bluuebunny/crossref_metadata_2025 huggingface dataset:
Weighted ensemble learning for real‐time short‐term voltage stability assessment with phasor measurements data
Authors: Babaali Amir Hossein , Ameli Mohammad Taghi
Published: March 2023

Voltage stability assessment based on machine learning has become an important challenge in power systems. This paper presents real‐time short‐term voltage stability (STVS) assessment based on phasor measurement unit (PMU) data and machine learning (ML). The database is created through time series of measurement data to involve system time‐temporal and dynamics. Then multiple operating states of the power system are classified through the calculation of the Lyapunov exponent and dynamic voltage index according to the database. This paper presents a weighted combination of random forest (RF) and LightGBM (LGBM) classifiers to train a time‐series database. One of the main advantages of this paper is using the gradient concept in data preprocessing, which has enhanced performance metrics and reduced the defect of data noise. Also, hyperparameter optimization is conducted to improve machine performance. Studies on the IEEE 118bus and a real local grid (RLG) demonstrate that the proposed method improves the performance metrics such as accuracy and F1‐score. Also, this approach is robust against PMU data noise and topology changes in the network.
A lightweight network of near cotton‐coloured impurity detection method in raw cotton based on weighted feature fusion
Authors: Xu Tao , Ma Aisong , Lv Huan , Dai Yang , Lin Shoujin , Tan Haihui
Published: March 2023

The objective is to improve the recognition rate of white and near cotton‐coloured impurities in raw cotton against a single white visible light source background. A lightweight detection network model without anchor boxes based on improved YOLO v4‐tiny is proposed in this paper based on weighted feature fusion (WFF). The WFF strategy was used to improve the detection accuracy of the improved YOLO v4‐tiny algorithm. Meanwhile, to address the disadvantage that the anchor boxes obtained by the K‐means algorithm clustering do not have global features, the anchor‐free and tiny decoupled head schemes are used instead of the traditional coupled detection head. The improved algorithm was validated on the PASCAL VOC2012 dataset and the self‐built raw cotton impurity dataset collected by high‐speed camera. On the raw cotton impurity test set, compared to the original YOLO v4‐tiny model, the mean average precision (mAP) and frames per second (FPS) of the improved model increased by 10.35% and 6.9%, respectively. The proposed model detects white and near cotton‐coloured impurities with an accuracy of up to 98.78% and 98.00%. The experimental results show that the proposed method can effectively detect and identify impurities in raw cotton, which is of great practical significance for foreign matter detection and identification in cotton.
KM3NeT/ARCA: Status of construction and recent physics results
Authors: Biagi Simone
Published: March 2023

KM3NeT is a multi-site detector devoted to the detection and study of cosmic neutrinos and their sources in the Universe, and to the measurement of the neutrino oscillation parameters. Two underwater detectors are under construction in the Mediterranean Sea, ARCA (Portopalo di Capo Passero, Italy) and ORCA (Toulon, France), optimised respectively for neutrinos in the energy range of 1 TeV–100 PeV and 10 GeV–10 TeV. The mass construction of the detectors has started, and a long-term plan for the completion is in place. At the time of writing this article, 21 (14) detection units are already in operation in the ARCA (ORCA) site from a total of 230 (115). In these proceedings, the major milestones achieved for the construction of the ARCA telescope are discussed. The main physics results obtained with ARCA, in its partial configurations are reported. Finally, an overview of the expected performances of the full detectors will be given.
TeV emission from Gamma Ray Bursts, checking the hadronic model
Authors: Guetta Dafne , Gagliardini Silvia , Celli Silvia , Zegarelli Angela , Capone Antonio , Campion Stefano , DiPalma Irene
Published: March 2023

Gamma-Ray Bursts (GRBs) are the most luminous explosions in the Universe. Their luminous prompt emission makes them detectable from cosmological distances. Most GRBs have been detected below a few MeV, however at least a hundred GRBs have been detected at high (0.1 GeV) energies and observed up to tens of GeV with the Fermi Large Area Telescope (LAT). Some GRBs have been observed at (0.1–1) TeV by ground-based imaging atmospheric Cherenkov telescopes. To date, the high energy emission mechanism is not understood. In this paper we review the possible leptonic and hadronic mechanisms capable of producing the ∼ TeV emission detected in GRBs. In paricular we concentrate on the hadronic origin of this radiation component and discuss in detail the numerical simulation elaborated to reproduce the observed sub-TeV observations of GRB190114C.
Gravitational Waves and Black Holes
Authors: Ricci Fulvio
Published: March 2023

We summarise the present status of the gravitational wave detectors on the Earth.Then, we discuss some of the most intriguing results obtained during the last data collection O3. We will focus on the statistical distributionof the population of these compact objects and we will discuss a couple of potential tests to be carried on the on the Bekenstein-Hawking thermodynamics using the gravitational wave signals.
KM3NeT/ARCA Sensitivity to Starburst Galaxies
Authors: Ambrosone A. , Ibnsalih W.I. , Marinelli A. , Miele G. , Migliozzi P. , Musone M. R.
Published: March 2023

In this work, the expectations of the full detector KM3NeT/ARCA are presented for particular starburst galaxies signals. For the point-like search approach, we considered the most promising local starburst galaxies to be observed as point-like neutrino excesses: NGC 1068, the Small Magellanic Cloud and the Circinus Galaxy. In both cases, we provide the energy-integrated sensitivity for two ARCA building blocks in the energy range 100 GeV − 10 PeV. In the diﬀuse scenario, both track and shower events were considered. For the point like analysis, only νµ charge current events were taken into account. Interestingly, ARCA has the potential to constrain the selected phenomenological scenarios, providing evidence of the link between star-forming processes and hadronic emissions.
The Einstein Telescope: Status of the project
Authors: Chiummo Antonino
Published: March 2023

After the groundbreaking ﬁrst detection of Gravitational Waves by the LIGO/Virgo Collaborations, the design of the third generation of gravitation wave interferometric antennas has gained a substantial interest and momentum. The Cosmic Explorer in the US and the European Einstein Telescope (ET) are the instruments which will take the legacy of the current generation and further advance the reach of the GW antennas, both in terms of explored Universe and of type of accessible sources. The talk focused on the status of the design of the Einstein Telescope, its technical challenges and the expected implications to the Gravitational Wave Astronomy progress.

The paper reﬂects the content and the status of the ET project at the time of the talk given at RICAP22.
Digital speckle photography in the presence of displacement gradients
Authors: Schweickhardt León , Tausendfreund Andreas , Stöbener Dirk , Fischer Andreas
Published: March 2023

Digital speckle photography is a displacement field measurement method that employs laser speckles as surface markers. Since the approach requires only one reference image without a preparation of the sample and provides a fast, single-shot measurement with interferometric precision, the method is applied for in-process measurements in manufacturing engineering. Due to highly localized loads, higher-order displacement gradients occur in manufacturing processes and it is an open research question how these gradients affect the measurement errors of digital speckle photography. We simulate isotropic Gaussian surface topographies, apply a displacement field and then generate laser speckle patterns, which are evaluated with digital image correlation and subsequently the resulting random and systematic errors of the displacement field are analyzed. We found that the random error is proportional to the first-order displacement gradient and results from decorrelation of the laser speckles. The systematic error is mainly caused by the evaluation algorithm and is linearly dependent on the second-order gradient and the subset size. We evaluated in-process displacement measurements of laser hardening, grinding and single-tooth milling where we determined the relative error caused by displacement gradients to be below 2.5% based on the findings from the simulative study.
Lokaltherapie chronischer Wunden: Das M.O.I.S.T. Konzept
Authors: Dissemond Joachim , Assenheimer Bernd , Gerber Veronika , Kurz Peter , Läuchli Severin , Panfil Eva-Maria , Probst Sebastian , Traber Jürg , Strohal Robert
Published: March 2023

Die Behandlung von Patienten mit chronischen Wunden ist weiterhin eine interdisziplinär und interprofessionell relevante Herausforderung. Die Grundlage einer erfolgreichen Therapie der Betroffenen basiert auf der Behandlung der zugrunde liegenden, pathophysiologisch relevanten Erkrankungen. Zusätzlich sollte aber auch immer eine lokale Wundtherapie erfolgen, um die Wundheilung zu unterstützen und Komplikationen zu vermeiden. Um die Vielzahl von Wundprodukten besser strukturieren zu können, wurde durch eine multidisziplinäre Expertengruppe von WundDACH, dem Dachverband deutschsprachiger Fachgesellschaften, das M.O.I.S.T.-Konzept entwickelt. Hier beschreibt M das Exsudatmanagement (Moisture balance), O die Sauerstoffzufuhr (Oxygenation), I die Infektionskontrolle (Infection control), S die Unterstützung des Heilungsprozesses (Support) und T das Gewebemanagement (Tissue management).

Das M.O.I.S.T.-Konzept soll Therapeuten eine Hilfestellung bei der systematischen Planung und auch für die Edukation im Hinblick auf die Lokaltherapie von Patienten mit chronischen Wunden bieten. Hier wird nun das Update 2022 dieses Konzeptes erstmalig vorgestellt.
Quantification of Portal Vein Vascularization Using an Automated
Post-Processing Video Analysis Tool
Authors: Blank Valentin , Heni Maria , Karlas Thomas
Published: March 2023

Purpose Blood flow dynamics represent a diagnostic criterion for many
diseases. However, no established reference standard is available. In clinical
practice, ultrasound pulsed-wave Doppler (PW-Doppler) is frequently used to
assess visceral blood flow, despite its well-known limitations. A quantitative
analysis of conventional color Doppler patterns can be performed using an
innovative ultrasound-based algorithm (pixel flow analysis, PFA). This tool
already shows promising results in obstetrics, but the technique has not yet
been evaluated for portal venous blood flow assessment.

Methods This prospective exploratory research study evaluated the
applicability of PFA in the portal venous system. Measurements of portal venous
flow using PFA and PW-Doppler were compared in healthy volunteers (n=20)
and in patients with hepatic steatosis (n=10) and liver cirrhosis
(n=10).

Results In healthy volunteers (60% female, mean age 23 years, BMI
21.5 kg/m2 [20.4–23.8]), PFA and
PW-Doppler showed a strong positive correlation in fasting conditions
(r=0.69; 95% CI 0.36–0.87), recording a median blood
flow of 834 ml/min (624–1066) and
718 ml/min (620–811), respectively. PFA was also
applicable in patients with chronic liver diseases (55% female, age 65
years (55–72); BMI 27.8 kg/m2
(25.4–30.8)), but the correlation between PFA and PW-Doppler was poor
(r=− 0.09) in the subgroup with steatosis. A better
correlation (r=0.61) was observed in patients with liver cirrhosis.

Conclusion PFA and PW-Doppler assessment of portal venous vascularization
showed high agreement in healthy volunteers and patients with liver cirrhosis.
Therefore, PFA represents a possible alternative to conventional PW-Doppler
sonography for visceral blood flow diagnostics and merits further
evaluation.
„The Social Brain“ – Neurobiologie des
Sozialverhaltens
Authors: Fries Wolfgang
Published: March 2023

Die Spezies Homo sapiens zeichnet sich durch ein außerordentlich hohes
Maß an sozialer Interaktivität in allen Lebensphasen und
Alltagsaufgaben aus. Für alle Aktivitäten in der sozialen
Gemeinschaft und für die Teilhabe am sozialen und am beruflichen Leben
stellt die Fähigkeit zu einem geordneten Sozialverhalten eine notwendige
Grundlage dar.
Störungen der Gedächtnisfunktion
Authors: Markowitsch Hans J. , Staniloiu Angelica
Published: March 2023

Gedächtnis zu haben, stellt eine der zentralsten Funktionen des
menschlichen Gehirns dar und ermöglicht es uns, in der Gegenwart aus der
Vergangenheit für die Zukunft zu schöpfen. Wie wird
Gedächtnis unterteilt? Wie erfolgt die Gedächtnisverarbeitung
auf der Hirnebene? Welche Erkrankungen gehen mit Auswirkungen auf das
Gedächtnis einher?
Unilateraler Neglect nach Hirnschädigung
Authors: Karnath Hans-Otto , Schenk Thomas
Published: March 2023

Die Hauptfolge einer Schädigung der rechten Gehirnhälfte im
kognitiven Bereich ist das Auftreten eines Neglects, das heißt einer
Störung unserer Fähigkeit, den umgebenden Raum
vollständig zu explorieren und die Aufmerksamkeit auf für uns
relevante Dinge und Personen zu lenken, wenn diese links von uns positioniert
sind. Diese Störung nach rechtshemisphärischen
Schädigungen ist ähnlich häufig zu beobachten wie
Sprachstörungen nach Läsionen der anderen, der linken
Gehirnhälfte. Im Vergleich zu einer Aphasie sind die Symptome eines
Neglects für Patienten sowie Angehörige häufig weniger
offensichtlich. Für die Betroffenen sind die Folgen jedoch ebenso
weitreichend wie die einer Sprachstörung. Dies unterstreicht die
Notwendigkeit einer Untersuchung und Behandlung des Neglects bereits im
frühen Stadium nach einer Hirnläsion. Der Artikel gibt einen
Überblick über den aktuellen Stand zu Diagnostik und Therapie
des Neglects.
Prazosin Protects the Liver Against Renal
Ischemia/Reperfusion Injury in Rats
Authors: Khajepour Fatemeh , Mahmoodpoor Fariba , Jafari Elmira , Kakaei Farzad , Bahraminia Farina , Aghajani Shadi , Vahed Sepideh Zununi , Bagheri Yasin
Published: March 2023

Acute kidney injury (AKI) is a common subsequent problem after many medical
conditions. AKI is associated with distant organ dysfunction where systemic
inflammation and oxidative stress play major roles. In this study, the effect of
Prazosin, an α1-Adrenergic receptor antagonist, was investigated on the
liver injury induced by kidney ischemia-reperfusion (I/R) in rats. Male
adult Wistar rats (n=21) were divided into three groups: sham, kidney
I/R, and kidney I/R pre-treated with Prazosin
(1 mg/kg). Kidney I/R was induced by vascular clamping
of the left kidney for 45 min to reduce the blood flow. Oxidative and
antioxidant factors along with apoptotic (Bax, Bcl-2, caspase3), and
inflammatory (NF-κβ, IL-1β, and IL-6) factors were
measured in the liver at protein levels. Prazosin could reserve liver function
(p<0.01) and increase glutathione level (p<0.05) after kidney
I/R significantly. Malonil dialdehyde (MDA), a lipid peroxidation
marker, was diminished more significantly in Prazosin-treated rats compared to
the kidney I/R group (p<0.001). Inflammatory and apoptotic
factors were diminished by Prazosin pre-treatment in the liver tissue
(p<0.05). Pre-administration of Prazosin could preserve liver function
and decrease its inflammatory and apoptotic factors under kidney I/R
conditions.
Characterizing Osteochondral Allograft Biomechanics for Optimizing Transplant Success: A Systematic Review
Authors: Luk Josephine , Troyer Luke , Guess Trent M. , Teixeiro Emma , Stannard James P. , Cook James L.
Published: March 2023

Osteochondral allograft (OCA) transplantation has been largely successful in treating symptomatic articular cartilage lesions; however, treatment failures persist. While OCA biomechanics have been consistently cited as mechanisms of treatment failure, the relationships among mechanical and biological variables that contribute to success after OCA transplantation have yet to be fully characterized. The purpose of this systematic review was to synthesize the clinically relevant peer-reviewed evidence targeting the biomechanics of OCAs and the impact on graft integration and functional survival toward developing and implementing strategies for improving patient outcomes. The Cochrane Central Register of Controlled Trials, the Cochrane Database of Systematic Reviews, MEDLINE, PubMed, Cumulative Index to Nursing and Allied Health (CINAHL), Google Scholar, and EMBASE were searched to identify articles for systematic review. This review of relevant peer-reviewed literature provided evidence that the biomechanics related to OCA transplantation in the knee have direct and indirect effects on functional graft survival and patient outcomes. The evidence suggests that biomechanical variables can be optimized further to enhance benefits and mitigate detrimental effects. Each of these modifiable variables should be considered regarding indications, patient selection criteria, graft preservation methodology, graft preparation, transplantation, fixation techniques, and prescribed postoperative restriction and rehabilitation protocols. Criteria, methods, techniques, and protocols should target OCA quality (chondrocyte viability, extracellular matrix integrity, material properties), favorable patient and joint characteristics, rigid fixation with protected loading, and innovative ways to foster rapid and complete OCA cartilage and bone integration to optimize outcomes for OCA transplant patients.
Multi-mode analysis of surface losses in a superconducting microwave resonator in high magnetic fields
Authors: Braine T. , Rybka G. , Baker A. A. , Brodsky J. , Carosi G. , Du N. , Woollett N. , Knirck S. , Jones M. ,   ADMX Collaboration
Published: March 2023

This paper reports on a surface impedance measurement of a bulk metal niobium–titanium superconducting radio frequency (SRF) cavity in a magnetic field (up to 10 T). A novel method is employed to decompose the surface resistance contributions of the cylindrical cavity end caps and walls using measurements from multiple TM cavity modes. The results confirm that quality factor degradation of a NbTi SRF cavity in a high magnetic field is primarily from surfaces perpendicular to the field (the cavity end caps), while parallel surface resistances (the walls) remain relatively constant. This result is encouraging for applications needing high Q cavities in strong magnetic fields, such as the Axion Dark Matter eXperiment because it opens the possibility of hybrid SRF cavity construction to replace conventional copper cavities.
The asymmetric valence-bond-solid states in quantum spin chains: The difference between odd and even spins
Authors: Maekawa Daisuke , Tasaki Hal
Published: March 2023

The qualitative difference in low-energy properties of spin S quantum antiferromagnetic chains with integer S and half-odd-integer S discovered by Haldane [F. D. M. Haldane, arXiv:1612.00076 (1981); Phys. Lett. A 93, 464–468 (1983); Phys. Rev. Lett. 50, 1153–1156 (1983)] and Tasaki [Tasaki, Graduate Texts in Physics (Springer, 2020)] can be intuitively understood in terms of the valence-bond picture proposed by Affleck et al. [I. Affleck, Phys. Rev. Lett. 59, 799 (1987); Commun. Math. Phys. 115, 477–528 (1988)]. Here, we develop a similarly intuitive diagrammatic explanation of the qualitative difference between chains with odd S and even S, which is at the heart of the theory of symmetry-protected topological (SPT) phases. (There is a 24 min video in which the essence of the present work is discussed: https://youtu.be/URsf9e_PLlc.) More precisely, we define one-parameter families of states, which we call the asymmetric valence-bond solid (VBS) states, that continuously interpolate between the Affleck–Kennedy–Lieb–Tasaki (AKLT) state and the trivial zero state in quantum spin chains with S = 1 and 2. The asymmetric VBS state is obtained by systematically modifying the AKLT state. It always has exponentially decaying truncated correlation functions and is a unique gapped ground state of a short-ranged Hamiltonian. We also observe that the asymmetric VBS state possesses the time-reversal, the Z2×Z2, and the bond-centered inversion symmetries for S = 2 but not for S = 1. This is consistent with the known fact that the AKLT model belongs to the trivial SPT phase if S = 2 and to a nontrivial SPT phase if S = 1. Although such interpolating families of disordered states were already known, our construction is unified and is based on a simple physical picture. It also extends to spin chains with general integer S and provides us with an intuitive explanation of the essential difference between models with odd and even spins.
A thermoacoustic cooler with a bypass expansion for distributed-temperature heat loads
Authors: Hu Yiwei , Wang Xin , Wu Zhanghua , Zhang Limin , Chen Geng , Xu Jingyuan , Luo Ercang
Published: March 2023

In the context of the current energy crisis, a compact, simple, and reliable cooler is required at small-scale natural gas liquefaction stations. In this paper, a thermoacoustic cooler with a bypass expansion cooling for distributed-temperature heat loads is proposed. The bypass expansion configuration is used to carry out multiple refrigeration processes to achieve distributed cooling temperatures, thus realizing the cascade processes of natural gas liquefaction and improving the liquefaction efficiency. Simulations were carried out to investigate the effect of cooling-stage numbers on relative power consumption efficiency, exergy losses of components as well as axial distributions of key parameters. A proof-of-concept porotype of a two-stage thermoacoustic cooler was built, and the feasibility of the distributed heat loads was experimentally tested. Comparisons with a conventional single-stage thermoacoustic cooler without bypass expansion indicate that the proposed bypass expansion system improves the liquefaction cooling efficiency by a factor of 3.28 at 120 K. Experiments were also carried out to investigate the effect of the bypass expansion, an important factor, by verifying the total number of bypass orifices. Results show that increasing the number of bypass orifices with a more uniform gas distribution can improve the cooling performance of the system. The findings demonstrate the promising prospects of the proposed thermoacoustic cooler in the field of natural gas liquefaction.
A variable-speed-condition bearing fault diagnosis methodology with recurrence plot coding and MobileNet-v3 model
Authors: Gu Yingkui , Chen Ronghua , Wu Kuan , Huang Peng , Qiu Guangqi
Published: March 2023

To improve the quality of the non-stationary vibration features and the performance of the variable-speed-condition fault diagnosis, this paper proposed a bearing fault diagnosis approach with Recurrence Plot (RP) coding and a MobileNet-v3 model. 3500 RP images with seven fault modes were obtained with angular domain resampling technology and RP coding and were input into the MobileNet-v3 model for bearing fault diagnosis. Additionally, we performed a bearing vibration experiment to verify the effectiveness of the proposed method. The results show that the RP image coding method with 99.99% test accuracy is superior to the other three image coding methods such as Gramian Angular Difference Fields, Gramian Angular Summation Fields, and Markov Transition Fields with 96.88%, 90.20%, and 72.51%, indicating that the RP image coding method is more suitable for characterizing variable-speed fault features. Compared with four diagnosis methods such as MobileNet-v3 (small), MobileNet-v3 (large), ResNet-18, and DenseNet121, and two state-of-the-art approaches such as Symmetrized Dot Pattern and Deep Convolutional Neural Networks, RP and Convolutional Neural Networks, it is found that the proposed RP+MobileNet-v3 model has the best performance in all aspects with diagnosis accuracy, parameter numbers, and Graphics Processing Unit usage, overcoming the over-fitting phenomenon and increasing the anti-noise performance. It is concluded that the proposed RP+MobileNet-v3 model has a higher diagnostic accuracy with fewer parameters and is a lighter model.
An optoelectronic muscle contraction sensor for prosthetic hand application
Authors: Sharma Neeraj , Prakash Alok , Sharma Shiru
Published: March 2023

Surface electromyography (sEMG) is considered an established means for controlling prosthetic devices. sEMG suffers from serious issues such as electrical noise, motion artifact, complex acquisition circuitry, and high measuring costs because of which other techniques have gained attention. This work presents a new optoelectronic muscle (OM) sensor setup as an alternative to the EMG sensor for precise measurement of muscle activity. The sensor integrates a near-infrared light-emitting diode and phototransistor pair along with the suitable driver circuitry. The sensor measures skin surface displacement (that occurs during muscle contraction) by detecting backscattered infrared light from skeletal muscle tissue. With an appropriate signal processing scheme, the sensor was able to produce a 0–5 V output proportional to the muscular contraction. The developed sensor depicted decent static and dynamic features. In detecting muscle contractions from the forearm muscles of subjects, the sensor showed good similarity with the EMG sensor. In addition, the sensor displayed higher signal-to-noise ratio values and better signal stability than the EMG sensor. Furthermore, the OM sensor setup was utilized to control the rotation of the servomotor using an appropriate control scheme. Hence, the developed sensing system can measure muscle contraction information for controlling assistive devices.
Stability of laser cavity-solitons for metrological applications
Authors: Cutrona A. , Rowley M. , Bendahmane A. , Cecconi V. , Peters L. , Olivieri L. , Little B. E. , Chu S. T. , Stivala S. , Morandotti R. , Moss D. J. , Totero Gongora J. S. , Peccianti M. , Pasquazi A.
Published: March 2023

Laser cavity-solitons can appear in systems comprised of a nonlinear microcavity nested within an amplifying fiber loop. These states are robust and self-emergent and constitute an attractive class of solitons that are highly suitable for microcomb generation. Here, we present a detailed study of the free-running stability properties of the carrier frequency and repetition rate of single solitons, which are the most suitable states for developing robust ultrafast and high repetition rate comb sources. We achieve free-running fractional stability on both optical carrier and repetition rate (i.e., 48.9 GHz) frequencies on the order of 10−9 for a 1 s gate time. The repetition rate results compare well with the performance of state-of-the-art (externally driven) microcomb sources, and the carrier frequency stability is in the range of performance typical of modern free-running fiber lasers. Finally, we show that these quantities can be controlled by modulating the laser pump current and the cavity length, providing a path for active locking and long-term stabilization.
Polyethylenimine-based bifunctional interfacial layer for efficient quantum dot photovoltaics
Authors: Li Xiaofei , Wang Yinglin , Jia Yuwen , Wang Chao , Liu Xinlu , Liu Shuai , Zhang Xintong , Liu Yichun
Published: March 2023

Interface engineering, which efficiently optimizes the interfacial carrier collection and recombination, has been proven to be of importance for the emerging colloidal quantum dot solar cells (CQDSCs). Compared with the attractive modification efforts at the interface between quantum dots and the anode/electron transport layer (ETL), the interface between fluorine-doped tin-oxide (FTO) cathodes and the ETL, for which there exists a band alignment mismatch and high trap density in ZnO, has been investigated less. Herein, two kinds of ethylenimine-based polymers, branched by only ethylenimine groups (b-PEI) and by both ethylenimine/ethoxylated groups (e-PEI), respectively, are introduced as bifunctional interfacial layers (BILs) in lead sulfide (PbS) CQDSCs. PEI-based BILs were utilized to modulate the work function of an FTO cathode for optimizing the band alignment at the FTO/ZnO interface and to control the crystallinity of ZnO for reducing its traps. These BILs suppressed the interfacial carrier recombination and achieved a power conversion efficiency (PCE) of 11.28% in CQDSCs, which was much superior to the PCE of the reference device without BIL (10.29%). Also, the branched side chain of PEI-based BILs plays a crucial role in rationally modulating the Schottky barrier to gain different interface-optimization effects. Our work has laid a foundation for the commercial application of CQDSCs due to the advantage of low-temperature solution processability, low-cost, and scalable manufacturing.
Multi-angle in
situ dynamic light scattering at a neutron spin echo spectrometer
Authors: Vögl F. , Balacescu L. , Holderer O. , Pasini S. , Staringer S. , Brandl G. , Ossovyi V. , Feilbach H. , Müller-Buschbaum P. , Stadler A. M. , Fitter J. , Schrader T. E.
Published: March 2023

A new sample environment, called Bio-Oven, has been built for the Neutron Spin Echo (NSE) Spectrometer J-NSE Phoenix. It provides active temperature control and the possibility to perform Dynamic Light Scattering (DLS) measurements during the neutron measurement. DLS provides diffusion coefficients of the dissolved nanoparticles, and thus one can monitor the aggregation state of the sample on a time scale of minutes during the spin echo measurement times on the order of days. This approach helps to validate the NSE data or to replace the sample when its aggregation state influences the spin echo measurement results. The new Bio-Oven is an in situ DLS setup based on optical fibers decoupling the free space optics around the sample cuvette in a lightproof casing from the laser sources and the detectors. It collects light from three scattering angles simultaneously. Six different values of momentum transfer can be accessed by switching between two different laser colors. Test experiments were performed with silica nanoparticles with diameters ranging from 20 nm up to 300 nm. Their hydrodynamic radii were determined from DLS measurements and compared with the ones obtained by a commercial particle sizer. It was demonstrated that also the static light scattering signal can be processed and gives meaningful results. The protein sample apomyoglobin was used for a long-term test and in a first neutron measurement using the new Bio-Oven. The results prove that the aggregation state of the sample can be followed using in situ DLS along with the neutron measurement.
Two-qubit quantum photonic processor manufactured by femtosecond laser writing
Authors: Skryabin N. N. , Kondratyev I. V. , Dyakonov I. V. , Borzenkova O. V. , Kulik S. P. , Straupe S. S.
Published: March 2023

We present an experimental implementation of a two-qubit photonic quantum processor fabricated using femtosecond laser writing technology. We employ femtosecond laser writing to create a low-loss reconfigurable photonic chip, implementing precise single-qubit and two-qubit operations. We present a careful characterization of the performance of single- and two-qubit gates. An exemplary application of estimating the ground state energy of an H2 molecule using the variational quantum eigensolver algorithm is demonstrated. Our results highlight the potential of the femtosecond laser writing technology to deliver high quality small-scale quantum photonic processors.
Solution-processed high stability top-gate W and F co-doped ZnSnO thin film transistors
Authors: Hu Sunjie , Xu Meng , Peng Cong , Chen Longlong , Liu Hai , Li Xifeng
Published: March 2023

In this work, top-gate structured W: F co-doped Zn–Sn–O (ZTO) thin-film transistors (TFTs) with excellent stability are prepared by the solution process. Comparing with the undoped ZTO TFT, the mobility of W: F co-doped ZTO TFTs was up from 1.87 to 3.14 cm2 V−1 s−1, and the subthreshold swing decreases from 0.192 to 0.157 V/dec. Moreover, the W: F co-doped ZTO TFTs exhibit a small Vth shift of −0.09 V under negative bias illumination stress, which is close to one of the TFTs prepared by the traditional vacuum process. X-ray photoelectron spectroscopy and capacitance–voltage examination revealed that the enhanced stability is due to the fact that W: F co-doping can effectively suppress defect states in ZTO films. The results manifest that W: F co-doping may be a promising method for enhancing the stability of TFTs with the top-gate structure.
Scanning inverse spin Hall effect spectrometer by shorted coaxial probes
Authors: Luo Peiwen , Wu Zhe , Huang Fei , Peng Bin , Zhang Wenxu
Published: March 2023

In this work, a scanning inverse spin Hall effect measurement system based on a shorted coaxial resonator has been built, which provides a high throughput method to characterize spin transport properties. The system is capable of performing spin pumping measurements on patterned samples within an area of 100 × 100 mm2. Its capability was demonstrated with Py/Ta bilayer stripes deposited on the same substrate with different thicknesses of Ta. The results show that the spin diffusion length is about 4.2 nm with a conductivity of about 7.5 × 105 Ω−1 m−1, which leads to the conclusion that the intrinsic mechanism of spin relaxation of Ta is the Elliott–Yafet interactions. The spin Hall angle of Ta is estimated to be about −0.014 at room temperature. The setup developed in this work provides a convenient, efficient, and nondestructive way to obtain the spin and electron transportation characteristics of the spintronic materials, which will fertilize this community by developing new materials and figuring out their mechanism.
Impedance-matched high-overtone bulk acoustic resonator
Authors: Kurosu M. , Hatanaka D. , Ohta R. , Yamaguchi H. , Taniyasu Y. , Okamoto H.
Published: March 2023

We demonstrated a nearly impedance-matched high-overtone bulk acoustic resonator (HBAR) operating at super high frequency ranges using an epitaxial AlN piezoelectric layer directly grown on a conductive SiC cavity substrate with no metal layer insertion. The small impedance mismatch was verified from the variation in the free spectral range (FSR); the experimentally obtained FSR spectra were greatly reproduced using the Mason model. Broadband phonon cavity modes up to the K-band (26.5 GHz) were achieved at an AlN layer thickness of 200 nm. The high figure of merit of f×Q=1.3×1013 Hz at 10 GHz was also obtained. Our nearly impedance-matched high-quality HBAR will enable the development of microwave signal processing devices for 5G and future 6G communication systems, such as low-phase noise oscillators and acoustic filters, as well as research on high-frequency acoustic systems hybridized with electric, optical, and magnetic systems.
Electronic Born–Oppenheimer approximation in nuclear-electronic orbital dynamics
Authors: Li Tao E. , Hammes-Schiffer Sharon
Published: March 2023

Within the nuclear-electronic orbital (NEO) framework, the real-time NEO time-dependent density functional theory (RT-NEO-TDDFT) approach enables the simulation of coupled electronic-nuclear dynamics. In this approach, the electrons and quantum nuclei are propagated in time on the same footing. A relatively small time step is required to propagate the much faster electronic dynamics, thereby prohibiting the simulation of long-time nuclear quantum dynamics. Herein, the electronic Born–Oppenheimer (BO) approximation within the NEO framework is presented. In this approach, the electronic density is quenched to the ground state at each time step, and the real-time nuclear quantum dynamics is propagated on an instantaneous electronic ground state defined by both the classical nuclear geometry and the nonequilibrium quantum nuclear density. Because the electronic dynamics is no longer propagated, this approximation enables the use of an order-of-magnitude larger time step, thus greatly reducing the computational cost. Moreover, invoking the electronic BO approximation also fixes the unphysical asymmetric Rabi splitting observed in previous semiclassical RT-NEO-TDDFT simulations of vibrational polaritons even for small Rabi splitting, instead yielding a stable, symmetric Rabi splitting. For the intramolecular proton transfer in malonaldehyde, both RT-NEO-Ehrenfest dynamics and its BO counterpart can describe proton delocalization during the real-time nuclear quantum dynamics. Thus, the BO RT-NEO approach provides the foundation for a wide range of chemical and biological applications.
Neural-like population coding based on spin-torque diode
Authors: Tu Huayao , Zhang Like , Luo Yanxiang , Lv Wenxing , Lei Ting , Cai Jialin , Fang Bin , Finocchio Giovanni , Bian Lifeng , Li Shuping , Zhang Baoshun , Zeng Zhongming
Published: March 2023

Neuroscience studies have shown that population coding in biological systems can carry out resilient information processing with ensemble of neurons. Such strategy is valuable for the future development of electronics, particularly as the downscaling of transistors is reaching atomic limits and causing problems of large device-to-device variability and even device failure. In this work, we propose that nanoscale spin-torque diode (STD) based on a magnetic tunnel junction can be used to implement population coding. We also demonstrate that a basis set obtained from a single STD by time multiplexing can realize the generation of cursive letters. Furthermore, different activation functions of an artificial neural network have been acquired. In addition, high recognition rates of the Mix National Institute of Standards and Technology handwritten digits up to 94.88% are achieved using an output function constructed from the experimental data. Our work may provide inspiration for designing neuromorphic computing systems.
Enhanced photoresponse of a dielectric-free suspended WSe2–ReS2 heterostructure photodetector
Authors: Jawa Himani , Khandare Nitish , Varghese Abin , Sahoo Srilagna , Lodha Saurabh
Published: March 2023

Optoelectronic devices based on layered two-dimensional (2D) van der Waals (vdW) semiconductors and their heterostructures suffer from carrier scattering, trapping, and trap-assisted recombination-generation at the vdW channel/dielectric interface. In this work, we demonstrate improved photoresponse of a dielectric-free, suspended WSe2 (p)-ReS2 (n) heterostructure photodetector in comparison to an hBN dielectric-supported structure fabricated over a common local Au back gate. The dielectric-free suspension helps in eliminating optical losses at the 2D channel–dielectric interface and optical absorption loss in the dielectric itself as the metal (gold) gate aids in reflecting the incident light to enhance absorption in the 2D heterostructure. The increase in photocurrent increases with incident illumination power and is consistent over a wide range of wavelengths. Suspension of 2D layered materials, thus, paves the route for harnessing their intrinsic properties for next generation photodetection applications.
Vaccination games and imitation dynamics with memory
Authors: Kyrychko Y. N. , Blyuss K. B.
Published: March 2023

In this paper, we model dynamics of pediatric vaccination as an imitation game, in which the rate of switching of vaccination strategies is proportional to perceived payoff gain that consists of the difference between perceived risk of infection and perceived risk of vaccine side effects. To account for the fact that vaccine side effects may affect people’s perceptions of vaccine safety for some period of time, we use a delay distribution to represent how memory of past side effects influences current perception of risk. We find disease-free, pure vaccinator, and endemic equilibria and obtain conditions for their stability in terms of system parameters and characteristics of a delay distribution. Numerical bifurcation analysis illustrates how stability of the endemic steady state varies with the imitation rate and the mean time delay, and this shows that it is not just the mean duration of memory of past side effects, but also the actual distribution that determines whether disease will be maintained in the population at some steady level, or if sustained periodic oscillations around this steady state will be observed. Numerical simulations illustrate a comparison of the dynamics for different mean delays and different distributions, and they show that even when periodic solutions are observed, there are differences in their amplitude and period for different distributions. We also investigate the effect of constant public health information campaigns on vaccination dynamics. The analysis suggests that the introduction of such campaigns acts as a stabilizing factor for endemic equilibrium, allowing it to remain stable for larger values of mean time delays.
High efficiency mid-infrared interband cascade light emitting diodes with immersion lens
Authors: Chai X. L. , Zhou Y. , Zhang W. L. , Zhu Y. H. , Liang Z. M. , Xu Z. C. , Chen J. X.
Published: March 2023

We report on ten-stage interband cascade light-emitting diodes (ICLEDs) using an InAs/GaAsSb superlattices active region with a peak emission wavelength of 4.9 μm at the temperature of 80 K. The ICLED devices integrated with an immersion lens achieve a wall-plug quantum efficiency of 6.6% and an emittance of 1.9 W/cm2 under 80 K and 7.7 A/cm2, which is seven times larger than the basic device without the immersion lens. We present a detailed analysis of the recombination rates and their relationship with the quantum efficiency. The Shockley–Read–Hall and Auger recombination rates were measured using carrier-density dependent time-resolved photoluminescence spectra. The band structure of InAs/GaAsSb superlattices is calculated to study their relationship with the Auger recombination rates.
Doping effects on the ferroelectric properties of wurtzite nitrides
Authors: Liu Zhijie , Wang Xinyu , Ma Xingyue , Yang Yurong , Wu Di
Published: March 2023

Ferroelectric materials have been explored for a long time for easy integration with state-of-the-art semiconductor technologies. Doped wurtzite nitrides have been reported as promising candidates due to their high stability, compatibility, and scalability. We investigate doping effects on ferroelectric properties of Sc-doped AlN (AlScN) and B-doped AlN (AlBN) by first-principles methods. The energy barrier against polarization switching is observed to decrease with increasing doping concentration at low concentration ranges, which is the origin of the emerging ferroelectricity in doped AlN. Further increasing the doping concentration to a critical value, the ferroelectric wurtzite phase transforms into paraelectric phases (a rock salt phase for AlScN and a zinc blende phase for AlBN), making it invalid to decrease the coercivity by increasing the doping concentration. Furthermore, it is revealed that different nonpolar structures (a hexagonal phase for AlScN and a β-BeO phase for AlBN) appear in the ferroelectric switching pathway, generating different switching features in doped AlN. Our results give a microscopic understanding of the ferroelectricity in doped wurtzite materials and broaden the route to improve their ferroelectric properties.
Flexible self-powered DUV photodetectors with high responsivity utilizing Ga2O3/NiO heterostructure on buffered Hastelloy substrates
Authors: Tang Xiao , Lu Yi , Lin Rongyu , Liao Che-Hao , Zhao Yue , Li Kuang-Hui , Xiao Na , Cao Haicheng , Babatain Wedyan , Li Xiaohang
Published: March 2023

In this research, β-Ga2O3/NiO heterostructures were grown directly on CeO2 buffered Hastelloy flexible substrates. With pulsed laser deposition under high temperatures, as-grown β-Ga2O3 and NiO thin films have a preferred out-of-plane orientation along the ⟨−201⟩ and ➎111➉ directions. This is due to the ideal epitaxial ability of the CeO2 buffer layer, which serves as a perfect template for the epitaxial growth of single-oriented NiO and β-Ga2O3 by creating a constant gradient from CeO2 (2.7 Å along ➎001➉) to NiO (2.9 Å along ➎110➉), and eventually to β-Ga2O3 (3.04 Å along ➎010➉). The Hastelloy substrates endow photodetectors with good deformability and mechanical robustness. Moreover, owing to the type-II band alignment of β-Ga2O3/NiO heterostructures, the photodetectors have a good photocurrent at zero bias under 284 nm of light illumination. In addition, the photocurrent is significantly higher than when using an analogous heterostructure (as described in some previous reports), because the β-Ga2O3 and NiO thin films are crystalized along a single orientation with fewer defects.
Dynamics of cell wall components and histochemical profile of a rust fungi gall (Basidiomycota: Pucciniales) on Byrsonima variabilis A.Juss. (Malpighiaceae)
Authors: Migliorini Mendes Reisila S. , Costa Elaine C. , Oliveira Lucas C. , Gomes Flávia M. , Oliveira Denis C. , Isaias Rosy M. S.
Published: March 2023

Context An obligate biotrophic parasitism with a rust fungus led to gall formation on Byrsonima variabilis. Aims The hypothesis that the host leaf–rust fungi interaction alters the dynamics of plant cell walls and the histochemical profile toward favouring the plant cell-to-fungi cell translocation of metabolites is tested. Methods Gall samples were sectioned and submitted to anatomical, histometric, histochemical, and immunocytochemical techniques to evaluate structural alterations and the detection of primary and secondary metabolites, as well as the epitopes of glycoproteins, pectins, and hemicelluloses. Key results Fungi gall development results in the hypertrophy of the stomatal chamber and the hyperplasia of epidermis and spongy parenchyma. The cell-to-cell translocation of metabolites from plant mesophyll cells toward the rust fungi gall is favoured by the epitopes of homogalacturonans (HGs) and (1 → 5) α-l-arabinans detected in the hyphae passage sites in the pycnial and aecial stages. The arabinogalactan-proteins (AGPs) may favour mycelial nutrition and differentiation, and cell wall adhesion. HGs and arabinans confer porosity to mesophyll cell walls, which favours the traffic of molecules toward the rust fungi gall. Conclusions The unexpected labelling of AGPs, HGs, and arabinans in fungi cell walls is a novelty regarding the plant–fungi interaction. The primary metabolites detected in rust fungi support hyphae growth and spore maturation. Implications The immunolabelling of host plant cell wall components on fungi cell walls indicates the integrative role of some plant cell wall components in the biological process of pathogen colonisation in leaf tissues.