bluuebunny/crossref_metadata_2025 huggingface dataset:
Vanishing of the anomalous Hall effect and enhanced carrier mobility in the spin-gapless ferromagnetic Mn2CoGa1−xAlx alloys
Authors: Zhang Cheng , Pan Shuang , Wang Peihao , Men Yuchen , Li Xiang , Bai Yuqing , Tang Li , Xu Feng , Xu Guizhou
Published: November 2023

Spin gapless semiconductor (SGS) has attracted much attention since its theoretical prediction, while concrete experimental hints are still lacking in the relevant Heusler alloys. Here in this work, by preparing the series alloys of Mn2CoGa1−xAlx (x = 0, 0.25, 0.5, 0.75, and 1), we identified the vanishing of the anomalous Hall effect in the ferromagnetic Mn2CoGa (or x = 0.25) alloy in a wide temperature interval, accompanying with growing contribution from the ordinary Hall effect. As a result, comparatively low carrier density (1020 cm−3) and high carrier mobility (150 cm2/V s) are obtained in the Mn2CoGa (or x = 0.25) alloy in the temperature range of 10–200 K. These also lead to a large dip in the related magnetoresistance at low fields. However, in a high Al content, although the magnetization behavior is not altered significantly, the Hall resistivity is, instead, dominated by the anomalous one, just analogous to that widely reported in Mn2CoAl. The distinct electrical-transport behavior of x = 0 and x = 0.75 (or 1) is presently understood by their possible different scattering mechanism of the anomalous Hall effect due to the differences in the atomic order and conductivity. Our work can expand the existing understanding of the SGS properties and offer a better SGS candidate with higher carrier mobility that can facilitate the application in the spin-injected related devices.
Theoretical study of the saturation and nature of the hydrogen bonds to gold
Authors: Yuan Qinqin , Feng Wanwan , Cheng Longjiu
Published: November 2023

Traditional hydrogen bonds are well-known to exhibit directionality and saturation. By contrast, gold involved hydrogen bonds (GHBs) have been extensively studied but remain lack of in-depth understanding towards the intrinsic nature and saturation property. This work exemplifies three series of complexes: [L–Au–L]−⋯(HF)n (L = H, CH3, (CH3)3; n = 1–8) containing GHBs to dig into the intrinsic nature with the aid of multiple theoretical analysis methods, finding that the formation of GHB is highly subject to orbital interactions along with steric hindrance. Moreover, the saturation level of GHBs largely depends on the ligand attached to the gold center, since different ligands typically possess varying electron-giving ability and steric volume. This work confirms the coexistence of as many as 6 GHBs for one Au atom and thoroughly studies the saturation level of GHBs, which will provide new insights into GHBs and facilitate future synthesis of more complicated gold complexes.
Tunable bandgap and Si-doping in N-polar AlGaN on C-face 4H-SiC via molecular beam epitaxy
Authors: Mondal Shubham , Wang Ding , Anhar Uddin Bhuiyan A F M , Hu Mingtao , Reddeppa Maddaka , Wang Ping , Zhao Hongping , Mi Zetian
Published: November 2023

N-polar AlGaN is an emerging wide-bandgap semiconductor for next-generation high electron mobility transistors and ultraviolet light emitting diodes and lasers. Here, we demonstrate the growth and characterization of high-quality N-polar AlGaN films on C-face 4H-silicon carbide (SiC) substrates by molecular beam epitaxy. On optimization of the growth conditions, N-polar AlGaN films exhibit a crack free, atomically smooth surface (rms roughness ∼ 0.9 nm), and high crystal quality with low density of defects and dislocations. The N-polar crystallographic orientation of the epitaxially grown AlGaN film is unambiguously confirmed by wet chemical etching. We demonstrate precise compositional tunability of the N-polar AlGaN films over a wide range of Al content and a high internal quantum efficiency ∼74% for the 65% Al content AlGaN film at room temperature. Furthermore, controllable silicon (Si) doping in high Al content (65%) N-polar AlGaN films has been demonstrated with the highest mobility value ∼65 cm2/V-s observed corresponding to an electron concentration of 1.1 × 1017 cm−3, whereas a relatively high mobility value of 18 cm2/V-s is sustained for an electron concentration of 3.2 × 1019 cm−3, with an exceptionally low resistivity value of 0.009 Ω·cm. The polarity-controlled epitaxy of AlGaN on SiC presents a viable approach for achieving high-quality N-polar III-nitride semiconductors that can be harnessed for a wide range of emerging electronic and optoelectronic device applications.
Scaling relations of dynamic hysteresis in pristine and BiFeO3 particle embedded P(VDF-TrFE) flexible ferroelectric membranes
Authors: Xu Lingfang , Yi Wenjun , Liang Shiheng , Xiao Haibo , Wang Ruilong , Yang Changping
Published: November 2023

The domain reversal dynamics of the pristine and 10 wt. % BiFeO3 nanoparticle-embedded P(VDF-TrFE) (polyvinylidene fluoride-trifluoroethylene) flexible ferroelectric membranes were investigated. A scaling relation of A∝fαE0β relevant to the domain reversal dynamics was eventually determined. The pristine P(VDF-TrFE) flexible membrane takes the form of A∝f0.04077E00.39748 in stage III of high electric fields. Nevertheless, for BiFeO3-embedded P(VDF-TrFE) [BFO/P(VDF-TrFE)] flexible membranes, the relations are developed as A∝f−0.3326E02.74911 in the low electric fields of stage I and as A∝f0.04309E01.04872 in stage III separately. The negative α indicates that more and more domain reversal lags behind the alternating periodic electric field in stage I. Instead, in stage III, the positive α indicates that most domain reversals can occur anytime whatever the alternating speed of electric fields is. Analogously, the positive β indicates that at any selected frequency, domains can flip at an external electric field. Abnormally, for the pristine P(VDF-TrFE) membrane, the scaling relation in the first E0 stage is broken, reflecting only dielectric contributions this time. The dynamic scaling data are significant for the micromechanism accomplishments of copolymers and for the designs of flexible electric devices.
The construction and legitimation of Elisa Loncón as a Mapuche female political leader on Instagram
Authors: Pérez-Arredondo Carolina , Cárdenas-Neira Camila , Cárcamo-Ulloa Luis
Published: November 2023

This study analyzed the multimodal discursive strategies Elisa Loncón, a Mapuche linguist and renowned academic,
used on Instagram to position herself as a sociopolitical leader during her tenure as president of the Chilean Constitutional
Convention. 811 Instagram posts from her account were downloaded from 15 January 2021 until 15 January 2022. From this, 81 of the
most interacted posts were selected and used to examine her multimodal discursive strategies while drawing on the
Discourse-Historical Approach (Reisigl and Wodak 2001, 2016). The results revealed three main themes: (1) the construction of an alternative leadership, (2)
visibilization of female leadership decision-making, and (3) a vindication of linguistic rights. Referential and intensification
strategies were particularly salient, and they were used to legitimize her role and foreground her Mapuche ancestry. These
findings highlight how female political leaders (and their intersecting identities) strategically deploy their communication
practices to resist sexism and racism.
Self-promotion, ideology and power in the social media posts of Nigerian Female Political Leaders
Authors: Igwebuike Ebuka Elias , Chimuanya Lily
Published: November 2023

This article examines how Nigerian female political leaders (NFPLs) exploit self-presentation strategies to
formulate and promote social justice. Using insights from critical discourse analysis and Jones and Pittman’s (1982) self-presentation strategies, and with a data set from the verified Facebook and Twitter
accounts of two female ministers and three female senators, the study investigates how NFPLs systematically utilize discursive
strategies such as self-promotion, ingratiation, exemplification, intimidation and supplication to present themselves as a
powerful voice for the voiceless and as active alternative leaders. The study argues that the strategies help the leaders to
amplify their authority by showcasing personal presence and past accomplishments, appealing to the concerns of the masses and
soliciting their support in future elections. The study demonstrates that these strategies project female leaders as dynamic
participants in political and public decision-making processes and positively evaluate their contributions to social change.
Patterns of Mental Health Service Contacts for Young People Deemed Eligible for Court Diversion
Authors: Marr Carey , Singh Sara , Gaskin Claire , Kasinathan John , Lloyd Trisha , Dean Kimberlie
Published: November 2023

Past research suggests that diverting young people away from the criminal justice system and into mental health services can reduce subsequent reoffending, but the impact of such programs on the rates of timely mental health service contact are largely unknown. In this study, we examined a sample of 523 young people who were deemed eligible for mental health diversion between 2008 and 2015. Around half (47%) of these young people were granted diversion by a Magistrate. Overall, the levels of timely mental health service contact after court finalization, even for those who were granted diversion, appeared low given that the purpose of diversion is to facilitate such contact for all those diverted. Specifically, only 22% of those who were granted community-based diversion and 62% of individuals granted inpatient-based diversion had mental health service contact within 7 days of court finalization. Rates of health contact were much lower for those who were not granted either type of diversion (8% and 23%, respectively). Diversion was associated with a significant reduction in reoffending rates, but the impact of early mental health service contact was less clear. There is a need to understand the reasons why many young people are not accessing appropriate mental health services following diversion in order to improve outcomes and fully realize the intended benefits of mental health court diversion.
The mechanism of Atg15-mediated membrane disruption in autophagy
Authors: Kagohashi Yoko , Sasaki Michiko , May Alexander I. , Kawamata Tomoko , Ohsumi Yoshinori
Published: November 2023

Autophagy is a lysosomal/vacuolar delivery system that degrades cytoplasmic material. During autophagy, autophagosomes deliver cellular components to the vacuole, resulting in the release of a cargo-containing autophagic body (AB) into the vacuole. AB membranes must be disrupted for degradation of cargo to occur. The lipase Atg15 and vacuolar proteases Pep4 and Prb1 are known to be necessary for this disruption and cargo degradation, but the mechanistic underpinnings remain unclear. In this study, we establish a system to detect lipase activity in the vacuole and show that Atg15 is the sole vacuolar phospholipase. Pep4 and Prb1 are required for the activation of Atg15 lipase function, which occurs following delivery of Atg15 to the vacuole by the MVB pathway. In vitro experiments reveal that Atg15 is a phospholipase B of broad substrate specificity that is likely implicated in the disruption of a range of membranes. Further, we use isolated ABs to demonstrate that Atg15 alone is able to disrupt AB membranes.
Creep in 0.91(Na1/2Bi1/2)TiO3-0.06BaTiO3-0.03K0.5Na0.5NbO3 lead-free piezoceramic under constant electric field loads
Authors: Chen Di , Ayrikyan Azatuhi , Chu Xiangcheng , Kamlah Marc , Webber Kyle G
Published: November 2023

This work explores the creep behavior of polycrystalline 0.91(Na1/2Bi1/2)TiO3-0.06BaTiO3-0.03K0.5Na0.5NbO3 under constant electric fields. It reveals intriguing time-dependent variations in both polarization and strain response, which can be attributed to a transformation from the relaxor state to a long-range ferroelectric order. Meanwhile, bulk volume resistivity values are obtained to eliminate the influence of leakage current on the polarization assessment. The findings provide valuable insights into the creep behavior of lead-free relaxor ferroelectrics, laying a solid foundation for enhancing the performance and reliability of piezoactuators.
Splitting phenomenon of ferromagnetic resonance spectra in NiFe films deposited on periodically rippled sapphire substrates
Authors: Xu Xu , Zheng Lei , Jin Lichuan , Wen Tianlong , Liao Yulong , Tang Xiaoli , Li Yuanxun , Zhong Zhiyong
Published: November 2023

The splitting phenomenon of ferromagnetic resonance (FMR) spectra of Ni80Fe20 (NiFe) films deposited on periodically rippled sapphire substrates is studied experimentally with the help of micromagnetic simulation. The analyses show that the splitting of FMR spectra is related to the periodic ripple topography of films. When the applied magnetic field is perpendicular to the ripple direction, the effective field of periodically rippled films becomes inhomogeneous. The splitting of FMR spectra originates from localized FMR peaks corresponding to different regions with different effective field intensities in the rippled structure. Furthermore, the relative intensity and position between the split mode and the main FMR mode can be changed by designing ripple topography. This work would help understand the splitting phenomenon of FMR spectra for magnetic thin films deposited on the periodically rippled sapphire substrates.
Effect of substituting on the transition dipole moment of the double perovskite Cs2AgInCl6
Authors: Zhang Lu-lu , Luo Jun , Liu Biao , Yang Junliang , Cai Meng-Qiu
Published: November 2023

The all-inorganic double perovskite Cs2AgInCl6 with three dimensional structure has attracted much attention due to its direct bandgap property and particular luminescence mechanism, which is self-trapped exciton emission. However, it is a pity that Cs2AgInCl6 exhibits low photoluminescence quantum yield, which affects its application for light-emitting devices. In this paper, the band structure and transition dipole moment of Cs2AgIn(1−x)Sb
x
Cl6 (x = 0, 0.25, 0.5, 0.75) are calculated using first principle calculation. The calculated results shows that the pure material Cs2AgInCl6 not only has a large band gap but also has the dipole forbidden transition, which means that the electrons cannot be excited from the valence band maximum to the conduction band minimum. However, the substituted Cs2AgIn0.75Sb0.25Cl6 have a good property for the band gap about 3.066 eV and break forbidden transition at point X. The reason for its change is due to the overlap of electron and hole for charge density. Our work provides theoretical guidance for the design of more efficient light-emitting devices.
Self-sensing ultra-high performance concrete: a review
Authors: Guo Yixuan , Wang Dongyu , Ashour Ashraf , Ding Siqi , Han Baoguo
Published: November 2023

Ultra-high performance concrete (UHPC) is an innovative cementitious composite, that has been widely applied in numerous structural projects because of its superior mechanical properties and durability. However, ensuring the safety of UHPC structures necessitates an urgent need for technology to continuously monitor and evaluate their condition during their extended periods of service. Self-sensing UHPC (SSUHPC) extends the functionality of UHPC system by integrating conductive fillers into the UHPC matrix, allowing it to address above demands with great potential and superiority. By measuring and analyzing the relationship between fraction change in resistivity and external stimulates (force, stress, strain), SSUHPC can effectively monitor the crack initiation and propagation as well as damage events in UHPC structures, thus offering a promising pathway for structural health monitoring (SHM). Research on SSUHPC has attracted substantial interests from both academic and engineering practitioners in recent years, this paper aims to provide a comprehensive review on the state of the art of SSUHPC. It offers a detailed overview of material composition, mechanical properties and self-sensing capabilities, and the underlying mechanisms involved of SSUHPC with various functional fillers. Furthermore, based on the recent advancements in SSUHPC technology, the paper concludes that SSUHPC has superior self-sensing performance under tensile load but poor self-sensing performance under compressive load. The mechanical and self-sensing properties of UHPC are substantially dependent on the type and dosage of functional fillers. In addition, the practical engineering SHM application of SSUHPC, particularly in the context of large-scale structure, is met with certain challenges, such as environment effects on the response of SSUHPC. Therefore, it still requires further extensive investigation and empirical validation to bridge the gap between laboratory research and real engineering application of SSUHPC.
Position measurement technology of boom-type roadheader based on binocular vision
Authors: Cheng Jiameng , Wang Dongjie , Zheng Weixiong , Wang Haixu , Shen Yang , Wu Miao
Published: November 2023

Positioning of underground mining equipment in coal mines is a primary challenge in the intelligent development of tunnel excavation. Accurate and reliable position measurement plays a crucial role in improving excavation efficiency. However, the stability and accuracy of traditional measurement methods are difficult to guarantee due to factors such as vibration, magnetic interference, and the absence of GPS signals in coal mine environments. To address the problem of unstable measurement of the boom-type roadheader‘s position, this paper proposes a binocular vision-based measurement technique that utilizes four light spots as characteristic points. By processing the target images captured by the binocular camera and combining the minimum bounding rectangle and ellipse fitting of the spot regions, the method successfully obtains the four light spot characteristics. Subsequently, precise matching and stereo distance measurement of the target in the left and right images enable the determination of the boom-type roadheader’s posi-tion information. A positioning platform based on binocular vision is built and experimentally evaluated. The results demonstrate that this method can achieve accurate spot extraction and stable measurement of the machine’s position, even in complex backgrounds such as mixed lighting and low illumination. The planar measurement errors within a distance range of 50 m are all within ±25 mm, which basically meets the required construction precision for tunnel excavation.
Non-enzymatic glucose detection with screen-printed chemiresistive sensor using green synthesised silver nanoparticle and multi-walled carbon nanotubes-zinc oxide nanofibers
Authors: Zalke Jitendra B , Narkhede N P , Pandhurnekar C P , Rotake Dinesh R , Singh Shiv Govind
Published: November 2023

Non-enzymatic screen-printed chemiresistive interdigitated electrodes (SPCIE) were designed and fabricated using a low-cost screen-printing method for detection of the glucose. The interdigitated electrodes (IDE) pattern was printed using conductive graphene ink on the glossy surface of the photo paper. The proposed glossy photo paper-based SPCIE are functionalized with multi-walled carbon nanotubes-zinc oxide (MWCNTs-ZnO) nanofibers to create the chemiresistive matrix. Further, to bind these nanofibers with the graphene electrode surface, we have used the green synthesized silver nanoparticles (AgNPs) with banana flower stem fluid (BFSF) as a binder solution. AgNPs with BFSF form the conductive porous natural binder layer (CPNBL). It does not allow to increase the resistivity of the deposited material on graphene electrodes and also keeps the nanofibers intact with paper-based SPCIE. The synthesized material of MWCNT-ZnO nanofibers and green synthesized AgNPs with BFSF as a binder were characterized by Ultraviolet-visible spectroscopy (UV–vis), scanning electron microscope (SEM), x-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). The amperometric measurements were performed on the proposed SPCIE sensor to detect the glucose sample directly. The innovative paper-based SPCIE glucose sensor exhibits a linear corelation between current measurements and glucose concentration in the range between 45.22 μm and 20 mm, with a regression coefficient (R
2) of 0.9902 and a lower limit of detection (LoD) of 45.22 μm (n = 5). The sensitivity of the developed SPCIE sensor was 2178.57 μAmM−1cm−2, and the sensor’s response time determined was approximately equal to 18 s. The proposed sensor was also tested for real blood serum sample, and relative standard deviation (RSD) was found equal to 2.95%.
Atypical architectural distortion detection in digital breast tomosynthesis: a multi-view computer-aided detection model with ipsilateral learning
Authors: Pan Jiawei , He Zilong , Li Yue , Zeng Weixiong , Guo Yaya , Jia Lixuan , Jiang Hai , Chen Weiguo , Lu Yao
Published: November 2023

Objective. Breast architectural distortion (AD), a common imaging symptom of breast cancer, is associated with a particularly high rate of missed clinical detection. In clinical practice, atypical ADs that lack an obvious radiating appearance constitute most cases, and detection models based on single-view images often exhibit poor performance in detecting such ADs. Existing multi-view deep learning methods have overlooked the correspondence between anatomical structures across different views. Approach. To develop a computer-aided detection (CADe) model for AD detection that effectively utilizes the craniocaudal (CC) and mediolateral oblique (MLO) views of digital breast tomosynthesis (DBT) images, we proposed an anatomic-structure-based multi-view information fusion approach by leveraging the related anatomical structure information between these ipsilateral views. To obtain a representation that can effectively capture the similarity between ADs in images from ipsilateral views, our approach utilizes a Siamese network architecture to extract and compare information from both views. Additionally, we employed a triplet module that utilizes the anatomical structural relationship between the ipsilateral views as supervision information. Main results. Our method achieved a mean true positive fraction (MTPF) of 0.05–2.0, false positives (FPs) per volume of 64.40%, and a number of FPs at 80% sensitivity (FPs@0.8) of 3.5754; this indicates a 6% improvement in MPTF and 16% reduction in FPs@0.8 compared to the state-of-the-art baseline model. Significance. From our experimental results, it can be observed that the anatomic-structure-based fusion of ipsilateral view information contributes significantly to the improvement of CADe model performance for atypical AD detection based on DBT. The proposed approach has the potential to lead to earlier diagnosis and better patient outcomes.
Experimental evidence of very short power decay lengths in H-mode discharges in the COMPASS tokamak
Authors: Hecko J , Komm M , Sos M , Adamek J , Bilkova P , Bogar K , Bohm P , Jaulmes F , Mysiura I , Tomes M , Vondracek P , Hron M , Panek R ,   COMPASS Team
Published: November 2023

Analysis of heat fluxes in scrape-off layer (SOL) plasma is important for the prediction of divertor tile heat loads in future reactor-sized tokamak machines. Typically, the radial heat flux profile can be accurately characterized by the decay length parameter λ

q
. The predictions are then based on the dependence of λ

q
on plasma and machine parameters. In recent years, several empirical scaling models were derived from a collective database of decay lengths observed in several large tokamaks as well as two spherical tokamaks. Most recently, a report from the TCV tokamak showed a deviation from several of the proposed models (Maurizio et al (TCV team) 2021 Nucl. Fusion
61 024003). In this work,

∼

100

edge plasma profiles of ELMy H-mode discharges were collected from the COMPASS tokamak database for heat flux analysis. The COMPASS tokamak has a similar machine size and plasma parameters to the TCV tokamak, offering a valuable comparison. The λ

q
was measured in both downstream and upstream SOL utilizing a divertor probe array validated by an IR camera and Thomson scattering diagnostics. A comparison with the predictions of several scaling models indicated an occurrence of anomalously short (by a factor of 2–5) inter-ELM power decay lengths in both upstream and downstream, as well as a difference in λ

q
between these two regions. Possible causes related to the accuracy of magnetic reconstruction were eliminated and physics-based sources of apparent compression effects were hypothesized as a motivation for future research.
Carbon monoxide ionization in femtosecond bicircular laser pulses
Authors: Cristian Stroe Marius , Fifirig Magda
Published: November 2023

The CO ionization by 7.8 fs bicircular laser field consisting of the coherent superposition of two coplanar circularly polarized laser pulses is studied in the framework of the time-dependent Hartree–Fock method. Six different superpositions composed of a near-infrared pulse with wavelength of 780 nm and an ultraviolet pulse with wavelength ranging from 244 to 390 nm are considered. The intensity of the near-infrared laser pulse is 1.0 × 1014 W cm−2 and the intensity of the ultraviolet laser pulse runs from 5.0 × 1013 to 2.0 × 1014 W/cm2. Numerical results reveal that the ionization probabilities for counter-rotating field are enhanced compared to the ionization probabilities for co-rotating field only for the coherent superposition of 780 and 390 nm circularly polarized laser pulses. Our computations also emphasize that the highest occupied molecular orbital mainly contributes to CO ionization. The contribution of the inner valence molecular orbitals can be significantly increased by adjusting the intensity ratio and the relative phase between the two colors. Note that the co-rotating laser field consisting of the coherent superposition of two circularly polarized laser pulses of wavelengths 780 and 390 nm yields higher ionization probability when the positive direction of the electric field component along molecular axis points to the O nucleus.
Enhancement of electron transport mobility in GaAs/InGaAs asymmetrically doped narrow quantum well pHEMT structure
Authors: Panda Sangita R , Pradhan Manoranjan , Sahu Trinath , Panda Ajit Kumar
Published: November 2023

We study the effect of asymmetric doping concentrations on the electron mobility μ in GaAs/InGaAs-based single quantum well (SQW) as well as double quantum well (DQW) pseudomorphic high electron mobility transistor (pHEMT) structures. Unequal doping in the substrate and surface barriers (n

d1
and n

d2
) causes asymmetric distributions of subband wave functions, ψ

0
and ψ

1, which influence the subband scattering rate matrix elements (SSRME), thereby affecting the subband mobility μ

n
. For narrow well widths (w

w
), in SQW structures, mostly a single subband is occupied. We show that an increase in n

d2
, keeping n

d1
fixed, enhances μ nonlinearly. The interface roughness (ir-) scattering mostly dominates μ in thin wells (w

w
< 70 Å), while generally, μ is determined by ionized impurity (ii-) scattering and to some extent by alloy disorder (ad-) scattering. The influence of ir-scattering enhances, while ad-scattering diminishes, by reducing n

d2
. For DQW, a double subband is occupied. In a symmetric DQW structure at resonance, n

d1
= n

d2
, ψ

0
and ψ

1
equally extend into both the wells. For a minor variation, say n

d1
> n

d2
, ψ

0
mostly lies in one well while ψ

1
is in the other well. In the case of n

d1
< n

d2
, the distribution reverts. The substantial changes in ψ

0
and ψ

1
influence the intra- and inter-SSRME differently through intersubband effects, leading to nonlinear μ

n
as a function of n

d2
. Taking n

d1
+ n

d2
= 3 × 1018 cm−3, we show that for w

w1
= w

w2
= 80 Å, a shallow dip in μ occurs at n

d1
= n

d2
= 1.5 × 1018 cm−3. Whereas, for w

w1
= 60 Å and w

w2
= 100 Å, the dip in μ occurs near the corresponding resonance, n

d1
= 2.3 × 1018 cm−3 and n

d2
= 0.7 × 1018 cm−3. Our results of nonlinear μ can be utilized for performance analysis of pHEMT.
Impact of sputtering gas on the microstructural, mechanical and wetting properties of vanadium nitride coatings
Authors: Rao Akula Umamaheswara , Tiwari Sunil Kumar , Kharb Archana Singh , Chawla Vipin , Dubey Paritosh , Goyat Manjeet Singh , Saxena Vikas , Chawla Amit Kumar
Published: November 2023

Vanadium nitride (VN) coatings were deposited via reactive DC magnetron sputtering technique on a hot substrate (400 °C) with varying partial pressure of N2. The impact of nitrogen partial pressure on the crystal structure, microstructure, elemental composition, surface topography, mechanical and wetting properties of VN coatings was investigated using grazing incidence X-ray diffraction (GIXRD), Raman spectroscopy, field emission scanning electron microscope (FESEM), energy dispersive spectroscopy (EDS), atomic force microscope (AFM), nano-indentation, and drop shape analyzer (DSA). The variation in the N2 partial pressure leads the significant changes in the microstructure, mechanical and wetting properties of the coatings. The GIXRD spectra reveals the formation of crystalline FCC phase in the deposited VN coatings. However, at 100% N2 partial pressure, the preferred orientation of crystal planes changes from (200) to (220). The FESEM image reveals that at low N2 partial pressure, the coating exhibits well-separated grains with clearly visible grain boundaries. As the N2 partial pressure increases, the agglomeration of grains becomes more pronounced, and the grain boundaries become less discernible. However, at 100% N2 partial pressure, the structure transforms into triangular nanoflake-like prismatic structures with voids. The VN coatings with 60% N2 partial pressure exhibits the highest mechanical properties whereas at 100% N2 partial pressure, the VN coatings reveal super-hydrophilic character.
Exploring the potential of GeTe for the application in Thermophotovoltaic (TPV) cell
Authors: Abir Ahnaf Tahmid , Mondal Bipanko Kumar , Hossain Jaker
Published: November 2023

Germanium telluride (GeTe) having a direct bandgap of 0.6 eV has mainly been used in phase change memory and thermoelectric power generation. In this article, we study the electronic structure of the GeTe by first-principles calculations. The theoretical direct bandgap of GeTe was found to be 0.69 eV which is very close to the experimental value. Then, we demonstrated a single-junction GeTe thermophotovoltaic (TPV) cell based on device transport model with np structure at the black body and cell temperature of 1775 and 300 K, respectively. The device was optimized for the higher performance of the TPV cell. The GeTe TPV cell exhibited an efficiency of 7.9% with JSC = 16.16 A cm−2, VOC = 0.360 V and FF = 75.51%, respectively. These results indicate that GeTe could be a promising material for the fabrication of efficient TPV cell.
Influence of substitutional defects on the structural and magnetic properties of barium hexaferrites
Authors: Aladerah Bilal , Gharaibeh Maen , Obeidat Abdalla
Published: November 2023

A computational analysis is conducted to understand the impact of Al and Sr substitutions on the structural and magnetic properties of M-type barium hexaferrite (BaFe12O19 or BFO). Al substitutions in BFO led to concentration-dependent increases in lattice parameters and magnetocrystalline anisotropy energy (

E

MCA

), while the magnetic moment showed a decline. In contrast, Sr substitutions influenced the lattice differently, reducing parameters but enhancing both

E

MCA

and the spin magnetic moment, especially under varying Coulomb interaction (

U

eff

) conditions. It’s noteworthy that the

E

MCA

value reached approximately 1.03 meV with full Sr substitution. Furthermore, SrFe12O19 (SFO) consistently outperformed BFO in terms of exchange interaction parameters. These findings offer valuable insights for the development and optimization of next-generation magnetic materials.
Modulation instability in a microresonator with graphene saturable absorber, frequency selective feedback and external potential
Authors: Saini Anjali , Jana Soumendu
Published: November 2023

Modulation Instability is studied in the presence of an external periodic potential in microresonator comprising of a vertical cavity surface emitting laser with saturable absorber and frequency selective feedback. The role of intensity of input field, pump parameter, diffraction coefficient and saturable absorption on the modulation instability has been investigated. Thus, Modulation instability can be tuned by varying the system parameters. This aspect would be beneficial for the purpose of encryption. It is also observed that modulation instability is not explicitly dependent on externally applied potential whereas the effect of potential is shown implicitly by using numerical analysis. The presence of an external potential give the operating range of resonance frequency of the optical cavity instead of one value at the same system parameters. This operating range of resonance frequency is spatially dependent and varies with the system parameters.
Simulational and theoretical study of electron scattering cross section by Chlormethine-DNA complex
Authors: Ashouri Marjan , Hajivaliei Mahdi , Gholami Nasim , Ebadi Ahmad
Published: November 2023

Studying phenomena happening in therapies to conquer cancer has been the aim of extensive research projects in recent years. One of the most practical treatments is utilizing electrons as interacting particles in body tissues. So, studying electron interactions with biological molecules is highly important. Chlormethine as an alkylating agent has always been used since the initial era of cancer chemotherapy. The drug makes interstrand and intrastrand covalent cross-links between two constituents in DNA. In this paper the physical interaction of electrons with Chlormethine drug was reported for the first time. Molecular dynamic (MD) simulations and free energy calculations were carried out to investigate near approach binding of the drug with DNA. Electron scattering cross sections on the system of DNA bases along with Chlormethine as an anticancer drug taken from MD simulations are studied in this paper. Calculations include relativistic Dirac partial-wave which is combined with a local interaction potential. Electron scattering is modelled by the independent atom model (IAM) considering a screening corrected coefficient over an energy range.
A trivalent ferrite ferrofluid compound’s rheological response to angular frequency, magnetic induction and shear induction of chain clusters
Authors: Abideen A Ibiyemi , Pant R P
Published: November 2023

At low and high temperatures in the presence and absence of magnetic fields, the effects of shear rate, angular frequency, and shear strain on the rheological characteristics of zinc ferrite ferrofluid is investigated. Chemical co-precipitation was used to create a zinc ferrite ferrofluid that was then coated with oleic acid to improve the stability of the fluid’s particles and avoid particle agglomeration. We looked at the rheological characteristics caused by the induced magnetic field, such as the shear stress, complex viscosity, storage modulus, loss modulus, relaxation modulus, viscous torque, damping factor, and figure of merit. From the analysis of time dependent relaxation modulus, a steady-state rheological system is formed at time interval beyond 50 s. As the shear and complex viscosities increase with an increase in magnetic field and a decrease in temperature, obstruction to fluid flow is produced. When a rheological system operates at low angular frequency and high shear rate, high shear stress is loaded; when it operates at high angular frequency and low shear rate, low shear stress is loaded. In the absence of magnetic field, a low viscosity 0.425 Pa.s and shear force 46 Pa were formed, while high viscosity 8.140 Pas and shear stress 168 Pa were formed when magnetic field 1.000 Tesla was applied. The oscillatory mode test demonstrates a change in structure from solid to liquid due to the establishment of a crossover point between shear strain 55 and 64%, supporting the solid–liquid phase transition behavior. The damping analysis demonstrates that the system is in fact excessively dampened, and it may now be utilized to reduce vibrations in a system. The system is really overdamped showing a maximum damping factor 2.08, according to the damping study, and can therefore be used to reduce vibrations in other systems. The fluid exhibits non-Newtonian shear-thinning behavior as shear rates increase. A high viscous torque is created at low shear strain and high angular frequency, which leads to the creation of a strong rotating magnetic field.
Active Disturbance Rejection-based Double-loop Control Design for Large Antenna's Servo System
Authors: Li Ning , Wang Na , Liu Zhiyong , Yang Lei
Published: November 2023

Radio astronomical observations put stringent requirements on the tracking and pointing accuracy of radio telescope antennas. High inertia, low stiffness, underdamped, and multi-resonant frequencies of a large aperture radio telescope’s antenna make the high-accuracy control difficult. It is not easy to satisfy control performance using only conventional PID controllers. A low-order Active Disturbance Rejection-based double-loop controller for large antenna is designed in this paper and tested on the Green Bank Telescope model. First, the first-order Linear Active Disturbance Rejecting Controller (LADRC) cascading a first-order low-pass filter and a notch filter is designed for the antenna’s velocity loop to achieve the dual-objective optimal velocity tracking. Second, the position loop controller is designed to realize the antenna’s position-tracking control by combining the PD controller and a low-pass filter. Further optimization of the position-loop controller helps improve the dynamic performance of the system. The simulation results indicate that the response curves of the proposed PD-LADRC control are smother than those of the Quantitative Feedback Theory (QFT) based controller; the settling time of the PD-LADRC system is 10.1 s and reduces by about 8.2 s than that of the QFT. While using a better position controller reduces settling time to 5 s. The PD-LADRC system also has better wind-disturbance rejection; the worst disturbance response reduces at the gearbox by 68.3% and 60% at the dish, and the recovery time reduces by more than 15 s than the QFT-based controller. In addition, besides easier parameter tuning, the proposed PD-LADRC has better robustness to systematic parameter perturbations and minor tracking error rms in position tracking.
Analytical solutions to the precession relaxation of magnetization with uniaxial anisotropy
Authors: Zhang 张 Ze-Nan 泽南 , Jia 贾 Zhen-Lin 镇林 , Xue 薛 De-Sheng 德胜
Published: November 2023

Based on the Landau–Lifshitz–Gilbert (LLG) equation, the precession relaxation of magnetization is studied when the external field
H
is parallel to the uniaxial anisotropic field
H

k. The evolution of three-component magnetization is solved analytically under the condition of H = nH
k (n = 3, 1 and 0). It is found that with an increase of
H
or a decrease of the initial polar angle of magnetization, the relaxation time decreases and the angular frequency of magnetization increases. For comparison, the analytical solution for H
k = 0 is also given. When the magnetization becomes stable, the angular frequency is proportional to the total effective field acting on the magnetization. The analytical solutions are not only conducive to the understanding of the precession relaxation of magnetization, but also can be used as a standard model to test the numerical calculation of LLG equation.
Recent progress on ambipolar 2D semiconductors in emergent reconfigurable electronics and optoelectronics
Authors: Zhao 赵 Yuehao 月豪 , Sun 孙 Haoran 浩然 , Sheng 盛 Zhe 喆 , Zhang 张 David Wei 卫 , Zhou 周 Peng 鹏 , Zhang 张 Zengxing 增星
Published: November 2023

In these days, the increasing massive data are being produced and demanded to be processed with the rapid growth of information technology. It is difficult to rely solely on the shrinking of semiconductor devices and scale-up of the integrated circuits (ICs) again in the foreseeable future. Exploring new materials, new-principle semiconductor devices and new computing architectures is becoming an urgent topic in this field. Ambipolar two-dimensional (2D) semiconductors, possessing excellent electrostatic field controllability and flexibly modulated major charge carriers, offer a possibility to construct reconfigurable devices and enable the ICs with new functions, showing great potential in computing capacity, energy efficiency, time delay and cost. This review focuses on the recent significant advancements in reconfigurable electronic and optoelectronic devices of ambipolar 2D semiconductors, and demonstrates their potential approach towards ICs, like reconfigurable circuits and neuromorphic chips. It is expected to help readers understand the device design principle of ambipolar 2D semiconductors, and push forward exploring more new-principle devices and new-architecture computing circuits, and even their product applications.
Molecular dynamics simulation of the flow mechanism of shear-thinning fluids in a microchannel
Authors: Yang 杨 Gang 刚 , Zheng 郑 Ting 庭 , Cheng 程 Qihao 启昊 , Zhang 张 Huichen 会臣
Published: November 2023

Shear-thinning fluids have been widely used in microfluidic systems, but their internal flow mechanism is still unclear. Therefore, in this paper, molecular dynamics simulations are used to study the laminar flow of shear-thinning fluid in a microchannel. We validated the feasibility of our simulation method by evaluating the mean square displacement and Reynolds number of the solution layers. The results show that the change rule of the fluid system’s velocity profile and interaction energy can reflect the shear-thinning characteristics of the fluids. The velocity profile resembles a top-hat shape, intensifying as the fluid’s power law index decreases. The interaction energy between the wall and the fluid decreases gradually with increasing velocity, and a high concentration of non-Newtonian fluid reaches a plateau sooner. Moreover, the velocity profile of the fluid is related to the molecule number density distribution and their values are inversely proportional. By analyzing the radial distribution function, we found that the hydrogen bonds between solute and water molecules weaken with the increase in velocity. This observation offers an explanation for the shear-thinning phenomenon of the non-Newtonian flow from a micro perspective.
Unraveling the molecular mechanism of prion disease: Insights from α2 area mutations in human prion protein
Authors: Tan 谈 Rongri 荣日 , Xia 夏 Kui 奎 , Xun 寻 Damao 大毛 , Zong 宗 Wenjun 文军 , Yu 余 Yousheng 幼胜
Published: November 2023

Prion diseases are a class of fatal neurodegenerative diseases caused by misfolded prion proteins. The main reason is that pathogenic prion protein has a strong tendency to aggregate, which easily induces the damage to the central nervous system. Point mutations in the human prion protein gene can cause prion diseases such as Creutzfeldt–Jakob and Gerstmann’s syndrome. To understand the mechanism of mutation-induced prion protein aggregation, the mutants in an aqueous solution are studied by molecular dynamics simulations, including the wild type, V180I, H187R and a double point mutation which is associated with CJD and GSS. After running simulations for 500 ns, the results show that these three mutations have different effects on the kinetic properties of PrP. The high fluctuations around the N-terminal residues of helix 2 in the V180I variant lead to a decrease in hydrogen bonding on helix 2, while an increase in the number of hydrogen bonds between the folded regions promotes the generation of β-sheet. Meanwhile, partial deletion of salt bridges in the H187R and double mutants allows the sub-structural domains of the prion protein to separate, which would accelerate the conversion from PrPC to PrPSc. A similar trend is observed in both SASA and Rg for all three mutations, indicating that the conformational space is reduced and the structure is compact.
Enhanced conductivity and weakened magnetism in Pb-doped Sr2IrO4
Authors: Yue 岳 Zhi-Lai 智来 , Zhen 甄 Wei-Li 伟立 , Niu 牛 Rui 瑞 , Jiao 焦 Ke-Ke 珂珂 , Zhu 朱 Wen-Ka 文卡 , Pi 皮 Li 雳 , Zhang 张 Chang-Jin 昌锦
Published: November 2023

Group IV element Pb has been selected as the dopant to dope at the Sr site of Sr2IrO4. It is exciting to find that the single-phase crystal structure could be maintained with a high Pb doping level of up to x = 0.3 in Sr2−x
Pb
x
IrO4. The mapping data obtained from energy-dispersive x-ray spectroscopy analyses give solid evidence that the Pb ions are uniformly distributed in the Sr2IrO4 matrix. The incorporation of Pb leads to a moderate depression of the canted antiferromagnetic ordering state. The electrical conductivity could be greatly enhanced when the Pb doping content is higher than x = 0.2. The present results give a fresh material base to explore new physics in doped Sr2IrO4 systems.
A Cross-matching Service for Data Center of Xinjiang Astronomical Observatory
Authors: Zhang Hai-Long , Wang Jie , Ye Xin-Chen , Wang Wan-Qiong , Li Jia , Zhang Ya-Zhou , Du Xu , Wu Han , Zhang Ting
Published: November 2023

Cross-matching is a key technique to achieve fusion of multi-band astronomical catalogs. Due to different equipment such as various astronomical telescopes, the existence of measurement errors, and proper motions of the celestial bodies, the same celestial object will have different positions in different catalogs, making it difficult to integrate multi-band or full-band astronomical data. In this study, we propose an online cross-matching method based on pseudo-spherical indexing techniques and develop a service combining with high performance computing system (Taurus) to improve cross-matching efficiency, which is designed for the Data Center of Xinjiang Astronomical Observatory. Specifically, we use Quad Tree Cube to divide the spherical blocks of the celestial object and map the 2D space composed of R.A. and decl. to 1D space and achieve correspondence between real celestial objects and spherical patches. Finally, we verify the performance of the service using Gaia 3 and PPMXL catalogs. Meanwhile, we send the matching results to VO tools-Topcat and Aladin respectively to get visual results. The experimental results show that the service effectively solves the speed bottleneck problem of cross-matching caused by frequent I/O, and significantly improves the retrieval and matching speed of massive astronomical data.