and NiO. The miscibility of MgO and NiO makes it possible to linearly vary the ENZ frequency of the metamaterial layers. BZHO is used as a thin, interlayer diffusion barrier. We model the emissivity of our gradient ENZ metamaterial at 25 and 1000 °C to demonstrate that the spectral bandwidth of directional emission is preserved at high temperatures despite changes in the optical properties of each material. Finally, we discuss practical fabrication challenges associated with the back reflector and offer potential solutions based on advancements in hetero-integration. Overall, this work shows a pathway toward gradient ENZ metamaterials with ultrahigh-temperature stability.
Phonon-induced exciton weak localization in two-dimensional semiconductors
Authors: Glazov M. M. , Iakovlev Z. A. , Refaely-Abramson S.
Published: November 2022

We theoretically study the contribution of quantum effects to the exciton diffusion coefficient in atomically thin crystals. It is related to the weak localization caused by the interference of excitonic wavefunctions on the trajectories with closed loops. Due to the weak inelasticity of the exciton–phonon interaction, the effect is present even if the excitons are scattered by long-wavelength acoustic phonons. We consider exciton interaction with longitudinal acoustic phonons with linear dispersion and flexural phonons with quadratic dispersion. We identify the regimes where the weak localization effect can be particularly pronounced. We also briefly address the role of free charge carriers in the exciton quantum transport and, within the self-consistent theory of localization, the weak localization effects beyond the lowest order.
Electrochemistry from the atomic scale, in the electronically grand-canonical ensemble
Authors: Lindgren Per , Kastlunger Georg , Peterson Andrew A.
Published: November 2022

The ability to simulate electrochemical reactions from first-principles has advanced significantly in recent years. Here, we discuss the atomistic interpretation of electrochemistry at three scales: from the electronic structure to elementary processes to constant-potential reactions. At each scale, we highlight the importance of the grand-canonical nature of the process and show that the grand-canonical energy is the natural thermodynamic state variable, which has the additional benefit of simplifying calculations. We show that atomic forces are the derivative of the grand-potential energy when the potential is fixed. We further examine the meaning of potential at the atomic scale and its link to the chemical potential and discuss the link between charge transfer and potential in several situations.
Inertial motion on the earth’s spheroidal surface
Authors: Edwards Boyd F. , Pankey Cade , Edwards John M.
Published: November 2022

As seen by an observer in the rotating frame, the earth’s small spheroidal deformations neutralize the centrifugal force, leaving only the smaller Coriolis force to govern the “inertial” motion of objects that move on its surface, assumed smooth and frictionless. Previous studies of inertial motion employ weakly spheroidal equations of motion that ignore the influence of the centrifugal force and yet treat the earth as a sphere. The latitude dependence of these equations renders them strongly nonlinear. We derive and justify these equations and use them to identify, classify, name, describe, and illustrate all possible classes of inertial motion, including a new class of motion called circumpolar waves, which encircle both poles during each cycle of the motion. We illustrate these classes using CorioVis, our freely available Coriolis visualization software. We identify a rotational/time-reversal symmetry for motion on the earth’s surface and use this symmetry to develop and validate closed-form small-amplitude approximations for the four main classes and one degenerate class of inertial motion. For these five classes, we supply calculations of experimentally relevant frequencies, zonal drifts, and latitude ranges.
High-temperature multiferroic magnetoelectric sensors
Authors: Yuan Guoliang , Xu Rukai , Wu Hanzhou , Xing Yisong , Yang Chen , Zhang Rui , Tang Wenbin , Wang Yiping , Wang Yaojin
Published: November 2022

Magnetoelectric (ME) sensors are an important tool to detect weak magnetic fields in the industry; however, to date, there are no high-quality ME sensors available for high-temperature environments such as engines, deep underground, and outer space. Here, a 0.364BiScO3–0.636PbTiO3 piezoelectric ceramic and Terfenol-D alloy with a Curie temperature of 450 and 380 °C, respectively, were bonded together by an inorganic glue to achieve a high-temperature ME sensor. The ceramic shows a piezoelectric d33 coefficient of 780 pC/N at 420 °C, and the inorganic glue has a high maximum stress of 9.12 MPa even at 300 °C. As a result, the sensor exhibits the maximum ME coefficient αE of 2.008, ∼1.455, and ∼0.906 V cm−1 Oe−1 at 20, 200, and 350 °C, respectively. Most importantly, the magnetic field detecting precision is as small as 42 nT at 20–350 °C. The ME sensor provides an effective solution for the detection of weak magnetic fields in harsh environments.
Understanding the diffusive transport of nanoparticles in agarose hydrogels
Authors: Xue Chun-Dong , Qu Heng-Chao , Zheng Guo-Shuang , Qin Kai-Rong , Zhao De-Wei
Published: November 2022

The enhanced delivery of nanoparticle (NP) drugs in the human system is a revolutionary approach for various diseases, e.g., cancer therapy, in which nanoparticle diffusion is one of the main routes of transport. The diffusive transport of nanoparticles in complex tumor microenvironments is intriguing, while its complete understanding is still nascent. Herein, we experimentally report a systematic study of nanoparticle diffusion in model porous media, i.e., agarose (AG) hydrogels. By examining both the time-averaged and ensemble-averaged mean square displacements (MSDs), the heterogeneous and spatially dependent mobility, as well as the significant hydrodynamic damping effect, are identified. The concept of ergodicity breaking (EB) is employed and correlated with the measured non-Gaussian displacement probability distributions (DPDs). The non-Gaussian profile is clarified to be attributed to the superposition of the coexisted Gaussian and non-Gaussian motions of the individual nanoparticles. Furthermore, the interstitial viscosity is found to only affect the probed heterogeneity temporarily but never modify the intrinsic non-ergodicity of the porous media. Our results give a comprehensive understanding of anomalous diffusion in spatially heterogeneous porous media and could provide the imperative knowledge to improve drug delivery in physiological media.
Photoacoustic imaging of tumor vascular involvement and surgical margin pathology for feedback-guided intraoperative tumor resection
Authors: Zhang Zhenhui , Mu Gen , Wang Erqi , Cui Dandan , Yang Fei , Wang Zhiyang , Yang Sihua , Shi Yujiao
Published: November 2022

Surgery represents the mainstream therapeutic modality in oncology. Aggressive radical surgery to achieve no residual tumor would improve survival, which is mainly affected by vascular involvement and accuracy of judging the negative margin of tumor resection. However, there is currently no intraoperative tool that can simultaneously perform microscopic analysis of the peritumoral vasculature in vivo and the surgical margin pathology of the tumor ex vivo, which leads to the randomness of one-time complete resection of the tumor, and the patient may have to undergo secondary surgery. To address this critical need, we developed a 532/266 nm dual-wavelength photoacoustic (PA) microscopy imaging (532/266-PAI) system that enables both in vivo tumor regional vascular involvement analysis and pathological margin assessment of fresh ex vivo tumor samples. A mammary tumor animal model was established to mimic the process of tumor resection, from in vivo imaging vascular involvement of tumor to intraoperative judgment of negative tumor margins. It is proved that the 532/266-PAI technology can identify the tumor vascular involvement through vascular visualization, determine the surgical plan, and then judge whether the tumor is completely removed through ultraviolet PA (UPA) tumor pathological imaging. Re-excision and secondary margin evaluation are performed when margin positive is diagnosed in the intraoperation UPA imaging. The 266/532-PAI technique has great potential for complete tumor resection in surgical navigation.
Evolution of a single sessile droplet under the influence of the dielectric barrier discharge plasma actuator
Authors: Zuo Zi-chao , Zhang Xin
Published: November 2022

Ice accretion on airplane surfaces has been widely recognized as a significant safety threat, and corresponding investigations of anti-/de-icing technologies have experienced tremendous growth during the last two decades. Dielectric barrier discharge plasma actuators involve different characteristics, such as thermal, acoustic, and flow characteristics, which are well suited for reducing and preventing ice accretion on wing surfaces effectively and safely. However, the correlation between the droplet, as the core of ice formation, and the plasma actuator is still not very clear. In order to understand the anti-/de-icing mechanism of the plasma actuator further, the evolution of a single sessile droplet under the influence of a symmetrical plasma actuator is studied. Interestingly, the oscillation of the droplet is first observed on the initiation of the plasma actuator, which is quite different from the droplet variation under traditional heating or cooling. Then, the flow field inside the droplet under the effect of the induced flow field of the plasma actuator is first uncovered by using the particle image velocimetry system. Subsequently, the evolution process of droplet deformation, deformed droplet moving downstream, deformed droplet moving downstream and evaporating, and water film moving downstream and evaporating is revealed. In addition, the underlying mechanism of the evolution process of the droplet is discussed based on the different characteristics of the plasma actuator. This study provides an in-depth understanding of the correlation between the droplet and the plasma actuation and lay a foundation for proposing the optimized strategy of anti-/de-icing using plasma actuators.
Dispersive x-ray absorption spectroscopy for time-resolved in situ monitoring of mechanochemical reactions
Authors: Guilherme Buzanich Ana , Cakir C. Tufan , Radtke Martin , Haider M. Bilal , Emmerling Franziska , F. M. de Oliveira Paulo , Michalchuk Adam A. L.
Published: November 2022

X-ray absorption spectroscopy (XAS) provides a unique, atom-specific tool to probe the electronic structure of solids. By surmounting long-held limitations of powder-based XAS using a dynamically averaged powder in a Resonant Acoustic Mixer (RAM), we demonstrate how time-resolved in situ (TRIS) XAS provides unprecedented detail of mechanochemical synthesis. The use of a custom-designed dispersive XAS (DXAS) setup allows us to increase the time resolution over existing fluorescence measurements from ∼15 min to 2 s for a complete absorption spectrum. Hence, we here establish TRIS-XAS as a viable method for studying mechanochemical reactions and sampling reaction kinetics. The generality of our approach is demonstrated through RAM-induced (i) bottom-up Au nanoparticle mechanosynthesis and (ii) the synthesis of a prototypical metal organic framework, ZIF-8. Moreover, we demonstrate that our approach also works with the addition of a stainless steel milling ball, opening the door to using TRIS-DXAS for following conventional ball milling reactions. We expect that our TRIS-DXAS approach will become an essential part of the mechanochemical tool box.
Development and application of a duplex simple sequence repeat panel for outcrossing fertility evaluation in red clover (Trifolium pratense) under open-pollination conditions†
Authors: Huang Fan , Li Jun , Zhou Shengyan , Li Zhiyong
Published: November 2022

Context Red clover (Trifolium pratense L.) is an important legume forage in temperate agricultural zones. Evaluation of self- and cross-pollination fertility is important for setting up an effective breeding-program scale. However, the outcrossing rate of red clover under open-pollination conditions is not certain. Development of a reliable and time-saving marker system is needed to quantify and characterise outcrossing rates. Aim We aimed to develop a duplex PCR-based protocol based on a genome-wide simple sequence repeat (SSR) screen, and to determine the outcrossing rate of red clover under open-pollination environments. Methods We screened 209 SSR markers with pooled DNA samples of 60 plants from 20 red clover accessions, and selected 185 SSR markers that produced clear scorable bands for testing with 24 individual DNA samples to determine polymorphism. We selected 70 primer pairs, and then assembled a core set of 24 loci into 12 sets of duplex markers, which were used for outcrossing behaviour analysis of 60 maternal parents and their respective 22 half-sib progenies. Key results Mean polymorphic information content (PIC) for the 70 markers was 0.490 (range 0.117–0.878). Minimum, mean and maximum PIC values for the 24 markers constituting the 12 duplexes were 0.226, 0.594 and 0.781, respectively. The outcrossing rate was identified as 99.4% for red clover in a natural environment. Conclusion We successfully developed a duplex SSR-based PCR protocol consisting of 24 markers. This SSR system was applied to determine the outcrossing rate of red clover in a natural environment.
Genomic selection in beef cattle creates additional opportunities for embryo technologies to meet industry needs
Authors: Miller Stephen
Published: November 2022

The use of genotype information to improve the predictability of Expected Progeny Difference was first implemented in American Angus cattle in 2009 and has now grown to where over 50% of all registered calves are genotyped. Animals with only a genotype now have genetic prediction accuracy equivalent to eight or more progeny records across all traits. Reproductive technologies have also been widely adopted with approximately 50% of all calves born being the result of artificial insemination. Non-surgical embryo transfer started increasing in the mid 1990s with just over 10% of calves born being the result of embryo transfer since 2005. The number of embryos created with in vitro technologies has risen sharply since 2015 and now accounts for close to 30% of all ET calves. Genomics has enabled embryo technologies to be more impactful, as females can be selected with greater accuracy and sires can be used at earlier ages with moderate accuracy. Large numbers of females genotyped each year also increases the number of selection candidates, increasing the selection intensity. Genomics, combined with increased recording, also provides more information on females. This increases the spread in the estimated index values of current dams, identifying more elite dams for selection as embryo donors. The greater scope of female selection also contributes to better inbreeding management. Commercial animals genotyped could be targeted for oocyte harvesting at slaughter, creating opportunities for low cost high value beef embryos to be used in the beef on dairy segment of the industry.
Detections of house mice on Gough Island approach zero within days of aerial baiting
Authors: Samaniego Araceli , Stevens Kim L. , Perold Vonica , Oppel Steffen , McClelland Pete
Published: November 2022

Context House mice (Mus musculus) on temperate Gough Island (6500 ha) are known for their large size, boldness, and tendency to kill large prey such as albatross chicks and even adults. To remove this threat, a mouse eradication operation was implemented in June–August 2021. How mice react to bait during eradications is not well understood, so we capitalised on this operation and conducted the first study with wild house mice during an actual eradication. Aim To document how rapidly mouse activity declined after application of rodent bait, to improve eradication guidelines. Methods We set up a monthly monitoring regime using 10 trail cameras without lures, active for three nights in various habitats around a research station, because this area supported the highest abundance of mice and was logistically feasible. Monitoring commenced before the mouse eradication operation (January–May 2021), and continued when rodent bait was spread (from June 2021), when mouse activity was monitored for 17 consecutive nights, starting the day before baiting. In addition, an increasing number of cameras (up to 15) associated with lures were set further afield in July–August to detect survivors. Key results In the months before bait application, mean daily mouse activity was 3.2 detections/camera (range: 0–56 detections/camera). Immediately after the first bait application, detection rates declined dramatically, from 9.6 to zero detections/camera per day on Day 4 post-baiting. From 1 week post-baiting, mouse detections were extremely rare on both cameras with and without lures. Our last mouse record, 27 days after the first bait application, may be related to initial rapid bait disappearance. Opportunistic camera traps first detected surviving mice 6 months after the first bait drop. Conclusions The rapid decline in detections suggests that most mice consumed bait as soon as it became available, which is faster than what laboratory trials suggest. Future similar operations can expect that mouse activity will decline sharply within 1 week, although some mice may survive longer. Implications Documenting similar declines in mouse activity using cameras could inform operational decisions such as timing of a second bait application or non-target monitoring on future eradication projects. Cameras, particularly with attractive lures, are an effective addition to the mouse detection toolkit, and facilitated a timely confirmation of eradication outcome.
SMC protein RecN drives RecA filament translocation for in vivo homology search
Authors: Chimthanawala Afroze , Parmar Jyotsana J. , Kumar Sujan , Iyer Krishnan S. , Rao Madan , Badrinarayanan Anjana
Published: November 2022

While the molecular repertoire of the homologous recombination pathways is well studied, the search mechanism that enables recombination between distant homologous regions is poorly understood. Earlier work suggests that the recombinase RecA, an essential component for homology search, forms an elongated filament, nucleating at the break site. How this RecA structure carries out long-distance search remains unclear. Here, we follow the dynamics of RecA after induction of a single double-strand break on the
Caulobacter
chromosome. We find that the RecA-nucleoprotein filament, once formed, rapidly translocates in a directional manner in the cell, undergoing several pole-to-pole traversals, until homology search is complete. Concomitant with translocation, we observe dynamic variation in the length of the filament. Importantly in vivo, the RecA filament alone is incapable of such long-distance movement; both translocation and associated length variations are contingent on action of structural maintenance of chromosome (SMC)-like protein RecN, via its ATPase cycle. In summary, we have uncovered the three key elements of homology search driven by RecN: mobility of a finite segment of RecA, changes in filament length, and ability to conduct multiple pole-to-pole traversals, which together point to an optimal search strategy.
Leveraging a natural murine meiotic drive to suppress invasive populations
Authors: Gierus Luke , Birand Aysegul , Bunting Mark D. , Godahewa Gelshan I. , Piltz Sandra G. , Oh Kevin P. , Piaggio Antoinette J. , Threadgill David W. , Godwin John , Edwards Owain , Cassey Phillip , Ross Joshua V. , Prowse Thomas A. A. , Thomas Paul Q.
Published: November 2022

Invasive rodents are a major cause of environmental damage and biodiversity loss, particularly on islands. Unlike insects, genetic biocontrol strategies including population-suppressing gene drives with biased inheritance have not been developed in mice. Here, we demonstrate a gene drive strategy (
t
CRISPR
) that leverages super-Mendelian transmission of the
t
haplotype to spread inactivating mutations in a haplosufficient female fertility gene (
Prl
). Using spatially explicit individual-based in silico modeling, we show that
t
CRISPR
can eradicate island populations under a range of realistic field-based parameter values. We also engineer transgenic
t
CRISPR
mice that, crucially, exhibit biased transmission of the modified
t
haplotype and
Prl
mutations at levels our modeling predicts would be sufficient for eradication. This is an example of a feasible gene drive system for invasive alien rodent population control.
Variants of the myosin interacting-heads motif
Authors: Padrón Raúl , Dutta Debabrata , Craig Roger
Published: November 2022

Under relaxing conditions, the two heads of myosin II interact with each other and with the proximal part (S2) of the myosin tail, establishing the interacting-heads motif (IHM), found in myosin molecules and thick filaments of muscle and nonmuscle cells. The IHM is normally thought of as a single, unique structure, but there are several variants. In the simplest (“canonical”) IHM, occurring in most relaxed thick filaments and in heavy meromyosin, the interacting heads bend back and interact with S2, and the motif lies parallel to the filament surface. In one variant, occurring in insect indirect flight muscle, there is no S2–head interaction and the motif is perpendicular to the filament. In a second variant, found in smooth and nonmuscle single myosin molecules in their inhibited (10S) conformation, S2 is shifted ∼20 Å from the canonical form and the tail folds twice and wraps around the interacting heads. These molecule and filament IHM variants have important energetic and pathophysiological consequences. (1) The canonical motif, with S2–head interaction, correlates with the super-relaxed (SRX) state of myosin. The absence of S2–head interaction in insects may account for the lower stability of this IHM and apparent absence of SRX in indirect flight muscle, contributing to the quick initiation of flight in insects. (2) The ∼20 Å shift of S2 in 10S myosin molecules means that S2–head interactions are different from those in the canonical IHM. This variant therefore cannot be used to analyze the impact of myosin mutations on S2–head interactions that occur in filaments, as has been proposed. It can be used, instead, to analyze the structural impact of mutations in smooth and nonmuscle myosin.
Local atomic-morphology-resolved edge states in twisted bilayer graphene nanoribbons
Authors: Shao Huaihua , Zhou Guanghui
Published: November 2022

We study the properties of edge states for a selected (10,1)[(4,3)] twisted bilayer graphene (TBG) nanoribbon with minimal edges but a majority of zigzag edges. By using the tight-binding and Green’s function methods, we find a remarkable rule of a local electronic transfer for the edge states. As the energy away from the Fermi level, the transfer is in the order of convex AB-, concave AB-, concave AA- and convex AA-stacked regions of the ribbon curve edges. We illustrate that this rule comes from the difference in interlayer couplings among the four types of local geometries at edges. Further, an in-plane transverse electric field can rearrange the edge bands and enlarge the energy regimes, leading to the lowest energy states modified from AB-stacked edge states to AA-stacked ones. The realignment of the edge bands results from the interplay between the interlayer coupling and the potential difference induced by the transverse electric field, which results in different bonding and antibonding edge states, i.e. the edge bands. In contrast, the total energy regime of the edge bands remain nearly unchanged under a relative strong off-plane perpendicular electric field, and the typical AA-stacked edge states are still maintained even the rotational symmetry of two layers is broken. Until a sufficiently strong value, the TBG nanoribbon tends to behave as two noninteracting monolayer ribbons except for a band distortion in low-energy regime. The conductance spectra reflects the edge bands well. We also discussed the influence of edge defects in the TBG nanoribbon on transport properties. It is found that the contributed conductance of each type of edge states shows different degrees of suppression for a monatomic vacancy in the corresponding region of edges.
Exact mobility edges in quasiperiodic systems without self-duality
Authors: Cai Xiaoming , Yu Yi-Cong
Published: November 2022

Mobility edge (ME), a critical energy separating localized and extended states in spectrum, is a central concept in understanding localization physics. However, there are few models with exact MEs, and their presences are fragile against perturbations. In the paper, we generalize the Aubry-André-Harper model proposed in (Ganeshan et al 2015 Phys. Rev. Lett.
114 146601) and recently realized in (An et al 2021 Phys. Rev. Lett.
126 040603), by introducing a relative phase in the quasiperiodic potential. Applying Avila’s global theory, we analytically compute localization lengths of all single-particle states and determine the exact expression of ME, which both significantly depend on the relative phase. They are verified by numerical simulations, and physical perception of the exact expression is also provided. We show that old exact MEs, guaranteed by the delicate self-duality which is broken by the relative phase, are special ones in a series controlled by the phase. Furthermore, we demonstrate that out of expectation, exact MEs are invariant against a shift in the quasiperiodic potential, although the shift changes the spectrum and localization properties. Finally, we show that the exact ME is related to the one in the dual model which has long-range hoppings.
Online detection of measurement error in three-phase CVT based on equivariant adaptive source separation
Authors: Zhang Mengjuan , Zhang Zhu , Fan Min , Ding Lijian
Published: November 2022

As a key device for signal acquisition in power systems, the capacitor voltage transformer (CVT) has been widely used in high-voltage power grids with a capacity of 110 kV and above. However, the long-term stability of error in its measurements is poor and requires effective detection work. The conventional method of regular offline detection has the problems of power failure and operation difficulty. An online method for identifying errors in measurements of the CVT based on equivariant adaptive source separation is proposed in this paper. Under normal operation, the secondary output information of three-phase CVT is linearly correlated, and equivariant adaptive separation via independence (EASI) is used to analyze the correlation of data matrix. By constructing the main space and residual space, the primary voltage fluctuation is separated from the metering error. According to the separated signal characterizing the measurement error information, the standard quantity is established to realize the online detection of measurement error of three-phase CVT. In view of the non-stationary time-varying characteristics of power system operation, the data model is continuously updated according to successively acquired, which effectively improves the accuracy of the state assessment of the three-phase CVT. The simulation and experimental results show that the proposed method outperforms the independent component analysis (ICA), which can well meet the requirements of 0.2-level accuracy and have an evaluable change in amplitude that is better than 0.05%.
Eco-friendly MA3Bi2I9 perovskite thin films based ammonia sensor
Authors: Bhosale M K , Kazi A I , Pawar K K , Shingate R S , Kadam A D , Patil N J , Sheikh Arif D
Published: November 2022

Organic–inorganic perovskite halides (OIPH) have emerged as a wonder material with growing interest in sensors detecting various toxic gases. However, lead toxicity represents a potential obstacle, and therefore finding lead-free cost-effective compatible materials for gas sensing applications is essential. In this work, methylammonium bismuth iodide i.e. (CH3NH3)3Bi2I9 (MABI) perovskite thin films-based ammonia (NH3) sensor was synthesized using an antisolvent-assisted one-step spin coating method. The MABI sensor shows a linear relationship between the responsivity and concentration of NH3 with excellent reversibility, high gas responsivity, and humidity stability. The MABI thin-film sensor exhibits a maximum gas response of 24%, a short response/recovery time i.e. 0.14 s /8.15 s and good reversibility at 6 ppm of NH3. It was observed that MABI thin films based sensors have excellent ambient stability over a couple of months. This work reveals that it is feasible to design high-performance gas sensors based on environmentally-friendly Bi-based OIPH materials.
Particle-in-cell simulations of the direct-current argon breakdown process in the 10–300 kV range
Authors: Jin Biemeng , Chen Jian , Khrabrov Alexander V , Wang Zhibin , Xu Liang
Published: November 2022

Direct-current ionization breakdown in argon at very high voltage on the low-pressure branch of the Paschen curve is studied by means of kinetic simulation. The employed particle-in-cell/Monte Carlo collision model tracks the motion of electrons, ions and fast neutral atoms, as well as their collisions with the background gas. Secondary electron emission due to the bombardment by ions and fast atoms, as well as backscattering of different species on the electrode surfaces are also consistently accounted for. To validate the model, we compare the Paschen curve predicted by kinetic simulations against published experimental results as well against the prediction of a reduced (fluid) model. The model is then applied to predict, for the first time, the low-pressure branch of the Paschen curve for argon gas in the 10–300 kiloVolt range of applied voltage. One of the findings is the existence of a turning point on the Paschen curve at

V

b
r

≈
20

k
V

and

p
d

≈
0.08

T
o
r
r

⋅

c
m

, where

V

b
r

is the breakdown voltage and the reduced pressure

p
d

is the product of the gas pressure with the inter-electrode distance. According to our analysis, the presence of the turning point is due to the phenomena of electron and ion runaway in high electric field. We further investigate the role of the heavy species (i.e. ions and fast neutral atoms) in sustaining the Townsend discharge at high voltage and thus setting the breakdown threshold. Specifically, the role of fast atoms is significant over the entire low-pressure branch of the Paschen curve due to their contribution to both ionization and secondary electron emission. Also, the ions, as the precursor for the fast atoms, show an important influence on the latter process. The newly predicted low-pressure branch of the Paschen curve for argon at high voltage should provide an essential reference for the design of high-voltage devices, e.g. circuit breakers in electrical power transmission.
Spatio-temporal profile of atomic oxygen in a 1 kHz repetition atmospheric-pressure plasma jet in He–O2–H2O mixture
Authors: Nakagawa Yusuke , Horibe Hikari , Komuro Atsushi , Ono Ryo
Published: November 2022

Atomic oxygen (O) is one of the essential reactive species in plasma oxidation processes. We investigated the behavior of atomic oxygen in a 1 kHz-repetition pulsed plasma jet in atmospheric-pressure He/O2/H2O mixture. By two-photon absorption laser-induced fluorescence, the spatio-temporal profiles of O density were measured under various conditions. In the dry ([H2O]

⩽

100 ppm) condition, the rate of O production did not depend on the [O2] fraction in the range of [O2] = 275–8600 ppm. The analysis of the O-production rate indicates that the atomic oxygen in this plasma jet arises from electron-impact dissociation and quenching of O(1
D), similar to the O-production mechanism in radio-frequency plasma jet. The dependence of O-production in each discharge pulse (Δ[O]) on the discharge energy

E

d

and [O2] in the plasma region at dry condition is formulated as

[
Δ

O

]
(

c

m

−
3

)

/

E

d

(

m
J

)
=

1.3
×

10

15

×

{

1
−
exp
(
−
1.85
×

10

−
17

[

O
2

]
(

cm

-3

)
)

}

. The decay rate of atomic oxygen was not explained by self-recombination or ozone-generation reactions; it was consistent with the reaction rate of O + OH

→

O2 + H at [OH] =

2
×

10

13

 cm−3. This result suggests that the small amount of [OH] with 1013 cm−3 density is more responsible for O behavior than [O2] with large fraction of 1015 cm−3. We conducted a chemical reaction simulation considering the measured results of [O] and [OH] production, resulting in good agreement with the spatial distribution of [O]. Chemical reaction analysis revealed that the cyclic reproduction of OH via chain reaction with O and O2 is important, therefore a small amount of OH catalytically consumes atomic oxygen with two-order higher density.
Standing wave instability in large area capacitive discharges operated within or near the gamma mode
Authors: Lieberman M A , Kawamura E , Chabert P
Published: November 2022

Large-area capacitive discharges used for plasma deposition operate in a regime where both electromagnetic and secondary electron emission effects are important. The standing wave shortened wavelength in the presence of plasma depends on the sheath size, and in the γ mode, the secondary electron multiplication controls the sheath physics. Near the α-to-γ transition, and within the γ mode, the sheath width typically varies inversely with the discharge voltage, and large center-to-edge voltage (standing wave) ratios may exist. This can give rise to a standing wave instability, in which the central voltage of the discharge grows uncontrollably, for a given voltage excitation at the discharge edge. Using a simple model, we determine the discharge equilibrium properties, the linearized stability condition, and the nonlinear time evolution. For sufficiently large areas, we show that a discharge equilibrium no longer exists above a critical edge voltage at marginal stability.
Role of charge carriers in long-term kinetics of polyurethane electroactuation
Authors: Coativy G , Yuse K , Diguet G , Perrin V , Seveyrat L , Dalmas F , Livi S , Courbon J , Takana H , Cavaillé J Y
Published: November 2022

Previous work has shown that dielectrophoretic body forces resulting from permittivity and conductivity heterogeneities only partially contribute to the overall electromechanical deformation of segmented polyurethanes (PUs). In this work, we studied the experimental kinetics and electric current of PU thin films over a long time period (1–105 s) for different applied electric fields. Then, we thoroughly analyzed the drift behavior of electric carriers and its macroscopic effect using simple modeling and numerical simulation. The main assumption is that the macroscopic deformation results from the accumulation of electric charges near the electrodes, leading to local stretching. Assuming that the mobilities of negative and positive carriers are different, their migration towards the electrodes will have different kinetics. A preliminary simulation attempt using a single set of parameters, supports these assumptions, and leads to a correct bending amplitude and current evolution according to the applied electric field. Furthermore, the resulting compression is consistent with the observed electrostriction.
Non-equilibrium phonon distribution caused by an electrical current
Authors: Dwedari Magdulin , Brendel Lothar , Wolf Dietrich E
Published: November 2022

In an attempt to explain flash sintering experiments, it had been proposed that the electron–phonon coupling leads to a proliferation of short wave-length lattice vibrations in an electric field. In this paper we investigate this by solving two coupled Boltzmann equations, describing a free electron gas in an electric field scattering from a crystal lattice coupled to a heat bath. The electric field imposes cylindrical symmetry and drives the electrons and the phonons into a non-equilibrium steady state. We find that the phonon distribution shows a strong excess population at the Brillouin zone edge in the direction of the electric field. We argue analytically, that this can be traced back to the shifted Fermi sphere for the electrons. Furthermore, not only energy but also momentum is exchanged in the electron–phonon system, which defies any attempt at describing the system by a two-temperature model.
Spectroscopic investigations of detachment on the MAST Upgrade Super-X divertor
Authors: Verhaegh K. , Lipschultz B. , Harrison J.R. , Osborne N. , Williams A.C. , Ryan P. , Allcock J. , Clark J.G. , Federici F. , Kool B. , Wijkamp T. , Fil A. , Moulton D. , Myatra O. , Thornton A. , Bosman T.O.S.J. , Bowman C. , Cunningham G. , Duval B.P. , Henderson S. , Scannell R. , the MAST Upgrade team
Published: November 2022

We present the first analysis of the atomic and molecular processes at play during detachment in the MAST-U Super-X divertor using divertor spectroscopy data. Our analysis indicates detachment in the MAST-U Super-X divertor can be separated into four sequential phases: first, the ionisation region detaches from the target at detachment onset leaving a region of increased molecular densities downstream. The plasma interacts with these molecules, resulting in molecular ions (

D

2

+

and/or

D

2

−

→
D
+

D

−

) that further react with the plasma leading to molecular activated recombination and dissociation (MAR and MAD), which results in excited atoms and significant Balmer line emission. Second, the MAR region detaches from the target leaving a sub-eV temperature region downstream. Third, an onset of strong emission from electron–ion recombination (EIR) ensues. Finally, the electron density decays near the target, resulting in the bulk of the electron density moving upstream. The analysis in this paper indicates that plasma–molecule interactions have a larger impact than previously reported and play a critical role in the intensity and interpretation of hydrogen atomic line emission characteristics on MAST-U. Furthermore, we find that the Fulcher band emission profile in the divertor can be used as a proxy for the ionisation region and may also be employed as a plasma temperature diagnostic for improving the separation of hydrogenic emission arising from electron-impact excitation and that from plasma–molecular interactions. We provide evidences for the presence of low electron temperatures (≪0.5 eV) during detachment phases III–IV based on quantitative spectroscopy analysis, a Boltzmann relation of the high-n Balmer line transitions together with an analysis of the brightness of high-n Balmer lines.
Riemann surfaces for integer counting processes
Authors: Prolhac Sylvain
Published: November 2022

Integer counting processes increment the integer value at transitions between states of an underlying Markov process. The generator of a counting process, which depends on a parameter conjugate to the increments, defines a complex algebraic curve through its characteristic equation, and thus a compact Riemann surface. We show that the probability of a counting process can then be written as a contour integral on that Riemann surface. Several examples are discussed in detail.
Study on solar absorption-compression cascade refrigeration cycle based on temperature and humidity independent
Authors: You YiLin , Wang WenChao.
Published: November 2022

A new solar lithium bromide absorption - compression refrigeration cycle system was proposed for temperature and humidity independent control. MATLAB programming language is used to perform the thermal calculation of the new system, and the cycle characteristics of the typical day of the new system are analyzed. The influence of solar radiation intensity is analyzed. The results show that the new system can realize the cascade preparation and utilization of cooling capacity, and the optimal evaporation temperature makes the new system have higher performance.
Mean Optimization of High Penetration Energy System with Energy Storage Access
Authors: Ding Zhilin , Bu Wenping , Li Shaoyi , Feng Shuling , Wu Meng
Published: November 2022

In this paper, variables consisting of power, voltage and current in high penetration energy system are established to solve the matrix equation with energy storage access, taking the power supply of a 5-node system with 30% energy ratio wind power as an instance, the state of each node variable of the system was leveled by mean optimization method based on daily load curve, via calculating power flow, nodes voltage and current and evaluating corresponding output variable variances as evaluation index for optimization. The optimal effects of power flow, nodes voltage and current variables of the system before and after energy storage access were analyzed by simulation, and the variation and improvement of variance parameters were compared to verify the effectiveness and validation of the proposed method.
Disk anomaly detection for remote maintenance control system of natural gas pipeline based on multi-source domain transfer and incremental learning
Authors: Jing Xiao , Wang Lei , Shi Wei , Wang Ning
Published: November 2022

Accurate disk anomaly detection is of great significance for maintaining the safe and stable operation of the remote control system of natural gas pipelines. Most disk transfer algorithms use only a single-source domain model for offline transfer learning, resulting in lower classifier performance. This paper proposes a disk online anomaly detection algorithm combining transfer learning and incremental learning. A transfer learning algorithm based on data distribution similarity and dynamic index weighted ensemble is proposed. According to multiple source domain models and target domain model negative data in hyperspace, k neighbour data of each target domain negative data is extracted, and then different test criteria are adopted for each sub-model according to the number of target domain positive data, and index reweighting is performed according to the model detection capability. An incremental learning algorithm based on online automatic annotation is proposed. The data popped up by the sliding window is automatically marked at the current disk state, and the update period of the prediction model is dynamically adjusted according to the false detection rate and the missed detection rate. By setting three different experiments for comparison, the effectiveness and advanced nature of the method proposed in this paper are illustrated.