bluuebunny/crossref_metadata_2025 huggingface dataset:
The Influence of the Partner's Involvement in Antenatal Genetic Group Counseling on Pregnant individuals' Scores on Tests of Vital Knowledge Relating to Pregnancy
Authors: Anansirikasem Teerawat , Kongsomboon Kittipong , Hanprasertpong Tharangrut
Published: March 2023

Objective Physicians and other medical providers counsel patients to provide them with most important information and available medical service options. How to provide the most effective antenatal counseling is an important focus among experts. Our study focuses on the influence of the partner's involvement during antenatal genetic group counseling (AGGC). This study aimed to compare the ratio of pregnant individuals who have knowledge score improvement after AGGC, with a focus on pregnant individuals who attend counseling with/without their partner and to identify other possible factors that could influence the knowledge improvement.

Study Design A prospective cohort study was conducted. Pregnant individuals were assessed for their knowledge by using a self-questionnaire prior to and immediately after AGGC.

Results A total of 553 pregnant women were enrolled; 310 and 243 participants attended the AGGC without and with their partner, respectively. The ratio of the participants who increased their overall knowledge score was significantly higher after the AGGC for those who were with partner compared with those without. The medians (Q1–Q3) of the overall knowledge scores before and after the AGGC were 32 (29–36) and 36 (31–39) in the AGGC with their partner, respectively, and 33 (30–36) and 35 (32–39) in the AGGC without their partner, respectively. Knowledge of trisomy-21 screening of all participants got the lowest score and less improvement when compared with other topics.

Conclusion Partner's involvement in the AGGC was associated with a higher ratio of the participants who increased their overall knowledge score when comparing the scores prior to and immediately after the AGGC.
Pd-Catalyzed MIA-Directed Methoxylation of Phenylalanines: A Combined Experimental and Computational Study
Authors: Yu Fang , Tang Wen-Jun , Dai Shu-Min , Yuan Yue , Wang Shuai , He Yu-Peng
Published: March 2023

The direct methoxylation of substituted phenylalanines has been accomplished via methoxyiminoacyl (MIA)-mediated Pd-catalyzed C–H functionalization. A diverse array of ortho-methoxylated phenylalanine derivatives are efficiently generated in good to high yields. KIE study has shown that the oxhydryl cleavage step is the rate-limiting step. The computational data show that the participation manner of methanol has a great influence on the energy barriers of transition states during the C(sp2)–O formation stage. The pathway containing stepwise deprotonation and reductive elimination is superior to that of a concerted deprotonation-methoxylation.
Behavior Problems in Children With Epilepsy (Age 6–14 years): A Prospective Observational Study
Authors: Solanki Rahul , Ghanghoriya Pawan , Sisodia Deepti , Lazarus Monica
Published: March 2023

Objectives

Epilepsy's psychological effects are variable, some may experience a few mental health issues while some may experience serious problems such as anxiety, depression, attention deficit hyperkinetic disorder (ADHD), and mood disorders. Hence, there is a need to screen these problems at an early age for timely intervention. So, our study was conducted to determine the prevalence of emotional and behavioral problems in children with epilepsy.

Material and Methods

This was a prospective observational study on 111 children, 6 to 14 years of age. The overall prevalence of emotional and behavioral problems in childhood was determined by calculating the percentage of children with child behavior checklist score indicative of specific emotional and behavioral problems. The prevalence for specific morbidities was also calculated and reported separately for each condition. Results were presented in the form of tables, charts, graphs, and narratives.

Results

The overall prevalence of emotional and behavioral problems in children was 38.7%. Attention problem (13.5%), aggressive behavior (10.8%), social problems (8.1%), and withdrawal/depression (6.3%) were the four leading syndromes. The prevalence of emotional and behavioral problems was significantly associated with the age of onset of epilepsy, type of epilepsy, frequency of seizures, and antiepileptic drug therapy used by child.

Conclusion

As there is a higher prevalence of emotional and behavioral problems in children with epilepsy, age of onset, frequency of seizure, and duration of diseases were found to be significantly associated with the occurrence of behavioral problems. Therefore, prompt and early screening for these problems, as well as integrated management consisting of pharmacotherapy, behavioral modification, parental education and counselling, psychotherapy and psychoeducation would help to reduce their effect in these patients.
Family Burden and Epilepsy Surgery in Children with Drug-Resistant Epilepsy
Authors: Hoyer Sebastian , Makridis Konstantin L. , Atalay Deniz A. , Thomale Ulrich-W , Prager Christine , Elger Christian E. , Kaindl Angela M.
Published: March 2023

Introduction Family burden (FB) in pediatric patients with drug-resistant epilepsy (DRE) is significantly higher than that in children with non-DRE. Epilepsy surgery is an established approach to treat DRE, and this study examines the impact of pediatric epilepsy surgery on FB.

Methods We retrospectively analyzed data of families and pediatric patients with focal structural DRE treated with epilepsy surgery at our epilepsy center from April 2018 to November 2021. We examined the relationship between cognitive, behavioral, and epilepsy-specific data and the FB measured with the German version of the Impact on Family Scale before and after epilepsy surgery.

Results The study cohort included 31 children with DRE at a mean age of 9 years at surgery (range = 0–16) and a mean epilepsy duration of 3 years (range = 0–14). Cognitive impairment correlated with FB in children with DRE prior to surgery. At the last assessment, 14.5 months (mean, range = 6–24) after epilepsy surgery, 87.2% of patients were seizure-free, FB values had decreased by 75.0%, and behavioral problems had decreased by 85,7%. Cognitive functions remained stable following epilepsy surgery.

Conclusion In children with DRE, epilepsy surgery reduces FB. Given the considerable impact of families on the development and wellbeing of their children, the impact of epilepsy surgery should be communicated to affected families.
Platelet Parameters as Biomarkers for Thrombosis Risk in Cancer: A Systematic Review and Meta-analysis
Authors: Malte Anne Lind , Højbjerg Johanne Andersen , Larsen Julie Brogaard
Published: March 2023

Cancer-associated thrombosis (CAT) is a major cause of both morbidity and mortality in cancer patients. Platelet count has been investigated as a predictor of CAT in various settings while knowledge on platelet activation parameters is sparse. This report provides a systematic review and meta-analysis on available literature on associations between platelet count and/or function and arterial and venous thrombosis in adult cancer patients. The review was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement. PubMed and Embase were searched up to March 2022. The National Heart, Lung, and Blood Institute's tools were used for quality assessment. In total, 100 studies were included which investigated the association between CAT and platelet count (n = 90), platelet indices (n = 19), and platelet function/activation markers (n = 13) in patients with solid cancers (n = 61), hematological cancers (n = 17), or mixed cancer types (n = 22). Eighty-one studies had venous thrombosis as their outcome measure, while 4 had arterial thrombosis and 15 studies had both. We found significantly elevated odds ratio of 1.50 (95% confidence interval: 1.19–1.88) for thrombosis with higher platelet counts. We saw a tendency toward an association between markers of platelet activation in forms of mean platelet volume and soluble P selectin and both arterial and venous thrombosis. Only one study investigated dynamic platelet function using flow cytometry. In conclusion, platelet count is associated with CAT across different cancer types and settings. Platelet function or activation marker analysis may be valuable in assisting thrombosis risk assessment in cancer patients but is sparsely investigated so far.
Room temperature ferromagnetic behavior of GaN nanoceramics
Authors: Zaleski A. J. , Gluchowski P. , Stręk W. , Tran L. M. , Babij M.
Published: March 2023

It is shown that the GaN nanoceramics fabricated by low-temperature high-pressure technique exhibit ferromagnetic behavior. The measurements reveal that the magnetization of GaN nanoceramics increased with the sintering pressure to 8 GPa applied in the fabrication process of nanoceramics. It is suggested that the magnetostriction mechanism is responsible for the observed increase of ferromagnetism in GaN nanoceramics. The magnetization of GaN nanoceramic measured at 2 K has decreased nonlinearly with applied pressure by orders of magnitude, reaching a minimum at 4 GPa. It was shown that the magnetization of GaN nanoceramics demonstrates hysteresis behavior.
Ultrathin graphitic carbon nitride (g-C3N4) nanosheets: Synthesis, properties, and photocatalytic application
Authors: Miśta W. , Dovbeshko G. , Chaika M. , Wiewiórski P. , Ptak M. , Boiko V. , Stręk W.
Published: March 2023

In recent years graphitic carbon nitride (g-C3N4) has been considered the most popular candidate for replacing graphene and other similar materials in various applications. The g-C3N4 has unique electronic and mechanical properties, huge photoluminescence in the wide optical region, and promising properties in energy conversion and storage, water splitting, etc. Here we show a simple method of bulk g-C3N4 (BCN) synthesis using thermal polymerization of melamine and ultrathin 2D g-C3N4 nanosheets (NCN) prepared by ultrasonic exfoliation of BCN in water. The g-C3N4 samples were tested with XRD, FTIR, Raman, luminescence spectroscopy, and N2 adsorption at 77 K. We characterize its photocatalytic properties in H2 evolution by direct water splitting. We utilize the low-cost 10 W white LEDs photoreactor with visible light and flow conditions. In the water-splitting reaction, we found that the NCN were about 5 times more reactive than the primary BCN sample.
Influence of low temperature on white light emission from graphene-based microchip
Authors: Chaika M. , Tomala R. , Oleszko M. , Stręk W.
Published: March 2023

The laser-induced white emission of the graphene-based microchip was investigated under near-infrared region laser irradiation. The emission was characterized by an excitation threshold and an exponential dependence on the pump laser power. A decrease in temperature caused an increase in both the number of absorbed photons and the emission threshold. This dependence can be explained by the multiphoton ionization process in (sp2, sp3) hybridized domains.
Crystal structure and low-temperature magnetic properties of R2Au2Pb (R = Y, La–Nd, Sm, Gd–Lu) plumbides
Authors: Gulay Lubomir D. , Kaczorowski Dariusz
Published: March 2023

Polycrystalline samples of the ternary compounds R2Au2Pb (R = Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were studied by means of powder X-ray diffraction and magnetic measurements. All these materials were found to crystallize with a tetragonal crystal structure of the Er2Au2Sn type (space group P42/mnm, Pearson code tP20). The Y-, La-, and Lu-based phases were established to be diamagnetic, while Yb2Au2Pb was characterized as an intermediate valence system due to an unstable 4f shell. All the other R2Au2Pb ternaries were found to order antiferromagnetically at low temperatures (TN in the range 2–30 K) due to the localized magnetic moments carried on trivalent R3+ ions.
Local pairs in high-temperature superconductors: The concept of pseudogap
Authors: Solovjov A. L. , Rogacki K.
Published: March 2023

The origin of the high-temperature superconductivity of cuprates remains a subject of debate after almost four decades of investigation. One of the main questions — what is the physics behind the mechanism of superconducting pairing, which makes it possible to obtain real Cooper pairs at temperatures much higher than 100 K, remains open. It is believed that the answer can be obtained by the studying the properties of cuprates in the normal state above Tc, where the pseudogap (PG) opens at T* >> Tc. The number of papers devoted to the study of PG is extraordinarily large, but its physics also remains in question. In cuprates, the question arises whether the pseudogap phase arises exclusively due to antiferromagnetic fluctuations, spin or charge density waves, or whether it can be explained by the formation below T* of specific paired fermions, the so-called local pairs. We review studies on both approaches to PG that should clarify this issue. In addition to theoretical considerations, we analyze and discuss various experimental results of fluctuation conductivity and PG measurements, as well as magnetic measurements, in an attempt to prove the decisive role of local pairs in the formation of the PG state. Accordingly, various types of supposed magnetic interactions can be considered as possible mechanisms of superconducting pairing in high-temperature superconductors.
Anisotropy of thermal expansion and compressibility of non-centrosymmetric (H3AmGP)SiF6
Authors: Rejnhardt Piotr , Daszkiewicz Marek
Published: March 2023

The crystal structure of the new compound 3-guanidinium-2-aminopropionic acid hexafluorosilicate was studied by single crystal X-ray diffraction at various temperature (100–400 K) and pressure conditions (10–4–0.75 GPa). Anisotropy of both thermal expansion and compressibility was correlated with the hydrogen bonding patterns and especially with the stiffness of small ring patterns. The measured second harmonic generation response for the studied compound is 0.3 that of potassium dihydrogen phosphate and is comparable to L-arginine chloride.
The study of electronic structure and optical properties of Ba2MnWO6 within density functional theory
Authors: Nguyen Thi Thu Ha , Sahakyan Mane , Tran Vinh Hung
Published: March 2023

Based on density functional theory, the electronic and optical properties of double perovskites Ba2MnWO6 were studied using the generalized gradient approximation. We have looked into four magnetic configurations, such as collinear antiferromagnetic AF-1, AF-2 and noncollinear antiferromagnetic AF-NC1, AF-NC2 structures. The obtained results show that the valence band maximum is mainly dominated by Mn-3d orbitals, while the conduction band minimum is mainly composed of W-5d orbitals. In addition, Ba2MnWO6 is shown as an indirect band gap semiconductor. The gap between two main t2g,↑ and e2g,↑ manifolds of Mn-3d states, located at about 1.9 and 1 eV below Fermi level, is initiated as consequence of splitting in crystal field. From calculated optical results, Ba2MnWO6 indicates excellent light absorption in the ultraviolet range. Consequently, this material promises potential optical applications, such as solar cell functional in ultraviolet light.
Experimental evidence of shock wave measurements with low-velocity (<100 m s−1) and fast dynamics (<10 ns) capabilities using a coupled photonic Doppler velocimetry (PDV) and triature velocity interferometer system for any reflector (VISAR) diagnostic
Authors: Boutoux G. , Chevalier J.-M. , Arrigoni M. , Berthe L. , Beuton R. , Bicrel B. , Galtié A. , Hébert D. , Le Clanche J. , Loillier S. , Loison D. , Maury P. , Raffray Y. , Videau L.
Published: March 2023

We present a series of shock-wave measurements on aluminum based on the use of a simultaneous Photon Doppler Velocimetry (PDV) and triature velocity interferometer system for any reflector. Our dual setup can accurately measure shock velocities, especially in the low-speed range (<100 m s−1) and fast dynamics (<10 ns) where measurements are critical in terms of resolution and unfolding techniques. Especially, the direct comparison of both techniques at the same measurement point helps the physicist in determining coherent settings for the short time Fourier transform analysis of the PDV, providing increased reliability of the velocity measurement with a global resolution of few m s−1 in velocity and few ns FWHM in time. The advantages of such coupled velocimetry measurements are discussed, as well as new opportunities in dynamic materials science and applications.
Radiation, optical, power flow, and electrical diagnostics at the Z facility: Layout and techniques utilized to operate in the harsh environment
Authors: Webb T. J. , Bliss D. E. , Chandler G. A. , Dolan D. H. , Dunham G. , Edens A. , Harding E. , Johnston M. D. , Jones M. C. , Langendorf S. , Mangan M. , Maurer A. J. , McCoy C. A. , Moore N. W. , Presura R. , Steiner A. M. , Wu M. , Yager-Elorriaga D. A. , Yates K. C.
Published: March 2023

The Z machine is a current driver producing up to 30 MA in 100 ns that utilizes a wide range of diagnostics to assess accelerator performance and target behavior conduct experiments that use the Z target as a source of radiation or high pressures. We review the existing suite of diagnostic systems, including their locations and primary configurations. The diagnostics are grouped in the following categories: pulsed power diagnostics, x-ray power and energy, x-ray spectroscopy, x-ray imaging (including backlighting, power flow, and velocimetry), and nuclear detectors (including neutron activation). We will also briefly summarize the primary imaging detectors we use at Z: image plates, x-ray and visible film, microchannel plates, and the ultrafast x-ray imager. The Z shot produces a harsh environment that interferes with diagnostic operation and data retrieval. We term these detrimental processes “threats” of which only partial quantifications and precise sources are known. We summarize the threats and describe techniques utilized in many of the systems to reduce noise and backgrounds.
Reflection power suppression for solid state amplifiers with combiner optimization
Authors: Chen Shengyi , Li Xiao , Zhu Junyu , Zhang Chunlin , Long Wei , Liu Yang , Liu Shenghua , Lu Zhijun
Published: March 2023

The application of high-power solid state amplifiers (SSAs) in accelerator facilities is increasing, and equipment failure caused by reflected power is the main risk to their long-term operation. High-power SSAs often comprise multiple power amplifier modules. Full power reflection is more likely to damage the modules in SSAs if the amplitudes of the modules are unequal. Optimization of the power combiners is an effective means for improving the stability of SSAs under high power reflection. This study analyzes the mechanisms and conditions of reflected power generation using the scattering parameters of the combiner and proposes an optimization scheme for the combiner. The simulation and experimental results show that some modules may receive reflected power as high as nearly four times the rated power of one module when the SSA meets certain conditions, which could damage the modules. The maximum reflected power can be effectively reduced and the anti-reflection ability of SSAs can be improved by optimizing the combiner parameters to suppress the maximum reflected power.
Theoretical and experimental research on two-phase flow image reconstruction and flow pattern recognition
Authors: Zhang Guoyuan , Wang Liewen , Wang Hao , Chen Yu , Dang Jiaqi
Published: March 2023

Two-phase flow is a kind of complex fluid flow state, and the flow pattern characteristics are very difficult to obtain accurately. First, the principle of two-phase flow pattern image reconstruction based on electrical resistance tomography technology and the complex flow pattern recognition method are developed. Next, the back propagation (BP), wavelet, and radial basis function (RBF) neural networks are applied to the two-phase flow pattern image identification process. The results show that the RBF neural network algorithm has higher fidelity and faster convergence speed than the BP and wavelet network algorithms, and the fidelity is more than 80%. Then, deep learning of the pattern recognition algorithm fusing the RBF network and convolution neural network is proposed to improve the precision of the flow pattern identification. Additionally, the recognition accuracy of the fusion recognition algorithm is more than 97%. Finally, a two-phase flow test system is constructed, the test is finished, and the correctness of the theoretical simulation model is verified. The research process and results provide important theoretical guidance for the accurate acquisition of two-phase flow patterns.
Laser emission at 428 nm in N2+: Competition between two- and three-level amplification
Authors: Danylo R. , Zhang X. , Lisova A. , Houard A. , Liu Y. , Tikhonchuk V. , Mysyrowicz A.
Published: March 2023

Lasing of N2+ at 428 nm is studied as a function of the delay dt between two 800 nm ultrashort pumping pulses from a Ti:sapphire laser. This lasing corresponds to a population-inverted transition between levels B2Σu+(0) and X2Σg+(1) of a singly ionized nitrogen molecule. An important erasing of laser emission is observed under pumping with two consecutive pulses separated by large delays −20 ps < dt < +20 ps. From an analysis of the quenching results, we conclude that the mechanism of lasing corresponds to a coherent two-photon amplification scheme. Our results show that a two-photon process can dominate over a population-inverted one-photon amplification.
Efficient magnetization reversal by self-generated spin–orbit torque in magnetic bulk Rashba materials
Authors: Li Xin , Fu Zhenxiao , He Yu , Yu Xi , Yang Yumeng , Li Weimin
Published: March 2023

In this paper, we demonstrate that V0.027Bi0.973TeI, a material with both giant bulk Rashba effect and ferromagnetism, can reverse its magnetization by self-generated spin–orbit torque. Through first-principles calculation, it is found that the giant bulk Rashba effect arises from both bulk space inversion asymmetry and strong spin–orbital coupling, while the ferromagnetism originates from the itinerant d-electrons of doped element vanadium. More importantly, its field-like spin–orbit torque efficiency is determined to be as high as 4.53 × 10−4 mT/(A cm−2), which is more than two orders of magnitude higher than that typically observed in magnetic heterostructures. It is further shown that by using such magnetic bulk Rashba material to form a homogenous spintronic device, the power consumption for magnetization switching can be significantly reduced.
A new light on the FKMM invariant and its consequences
Authors: De Nittis Giuseppe , Gomi Kiyonori
Published: March 2023

“Quaternionic” vector bundles are the objects that describe topological phases of quantum systems subjected to an odd time-reversal symmetry (class AII). In this work, we prove that the Furuta–Kametani–Matsue–Minami (FKMM) invariant provides the correct fundamental characteristic class for the classification of “Quaternionic” vector bundles in dimension less than or equal to three (low dimension). The new insight is provided by the interpretation of the FKMM invariant from the viewpoint of the Bredon equivariant cohomology. This fact, along with basic results in equivariant homotopy theory, allows us to achieve the expected result.
The enhanced soliton propagation and energy transfer in the coupled drift wave and energetic-particle-induced geodesic acoustic mode system
Authors: Chen Ningfei , Wei Guangyu , Qiu Zhiyong
Published: March 2023

The evolution of the coupled drift wave (DW) and energetic-particle-induced geodesic acoustic mode (EGAM) nonlinear system is investigated using the fully nonlinear coupled DW-EGAM two-field equations with emphasis on the turbulence spreading in the form of soliton and the nonlinear energy transfer between DW and EGAM. Four scenarios with different combinations of EGAM initial amplitudes and linear EGAM growth rates are designed to clarify the contributions of linear excitation of EGAM by EPs and nonlinear excitation by DWs to the nonlinear evolution. In the presence of the linear EPs drive, the soliton propagation is enhanced, due to the generation of small radial scale structures. Two conservation laws of the nonlinear system are derived, including the energy conservation law. It is found that the energy of DW always decreases and that of EGAM always increases, leading to the regulation of DW by EGAM.
Flexible thermoelectrics: From energy harvesting to human–machine interaction
Authors: Wang Yao , Yang Lu , Zheng Yantao , Wang Dangxiao , Deng Yuan
Published: March 2023

Thermoelectrics is the simplest technology applicable for direct energy conversion between heat and electricity. After over 60 years of fruitful research efforts, recent boom in flexible electronics has promoted the rapid development of flexible thermoelectrics with rising performances, discovery of new materials and concepts, unconventional device configuration, and emerging applications not possible for traditional thermoelectric (TE) semiconductors. In this Perspective, we first overview representative flexible TE materials, then discuss recent breakthroughs for flexible TE devices assembled from various types of TE materials employing different technical routes. They exhibit promising power generation and sensing performances, and aim for applications in wearable electronics, such as the power supply harvesting heat from body for low-power electronics, temperature sensors for tactile e-skin, and newly emerged application as a thermo-haptic device in an extended reality system.
Raman spectroscopic studies on the evolution of interlayer coupling and stacking order in twisted bilayers and polytypes of WSe2
Authors: Paul Sourav , M. B. Abhijith , Ghosh Prasenjit , Paromita Chanda Prajna , Glavin Nicholas R. , Roy Ajit K. , Watanabe Kenji , Taniguchi Takashi , Kochat Vidya
Published: March 2023

Twisted 2D bilayers of van der Waals materials, a new class of quantum materials, offer pioneering advances in the field of nanoelectronics and photonics. As these layered materials can have various preferential stacking configurations with varying electronic behavior, it is important to have a characterization technique that can unambiguously probe the stacking order and interlayer interactions in 2D materials and twisted 2D homobilayers. In this work, we show that by using Raman spectroscopy, we can probe variations in the interlayer coupling of bilayer WSe2 stacked at different twist angles. The interlayer interactions are weakest at a twist angle of 30°, and the twisted bilayer system is almost equivalent to two decoupled monolayers of WSe2. Also we demonstrate Raman mapping as a quick imaging tool with capabilities of clear distinction between 2H and 3R polytypes of bilayer WSe2 and can be used to study various kirigami structures and bilayer nucleation centers commonly observed during chemical vapor deposition-based growth of WSe2. This work proves to be beneficial in the characterization of twisted bilayers of 2D materials and offer key insights into the optoelectronic properties of 2D materials and heterostructures.
Quantification and investigation of pressure fluctuation intensity in a multistage electric submersible pump
Authors: Yang Yang , Chen Xionghuan , Bai Ling , Yao Yulong , Wang Hui , Ji Leilei , He Zhaoming , Song Xiangyu , Zhou Ling
Published: March 2023

Pressure fluctuation is an important factor affecting the stability of rotating machinery. Electric submersible pumps (ESPs) are generally arranged in a multistage series structure, and its internal unsteady flow is extremely easy to propagate and develop in the lengthy flow passage, which brings about differences in the characteristics of pressure fluctuations in each stage. In contrast to the conventional method of processing pressure fluctuation signals, we propose a parameter called “energy flow density (EFD)” of pressure pulsation by analogy with the definition of wave intensity, in order to directly quantify the intensity of pressure fluctuations. Here, we study these pressure fluctuation characteristics using a typical three-stage ESP as the research object. We apply theoretical analysis, numerical simulation, and test verification. First, in comparisons between numerical predictions of pressure fluctuation and test results, the period, amplitude, and phase of pulsation curves are highly consistent, verifying the accuracy of the numerical method employed in this paper. Next, the mechanism underlying the pressure fluctuations and the characteristics of inter-stage interference are investigated through flow field analysis. Subsequently, the results of the evaluation of the pressure fluctuations based on EFD processing are compared with those obtained in the conventional way. The results are consistent in terms of characterizing the multistage ESP pressure fluctuation characteristics, but the conventional method does not reflect subtle differences due to inter-stage propagation and coupling. However, the EFD method combines the amplitudes of all signals and provides the intensity of pressure fluctuations directly, which reflects inter-stage differences. Our results provide a theoretical basis for improving the operational stability of ESPs connected in a multistage series and have practical engineering significance.
Unraveling the synergistic effect on ionic transport of ceria via the surface engineering for low-temperature ceramic fuel cells
Authors: Shah M. A. K. Yousaf , Lu Yuzheng , Mushtaq Naveed , Yousaf Muhammad , Zhu Bin
Published: March 2023

Recently, the multifunctional semiconductor CeO2 realized high ionic conductivity via surface conduction and delivered higher fuel cell performance. This indicates a promising strategy for the design of an electrolyte for the low-temperature ceramic fuel cell. In this study, we develop a ceria-based electrolyte by surface doping Bi into CeO2 to attain the CeBiO2 (BDC) electrolyte. The designed electrolyte is facilitated with an enriched O-vacancy surface layer, enabling high ionic conduction (0.20 S/cm) and excellent power density (1057 mW/cm2) at 530 °C. The difference in the Fermi level of BDC and CeO2 arises due to the surface doping, which entails the band alignment and establishes the space charge region, thereby constituting a built-in field enhancing the charge transportation and minimizing e-conduction. In order to assist the formation of O-vacancies in the design, the BDC electrolyte density functional theory calculation was also made. These findings suggest surface doping is the best approach to attaining excellent performance and designing electrolytes and electrodes for advanced low-temperature fuel cell technology.
Trap characteristics of hafnium oxide-based ferroelectric field-effect transistors measured by using a current transient method
Authors: Li Yilin , Zhu Hui , Liu Xing , Wang Xiaolei , Xu Hao , Pan Shijie , Xiang Jinjuan , Zhou Lixing , Yao Zhiwen , Sun Yerong , Feng Shiwei
Published: March 2023

The trap characteristics and polarization effect on the trapping behavior in Hf0.5Zr0.5O2 ferroelectric field-effect transistors were analyzed. The current transient that corresponds to the trapping/detrapping of charge carriers was measured and the exact time constant spectra were extracted. In accordance with the different time constants and activation energies as well as the dependence of the trapping behavior on the filling conditions, traps that originated from the oxygen vacancies in the Hf0.5Zr0.5O2 layer and from the Si/SiO2 interface trap states were identified. The detrapping peaks in time constant spectra showed a consistent changing trend with the variation of remanent polarization, confirming that the positive polarization enhanced the trapping of charge carriers injected from channel side to the ferroelectric layer.
Comparison of Matsubara dynamics with exact quantum dynamics for an oscillator coupled to a dissipative bath
Authors: Prada Adam , Pós Eszter S. , Althorpe Stuart C.
Published: March 2023

We report the first numerical calculations in which converged Matsubara dynamics is compared directly with exact quantum dynamics with no artificial damping of the time-correlation functions (TCFs). The system treated is a Morse oscillator coupled to a harmonic bath. We show that, when the system–bath coupling is sufficiently strong, the Matsubara calculations can be converged by explicitly including up to M = 200 Matsubara modes, with the remaining modes included as a harmonic “tail” correction. The resulting Matsubara TCFs are in near-perfect agreement with the exact quantum TCFs, for non-linear as well as linear operators, at a temperature at which the TCFs are dominated by quantum thermal fluctuations. These results provide compelling evidence that incoherent classical dynamics can arise in the condensed phase at temperatures at which the statistics are dominated by quantum (Boltzmann) effects, as a result of smoothing of imaginary-time Feynman paths. The techniques developed here may also lead to efficient methods for benchmarking system–bath dynamics in the overdamped regime.
Investigation of nitrogen fixation in low-pressure microwave plasma via rotational–vibrational NO and N2 kinetics
Authors: Samadi Bahnamiri Omid , Manaigo Filippo , Chatterjee Abhyuday , Snyders Rony , D’Isa Federico Antonio , Britun Nikolay
Published: March 2023

A pulsed microwave surfaguide-type discharge used for nitrogen fixation in N2–O2 gas mixtures is characterized by optical emission spectroscopy. Results show that both rotational and vibrational temperatures are elevated in the active zone near the waveguide, decaying along the discharge tube in both upstream and downstream. The characteristic length of optical emission from NO(A-X) transition gets contracted when pressure increases, specifically at P≥2 Torr. The degree of vibrational non-equilibrium (defined as the ratio between vibrational and rotational temperatures) is decreased by a factor of two when pressure changes from 0.6 to 10 Torr. Non-equilibrium likely disappears as the discharge pressure rises, resulting in a gas temperature elevation. A correlation between gas residence time, pulse duration, and characteristic times for different energy transfer channels is discussed. The rotational–vibrational dynamics differs for NO and N2 during the pulse. Both species lose vibrational excitation at the beginning of the pulse, whereas N2 gets re-excited again during the second half of the pulse, which may occur as a result of an efficient pumping-up effect through the vibrational–vibrational energy transfer. At the same time, vibrational relaxation of NO takes place primarily due to a strong vibrational–translational exchange via NO–O2 and NO–O collisions.
A scale-aware dispersion-relation-preserving finite difference scheme for computational aeroacoustics
Authors: Li Yanhui , Ren Yu-Xin
Published: March 2023

The numerical schemes for computational aeroacoustics (CAA) should have minimal dispersion and proper dissipation in order to accurately capture the amplitude and phase of waves. In this paper, we propose a scale-aware dispersion-relation-preserving (SA-DRP) finite difference scheme based on an improved scale sensor and a new dispersion control strategy. The scale sensor quantifies the local length scale of the solution in the form of the effective scaled wavenumber. The new feature of this scale sensor is the accurate prediction of the wavenumber for a pure sine wave. The new dispersion control strategy determines the dispersion parameter of the scheme in terms of the scale sensor. In contrast to the traditional dispersion-relation-preserving (DRP) scheme that minimizes the integral dispersion error, the new strategy directly solves the dispersion parameter by requiring the numerical dispersion relation to be equal to the exact one. As a result, precise dispersion relation can be realized within a very broad wavenumber range. The approximate dispersion relation analysis shows that the SA-DRP scheme maintains an accurate dispersion relation up to the scaled wavenumber k = 2.5. Moreover, the overshoot in the dispersion relation of the DRP scheme is not presented in that of the SA-DRP scheme. To suppress nonphysical oscillations, we also add proper dissipation that is adjusted automatically according to the effective scaled wavenumber. Several CAA benchmark test cases are presented to demonstrate the higher resolution and higher efficiency achieved by the proposed scheme compared with the conventional spectrally optimized schemes.
Simulation for pulse discharge performance of antiferroelectric capacitors
Authors: Xia Jiake , Yan Shiguang , Cao Fei , Chen Xuefeng , Lin Zhi-Sheng , Song Yunxiong , Chen Yonghong , Wang Genshui
Published: March 2023

The discharge performance of antiferroelectric (AFE) capacitors is complicated and difficult to simulate due to the nonlinear polarization behavior of AFE. In this work, a nonlinear model for pulsed discharge AFEs was proposed based on a combination of the Preisach model and Kirchhoff’s law. The model was driven by the data from first-order reversal curves and direct-current-bias (DC-bias) dielectric test measurements. Thus, the discharge behavior of the AFE can be studied without actual discharge experiments. Specifically, AFE discharge waveforms were calculated and evaluated for different size parameters and external circuit parameters that were conducive to compare the properties of different AFE materials. Moreover, the size effect of the capacitor on the discharge performance was discussed, which should draw the attention of researchers to prevent exaggerated conclusions. As a consequence, this method would fill the gap of AFE discharge simulation.
Simple realization of a hybrid controlled–controlled-Z gate with photonic control qubits encoded via eigenstates of the photon-number parity operator
Authors: Su Qi-Ping , Bin Liang , Zhang Yu , Yang Chui-Ping
Published: March 2023

We propose a simple method to realize a hybrid controlled–controlled-Z (CCZ) gate with two photonic qubits simultaneously controlling a superconducting (SC) target qubit, by employing two microwave cavities coupled to a SC ququart (a four-level quantum system). In this proposal, each control qubit is a photonic qubit, which is encoded by two arbitrary orthogonal eigenstates (with eigenvalues ±1, respectively) of the photon-number parity operator. Since the two arbitrary encoding states can take various quantum states, this proposal can be applied to realize the hybrid CCZ gate, for which the two control photonic qubits can have various encodings. The gate realization is quite simple because only a basic operation is needed. During the gate operation, the higher energy intermediate levels of the ququart are not occupied, and, thus, decoherence from these levels is greatly suppressed. We further discuss how to apply this gate to generate a hybrid Greenberger–Horne–Zeilinger (GHZ) entangled state of a SC qubit and two photonic qubits, which takes a general form. As an example, our numerical simulation demonstrates that high-fidelity generation of a cat–cat–spin hybrid GHZ state is feasible within current circuit QED technology. This proposal is quite general, which can be applied to realize the hybrid CCZ gate as well as to prepare various hybrid GHZ states of a matter qubit and two photonic qubits in other physical systems, such as two microwave or optical cavities coupled to a four-level natural or artificial atom.
In-plane anisotropy in van der Waals epitaxial MoS2 on MoO2(010)
Authors: Yang Dingbang , Jiang Junjie , Chen Jiaxin , Guo Xiao , Yang Xinhui , Zheng Xiaoming , Deng Chuyun , Xie Haipeng , Song Fei , Ouyang Fangping , Yuan Xiaoming , Chen Mingxing , Huang Han
Published: March 2023

Transition metal dichalcogenide based 2D/2D or 2D/3D van der Waals heterostructures exhibit superior properties for high-performance electronics, tunneling transistors, and catalysts. Here, we report on the fabrication of high quality 2D/3D MoS2/MoO2 heterostructures with an atomic clean interface by one-step chemical vapor deposition. Optical microscopy, atomic force microscopy, Raman spectroscopy, scanning electron microscopy, and energy dispersive spectroscopy measurements reveal the high-quality of as-grown samples and the specific epitaxial relationship between MoS2 and MoO2: MoS2[1¯1¯20]//MoO2[001] and MoS2[1¯100]//MoO2[201]. Photoluminescence and Kelvin probe force microscopy measurements combined with density functional theory calculations confirm the interfacial charge transfer from MoS2 to the underlying MoO2. Furthermore, MoO2 induced in-plane anisotropy in MoS2 was revealed using angle-resolved polarized Raman and photoluminescence spectroscopy with anisotropic ratios of 1.27 (Raman) and 1.29 (photoluminescence), respectively, which is most possibly attributed to anisotropic interfacial charge interactions. Our findings provide an excellent platform for the investigation on interfacial effects. Moreover, the in-plane anisotropy in MoS2 induced by MoO2 has expanded the application of isotropic MoS2 in the polarization-dependent fields.
Noise-specific beating in the higher-level Ramsey curves of a transmon qubit
Authors: Martinez L. A. , Peng Z. , Appelö D. , Tennant D. M. , Petersson N. Anders , DuBois J. L , Rosen Y. J.
Published: March 2023

In the higher levels of superconducting transmon devices and more generally charge sensitive devices, T2* measurements made in the presence of low-frequency time-correlated 1/f charge noise and quasiparticle-induced parity flips can give an underestimation of the total dephasing time. The charge variations manifest as beating patterns observed in the overlay of several Ramsey fringe curves and are reproduced with a phenomenological Ramsey curve model, which accounts for the charge variations. T2* dephasing times, which more accurately represent the total dephasing time, are obtained. The phenomenological model is compared with a Lindblad master equation model. Both models are found to be in agreement with one another and the experimental data. Finally, the phenomenological formulation enables a simple method in which the power spectral density for the low-frequency noise can be inferred from the overlay of several Ramsey curves.
Method for efficient excitation of selective vibration modes in pulsed laser photothermal actuation
Authors: Li J. , Liao X. , Meng Z. , Jiang Y.
Published: March 2023

Photothermal excitation based on thermoelastic mechanisms is widely used in non-destructive testing, precision operations, and driving micro-resonators. The narrow drive bandwidth of the high vibration mode in photothermal excitation limits its application to multi-mode drives. Controlling the laser’s irradiation position is an effective solution. In this study, we build a theoretical model to achieve selective and efficient excitation of different flexural vibration modes of beams with different supports. The model can be extended to other thermal and physical boundaries, which is validated by numerical simulations and experimental results. The results show that higher modes with complex periodic shapes can be efficiently excited by focusing the laser at the peak of the absolute value of the second derivative of the flexural mode while focusing the laser at the inflection point of the mode shape will result in extremely small amplitudes. Our study indicates that the thermal gradient plays a vital role in the oscillation of the beam. The conventional view assumes that the resonance of the photo-thermal excitation beam is caused by the local expansion and contraction of the material, which cannot completely explain the dependence principle of the photothermal vibration on the laser irradiation position. To investigate the mechanism of beam resonance under laser excitation, three excitation modes, unidirectional excitation, bidirectional in-phase excitation, and bidirectional anti-phase excitation, were established, and the conversion process of optical energy to mechanical energy under laser excitation was analyzed. These results provide new options for optimal excitation and multi-mode energy flow control in photothermal driving.
Model selection in atomistic simulation
Authors: Moussa Jonathan E.
Published: March 2023

There are many atomistic simulation methods with very different costs, accuracies, transferabilities, and numbers of empirical parameters. I show how statistical model selection can compare these methods fairly, even when they are very different. These comparisons are also useful for developing new methods that balance cost and accuracy. As an example, I build a semiempirical model for hydrogen clusters.
Fast mathematical modeling of partial-breach dam-break flow using a time-series field-reconstruction deep learning approach
Authors: Yan Xiaohui , Ao Ruigui , Mohammadian Abdolmajid , Liu Jianwei , Du Fu , Wang Yan
Published: March 2023

Mathematical modeling of dam-breach flow can provide a better understanding of dam failure events, which in turn helps people to reduce potential losses. In the present study, the smooth particle hydrodynamics (SPH) modeling approach was employed to simulate the three-dimensional (3D) partial-breach dam-break flow using two different viscosity models: the artificial viscosity and sub-particle-scale models. The validated and best-performing SPH model was further employed to conduct numerical experiments for various scenarios, which generated a comprehensive dataset. The current work also presents a novel time-series field-reconstruction deep learning (DL) approach: Time Series Convolutional Neural Input Network (TSCNIN) for modeling the transient process of partial-breach dam-break flow and for providing the complete flow field. This approach was constructed based on the long short-term memory and convolutional neural network algorithms with additional input layers. A DL-based model was trained and validated using the numerical data, and tested using two additional unseen scenarios. The results demonstrated that the DL-based model can accurately and efficiently predict the transient water inundation process, and model the influence of dam-break gaps. This study provided a new avenue of simulating partial-breach dam-break flow using the time-series DL approaches and demonstrated the capability of the TSCNIN algorithm in reconstructing the complete fields of transient variables.
Metamaterial based miniaturized broadband acoustic absorber
Authors: Dasila Santosh , Venkata Krishnamurthy Chitti , Subramanian V.
Published: March 2023

A miniaturized, broadband (800–5000 Hz) absorber with >95% absorption is proposed and realized. The absorber is designed using quarter-wavelength resonator tubes coiled as a rectangular “meta-atom.” The study describes the basic theoretical aspects of the absorber and compares it with the numerical simulations, fabrication, and experimental validation. The meta-atom, simple in design and made with fabrication-friendly materials, can provide greater spatial coverage through tiling over large surfaces.
Efficient silicon solar cells with highly conductive zirconium nitride electron-selective contacts
Authors: Tian Juan , Xu Kai , Wang Guangwei , Jiang Hongxu , Liu Yuan , Zhu Peng , Wang Deliang
Published: March 2023

Efficient carrier transport and suppressed interface recombination at back contact are essential for high-efficiency solar cells. Herein, we developed a zirconium nitride (ZrN) film with a low film resistivity of 1.6 × 10−4 Ω cm as an electron-selective contact for n-type silicon solar cells. Suitable band alignment of the n-Si/ZrN hetero-contact eliminates the interface barrier between Al and n-Si. Meanwhile, electrostatic potential induced by interfacial Si–O–Zr bonds assists electron extraction. The fill factor of devices has been significantly improved by incorporating a ZrN layer. After optimizing the thickness of ZrN and contact fraction, the champion ZrN-based device exhibited an efficiency of 19.7%, yielding a 23% enhancement compared with that without a ZrN interlayer.