bluuebunny/crossref_metadata_2025 huggingface dataset:
Reversible photomechanical actuators with liquid crystal polymer graphene oxide nanocomposites
Authors: Li Guan-Ting , Hsu Chia-Hsien , Singh Bhupendra Pratap , Hwang Shug-June
Published: November 2024

This study quantifies the photomechanical actuation in LC242 nanocomposites doped with azo dye and graphene oxide. Optimized doping and UV curing achieve a 35° photo-induced bend with rapid response, advancing applications in smart materials.
External field-engineered tunable chern number and valley-polarized quantum anomalous hall effect in Ti3S3Te2 monolayer
Authors: Xu Xiaokang , Lu Jinlian , Lian Huijie , Han Ying , Liu Yongjun , Yu Xueke , He Ailei , Yao Xiaojing , Zhang Xiuyun
Published: November 2024

Quantum anomalous Hall (QAH) insulators with tunable Chern numbers have excellent application prospects in spintronics.
A SET‐tolerant StrongARM comparator with improved performance
Authors: Zhou Chentian , Han Yuanyuan , Cheng Xu , Zeng Xiaoyang
Published: November 2024

In this paper, a radiation hardened by design StrongARM comparator is proposed to mitigate the radiation effects. With 12 additional transistors compared to the conventional one, the proposed structure shows much higher immunity to single‐event transients. During the amplification phase, when the input differential voltage is 10 mV, the proposed structure can withstand up to 18fC free charge, 45x far surpassing the conventional structure. During the regeneration phase, every sensitive node in the proposed structure can withstand a 200 fC‐injected charge. Compared to other redundant structures with performance deterioration, the proposed architecture exhibits high‐speed characteristics. When the differential voltage between two inputs is 1 mV, the delay of the new structure is 168.26 ps and the speed improvement is 118.02% over the conventional structure.
Revisiting the role of thermal energy storage in low‐temperature electrified district heating systems
Authors: Lu Hai , Zhang Hao , Lu Shuai
Published: November 2024

Decarbonising the energy supply system is crucial to mitigate climate challenges. An emerging type of the multi‐energy system, that is, the low‐temperature electrified district heating system is gaining increasing popularity as a potential solution for future low‐carbon heat supply. This paper investigated its operational optimisation with thermal energy storage (TES) installed at building sides. The optimisation model was to obtain the minimum operation costs of all heat pumps in this system. The TES was meant to achieve energy arbitrage through load shift, but it was observed from the optimised results that the TES did not play an active role in the optimisation. Five possible causes were identified and further investigated to reveal their impacts on the optimisation process. Results showed that the thermal capacitance, thermal resistance, and indoor temperature range of the building were major influencing factors, while the electricity price tariff and heat loss parameters of TES were minor ones. The results indicate that there is no need to equip the TES for operational optimisation purposes when the building thermal capacitance is larger than a threshold value, the thermal resistance is smaller than a threshold value, or the indoor temperature range is broader than a threshold value. These threshold values are case‐specific and can be determined with the simulation model and method developed in this paper.
Investigation of lunar ejecta dynamics: particles reaching the near-Earth space and their effect on Earth-based observation
Authors: Yang Kun , Jiang Yu , Liang Youpeng , Liu Xiaodong
Published: November 2024

Aims. Particles ejected from the lunar surface via hypervelocity impacts form a torus between the Earth and the Moon. According to our previous study, about 2.3 × 10−4 kg/s particles impact the Earth after long-term orbital evolution. We mainly focus on these Earth impactors, analyze their orbital element distribution, and estimate their influence on Earth-based observations.

Methods. In previous work we simulated the long-term orbital evolution of particles ejected from the lunar surface, and obtained their steady-state spatial distribution in the Earth–Moon system. For this work we analyzed the simulation results for the Earth impactors, including the fraction of impactors with different initial parameters among all impactors, the orbital element distribution, and the projection of particles onto several Earth-based observatories.

Results. Particles ejected from the lunar surface are more likely to impact the Earth within a certain range of initial parameters. Most of these lunar-ejected impactors (~70%) reach the Earth within one year, while most of the small ones (87.2% of 0.2 μm particles and 64.6% of 0.5 μm particles) reach the Earth within one week. A large proportion of lunar-ejected Earth impactors can be distinguished from interplanetary dust particles according to the differences in their orbital distributions. In addition, lunar-ejected particles may exhibit distinct configurations and orientations from the perspectives of different Earth-based observatories.
The evolution of low-mass central galaxies in the vicinity of massive structures and its impact on the two-halo conformity
Authors: Palma Daniela , Lacerna Ivan , Celeste Artale M. , Montero-Dorta Antonio D. , Ruiz Andrés N. , Cora Sofía A. , Rodriguez Facundo , Pallero Diego , O’Mill Ana , Choque-Challapa Nelvy
Published: November 2024

We investigated the population of low-mass central galaxies with M⋆ = 109.5 − 1010 h−1 M⊙, inhabiting regions near massive groups and clusters of galaxies using the IllustrisTNG300 and MDPL2-SAG simulations. We set out to study their evolutionary histories, aiming to find hints about the large-scale conformity signal they produce. We also used a control sample of central galaxies with the same stellar mass range located far away from massive structures. For both samples, we find a subpopulation of galaxies accreted by another halo in the past, but now considered central galaxies; we refer to these objects as former satellites. The number of former satellites is higher for quenched central galaxies near massive systems, with fractions of 45% and 17% in IllustrisTNG300 and MDPL2-SAG, respectively. The differences in the numerical resolution of each simulation lead to the different fractions of former satellites. Our results in TNG300 show that former satellites “pollute” the sample of central galaxies because they suffered environmental processes when they were satellites hosted typically by massive dark matter halos (M200 ≥ 1013 h−1 M⊙) since z ≲ 0.5. After removing former satellites, the evolutionary trends for quenched central galaxies near massive structures are fairly similar to those of the quenched control galaxies, showing small differences at low redshift. For MDPL2-SAG instead, former satellites were hosted by less massive halos, with a mean halo mass around 1011.4 h−1 M⊙, and the evolutionary trends remain equal before and after removing former satellite galaxies. We also measured the two-halo conformity, that is, the correlation in the specific star formation rate between low-mass central galaxies and their neighbors at megaparsec scales, and how former satellites contribute to the signal at three different redshifts: z = 0, 0.3, and 1. The time evolution of the conformity signal in the simulations presents apparent contradictory results: it decreases from z = 0 to z = 1 in MDPL2-SAG, while it increases in TNG300. However, after removing former satellites in the latter, the signal is strongly reduced, but practically does not change at z ≤ 0.3, and it disappears at z = 1. We compare our findings with recent literature data and discuss the conformity measurements, as different approaches can lead to varying results.
Assistance from a mixing zone model to perform aortic femoral perfusion strategy with severe atherosclerotic and artheromic aortic disease for endoscopic minimally invasive redo mitral valve repair
Authors: Takeichi Tomohisa , Morimoto Yoshihisa , Yamada Akitoshi , Tanaka Takanori , Fujiwara Kunihiro , Sato Masanobu , Toma Ryo , Mitsui Kiyoto , Sugita Takumi , Yamada Hiroki , Nakagaki Kanako , Kuriyama Hiroto , Gan Kunio
Published: November 2024

Minimally invasive cardiac surgery (MICS) for redo mitral valve surgery in the presence of severe atheroma and atherosclerotic diseased atherosclerotic and artheromic aorta presents significant challenges and increases the risk of postoperative cerebral infarction. At our institution, to mitigate the risk of postoperative cerebral complications, we employ a strategy combining antegrade and retrograde perfusion during MICS for patients with atherosclerotic and artheromic aorta. However, the mixing zone during cardiopulmonary bypass (CPB) with combined antegrade and retrograde perfusion has not been thoroughly evaluated.In this case, we performed a completely endoscopic MICS redo mitral valve plasty (MVP). CPB was established using cannulation of both the ascending aorta (Asc Ao) and the femoral artery (FA). The patient received planned systemic hyperkalemia without an aortic cross clamp. In addition, due to aortic insufficiency, circulatory arrest was also needed. The patient experienced an uneventful post-operative recovery without any cerebral complication.Furthermore, we evaluated the mixing zone during the combined antegrade and retrograde perfusion using an arteriovenous circulation model. Our findings suggest that when performing perfusion via the Asc Ao and FA, it is advisable to select Asc Ao cannulation size reduced by one size against FA cannulation size to optimize the procedure.
High-concentration continuous local antibacterial perfusion therapy: safety and potential efficacy for acute and chronic periprosthetic knee joint infection
Authors: Suzuki Yuki , Iwasaki Koji , Joutoku Zenta , Onodera Tomohiro , Matsuoka Masatake , Hishimura Ryosuke , Hamasaki Masanari , Kondo Eiji , Iwasaki Norimasa
Published: November 2024

Background: Periprosthetic joint infections (PJIs) following total knee arthroplasty (TKA) are among the most challenging pathologies to manage. Recently, continuous local antibiotic perfusion (CLAP) therapy has been introduced for treating musculoskeletal infections in orthopedics. This study aimed to determine the outcomes and risks of CLAP therapy combined with conventional treatment for PJIs after TKA. Methods: We retrospectively evaluated 14 patients with PJIs. For acute PJIs, CLAP therapy was performed alongside debridement, intravenous antibiotics, and implant retention. For chronic PJIs, a two-stage revision with CLAP therapy and intravenous antibiotics was performed. Implants were replaced with a cement mold incorporating CLAP therapy, followed by revision surgery after 3 months. For all patients, 120 mg/day of gentamicin (GM) was locally administered into the knee joint for 2 weeks as part of CLAP therapy, in combination with perioperative intravenous antibiotics. Results: Five patients developed acute PJIs, and nine developed chronic PJIs after TKA. The mean follow-up period was 18.4 (15.2–21.1) months. All five patients with PJIs treated with one-stage surgery (debridement and insert exchange only) successfully preserved their implants. Among the nine patients with chronic PJIs, seven underwent CLAP therapy combined with two-stage revision surgery, resulting in successful treatment without relapse, whereas the remaining two patients were initially treated with one-stage surgery and CLAP therapy but failed to retain their implants, and subsequently required additional two-stage revision surgery, which ultimately succeeded. No adverse effects from GM were reported. Conclusions: Our results suggest that CLAP therapy is safe and may be effective for treating acute and most chronic PJIs after TKA.
Cardiac Troponin-I Level at 24 hours of Age in Stable Newborn Infants Born at ≥35 Weeks of Gestation
Authors: Rosario David C. , Pezzano Chad , Ward Lesa , Cerone Jennifer , Randall Jess , Munshi Upender K.
Published: November 2024

Objective Cardiac troponin-I is a known biomarker of myocardial injury in adults and children but its diagnostic utility is unclear in newborns.

This study aimed to establish normative data for troponin-I in stable newborns and assess any variation due to maternal diabetes status, mode of delivery, and Apgar scores.

Study Design Prospective, observational study of stable newborn ≥35 weeks gestation admitted to a well-baby nursery at a single institution. Infants with respiratory distress, congenital infections, malformations, or syndromes were excluded. Troponin-I values were obtained by a validated point-of-care capillary blood sample at 24 hours of age.

Results A total of 132 patients were included for analysis. Thirteen infants were born to mothers with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) during pregnancy and analyzed as a subgroup, with the remaining 119 infants comprising the base cohort to establish baseline normative troponin-I levels in stable newborn infants. The mean (standard deviation) troponin-I level of infants in the base cohort group was 0.019 ± 0.018 ng/mL and in infants born with maternal SARS-CoV-2 infection during pregnancy troponin-I level was 0.081 ± 0.1 ng/mL (p < 0.001). In infants of the base cohort, there was no significant difference in troponin-I levels between diabetic versus nondiabetic mothers, vaginal birth versus cesarean section, and 5-minute Apgar score of <7 versus ≥7.

Conclusion Cardiac troponin-I level in healthy term newborns was 0.019 ± 0.018 ng/mL, which conforms to healthy children and adult lab values. There was no statistically significant difference in troponin-I levels in infants of maternal diabetes or normal glucose status, mode of delivery, cesarean versus vaginal, or 5-minute Apgar score of <7 or ≥7. Troponin-I levels in asymptomatic neonates born to mothers with a history of SARS-CoV-2 during pregnancy demonstrated an elevation when compared to the baseline group of infants.

Key Points
In-Hospital Outcomes of Neonates with Hypoxic–Ischemic Encephalopathy Receiving Sedation–Analgesia during Therapeutic Hypothermia
Authors: Pease Mary E. , Yi Erica , Joshi Swosti , Poletto Erica , Menkiti Ogechukwu , Quiñones Cardona Vilmaris
Published: November 2024

Objective This study aimed to compare magnetic resonance imaging (MRI) severity scores and in-hospital outcomes among neonates with perinatal hypoxic–ischemic encephalopathy (HIE) with and without exposure to sedation–analgesia (SA) during therapeutic hypothermia (TH).

Study Design A single-center, retrospective cohort study of neonates with perinatal HIE undergoing TH between January 2010 and December 2020. Demographics, clinical characteristics, MRI scores, and in-hospital outcomes were compared between patients without SA exposure and those with SA use.

Results Of the 131 neonates, 55 (42%) did not have SA exposure, and 76 (58%) had SA during TH. Groups were similar in birth weight, gestational age, and severity of HIE. A higher proportion of neonates in the SA group received inhaled nitric oxide (iNO, 39.4% vs. 2%, p < 0.001) and vasopressors (41% vs. 20%, p = 0.012) compared to no SA group. There was no difference in median MRI severity scores for neither T1 (2 [2, 4.25] vs. 3 [2, 6], p = 0.295), T2 (2 [0, 3] vs. 3 [1.5, 5.5], p = 0.088) nor diffusion-weighted images (0 [0, 2] vs. 0 [0, 4.25], p = 0.090) between SA and no SA groups, respectively. In-hospital outcomes were similar between groups except for lower survival to discharge (87% vs. 98%, p = 0.020) in the SA group compared to those without SA. A regression analysis showed death was associated with the concomitant use of iNO (p < 0.001) and inotropes (p < 0.001).

Conclusion SA during TH for perinatal HIE did not alter early MRI severity scores. A lower survival to discharge in the SA group may be related to illness severity rather than SA use alone.

Key Points
Dabigatran Attenuates the Binding of Thrombin to Platelets—A Novel Mechanism of Action
Authors: Lindahl Tomas L. , Kumar Aishwarya Prasanna , Hallström Teresia , Al-Hashimi Ahmed , du Rietz Anna , Arlaman Elena , Uvdal Kajsa , Macwan Ankit S.
Published: November 2024

Background Thrombin is a multifunctional regulatory enzyme of the haemostasis and has both pro- and anticoagulant roles. It has, therefore, been a main target for drug discovery over many decades. Thrombin is a serine protease and possesses two positively charged regions called exosites, through which it is known to bind to many substrates. Dabigatran is a thrombin inhibitor and is widely used as an oral anticoagulant for the antithrombotic treatment of atrial fibrillation and venous thromboembolism. The mechanism by which dabigatran inhibits thrombin is the blockage of the active site, however, its effect on thrombin binding to its substrates has not been studied thoroughly and is thus poorly understood.

Material and Methods The effect of dabigatran on thrombin binding to platelets was evaluated by flow cytometry using fluorescently labelled thrombin and washed platelets. Further, to confirm the results we utilized modern techniques for biomolecular binding studies, microscale thermophoresis (MST) and surface plasmon resonance (SPR), which validated the results.

Results Dabigatran inhibited thrombin binding to platelets as analysed by flow cytometry. The inhibition was dose dependent with IC50 of 118 nM which was slightly lower than for inhibition of platelet activation and is close to the clinically relevant plasma concentration of dabigatran. MST and SPR also confirmed inhibitory effect of dabigatran on thrombin binding to platelets.

Conclusion Apart from blocking the active site, dabigatran also inhibits thrombin binding to platelets. Since thrombin has numerous functions beyond the cardiovascular system, this finding may have important implications.
The Impact of Perioperative Blood Transfusion on Flap Survival: A Single-Center Review of Limb Salvage in the Trauma Setting
Authors: O'Brien Devon , Pekcan Asli , Stanton Eloise , Roohani Idean , Zachary Paige , Parikh Neil , Daar David A. , Carey Joseph N.
Published: November 2024

Background Limb salvage following traumatic lower extremity (LE) injury often necessitates blood transfusion for adequate tissue perfusion. Appropriate transfusion decision-making via a risk–benefit analysis could maximize the opportunity for flap survival. This study aims to examine the impact of perioperative blood transfusion on postoperative complications in traumatic LE reconstruction.

Methods A retrospective review was conducted at a level 1 trauma center on patients who underwent LE reconstruction between January 2007 and October 2023. Patient demographics, comorbidities, perioperative blood transfusions, flap characteristics, and postoperative complications were recorded. Outcomes investigated included postoperative amputation rates, infection, partial flap necrosis, and flap loss. Univariate analysis and multivariable logistic regression were performed to examine the impact of patient factors on flap necrosis.

Results In total, 234 flaps met inclusion criteria. Of these, 149 cases (63.7%) received no transfusion during their hospital stay (Tf − ) and 85 cases (36.3%) received at least one unit of packed red blood cells intraoperatively through 48 hours following flap placement (Tf + ). Overall flap survival rates were similar across both cohorts (Tf + : 92.9 vs. Tf − : 96.6%, p = 0.198). The Tf+ cohort had significantly higher rates of partial flap necrosis (12.9 vs. 2.0.%, p < 0.001), amputation (6.0 vs. 0.7%, p = 0.015), and postoperative hardware infection (10.6 vs. 2.7%, p = 0.011) relative to the Tf− cohort. Multivariable logistic regression demonstrated that transfusion status was independently associated with a 5.1 fold increased risk of flap necrosis (p = 0.033).

Conclusion Transfusions administered intraoperatively through the acute postoperative period were associated with a significantly increased likelihood of flap necrosis. Surgeons should consider a conservative transfusion protocol to optimize flap viability in patients with traumatic LE injuries.
Microsurgeon Development, Attrition, and Hope for the Future: A Qualitative Analysis
Authors: Mauch Jaclyn T. , Byrnes Yasmeen M. , Kotian Alesha A. , Catzen Hannah Z. , Byrnes Mary E. , Myers Paige L.
Published: November 2024

Background The field of microsurgery continues to grow, yet barriers to practice still exist. This qualitative study aims to elucidate factors both strengthening and threatening this subspecialty through structured interviews with fellowship-trained microsurgeons.

Methods An interview guide was designed, and structured interviews were conducted with practicing fellowship-trained microsurgeon members of the American Society of Reconstructive Microsurgeons between August 2021 and May 2022. Three independent reviewers transcribed, content-coded, and thematically analyzed the interviews. Themes and subthemes were discussed and finalized.

Results Twenty-one practicing microsurgeons were interviewed, hailing from all four Census geographical regions of the United States. The most common practice model was academic (43%, n = 9). Five overarching themes emerged: a passion for microsurgery, training and mentorship, practical considerations, team support, and hope for the future. Microsurgeons reported early exposure to microsurgery as catalyzing their passion, whereas a strong training foundation and lifelong mentors sustained it. Practical challenges arose when establishing and maintaining a microsurgery practice, such as poor reimbursement and unfavorable referral patterns. Team support from staff and other microsurgeons (e.g., a co-surgeon model) was crucial to success. Finally, microsurgeons hoped that future advances would expand access to microsurgical reconstruction for patients and plastic surgeons.

Conclusion This unique, qualitative description of the current landscape of microsurgery revealed that though practical barriers exist, team-based models can alleviate some difficulties. Future advances that increase accessibility may further strengthen this unique and versatile field.
Risk Factors for Hearing Screen Failure in a Single-Family Room Neonatal Intensive Care Unit
Authors: Suflas Rebecca , Cox Rebecca , Viscardi Rose M. , Leung Jocelyn C.
Published: November 2024

Objective This study aimed to determine hearing screen outcomes and identify clinical and environmental risk factors for hearing screen failure in very preterm infants at a level IV single-family room (SFR) neonatal intensive care unit (NICU).

Study Design We conducted a retrospective study of infants <33 weeks gestational age admitted to a level IV SFR NICU who survived to discharge and had automated auditory brainstem response results available. Demographics, antenatal and postnatal factors, and respiratory support modes and their duration were collected from the electronic medical record.

Results Of 425 eligible infants with documented hearing screen results, 353 (83%) passed and 72 (17%) failed the hearing screen (unilateral, N = 44 [61%]; bilateral, N = 28 [39%]). Compared to infants who passed the hearing screen, infants with hearing screen failure were lower gestational age and birth weight, male sex, were screened at later postnatal and postmenstrual ages (PMAs), had lower 1- and 5-minute Apgar scores, longer duration of furosemide therapy, early hypotension, intraventricular hemorrhage (IVH) ≥Grade 3, and bronchopulmonary dysplasia (BPD) at 36 weeks PMA. Infants with hearing screen failure experienced longer exposures to invasive and noninvasive respiratory support. Heated, humidified, high flow nasal cannula >2 liters per minute exposure was significantly longer in infants with bilateral hearing screen failure (18.4 ± 18.4 d) compared to duration in infants who passed (7.4 ± 12.8 d) and those with unilateral failure (9 ± 13 d), (mean ± standard deviation [SD], p < 0.001). In the final logistic model, IVH ≥Grade 3 (odds ratio [OR] = 3.22, 95% confidence interval [CI]: 1.15–8.98, p = 0.026) and BPD (OR = 2.27, 95% CI: 1.25–4.11, p = 0.007) were the factors with the greatest risk for hearing screen failure.

Conclusion We speculate that the association of BPD with hearing screen failure may be mediated, in part, by chronic noise exposure, including from respiratory support devices. Attention to hearing protection in at-risk infants during respiratory support may mitigate the risk of hearing loss.

Key Points
Chemotherapy-Induced Fingerprint Effacement Leading to Deprivation of Health Insurance: A Case Series and Review of Literature
Authors: Bansal Shashank , Agrawal Deepika , Mishra Hemendra , Kharbandha Mahima , Patidar Rajesh , Chitalkar P.G.
Published: November 2024

Ayushman Bharat Pradhan Mantri Jan Arogya Yojana (PMJAY) is a game changer for the Indian health care system, where patients with cancer are the major beneficiaries. Some intrinsic procedural shortcomings are restricting the beneficiaries to utilize it optimally. We report a case series of patients receiving chemotherapy who had developed adermatoglyphia because of chemotherapeutic treatment. Therefore, these patients became ineligible for getting the benefits of PMJAY, because of failure of the biometric system to recognize their fingerprints. Hence, patient treatment could not be completed. As a solution, we suggest that the alternatives to fingerprint recognition like face recognition and iris scanning be incorporated into the biometric system to ensure continuous benefit of PMJAY to such patients.
The impact of climate risk on bank profitability through liquidity creation channel: empirical evidence from G7 countries
Authors: Lee Seungho , Alam Md Zahangir
Published: November 2024

This study investigates the impact of climate change-induced risk on bank profitability in the G7 countries from 2001 to 2022. Using dynamic panel GMM estimation to analyse banking industry data with climate risk factors, we find that climate risk has a negative effect on bank profitability. The study also demonstrates that bank liquidity creation plays a key role in transmitting the adverse impact of climate risk on bank profitability. Additionally, the results of the study are robust and withstand different measures of bank liquidity creation. Furthermore, our empirical findings indicate that the influence of climate risk factors is consistent, even for banks primarily focussed on the insurance business. These findings suggest that policymakers may need to implement climate risk management policies to mitigate the detrimental effects of climate change on the banking sector.
Magneto-optic resonance in Gd-La alloys
Authors: Gnezdilov V. P. , Nikol’skii G. S. , Eremenko V. V. , Beznosov A. B.
Published: November 2024

The optical spectra of several Gd–La alloys are examined. Within the infrared range there appears an absorption band associated with a transition to the magnetically ordered state. With the energy in this band known, it is possible to evaluate the exchange integral Id-f directly.
The magnetoresistivity of films with arbitrary angular dependence of the specular reflectivity
Authors: Pavlov S. D. , Popov V. I.
Published: November 2024

General equations are obtained for the magnetoconductance of a conducting film for an arbitrary angular dependence of the spectral reflectivity q(Φ). The relaxation-time approximation is used, which is justified for extremely thin films. Three magnetic-field orientations with respect to the film surface and the direction of the electric field are examined. Asymptotic equations are obtained for weak magnetic fields and the possibility is indicated of determining the angular dependence q(Φ) from resistivity measurements in the region of weak magnetic fields.
An exactly solvable model of the spin–lattice interaction
Authors: Glazman L. I.
Published: November 2024

We consider a model with a highly anisotropic spin–lattice interaction where the external magnetic field is directed along the anisotropy axis. An exact solution is obtained for the quantum problem of time evolution of a spin of arbitrary magnitude. We study the motion of a spin “deviating” originally from the equilibrium position, and find the absorption spectrum of a circularly polarized wave using an approximation linear in its amplitude. The possibility of a temperature-driven phase transition is indicated on the example of a cubic crystal with a magnetic sublattice and a specific form of the spin–phonon interaction.
Vibrational spectrum of a semi-infinite layered crystal
Authors: Syrkin E. S. , Gel’fgat I. M.
Published: November 2024

A simple method is used to investigate localized and surface vibrational states (both low-frequency and “gap” states) of a layered crystal with the plane wave-vector varying up to the two-dimensional Brillouin zone boundary.
Relaxation of impurities in a nonresonant field and phonon amplification
Authors: Dykman M. I.
Published: November 2024

It is shown that the distribution of weakly coupled impurities over the energy levels in a relatively weak field is altered substantially if the field frequency is in one of the absorption sidebands. Depending on the relationship between the impurity, field, and phonon frequencies, the impurity can be cooled or heated strongly, and the level population can also be inverted. If the field frequency is greater than the impurity frequency, then phonon magnification occurs at the difference frequency in a definite field range. Analogously, by inducing a decay into magnons by a longitudinal or transverse field, the impurity spin distribution in ferromagnets can be changed and magnon amplification obtained. Absorption of the nonresonant radiation is saturated as the field increases.
Catalyst-free in-plane growth of high-quality ultra-thin InSb nanowires
Authors: He Fengyue , Wen Lianjun , Hou Xiyu , Li Lin-Han , Liu Lei , Zhuo Ran , Tan Ping-Heng , Pan Dong , Zhao Jianhua
Published: November 2024

InSb nanowires (NWs) show an important application in topological quantum computing owing to their high electron mobility, strong spin–orbit interaction, and large g factor. Particularly, ultra-thin InSb NWs are expected to be used to solve the problem of multiple sub-band occupation for the detection of Majorana fermions. However, it is still difficult to epitaxially grow ultra-thin InSb NWs due to the surfactant effect of Sb. Here, we develop an in-plane self-assembled technique to grow catalyst-free ultra-thin InSb NWs on Ge(001) substrates by molecular-beam epitaxy. It is found that ultra-thin InSb NWs with a diameter as small as 17 nm can be obtained by this growth manner. More importantly, these NWs have aspect ratios of 40–100. We also find that the in-plane InSb NWs always grow along the [110] and [11¯0] directions, and they have the same {111} facets, which are caused by the lowest-surface energy of {111} crystal planes for NWs grown with a high Sb/In ratio. Detailed structural studies confirm that InSb NWs are high-quality zinc blende crystals, and there is a strict epitaxial relationship between the InSb NW and the Ge substrate. The in-plane InSb NWs have a similar Raman spectral linewidth compared with that of the single-crystal InSb substrate, further confirming their high crystal quality. Our work provides useful insights into the controlled growth of in-plane catalyst-free III–V NWs.
A quantum computing measurement and control system with an FPGA-based scheduling system
Authors: Liu Yijun , Li Yi
Published: November 2024

Large-scale qubit systems represent the future of superconducting quantum computing. As the number of qubits and functions increases, the current qubit control architectures struggle to achieve large-scale expansion. To address this issue, we have developed a field-programmable gate array-based scheduling system, which serves as a control architecture deployed on measurement and control hardware. This system achieves the generation of multi-channel long sequence pulses using minimal storage space, with reusable envelope and instruction designs. The envelopes and instructions are preloaded into the electronics, with each instruction corresponding to a different segment of the output waveform. The architecture we designed allows for extended pulse control lengths and more complex experiments without the requirement for external storage resources. We present the resource utilization of the implementation and compare it with previous measurements under different qubit counts. To verify the functionality of the system, we conducted a series of performance tests and characterization experiments on the deployed electronics. The measured single-qubit relaxation time T1 is 34.1 μs, and the dephasing time T2* is 25.8 μs. We characterized the quality of the control pulses using a randomized benchmarking protocol, achieving an average fidelity of 99.962%.
Impact of elevated carbon dioxide and temperature on crop yield: A study of autonomous and nonautonomous systems
Authors: Yadav Akash , Jha Anjali , Misra A. K.
Published: November 2024

Agricultural crops are vital for human survival, forming the backbone of global food supply. However, the rising atmospheric carbon dioxide (CO2) level and the increasing temperature relative to the pre-industrial level are poised to impact the yields of essential staple food crops significantly. In this research, we propose and analyze a nonlinear mathematical model to investigate the effects of elevated CO2 and temperature on crop yield. Our model assumes that rising CO2 levels elevate the global average temperature, and the surface temperature initially boosts the growth rate of crops until a threshold is reached, after which the growth rate declines. We also incorporate seasonal variations into the model and perform a comprehensive analytical and numerical analysis of both the autonomous and associated nonautonomous systems. Our findings reveal a critical threshold for anthropogenic CO2 emissions, beyond which the crop yield starts to decrease. Notably, crops with high-temperature tolerance demonstrate higher yields even under elevated CO2 conditions, suggesting a viable strategy for mitigating climate change impacts: developing or utilizing crop varieties with enhanced temperature tolerance. Moreover, our analysis of the nonautonomous system uncovers periodic solutions when the corresponding autonomous system is stable. The nonautonomous system also exhibits complex dynamics, including higher-period oscillations and chaos, when the autonomous system undergoes limit-cycle oscillations. This study provides valuable insights into the interplay between CO2 level, global average surface temperature, and crop yield, offering potential strategies for safeguarding agricultural productivity in the face of climate change.
Development of a high-voltage power supply with ultra-low ripple of beam current on electron beam gun
Authors: Ma Xun , Li Songjie , Li Bo , Li Chen , Kang Longfei , Kang Chuanhui , Zhao Juan , Li Hongtao
Published: November 2024

Electron beam guns with grid-controlled electrodes and hot-cathodes are widely used in accelerator physics facilities, high-voltage electron beam welding machines, electron beam 3D additive manufacturing, x-ray sources, etc. The ripple of electron beam current is one of the most critical factors affecting beam quality, and the electron beam current ripple is generally more than 2% with traditional circuit topology. This paper presents the expression for beam current, high voltage, and bias voltage derived from experimental data on a certain electron beam gun. Furthermore, the main causes of affecting beam current ripple are analyzed, and a novel circuit topology is proposed. According to the ISO14744, Welding-Acceptance inspection of electron beam welding machines, a Faraday cup is used to collect the beam from the electron beam gun. In this paper, the ripple of the beam current of the electron gun driven by the traditional and proposed circuits is tested, respectively. The experimental results show that the ripple of beam current of the novel circuit topology can be achieved to within ±0.18% when the voltage is 150 kV and the beam current is 33 mA, lower than 10 percent of that of the traditional power supply. The stability of beam current is better than 5 μA at 150 kV and 3.3 mA.
Demonstration of Si-doped Al-rich regrown Al(Ga)N films on AlN/sapphire with >1015/cm3 carrier concentration using CCS-MOCVD reactor
Authors: Mukhopadhyay Swarnav , Seshadri Parthasarathy , Haque Mobinul , Xie Shuwen , Bai Ruixin , Sanyal Surjava , Wang Guangying , Gupta Chirag , Pasayat Shubhra S.
Published: November 2024

Thin Si-doped Al-rich (xAl > 0.85) regrown Al(Ga)N layers were deposited on AlN on sapphire template using metal-organic chemical vapor deposition (MOCVD) techniques. The optimization of the deposition conditions, such as temperature (1150 °C), V/III ratio (750), deposition rate (0.7 Å/s), and Si concentration (6 × 1019/cm3), resulted in a high charge carrier concentration (> 1015 cm−3) in the Si-doped Al-rich Al(Ga)N films. A pulsed deposition condition with pulsed triethylgallium and a continuous flow of trimethylaluminum and ammonia was employed to achieve a controllable Al composition xAl > 0.95 and to prevent unintended Ga incorporation in the AlGaN material deposited using the close-coupled showerhead reactor. Also, the effect of unintentional Si incorporation on free charge carrier concentration at the regrowth interface was studied by varying the thickness of the regrown Al(Ga)N layer from 65 to <300 nm. A maximum charge carrier concentration of 4.8 × 1016 and 7.5 × 1015/cm3 was achieved for Al0.97Ga0.03N and AlN films with thickness <300 nm compared to previously reported n-Al(Ga)N films with thickness ≥400 nm deposited using MOCVD technique.
Propagation velocity measurements of substrate phonon bursts using MKIDs for superconducting circuits
Authors: Moshel Guy , Rabinowitz Omer , Blumenthal Eliya , Hacohen-Gourgy Shay
Published: November 2024

High-energy bursts in superconducting quantum circuits from various radiation sources have recently become a practical concern due to induced errors and their propagation in the chip. The speed and distance of these disturbances have practical implications. We used a linear array of multiplexed MKIDs on a single silicon chip to measure the propagation velocity of a localized high-energy burst, introduced by driving a normal metal-insulator-superconductor (NIS) junction. We observed a reduction in the apparent propagation velocity with NIS power, which is due to the combined effect of reduced phonon flux with distance and the existence of a minimum detectable QP density in the MKIDs. A simple theoretical model is fitted to extract the longitudinal phonon velocity in the substrate and the conversion efficiency of phonons to QPs in the superconductor.
Observation of interface-induced nonlocal spin-torques from Gd/Pt interface
Authors: Dutta Sutapa , Tulapurkar Ashwin A. , Bose Arnab
Published: November 2024

We investigate spin–orbit torques (SOTs) generated by Gd/Pt and Ti/Pt interfaces by performing spin-torque ferromagnetic resonance measurements at room temperature. We report a sizable spin-current created by the Gd/Pt interface, exhibiting the damping-like-torque efficiency per unit electric field, ξDLE=−8 ± 0.6×104ℏ2e(Ωm)−1 as observed in Gd(5 nm)/Pt(1.5 nm)/Py(3 nm-6 nm)/Pt(1.5 nm) heterostructures. This interface-induced spin-current is attributed to the vertical electric field produced by the broken structural inversion symmetry, with a work function difference of 2.75 eV between Gd and Pt. This is further substantiated by varying the thickness of the Gd-layer. We compare these results with the Ti/Pt interface, which has a work function difference of 1.3 eV, by implementing Ti(5 nm)/Pt(1.5 nm)/Py(3 nm-6 nm)/Pt(1.5 nm) heterostructures. We find that the spin-current induced by the Ti/Pt interface is too small to overcome the remnant SOTs caused by the asymmetrically grown Pt layers on both sides of Py. Our work reveals the role of interface-induced spin currents for practical applications, which can be leveraged to produce robust spin torques that complement the bulk spin-Hall torque.
Charge carrier recombination in TiO2 and SrTiO3 single crystals: Impact of CoOx cocatalyst loading
Authors: Zhang Endong , Takayoshi Toru , Pan Zhenhua , Kato Masashi
Published: November 2024

Titanium dioxide (TiO2) and strontium titanate (SrTiO3) are widely used photocatalytic materials in photoelectrochemical (PEC) water-splitting processes. Recent advancements have aimed at improving energy conversion efficiency by loading cobalt oxide (CoOx) cocatalysts onto these materials' surfaces to enhance O2 evolution and capture photogenerated holes. Charge carrier recombination plays a crucial role in PEC reactions. This investigation explores the impact of CoOx loading on various crystal faces on the charge carrier recombination dynamics in TiO2 and SrTiO3 single crystals using the microwave photoconductivity decay (μ-PCD) technique. The results indicate that CoOx loading increases the charge carrier recombination for both TiO2 and SrTiO3 across all crystal faces, as observed from the decay curves. Additionally, different tendencies of the injected photon density and temperature dependence of the carrier lifetime, derived from μ-PCD curves, reveal that CoOx loading on TiO2 surfaces introduces the new surface recombination center that dominates the charge carrier recombination. In contrast, for SrTiO3, the surface recombination center remains unchanged across all crystal faces. Consequently, these findings suggest that while CoOx loading on SrTiO3 surfaces does not affect the charge carrier dynamics and remains effective for water splitting, it poses a risk of enhancing carrier recombination and reducing efficiency in TiO2.
Destabilization of water–oil emulsions by flowing them through constricted capillaries
Authors: Botti T. , Hutin A. , Carvalho M. S.
Published: November 2024

Oil is usually produced in the form of water-in-oil (w/o) stable emulsions due to the presence of natural stabilizing components in the oil phase. Oil and water phases need to be separated by coalescence of the dispersed drops. Different strategies are used to destabilize the produced emulsions and promote coalescence. In this work, we propose and qualitatively evaluate a new method to enhance water drop coalescence in stable water–oil emulsions. First, stable water-in-oil emulsions were prepared using a nonionic surfactant (Span 80) dissolved in mineral oil (Primol 352). Visualization experiments showed that the emulsion stability comes from the formation of small droplets along the water drop interface by spontaneous emulsification, leading to a droplet-rich rough interface. Water drops that are brought into contact after the formation of the rough interface do not coalesce, leading to very stable emulsions. Later, the water drops with a droplet-rich interface are passed through a capillary tube with a constriction smaller than the drop diameter. As the drop flows through the capillary throat, its surface area is increased and a strong shear stress is imposed along its surface, removing the droplets from the interface, which favors coalescence. A free water phase formed by water drop coalescence can be observed after flowing the stable water-in-oil emulsion through the constricted capillary.
Non-linear effects in α-Ga2O3 radiation phenomena
Authors: Klevtsov Anton , Karaseov Platon , Azarov Alexander , Karabeshkin Konstantin , Fedorenko Elizaveta , Titov Andrei , Kuznetsov Andrej
Published: November 2024

The rhombohedral phase of gallium oxide (α-Ga2O3) is of interest because of its highest bandgap among the rest of the Ga2O3 polymorphs, making it particularly attractive in applications. However, even though the ion beam processing is routinely used in device technology, the understanding of radiation phenomena in α-Ga2O3 is not mature. Here, we study non-linear effects for radiation disorder formation in α-Ga2O3 by varying both the defect generation rate and the density of collision cascades, enabled by comparing monoatomic and cluster ion implants, also applying systematic variations of ion fluxes. In particular, we show that the collision cascade density governs the surface amorphization rates, also affected by the ion flux variations. These trends are explained in terms of the non-linear in-cascade and inter-cascade defect interactions occurring during ballistic and dynamic defect annealing stages. As such, these data reveal new physics of the radiation phenomena in α-Ga2O3 and may be applicable for more predictive ion beam processing of α-Ga2O3-based devices.
Spatial and reconfigurable control of photoluminescence from single-layer MoS2 using a strained VO2-based Fabry–Pérot cavity
Authors: Nakayama Koyo , Toida Shota , Endo Takahiko , Inada Mitsuru , Sato Shingo , Tani Hiroshi , Watanabe Kenji , Taniguchi Takashi , Ueno Keiji , Miyata Yasumitsu , Matsuda Kazunari , Yamamoto Mahito
Published: November 2024

We investigated the photoluminescence (PL) from single-layer MoS2 on VO2 platelets grown on SiO2, where the insulating and metallic phases can coexist above a bulk transition temperature of 340 K, due to the inhomogeneous strain. We found that the intensity of PL from MoS2 on metallic VO2 is higher than that on the insulating counterpart, resulting in spatially varying PL even at the sub-micrometer scale. In contrast to the intensity, the PL peak energies were observed to be nearly identical on insulating and metallic VO2, indicating that the influences of charge transfer, strain, and dielectric screening on MoS2 are comparable, regardless of the phase state. Thus, the observed difference in PL intensity is due to the difference in refractive indices of insulating and metallic VO2, leading to the phase-dependent Fabry–Pérot interference effect. We performed numerical simulations for the emission from MoS2 supported on the VO2-based Fabry–Pérot interferometer. The calculated emission intensity ratio on insulating and metallic VO2 well reproduces the experimental observations. These results suggest a strategy for controlling PL from two-dimensional semiconductors in a spatial and reconfigurable manner.
Wave steepening and shock formation in ultracold neutral plasmas
Authors: Warrens M. K. , Inman N. P. , Gorman G. M. , Husick B. T. , Bradshaw S. J. , Killian T. C.
Published: November 2024

We present observations of wave steepening and signatures of shock formation during expansion of ultracold neutral plasmas formed with an initial density distribution that is centrally peaked and decays exponentially with distance. The plasma acceleration and velocity decrease at large distance from the plasma center, leading to central ions overtaking ions in the outer regions and the development of a steepening front that is narrow compared to the size of the plasma. The density and velocity change dramatically across the front, and significant heating of the ions is observed in the region of steepest gradients. For a reasonable estimate of electron temperature, the relative velocity of ions on either side of the front modestly exceeds the local sound speed (Mach number M≳1). This indicates that by sculpting steep density gradients, it is possible to create the conditions for shock formation, or very close to it, opening a new avenue of research for ultracold neutral plasmas.